阅读说明：本技术 一种超低温风冷模块机补气增焓控制系统及控制方法 (Air supplementing and enthalpy increasing control system and control method of ultralow-temperature air-cooled modular machine ) 是由 韩鑫 于 2021-05-28 设计创作，主要内容包括：本发明提供了一种超低温风冷模块机补气增焓控制系统及控制方法,包括环境温度传感器、压缩机排气温度传感器、设有电子膨胀阀的辅回路,所述辅回路上设置有EVI蒸发温度传感器和EVI补气温度传感器,在排气温度较低时,采用分段EVI过热度控制,不同排气温度区间设定不同EVI过热度,保证压缩机合理补气量同时确保辅回路电子膨胀阀稳定控制；当排气温度继续升高时超过进排气温度变化率控制温度,采用排气温度变化率控制,此时辅回路电子膨胀阀开度根据排气温度变化率进行控制,同时将环境温度与出水温度对压缩机运行的影响也考虑在。本发明所述的分段EVI过热度控制和排气温度变化率控制结合以保证风冷模块机稳定运行也可应用于更多恶劣环境。(The invention provides an air-supplying and enthalpy-increasing control system and a control method for an ultralow-temperature air-cooling modular machine, which comprises an environment temperature sensor, a compressor exhaust temperature sensor and an auxiliary loop provided with an electronic expansion valve, wherein the auxiliary loop is provided with an EVI evaporation temperature sensor and an EVI air-supplying temperature sensor; when the exhaust temperature continuously rises and exceeds the inlet and exhaust temperature change rate control temperature, the exhaust temperature change rate control is adopted, the opening degree of the auxiliary loop electronic expansion valve is controlled according to the exhaust temperature change rate, and meanwhile, the influence of the ambient temperature and the outlet water temperature on the operation of the compressor is also considered. The sectional EVI superheat degree control and the exhaust temperature change rate control are combined to ensure that the air-cooled modular unit can stably run and can be applied to more severe environments.)

1. The utility model provides an ultra-low temperature forced air cooling module machine tonifying qi increases enthalpy control system which characterized in that: the system comprises a main loop (5), an auxiliary loop (6) and a four-way valve (2), wherein a first communication pipeline (21) is arranged between a second port and a third port of the four-way valve (2), and an air-supply enthalpy-increasing compressor (4) is arranged on the first communication pipeline;

one end of the main loop (5) is communicated with a first four-way valve port, the other end of the main loop is communicated with a fourth four-way valve port, and the main loop is further sequentially communicated with a finned tube type heat exchanger (9), a first economizer (3) chamber and a first heat exchange chamber of the heat exchanger (1);

the auxiliary loop (6) comprises an auxiliary loop I and an auxiliary loop II, the economizer is also provided with a cavity II, one end of the auxiliary loop I is communicated with the input end of the cavity I of the economizer, the other end of the auxiliary loop I is communicated with the input end of the cavity II of the economizer (3), one end of the auxiliary loop II is communicated with the output end of the cavity II of the economizer (3), and the other end of the auxiliary loop II is communicated with the compressor (4); an auxiliary circuit electronic expansion valve (61) and an EVI evaporation temperature sensor (62) are arranged on the auxiliary circuit I, and an EVI air supply temperature sensor (63) is arranged on the auxiliary circuit II.

2. The ultra-low temperature air-cooled modular machine air-supplying enthalpy-increasing control system according to claim 1, characterized in that: the heat exchanger is also provided with a heat exchange chamber II, the heat exchange chamber II is provided with a unit water outlet interface I and a unit water inlet interface II, the unit water outlet temperature sensor (11) is arranged on the interface I, and the unit water inlet temperature sensor (12) is arranged on the interface II;

the air inlet end of the air-supplying enthalpy-increasing compressor (4) is provided with a compressor air suction temperature sensor (41), and the air outlet end of the air-supplying enthalpy-increasing compressor (4) is provided with a compressor exhaust temperature sensor (42).

3. The control method of the air-supplying enthalpy-increasing control system of the ultralow-temperature air-cooling modular machine based on the claim 1 or 2 is characterized in that: the control method comprises a refrigeration mode control method and a heating mode control method, wherein the refrigeration mode control method and the heating mode control method are controlled through the following steps:

s1: the unit completes initialization after being electrified, and the compressor is started and operates the stable operation time t of the compressor starting after receiving the starting command_startJudging whether the condition for opening the auxiliary loop electronic expansion valve (61) is met or not;

s2: opening the auxiliary loop electronic expansion valve (61) to the heating initial opening U under the condition that the auxiliary loop electronic expansion valve (61) is opened_OHOr initial opening degree U of refrigeration_OCAnd continuously assisting the heating initial opening maintaining time t of the loop electronic expansion valve_OHOr initial refrigeration on maintaining time t_OC；

S3: after the auxiliary loop electronic expansion valve (61) meets the initial opening maintaining time, judging the environment temperature Ta and the compressor exhaust temperature Td again to determine a control method;

s4: and starting segmented EVI superheat degree control or exhaust temperature change rate control.

4. The air-supplying enthalpy-increasing control method for the ultralow-temperature air-cooling module machine, according to claim 3, is characterized in that: in step S2, the conditions for opening the auxiliary circuit electronic expansion valve (61) in the cooling mode are: ambient temperature T_aRefrigeration open auxiliary loop electronic expansion valve ring temperature T is not more than_aC-openCompressor discharge temperature T_dExhaust temperature T of electronic expansion valve with auxiliary loop opened at least_d-open；

In the heating mode, the conditions for opening the auxiliary circuit electronic expansion valve (61) are as follows: ambient temperature T_aRing temperature T of electronic expansion valve of heating open auxiliary loop_aH-openCompressor discharge temperature T_dExhaust temperature T of electronic expansion valve with auxiliary loop opened at least_d-open；

The ambient temperature T_aMeasured by an ambient temperature sensor (7), the compressor discharge temperature T_dMeasured by a compressor discharge temperature sensor; ring temperature T of electronic expansion valve of refrigeration open auxiliary loop_aC-openOpen auxiliary loop electronic expansion valve exhaust temperature T_d-openHeating open auxiliary loopElectronic expansion valve ring temperature T_aH-openAll are parameters set in the control program.

5. The air-supplying enthalpy-increasing control method for the ultralow-temperature air-cooling module machine, according to claim 3, is characterized in that: in step S3, in the cooling mode, the control method includes the following steps:

s301: firstly, the ambient temperature Ta is judged,

if the ambient temperature T_aThe conditions are satisfied: t is_aRing temperature T of electronic expansion valve for auxiliary circuit of refrigeration_aC-closeThe auxiliary loop electronic expansion valve (61) executes a valve closing action to close the opening of the auxiliary loop electronic expansion valve to 0pps, wherein the ring temperature T of the auxiliary loop electronic expansion valve is closed in the refrigeration process_aC-closeRing temperature T of electronic expansion valve for opening auxiliary circuit for refrigeration_aC-open；

If the ambient temperature T_aAnd (3) satisfying the following conditions: t is_aElectronic expansion valve ring temperature T of auxiliary circuit of refrigeration switch_aC-closeThen, the exhaust temperature T is performed again_dJudging;

s302: judging the exhaust temperature T_d，

If the compressor discharge temperature T_dThe conditions are satisfied: t is_dExhaust temperature T of electronic expansion valve of auxiliary circuit_d-closeAnd the delay t of the electronic expansion valve of the auxiliary loop is closed at low temperature by continuous temperature discharge_sovIf yes, the auxiliary circuit electronic expansion valve (61) executes a valve closing action to close the opening to 0 pps;

if the exhaust temperature of the compressor meets the condition: auxiliary circuit electronic expansion valve exhaust temperature T_d-close≤T_d< rate of change of intake and exhaust gas temperature control temperature T_d-onAt the moment, the auxiliary loop electronic expansion valve controls the EVI superheat degree in a subsection mode according to a refrigeration mode control method;

if the exhaust temperature of the compressor meets the condition: t is_dNot less than the temperature change rate control temperature T of the air inlet and exhaust_d-onAt the moment, the auxiliary loop electronic expansion valve (61) quits the EVI superheat degree control and controls the exhaust temperature change rate according to a refrigeration mode control method;

refrigeration auxiliary circuit electronic expansion valve ring temperature T_aC-closeElectronic expansion valve exhaust temperature T of auxiliary circuit_d-closeIntake/exhaust air temperature change rate control temperature T_d-onAll are parameters set in the control program.

6. The air-supplying enthalpy-increasing control method for the ultralow-temperature air-cooling module machine, according to claim 5, is characterized in that: in step 302, under the refrigeration mode, the segmented EVI superheat degree control method comprises the following steps:

if the exhaust temperature of the compressor meets the condition: auxiliary circuit electronic expansion valve exhaust temperature T_d-close≤T_dExhaust temperature T of electronic expansion valve with auxiliary circuit_d-openAt the moment, the auxiliary loop electronic expansion valve refrigerates the target superheat degree E according to EVI_C-set0Carrying out PID control;

if the exhaust temperature of the compressor meets the condition: open auxiliary loop electronic expansion valve exhaust temperature T_d-open≤T_d< target compressor discharge temperature 1T_d-obj1At the moment, the auxiliary loop electronic expansion valve refrigerates the target superheat degree E according to EVI_C-set1Carrying out PID control;

if the exhaust temperature of the compressor meets the condition: compressor target discharge temperature 1T_d-obj1≤T_d< target compressor discharge temperature 2T_d-obj2At the moment, the auxiliary loop electronic expansion valve refrigerates the target superheat degree E according to EVI_C-set2Carrying out PID control;

if the exhaust temperature of the compressor meets the condition: compressor target discharge temperature 2T_d-obj2≤T_d< rate of change of intake and exhaust gas temperature control temperature T_d-onAt the moment, the auxiliary loop electronic expansion valve refrigerates the target superheat degree E according to EVI_C-set3Carrying out PID control;

wherein the above EVI target superheat degree satisfies the condition: e_C-set0≥E_C-set1≥E_C-set2≥E_C-set3And the calculation mode of the actual superheat degree of the EVI is as follows:

EVI actual superheat degree E-EVI air supply temperature T_InjEVI Evaporation temperature T_Eva，

The exhaust temperature T of the electronic expansion valve of the auxiliary closing loop_d-closeOpen auxiliary loop electronic expansion valve exhaust temperatureT_d-openTarget compressor discharge temperature 1T_d-obj1Target compressor discharge temperature 2T_d-obj2Intake/exhaust air temperature change rate control temperature T_d-onAll the parameters are set by a control program, and the target superheat degree E of the EVI refrigeration is_C-set0(ii) a EVI refrigeration target superheat degree E_C-set1(ii) a EVI refrigeration target superheat degree E_C-set2(ii) a EVI refrigeration target superheat degree E_C-set3All are set parameters in a control program, and the EVI air supplement temperature T_InjMeasured by a gas supply temperature sensor (63), the EVI evaporation temperature T_EvaMeasured by an evaporation temperature sensor (62).

7. The air-supplying enthalpy-increasing control method for the ultralow-temperature air-cooling module machine, according to claim 5, is characterized in that: in step S302, in the cooling mode, the exhaust gas temperature change rate control method:

when exhaust temperature T_dThe change rate satisfies the condition:and then, calculating the opening degree change rate of the auxiliary loop electronic expansion valve according to the following formula:

when exhaust temperature T_dThe change rate satisfies the condition:and then, calculating the opening degree change rate of the auxiliary loop electronic expansion valve according to the following formula:

theta is the sampling period for calculating the exhaust gas temperature change rate when the compressor exhaust gas temperature T_dNot less than the temperature change rate control temperature T of the air inlet and exhaust_d-onThe exhaust temperature change rate is sampled at the beginning, and the exhaust temperature sampling calculation is carried out at intervals of theta, wherein T_d(n.theta) is the exhaust temperature value in the nth sampling period, T_d((n +1) · theta) is the exhaust temperature value in the (n +1) th sampling period;

the discharge temperature change rate calculated for the (n +1) th sampling period;

the opening change rate of the auxiliary loop electronic expansion valve calculated for the (n +1) th sampling period whenPerforming the action of opening the auxiliary circuit electronic expansion valve whenThe valve closing action is executed, and the opening degree U (n & theta) of the electronic expansion valve (61) of the previous auxiliary circuit is increasedOpening degree; when in useKeeping the current opening unchanged;

when in useWherein Δ U_max-openThe opening degree change rate of the auxiliary loop electronic expansion valve calculated in the (n +1) th sampling period at the time is the maximum valve opening step numberPerforming motion calculation;

when in useWherein Δ U_max-closeThe maximum valve closing step number is obtained, and the opening degree change rate of the auxiliary loop electronic expansion valve calculated in the (n +1) th sampling period at the moment is according toPerforming motion calculation;

the delta U_max-openAnd Delta U_max-closeThe opening and closing range of the valve body of the electronic expansion valve is set;

when the discharge temperature T of the compressor_dControlling temperature T from exceeding the rate of change of intake and exhaust temperatures_d-onThen, the temperature is reduced under the control action of the exhaust temperature change rate and is reduced to meet the conditions: t is_dControlling the temperature T at the temperature change rate of less than or equal to the exhaust gas temperature_d-offIf the auxiliary loop electronic expansion valve exits the exhaust gas temperature change rate control at the moment, the auxiliary loop electronic expansion valve enters the EVI superheat rate control, meanwhile, the exhaust gas temperature change rate sampling calculation is finished, and the exhaust gas temperature change rate control temperature T is_d-offThe conditions are satisfied: t is_d-obj1≤T_d-off≤T_d-obj2；

T_aC-standCorrecting the reference environment temperature for the environment temperature of the opening degree change rate of the electronic expansion valve of the refrigeration auxiliary loop, and setting parameters for a control program; t is_inC-standCorrecting the reference inlet water temperature for the inlet water temperature of the opening change rate of the electronic expansion valve of the refrigeration auxiliary loop, and setting parameters for a control program; t is_d-offControlling the temperature for the rate of change of the exhaust gas temperature, parameters set for the control program, k_C-addThe valve opening coefficient of the electronic expansion valve of the refrigeration auxiliary loop is set as a parameter of a control program; k is a radical of_C-subThe valve closing coefficient of the electronic expansion valve of the refrigeration auxiliary loop is set as a parameter of a control program; alpha is alpha_CThe parameter is set for the index correction coefficient of the refrigeration environment temperature and the control program; beta is a_CThe parameter is set for the index correction coefficient of the temperature of the cooling inlet water and the control program; if α is_CAnd beta_CWhen the values are all 0, the water inlet temperature and the environment temperature are not corrected.

8. The air-supplying enthalpy-increasing control method for the ultralow-temperature air-cooling module machine, according to claim 3, is characterized in that: in step S3, in the heating mode, the control method includes:

s311: firstly, the environmental temperature T is judged_a，

If the ambient temperature T_aThe conditions are satisfied: t is_aRing temperature T of electronic expansion valve for not less than heating auxiliary circuit_aH-closeThe auxiliary loop electronic expansion valve (61) executes a valve closing action to close the opening of the auxiliary loop electronic expansion valve to 0pps, wherein the auxiliary loop electronic expansion valve is heated and closed to reach the ring temperature T_aH-closeRing temperature T of electronic expansion valve for heating open auxiliary loop_aH-open；

If the ambient temperature T_aThe conditions are satisfied: t is_aElectronic expansion valve ring temperature T of auxiliary loop for heating_aH-closeThen, the exhaust temperature T is performed again_dJudging;

s312: judging the exhaust temperature T_d，

If the exhaust temperature of the compressor meets the condition: t is_dExhaust temperature T of electronic expansion valve of auxiliary circuit_d-closeAnd the delay t of the electronic expansion valve of the auxiliary loop is closed at low temperature by continuous temperature discharge_sovIf yes, the auxiliary circuit electronic expansion valve (61) executes a valve closing action to close the opening to 0 pps;

if the exhaust temperature of the compressor meets the condition: auxiliary circuit electronic expansion valve exhaust temperature T_d-close≤T_d< rate of change of intake and exhaust gas temperature control temperature T_d-onAt the moment, the electronic expansion valve of the auxiliary loop is controlled according to the sectional EVI superheat degree;

if the exhaust temperature of the compressor meets the condition: t is_dNot less than the temperature change rate control temperature T of the air inlet and exhaust_d-onAt the moment, the auxiliary loop electronic expansion valve (61) quits the EVI superheat degree control and controls according to the exhaust temperature change rate;

heating auxiliary circuit electronic expansion valve ring temperature T_aH-closeParameters set for the control program.

9. The air-supplying enthalpy-increasing control method for the ultralow-temperature air-cooling module machine, according to claim 8, is characterized in that: in step 312, under the heating mode, the sectional EVI superheat degree control method comprises the following steps:

if the exhaust temperature of the compressor meets the condition: auxiliary circuit electronic expansion valve exhaust temperature T_d-close≤T_dExhaust temperature T of electronic expansion valve with auxiliary circuit_d-openAt the moment, the auxiliary loop electronic expansion valve is overheated degree E according to heating target EVI_H-set0Carrying out PID control;

if the exhaust temperature of the compressor meets the condition: open auxiliary loop electronic expansion valve exhaust temperature T_d-open≤T_d< target compressor discharge temperature 1T_d-obj1At the moment, the auxiliary loop electronic expansion valve is overheated degree E according to heating target EVI_H-set1Carrying out PID control;

if the exhaust temperature of the compressor meets the condition: compressor target discharge temperature 1T_d-obj1≤T_d< target compressor discharge temperature 2T_d-obj2At the moment, the auxiliary loop electronic expansion valve is overheated degree E according to heating target EVI_H-set2Carrying out PID control;

if the exhaust temperature of the compressor meets the condition: compressor target discharge temperature 2T_d-obj2≤T_d< rate of change of intake and exhaust gas temperature control temperature T_d-onAt the moment, the auxiliary loop electronic expansion valve is overheated degree E according to heating target EVI_H-set3Carrying out PID control;

wherein the above EVI target superheat degree satisfies the condition: e_H-set0≥E_H-set1≥E_H-set2≥E_H-set3And the calculation mode of the actual superheat degree of the EVI is as follows:

EVI actual superheat degree E-EVI air supply temperature T_InjEVI Evaporation temperature T_Eva，

The exhaust temperature T of the electronic expansion valve of the auxiliary closing loop_d-closeOpen auxiliary loop electronic expansion valve exhaust temperature T_d-openTarget compressor discharge temperature 1T_d-obj1Target compressor discharge temperature 2T_d-obj2Intake/exhaust air temperature change rate control temperature T_d-onEVI heating target superheat degree E_H-set0EVI heating target superheat degree E_H-set1EVI heating targetDegree of superheat E_H-set2EVI heating target superheat degree E_H-set3All are parameters set by a control program;

the EVI air supply temperature T_InjThe EVI evaporation temperature T measured by a gas supply temperature sensor (63)_EvaMeasured by an evaporation temperature sensor (62).

10. The air-supplying enthalpy-increasing control method for the ultralow-temperature air-cooling module machine, according to claim 8, is characterized in that: in step S312, in the heating mode, the exhaust gas temperature change rate control method:

when exhaust temperature T_dThe change rate satisfies the condition:and then, calculating the opening degree change rate of the auxiliary loop electronic expansion valve according to the following formula:

when exhaust temperature T_dThe change rate satisfies the condition:and then, calculating the opening degree change rate of the auxiliary loop electronic expansion valve according to the following formula:

when in useWherein Δ U_max-openThe opening degree change rate of the auxiliary loop electronic expansion valve calculated in the (n +1) th sampling period at the time is the maximum valve opening step numberPerforming motion calculation;

when in useWherein Δ U_max-closeThe maximum valve closing step number is obtained, and the opening degree change rate of the auxiliary loop electronic expansion valve calculated in the (n +1) th sampling period at the moment is according toPerforming motion calculation;

the delta U_max-openAnd Delta U_max-closeThe opening and closing range of the valve body of the electronic expansion valve is set;

when the discharge temperature T of the compressor_dControlling temperature T from exceeding the rate of change of intake and exhaust temperatures_d-onThen, the temperature is reduced under the control action of the exhaust temperature change rate and is reduced to meet the conditions: t is_dControlling the temperature T at the temperature change rate of less than or equal to the exhaust gas temperature_d-offIf the auxiliary loop electronic expansion valve exits the exhaust gas temperature change rate control at the moment, the auxiliary loop electronic expansion valve enters the EVI superheat rate control, meanwhile, the exhaust gas temperature change rate sampling calculation is finished, and the exhaust gas temperature change rate control temperature T is_d-offThe conditions are satisfied: t is_d-obj1≤T_d-off≤T_d-obj2；

Wherein, T_aH-standCorrecting the reference environment temperature for the environment temperature of the opening degree change rate of the electronic expansion valve of the heating auxiliary loop, and setting parameters for a control program; t is_inH-standCorrecting the reference inlet water temperature for the inlet water temperature of the opening change rate of the electronic expansion valve of the heating auxiliary loop, and setting parameters for a control program; t is_d-offControlling the temperature for the rate of change of the exhaust gas temperature, a parameter set for the control program; k_H-addThe valve opening coefficient of the electronic expansion valve of the heating auxiliary loop is set as a parameter of a control program; k_H-sub: the valve closing coefficient of the electronic expansion valve of the heating auxiliary loop is a parameter set by a control program; alpha is alpha_H: a heating environment temperature index correction coefficient which is a parameter set by a control program; beta is a_H: the heating inlet water temperature index correction coefficient is a parameter set by a control program; when alpha is_HAnd beta_HAre respectively provided withWhen the value is 0, no correction is made for the ambient temperature and the inlet water temperature.

Technical Field

The invention belongs to the field of air conditioners, and particularly relates to an air supplementing and enthalpy increasing control system and method for an ultralow-temperature air-cooling modular machine.

Background

The ultralow-temperature air-cooled modular machine is applied to northern low-environment-temperature areas, and the control of air supply and enthalpy increase is vital to expanding the operation range of the press and reliably operating at low environmental temperature. The ultra-low temperature air-cooled modular machine which is currently applied to northern areas and used for heating in winter or supplying hot water generally adopts a quasi-two-stage compression compressor, and realizes intermediate pressure air supplement through an air supplement port arranged in the compressor.

The ultra-low temperature air cooling module machine adopts an air-supplying enthalpy-increasing compressor, reduces the exhaust temperature of the compressor on one hand, ensures the reliable operation of the compressor, increases the supercooling degree on the other hand, improves the enthalpy difference of inlet and outlet refrigerants in the evaporator, and increases the refrigerant quantity participating in circulation simultaneously so as to integrally improve the heat supply quantity of the unit. Therefore, in a refrigerant system of an ultra-low temperature unit, an auxiliary loop (air-supply enthalpy-increase loop) control method is crucial to reliable and stable operation of the ultra-low temperature unit and air supply quantity of a compressor, EVI superheat control (EVI superheat is EVI air-supply temperature-EVI evaporation temperature) is mostly adopted for controlling an EVI auxiliary loop (air-supply enthalpy-increase loop) in an ultra-low temperature air-cooling modular unit in the current market, and the T-T superheat control method cannot effectively reduce the exhaust temperature of the compressor under low-ring temperature and high water temperature, especially in the process of low-ring temperature and high-water temperature starting of a compressor, so that the compressor frequently jumps over-high exhaust temperature to protect the compressor, and the other control method is that different opening degrees of an electronic expansion valve of the EVI auxiliary loop are given by open-loop control according to different exhaust temperature ranges of the compressor, and the corresponding EVI auxiliary valve opening degrees under different exhaust temperatures are required to be set according to climates of different use places, the requirement on the experience is high, and exhaust temperature pre-judgment cannot be realized.

Disclosure of Invention

In view of the above, the present invention is directed to provide an air supplement and enthalpy increase control system and a control method for an ultra-low temperature air-cooled modular machine, wherein sectional EVI superheat degree control and exhaust temperature change rate control are combined to adapt to different use environments, the EVI superheat degree control is suitable for adjustment of a common high-temperature and low-temperature environment, and the exhaust temperature change rate control is suitable for an ultra-low temperature or ultra-high temperature environment and can be applied to more severe environments.

The auxiliary loop electronic expansion valve is used for controlling, and a mode of combining segmented superheat degree control and exhaust temperature change rate control is adopted, so that the method can be suitable for more environments with ultralow temperature and ultrahigh temperature.

In order to achieve the purpose, the technical scheme of the invention is realized as follows:

on one hand, the air-supplying and enthalpy-increasing control system of the ultralow-temperature air-cooling module machine comprises a main loop, an auxiliary loop and a four-way valve, wherein a first communication pipeline is arranged between a second port and a third port of the four-way valve, and an air-supplying and enthalpy-increasing compressor is arranged on the first communication pipeline;

one end of the main loop is communicated with a first four-way valve port, the other end of the main loop is communicated with a fourth four-way valve port, and the main loop is further sequentially communicated with a finned tube type heat exchanger, a first economizer chamber and a first heat exchange chamber of the heat exchanger;

the auxiliary loop comprises an auxiliary loop I and an auxiliary loop II, the economizer is further provided with a cavity II, one end of the auxiliary loop I is communicated with the input end of the cavity I of the economizer, the other end of the auxiliary loop I is communicated with the input end of the cavity II of the economizer, one end of the auxiliary loop II is communicated with the output end of the cavity II of the economizer, and the other end of the auxiliary loop II is communicated with the compressor; an auxiliary loop electronic expansion valve and an evaporation temperature sensor are arranged on the auxiliary loop I, and an air supply temperature sensor is arranged on the auxiliary loop II.

The heat exchanger is further provided with a heat exchange chamber II, the heat exchange chamber II is provided with a unit water outlet interface I and a unit water inlet interface II, the unit water outlet temperature sensor is arranged on the interface I, and the unit water inlet temperature sensor is arranged on the interface II;

the air inlet end of the air-supplying enthalpy-increasing compressor is provided with a compressor air suction temperature sensor, and the air outlet end of the air-supplying enthalpy-increasing compressor is provided with a compressor exhaust temperature sensor.

On the other hand, the application provides an air-supplying enthalpy-increasing control method for an ultralow-temperature air-cooling module machine, which comprises a refrigeration mode control method and a heating mode control method, wherein the refrigeration mode control method and the heating mode control method are controlled through the following steps:

s1: the unit completes initialization after being electrified, and the compressor is started and operates the stable operation time t of the compressor starting after receiving the starting command_startJudging whether the strip for opening the electronic expansion valve of the auxiliary loop is satisfiedA member;

s2: opening the auxiliary loop electronic expansion valve to the heating initial opening degree U under the condition of satisfying the condition of opening the auxiliary loop electronic expansion valve 61_OHOr initial opening degree U of refrigeration_OCAnd continuously assisting the heating initial opening maintaining time t of the loop electronic expansion valve_OHOr initial refrigeration on maintaining time t_OC；

S3: after the auxiliary loop electronic expansion valve meets the initial opening maintenance time, the environmental temperature T is carried out again_aAnd compressor discharge temperature T_dJudging and determining a control method;

s4: and starting segmented EVI superheat degree control or exhaust temperature change rate control.

Further, in step S2, in the cooling mode, the conditions for opening the auxiliary circuit electronic expansion valve are as follows: ambient temperature T_aRefrigeration open auxiliary loop electronic expansion valve ring temperature T is not more than_aC-openCompressor discharge temperature T_dExhaust temperature T of electronic expansion valve with auxiliary loop opened at least_d-open；

In the heating mode, the conditions for opening the electronic expansion valve of the auxiliary loop are as follows: ambient temperature T_aRing temperature T of electronic expansion valve of heating open auxiliary loop_aH-openCompressor discharge temperature T_dExhaust temperature T of electronic expansion valve with auxiliary loop opened at least_d-open；

The ambient temperature T_aMeasured by an ambient temperature sensor, the compressor discharge temperature T_dMeasured by a compressor discharge temperature sensor; ring temperature T of electronic expansion valve of refrigeration open auxiliary loop_aC-openOpen auxiliary loop electronic expansion valve exhaust temperature T_d-openHeating open auxiliary loop electronic expansion valve ring temperature T_aH-openAll are parameters set in the control program.

Further, in step S3, in the cooling mode, the control method selects the step of:

s301: firstly, the environmental temperature T is judged_a，

If the ambient temperature T_aThe conditions are satisfied: t is_aRing temperature T of electronic expansion valve for auxiliary circuit of refrigeration_aC-closeThe electronic expansion valve of the auxiliary loop executes the valve closing action and the auxiliary loopThe opening degree of the electronic expansion valve is closed to 0pps, wherein the ring temperature T of the electronic expansion valve of the auxiliary circuit of the refrigeration switch_aC-closeRing temperature T of electronic expansion valve for opening auxiliary circuit for refrigeration_aC-open；

If the ambient temperature T_aAnd (3) satisfying the following conditions: t is_aElectronic expansion valve ring temperature T of auxiliary circuit of refrigeration switch_aC-closeThen, the exhaust temperature T is performed again_dJudging;

s302: judging the exhaust temperature T_d，

If the compressor discharge temperature T_dThe conditions are satisfied: t is_dExhaust temperature T of electronic expansion valve of auxiliary circuit_d-closeAnd the delay t of the electronic expansion valve of the auxiliary loop is closed at low temperature by continuous temperature discharge_sovIf the opening degree of the auxiliary loop electronic expansion valve is not less than 0pps, the auxiliary loop electronic expansion valve executes a valve closing action;

if the exhaust temperature of the compressor meets the condition: auxiliary circuit electronic expansion valve exhaust temperature T_d-close≤T_d< rate of change of intake and exhaust gas temperature control temperature T_d-onAt the moment, the auxiliary loop electronic expansion valve controls the EVI superheat degree in a subsection mode according to a refrigeration mode control method;

if the exhaust temperature of the compressor meets the condition: t is_dNot less than the temperature change rate control temperature T of the air inlet and exhaust_d-onAt the moment, the auxiliary loop electronic expansion valve exits the EVI superheat degree control and controls the exhaust temperature change rate according to a refrigeration mode control method;

refrigeration auxiliary circuit electronic expansion valve ring temperature T_aC-closeElectronic expansion valve exhaust temperature T of auxiliary circuit_d-closeIntake/exhaust air temperature change rate control temperature T_d-onAll are parameters set in the control program.

Further, in the step 302, in the cooling mode, the segmented EVI superheat degree control method:

if the exhaust temperature of the compressor meets the condition: auxiliary circuit electronic expansion valve exhaust temperature T_d-close≤T_dExhaust temperature T of electronic expansion valve with auxiliary circuit_d-openAt the moment, the auxiliary loop electronic expansion valve refrigerates the target superheat degree E according to EVI_C-set0Carrying out PID control;

if the exhaust temperature of the compressor meets the condition: open auxiliary loop electronic expansion valve exhaust temperature T_d-open≤T_d< target compressor discharge temperature 1T_d-obj1At the moment, the auxiliary loop electronic expansion valve refrigerates the target superheat degree E according to EVI_C-set1Carrying out PID control;

if the exhaust temperature of the compressor meets the condition: compressor target discharge temperature 1T_d-obj1≤T_d< target compressor discharge temperature 2T_d-obj2At the moment, the auxiliary loop electronic expansion valve refrigerates the target superheat degree E according to EVI_C-set2Carrying out PID control;

if the exhaust temperature of the compressor meets the condition: compressor target discharge temperature of two T_d-obj2≤T_d< rate of change of intake and exhaust gas temperature control temperature T_d-onAt the moment, the auxiliary loop electronic expansion valve refrigerates the target superheat degree E according to EVI_C-set3Carrying out PID control;

wherein the above EVI target superheat degree satisfies the condition: e_C-set0≥E_C-set1≥E_C-set2≥E_C-set3And the calculation mode of the actual superheat degree of the EVI is as follows:

EVI actual superheat degree E-EVI air supply temperature T_InjEVI Evaporation temperature T_Eva，

The exhaust temperature T of the electronic expansion valve of the auxiliary closing loop_d-closeOpen auxiliary loop electronic expansion valve exhaust temperature T_d-openTarget compressor discharge temperature 1T_d-obj1Target compressor discharge temperature 2T_d-obj2Intake/exhaust air temperature change rate control temperature T_d-onAll the parameters are set by a control program, and the target superheat degree E of the EVI refrigeration is_C-set0(ii) a EVI refrigeration target superheat degree E_C-set1(ii) a EVI refrigeration target superheat degree E_C-set2(ii) a EVI refrigeration target superheat degree E_C-set3All are set parameters in a control program, and the EVI air supplement temperature T_InjMeasured by a gas supply temperature sensor, the EVI evaporation temperature T_EvaMeasured by an evaporation temperature sensor.

Further, in step S302, in the cooling mode, the exhaust gas temperature change rate control method includes:

when exhausting gasTemperature T_dThe change rate satisfies the condition:

and then, calculating the opening degree change rate of the auxiliary loop electronic expansion valve according to the following formula:

when exhaust temperature T_dThe change rate satisfies the condition:

and then, calculating the opening degree change rate of the auxiliary loop electronic expansion valve according to the following formula:

theta is the sampling period for calculating the exhaust gas temperature change rate when the compressor exhaust gas temperature T_dNot less than the temperature change rate control temperature T of the air inlet and exhaust_d-onThe exhaust temperature change rate is sampled at the beginning, and the exhaust temperature sampling calculation is carried out at intervals of theta, wherein T_d(n.theta) is the exhaust temperature value in the nth sampling period, T_d((n +1) · theta) is the exhaust temperature value in the (n +1) th sampling period;

the discharge temperature change rate calculated for the (n +1) th sampling period;

the opening change rate of the auxiliary loop electronic expansion valve calculated for the (n +1) th sampling period whenPerforming the action of opening the auxiliary circuit electronic expansion valve whenExecuting valve closing action, increasing the opening U (n & theta) of the electronic expansion valve of the previous auxiliary circuitOpening degree; when in useAnd keeping the current opening unchanged.

When in useWherein Δ U_max-openThe opening degree change rate of the auxiliary loop electronic expansion valve calculated in the (n +1) th sampling period at the time is the maximum valve opening step numberPerforming motion calculation;

when in useWherein Δ U_max-closeThe maximum valve closing step number is obtained, and the opening degree change rate of the auxiliary loop electronic expansion valve calculated in the (n +1) th sampling period at the moment is according toAnd performing motion calculation.

The delta U_max-openAnd Delta U_max-closeAre set according to the opening and closing range of the valve body of the electronic expansion valve.

When the discharge temperature T of the compressor_dControlling temperature T from exceeding the rate of change of intake and exhaust temperatures_d-onThen, the temperature is reduced under the control action of the exhaust temperature change rate and is reduced to meet the conditions: t is_dControlling the temperature T at the temperature change rate of less than or equal to the exhaust gas temperature_d-offAt this time, the auxiliary loop electronic expansion valve exits the exhaust gas temperature change rate control and enters the EVI superheat degree control, and the same is true for the auxiliary loop electronic expansion valveThe sampling calculation of the exhaust gas temperature change rate is finished, and the temperature T is controlled by the exhaust gas temperature change rate_d-offThe conditions are satisfied: t is_d-obj1≤T_d-off≤T_d-obj2。

T_aC-standCorrecting the reference environment temperature for the environment temperature of the opening degree change rate of the electronic expansion valve of the refrigeration auxiliary loop, and setting parameters for a control program; t is_inC-standCorrecting the reference inlet water temperature for the inlet water temperature of the opening change rate of the electronic expansion valve of the refrigeration auxiliary loop, and setting parameters for a control program; t is_d-offControlling the temperature for the rate of change of the exhaust gas temperature, a parameter set for the control program; k is a radical of_C-addThe valve opening coefficient of the electronic expansion valve of the refrigeration auxiliary loop is set as a parameter of a control program; k is a radical of_C-subThe valve closing coefficient of the electronic expansion valve of the refrigeration auxiliary loop, the parameter set for the control program and the parameter set for the control program; alpha is alpha_CThe parameter is set for the index correction coefficient of the refrigeration environment temperature and the control program; beta is a_CThe parameter is set for the index correction coefficient of the temperature of the cooling inlet water and the control program; if α is_CAnd beta_CWhen the values are all 0, the water inlet temperature and the environment temperature are not corrected.

Further, in step S3, in the heating mode, the control method selects the step of:

s311: firstly, the environmental temperature T is judged_a，

If the ambient temperature T_aThe conditions are satisfied: t is_aRing temperature T of electronic expansion valve for not less than heating auxiliary circuit_aH-closeIf the auxiliary loop electronic expansion valve executes the valve closing action, the opening degree of the auxiliary loop electronic expansion valve is closed to 0pps, wherein the ring temperature T of the auxiliary loop electronic expansion valve is heated and closed_aH-closeRing temperature T of electronic expansion valve for heating open auxiliary loop_aH-open；

If the ambient temperature T_aThe conditions are satisfied: t is_aElectronic expansion valve ring temperature T of auxiliary loop for heating_aH-closeThen, the exhaust temperature T is performed again_dJudging;

s312: judging the exhaust temperature T_d，

If the exhaust temperature of the compressor meets the condition: t is_d< turning off assistanceExhaust temperature T of loop electronic expansion valve_d-closeAnd the delay t of the electronic expansion valve of the auxiliary loop is closed at low temperature by continuous temperature discharge_sovIf the opening degree of the auxiliary loop electronic expansion valve is not less than 0pps, the auxiliary loop electronic expansion valve executes a valve closing action;

if the exhaust temperature of the compressor meets the condition: auxiliary circuit electronic expansion valve exhaust temperature T_d-close≤T_d< rate of change of intake and exhaust gas temperature control temperature T_d-onAt the moment, the electronic expansion valve of the auxiliary loop is controlled according to the sectional EVI superheat degree;

if the exhaust temperature of the compressor meets the condition: t is_dNot less than the temperature change rate control temperature T of the air inlet and exhaust_d-onAt the moment, the auxiliary loop electronic expansion valve exits the EVI superheat degree control and controls according to the exhaust temperature change rate;

heating auxiliary circuit electronic expansion valve ring temperature T_aH-closeParameters set for the control program.

Further, in step 312, in the heating mode, the segmented EVI superheat degree control method:

if the exhaust temperature of the compressor meets the condition: auxiliary circuit electronic expansion valve exhaust temperature T_d-close≤T_dExhaust temperature T of electronic expansion valve with auxiliary circuit_d-openAt the moment, the auxiliary loop electronic expansion valve is overheated degree E according to heating target EVI_H-set0Carrying out PID control;

if the exhaust temperature of the compressor meets the condition: open auxiliary loop electronic expansion valve exhaust temperature T_d-open≤T_d< target compressor discharge temperature 1T_d-obj1At the moment, the auxiliary loop electronic expansion valve is overheated degree E according to heating target EVI_H-set1Carrying out PID control;

if the exhaust temperature of the compressor meets the condition: compressor target discharge temperature 1T_d-obj1≤T_d< target compressor discharge temperature 2T_d-obj2At the moment, the auxiliary loop electronic expansion valve is overheated degree E according to heating target EVI_H-set2Carrying out PID control;

if the exhaust temperature of the compressor meets the condition: compressor target discharge temperature 2T_d-obj2≤T_d< rate of change of intake and exhaust gas temperature control temperature T_d-onAt the moment, the auxiliary loop electronic expansion valve is overheated degree E according to heating target EVI_H-set3Carrying out PID control;

wherein the above EVI target superheat degree satisfies the condition: e_H-set0≥E_H-set1≥E_H-set2≥E_H-set3And the calculation mode of the actual superheat degree of the EVI is as follows:

EVI actual superheat degree E-EVI air supply temperature T_InjEVI Evaporation temperature T_Eva，

The exhaust temperature T of the electronic expansion valve of the auxiliary closing loop_d-closeOpen auxiliary loop electronic expansion valve exhaust temperature T_d-openTarget compressor discharge temperature 1T_d-obj1Target compressor discharge temperature 2T_d-obj2Intake/exhaust air temperature change rate control temperature T_d-onEVI heating target superheat degree E_H-set0EVI heating target superheat degree E_H-set1EVI heating target superheat degree E_H-set2EVI heating target superheat degree E_H-set3All are parameters set by a control program;

the EVI air supply temperature T_InjEVI evaporation temperature T measured by air supply temperature sensor_EvaMeasured by an evaporation temperature sensor.

Further, in step S312, in the heating mode, the exhaust gas temperature change rate control method:

when exhaust temperature T_dThe change rate satisfies the condition:

and then, calculating the opening degree change rate of the auxiliary loop electronic expansion valve according to the following formula:

when exhaust temperature T_dThe change rate satisfies the condition:

and then, calculating the opening degree change rate of the auxiliary loop electronic expansion valve according to the following formula:

when in useWherein Δ U_max-openThe opening degree change rate of the auxiliary loop electronic expansion valve calculated in the (n +1) th sampling period at the time is the maximum valve opening step numberPerforming motion calculation;

when in useWherein Δ U_max-closeThe maximum valve closing step number is obtained, and the opening degree change rate of the auxiliary loop electronic expansion valve calculated in the (n +1) th sampling period at the moment is according toAnd performing motion calculation.

The delta U_max-openAnd Delta U_max-closeAre set according to the opening and closing range of the valve body of the electronic expansion valve.

When the discharge temperature T of the compressor_dControlling temperature T from exceeding the rate of change of intake and exhaust temperatures_d-onThen, the temperature is reduced under the control action of the exhaust temperature change rate and is reduced to meet the conditions: t is_dControlling the temperature T at the temperature change rate of less than or equal to the exhaust gas temperature_d-offIf the auxiliary loop electronic expansion valve exits the exhaust gas temperature change rate control at the moment, the auxiliary loop electronic expansion valve enters the EVI superheat rate control, meanwhile, the exhaust gas temperature change rate sampling calculation is finished, and the exhaust gas temperature change rate control temperature T is_d-offThe conditions are satisfied: t is_d-obj1≤T_d-off≤T_d-obj2。

Wherein, T_aH-standAuxiliary loop electronic expansion valve opening degree change rate environment for heatingCorrecting the reference environment temperature by temperature, and setting parameters for a control program; t is_inH-standCorrecting the reference inlet water temperature for the inlet water temperature of the opening change rate of the electronic expansion valve of the heating auxiliary loop, and setting parameters for a control program; t is_d-offControlling the temperature for the rate of change of the exhaust gas temperature, a parameter set for the control program; k_H-addThe valve opening coefficient of the electronic expansion valve of the heating auxiliary loop is set as a parameter of a control program; k_H-sub: the valve closing coefficient of the electronic expansion valve of the heating auxiliary loop is a parameter set by a control program; alpha is alpha_H: a heating environment temperature index correction coefficient which is a parameter set by a control program; beta is a_H: the heating inlet water temperature index correction coefficient is a parameter set by a control program; when alpha is_HAnd beta_HWhen the values are 0, no correction is made for the ambient temperature and the inlet water temperature.

Compared with the prior art, the air supplementing and enthalpy increasing control method of the ultralow-temperature air-cooling module machine has the following beneficial effects:

(1) the sectional EVI superheat degree control and the exhaust temperature change rate control are combined to adapt to different use environments, the EVI superheat degree control is suitable for adjustment of common high-temperature and low-temperature environments, and the exhaust temperature change rate control is suitable for ultra-low-temperature or ultra-high-temperature environments and can be applied to more severe environments.

(2) The exhaust temperature change rate control is combined with the environmental temperature, the exhaust temperature and the outlet water temperature to adjust the opening of the auxiliary loop electronic expansion valve so as to adapt to the ultra-low temperature or ultra-high temperature environment, and the auxiliary loop electronic expansion valve can be applied to more severe environments.

(3) The auxiliary loop electronic expansion valve opening degree change rate ensures reasonable air supplement amount, controls according to the exhaust temperature change rate, simultaneously takes the influence of the environment temperature and the outlet water temperature on the operation of the compressor into consideration, and has strong adaptability and stable operation.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate an embodiment of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:

fig. 1 is a schematic view of an air-supplying enthalpy-increasing control method of an ultra-low temperature air-cooling module machine according to an embodiment of the present invention.

Description of reference numerals:

1-a heat exchanger; 11-unit water outlet temperature sensor; 12-unit inlet water temperature sensor; 13-interface three; 14-interface four; 2-a four-way valve; 21-a first communication pipeline; 3-an economizer; 31-inlet one; 32-outlet one; 4-an enthalpy-increasing air compressor; 41-compressor suction temperature sensor; 42-compressor discharge temperature sensor; 5-a main loop; 51-an axial flow fan; 52-connecting a second pipeline; 53-connecting a third pipeline; 531-reservoir; 54-single valve one; 55-an input pipe; 551-a filter; 56-an output pipeline; 561-main loop electronic expansion valve; 57-connecting line four; 58-connecting pipeline five; 59-one-way valve two; 6-auxiliary loop piping; 61-auxiliary loop electronic expansion valve; 62-an evaporation temperature sensor; 63-air supply temperature sensor; 7-ambient temperature sensor; 8-a gas-liquid separator; 9-finned tube heat exchanger.

Detailed Description

It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like, indicate orientations or positional relationships based on those shown in the drawings, and are used only for convenience in describing the present invention and for simplicity in description, and do not indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and thus, are not to be construed as limiting the present invention. Furthermore, the terms "first", "second", etc. are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first," "second," etc. may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless otherwise specified.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art through specific situations.

The present invention will be described in detail below with reference to the embodiments with reference to the attached drawings.

As shown in fig. 1, the present application provides an air-supplying enthalpy-increasing control system for an ultra-low temperature air-cooling module machine, which includes a main loop 5, an auxiliary loop 6, and a four-way valve 2, wherein a first communication pipeline 21 is arranged between a second port and a third port of the four-way valve 2, and an air-supplying enthalpy-increasing compressor 4 is arranged on the first communication pipeline;

one end of a main loop 5 is communicated with a first four-way valve port, the other end of the main loop is communicated with a fourth four-way valve port, and the main loop is further sequentially communicated with a finned tube type heat exchanger 9, a first economizer 3 chamber and a first heat exchange chamber of a heat exchanger 1;

the auxiliary loop 6 comprises an auxiliary loop I and an auxiliary loop II, the economizer is also provided with a cavity II, one end of the auxiliary loop I is communicated with the input end of the cavity I of the economizer, the other end of the auxiliary loop I is communicated with the input end of the cavity II of the economizer 3, one end of the auxiliary loop II is communicated with the output end of the cavity II of the economizer 3, and the other end of the auxiliary loop II is communicated with the compressor 4; an auxiliary loop electronic expansion valve 61 and an evaporation temperature sensor 62 are arranged on the auxiliary loop I, and an air supply temperature sensor 63 is arranged on the auxiliary loop II.

The ultra-low temperature air cooling module machine adopts an air-supplying and enthalpy-increasing compressor, reduces the exhaust temperature of the compressor and the outlet temperature on one hand to ensure the reliable operation of the compressor, and increases the supercooling degree on the other hand to improve the enthalpy difference of the inlet and outlet refrigerants in the evaporator and increase the refrigerant quantity participating in circulation simultaneously so as to integrally improve the heat supply quantity of the unit. Therefore, in the refrigerant system of the ultra-low temperature unit, the auxiliary loop air-supplying and enthalpy-increasing loop control method is important for reliable and stable operation of the ultra-low temperature unit and air supply quantity of the compressor.

As shown in fig. 1, the heat exchanger comprises an ambient temperature sensor 7 for detecting an external temperature, and is further provided with a second heat exchange chamber, wherein the second heat exchange chamber is provided with a first unit water outlet interface and a second unit water inlet interface, the first interface is provided with a unit water outlet temperature sensor 11, and the second interface is provided with a unit water inlet temperature sensor 12;

the air inlet end of the air-supplying enthalpy-increasing compressor 4 is provided with a compressor air suction temperature sensor 41, and the air outlet end of the air-supplying enthalpy-increasing compressor 4 is provided with a compressor exhaust temperature sensor 42.

The finned tube type heat exchanger 9 is correspondingly provided with an axial flow fan 51, a cavity communicated with the main loop of the heat exchanger is provided with a third interface 13 and a fourth interface 14, the third interface 13 is communicated with a fourth port 14 of a four-way valve,

the economizer 3 comprises a first inlet 31 and a first outlet 32, an input pipeline 55 is communicated with the first inlet 31, a filter 551 is arranged on the input pipeline, a first three-way valve is arranged at the other end of the input pipeline 55, one port of the first three-way valve is connected with an axial flow fan 51 through a second connecting pipeline 52, the other port of the first three-way valve is communicated with a fourth port 14 through a third connecting pipeline 53, a liquid reservoir 531 is further arranged on the third connecting pipeline 53, a first single valve 54 is arranged at a position close to the first three-way valve on each of the second connecting pipeline 52 and the third connecting pipeline 53, and liquid in the first single valve flows into the input pipeline.

An outlet I32 of the economizer 3 is provided with an output pipeline 56, a main loop electronic expansion valve 561 is arranged on the output pipeline 56, a three-way valve II is arranged at the other end of the output pipeline, one end of the three-way valve II is connected with a connector IV 14 through a connecting pipeline IV 57, the other end of the three-way valve II is connected with the axial flow fan 51 through a connecting pipeline V58, single valves II 59 are arranged on the connecting pipeline IV 57 and the connecting pipeline V58, and the liquid in the single valves II 59 flows towards the direction far away from the output pipeline.

And the first connecting pipeline 21 is also connected with a gas-liquid separator 8 in series.

And the opening degree of the electronic expansion valve of the auxiliary loop can be in coordination with an environment temperature sensor, a compressor exhaust temperature sensor and a unit outlet water temperature sensor in the ultra-low temperature or ultra-high temperature environment.

As shown in fig. 1, on the other hand, the present application provides an air-supplying enthalpy-increasing control method for an ultra-low temperature air-cooling module machine, which includes a cooling mode control method and a heating mode control method, and both the cooling mode control method and the heating mode control method are controlled by the following steps:

s1: the unit completes initialization after being electrified, and the compressor is started and operates the stable operation time t of the compressor starting after receiving the starting command_startJudging whether the conditions for opening the auxiliary loop electronic expansion valve 61 are met;

s2: opening the auxiliary loop electronic expansion valve (61) to the heating initial opening degree U under the condition that the auxiliary loop electronic expansion valve (61) is opened_OHOr initial opening degree U of refrigeration_OCAnd continuously assisting the heating initial opening maintaining time t of the loop electronic expansion valve_OHOr initial refrigeration on maintaining time t_OC；

S3: after the auxiliary loop electronic expansion valve 61 meets the initial opening maintaining time, judging the environment temperature Ta and the compressor exhaust temperature Td again to determine a control method;

s4: and starting segmented EVI superheat degree control or exhaust temperature change rate control.

Compressor start-up stable running time t_startAuxiliary loop electronic expansion valve heating initial opening U_OHInitial opening degree U of refrigeration_OCAnd initial heating-up maintaining time t_OHInitial start maintenance time t of refrigeration_OCAll are control program setting parameters; the ambient temperature T_aMeasured by an ambient temperature sensor 7, the exhaust temperature T_dMeasured by a compressor discharge temperature sensor.

The sectional EVI superheat degree control and the exhaust temperature change rate control are combined to adapt to different use environments, and the exhaust temperature change rate control is combined with the environment temperature, the exhaust temperature and the outlet water temperature to adjust the opening degree of the auxiliary loop electronic expansion valve 61 to adapt to the ultra-low temperature or ultra-high temperature environment.

As shown in fig. 1, in step S2, the conditions for opening the auxiliary circuit electronic expansion valve 61 in the cooling mode are as follows: ambient temperature T_aRefrigeration open auxiliary loop electronic expansion valve ring temperature T is not more than_aC-openCompressor discharge temperature T_dExhaust temperature T of electronic expansion valve with auxiliary loop opened at least_d-open；

In the heating mode, the conditions for opening the auxiliary circuit electronic expansion valve 61 are: ambient temperature T_aRing temperature T of electronic expansion valve of heating open auxiliary loop_aH-openCompressor discharge temperature T_dExhaust temperature T of electronic expansion valve with auxiliary loop opened at least_d-open；

The ambient temperature T_aThe compressor discharge temperature T is measured by an ambient temperature sensor 7_dMeasured by a compressor discharge temperature sensor; ring temperature T of electronic expansion valve of refrigeration open auxiliary loop_aC-openOpen auxiliary loop electronic expansion valve exhaust temperature T_d-openHeating open auxiliary loop electronic expansion valve ring temperature T_aH-openAll are parameters set in the control program.

As shown in fig. 1, in step S3, in the cooling mode, the control method selects the steps of:

s301: firstly, the environmental temperature T is judged_a，

If the ambient temperature T_aThe conditions are satisfied: t is_aRing temperature T of electronic expansion valve for auxiliary circuit of refrigeration_aC-closeIf the temperature of the auxiliary loop electronic expansion valve is not lower than 0pps, the auxiliary loop electronic expansion valve 61 performs a valve closing action to close the auxiliary loop electronic expansion valve to 0pps, wherein the temperature T of the auxiliary loop electronic expansion valve is decreased_aC-closeRing temperature T of electronic expansion valve for opening auxiliary circuit for refrigeration_aC-open；

If the ambient temperature T_aAnd (3) satisfying the following conditions: t is_aElectronic expansion valve ring temperature T of auxiliary circuit of refrigeration switch_aC-closeThen, the exhaust temperature T is performed again_dJudging;

s302: judging the exhaust temperature T_d，

If the exhaust temperature of the compressor is highDegree T_dThe conditions are satisfied: t is_dExhaust temperature T of electronic expansion valve of auxiliary circuit_d-closeAnd the delay t of the electronic expansion valve of the auxiliary loop is closed at low temperature by continuous temperature discharge_sovIf so, the auxiliary circuit electronic expansion valve 61 executes a valve closing action to close the opening to 0 pps;

if the exhaust temperature of the compressor meets the condition: auxiliary circuit electronic expansion valve exhaust temperature T_d-close≤T_d< rate of change of intake and exhaust gas temperature control temperature T_d-onAt the moment, the auxiliary loop electronic expansion valve controls the EVI superheat degree in a subsection mode according to a refrigeration mode control method;

if the exhaust temperature of the compressor meets the condition: t is_dNot less than the temperature change rate control temperature T of the air inlet and exhaust_d-onAt this time, the auxiliary loop electronic expansion valve 61 exits the EVI superheat degree control and controls the exhaust temperature change rate according to the refrigeration mode control method;

refrigeration auxiliary circuit electronic expansion valve ring temperature T_aC-closeElectronic expansion valve exhaust temperature T of auxiliary circuit_d-closeIntake/exhaust air temperature change rate control temperature T_d-onAll are parameters set in the control program.

As shown in fig. 1, in the step 302, in the cooling mode, the segmented EVI superheat degree control method:

if the exhaust temperature of the compressor meets the condition: auxiliary circuit electronic expansion valve exhaust temperature T_d-close≤T_dExhaust temperature T of electronic expansion valve with auxiliary circuit_d-openAt the moment, the auxiliary loop electronic expansion valve refrigerates the target superheat degree E according to EVI_C-set0Carrying out PID control;

if the exhaust temperature of the compressor meets the condition: open auxiliary loop electronic expansion valve exhaust temperature T_d-open≤T_d< target compressor discharge temperature 1T_d-obj1At the moment, the auxiliary loop electronic expansion valve refrigerates the target superheat degree E according to EVI_C-set1Carrying out PID control;

if the exhaust temperature of the compressor meets the condition: compressor target discharge temperature 1T_d-obj1≤T_d< target compressor discharge temperature 2T_d-obj2At the moment, the auxiliary loop electronic expansion valve overheats according to the refrigeration target of EVIDegree E_C-set2Carrying out PID control;

if the exhaust temperature of the compressor meets the condition: compressor target discharge temperature 2T_d-obj2≤T_d< rate of change of intake and exhaust gas temperature control temperature T_d-onAt the moment, the auxiliary loop electronic expansion valve refrigerates the target superheat degree E according to EVI_C-set3Carrying out PID control;

wherein the above EVI target superheat degree satisfies the condition: e_C-set0≥E_C-set1≥E_C-set2≥E_C-set3And the calculation mode of the actual superheat degree of the EVI is as follows:

EVI actual superheat degree E-EVI air supply temperature T_InjEVI Evaporation temperature T_Eva，

The exhaust temperature T of the electronic expansion valve of the auxiliary closing loop_d-closeOpen auxiliary loop electronic expansion valve exhaust temperature T_d-openTarget compressor discharge temperature 1T_d-obj1Target compressor discharge temperature 2T_d-obj2Intake/exhaust air temperature change rate control temperature T_d-onAll the parameters are set by a control program, and the target superheat degree E of the EVI refrigeration is_C-set0(ii) a EVI refrigeration target superheat degree E_C-set1(ii) a EVI refrigeration target superheat degree E_C-set2(ii) a EVI refrigeration target superheat degree E_C-set3All are set parameters in a control program, and the EVI air supplement temperature T_InjEVI evaporation temperature T measured by air supply temperature sensor 63_EvaMeasured by the evaporation temperature sensor 62.

As shown in fig. 1, in the cooling mode, the exhaust gas temperature change rate control method in step S302:

when exhaust temperature T_dThe change rate satisfies the condition:

and then, calculating the opening degree change rate of the auxiliary loop electronic expansion valve according to the following formula:

when exhaust temperature T_dThe change rate satisfies the condition:

and then, calculating the opening degree change rate of the auxiliary loop electronic expansion valve according to the following formula:

theta is the sampling period for calculating the exhaust gas temperature change rate when the compressor exhaust gas temperature T_dNot less than the temperature change rate control temperature T of the air inlet and exhaust_d-onThe exhaust temperature change rate is sampled at the beginning, and the exhaust temperature sampling calculation is carried out at intervals of theta, wherein T_d(n.theta) is the exhaust temperature value in the nth sampling period, T_d((n +1) · theta) is the exhaust temperature value in the (n +1) th sampling period;

the discharge temperature change rate calculated for the (n +1) th sampling period;

the opening change rate of the auxiliary loop electronic expansion valve calculated for the (n +1) th sampling period whenPerforming the action of opening the auxiliary circuit electronic expansion valve whenThe valve closing operation is performed, and the opening U (n & theta) of the electronic expansion valve 61 of the auxiliary circuit is increased based on the previous opening U (n & theta)Opening degree; when in useAnd keeping the current opening unchanged.

When in useWherein Δ U_max-openThe opening degree change rate of the auxiliary loop electronic expansion valve calculated in the (n +1) th sampling period at the time is the maximum valve opening step numberPerforming motion calculation;

when in useWherein Δ U_max-closeThe maximum valve closing step number is obtained, and the opening degree change rate of the auxiliary loop electronic expansion valve calculated in the (n +1) th sampling period at the moment is according toAnd performing motion calculation.

The delta U_max-openAnd Delta U_max-closeAre set according to the opening and closing range of the valve body of the electronic expansion valve.

When the discharge temperature T of the compressor_dControlling temperature T from exceeding the rate of change of intake and exhaust temperatures_d-onThen, the temperature is reduced under the control action of the exhaust temperature change rate and is reduced to meet the conditions: t is_dControlling the temperature T at the temperature change rate of less than or equal to the exhaust gas temperature_d-offIf the auxiliary loop electronic expansion valve exits the exhaust gas temperature change rate control at the moment, the auxiliary loop electronic expansion valve enters the EVI superheat rate control, meanwhile, the exhaust gas temperature change rate sampling calculation is finished, and the exhaust gas temperature change rate control temperature T is_d-offThe conditions are satisfied: t is_d-obj1≤T_d-off≤T_d-obj2。

T_aC-standCorrecting the reference environment temperature for the environment temperature of the opening degree change rate of the electronic expansion valve of the refrigeration auxiliary loop, and setting parameters for a control program; t is_d-offControlling the temperature for the rate of change of the exhaust gas temperature, a parameter set for the control program; t is_inC-standOpening of electronic expansion valve for auxiliary circuit of refrigerationThe change rate inlet water temperature corrects the reference inlet water temperature and is a parameter set by a control program; k is a radical of_C-addThe valve opening coefficient of the electronic expansion valve of the refrigeration auxiliary loop is set as a parameter of a control program; k is a radical of_C-subThe valve closing coefficient of the electronic expansion valve of the refrigeration auxiliary loop, the parameter set for the control program and the parameter set for the control program; alpha is alpha_CThe parameter is set for the index correction coefficient of the refrigeration environment temperature and the control program; beta is a_CThe parameter is set for the index correction coefficient of the temperature of the cooling inlet water and the control program; if α is_CAnd beta_CWhen the values are all 0, the water inlet temperature and the environment temperature are not corrected.

If the unit is at the ambient temperature T in the running process_aFrom the satisfaction of the condition: t is_aRing temperature T of electronic expansion valve for auxiliary circuit of refrigeration_aC-closeGradually decrease to satisfy the condition: refrigeration opening auxiliary loop electronic expansion valve ring temperature T_aC-open＜T_aElectronic expansion valve ring temperature T of auxiliary circuit of refrigeration switch_aC-closeThen, the electronic expansion valve 61 of the auxiliary circuit of the EVI in this loop temperature interval is still not allowed to be opened until the ambient temperature is reduced to satisfy the condition: t is_aRefrigeration open auxiliary loop electronic expansion valve ring temperature T is not more than_aC-openAnd then judges whether to open the auxiliary circuit electronic expansion valve 61 according to the exhaust temperature.

The compressor is shut down due to reaching the set water temperature or due to a fault and the ambient temperature in the process always meets the conditions: refrigeration opening auxiliary loop electronic expansion valve ring temperature T_aC-open＜T_aElectronic expansion valve ring temperature T of auxiliary circuit of refrigeration switch_aC-closeWhen the water temperature rises or the fault is reset, the compressor is loaded and started again for a stable running time t_startThe electronic expansion valve 61 of the auxiliary circuit of EVI is processed according to the state before the compressor is stopped: if the electronic expansion valve 61 of the EVI auxiliary loop is opened before the shutdown, judging whether the electronic expansion valve 61 of the EVI auxiliary loop needs to be opened or not according to the exhaust temperature of the compressor during the reloading; if the temperature is within this ambient temperature before shutdown and the EVI auxiliary circuit electronic expansion valve 61 is not open, then the EVI auxiliary circuit electronic expansion valve 61 is not allowed to open when reloaded.

As shown in fig. 1, in the step S3, in the heating mode, the control method selects the step of:

s311: firstly, the environmental temperature T is judged_a，

If the ambient temperature T_aThe conditions are satisfied: t is_aRing temperature T of electronic expansion valve for not less than heating auxiliary circuit_aH-closeIf the auxiliary loop electronic expansion valve 61 performs a valve closing operation, the opening of the auxiliary loop electronic expansion valve is closed to 0pps, wherein the auxiliary loop electronic expansion valve is closed by heating and the loop temperature T is set_aH-closeRing temperature T of electronic expansion valve for heating open auxiliary loop_aH-open；

If the ambient temperature T_aThe conditions are satisfied: t is_aElectronic expansion valve ring temperature T of auxiliary loop for heating_aH-closeThen, the exhaust temperature T is performed again_dJudging;

s312: judging the exhaust temperature T_d，

If the exhaust temperature of the compressor meets the condition: t is_dExhaust temperature T of electronic expansion valve of auxiliary circuit_d-closeAnd the delay t of the electronic expansion valve of the auxiliary loop is closed at low temperature by continuous temperature discharge_sovIf so, the auxiliary circuit electronic expansion valve 61 executes a valve closing action to close the opening to 0 pps;

if the exhaust temperature of the compressor meets the condition: auxiliary circuit electronic expansion valve exhaust temperature T_d-close≤T_d< rate of change of intake and exhaust gas temperature control temperature T_d-onAt the moment, the electronic expansion valve of the auxiliary loop is controlled according to the sectional EVI superheat degree;

if the exhaust temperature of the compressor meets the condition: t is_dNot less than the temperature change rate control temperature T of the air inlet and exhaust_d-onAt this time, the auxiliary loop electronic expansion valve 61 exits the EVI superheat degree control and controls according to the exhaust temperature change rate;

heating auxiliary circuit electronic expansion valve ring temperature T_aH-closeParameters set for the control program.

As shown in fig. 1, in the step 312, in the heating mode, the segmented EVI superheat degree control method:

if the exhaust temperature of the compressor meets the condition: auxiliary circuit electronic expansion valve exhaust temperature T_d-close≤T_d< open auxiliary loop powerSub-expansion valve exhaust temperature T_d-openAt the moment, the auxiliary loop electronic expansion valve is overheated degree E according to heating target EVI_H-set0Carrying out PID control;

if the exhaust temperature of the compressor meets the condition: open auxiliary loop electronic expansion valve exhaust temperature T_d-open≤T_d< target compressor discharge temperature 1T_d-obj1At the moment, the auxiliary loop electronic expansion valve is overheated degree E according to heating target EVI_H-set1Carrying out PID control;

if the exhaust temperature of the compressor meets the condition: compressor target discharge temperature 1T_d-obj1≤T_d< target compressor discharge temperature 2T_d-obj2At the moment, the auxiliary loop electronic expansion valve is overheated degree E according to heating target EVI_H-set2Carrying out PID control;

if the exhaust temperature of the compressor meets the condition: compressor target discharge temperature 2T_d-obj2≤T_d< rate of change of intake and exhaust gas temperature control temperature T_d-onAt the moment, the auxiliary loop electronic expansion valve is overheated degree E according to heating target EVI_H-set3Carrying out PID control;

wherein the above EVI target superheat degree satisfies the condition: e_H-set0≥E_H-set1≥E_H-set2≥E_H-set3And the calculation mode of the actual superheat degree of the EVI is as follows:

EVI actual superheat degree E-EVI air supply temperature T_InjEVI Evaporation temperature T_Eva，

The exhaust temperature T of the electronic expansion valve of the auxiliary closing loop_d-closeOpen auxiliary loop electronic expansion valve exhaust temperature T_d-openTarget compressor discharge temperature 1T_d-obj1Target compressor discharge temperature 2T_d-obj2Intake/exhaust air temperature change rate control temperature T_d-onEVI heating target superheat degree E_H-set0EVI heating target superheat degree E_H-set1EVI heating target superheat degree E_H-set2EVI heating target superheat degree E_H-set3All are parameters set by a control program;

the EVI air supply temperature T_InjEVI evaporation temperature T measured by air supply temperature sensor 63_EvaMeasured by the evaporation temperature sensor 62.

As shown in fig. 1, in the heating mode, the exhaust gas temperature change rate control method in step S312:

when exhaust temperature T_dThe change rate satisfies the condition:

and then, calculating the opening degree change rate of the auxiliary loop electronic expansion valve according to the following formula:

when exhaust temperature T_dThe change rate satisfies the condition:

and then, calculating the opening degree change rate of the auxiliary loop electronic expansion valve according to the following formula:

when in useWherein Δ U_max-openThe opening degree change rate of the auxiliary loop electronic expansion valve calculated in the (n +1) th sampling period at the time is the maximum valve opening step numberPerforming motion calculation;

when in useWherein Δ U_max-closeThe maximum valve closing step number is obtained, and the opening degree change rate of the auxiliary loop electronic expansion valve calculated in the (n +1) th sampling period at the moment is according toAnd performing motion calculation.

The delta U_max-openAnd Delta U_max-closeAre set according to the opening and closing range of the valve body of the electronic expansion valve.

When the discharge temperature T of the compressor_dControlling temperature T from exceeding the rate of change of intake and exhaust temperatures_d-onThen, the temperature is reduced under the control action of the exhaust temperature change rate and is reduced to meet the conditions: t is_dControlling the temperature T at the temperature change rate of less than or equal to the exhaust gas temperature_d-offIf the auxiliary loop electronic expansion valve exits the exhaust gas temperature change rate control at the moment, the auxiliary loop electronic expansion valve enters the EVI superheat rate control, meanwhile, the exhaust gas temperature change rate sampling calculation is finished, and the exhaust gas temperature change rate control temperature T is_d-offThe conditions are satisfied: t is_d-obj1≤T_d-off≤T_d-obj2。

Wherein, T_aH-standCorrecting the reference environment temperature for the environment temperature of the opening degree change rate of the electronic expansion valve of the heating auxiliary loop, and setting parameters for a control program; t is_inH-standCorrecting the reference inlet water temperature for the inlet water temperature of the opening change rate of the electronic expansion valve of the heating auxiliary loop, and setting parameters for a control program; t is_d-offControlling the temperature for the rate of change of the exhaust gas temperature, a parameter set for the control program; k_H-addThe valve opening coefficient of the electronic expansion valve of the heating auxiliary loop is set as a parameter of a control program; k_H-sub: the valve closing coefficient of the electronic expansion valve of the heating auxiliary loop is a parameter set by a control program; alpha is alpha_H: a heating environment temperature index correction coefficient which is a parameter set by a control program; beta is a_H: the heating inlet water temperature index correction coefficient is a parameter set by a control program; when alpha is_HAnd beta_HWhen the values are 0, no correction is made for the ambient temperature and the inlet water temperature.

In a cold environment, whether the defrosting requirement is met or not is judged according to the defrosting condition in the unit heating operation process, the auxiliary loop electronic expansion valve 61 is not allowed to be opened in the defrosting process, if a certain system of the unit meets the defrosting condition, the EVI auxiliary loop electronic expansion valve executes valve closing action according to the excitation rate of the electronic expansion valve and is closed to 0 when the compressor in the corresponding system enters defrostingpps. When the system meets the condition of defrosting and the defrosting is exited, the stable operation time t of the compressor is reached after defrosting_dstThen according to the ambient temperature T again_aAnd compressor discharge temperature T_dAnd judging whether the electronic expansion valve 61 of the EVI auxiliary circuit needs to be opened or not.

If the unit is at the ambient temperature T in the running process_aFrom the satisfaction of the condition: t is_aRing temperature T of electronic expansion valve for not less than heating auxiliary circuit_aH-closeGradually decrease to satisfy the condition: heating open auxiliary loop electronic expansion valve ring temperature T_aH-open＜T_aElectronic expansion valve ring temperature T of auxiliary loop for heating_aH-closeThen, the electronic expansion valve 61 of the auxiliary circuit of the EVI in this loop temperature interval is still not allowed to be opened until the ambient temperature is reduced to satisfy the condition: t is_aRing temperature T of electronic expansion valve of heating open auxiliary loop_aH-openAnd then judges whether to open the auxiliary circuit electronic expansion valve 61 according to the exhaust temperature.

Due to the fact that the set water temperature is reached or the compressor is stopped due to a fault or the unit enters a defrosting mode and the ambient temperature always meets the conditions in the process: heating open auxiliary loop electronic expansion valve ring temperature T_aH-open＜T_aElectronic expansion valve ring temperature T of auxiliary loop for heating_aH-closeAnd when the compressor is loaded again and started after the water temperature is reduced or the fault is reset, the stable operation time t is passed_startOr the unit quits defrosting and the stable operation time t of the compressor is obtained after defrosting_dstAnd then, the electronic expansion valve 61 of the auxiliary circuit of the EVI is processed according to the state before the compressor is stopped or the state before defrosting: if the electronic expansion valve 61 of the EVI auxiliary loop is opened before the machine is stopped or before defrosting, judging whether the electronic expansion valve 61 of the EVI auxiliary loop needs to be opened according to the exhaust temperature of the compressor when the machine is loaded again; if the ambient temperature is present before shutdown or before defrosting and the EVI auxiliary circuit electronic expansion valve 61 is not open, then the EVI auxiliary circuit electronic expansion valve 61 is not allowed to open when reloading.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.