阅读说明：本技术 一种空调室外机 (Outdoor unit of air conditioner ) 是由 任艳君 丛辉 朱海涛 王锡元 于 2020-12-22 设计创作，主要内容包括：本发明公开一种空调室外机,包括压缩机、蒸发器、冷凝器、经济器、位于冷凝器与经济器之间的第一节流装置、位于经济器与蒸发器之间的第二节流装置；运行阶段分为始动阶段、通常运转阶段、停止阶段；始动阶段为压缩机启动至加载稳定的过程；停止阶段为控制停机开始至压缩机完全停止的过程；通常运转阶段位于始动阶段与停止阶段之间的运转过程；在始动阶段、通常运转阶段分别对第二节流装置进行固定开度控制。本发明在第二节流装置无频繁开关的前提下保证经济器内的压力在适宜的范围内,延长第二节流装置的寿命,提高空调室外机电控系统及制冷系统的稳定性；另外,第二节流装置无需频繁开关控制提高了空调室外机的控制效率、控制稳定性及可靠性。(The invention discloses an air conditioner outdoor unit, which comprises a compressor, an evaporator, a condenser, an economizer, a first throttling device positioned between the condenser and the economizer, and a second throttling device positioned between the economizer and the evaporator, wherein the first throttling device is connected with the economizer; the operation stage comprises a starting stage, a normal operation stage and a stopping stage; the starting stage is a process from starting of the compressor to stable loading; the stopping stage is a process from the start of stop control to the complete stop of the compressor; the normal operation stage is an operation process between the start stage and the stop stage; the second throttle device is controlled to have a fixed opening degree in each of the start-up stage and the normal operation stage. The invention ensures that the pressure in the economizer is in a proper range on the premise that the second throttling device is not frequently opened and closed, prolongs the service life of the second throttling device and improves the stability of an electric control system and a refrigerating system of the outdoor unit of the air conditioner; in addition, the second throttling device does not need to be frequently switched on and off, so that the control efficiency, the control stability and the reliability of the air conditioner outdoor unit are improved.)

1. An outdoor unit of an air conditioner, comprising a compressor, an evaporator, a condenser, an economizer, a first throttling device between the condenser and the economizer, a second throttling device between the economizer and the evaporator; it is characterized in that the preparation method is characterized in that,

the operation stage comprises a starting stage, a normal operation stage and a stopping stage;

the starting stage is a process from the starting of the compressor to the loading to the stabilization;

the stopping stage is a process from the beginning of shutdown control to the complete stop of the compressor;

the normal operation stage is an operation process between the starting stage and the stopping stage; the second throttle device is controlled to have a fixed opening degree in each of the start-up phase and the normal operation phase.

2. The outdoor unit of claim 1, wherein the fixed opening degrees comprise a first fixed opening degree and a second fixed opening degree;

in the starting stage, the opening degree of the second throttling device is controlled to be the first fixed opening degree;

in the normal operation stage, the opening degree of the second throttle device is controlled to the second fixed opening degree.

3. The outdoor unit of claim 2, further comprising a suction pressure sensor installed at a suction port of the compressor, for detecting a suction pressure of the compressor;

setting an early warning value of low suction pressure; in the starting stage, judging the suction pressure; and if the suction pressure is lower than the suction pressure low warning value, controlling to enter the normal operation stage, and controlling the opening degree of the second throttling device to be the second fixed opening degree.

4. The outdoor unit of claim 3, further comprising an economizer pressure sensor provided in the economizer for detecting an economizer pressure;

setting a low pressure value and a high pressure value of the economizer; judging the economizer pressure in the normal operation stage; if the economizer pressure exceeds the economizer high pressure value for a first time period, controlling the second throttling device to increase the opening degree;

and when the economizer pressure lasts for a fifth time length between the economizer low pressure value and the economizer high pressure value and no early warning exists or the second throttling device is opened to the maximum opening degree of the second throttling device, maintaining the current opening degree.

5. The outdoor unit of claim 4, further comprising a discharge pressure sensor and a discharge temperature sensor respectively disposed at a discharge port of the compressor for detecting a discharge pressure and a discharge temperature;

setting an exhaust pressure high warning value and an exhaust superheat degree low warning value; in the normal operation stage, the economizer pressure, the intake pressure, the exhaust pressure, and the exhaust superheat are determined; if the economizer pressure lasts for a second time length between the economizer low pressure value and the economizer high pressure value, the suction pressure is lower than the suction pressure low warning value or the exhaust pressure is higher than the exhaust pressure high warning value, and the exhaust superheat degree is not lower than the exhaust superheat degree low warning value, controlling the second throttling device to increase the opening degree;

and when the economizer pressure lasts for a fifth time between the economizer low-pressure value and the economizer high-pressure value and no early warning exists or the second throttling device is opened to the maximum opening degree, maintaining the current opening degree.

6. The outdoor unit of claim 5, wherein the economizer pressure is determined during the normal operation phase; controlling the second throttling device to reduce the opening degree if the economizer pressure is lower than the economizer low pressure value for a third time period;

and when the economizer pressure lasts for a fifth time period between the economizer low pressure value and the economizer high pressure value and no early warning exists or the second throttling device is closed to the minimum opening degree of the second throttling device, maintaining the current opening degree.

7. The outdoor unit of claim 6, wherein the economizer pressure, the discharge pressure, the suction pressure, and the discharge superheat are determined in the normal operation phase;

controlling the second throttling device to reduce the opening degree if the economizer pressure lasts for a fourth time between the economizer low pressure value and the economizer high pressure value and the exhaust superheat degree is lower than the exhaust superheat degree low warning value, no high warning of the exhaust pressure exists and no low warning of the suction pressure exists;

and when the economizer pressure lasts for a fifth time period between the economizer low pressure value and the economizer high pressure value and no early warning exists or the second throttling device is closed to the minimum opening degree, maintaining the current opening degree.

8. The outdoor unit of claim 7, wherein in the normal operation stage, it is determined whether or not to control the shutdown; if the compressor is stopped, judging whether the compressor is stopped; controlling the second throttle to be closed to the minimum opening degree if the compressor is stopped;

and if the compressor is stopped without control and the compressor is not stopped, controlling to judge the pressure of the economizer.

9. The outdoor unit of any one of claims 1 to 8, wherein the first throttling means comprises a first electric control valve, a first orifice plate; the two ends of the first electric throttle valve after being connected with the first orifice plate in series are respectively connected with the condenser and the economizer;

the second throttling device comprises a second electric regulating valve and a second orifice plate; and the two ends of the second electric regulating valve after being connected with the first pore plate in series are respectively connected with the economizer and the evaporator.

10. The outdoor unit of claim 9, wherein the first and second electrically controlled adjusting valves are electric ball valves or electric butterfly valves.

Technical Field

The invention relates to the technical field of air conditioning, in particular to an air conditioner outdoor unit.

Background

The air conditioner outdoor unit system provided with the economizer comprises a compressor, an evaporator, a condenser, the economizer, a first throttling device and a second throttling device, wherein the first throttling device is positioned between the condenser and the economizer, and the second throttling device is positioned between the economizer and the evaporator. For a magnetic suspension refrigerating unit, a reasonable throttling device and a control scheme thereof are key factors for ensuring the efficient and fault-free operation of the refrigerating unit. For a magnetic suspension refrigerating unit provided with a flash tank type economizer, the liquid level control of the economizer is also particularly important, when the liquid level of the economizer is too high, air is supplied and liquid is carried, the damage of a compressor is caused, the liquid level of an evaporator is too low, and the unit fault is caused by too low suction pressure. When the liquid level of the economizer is too low, the medium pressure of the economizer can not form a better liquid seal, so that the gas leakage of a refrigerating system is caused, and the medium pressure gas supplement can not play a due role.

The throttling device commonly used in the magnetic suspension centrifuge group industry at present is an electronic expansion valve. A liquid level sensor is arranged on the economizer or the evaporator, and the opening degree of the electronic expansion valve is controlled by setting a target liquid level through the liquid level sensor. However, the flash tank type economizer has large liquid level fluctuation, frequent opening and closing of the expansion valve can be caused by adopting a liquid level sensor to control the opening of the electronic expansion valve, the fluctuation of the current of the unit and the instability of the unit system can be caused, and the service life of the electronic expansion valve can be shortened.

Disclosure of Invention

In order to solve the problems of instability of the unit and short service life of the electronic expansion valve caused by frequent opening and closing of the electronic expansion valve in the prior art, the invention provides the outdoor unit of the air conditioner, which adopts a fixed opening control scheme to improve the running stability of the unit and prolong the service life of a throttling device.

In order to achieve the purpose, the invention adopts the following technical scheme:

the invention provides an air conditioner outdoor unit, which comprises a compressor, an evaporator, a condenser, an economizer, a first throttling device positioned between the condenser and the economizer, and a second throttling device positioned between the economizer and the evaporator, wherein the first throttling device is connected with the economizer;

the operation stage comprises a starting stage, a normal operation stage and a stopping stage;

the starting stage is a process from the starting of the compressor to the loading to the stabilization;

the stopping stage is a process from the beginning of shutdown control to the complete stop of the compressor;

the normal operation stage is an operation process between the starting stage and the stopping stage; the second throttle device is controlled to have a fixed opening degree in each of the start-up phase and the normal operation phase.

In one embodiment, the fixed opening degree comprises a first fixed opening degree and a second fixed opening degree;

in the starting stage, the opening degree of the second throttling device is controlled to be the first fixed opening degree;

in the normal operation stage, the opening degree of the second throttle device is controlled to the second fixed opening degree.

In one embodiment, the system further comprises a suction pressure sensor, which is arranged at a suction port 11 of the compressor and is used for detecting the suction pressure of the compressor;

setting an early warning value of low suction pressure; in the starting stage, judging the suction pressure; and if the suction pressure is lower than the suction pressure low warning value, controlling to enter the normal operation stage, and controlling the opening degree of the second throttling device to be the second fixed opening degree.

In one embodiment, the economizer further comprises an economizer pressure sensor disposed within the economizer for detecting the economizer pressure;

setting a low pressure value and a high pressure value of the economizer; judging the economizer pressure in the normal operation stage; if the economizer pressure exceeds the economizer high pressure value for a first time period, controlling the second throttling device to increase the opening degree;

and when the economizer pressure lasts for a fifth time length between the economizer low pressure value and the economizer high pressure value and no early warning exists or the second throttling device is opened to the maximum opening degree of the second throttling device, maintaining the current opening degree.

In one embodiment, the system further comprises a discharge pressure sensor and a discharge temperature sensor which are respectively arranged at the discharge port of the compressor and used for detecting the discharge pressure and the discharge temperature;

setting an exhaust pressure high warning value and an exhaust superheat degree low warning value; in the normal operation stage, the economizer pressure, the intake pressure, the exhaust pressure, and the exhaust superheat are determined; if the economizer pressure lasts for a second time length between the economizer low pressure value and the economizer high pressure value, the suction pressure is lower than the suction pressure low warning value or the exhaust pressure is higher than the exhaust pressure high warning value, and the exhaust superheat degree is not lower than the exhaust superheat degree low warning value, controlling the second throttling device to increase the opening degree;

and when the economizer pressure lasts for a fifth time between the economizer low-pressure value and the economizer high-pressure value and no early warning exists or the second throttling device is opened to the maximum opening degree, maintaining the current opening degree.

In one embodiment, during the normal operation phase, the economizer pressure is determined; controlling the second throttling device to reduce the opening degree if the economizer pressure is lower than the economizer low pressure value for a third time period;

and when the economizer pressure lasts for a fifth time period between the economizer low pressure value and the economizer high pressure value and no early warning exists or the second throttling device is closed to the minimum opening degree of the second throttling device, maintaining the current opening degree.

In one embodiment, in the normal operation stage, the economizer pressure, the exhaust pressure, the intake pressure, and the exhaust superheat are determined;

controlling the second throttling device to reduce the opening degree if the economizer pressure lasts for a fourth time between the economizer low pressure value and the economizer high pressure value and the exhaust superheat degree is lower than the exhaust superheat degree low warning value, no high warning of the exhaust pressure exists and no low warning of the suction pressure exists;

and when the economizer pressure lasts for a fifth time period between the economizer low pressure value and the economizer high pressure value and no early warning exists or the second throttling device is closed to the minimum opening degree, maintaining the current opening degree.

In one embodiment, in the normal operation stage, whether to control shutdown is judged; if the compressor is stopped, judging whether the compressor is stopped; controlling the second throttle to be closed to the minimum opening degree if the compressor is stopped;

and if the compressor is stopped without control and the compressor is not stopped, controlling to judge the pressure of the economizer.

In some embodiments, the first flow restriction device comprises a first electrically actuated regulator valve, a first orifice plate; the two ends of the first electric throttle valve after being connected with the first orifice plate in series are respectively connected with the condenser and the economizer;

the second throttling device comprises a second electric regulating valve and a second orifice plate; and the two ends of the second electric regulating valve after being connected with the first pore plate in series are respectively connected with the economizer and the evaporator.

In some embodiments, the first and second electrically-operated regulating valves are electric ball valves or electric butterfly valves.

Compared with the prior art, the technical scheme of the invention has the following technical effects:

the air conditioner outdoor unit controls the fixed opening degree of the second throttling device, so that the pressure in the economizer is maintained in a proper pressure range, and the second throttling device is not frequently switched on or switched off; firstly, the second throttling device is not frequently switched on and switched off, so that the service life of the second throttling device is prolonged, the maintenance cost is reduced, and the user experience is improved; secondly, the second throttling device can keep the current level of an electric control system of the air conditioner outdoor unit stable without frequent switching, so that the running stability of the air conditioner outdoor unit is improved; finally, the control efficiency of the air conditioner outdoor unit is improved through the frequent switching control of the second throttling device, and the control stability and reliability are improved.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a schematic view of a refrigeration system of an outdoor unit of an air conditioner according to the present invention;

FIG. 2 is a flow chart of an air conditioner outdoor unit control according to the present invention;

FIG. 3 is a schematic structural diagram of a first throttling device and a second throttling device;

FIG. 4 is a schematic view of a multi-well plate configuration;

FIG. 5 is a schematic diagram of a single-hole plate.

Reference numerals:

1. a compressor; 2. a condenser; 3. an evaporator; 4. an economizer; 5. a first throttling device; 6. a second throttling device; 7. an air supply pipeline; 8. an orifice plate; 9. a flange; 10. sealing gaskets; 11. an air suction port; 12. an exhaust port; 51. a first electric control valve; 52. a first orifice plate; 61. a second electric control valve; 62. A second orifice plate; 81. a cylindrical bore; 82. a conical bore;

EEV1, first fixed opening;

EEV2, second fixed opening;

EEV, second throttle opening;

EEVmin, minimum opening;

EEVmax, maximum opening;

pd, exhaust pressure;

pe, economizer pressure;

PL, economizer Low pressure value;

ph, economizer high pressure value;

t1, a first duration;

t2, a second duration;

t3, third duration;

t4, fourth duration;

t5, fifth duration.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it is to be understood that the terms "center", "upper", "lower", "front", "rear", "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 only for convenience of description and simplicity of 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.

In the description of the present invention, it should be noted that the terms "mounted," "connected," and "connected" are to be construed broadly and may be, for example, fixedly connected, detachably connected, or integrally connected unless otherwise explicitly stated or limited. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art. In the foregoing description of embodiments, the particular features, structures, materials, or characteristics may be combined in any suitable manner in any one or more embodiments or examples.

The terms "first", "second" and "first" 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" or "second" 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 an embodiment, referring to fig. 1 and 2, the outdoor unit of an air conditioner of the present embodiment includes a compressor 1, a condenser 2, an evaporator 3, an economizer 4, a first throttling device 5 between the condenser 2 and the economizer 4, and a second throttling device 6 between the economizer 4 and the evaporator 3.

The compressor 1 is a magnetic suspension two-stage centrifugal compressor and comprises an air suction port 11 and an air exhaust port 12; the exhaust port 12 is connected with the condenser 2; the air suction port 11 is connected with the evaporator 3; the economizer 4 is a flash tank type economizer; the condenser 2 is connected with the economizer 4 through a first throttling device 5; the economizer 4 is connected to the evaporator 3 via a second throttle device 6.

The low-temperature and low-pressure gaseous refrigerant evaporated by the evaporator 3 enters the compressor 1 through the air suction port 11; the compressor 1 adjusts the flow rate of the refrigerant entering the suction port 11 of the compressor 1 by adjusting the frequency and the opening degree of the inlet guide vane. The low-temperature low-pressure gaseous refrigerant enters the compressor 1, is compressed by the first-stage impeller, is mixed with the medium-temperature medium-pressure saturated gas from the economizer 4, and is continuously compressed by the second-stage impeller to form the high-temperature high-pressure gaseous refrigerant; the high-temperature and high-pressure gas refrigerant then enters the condenser 2, and is cooled by cooling water in the condenser 2 to change into a high-temperature and high-pressure liquid refrigerant.

The high-temperature high-pressure liquid refrigerant is depressurized by a first throttling device 5 and then enters an economizer 4, and is separated into a medium-temperature medium-pressure saturated liquid refrigerant and a flash gaseous refrigerant in the economizer 4; the medium-pressure gaseous refrigerant enters the secondary impeller of the compressor through the air supplement pipeline 7 and is continuously compressed by the secondary impeller of the compressor; the medium-pressure saturated liquid refrigerant is depressurized by the second throttling device 6 and then enters the evaporator 3 to become a low-temperature and low-pressure liquid refrigerant, thereby forming a main cycle.

In the embodiment, the medium-pressure saturated liquid refrigerant is reasonably controlled through the second throttling device 6, so that the economizer 4 and the evaporator 3 are kept at reasonable liquid levels under various working conditions, and the stable operation of the unit is ensured.

The operation stage of the air conditioner outdoor unit comprises a starting stage, a normal operation stage and a stopping stage; the starting stage is the process from the start of the compressor 1 to the stable loading; the stopping stage is a process from the start of stop control to the complete stop of the compressor 1; the normal operation phase is an operation process between the end of the start phase and the beginning of the stop phase; the second throttle device 6 is controlled to have a fixed opening degree in each of the start-up stage and the normal operation stage.

The fixed opening degrees comprise a first fixed opening degree and a second fixed opening degree EEV 2; in the start phase, the opening degree of the second throttle device 6 is controlled to the first fixed opening degree EEV 1; in the normal operation stage, the opening degree of the second throttle device 6 is controlled to the second fixed opening degree EEV 2.

In this embodiment, the second throttling device 6 in the start stage and the normal operation stage is controlled to operate at a fixed opening, so that the pressure and the liquid level in the economizer 4 and the evaporator 3 are basically kept in a normal range, and the second throttling device 6 is not frequently opened or closed, thereby improving the stability of an electric control system of the outdoor unit of the air conditioner and the stability of a refrigeration system, and prolonging the service life of the second throttling device 6. In addition, since the second throttling device 6 is not frequently controlled to be opened and closed, the control efficiency of the air conditioner outdoor unit is improved, and the stability and the reliability of the control of the air conditioner outdoor unit are improved.

In addition, the materials of the evaporator liquid level sensor and the economizer liquid level sensor are saved by controlling the fixed opening, and the cost of the whole machine is reduced.

In an embodiment, referring to fig. 1 and 2, the outdoor unit of the air conditioner of the present embodiment further includes a suction pressure sensor disposed at the suction port 11 for detecting a suction pressure of the compressor 1.

And setting an early warning value of low suction pressure. In the initial stage, the suction pressure and whether the compressor 1 is loaded to be stable (loading is finished) are judged; if the loading of the compressor 1 is completed, the control enters a normal operation stage, the opening degree of the second throttle device 6 is controlled to be the second fixed opening degree EEV2, and the second fixed opening degree EEV2 is kept to operate; if the loading of the compressor 1 is not completed, the judgment of whether the loading of the compressor 1 is completed is continued.

If the suction pressure is lower than the suction pressure low warning value in the starting stage, the control enters a normal operation stage, and the opening of the second throttling device 6 is controlled to be a second fixed opening EEV 2; and if the suction pressure has no low value early warning, judging whether the loading of the compressor 1 is finished.

The embodiment adjusts the second throttling device 6 when the fluctuation working condition of the low value early warning of the suction pressure appears in the starting stage, prevents the liquid levels of the economizer 4 and the evaporator 3 from fluctuating to cause unstable operation of the unit, ensures that the economizer 4 and the evaporator 3 operate in a proper pressure range and the liquid levels are stable when the starting stage is controlled by a fixed opening degree, and improves the stability of the operation of the air conditioner outdoor unit system.

In one embodiment, referring to fig. 1 and 2, the outdoor unit of the air conditioner further includes an economizer pressure sensor disposed in the economizer 4 for detecting an economizer pressure Pe.

Setting a low-pressure value PL and a high-pressure value Ph of the economizer; in the normal operation stage, judging the economizer pressure Pe; if the economizer pressure Pe exceeds the economizer high pressure Ph for a first time period T1, the second throttle device 6 is controlled to increase the opening degree.

In controlling the second throttle apparatus 6 to increase the opening degree, when the economizer pressure Pe continues for a fifth period T5 between the economizer low pressure value PL and the economizer high pressure value Ph without warning or when the opening degree of the second throttle apparatus 6 is opened to the maximum opening degree EEVmax of the second throttle apparatus 6, the current opening degree operation is maintained.

The embodiment adjusts the opening degree of the second throttling device 6 according to the changing working condition that the pressure Pe of the economizer exceeds the high-pressure value Ph of the economizer in the normal operation stage, ensures that the economizer 4 and the evaporator 3 operate in the proper pressure range and have stable liquid level when the fixed opening degree is controlled in the starting stage, and improves the stability of the operation of the air conditioner outdoor unit system.

In this embodiment, the outdoor unit of the air conditioner further includes a discharge pressure sensor disposed at the discharge port 12 of the compressor 1 for detecting the discharge pressure Pd. The economizer high pressure value Ph and the economizer low pressure value PL are calculated according to the following formulas.

1) When the operating pressure ratio Pr is less than or equal to 1.9,

economizer low pressure PL =0.98 Pd/((Pr/1.11) ^0.5)

Economizer high pressure Ph =1.07 x Pd/((Pr/1.11) ^0.5)

2) When the operating pressure ratio Pr is more than or equal to 1.93,

economizer low pressure PL = (Pd/((Pr/1.2) ^0.5)

Economizer high pressure Ph =1.025 (Pd/((Pr/1.2) ^0.5)

Pr: the operation pressure ratio, the ratio of the exhaust pressure Pd to the suction pressure Ps;

pd: the exhaust pressure;

pe: economizer pressure;

PL: the low pressure value of the economizer;

ph: the high pressure value of the economizer.

The above pressure values are absolute pressures.

In one embodiment, referring to fig. 1 and 2, the outdoor unit of the air conditioner further includes a discharge temperature sensor disposed at the discharge port 12 of the compressor 1 for detecting a discharge temperature.

The exhaust superheat degree is a difference between the exhaust temperature and the saturation temperature at the exhaust pressure Pd, and can be calculated from the exhaust temperature and the exhaust pressure Pd.

Setting an exhaust pressure high warning value and an exhaust superheat degree low warning value; in the normal operation stage, judging the economizer pressure Pe, the suction pressure, the exhaust pressure Pd and the exhaust superheat degree; and if the economizer pressure Pe is between the economizer low pressure value PL and the economizer high pressure value Ph for a second time period T2, the suction pressure is lower than the suction pressure low warning value or the exhaust pressure Pd is higher than the exhaust pressure high warning value, and the exhaust superheat degree is not lower than the exhaust superheat degree low warning value, controlling the second throttling device 6 to increase the opening degree.

In controlling the second throttle device 6 to increase the opening degree, if the economizer pressure Pe continues for a fifth period T5 between the economizer low pressure value PL and the economizer high pressure value Ph without warning or when the second throttle device 6 is opened to the maximum opening degree EEVmax, the current opening degree operation is maintained.

The embodiment adjusts the opening degree of the second throttling device 6 according to the variation working condition of low early warning of suction pressure or high early warning of exhaust pressure in the normal operation stage, ensures that the economizer 4 and the evaporator 3 operate in the appropriate pressure range and have stable liquid level when the fixed opening degree is controlled in the normal operation stage, and improves the stability of the operation of the air conditioner outdoor unit system.

In one embodiment, referring to fig. 1 and 2, in the normal operation stage, the economizer pressure Pe is determined; the second throttle device 6 is controlled to decrease the opening degree if the economizer pressure Pe is lower than the economizer low pressure value PL for a third period T3.

In the process of controlling the second throttle apparatus 6 to decrease the opening degree, if the economizer pressure Pe continues for a fifth period T5 between the economizer low pressure value PL and the economizer high pressure value Ph and there is no warning or the opening degree of the second throttle apparatus 6 is closed to the minimum opening degree EEVmin of the second throttle apparatus 6, the current opening degree operation is maintained.

The embodiment adjusts the opening degree of the second throttling device 6 according to the variation working condition that the pressure Pe of the economizer is lower than the low pressure value PL of the economizer in the normal operation stage, ensures that the economizer 4 and the evaporator 3 operate in the appropriate pressure range and the liquid level is stable when the fixed opening degree is controlled in the normal operation stage, and improves the stability of the operation of the air conditioner outdoor unit system.

In one embodiment, referring to fig. 1 and 2, in the normal operation stage, the economizer pressure Pe, the exhaust pressure Pd, the intake pressure, and the exhaust superheat are determined.

And if the economizer pressure Pe continues for a fourth time period T4 between the economizer low pressure value PL and the economizer high pressure value Ph, and the exhaust superheat degree is lower than the exhaust superheat degree low warning value, the high warning of the exhaust pressure Pd is not performed, and the low warning of the suction pressure is performed, controlling the second throttling device 6 to reduce the opening degree.

In the process of controlling the second throttle apparatus 6 to reduce the opening degree, if the economizer pressure Pe continues for a fifth period T5 between the economizer low pressure value PL and the economizer high pressure value Ph and when there is no warning or the opening degree of the second throttle apparatus 6 is closed to the minimum opening degree EEVmin, the current opening degree operation is maintained.

The embodiment adjusts the opening degree of the second throttling device 6 according to the changing working condition that the exhaust superheat degree is lower than the low early warning value of the exhaust superheat degree in the normal operation stage, ensures that the economizer 4 and the evaporator 3 operate in the appropriate pressure range and have stable liquid level during the control of the fixed opening degree in the normal operation stage, and improves the stability of the operation of the air conditioner outdoor unit system.

Preferably, the first time length T1, the second time length T2, the third time length T3, the fourth time length T4 and the fifth time length T5 are within the same interval range and are all 3 s-10 s.

Further preferably, the first time period T1, the second time period T2, the third time period T3, the fourth time period T4 and the fifth time period T5 are all 5 s.

In an embodiment, referring to fig. 1 and 2, in the normal operation stage, whether to control the shutdown is determined; if the machine is stopped, judging whether the compressor 1 stops; if the compressor 1 is stopped, the opening degree of the second throttle device 6 is controlled to be closed to the minimum opening degree EEVmin.

If the machine is stopped without control and the compressor 1 is not stopped, the suction pressure, the exhaust pressure Pd, the economizer pressure Pe and the exhaust superheat degree are controlled to be judged, and the opening degree of the second throttling device 6 is adjusted according to the judgment result.

The embodiment ensures that the pressure and the liquid level in the evaporator 3 and the economizer are stable in the stopping stage, and improves the running stability of the outdoor unit of the air conditioner.

In some embodiments, with reference to fig. 1 and 3, the first throttling device 5 comprises a first electric regulating valve 51, a first orifice 52; the condenser 2 and the economizer 4 are respectively connected with two ends of the first electric throttle valve after being connected with the first orifice plate 52 in series.

The second throttling device 6 comprises a second electric regulating valve 61 and a second orifice plate 62; the economizer 4 and the evaporator 3 are connected to both ends of the second electric control valve 61 connected in series with the first orifice plate 52.

Preferably, the first electric control valve 51 and the second electric control valve 61 are electric ball valves or electric butterfly valves.

In this embodiment, the first throttling device 5 and the second throttling device 6 are in the form of electric control valves connected with orifice plates in series. The electric regulating valve can adopt an electric ball valve or an electric butterfly valve or other types of electric regulating valves.

The valve body runner of the electric ball valve is a V-shaped port ball valve, the adjusting performance is equal percentage type, the interface type is flange connection, and the flange and the ball valve are sealed by a sealing gasket, so that the electric ball valve is convenient to disassemble, assemble and maintain and has good adjusting performance.

Referring to fig. 3, 4 and 5, the orifice plate 8 may be a fixed single orifice plate or a fixed multi-orifice plate; the hole of the orifice plate 8 is formed by a cylindrical hole 81 and a conical hole 82 with a small end diameter equal to the diameter of the cylindrical hole 81 and connected with one end of the cylindrical hole 81; the pore plate 8 is in a flange butt-clamp type, a sealing gasket 10 is used for sealing between the flange 9 and the pore plate 8, and the installation direction of the pore plate 8 is that the refrigerant flows from the cylindrical hole 81 to the tapered hole 82.

The selection of the opening sectional area of the pore plate 8 is crucial, if the opening sectional area is too small, the liquid supply amount of the evaporator 3 is insufficient under the working condition of small pressure ratio, and the fault shutdown caused by low suction pressure is easy to cause; if the sectional area of the opening is too large, the electric throttling valve is excessively closed, so that the liquid level fluctuation is large or the air is sucked to carry liquid, and the unit cannot stably operate. The size of the opening sectional area in the scheme is calculated according to the maximum required refrigerating capacity under the minimum pressure ratio of the actual operation of the magnetic suspension refrigerating unit, the opening sectional area under the working condition is relatively large and is the maximum working condition of the actual operation of the unit, and the adjustment of the series electric ball valve can be applied to all working conditions under the condition.

For a refrigerating unit configured with the flash tank type economizer, the electric regulating valve is connected with the orifice plate in series to replace a plurality of electronic expansion valves connected in parallel, and no matter whether the refrigerating unit is large-capacity or small-capacity, the capacity requirement can be met by connecting one electric regulating valve with one orifice plate in series.

In the foregoing description of embodiments, the particular features, structures, materials, or characteristics may be combined in any suitable manner in any one or more embodiments or examples.

The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.