阅读说明：本技术 一种空气源热泵系统及空气源热泵的控制方法 (Air source heat pump system and control method of air source heat pump ) 是由 马超 钟文朝 张登科 陶骙 于 2021-09-08 设计创作，主要内容包括：本申请实施例提供一种空气源热泵系统及空气源热泵的控制方法,空气源热泵系统包括电控模块、热泵模块和旁通模块；热泵模块包括循环管路以及依次设置在循环管路上的压缩机、四通阀、第一换热器、冷媒散热装置、第一膨胀阀和第二换热器,第一换热器用于与水进行热交换,冷媒散热装置与电控模块热连接；旁通模块包括旁通管路和控制阀,旁通管路的第一端连接在第一换热器和冷媒散热装置之间的循环管路上,旁通管路的第二端连接在冷媒散热装置和第一膨胀阀之间的循环管路上,控制阀设置在旁通管路上,以在空气源热泵系统处于制热模式下,选择性地导通或截止旁通管路。本申请实施例的空气源热泵系统可以防止冷媒散热装置产生凝露。(The embodiment of the application provides an air source heat pump system and a control method of the air source heat pump, wherein the air source heat pump system comprises an electric control module, a heat pump module and a bypass module; the heat pump module comprises a circulating pipeline, and a compressor, a four-way valve, a first heat exchanger, a refrigerant heat dissipation device, a first expansion valve and a second heat exchanger which are sequentially arranged on the circulating pipeline, wherein the first heat exchanger is used for exchanging heat with water, and the refrigerant heat dissipation device is thermally connected with the electric control module; the bypass module comprises a bypass pipeline and a control valve, wherein the first end of the bypass pipeline is connected to the circulating pipeline between the first heat exchanger and the refrigerant heat dissipation device, the second end of the bypass pipeline is connected to the circulating pipeline between the refrigerant heat dissipation device and the first expansion valve, and the control valve is arranged on the bypass pipeline so as to selectively conduct or stop the bypass pipeline when the air source heat pump system is in a heating mode. The air source heat pump system can prevent the refrigerant heat dissipation device from generating condensation.)

1. An air-source heat pump system, comprising:

an electronic control module;

the heat pump module comprises a circulating pipeline, and a compressor, a four-way valve, a first heat exchanger, a refrigerant heat dissipation device, a first expansion valve and a second heat exchanger which are sequentially arranged on the circulating pipeline, wherein the first heat exchanger is used for exchanging heat with water, and the refrigerant heat dissipation device is thermally connected with the electronic control module;

the bypass module comprises a bypass pipeline and a control valve, a first end of the bypass pipeline is connected to the circulating pipeline between the first heat exchanger and the refrigerant heat dissipation device, a second end of the bypass pipeline is connected to the circulating pipeline between the refrigerant heat dissipation device and the first expansion valve, and the control valve is arranged on the bypass pipeline so as to selectively conduct or stop the bypass pipeline when the air source heat pump system is in a heating mode.

2. The air-source heat pump system according to claim 1, wherein the heat pump module further comprises a second expansion valve disposed on the circulation line between the refrigerant heat sink and the first end of the bypass line, and when the air-source heat pump system is in the heating mode, the second expansion valve is in a throttling state when the control valve is in a conducting state to conduct the bypass line.

3. The air-source heat pump system of claim 1 or 2, wherein the control valve is a one-way valve or a two-way valve.

4. A control method of an air source heat pump for the air source heat pump system of claim 1, the method comprising:

under the heating mode, acquiring the temperature of the outlet side of the refrigerant heat dissipation device;

and if the temperature of the outlet side is lower than the temperature of the outdoor environment, controlling the control valve to conduct the bypass pipeline.

5. The method of claim 4, wherein the heat pump module further comprises a second expansion valve disposed on the circulation line between the refrigerant heat sink and the first end of the bypass line, and wherein prior to controlling the control valve to direct the bypass line, the method further comprises:

controlling the number of steps of the second expansion valve to be opened to a maximum value.

6. The control method of claim 5, wherein after controlling the control valve to direct the bypass line, the method further comprises:

and adjusting the step number of the second expansion valve according to a preset rule.

7. The control method according to claim 6, wherein the adjusting the number of steps of the second expansion valve according to a preset rule includes:

calculating the adjustment step number of the second expansion valve according to a preset formula;

and adjusting the step number of the second expansion valve according to the calculated adjustment step number.

8. The control method according to claim 7,

the preset formula is as follows: Δ P ═ Tr-Ts) × F, where Δ P represents the number of adjustment steps, Tr represents the outlet-side temperature, Ts represents the outdoor ambient temperature, and F is an adjustment coefficient.

9. The control method according to claim 8, wherein the adjusting the number of steps of the second expansion valve based on the calculated adjustment number of steps comprises:

if the delta P is less than 0, the step number of the second expansion valve is adjusted to be smaller by delta P;

and if the delta P is larger than 0, increasing the step number of the second expansion valve by delta P steps.

10. The control method according to claim 7, wherein the adjusting the number of steps of the second expansion valve according to a preset rule further comprises:

the number of adjustment steps is calculated every G seconds.

11. The control method according to claim 5, wherein in a conducting state where the control valve is conducting the bypass line, if the outlet-side temperature satisfies a first preset condition, the control valve is controlled to stop the bypass line and control the number of steps of the second expansion valve to be opened to a maximum value; if the outlet side temperature does not meet a first preset condition and the duration that the outlet side temperature is lower than the outdoor environment temperature is longer than or equal to a first preset duration, controlling the compressor to stop;

the first preset condition is that the outlet side temperature is greater than or equal to the minimum value of a first set temperature and a second set temperature, and the second set temperature is the sum of the outdoor environment temperature and the first difference temperature.

12. The control method according to claim 11, wherein after the controlling the compressor to stop, the method further comprises:

if the outlet side temperature meets a second preset condition, controlling the compressor to start, controlling a control valve to stop a bypass pipeline and controlling the step number of a second expansion valve to be opened to the maximum value;

the second preset condition is that the outlet side temperature is greater than or equal to the sum of the outdoor environment temperature and the second return difference temperature, and the duration is greater than or equal to a second preset duration.

Technical Field

The application relates to the technical field of heat pumps, in particular to an air source heat pump system and a control method of the air source heat pump.

Background

At present, most of electric control modules of air source heat pumps adopt an air cooling mode for heat dissipation, and the trend of heat dissipation of the electric control modules by using a refrigerant heat dissipation device is already.

However, in the heating mode, if the temperature of the water flow exchanging heat with the refrigerant of the air source heat pump is too low, the temperature of the refrigerant flowing through the refrigerant heat dissipation device is too low, so that condensation is easily generated on the refrigerant heat dissipation device, and the existence of the condensation may cause the electric control module to generate electric leakage or short circuit, and the like, thereby causing the electric control module to fail.

Disclosure of Invention

In view of the above, embodiments of the present invention are intended to provide an air source heat pump system and a control method of the air source heat pump, which can prevent condensation from being generated in a refrigerant heat sink.

To achieve the above object, an embodiment of the present application provides an air-source heat pump system, including:

an electronic control module;

the heat pump module comprises a circulating pipeline, and a compressor, a four-way valve, a first heat exchanger, a refrigerant heat dissipation device, a first expansion valve and a second heat exchanger which are sequentially arranged on the circulating pipeline, wherein the first heat exchanger is used for exchanging heat with water, and the refrigerant heat dissipation device is thermally connected with the electronic control module;

the bypass module comprises a bypass pipeline and a control valve, a first end of the bypass pipeline is connected to the circulating pipeline between the first heat exchanger and the refrigerant heat dissipation device, a second end of the bypass pipeline is connected to the circulating pipeline between the refrigerant heat dissipation device and the first expansion valve, and the control valve is arranged on the bypass pipeline so as to selectively conduct or stop the bypass pipeline when the air source heat pump system is in a heating mode.

In one embodiment, the heat pump module further includes a second expansion valve, the second expansion valve is disposed on the circulation pipeline and between the refrigerant heat sink and the first end of the bypass pipeline, and when the air source heat pump system is in the heating mode, the second expansion valve is in a throttling state when the control valve is in a conduction state of conducting the bypass pipeline.

In one embodiment, the control valve is a one-way valve or a two-way valve.

Another embodiment of the present application provides a control method for an air source heat pump, which is used for the air source heat pump system, and the method includes:

under the heating mode, acquiring the temperature of the outlet side of the refrigerant heat dissipation device;

and if the temperature of the outlet side is lower than the temperature of the outdoor environment, controlling the control valve to conduct the bypass pipeline.

In one embodiment, the heat pump module further includes a second expansion valve disposed on the circulation line between the refrigerant heat sink and the first end of the bypass line, and before the control valve is controlled to open the bypass line, the method further includes:

controlling the number of steps of the second expansion valve to be opened to a maximum value.

In one embodiment, after controlling the control valve to open the bypass line, the method further comprises:

and adjusting the step number of the second expansion valve according to a preset rule.

In one embodiment, the adjusting the number of steps of the second expansion valve according to a preset rule includes:

calculating the adjustment step number of the second expansion valve according to a preset formula;

and adjusting the step number of the second expansion valve according to the calculated adjustment step number.

In one embodiment, the preset formula is: Δ P ═ Tr-Ts) × F, where Δ P represents the number of adjustment steps, Tr represents the outlet-side temperature, Ts represents the outdoor ambient temperature, and F is an adjustment coefficient.

In one embodiment, the adjusting the number of steps of the second expansion valve according to the calculated adjustment number of steps includes:

if the delta P is less than 0, the step number of the second expansion valve is adjusted to be smaller by delta P;

and if the delta P is larger than 0, increasing the step number of the second expansion valve by delta P steps.

In one embodiment, the adjusting the number of steps of the second expansion valve according to a preset rule further includes:

the number of adjustment steps is calculated every G seconds.

In one embodiment, when the control valve is in a conducting state where the bypass line is conducted, if the outlet-side temperature satisfies a first preset condition, the control valve is controlled to stop the bypass line and control the number of steps of the second expansion valve to be opened to a maximum value; if the outlet side temperature does not meet a first preset condition, and the duration of the outlet side temperature being lower than the outdoor environment temperature is longer than a first preset duration; or, if the duration that the outlet side temperature is lower than the outdoor environment temperature is equal to a first preset duration, controlling the compressor to stop;

the first preset condition is that the outlet side temperature is greater than or equal to the minimum value of a first set temperature and a second set temperature; or, the outlet side temperature is equal to the minimum value of a first set temperature and a second set temperature, and the second set temperature is the sum of the outdoor environment temperature and the first return temperature.

In one embodiment, after the controlling the compressor to stop, the method further comprises:

if the outlet side temperature meets a second preset condition, controlling the compressor to start, controlling a control valve to stop a bypass pipeline and controlling the step number of a second expansion valve to be opened to the maximum value;

the second preset condition is that the outlet side temperature is greater than or equal to the sum of the outdoor environment temperature and the second return difference temperature, and the duration is greater than or equal to a second preset duration.

The embodiment of the application provides an air source heat pump system and a control method of the air source heat pump, a bypass module with a bypass pipeline and a control valve is arranged in the air source heat pump system, under a heating mode, when the temperature of a refrigerant flowing through a refrigerant heat dissipation device is relatively low, the control valve can conduct the bypass pipeline, so that part of the refrigerant flows through the bypass pipeline, therefore, the flow of the refrigerant flowing through the refrigerant heat dissipation device can be reduced, the temperature of the refrigerant flowing through the refrigerant heat dissipation device is increased, the refrigerant heat dissipation device can be prevented from generating condensation, and the condition that an electric control module fails due to the existence of the condensation can be avoided.

Drawings

Fig. 1 is a schematic structural diagram of an air source heat pump system according to an embodiment of the present application, in which a half arrow indicates a flowing direction of a refrigerant in a heating mode;

fig. 2 is a schematic structural diagram of another air source heat pump system according to an embodiment of the present application, in which a half arrow indicates a flowing direction of a refrigerant in a heating mode;

fig. 3 is a front view of a mating relationship between the electronic control module and the refrigerant heat sink shown in fig. 1 and 2;

FIG. 4 is a left side view of FIG. 3;

fig. 5 is a schematic diagram illustrating a method for controlling an air source heat pump according to an embodiment of the present application;

fig. 6 is a flowchart of a control method of an air source heat pump according to an embodiment of the present application.

Description of the reference numerals

An electronic control module 10; a circuit board 11; an electronic component 12; a bracket 13; a heat pump module 20; a circulation line 21; a compressor 22; a four-way valve 23; a first heat exchanger 24; the first nozzle 24 a; the second water gap 24 b; a refrigerant heat sink 25; a heat dissipation plate 251; a fixed plate 252; a refrigerant line 253; an inlet end 253 a; an outlet end 253 b; a first expansion valve 26; a second heat exchanger 27; a second expansion valve 28; a bypass module 30; a bypass line 31; a control valve 32; a water tank 40; a water inlet 40 a; a water outlet 40 b; and a bulb 50.

Detailed Description

It should be noted that, in the present application, technical features in examples and embodiments may be combined with each other without conflict, and the detailed description in the specific embodiment should be understood as an explanation of the gist of the present application and should not be construed as an improper limitation to the present application.

An embodiment of the present application provides an air source heat pump system, please refer to fig. 1 and fig. 2, which includes an electronic control module 10, a heat pump module 20, and a bypass module 30; the heat pump module 20 comprises a circulation pipeline 21, and a compressor 22, a four-way valve 23, a first heat exchanger 24, a refrigerant heat dissipation device 25, a first expansion valve 26 and a second heat exchanger 27 which are sequentially arranged on the circulation pipeline 21, wherein the first heat exchanger 24 is used for exchanging heat with water, and the refrigerant heat dissipation device 25 is thermally connected with the electronic control module 10, that is, the refrigerant heat dissipation device 25 can realize heat dissipation of the electronic control module 10 by exchanging heat with the electronic control module 10; the bypass module 30 includes a bypass line 31 and a control valve 32, a first end of the bypass line 31 is connected to the circulation line 21 between the first heat exchanger 24 and the refrigerant heat sink 25, a second end of the bypass line 31 is connected to the circulation line 21 between the refrigerant heat sink 25 and the first expansion valve 26, and the control valve 32 is disposed on the bypass line 31 to selectively turn on or off the bypass line 31 when the air source heat pump system is in the heating mode.

Specifically, the air source heat pump system provided by the embodiment of the application can be used for devices such as floor heating devices and heat pump water heaters which need to use the air source heat pump system.

The refrigerant circulates in the circulation pipeline 21, and can exchange heat with water when flowing through the first heat exchanger 24, and can exchange heat with the electronic control module 10 when flowing through the refrigerant heat dissipation device 25.

The first heat exchanger 24 may be various heat exchangers having a heat exchanging function, for example, referring to fig. 1, the first heat exchanger 24 may be a water-refrigerant heat exchanger, and in the heating mode, water flows into the water-refrigerant heat exchanger from a first water gap 24a of the water-refrigerant heat exchanger, and flows out from a second water gap 24b after exchanging heat with a refrigerant flowing through the water-refrigerant heat exchanger in the water-refrigerant heat exchanger.

For example, referring to fig. 2, the first heat exchanger 24 may also be a heat exchange coil, and taking an air source heat pump system as an example of a heat pump water heater, water flows into the water tank 40 from the water inlet 40a of the water tank 40 and flows out from the water outlet 40b, and in the heating mode, water in the water tank 40 is heated into hot water after exchanging heat with a refrigerant flowing through the heat exchange coil.

The control valve 32 is used for controlling the on/off of the bypass line 31, and in the heating mode, when the control valve 32 turns on the bypass line 31, a part of the refrigerant flowing out of the first heat exchanger 24 flows to the first expansion valve 26 through the refrigerant heat dissipation device 25, and another part of the refrigerant flows to the first expansion valve 26 through the bypass line 31, which is equivalent to reducing the flow rate of the refrigerant flowing through the refrigerant heat dissipation device 25.

The control valve 32 shown in fig. 1 and 2 is a two-way valve for example, and in some embodiments, the control valve 32 may also be a one-way valve, and may also be other valves or valve sets having the function of turning on or off the bypass line 31.

Referring to fig. 4, the electronic control module 10 is mainly composed of a circuit board 11 and an electronic component 12, and pins of the electronic component 12 are soldered on the circuit board 11. To support the electronic component 12, for example, referring to fig. 4, a bracket 13 for supporting the electronic component 12 may be further disposed on the circuit board 11.

The air source heat pump system of the embodiment of the application is provided with the bypass module 30 with the bypass pipeline 31 and the control valve 32, in the heating mode, when the temperature of the refrigerant flowing through the refrigerant heat dissipation device 25 is relatively low, the control valve 32 can conduct the bypass pipeline 31, so that part of the refrigerant flows through the bypass pipeline 31, therefore, the refrigerant flow flowing through the refrigerant heat dissipation device 25 can be reduced, the temperature of the refrigerant flowing through the refrigerant heat dissipation device 25 is increased, the refrigerant heat dissipation device can be prevented from generating condensation, and the condition that the electric control module 10 fails due to the existence of the condensation can be avoided.

In an embodiment, referring to fig. 1 and fig. 2, the heat pump module 20 further includes a second expansion valve 28, the second expansion valve 28 is disposed on the circulation line 21 and located between the refrigerant heat dissipation device 25 and the first end of the bypass line 31, when the air source heat pump system is in the heating mode, when the control valve 32 is in the conduction state of conducting the bypass line 31, the second expansion valve 28 is in the throttling state, that is, when the bypass line 31 is in the conduction state, the second expansion valve 28 may be used to throttle the refrigerant flowing to the refrigerant heat dissipation device 25, and the refrigerant throttled by the second expansion valve 28 flows to the first expansion valve 26 through the bypass line 31, so that the flow rate of the refrigerant flowing through the refrigerant heat dissipation device 25 may be adjusted.

In addition, the air source heat pump system of the embodiment of the present application may further have a refrigeration mode, and in the refrigeration mode, the first heat exchanger 24 may cool or cool water by exchanging heat with water, that is, the air source heat pump system may also be used for a floor heating and ground cooling combined supply device or a heat pump water heater with a refrigeration function, and the second expansion valve 28 may also be used for throttling the refrigerant flowing out of the refrigerant heat sink 25 in the refrigeration mode. In addition, the second expansion valve 28 may also be used to throttle the refrigerant flowing out of the refrigerant heat sink 25 in the defrosting mode.

In an embodiment, referring to fig. 3 and 4, the cooling medium heat dissipation device 25 includes a heat dissipation plate 251, a fixing plate 252 and a cooling medium pipeline 253, the fixing plate 252 is disposed on the heat dissipation plate 251, a first mounting channel is defined between the fixing plate 252 and the heat dissipation plate 251, the heat dissipation plate 251 is thermally connected to the electronic control module 10, that is, the heat dissipation plate 251 can perform heat exchange with the electronic control module 10, a partial region of the cooling medium pipeline 253 is disposed in the first mounting channel, and two opposite ends of the cooling medium pipeline 253 along the extending direction extend out of the first mounting channel and are respectively communicated with the circulation pipeline 21.

Specifically, the fixing plate 252 and the heat dissipation plate 251 may be fastened and connected by a fastener such as a bolt or a screw, or may be fixedly connected by welding, or the fixing plate 252 and the heat dissipation plate 251 may be integrally formed.

For example, the first mounting passage may be formed on one of the fixing plate 252 and the heat dissipation plate 251, or grooves may be formed on the fixing plate 252 and the heat dissipation plate 251, and when the fixing plate 252 is disposed on the heat dissipation plate 251, the fixing plate 252 and the heat dissipation plate 251 together form the first mounting passage.

When the refrigerant circulating in the circulation pipeline 21 flows through the refrigerant heat dissipation device 25, the refrigerant flows into the refrigerant pipeline 253 from one end of the refrigerant pipeline 253 in the extension direction, and then flows out from the other end of the refrigerant pipeline 253 in the extension direction, and when the refrigerant flows through the region of the refrigerant pipeline 253 in the first mounting channel, the refrigerant can exchange heat with the heat dissipation plate 251, so that the heat dissipation effect on the electronic control module 10 can be achieved.

In one embodiment, the cooling medium heat dissipation device 25 further includes a first heat conductive material layer interposed between the electronic component 12 and the heat dissipation plate 251.

Specifically, the first heat conductive material layer is made of a material having a heat conductive function, such as a heat conductive silicone, and the first heat conductive material layer is sandwiched between the electronic component 12 and the heat dissipation plate 251, so that heat transfer resistance between the electronic component 12 and the heat dissipation plate 251 can be reduced, and a heat conductive effect between the electronic component 12 and the heat dissipation plate 251 can be improved.

In an embodiment, the cooling medium heat dissipation device 25 may also include a second heat conductive material layer, which is sandwiched between the heat dissipation plate 251 and the fixing plate 252.

Similar to the first heat conductive material layer, the second heat conductive material layer is also made of a material having a heat conductive function, such as heat conductive silicone, and the second heat conductive material layer is sandwiched between the heat dissipation plate 251 and the fixing plate 252, so that the heat transfer resistance between the heat dissipation plate 251 and the fixing plate 252 can be reduced, and the heat conductive effect between the heat dissipation plate 251 and the fixing plate 252 can be improved.

Another embodiment of the present application provides a control method of an air source heat pump, please refer to fig. 5, which mainly includes the following steps:

step S601, acquiring the temperature of the outlet side of the refrigerant heat dissipation device in the heating mode;

specifically, the outlet side temperature of the refrigerant heat sink 25 is mainly used for reflecting the temperature of the refrigerant after heat exchange with the electronic control module 10, for example, taking the refrigerant heat sink 25 shown in fig. 1 and fig. 2 as an example, in the heating mode, an end portion of the refrigerant pipeline 253 close to one end of the first heat exchanger 24 is an inlet end 253a, an end portion of the refrigerant pipeline 253 far from one end of the first heat exchanger 24 is an outlet end 253b, a temperature sensing bulb 50 may be disposed on the refrigerant pipeline 253 between the outlet end 253b and the first installation channel, and the pipe temperature of the refrigerant pipeline 253 here detected by the temperature sensing bulb 50 is the outlet side temperature.

In addition, in the heating mode, the first expansion valve 26 is in a throttle state.

And step S602, if the temperature of the outlet side is lower than the outdoor environment temperature, controlling the control valve to conduct the bypass pipeline.

Specifically, if the outlet side temperature is lower than the outdoor environment temperature, it indicates that the temperature of the refrigerant exchanging heat with the electronic control module 10 is relatively low, and condensation is easily generated on the refrigerant heat sink 25, so that a portion of the refrigerant can flow through the bypass line 31 by turning on the bypass line 31, so as to increase the temperature of the refrigerant flowing through the refrigerant heat sink 25 by reducing the flow rate of the refrigerant flowing through the refrigerant heat sink 25.

In an embodiment, for an air source heat pump system provided with a second expansion valve, before controlling the control valve to conduct the bypass line, the method further comprises: the number of steps of the second expansion valve is controlled to be opened to the maximum value. That is, in the heating mode, the second expansion valve 28 may be in the on and off state before the bypass line 31 is turned on, which corresponds to the case where the refrigerant flowing to the refrigerant heat sink 25 is not throttled before the bypass line 31 is turned on.

In one embodiment, after controlling the control valve to communicate the bypass line, the method further comprises: the number of steps of the second expansion valve is adjusted according to a predetermined rule, that is, the number of steps of the second expansion valve 28 is adjusted after the bypass line 31 is turned on, so that the second expansion valve 28 throttles the refrigerant flowing to the refrigerant heat sink 25.

In one embodiment, the adjusting the number of steps of the second expansion valve according to the preset rule comprises: calculating the adjustment step number of the second expansion valve according to a preset formula; the number of steps of the second expansion valve is adjusted according to the calculated adjustment number of steps, that is, the number of steps of the second expansion valve 28 that needs to be adjusted can be determined according to a set formula, so that the flow rate of the refrigerant flowing to the refrigerant heat sink 25 can be accurately controlled.

For example, the preset formula may be: Δ P ═ Tr-Ts) × F, where Δ P represents the number of adjustment steps, Tr represents the outlet-side temperature, Ts represents the outdoor ambient temperature, and F is the adjustment coefficient. That is, the number of adjustment steps is equal to the difference between the outlet side temperature and the outdoor ambient temperature multiplied by an adjustment coefficient, which is a parameter derived from the design, and may be, for example, greater than or equal to 1 and less than or equal to 10.

Taking the second expansion valve 28 with the maximum number of steps being 480 as an example, the adjustment range of the adjustment number of steps may be 0 to 480.

In the same air source heat pump system, the adjustment coefficient can be a fixed and unchangeable value, for example, F can be fixed as 2, the adjustment coefficient can also be changed according to a certain rule, for example, it can be set that F is 1 when the absolute value of the difference value between the outlet side temperature and the outdoor environment temperature is less than 2, namely | Tr-Ts | < 2, and F is 5 when the absolute value of the difference value between the outlet side temperature and the outdoor environment temperature is greater than 2 and less than 5, namely | Tr-Ts | < 5 > 2.

Note that, since the number of steps of the second expansion valve 28 is an integer, the calculation result of Δ P is also an integer.

Further, taking the preset formula as Δ P ═ Tr-Ts × F as an example, the step number of the second expansion valve is adjusted according to the calculated adjustment step number, which may be: if the delta P is less than 0, the step number of the second expansion valve is adjusted to be smaller by delta P; and if the delta P is larger than 0, increasing the step number of the second expansion valve by delta P steps. That is, when the difference between the outlet side temperature and the outdoor environment temperature is less than 0, it indicates that the current outlet side temperature is lower than the outdoor environment temperature, and the probability of condensation generated by the refrigerant heat dissipation device 25 is high, therefore, the step number of the second expansion valve 28 is adjusted to be smaller by Δ P steps, so as to reduce the refrigerant flow rate flowing through the refrigerant heat dissipation device 25, and when the difference between the outlet side temperature and the outdoor environment temperature is greater than 0, it indicates that the current outlet side temperature is higher than the outdoor environment temperature, and the probability of condensation generated by the refrigerant heat dissipation device 25 is low, therefore, the step number of the second expansion valve 28 is adjusted to be larger by Δ P steps, so as to increase the refrigerant flow rate flowing through the refrigerant heat dissipation device 25, so as to improve the heat dissipation effect of the refrigerant heat dissipation device 25 on the electronic control module 10.

It is understood that if Δ P is equal to 0, the number of steps of the second expansion valve is not adjusted.

In an embodiment, the adjusting the number of steps of the second expansion valve according to the preset rule further includes: the adjustment steps are calculated every G seconds, that is, the adjustment steps are calculated every a period of time, and the step of the second expansion valve 28 is adjusted accordingly according to the calculated result, so that the flow rate of the refrigerant flowing through the refrigerant heat sink 25 can be dynamically adjusted.

The interval time for calculating the adjustment step number may be determined as needed, and G may be greater than or equal to 10 and less than or equal to 200, for example.

In one embodiment, when the control valve is in a conducting state of conducting the bypass pipeline, if the outlet side temperature meets a first preset condition, the control valve is controlled to stop the bypass pipeline and control the step number of the second expansion valve to be opened to the maximum value. That is, when the outlet side temperature satisfies the first preset condition, it indicates that the temperature of the refrigerant flowing through the refrigerant heat sink 25 has risen to a temperature at which condensation does not occur on the refrigerant heat sink 25, and at this time, the bypass line 31 may be closed and the second expansion valve 28 may be switched to the on and unthrottled state.

For example, the first preset condition may be that the outlet side temperature is greater than the minimum value of a first set temperature and a second set temperature, wherein the first set temperature is a fixed value, the second set temperature is the sum of the outdoor environment temperature and the first return difference temperature, and the specific value of the first return difference temperature may be determined as required, for example, the first return difference temperature may be greater than 0 degrees and less than or equal to 20 degrees.

When a represents the first set temperature and B represents the first return temperature, the condition that the control valve 32 closes the bypass line 31 and controls the number of steps of the second expansion valve 28 to be maximum can be represented as: if Tr > min { a, Ts + B }, the control valve 32 is controlled to close the bypass line 31 and control the number of steps of the second expansion valve 28 to be opened to the maximum value. That is, if Tr is greater than the minimum value of a and Ts + B, it indicates that the temperature of the refrigerant flowing into the refrigerant heat sink 25 has increased to a temperature at which condensation does not occur on the refrigerant heat sink 25, and at this time, the bypass line 31 may be closed and the second expansion valve 28 may be switched to the on and unthrottled state.

In some embodiments, the first preset condition may be that the outlet side temperature is equal to the minimum value of the first set temperature and the second set temperature, which is equivalent to controlling the control valve 32 to close the bypass line 31 and controlling the number of steps of the second expansion valve 28 to be opened to the maximum value if Tr is min { a, Ts + B }.

In one embodiment, when the control valve is in the conducting state, if the outlet side temperature does not meet a first preset condition and the duration of the outlet side temperature being lower than the outdoor environment temperature is longer than a first preset duration, the compressor is controlled to stop.

The specific value of the first preset time period may be determined as needed, for example, the first preset time period may be greater than 0 minute and less than or equal to 20 minutes.

Where S1 represents the duration that the outlet side temperature is lower than the outdoor ambient temperature, and C represents the first preset duration, the above-described condition for controlling the shutdown of the compressor 22 can be represented as: in the on state of the control valve 32, if Tr does not satisfy the first preset condition and S1> C, the compressor 22 is controlled to be stopped. S1> C reflects that the outlet side temperature is always lower than the outdoor ambient temperature during the first preset time period, that is, the temperature of the refrigerant flowing through the refrigerant heat sink 25 is still relatively low when the bypass line 31 is turned on, and therefore, the flow of the refrigerant needs to be stopped by controlling the compressor 22 to be stopped.

In some embodiments, if the outlet-side temperature does not satisfy the first preset condition and the duration that the outlet-side temperature is lower than the outdoor ambient temperature is equal to the first preset duration, that is, S1 ═ C, the compressor may be controlled to stop when the control valve is in the on state.

In one embodiment, after controlling the compressor to shut down, the method further comprises: if the outlet side temperature meets the second preset condition, the compressor is controlled to start, the control valve is controlled to stop the bypass pipeline and control the step number of the second expansion valve to be opened to the maximum value, that is, when the outlet side temperature meets the second preset condition, the compressor 22 can be restarted, the bypass pipeline 31 is stopped, and the second expansion valve 28 is switched to a conducting and non-throttling state, so that the air source heat pump system can continuously work in the heating mode.

For example, the second preset condition may be that the outlet side temperature is greater than or equal to the sum of the outdoor environment temperature and the second return difference temperature, and the duration is greater than a second preset duration, where specific values of the second return difference temperature and the second preset duration may be determined as needed, for example, the second return difference temperature may be greater than 0 degrees and less than or equal to 20 degrees, and the second preset duration may be greater than or equal to 5 minutes and less than or equal to 60 minutes.

In addition, it should be noted that, in general, after the compressor 22 is stopped, the stop time of the compressor 22 needs to reach a certain time (generally, at least 3 minutes), and the compressor 22 can be restarted after the pressure difference of the compressor 22 meets the restart requirement, so that controlling the compressor 22 to start up as described in this application at least needs to ensure that the stop time of the compressor 22 can meet the restart requirement.

Where D represents the second return difference temperature, S2 represents the duration that the outlet-side temperature is greater than or equal to the sum of the outdoor ambient temperature and the second return difference temperature, and E represents the second preset duration, the above-mentioned condition for controlling the compressor 22 to start can be expressed as: if Tr is greater than or equal to Ts + D and S2> E, the compressor 22 is controlled to start. That is, if Tr is greater than or equal to Ts + D and S2 is greater than E, it indicates that the temperature of the refrigerant flowing into the refrigerant heat sink 25 has risen to a temperature at which condensation does not occur on the refrigerant heat sink 25, and at this time, the compressor 22 may be restarted.

In some embodiments, the second preset condition may also be that the outlet side temperature is greater than or equal to the sum of the outdoor ambient temperature and the second return difference temperature, and the duration is equal to a second preset duration, i.e., Tr ≧ Ts + D, and S2 ═ E.

In a specific embodiment, referring to fig. 6, the control method includes the following steps:

step S701, starting a heating mode;

step S702, controlling a control valve to stop the bypass pipeline and controlling the step number of the second expansion valve to be opened to the maximum value;

s703, acquiring the outlet side temperature Tr of the refrigerant heat dissipation device;

step S704, judging whether the outlet side temperature Tr is lower than the outdoor environment temperature Ts, if so, executing step S705, and if not, executing step S703;

step S705, controlling the control valve to conduct the bypass pipeline;

step S706, according to a preset formula: calculating Δ P every G seconds by (Tr-Ts) × F, and adjusting the number of steps of the second expansion valve according to the calculated Δ P;

step S707, judging whether the outlet side temperature Tr satisfies: tr > min { A, Ts + B }, if yes, executing step S702, and if no, executing step S708;

that is, it is determined whether the outlet-side temperature Tr is greater than the first set temperature a and the minimum value of the sum of the outdoor ambient temperature Ts and the first return temperature B.

Step S708, judging whether the duration S1 that the outlet side temperature Tr is lower than the outdoor environment temperature Ts is greater than a first preset duration C, if so, executing step S710, and if not, executing step S705;

step S709, controlling the compressor to stop;

step S710, judging whether the following conditions are met: tr is more than or equal to Ts + D, and S2 is more than E, if yes, step S711 is executed, and if no, step S709 is executed;

that is, it is determined whether the duration S2 in which the outlet-side temperature Tr is greater than or equal to the sum of the outdoor ambient temperature Ts and the second return temperature D is greater than the second preset duration E.

And step S711, controlling the compressor to start, controlling the control valve to stop the bypass pipeline and controlling the step number of the second expansion valve to be opened to the maximum value.

The various embodiments/implementations provided herein may be combined with each other without contradiction. The above description is only a preferred embodiment of the present application and is not intended to limit the present application, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application are included in the protection scope of the present application.