CN114353378B - Heat pump unit control method, control device and heat pump unit - Google Patents

Abstract

The invention discloses a heat pump unit control method, a control device and a heat pump unit, wherein the method comprises the following steps: the unit operates to acquire the air suction superheat degree, the economizer parameter and the exhaust parameter; judging whether the suction superheat degree reaches an initial target suction superheat degree or not; when the suction superheat degree does not reach the initial target suction superheat degree, executing a first control process: adjusting the opening of the main electronic expansion valve according to the suction superheat degree and the initial target suction superheat degree; and when the suction superheat degree reaches the initial target suction superheat degree, executing a second control process: and adjusting the opening degree of the main electronic expansion valve and the opening degree of the auxiliary electronic expansion valve based on the economizer parameter and the exhaust parameter. By adopting the invention, the optimal control of the refrigerant flow in different flow paths of the heat pump unit and the optimal regulation and control of the unit efficiency can be realized.

Description

Heat pump unit control method, control device and heat pump unit

technical field

The invention belongs to the technical field of heat pump systems, and in particular relates to a heat pump unit control method, a control device and a heat pump unit.

Background technique

As a widely used unit equipment at present, the heat pump unit uses a refrigerant circulation system composed of a compressor, a condenser, an electronic expansion valve, an economizer and an evaporator to realize the heat pump function.

The electronic expansion valve in the refrigerant cycle system of the existing heat pump unit usually includes a main electronic expansion valve arranged in the main circuit of the refrigerant cycle and an auxiliary electronic expansion valve arranged in the auxiliary gas supply circuit where the economizer is located. The opening control adjusts the refrigerant flow of the main road and the auxiliary road to meet the performance requirements of the heat pump unit operation.

In the prior art, most of the heat pump units adopt a mode in which the main electronic expansion valve and the auxiliary electronic expansion valve are separately controlled. The expansion valves are controlled independently of each other. When the opening of the expansion valve in the main road is too small, the channel flow rate in the auxiliary road will increase when the opening of the expansion valve remains unchanged, and there is a risk of liquid return from the compressor through the auxiliary road; when the opening of the expansion valve in the main road is too large When the opening of the auxiliary expansion valve is too large, the flow rate of the auxiliary channel will decrease when the opening of the expansion valve is constant, and there will be problems such as insufficient air supply of the compressor and a decrease in energy efficiency; moreover, the opening of the auxiliary expansion valve will also affect the exhaust temperature of the unit, which will easily lead to The unit cannot run stably. Therefore, the existing method of independent control of the expansion valves cannot obtain optimal control of the refrigerant flow in the main circuit and the auxiliary circuit, and it is difficult to achieve an optimized state of unit efficiency.

Contents of the invention

The object of the present invention is to provide a heat pump unit control method and control device, which can realize the optimal control of the refrigerant flow rate in different flow paths of the heat pump unit and the optimal regulation and control of the unit efficiency.

In order to achieve the purpose of the above invention, the control method of the heat pump unit provided by the present invention is realized by the following technical solutions:

A control method for a heat pump unit, the heat pump unit includes a main electronic expansion valve arranged in a refrigerant cycle main circuit and an auxiliary electronic expansion valve arranged in an auxiliary gas supplementary circuit where an economizer is located, the method comprising:

The unit is running, and the suction superheat, economizer parameters and exhaust parameters are obtained;

judging whether the suction superheat reaches an initial target suction superheat;

When the suction superheat degree does not reach the initial target suction superheat degree, execute the first control process: adjust the opening of the main electronic expansion valve according to the suction superheat degree and the initial target suction superheat degree Spend;

When the suction superheat reaches the initial target suction superheat, execute the second control process: adjust the opening degree of the main electronic expansion valve and the auxiliary valve based on the economizer parameter and the exhaust parameter. Electronic expansion valve opening;

The economizer parameter is economizer superheat or economizer subcooling; the exhaust parameter is exhaust superheat or exhaust temperature.

In one of the preferred embodiments, adjusting the opening degree of the main electronic expansion valve and the opening degree of the auxiliary electronic expansion valve based on the economizer parameter and the exhaust parameter, specifically includes:

Comparing the economizer parameter with an initial target economizer parameter to obtain the state of the economizer parameter;

Whether to adjust the opening degree of the main electronic expansion valve and the opening degree of the auxiliary electronic expansion valve based on the exhaust parameter is determined according to the state of the economizer parameter.

In one of the preferred embodiments, determining whether to adjust the opening of the main electronic expansion valve and the opening of the auxiliary electronic expansion valve based on the exhaust parameter is determined according to the state of the economizer parameter, specifically including:

When the economizer parameter is the economizer superheat, the initial target economizer parameter is the initial target economizer superheat; if the state of the economizer superheat is not higher than the initial target economizer superheat heat, performing a process of adjusting the opening degree of the main electronic expansion valve and the opening degree of the auxiliary electronic expansion valve based on the exhaust gas parameter;

When the economizer parameter is the subcooling degree of the economizer, the initial target economizer parameter is the initial target economizer subcooling degree; if the state of the economizer subcooling degree is not lower than the initial target The subcooling degree of the economizer performs a process of adjusting the opening degree of the main electronic expansion valve and the opening degree of the auxiliary electronic expansion valve based on the exhaust gas parameter.

In one of the preferred embodiments, adjusting the opening degree of the main electronic expansion valve and the opening degree of the auxiliary electronic expansion valve based on the economizer parameter and the exhaust parameter includes:

comparing the exhaust parameter with the target exhaust parameter when the economizer parameter reaches the initial target economizer parameter;

When the exhaust gas parameter is not higher than the target exhaust gas parameter, keep the opening of the main electronic expansion valve constant, and adjust the auxiliary electronic expansion valve according to the economizer parameter and the initial target economizer parameter. The opening of the expansion valve;

When the exhaust gas parameter is higher than the target exhaust gas parameter, increase the initial target intake air superheat to obtain the increased target intake air superheat, according to the intake air superheat and the increased Adjust the opening degree of the main electronic expansion valve according to the final target suction superheat degree, and adjust the opening degree of the auxiliary electronic expansion valve according to the economizer parameter and the initial target economizer parameter.

In one of the preferred embodiments, adjusting the opening degree of the main electronic expansion valve and the opening degree of the auxiliary electronic expansion valve based on the economizer parameter and the exhaust parameter includes:

When the superheat degree of the economizer is lower than the initial target economizer superheat degree, comparing the exhaust parameter with the target exhaust parameter;

When the exhaust parameter reaches the target exhaust parameter, keep the opening of the main electronic expansion valve and the opening of the auxiliary electronic expansion valve unchanged;

When the exhaust gas parameter is higher than the target exhaust gas parameter, increase the initial target intake air superheat to obtain the increased target intake air superheat, according to the intake air superheat and the increased Adjust the opening degree of the main electronic expansion valve with the final target suction superheat degree; at the same time reduce the initial target economizer superheat degree to obtain the reduced target economizer superheat degree, according to the economizer superheat degree and the set adjust the opening of the auxiliary electronic expansion valve according to the reduced target economizer superheat;

When the exhaust gas parameter is lower than the target exhaust gas parameter, keep the opening of the main electronic expansion valve unchanged, and at the same time increase the initial target economizer superheat to obtain the increased target economizer superheat heat, adjusting the opening degree of the auxiliary electronic expansion valve according to the superheat degree of the economizer and the increased target economizer superheat degree;

When the subcooling degree of the economizer is higher than the initial target economizer subcooling degree, comparing the exhaust parameter with the target exhaust parameter;

When the exhaust parameter reaches the target exhaust parameter, keep the opening of the main electronic expansion valve and the opening of the auxiliary electronic expansion valve unchanged;

When the exhaust gas parameter is higher than the target exhaust gas parameter, adjust the opening degree of the main electronic expansion valve according to the suction superheat degree and the increased target suction superheat degree; at the same time, increase the The initial target economizer subcooling degree is obtained to obtain the increased target economizer subcooling degree, and the auxiliary electronic expansion valve is adjusted according to the economizer subcooling degree and the increased target economizer subcooling degree opening;

When the exhaust parameter is lower than the target exhaust parameter, keep the opening of the main electronic expansion valve unchanged, and reduce the initial target economizer subcooling degree to obtain the reduced target economizer subcooling degree, adjusting the opening degree of the auxiliary electronic expansion valve according to the economizer subcooling degree and the reduced target economizer subcooling degree.

In one of the preferred embodiments, adjusting the opening degree of the main electronic expansion valve and the opening degree of the auxiliary electronic expansion valve based on the economizer parameter and the exhaust parameter includes:

When the economizer superheat is higher than the initial target economizer superheat, increase the initial target suction superheat to obtain the increased target suction superheat, according to the suction superheat and the set Adjust the opening degree of the main electronic expansion valve according to the increased target suction superheat degree; also reduce the initial target economizer superheat degree to obtain the reduced target economizer superheat degree, according to the economizer superheat degree heat and the reduced target economizer superheat adjust the opening of the auxiliary electronic expansion valve;

When the subcooling degree of the economizer is lower than the initial target economizer subcooling degree, increase the initial target suction superheat degree to obtain the increased target suction superheat degree, according to the suction superheat degree and the increased target suction superheat degree to adjust the opening degree of the main electronic expansion valve; also increase the initial target economizer subcooling degree to obtain the increased target economizer subcooling degree, according to the The opening degree of the auxiliary electronic expansion valve is adjusted according to the economizer subcooling degree and the increased target economizer subcooling degree.

In preferred embodiments wherein, the method also includes:

Before executing the first control process and the second control process, the opening degree of the main electronic expansion valve is adjusted to the initial main valve opening degree, and the opening degree of the auxiliary electronic expansion valve is adjusted to the initial auxiliary valve opening degree opening.

In preferred embodiments wherein, the method also includes:

During the first control process, the opening degree of the auxiliary electronic expansion valve is kept at the initial auxiliary valve opening degree.

In order to achieve the above-mentioned purpose of the invention, the control device of the heat pump unit provided by the present invention is realized by the following technical solutions:

A control device for a heat pump unit, the device comprising:

A suction superheat obtaining unit, configured to obtain the suction superheat;

The economizer parameter acquisition unit is used to acquire the economizer parameter; the economizer parameter is the degree of superheat of the economizer or the degree of subcooling of the economizer;

An exhaust parameter acquisition unit, configured to acquire an exhaust parameter; the exhaust parameter is exhaust superheat or exhaust temperature;

A suction superheat judging unit, configured to judge whether the suction superheat reaches an initial target suction superheat;

The first processing unit is configured to execute a first control process when the degree of suction superheat does not reach the initial target degree of superheat of the suction air: adjust the calculated degree of superheat according to the degree of superheat of the suction air and the initial target degree of superheat of the suction air Describe the opening of the main electronic expansion valve;

The second processing unit is configured to execute a second control process when the suction superheat reaches the initial target suction superheat: adjust the main electronic expansion valve based on the economizer parameter and the exhaust parameter and the opening of the auxiliary electronic expansion valve.

The present invention also provides a heat pump unit, which includes a processor, a memory, and a computer program stored on the memory, the processor is configured to execute the computer program to implement the above heat pump control method.

Compared with prior art, advantage and positive effect of the present invention are:

In the control method and control device of the heat pump unit provided by the present invention, firstly, the suction superheat is used as a rough adjustment parameter to adjust the opening of the main electronic expansion valve, so that the main electronic expansion valve can quickly reach a reasonable opening, and then the economizer parameter and exhaust The gas parameter is used as a fine-tuning parameter to fine-tune the opening of the main electronic expansion valve and the opening of the auxiliary electronic expansion valve; Linkage adjustment realizes the coupling control of the opening of the two expansion valves, realizes the optimal control of the refrigerant flow rate of the main refrigerant circulation circuit and the refrigerant flow rate of the supplementary gas auxiliary circuit, and ensures that the refrigerant flow rate in different flow paths reaches an optimized state, thereby realizing The optimization of unit efficiency ensures the stable and efficient operation of the unit.

Other features and advantages of the present invention will become clearer after reading the detailed description of the present invention in conjunction with the accompanying drawings.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the accompanying drawings that need to be used in the embodiments. Obviously, the accompanying drawings in the following description are some embodiments of the present invention. For Those of ordinary skill in the art can also obtain other drawings based on these drawings without making creative efforts.

Fig. 1 is a schematic flow chart of an embodiment of the heat pump unit control method of the present invention;

Fig. 2 is a schematic flow chart of another embodiment of the heat pump unit control method of the present invention;

Fig. 3 is a schematic flowchart of another embodiment of the heat pump unit control method of the present invention;

Fig. 4 is a structural schematic diagram of an embodiment of the heat pump unit control device of the present invention;

Fig. 5 is a structural schematic diagram of an embodiment of the heat pump unit of the present invention.

Implementation

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments.

It should be noted that the technical solutions of the various embodiments of the present invention can be combined with each other, but it must be based on the realization of those skilled in the art. When the combination of technical solutions is contradictory or cannot be realized, it should be considered as The combination of technical solutions does not exist, nor is it within the scope of protection required by the present invention.

For a heat pump unit with a main electronic expansion valve and an auxiliary electronic expansion valve, the existing technology usually uses independent control to adjust the opening of the two expansion valves. However, the change of the opening of each expansion valve not only affects the expansion valve. The refrigerant flow rate of the refrigerant branch circuit where it is located will also affect the refrigerant flow rate in the refrigerant flow circuit of the entire heat pump unit, and the change of the refrigerant flow rate of the entire unit will affect the refrigerant flow rate of each refrigerant branch circuit. Therefore, The way that the expansion valves in different branches are controlled independently of each other is difficult to obtain the optimal control of flow in different branches. In order to solve the problems of the prior art, the present invention creatively proposes to carry out linkage adjustment on the main electronic expansion valve and the auxiliary electronic expansion valve of the heat pump unit, realize the coupling control of the opening of the two expansion valves, and achieve the optimal control of the flows of different refrigerant flow paths .

Figure 1 is a schematic flow chart of an embodiment of the control method of the heat pump unit of the present invention. In this embodiment, the heat pump unit includes a main electronic expansion valve arranged in the main circuit of the refrigerant cycle and an auxiliary air supply circuit where the economizer is located. Auxiliary electronic expansion valve.

For a heat pump unit with a main electronic expansion valve and an auxiliary electronic expansion valve, this embodiment adopts the following process to adjust the opening of the electronic expansion valve.

Step 101: Obtain the suction superheat degree, the economizer parameter and the exhaust parameter.

The acquisition method of the degree of suction superheat adopts the prior art. In one embodiment, the suction superheat degree is determined by the difference between the suction temperature of the heat pump unit and the pressure saturation temperature of the suction side. The suction temperature is detected by a temperature detection device installed on the suction side of the compressor, and the pressure saturation temperature of the suction side is calculated by detecting the pressure on the suction side.

The economizer parameter can be the superheat degree of the economizer, and also can be the subcooling degree of the economizer, and the acquisition methods are all in the prior art. In one embodiment, the degree of superheat of the economizer is determined by the difference between the outlet temperature of the economizer auxiliary road and the inlet temperature of the economizer auxiliary road.

The exhaust parameter can be exhaust superheat or exhaust temperature, and the acquisition methods are all in the prior art. In one embodiment, the degree of superheat of the exhaust gas is corrected and determined according to the difference between the exhaust gas temperature and the outlet water temperature. The exhaust gas temperature and the outlet water temperature are detected by the temperature detection device arranged at the corresponding position.

Step 102: Judging whether the degree of superheat of the intake air has reached the initial target degree of superheat of the intake air. If yes, go to step 104; otherwise, go to step 103.

The initial target suction superheat is a preset value. When the suction superheat reaches the initial target suction superheat, the corresponding main electronic expansion valve opening is a reasonable opening. At this time, the heat pump unit can run relatively stably.

Step 103: When the suction superheat degree does not reach the initial target suction superheat degree, perform a first control process: adjust the opening degree of the main electronic expansion valve according to the suction superheat degree and the initial target suction superheat degree.

By adjusting the opening degree of the main electronic expansion valve, the suction superheat can reach the initial target suction superheat. If the degree of suction superheat has not reached the initial target degree of suction superheat, adjust the opening degree of the main electronic expansion valve. Specifically, the opening of the main electronic expansion valve is adjusted according to the current suction superheat and the initial target suction superheat until the suction superheat reaches the initial target suction superheat. The specific adjustment process is realized by using the existing technology . In some embodiments, the opening of the main electronic expansion valve is adjusted according to the difference between the suction superheat and the initial target suction superheat and/or the change speed of the suction superheat, so that the suction superheat reaches the initial target suction superheat. superheat.

Step 104: When the suction superheat degree reaches the initial target suction superheat degree, execute the second control process: adjust the opening degree of the main electronic expansion valve and the opening degree of the auxiliary electronic expansion valve based on the economizer parameter and the exhaust parameter.

In the embodiment shown in Fig. 1, the adjustment of the opening of the expansion valve adopts a control strategy implemented in two steps:

The first step is to execute the first control process, and use the suction superheat as a rough adjustment parameter to roughly adjust the opening of the main electronic expansion valve so that the suction superheat reaches the initial target suction superheat, so that the main The electronic expansion valve quickly reaches a reasonable opening to ensure that the heat pump unit can be in a relatively stable operating state quickly. In the second step, after the suction superheat reaches the initial target suction superheat and the main electronic expansion valve reaches a relatively reasonable opening, the second control process is executed, and the economizer parameters and exhaust parameters are used as fine adjustment parameters. Adjust the opening of the main electronic expansion valve and the opening of the auxiliary electronic expansion valve, and perform linkage adjustment on the main electronic expansion valve and the auxiliary electronic expansion valve to realize the coupling control of the opening of the two expansion valves and realize the refrigeration of the main circuit of the refrigerant cycle. The optimal control of the refrigerant flow and the refrigerant flow of the supplementary gas auxiliary circuit ensures that the refrigerant flow in different flow paths reaches an optimized state, thereby realizing the optimization of the unit efficiency and ensuring the stable and efficient operation of the unit.

Fig. 2 is a schematic flowchart of another embodiment of the control method of the heat pump unit according to the present invention. In this embodiment, the heat pump unit includes a main electronic expansion valve arranged in the main circuit of the refrigerant cycle and an auxiliary air supplementary circuit arranged in the economizer. Auxiliary electronic expansion valve in. For a heat pump unit with a main electronic expansion valve and an auxiliary electronic expansion valve, this embodiment adopts the following process to adjust the opening of the electronic expansion valve.

Step 201: Adjust the opening of the main electronic expansion valve to the initial opening of the main valve, and adjust the opening of the auxiliary electronic expansion valve to the initial opening of the auxiliary valve.

Both the initial main valve opening and the initial auxiliary valve opening are preset values. After the heat pump unit is turned on, first adjust the main electronic expansion valve and the auxiliary electronic expansion valve to the corresponding initial opening degrees, and then perform subsequent adjustments at the initial opening degrees to improve the adjustment efficiency.

Step 202: Obtain the suction superheat degree, the economizer parameter and the exhaust parameter.

For the specific implementation of this step, refer to the corresponding description of the embodiment in FIG. 1 .

Step 203: Judging whether the degree of superheat of the intake air has reached the initial target degree of superheat of the intake air. If yes, go to step 205; otherwise, go to step 204.

The initial target suction superheat is a preset value. When the suction superheat reaches the initial target suction superheat, the corresponding main electronic expansion valve opening is a reasonable opening. At this time, the heat pump unit can run relatively stably.

Step 204: Execute the first control process: adjust the opening degree of the main electronic expansion valve according to the suction superheat degree and the initial target suction superheat degree; keep the opening degree of the auxiliary electronic expansion valve at the initial auxiliary valve opening degree.

For the adjustment of the opening degree of the main electronic expansion valve, please refer to the corresponding description of the embodiment in FIG. 1 . Moreover, in the process of adjusting the opening degree of the main electronic expansion valve by using the suction superheat degree, the opening degree of the auxiliary electronic expansion valve remains unchanged from the initial auxiliary valve opening degree.

Step 205: Execute the second control process. After the suction superheat reaches the initial target suction superheat, the second control process will be executed, specifically, the fine adjustment process of step 206 and step 207 will be executed.

Step 206: Comparing the economizer parameter with the initial target economizer parameter to obtain the state of the economizer parameter.

The initial target economizer parameter is a preset value. When the economizer parameter reaches the initial target economizer parameter, the opening degree of the corresponding auxiliary electronic expansion valve is a reasonable opening degree, and the compressor can obtain reasonable supplementary air.

In the second control process, firstly, based on the economizer parameters, it is judged whether the economizer of the heat pump unit is effective in exchanging heat, and whether it provides reasonable supplementary air for the compressor. Specifically, the state of the economizer parameter reflected by the relationship between the economizer parameter and the initial target economizer parameter is used as a benchmark.

Step 207: Determine whether to adjust the opening degree of the main electronic expansion valve and the opening degree of the auxiliary electronic expansion valve based on the exhaust parameter according to the state of the economizer parameter.

The exhaust parameter does not always participate in the adjustment of the opening of the main electronic expansion valve and the auxiliary electronic expansion valve, but decides whether to use the exhaust parameter to participate in the adjustment of the valve opening according to the state of the economizer parameter.

In this embodiment, in the second control process, the state of the economizer parameter is first judged, based on the state of the economizer parameter, the judgment of the state of the supplementary gas auxiliary road where the economizer is located is realized, and then according to the state of the economizer parameter, it is determined whether the exhaust The gas parameter participates in the adjustment of the valve opening as a control parameter. With this control strategy, the fine adjustment of the valve opening based on the economizer parameters and the fine adjustment of the valve opening based on the exhaust parameters are realized, combined with the coarse adjustment of the valve opening based on the suction superheat, the main electronic expansion is realized. The hierarchical coupling adjustment of the valve and the auxiliary electronic expansion valve further improves the adjustment accuracy and efficiency, and realizes the optimal control of the refrigerant flow in the main circuit of the refrigerant cycle and the refrigerant flow in the auxiliary air supplementary circuit, ensuring that the The refrigerant flow rate reaches an optimized state, thereby realizing the optimization of the efficiency of the unit and ensuring the stable and efficient operation of the unit.

In some embodiments, when the economizer parameter is an economizer superheat, the initial target economizer parameter is an initial target economizer superheat. If the superheat of the economizer is not higher than the initial target economizer superheat, the exhaust parameter participates in the adjustment of the valve opening, and the adjustment of the opening of the main electronic expansion valve and the opening of the auxiliary electronic expansion valve is performed based on the exhaust parameter. process; otherwise, the exhaust parameter does not participate in the adjustment of the valve opening.

In some other embodiments, when the economizer parameter is the subcooling degree of the economizer, the initial target economizer parameter is the initial target economizer subcooling degree. If the subcooling degree of the economizer is not lower than the initial target economizer subcooling degree, the exhaust parameter participates in the adjustment of the valve opening, and the adjustment of the opening of the main electronic expansion valve and the opening of the auxiliary electronic expansion valve is performed based on the exhaust parameter. degree process; otherwise, the exhaust parameter does not participate in the adjustment of the valve opening degree.

Fig. 3 is a schematic flow chart of another embodiment of the control method of the heat pump unit of the present invention, specifically, the specific flow of the second control process for the heat pump unit with the main electronic expansion valve and the auxiliary electronic expansion valve. In this embodiment, firstly, the opening degree of the main electronic expansion valve is roughly adjusted based on the degree of suction superheat by using the method shown in Figure 1 and Figure 2, and the degree of suction superheat reaches the initial target degree of suction superheat. Then a second control process is executed to adjust the opening degree of the main electronic expansion valve and the opening degree of the auxiliary electronic expansion valve based on the economizer parameter and the exhaust parameter. Moreover, in this embodiment, the economizer parameter is the degree of superheat of the economizer, and the exhaust parameter is the degree of superheat of the exhaust gas or the temperature of the exhaust gas.

As shown in FIG. 3 , in this embodiment, the following process is used to execute the second control process to realize the adjustment of the opening degree of the main electronic expansion valve and the opening degree of the auxiliary electronic expansion valve.

Step 301: Compare the economizer superheat degree with the initial target economizer superheat degree, determine that the economizer superheat degree is lower than, reach or higher than the defrosting target economizer superheat degree, and then execute different controls according to different states .

Step 310: When the economizer superheat degree is lower than the initial target economizer superheat degree, execute the control from step 311 to step 315. In this state, the exhaust parameters participate in the adjustment of the openings of the two valves, and different adjustment control strategies are implemented based on the different states of the exhaust parameters.

Step 311: Determine whether the exhaust parameter reaches the target exhaust parameter. If yes, go to step 312; otherwise, go to step 313.

The target exhaust parameter is a preset value. If the exhaust parameter is the exhaust superheat, the target exhaust parameter is the target exhaust superheat; if the exhaust parameter is the exhaust temperature, the target exhaust parameter is the target exhaust temperature .

Step 312: Keep the opening degrees of the main electronic expansion valve and the auxiliary electronic expansion valve unchanged.

If step 311 determines that the exhaust gas parameter reaches the target exhaust gas parameter, the openings of the main electronic expansion valve and the auxiliary electronic expansion valve remain unchanged to prevent exhaust temperature protection from affecting the normal operation of the system.

Step 313: Determine whether the exhaust parameter is higher than the target exhaust parameter. If yes, go to step 314; otherwise, go to step 315.

If it is determined in step 311 that the exhaust gas parameter has not reached the target exhaust gas parameter, it is further judged whether the exhaust gas parameter is higher than the target exhaust gas parameter, and different controls are executed according to the judgment result.

Step 314: Increase the initial target suction superheat, adjust the opening of the main electronic expansion valve; decrease the initial target superheat of the economizer, and adjust the opening of the auxiliary electronic expansion valve.

If it is determined in step 313 that the exhaust gas parameter is higher than the target exhaust gas parameter, the initial target suction superheat is increased to obtain the increased target suction superheat, and according to the suction superheat and the increased target suction superheat Adjust the opening of the main electronic expansion valve so that the opening of the main electronic expansion valve is closed to avoid excessive exhaust gas temperature.

At the same time, reduce the initial target economizer superheat to obtain the reduced target economizer superheat, adjust the opening of the auxiliary electronic expansion valve according to the economizer superheat and the reduced target economizer superheat, so that the auxiliary electronic expansion The opening of the valve becomes larger, and the compressor is rapidly cooled by utilizing the increase in the refrigerant flow rate of the gas supply branch.

Step 315: Keep the opening degree of the main electronic expansion valve unchanged; increase the initial target superheat degree of the economizer, and adjust the opening degree of the auxiliary electronic expansion valve.

If it is judged in step 313 that the exhaust gas parameter is not higher than the target exhaust gas parameter, combined with the judgment in step 311, it can be known that the exhaust gas parameter is lower than the target exhaust gas parameter at this time. Then the opening degree of the main electronic expansion valve remains unchanged, and at the same time increase the initial target economizer superheat degree to obtain the increased target economizer superheat degree, and adjust the auxiliary The opening degree of the electronic expansion valve reduces the opening degree of the auxiliary electronic expansion valve, reduces the flow rate of the refrigerant in the supplementary gas branch, and makes the superheat degree of the economizer reach a larger superheat degree.

Step 320: When the superheat degree of the economizer is in the state of reaching the initial target economizer superheat degree, execute the control process from step 321 to step 323. In this state, the exhaust parameters also participate in the adjustment of the openings of the two valves, and different adjustment control strategies are implemented based on the different states of the exhaust parameters.

Step 321: Determine whether the exhaust gas parameter is higher than the target exhaust gas parameter. If yes, go to step 322; otherwise, go to step 323.

Step 322: Increase the initial target suction superheat, adjust the opening of the main electronic expansion valve; adjust the opening of the auxiliary electronic expansion valve according to the initial target superheat of the economizer.

If it is determined in step 321 that the exhaust gas parameter is higher than the target exhaust gas parameter, then increase the initial target suction superheat to obtain the increased target suction superheat, according to the suction superheat and the increased target suction superheat The heat adjusts the opening degree of the main electronic expansion valve so that the opening degree of the main electronic expansion valve is closed to avoid excessive exhaust gas temperature. At the same time, since the superheat degree of the economizer in step 320 has reached the initial target economizer superheat degree, the initial target economizer superheat degree is not changed, and the opening degree of the auxiliary electronic expansion valve is adjusted according to the economizer parameter and the initial target economizer superheat degree. That is, the opening degree of the auxiliary electronic expansion valve is automatically adjusted according to the initial target economizer superheat degree. At this time, the system capacity of the heat pump unit reaches the best state within the normal operating range.

Step 323: Keep the opening degree of the main electronic expansion valve unchanged; adjust the opening degree of the auxiliary electronic expansion valve according to the initial target superheat degree of the economizer.

If it is determined in step 321 that the exhaust parameter is not higher than the target exhaust parameter, then keep the opening of the main electronic expansion valve unchanged, and at the same time adjust the opening of the auxiliary electronic expansion valve according to the superheat of the economizer and the initial target economizer superheat, That is, the opening degree of the auxiliary electronic expansion valve is automatically adjusted according to the initial target economizer superheat degree.

Step 330: Execute the control of step 331 when the economizer superheat degree is higher than the initial target economizer superheat degree.

Step 331: Increase the initial target suction superheat and adjust the opening of the main electronic expansion valve; decrease the initial target economizer superheat and adjust the opening of the auxiliary electronic expansion valve.

When the superheat degree of the economizer is higher than the initial target economizer superheat degree, the influence of the exhaust parameters is not considered, but the opening degrees of both valves are adjusted. Specifically, increase the initial target suction superheat to obtain the increased target suction superheat, adjust the opening of the main electronic expansion valve according to the suction superheat and the increased target suction superheat, so that the main electronic The opening of the expansion valve is small. At the same time, the initial target economizer superheat is also reduced to obtain the reduced target economizer superheat, and the opening of the auxiliary electronic expansion valve is adjusted according to the economizer superheat and the reduced target economizer superheat, so that the auxiliary electronic The opening of the expansion valve becomes larger, increasing the refrigerant flow rate in the supplementary gas branch to reduce the heat exchange temperature difference of the economizer.

It should be understood that the above-mentioned process is a control process of a control cycle, and the above-mentioned process will be executed cyclically during the entire operation process of the heat pump unit.

The above process is described using the economizer superheat as the economizer parameter, and in some other embodiments, the economizer parameter may also be the economizer subcooling degree. When the subcooling degree of the economizer is used as the parameter of the economizer, some steps in Fig. 3 are adjusted. details as follows:

When the subcooling degree of the economizer is higher than the initial target economizer subcooling degree, the exhaust parameters participate in the adjustment of the opening of the two valves, and different adjustment control strategies are implemented based on the different states of the exhaust parameters. Specifically, firstly, the exhaust parameter is compared with the target exhaust parameter, and different controls are executed according to the comparison result. When the exhaust parameter reaches the target exhaust parameter, the opening of the electronic expansion valve and the opening of the auxiliary electronic expansion valve remain unchanged. When the exhaust parameter is higher than the target exhaust parameter, the opening of the main electronic expansion valve is adjusted according to the suction superheat and the increased target suction superheat; at the same time, the initial target economizer subcooling is increased to obtain an increase The final target economizer subcooling degree, and adjust the opening degree of the auxiliary electronic expansion valve according to the economizer subcooling degree and the increased target economizer subcooling degree. When the exhaust parameter is lower than the target exhaust parameter, keep the opening of the main electronic expansion valve unchanged, and at the same time reduce the initial target economizer subcooling degree to obtain the reduced target economizer subcooling degree. The cooling degree and the reduced target economizer subcooling degree adjust the opening degree of the auxiliary electronic expansion valve.

When the subcooling degree of the economizer reaches the initial target economizer subcooling degree, the exhaust parameters also participate in the adjustment of the opening of the two valves, and different adjustment control strategies are implemented based on the different states of the exhaust parameters. Specifically, when the exhaust parameter is higher than the target exhaust parameter, increase the initial target suction superheat and adjust the opening of the main electronic expansion valve; at the same time, adjust the opening of the auxiliary electronic expansion valve according to the initial target economizer subcooling Spend. When the exhaust parameter is not higher than the target exhaust parameter, the opening of the main electronic expansion valve is kept constant, and at the same time, the opening of the auxiliary electronic expansion valve is adjusted according to the initial target economizer subcooling degree.

When the subcooling degree of the economizer is higher than the initial target subcooling degree of the economizer, the influence of the exhaust parameters is not considered, but the opening degrees of both valves are adjusted. Specifically, increase the initial target suction superheat to obtain the increased target suction superheat, adjust the opening of the main electronic expansion valve according to the suction superheat and the increased target suction superheat, so that the main electronic The opening of the expansion valve is small. At the same time, the initial target economizer subcooling degree is also increased to obtain the increased target economizer subcooling degree, and the opening of the auxiliary electronic expansion valve is adjusted according to the economizer subcooling degree and the increased target economizer subcooling degree .

Fig. 4 is a schematic structural diagram of an embodiment of the heat pump unit control device of the present invention. In this embodiment, the heat pump unit includes a main electronic expansion valve arranged in the main circuit of the refrigerant cycle and an auxiliary electronic expansion valve arranged in the auxiliary air supply circuit where the economizer is located. The structural units included in the control device of the heat pump unit, the functions of the structural units and the relationship between them are described in detail as follows:

Heat pump unit controls include:

The intake air superheat acquisition unit 41 is configured to acquire the intake air superheat.

The economizer parameter acquiring unit 42 is configured to acquire the economizer parameter. Wherein, the economizer parameter is the degree of superheat of the economizer or the degree of subcooling of the economizer.

The exhaust parameter acquiring unit 43 is configured to acquire the exhaust parameter. Wherein, the exhaust parameter is exhaust superheat or exhaust temperature.

The intake air superheat degree judging unit 44 is configured to determine whether the intake air superheat degree acquired by the intake air superheat degree acquisition unit 41 reaches an initial target intake air superheat degree.

The first processing unit 45 is configured to execute the first control process when the output result of the intake air superheat determination unit 44 is that the intake air superheat has not reached the initial target intake air superheat: according to the intake air superheat acquired by the intake air superheat acquisition unit 41 Suction superheat and initial target suction superheat adjust the opening of the main electronic expansion valve.

The second processing unit 46 is configured to execute the second control process when the output result of the intake air superheat degree judging unit 44 is that the intake air superheat degree reaches the initial target intake air superheat degree: based on the economizer value obtained by the economizer parameter acquisition unit 42 The exhaust parameter obtained by the parameter and exhaust parameter acquisition unit 43 adjusts the opening degree of the main electronic expansion valve and the opening degree of the auxiliary electronic expansion valve.

The control device with the above-mentioned structure runs corresponding software programs and performs corresponding functions, and controls the heat pump unit according to the process of the embodiment of the control method for the heat pump unit in Figure 1 to Figure 3 and its preferred embodiment, to achieve the corresponding technical effects of the method embodiment .

Fig. 5 shows a schematic structural view of an embodiment of the heat pump unit of the present invention. The heat pump unit includes a processor 51, a memory 52, and a computer program 521 stored on the memory 52. The processor 51 is configured to execute the computer program 521 to realize the control method of the embodiment of the heat pump unit in FIGS. 1 to 3 and the control method of the preferred embodiment. , and achieve the technical effects of the corresponding embodiments.

The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art can still understand the foregoing embodiments. Modifications are made to the technical solutions described, or equivalent replacements are made to some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions claimed in the present invention.

Claims (9)

1. A heat pump unit control method, the heat pump unit including a main electronic expansion valve provided in a refrigerant circulation main path and an auxiliary electronic expansion valve provided in a gas-supplementing auxiliary path where an economizer is located, the method comprising:

the unit operates to acquire the air suction superheat degree, the economizer parameter and the exhaust parameter;

judging whether the suction superheat degree reaches an initial target suction superheat degree or not;

when the suction superheat degree does not reach the initial target suction superheat degree, executing a first control process: adjusting the opening of the main electronic expansion valve according to the suction superheat degree and the initial target suction superheat degree;

and when the suction superheat degree reaches the initial target suction superheat degree, executing a second control process: adjusting the opening of the main electronic expansion valve and the opening of the auxiliary electronic expansion valve based on the economizer parameter and the exhaust parameter;

the economizer parameter is economizer superheat or economizer subcooling; the exhaust parameter is exhaust superheat degree or exhaust temperature;

and adjusting the opening of the main electronic expansion valve and the opening of the auxiliary electronic expansion valve based on the economizer parameter and the exhaust parameter, wherein the method specifically comprises the following steps of:

Comparing the economizer parameter with an initial target economizer parameter to obtain a state of the economizer parameter;

and determining whether to adjust the opening of the main electronic expansion valve and the opening of the auxiliary electronic expansion valve based on the exhaust parameters according to the state of the economizer parameters.

2. The heat pump unit control method according to claim 1, wherein determining whether to adjust the opening degree of the main electronic expansion valve and the opening degree of the auxiliary electronic expansion valve based on the exhaust gas parameter according to the state of the economizer parameter, specifically comprises:

when the economizer parameter is the economizer superheat, the initial target economizer parameter is an initial target economizer superheat; if the state of the economizer superheat degree is not higher than the initial target economizer superheat degree, executing a process of adjusting the opening degree of the main electronic expansion valve and the opening degree of the auxiliary electronic expansion valve based on the exhaust parameter;

when the economizer parameter is the economizer subcooling degree, the initial target economizer parameter is an initial target economizer subcooling degree; and if the state of the economizer supercooling degree is not lower than the initial target economizer supercooling degree, executing a process of adjusting the opening degree of the main electronic expansion valve and the opening degree of the auxiliary electronic expansion valve based on the exhaust gas parameter.

3. The heat pump unit control method according to claim 2, wherein adjusting the opening degree of the main electronic expansion valve and the opening degree of the auxiliary electronic expansion valve based on the economizer parameter and the exhaust gas parameter, comprises:

comparing the exhaust gas parameter with a target exhaust gas parameter when the economizer parameter reaches the initial target economizer parameter;

when the exhaust parameter is not higher than the target exhaust parameter, keeping the opening of the main electronic expansion valve unchanged, and adjusting the opening of the auxiliary electronic expansion valve according to the economizer parameter and the initial target economizer parameter;

and when the exhaust parameter is higher than the target exhaust parameter, increasing the initial target air suction superheat degree to obtain an increased target air suction superheat degree, adjusting the opening of the main electronic expansion valve according to the air suction superheat degree and the increased target air suction superheat degree, and adjusting the opening of the auxiliary electronic expansion valve according to the economizer parameter and the initial target economizer parameter.

4. The heat pump unit control method according to claim 2, wherein adjusting the opening degree of the main electronic expansion valve and the opening degree of the auxiliary electronic expansion valve based on the economizer parameter and the exhaust gas parameter, comprises:

Comparing the exhaust gas parameter with a target exhaust gas parameter when the economizer superheat is less than an initial target economizer superheat;

when the exhaust parameter reaches the target exhaust parameter, keeping the opening of the main electronic expansion valve and the opening of the auxiliary electronic expansion valve unchanged;

when the exhaust parameter is higher than the target exhaust parameter, increasing the initial target air suction superheat degree to obtain an increased target air suction superheat degree, and adjusting the opening of the main electronic expansion valve according to the air suction superheat degree and the increased target air suction superheat degree; simultaneously reducing the initial target economizer superheat degree, obtaining a reduced target economizer superheat degree, and adjusting the opening of the auxiliary electronic expansion valve according to the economizer superheat degree and the reduced target economizer superheat degree;

when the exhaust parameter is lower than the target exhaust parameter, keeping the opening of the main electronic expansion valve unchanged, increasing the initial target economizer superheat degree, obtaining the increased target economizer superheat degree, and adjusting the opening of the auxiliary electronic expansion valve according to the economizer superheat degree and the increased target economizer superheat degree;

Comparing the exhaust gas parameter to the target exhaust gas parameter when the economizer degree of subcooling is greater than an initial target economizer degree of subcooling;

when the exhaust parameter reaches the target exhaust parameter, keeping the opening of the main electronic expansion valve and the opening of the auxiliary electronic expansion valve unchanged;

when the exhaust parameter is higher than the target exhaust parameter, adjusting the opening of the main electronic expansion valve according to the suction superheat degree and the increased target suction superheat degree; simultaneously increasing the initial target economizer supercooling degree to obtain an increased target economizer supercooling degree, and adjusting the opening of the auxiliary electronic expansion valve according to the economizer supercooling degree and the increased target economizer supercooling degree;

and when the exhaust parameter is lower than the target exhaust parameter, keeping the opening of the main electronic expansion valve unchanged, reducing the initial target economizer supercooling degree, obtaining the reduced target economizer supercooling degree, and adjusting the opening of the auxiliary electronic expansion valve according to the economizer supercooling degree and the reduced target economizer supercooling degree.

5. The heat pump unit control method according to claim 2, wherein adjusting the opening degree of the main electronic expansion valve and the opening degree of the auxiliary electronic expansion valve based on the economizer parameter and the exhaust gas parameter, comprises:

When the superheat degree of the economizer is higher than the initial target superheat degree of the economizer, increasing the initial target suction superheat degree to obtain an increased target suction superheat degree, and adjusting the opening of the main electronic expansion valve according to the suction superheat degree and the increased target suction superheat degree; the initial target economizer superheat degree is reduced, the reduced target economizer superheat degree is obtained, and the opening of the auxiliary electronic expansion valve is adjusted according to the economizer superheat degree and the reduced target economizer superheat degree;

when the economizer supercooling degree is lower than the initial target economizer supercooling degree, increasing the initial target air suction superheat degree to obtain an increased target air suction superheat degree, and adjusting the opening of the main electronic expansion valve according to the air suction superheat degree and the increased target air suction superheat degree; and further increasing the initial target economizer supercooling degree, obtaining an increased target economizer supercooling degree, and adjusting the opening degree of the auxiliary electronic expansion valve according to the economizer supercooling degree and the increased target economizer supercooling degree.

6. The heat pump unit control method according to any one of claims 1 to 5, characterized in that the method further comprises:

Before the first control process and the second control process are executed, the opening degree of the main electronic expansion valve is adjusted to an initial main valve opening degree, and the opening degree of the auxiliary electronic expansion valve is adjusted to an initial auxiliary valve opening degree.

7. The heat pump assembly control method of claim 6, further comprising:

and in the first control process, maintaining the opening degree of the auxiliary electronic expansion valve to be the initial auxiliary valve opening degree.

8. A heat pump unit control apparatus including a main electronic expansion valve provided in a refrigerant circulation main path and an auxiliary electronic expansion valve provided in a supplementary air path where an economizer is located, the apparatus comprising:

the air suction superheat degree acquisition unit is used for acquiring the air suction superheat degree;

an economizer parameter acquisition unit configured to acquire an economizer parameter; the economizer parameter is economizer superheat or economizer subcooling;

an exhaust parameter acquisition unit configured to acquire an exhaust parameter; the exhaust parameter is exhaust superheat degree or exhaust temperature;

the air suction superheat degree judging unit is used for judging whether the air suction superheat degree reaches an initial target air suction superheat degree or not;

A first processing unit configured to execute a first control procedure when the suction superheat degree does not reach the initial target suction superheat degree: adjusting the opening of the main electronic expansion valve according to the suction superheat degree and the initial target suction superheat degree;

a second processing unit, configured to execute a second control procedure when the suction superheat degree reaches the initial target suction superheat degree: adjusting the opening of the main electronic expansion valve and the opening of the auxiliary electronic expansion valve based on the economizer parameter and the exhaust parameter;

and adjusting the opening of the main electronic expansion valve and the opening of the auxiliary electronic expansion valve based on the economizer parameter and the exhaust parameter, wherein the method specifically comprises the following steps of:

comparing the economizer parameter with an initial target economizer parameter to obtain a state of the economizer parameter;

and determining whether to adjust the opening of the main electronic expansion valve and the opening of the auxiliary electronic expansion valve based on the exhaust parameters according to the state of the economizer parameters.

9. A heat pump assembly comprising a processor, a memory and a computer program stored on the memory, characterized in that the processor is configured to execute the computer program to implement the heat pump assembly control method according to any one of the preceding claims 1 to 7.