Control method and control device of air conditioning system and air conditioning system

Abstract

The invention provides a control method and device of an air conditioning system and the air conditioning system using the control method or provided with the control device. When the air conditioning system is switched to a heating mode, the hot air valve and the liquid injection valve are opened, the main hot valve is closed, the condenser does not participate in refrigerant circulation any more, the temperature of a refrigerant is increased through heating of a compressor motor, the heated refrigerant exchanges heat with the outside through the evaporator, and the indoor environment temperature is increased. Meanwhile, one part of the refrigerant flowing out of the evaporator flows into the compressor to continue the heating cycle, and the other part of the refrigerant flows into the liquid storage device through the liquid injection valve, so that the flow of the refrigerant participating in the refrigeration cycle is reduced, and the energy utilization rate is improved. And when the air conditioning system operates for the specified time or the indoor environment temperature reaches the specified heating temperature, the liquid injection valve is closed, it is ensured that the air conditioning system has enough refrigerant to participate in the heating cycle, and the heating performance of the air conditioning system is prevented from being continuously reduced.

Description

Technical Field

[0001] This application relates to the field of air conditioning, specifically to a control method for an air conditioning system and a control device for executing the control method, as well as an air conditioning system using the control method or having the control device. Background Technology

[0002] In existing air conditioning systems, when the load changes or the system's operating mode changes, the refrigerant flow can be adjusted using an FCV (Flow Control Valve) device. This means adjusting the refrigerant flow according to the system's current actual load demand. When the load is low, adjusting the FCV device reduces the refrigerant flow in the refrigerant cycle, preventing excessive cooling and thus adapting to the load and saving energy. When the load is high, adjusting the FCV device increases the refrigerant flow in the refrigerant cycle to meet higher cooling or heating demands.

[0003] Under normal circumstances, the indoor heat load in winter is less than the indoor cooling load in summer. When the air conditioning system switches to heating mode, the required refrigerant is less than that in cooling mode. The flow of refrigerant into the receiver can be controlled by adjusting the valve in the FCV device, thereby reducing the refrigerant flow in the refrigerant circulation pipeline to adapt to the load and save energy.

[0004] However, if the FCV unit controls cause excessive refrigerant to flow into the receiver, resulting in insufficient refrigerant flow in the refrigerant circulation line, the air conditioning system will be unable to provide the required load. Summary of the Invention

[0005] This application aims to provide a control method and control device for an air conditioning system, and an air conditioning system using the control method or having the control device, so as to at least solve or alleviate some of the problems existing in the prior art.

[0006] This application provides a control method for an air conditioning system. The applicable air conditioning system includes a compressor, a main heat valve, a condenser, a receiver-of-flow tank, an expansion valve, and an evaporator, connected sequentially to form a refrigerant circulation loop. It also includes a hot gas valve connected at one end to the compressor outlet and the other end to the evaporator inlet, and a liquid injection valve connected at one end to the evaporator outlet and the other end to the receiver-of-flow tank. The control method includes: an air conditioning system setting mode determination step, determining whether the air conditioning system is set to a specified mode; a hot gas valve opening step, opening the hot gas valve; a main heat valve closing step, closing the main heat valve based on the determination result of the air conditioning system setting mode determination step; a liquid injection valve opening step, opening the liquid injection valve; a compressor starting step, starting the compressor and operating it according to the specified mode; and a liquid injection valve closing step, closing the liquid injection valve when specified closing conditions are met.

[0007] Among the optional technical solutions, the specified mode is the heating mode.

[0008] In the optional technical solution, the shutdown condition is specified as a specified time N elapsed after the compressor startup step is executed.

[0009] In the optional technical solution, the shutdown condition is specified as follows: after the compressor startup step is executed, the specified heating temperature is reached.

[0010] In the optional technical solution, a standby operation step is also included, in which the compressor stops when the heating temperature set in the heating mode is reached, the main heat valve and the liquid injection valve remain closed, and the hot gas valve remains open.

[0011] The optional technical solution also includes a compressor restart step, in which the compressor restarts when the temperature drops below the set heating temperature in the heating mode, exiting the standby operation mode.

[0012] In optional technical solutions, the air conditioning system also includes a compressor suction pressure regulating valve, which is located between the compressor inlet and the evaporator outlet.

[0013] Another aspect of this application provides a control device for an air conditioning system, comprising: an air conditioning system setting mode determination module for determining whether the air conditioning system is set to a specified mode; a hot gas valve opening command generation module for generating and issuing a command to open the hot gas valve; a main hot gas valve closing command generation module for issuing a command to close the main hot gas valve based on the determination result of the air conditioning system setting mode determination module; a liquid injection valve opening command generation module for generating and issuing a command to open the liquid injection valve; a compressor start module for starting the compressor and operating it according to the specified mode; and a liquid injection valve closing command generation module for generating and issuing a command to close the liquid injection valve when specified closing conditions are met.

[0014] Another aspect of this application provides an air conditioning system, including a memory and a control device, wherein the control device executes the control method of the air conditioning system described above. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of an air conditioning system with an FCV device in one embodiment of this application.

[0016] Figure 2 This is a schematic diagram illustrating the execution steps of a control method for an air conditioning system in one embodiment of this application.

[0017] Figure 3 This is a schematic diagram illustrating the execution steps of a control method for an air conditioning system in one embodiment of this application.

[0018] Figure 4 This is a schematic diagram of an air conditioning system with an FCV device in one embodiment of this application.

[0019] Figure 5 This is a schematic diagram of the control device module of an air conditioning system in one embodiment of this application.

[0020] Reference numerals: 1. Compressor; 2. Main heat valve; 3. Condenser; 4. Receiver; 5. Expansion valve; 6. Evaporator; 7. Hot gas valve; 8. Liquid injection valve; 9. Compressor suction pressure regulating valve; 101. Air conditioning system setting mode judgment module; 102. Hot gas valve opening command generation module; 103. Main heat valve closing command generation module; 104. Liquid injection valve opening command generation module; 105. Compressor start module; 106. Liquid injection valve closing command generation module. Detailed Implementation

[0021] It should be noted that the following will use examples to illustrate the working principle, features and advantages of the refrigeration equipment according to this application. However, it should be understood that all descriptions are given for illustrative purposes only and should not be construed as limiting the application in any way.

[0022] Furthermore, for any single technical feature described or implied in the embodiments mentioned herein, or any single technical feature shown or implied in the various figures, this application still allows for any combination or deletion of these technical features (or their equivalents) without any technical obstacle, thereby obtaining more other embodiments of this application that may not be directly mentioned herein.

[0023] <First Implementation Method>

[0024] Figure 1 This is a schematic diagram of an air conditioning system with an FCV (Flow Control Valve) device according to one embodiment of this application, as shown below. Figure 1 As shown, an air conditioning system equipped with an FCV device includes: compressor 1, main heat valve 2, condenser 3, liquid receiver 4, expansion valve 5, evaporator 6, hot gas valve 7, and liquid injection valve 8. The FCV device (Flow control valve) mainly consists of the main heat valve 2, expansion valve 5, hot gas valve 7, and liquid injection valve 8.

[0025] like Figure 1 As shown, compressor 1, main heat valve 2, condenser 3, liquid receiver 4, expansion valve 5, and evaporator 6 are connected sequentially by refrigerant pipes to form a refrigerant circulation loop. Hot gas valve 7 is connected at one end to the outlet of compressor 1 and at the other end to the inlet of evaporator 6. Liquid injection valve 8 is connected at one end to the outlet of evaporator 6 and at the other end to liquid receiver 4.

[0026] Figure 2 for Figure 1 The diagram shows the execution steps of the control method for the air conditioning system. (See attached diagram.) Figure 2 As shown, the control method of the air conditioning system involved in this embodiment includes: air conditioning system setting mode determination step S1; hot gas valve opening step S2; main hot valve closing step S3; liquid injection valve opening step S4; compressor starting step S5; and liquid injection valve closing step S6.

[0027] In this embodiment, when the air conditioning system receives a start-up command, it executes the air conditioning system setting mode judgment step S1 to determine whether the air conditioning system is set to the specified mode. If the air conditioning system is set to the specified mode, it executes the hot gas valve opening step S2 to open the hot gas valve 7, and simultaneously executes the main hot valve closing step S3 and the liquid injection valve opening step S4 to close the main hot valve 2 and open the liquid injection valve 8. After completing the valve opening and closing operations executed in the hot gas valve opening step S2, the main hot valve closing step S3, and the liquid injection valve opening step S4, it executes the compressor start-up step S5 to control the compressor 1 to start operating according to the specified mode. At this time, the main hot valve 2 is in the closed state, and the hot gas valve 7 is in the open state. After the compressor 1 starts operating according to the specified mode, the refrigerant flows out of the compressor 1 outlet, passes through the hot gas valve 7, and flows into the evaporator 6, where it exchanges heat with the air. After heat exchange, part of the refrigerant flowing out of the evaporator 6 flows into the compressor 1, and the other part flows through the liquid injection valve 8 into the liquid receiver 4 and is stored in the liquid receiver 4. When the air conditioning system meets the specified shutdown conditions, execute step S6 to close the liquid injection valve and close the liquid injection valve 8.

[0028] Specifically, when the air conditioning system is set to the designated mode, because the main heat valve 2 is closed, the refrigerant flowing out of the compressor 1 outlet cannot flow into the condenser 3. Instead, it flows directly into the evaporator 6 through the hot gas valve 7, which connects to the compressor 1 outlet at one end and the evaporator 6 inlet at the other, forming a triangular circulation. The evaporator 6 serves only as a heat exchanger for heat exchange with the outside environment, and the refrigerant no longer passes through the condenser to condense. When the air conditioning system operates in this mode, the compressor 1 performs work to heat the refrigerant. The heated refrigerant then flows through the hot gas valve 7 to the evaporator 6, where it exchanges heat with the outside air, raising the outside air temperature. This heated air can then be used to provide heating for, for example, vans or any other indoor spaces requiring temperature regulation. Part of the cooled refrigerant flowing out of the evaporator 6 flows through the liquid injection valve 8 into and is stored in the receiver 4. The other part is transported to the compressor 1 through the refrigerant circulation loop, where it is heated and pressurized to continue the heating cycle. Furthermore, when the air conditioning system operates to the point where the specified shutdown conditions are met, step S6 is executed to close the liquid injection valve 8, thereby preventing the refrigerant at the outlet of the evaporator 6 from flowing into the receiver 4 through the liquid injection valve 8.

[0029] In this way, when the air conditioning system switches to heating mode and the indoor heat load is low, by controlling the opening of the hot gas valve 7 and the liquid injection valve 8, and the closing of the main hot valve 2, the compressor 1 is turned on. This allows the air conditioning system to operate in heating mode while some refrigerant flows through the hot gas valve 7 and the liquid injection valve 8 into and is stored in the receiver 4. This reduces the refrigerant flow in the refrigerant circulation pipeline, achieving energy savings to accommodate lower indoor heat loads. When the air conditioning system reaches the specified shutdown conditions (e.g., when the indoor temperature setting is reached or any other pre-set shutdown conditions are met), the liquid injection valve 8 is closed. At this time, the refrigerant flowing from the evaporator 6 no longer flows through the liquid injection valve 8 to the receiver 4, but instead all enters the compressor 1 for a triangular heating cycle. This avoids the problem of continuously decreasing refrigerant participating in heating when the liquid injection valve 8 remains open, thus preventing a decrease in heating capacity.

[0030] In a preferred embodiment of this application, in step S6 of closing the liquid injection valve, the closing condition is specified as a predetermined time N elapsed after step S5 of starting the compressor.

[0031] Specifically, when the air conditioning system switches to heating mode, the hot gas valve 7 opens, the main hot valve 2 closes, and the liquid injection valve 8 opens. After executing the compressor start step S5 and a specified time N, such as 10 minutes, the liquid injection valve close step S6 is executed, controlling the liquid injection valve 8 to close.

[0032] In the manner described above, within a specified time N after the compressor starts step S5, some refrigerant will flow into and be stored in the receiver 4 through the liquid injection valve 8. After the air conditioning system has been running for the specified time N, the liquid injection valve is closed step S6, that is, the liquid injection valve 8 is closed, and the refrigerant flowing out of the evaporator 6 is no longer allowed to flow into the receiver 4 through the liquid injection valve 8. This ensures that there is enough refrigerant in the heating triangle cycle composed of the compressor 1, evaporator 6, and hot gas valve 7 for heating cycle, and avoids the problem of the air conditioning system's heating capacity decreasing due to the continuous reduction of refrigerant participating in the heating cycle during the operation of the air conditioning system in heating mode, which would affect the indoor thermal environment.

[0033] In a preferred embodiment of this application, in step S6 of closing the liquid injection valve, the closing condition is defined as reaching a specified heating temperature after step S5 of starting the compressor is executed.

[0034] When the air conditioning system switches to heating mode, the hot gas valve 7 opens, the main hot valve 2 closes, and the liquid injection valve 8 opens. After executing the compressor start step S5, when the indoor ambient temperature reaches the set temperature of the air conditioning system, the liquid injection valve close step S6 is executed, controlling the liquid injection valve 8 to close.

[0035] Specifically, for example, the preset closing condition is that 10 minutes must pass after executing the compressor start step S5 before executing the liquid injection valve closing step S6. However, even if the indoor ambient temperature only reaches the air conditioning system's set temperature 15 minutes after compressor 1 starts during actual operation, the liquid injection valve closing step S6 will still be executed preferentially after a specified time N (e.g., 10 minutes) after executing compressor start step S5, controlling the liquid injection valve 8 to close. That is, if a specified time N passes after executing compressor start step S5, regardless of whether the indoor ambient temperature reaches the air conditioning system's set temperature, the liquid injection valve 8 will be closed to avoid excessive reduction of refrigerant participating in the heating cycle, thus reducing the air conditioning system's heating capacity. The air conditioning system's set temperature can then be reached by continuing to provide heating for a period of time in the subsequent heating triangle cycle composed of compressor 1, evaporator 6, and hot gas valve 7.

[0036] On the other hand, if the air conditioning system detects that the indoor ambient temperature reaches the set temperature of the air conditioning system less than 10 minutes after executing the compressor start-up step S5 (for example, 5 minutes later), then the liquid injection valve closing step S6 will be executed directly after 5 minutes of executing the compressor start-up step S5, controlling the liquid injection valve 8 to close. That is, if the indoor ambient temperature is reached before the specified time N has elapsed, the liquid injection valve 8 will also be controlled to close. At this time, because the indoor ambient temperature has already reached the set temperature, it is necessary to control the continuous reduction of refrigerant in a timely manner to ensure the appropriate heating capacity of the air conditioning system in the later stages.

[0037] In the above manner, after the air conditioning system executes the compressor start-up step S5, the opening time of the liquid injection valve 8 is controlled by comprehensively considering two factors: the indoor ambient temperature and whether the air conditioning system is running in heating mode for a specified time N. This accurately controls the refrigerant flow rate in the refrigerant circulation pipeline participating in the heating cycle, achieving energy saving while ensuring the heating capacity of the air conditioning system. That is, based on different indoor and outdoor environmental parameters, the air conditioning system operating parameters are comprehensively controlled to ensure the refrigerant flow rate participating in the heating cycle, thus ensuring the operating capacity of the air conditioning system while ensuring the indoor thermal environment.

[0038] Although this embodiment uses a specified time N of 10 minutes as an example for illustration, this application is not limited to this. The setting of the specified time N can be flexibly adjusted through prior experiments or calculations based on outdoor environmental parameters, indoor temperature, and the model parameters of the air conditioning system itself in different regions, and all such adjustments should be included within the scope of protection of this application.

[0039] Furthermore, although in this embodiment, the predetermined closing condition of the liquid injection valve 8 is that a predetermined time N or a predetermined heating temperature is reached after the compressor start-up step S5 is executed, this application is not limited to this. Different forms of predetermined closing conditions for the liquid injection valve 8 may be set according to different models of air conditioning systems, operating modes, etc., and all of these should be included within the scope of protection of this application.

[0040] <Second Implementation Method>

[0041] The control method of the air conditioning system in the second embodiment of this application is the same as the control method of the air conditioning system in the above-mentioned embodiments of this application. All methods using the same name or symbols are identical and will not be described again here.

[0042] Figure 3 This is a schematic diagram illustrating the execution steps of a control method for an air conditioning system in one embodiment of this application. (See attached diagram.) Figure 3 As shown, the control method of the air conditioning system provided in the second embodiment of this application differs from the control method of the air conditioning system provided in the first embodiment in that the second embodiment of this application further includes: a standby operation step S7, in which the compressor 1 stops running when the heating temperature set in the heating mode is reached, the main heat valve 2 and the liquid injection valve 8 remain closed, and the hot gas valve 7 remains open.

[0043] After the air conditioning system operates in heating mode for a period of time, when the indoor ambient temperature is detected to have reached the heating temperature set in the heating mode, the standby operation step S7 is executed, controlling the air conditioning system to enter standby operation mode. Specifically, at this time, the compressor 1 stops running, the main heat valve 2 and the liquid injection valve 8 remain closed, and the hot gas valve 7 remains open. More specifically, if the indoor ambient temperature does not reach the heating temperature set in the heating mode within a specified time N after the air conditioning system switches to heating mode, then when the air conditioning system has run for the specified time N, the liquid injection valve closing step S6 is executed, controlling the liquid injection valve 8 to close. At this time, the compressor 1 continues to run, and the refrigerant flowing from the evaporator 6 no longer flows into the receiver 4 through the liquid injection valve 8, but instead flows entirely into the compressor 1 to continue the heating cycle. When the indoor ambient temperature reaches the heating temperature set in the heating mode, the standby operation step S7 is executed, that is, the compressor 1 is controlled to stop running, the main heat valve 2 and the liquid injection valve 8 remain closed, and the hot gas valve 7 remains open.

[0044] If the indoor ambient temperature has reached the set heating temperature before the specified time N after the air conditioning system switches to heating mode, the specified time N will not be continued. Instead, the liquid injection valve closing step S6 and the standby operation step S7 will be executed directly, switching the liquid injection valve 8 to the closed state and controlling the air conditioning system to enter the standby operation mode, and the compressor 1 will stop running.

[0045] Through the above implementation method, when the indoor ambient temperature reaches the heating temperature set in the heating mode after the air conditioning system has been running for a period of time, the air conditioning system is controlled to enter the standby mode. At this time, the liquid injection valve 8 and the main heat valve 2 are closed, and the hot gas valve 7 is opened. After the air conditioning system switches to the heating mode, the refrigerant flowing into the liquid receiver 4 is still stored in the liquid receiver 4. This avoids the problem in the prior art where, when the air conditioning system enters the standby mode, the hot gas valve 7 is closed and the main heat valve 2 is opened, causing the refrigerant to transfer to the condenser. When the compressor 1 needs to be restarted for heating later, the refrigerant in the refrigerant circulation pipeline is insufficient, resulting in a decrease in the heating capacity of the air conditioning system.

[0046] In a preferred embodiment of this application, when the air conditioning system enters standby mode and detects that the indoor temperature is lower than the heating temperature set in the heating mode, the compressor restart step S8 is executed to control the compressor 1 to start again and exit the standby mode. At this time, the main heat valve 2 and the liquid injection valve 8 remain closed, while the hot gas valve 7 remains open.

[0047] Through the above implementation method, when the air conditioning system exits standby mode and re-enters heating mode, the refrigerant flow rate participating in the heating cycle remains the same as the refrigerant flow rate that participated in the heating cycle when switching from any mode other than standby mode to heating mode for the first time. This achieves energy saving while ensuring that there is still enough refrigerant participating in the cooling cycle, reducing the possibility of insufficient refrigerant participating in the heating cycle leading to a decrease in the heating capacity of the air conditioning system. It also avoids the problem of reducing the operating efficiency of the air conditioning system by adjusting the refrigerant flow rate participating in the heating cycle every time it enters or exits standby mode.

[0048] <Third Implementation Method>

[0049] The control method of the air conditioning system in the third embodiment of this application is the same as the control method of the air conditioning system in the above-mentioned embodiments of this application, and all those described using the same names or symbols are the same content, and will not be repeated here.

[0050] Figure 4 This is a schematic diagram of an air conditioning system with an FCV device in one embodiment of this application, as shown below. Figure 4 As shown, the control method of the air conditioning system provided in the third embodiment of this application differs from the control methods of the air conditioning system provided in the first and second embodiments in that the air conditioning system using the control method of the air conditioning system in the third embodiment of this application further includes a compressor suction pressure regulating valve 9 disposed between the compressor 1 inlet and the evaporator 6 outlet.

[0051] When the air conditioning system switches to heating mode, adjusting the opening of the compressor suction pressure regulating valve 9 can change the refrigerant flow rate into the compressor 1. By reducing the refrigerant flow rate into the compressor 1 and changing the pressure at the compressor 1 inlet and the compressor suction pressure regulating valve 9, a portion of the refrigerant flowing out from the evaporator 6 can be regulated by the opening of the compressor suction pressure regulating valve 9 and flow into the receiver 4 through the liquid injection valve 8. Thus, the refrigerant flow rate participating in the heating cycle can be flexibly adjusted according to the operating conditions of the compressor 1.

[0052] By adding a compressor suction pressure regulating valve 9 located between the compressor inlet 1 and the evaporator 6 outlet, the flow rate of refrigerant flowing from the evaporator 6 into the compressor 1 can be more flexibly adjusted according to indoor and outdoor environmental parameters. This, in turn, controls the flow rate of refrigerant flowing into the receiver 4 through the liquid injection valve 8. In other words, the flow rate of the refrigerant can be regulated by adjusting the opening of both the compressor suction pressure regulating valve 9 and the liquid injection valve 8. This ensures that the air conditioning system reaches the set temperature as quickly as possible after switching to heating mode, while also ensuring that the heating capacity of the air conditioning system is appropriately controlled.

[0053] <Fourth Implementation Method>

[0054] The fourth embodiment of this application provides a control device for an air conditioning system. In this embodiment, the control methods of the air conditioning system described with the same names or symbols as those in the above embodiments of this application are all the same content and will not be repeated here.

[0055] Figure 5 This is a schematic diagram of the control device module of an air conditioning system in one embodiment of this application, as shown below. Figure 5 As shown, the control device of the air conditioning system involved in this embodiment includes: an air conditioning system setting mode judgment module 101, a hot gas valve opening command generation module 102, a main hot valve closing command generation module 103, a liquid injection valve opening command generation module 104, a compressor start module 105, and a liquid injection valve closing command generation module 106.

[0056] In this embodiment, when the air conditioning system is turned on, the air conditioning system setting mode judgment module 101 executes the air conditioning system setting mode judgment step S1 to determine whether the air conditioning system is set to the specified mode. If the air conditioning system is set to the specified mode, the hot gas valve opening command generation module 102 executes the hot gas valve opening step S2 to generate and output a hot gas valve opening command to open the hot gas valve 7. At the same time, the main hot gas valve closing command generation module 103 executes the main hot gas valve closing step S3 to generate and output a main hot gas valve closing command, and the liquid injection valve opening command generation module 104 executes the liquid injection valve opening step S4 to generate and output a liquid injection valve opening command, thereby closing the main hot gas valve 2 and the liquid injection valve 8 respectively. After completing the opening and closing of each valve of the hot gas valve 7, the main hot gas valve 2, and the liquid injection valve 8, the compressor start module 105 executes the compressor start step S5 to control the compressor 1 to start and run according to the specified mode. At this time, the main hot gas valve 2 is in the closed state, and the hot gas valve 7 is in the open state.

[0057] After compressor 1 starts operating according to the specified mode, refrigerant flows out of compressor 1, passes through hot gas valve 7, and flows into evaporator 6, where it exchanges heat with the air. After heat exchange, part of the refrigerant flowing out of evaporator 6 flows back into compressor 1, and the other part flows through liquid injection valve 8 into receiver 4 and is stored in receiver 4. When the air conditioning system meets the specified shutdown conditions, liquid injection valve shutdown command generation module 106 executes liquid injection valve shutdown step S6, generates liquid injection valve shutdown command and outputs it, closing liquid injection valve 8.

[0058] Specifically, in this embodiment, the air conditioning system setting mode determination module 101 controls the execution of the air conditioning system setting mode determination step S1 in any one of the first to third embodiments; similarly, the hot gas valve opening command generation module 102 controls the execution of the hot gas valve opening step S2; the main hot valve closing command generation module 103 controls the execution of the main hot valve closing step S3; the liquid injection valve opening command generation module 104 controls the execution of the liquid injection valve opening step S4; the compressor start module 105 controls the execution of the compressor start step S5; and the liquid injection valve closing command generation module 106 controls the execution of the liquid injection valve closing step S6.

[0059] In this application embodiment, an air conditioning system with a memory and a controller is also provided, wherein the control device executes any of the above-described air conditioning system control methods.

[0060] The above are merely preferred embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A control method for an air conditioning system, the air conditioning system comprising a compressor, a main heat valve, a condenser, a liquid receiver, an expansion valve, and an evaporator connected in sequence to form a refrigerant circulation loop, and a hot gas valve connected at one end to the compressor outlet and the other end to the evaporator inlet, and a liquid injection valve connected at one end to the evaporator outlet and the other end to the liquid receiver, characterized in that, include, The air conditioning system setting mode determination step determines whether the air conditioning system is set to a specified mode. Hot gas valve opening step: Open the hot gas valve; The main heat valve closing step involves closing the main heat valve based on the judgment result of the air conditioning system setting mode judgment step. The liquid injection valve opening step involves opening the liquid injection valve. The compressor startup procedure involves starting the compressor and operating it according to the specified mode. The procedure for closing the liquid injection valve is as follows: when the specified closing conditions are met, the liquid injection valve is closed.

2. The control method for the air conditioning system as described in claim 1, characterized in that, The specified mode is the heating mode.

3. The control method for the air conditioning system as described in claim 2, characterized in that, The specified shutdown condition is that a specified time N has elapsed after the compressor start-up step is executed.

4. The control method for the air conditioning system as described in claim 2, characterized in that, The specified shutdown condition is that after the compressor start-up step is executed, the specified heating temperature is reached.

5. The control method for the air conditioning system as described in claim 3 or 4, characterized in that, It also includes, During standby operation, when the heating temperature set in the heating mode is reached, the compressor stops, the main heat valve and the liquid injection valve remain closed, and the hot gas valve remains open.

6. The control method for an air conditioning system as described in claim 5, characterized in that, In the compressor restart step, when the temperature drops below the set heating temperature of the heating mode, the compressor restarts and exits the standby mode.

7. The control method for the air conditioning system as described in claim 6, characterized in that, The air conditioning system also includes a compressor suction pressure regulating valve, which is located between the compressor inlet and the evaporator outlet.

8. A control device for an air conditioning system, characterized in that, include, An air conditioning system setting mode determination module determines whether the air conditioning system is set to a specified mode. The hot gas valve opening command generation module generates and issues a command to open the hot gas valve; The main heat valve closing command generation module issues a command to close the main heat valve based on the judgment result of the air conditioning system setting mode judgment module. The liquid injection valve opening command generation module generates and issues a command to open the liquid injection valve; Start the compressor module, start the compressor, and operate it according to the specified mode; The liquid injection valve closing command generation module generates and issues a command to close the liquid injection valve when the specified closing conditions are met.

9. An air conditioning system, comprising a memory and a controller, characterized in that, The controller performs the control method of the air conditioning system as described in any one of claims 1-7.

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