Heat pump air conditioning system and control method and device of heat pump air conditioning system

Abstract

The invention provides a heat pump air conditioning system and a control method and device of the heat pump air conditioning system. The heat pump air conditioning system comprises a compressor, an indoor heat exchanger and an outdoor heat exchanger which are communicated through a refrigerant pipeline; an outlet of the indoor heat exchanger communicates with an injection liquid inlet of the injector and an inlet of the outdoor heat exchanger, an outlet of the outdoor heat exchanger communicates with an injection air suction port of the injector, and a two-way valve is arranged at the injection liquid inlet of the injector; a feeding hole of the gas-liquid separator is communicated with an ejection liquid outlet of the ejector, and a liquid outlet of the gas-liquid separator is communicated to an inlet of the outdoor heat exchanger. According to the system, ultralow-temperature heating can be achieved with low cost on the basis of existing hardware. In addition, liquid saturation supercooling and air suction saturation superheating can be achieved, the refrigerant density of the compressor in the air suction state is improved, the air displacement of the compressor is increased, the heating capacity is improved, and therefore the output power and the energy efficiency ratio of the heat pump unit are improved.

Description

Technical Field

[0001] The present invention relates to the field of electrical equipment technology, and in particular to a heat pump air-conditioning system, and a control method and a control device for the heat pump air-conditioning system. Background Art

[0002] In the related technology, the existing air-to-air heat pump technology can achieve -30℃ ambient temperature heating, but when the outdoor ambient temperature drops further, the compressor cannot provide a sufficient compression ratio to support the evaporation-condensation pressure difference, and cannot achieve both high-temperature water outlet and ultra-low ambient temperature. The use of two-stage compression or the development of a new high-pressure ratio compressor is costly.

[0003] A similar solution is the two-stage compression solution, that is, under the premise that one compressor cannot achieve a high compression ratio, two compressors are used to perform compression in relay, with the first-stage compressor achieving ultra-low-pressure suction, and the exhaust of the first-stage compressor enters the suction of the second-stage compressor, which is then compressed by the second-stage compressor to achieve ultra-high-pressure exhaust, thereby achieving an ultra-high compression ratio. The disadvantages of this solution are that the system is relatively complex, the hardware cost is relatively high, and the power consumption of the two compressors is relatively high. Summary of the invention

[0004] The present invention provides a heat pump air conditioning system, a control method and a control device for the heat pump air conditioning system, which are used to solve the defects in the prior art and achieve the following technical effects: ultra-low temperature heating is achieved at a relatively low cost based on the existing hardware. In addition, liquid saturation supercooling and suction saturation superheating can be achieved, the refrigerant density in the suction state of the compressor can be increased, the compressor exhaust volume can be increased, the heating capacity can be increased, and thus the output power and energy efficiency ratio of the heat pump unit can be improved.

[0005] A heat pump air conditioning system according to a first embodiment of the present invention comprises:

[0006] A compressor, an indoor heat exchanger and an outdoor heat exchanger connected by a refrigerant pipeline;

[0007] An ejector, the outlet of the indoor heat exchanger is respectively connected to the ejector liquid inlet of the ejector and the inlet of the outdoor heat exchanger, the outlet of the outdoor heat exchanger is connected to the ejector air suction port of the ejector, and a two-way valve is provided at the ejector liquid inlet of the ejector;

[0008] A gas-liquid separator, wherein the feed port thereof is connected to the ejection liquid outlet of the ejector, and the liquid outlet of the gas-liquid separator is connected to the inlet of the outdoor heat exchanger.

[0009] According to one embodiment of the present invention, the heat pump air conditioning system further includes:

[0010] An enthalpy-increasing pipeline, the enthalpy-increasing pipeline is arranged between the indoor heat exchanger and the outdoor heat exchanger and is connected to the return air port of the compressor;

[0011] The enthalpy-increasing pipeline is provided with an enthalpy-increasing expansion valve and an enthalpy-increasing heat exchanger, and the refrigerant pipeline between the indoor heat exchanger and the outdoor heat exchanger flows through the enthalpy-increasing heat exchanger.

[0012] According to one embodiment of the present invention, a first expansion valve and a second expansion valve are provided between the indoor heat exchanger and the outdoor heat exchanger, the first expansion valve and the second expansion valve are respectively located upstream and downstream of the enthalpy increasing pipeline, and the first expansion valve is connected in parallel with a first check valve, and the second expansion valve is connected in parallel with a second check valve;

[0013] The flow direction of the first check valve is oriented in a direction from the indoor heat exchanger to the outdoor heat exchanger, and the flow direction of the second check valve is opposite to the flow direction of the first check valve.

[0014] According to one embodiment of the present invention, a third check valve and a capillary tube are provided between the liquid outlet of the gas-liquid separator and the inlet of the outdoor heat exchanger, and the flow direction of the third check valve is oriented along the direction from the liquid outlet of the gas-liquid separator to the inlet of the outdoor heat exchanger.

[0015] According to one embodiment of the present invention, a gas-liquid separation chamber is formed inside the gas-liquid separator;

[0016] A gas-liquid inlet pipe is provided at one end of the gas-liquid separator and a liquid outlet pipe is provided at the other end. The gas-liquid inlet pipe and the liquid outlet pipe are both connected to the gas-liquid separation chamber and form a feed port and a liquid outlet, respectively. The gas-liquid inlet pipe and the liquid outlet pipe are both connected to the side wall of the gas-liquid separator and are respectively arranged along the tangent direction of the side wall of the gas-liquid separator.

[0017] According to a second aspect of the present invention, a control method for a heat pump air conditioning system based on the first aspect of the present invention comprises:

[0018] Obtaining the current working mode of the heat pump air conditioning system;

[0019] Receiving a signal that the heat pump air conditioning system is in heating mode, obtaining the outdoor ambient temperature and the compressor speed;

[0020] An execution logic is generated according to the outdoor ambient temperature and the compressor speed, and the opening or closing of the two-way valve is controlled according to the execution logic.

[0021] According to an embodiment of the present invention, the step of generating an execution logic according to the outdoor ambient temperature and the compressor speed, and controlling the opening or closing of the two-way valve according to the execution logic specifically includes:

[0022] Determining that the outdoor ambient temperature is lower than a first set temperature and the compressor speed is higher than a first set speed, controlling the two-way valve to open so that the heat pump air conditioning system enters an ejection mode;

[0023] After the injection mode continues for a set time, it is determined that the outdoor ambient temperature is higher than the first set temperature and the compressor speed is lower than the second set speed, and the two-way valve is controlled to close so that the heat pump air-conditioning system exits the injection mode.

[0024] According to one embodiment of the present invention, the control method of the heat pump air conditioning system further includes:

[0025] It is determined that the outdoor ambient temperature is lower than a second set temperature, and the enthalpy-increasing expansion valve is controlled to open so that the heat pump air-conditioning system performs an enthalpy-increasing operation, wherein the second set temperature is greater than the first set temperature.

[0026] According to one embodiment of the present invention, the control method of the heat pump air conditioning system further includes:

[0027] In the ejection mode, the first expansion valve and the second expansion valve are both controlled to be closed.

[0028] According to a third aspect of the present invention, a control device for a heat pump air conditioning system based on the first aspect of the present invention comprises:

[0029] A first acquisition module, used to acquire the current working mode of the heat pump air-conditioning system;

[0030] A second acquisition module is used to receive a signal that the heat pump air-conditioning system is in a heating mode, and acquire an outdoor ambient temperature and a compressor speed;

[0031] A control module is used to generate an execution logic according to the outdoor ambient temperature and the compressor speed, and control the opening or closing of the two-way valve according to the execution logic.

[0032] In order to realize ultra-low temperature heating of a heat pump air conditioning system under a single-stage compressor structure, the present invention proposes a heat pump air conditioning system, which uses the Venturi effect and an ejector to further reduce the evaporation pressure under the premise of using a single-stage compressor structure and without changing the compression ratio of the compressor, and uses a gas-liquid separator to realize the recycling of the ejected fluid and the separation of the compressor suction gas and liquid, so as to realize ultra-low temperature heating at a lower cost on the basis of existing hardware. In addition, the structure of the ejector combined with the gas-liquid separator in the present invention can realize liquid saturation supercooling and suction saturation superheating, increase the refrigerant density in the compressor suction state, increase the compressor exhaust volume, and increase the heating capacity, thereby improving the output power and energy efficiency ratio of the heat pump unit.

[0033] It needs to be explained that after the introduction of the ejector structure, the refrigerant liquid flowing through the evaporator comes from the liquid refrigerant at the separation point in the gas-liquid separator. Therefore, the evaporator and the pipes on both sides of it belong to the low-pressure side compared to the main refrigerant pipe of the system. In addition, because the ejector forms a negative pressure at the air intake port to adsorb the gaseous refrigerant flowing out of the evaporator, the evaporation pressure of the evaporator will be further reduced, that is, the ejector can further reduce the evaporation pressure. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0035] Figure 1 It is a structural schematic diagram of the heat pump air conditioning system provided by the present invention;

[0036] Figure 2 It is a structural schematic diagram of the heat pump air conditioning system provided by the present invention in a low-load output mode when the outdoor ambient temperature is relatively high;

[0037] Figure 3 It is a pressure-enthalpy diagram of the heat pump air-conditioning system provided by the present invention in a low-load output mode with a high outdoor ambient temperature;

[0038] Figure 4 It is a structural schematic diagram of a heat pump air conditioning system provided by the present invention in a low enthalpy increase mode in an outdoor environment;

[0039] Figure 5 It is a pressure-enthalpy diagram of the heat pump air-conditioning system provided by the present invention in a relatively low enthalpy increase mode in an outdoor environment;

[0040] Figure 6 It is a structural schematic diagram of the heat pump air conditioning system provided by the present invention in an outdoor ultra-low temperature enthalpy increase + induced emission mode;

[0041] Figure 7 It is a pressure-enthalpy diagram of the heat pump air-conditioning system provided by the present invention in an outdoor ultra-low temperature enthalpy increase + induced mode;

[0042] Figure 8 It is a schematic diagram of the steps of the control method of the heat pump air conditioning system provided by the present invention;

[0043] Fig. 9 It is a structural schematic diagram of a control device for a heat pump air conditioning system provided by the present invention;

[0044] Fig.10 It is a structural schematic diagram of the electronic device provided by the present invention.

[0045] Reference numerals:

[0046] 01. Compressor; 02. Indoor heat exchanger; 03. Outdoor heat exchanger; 04. Liquid storage tank;

[0047] 05, ejector; 51, ejector liquid inlet; 52, ejector air intake; 53, ejector liquid outlet; 54, two-way valve; 06, gas-liquid separator; 07, four-way valve;

[0048] 81. Enthalpy-increasing pipeline; 82. Enthalpy-increasing expansion valve; 83. Enthalpy-increasing heat exchanger; 91. First expansion valve; 92. Second expansion valve; 93. First check valve; 94. Second check valve; 95. Third check valve; 96. Capillary tube; 110. First acquisition module; 120. Second acquisition module; 130. Control module. DETAILED DESCRIPTION

[0049] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0050] The following describes a heat pump air-conditioning system, a control method for a heat pump air-conditioning system, and a control device thereof provided by the present invention with reference to the accompanying drawings, wherein the structural basis of the control method and the control device of the present invention is the heat pump air-conditioning system provided in the embodiment of the first aspect of the present invention.

[0051] like Figures 1 to 7 As shown, the heat pump air conditioning system according to the first embodiment of the present invention includes a compressor 01, an indoor heat exchanger 02, an outdoor heat exchanger 03, an ejector 05 and a gas-liquid separator 06.

[0052] The compressor 01, the indoor heat exchanger 02 and the outdoor heat exchanger 03 are interconnected through a refrigerant pipeline. The outlet of the indoor heat exchanger 02 is respectively connected to the ejector liquid inlet 51 of the ejector 05 and the inlet of the outdoor heat exchanger 03, and the outlet of the outdoor heat exchanger 03 is connected to the ejector air intake port 52 of the ejector 05. A two-way valve 54 is provided at the ejector liquid inlet 51 of the ejector 05.

[0053] The feed port of the gas-liquid separator 06 is connected to the ejection liquid outlet 53 of the ejector 05 , and the liquid outlet of the gas-liquid separator 06 is connected to the inlet of the outdoor heat exchanger 03 , and the gas outlet of the gas-liquid separator 06 is connected to the air intake port of the compressor 01 .

[0054] The specific working principle of the heat pump air conditioning system according to the embodiment of the present invention is as follows: when the outdoor ambient temperature is ultra-low temperature, the compressor 01 cannot provide a sufficient compression ratio to support the evaporation-condensation pressure difference. Therefore, the heat pump air conditioning system enters the ejection mode by opening the two-way valve 54 at the liquid inlet of the ejector 05. In the ejection mode, the gaseous refrigerant flows out from the exhaust port of the compressor 01, passes through the four-way valve 07 and enters the indoor heat exchanger 02 for condensation and heat release. The liquid refrigerant generated after condensation enters the ejector 05 through the ejection liquid inlet 51 of the ejector 05. The liquid refrigerant is ejected in the ejector 05. Under the action of the Venturi effect, a negative pressure suction is formed inside the ejector 05. At this time, the ejector 05 uses the ejection suction port 52 to extract the outdoor heat exchanger 03 (i.e., the evaporator) Gaseous refrigerant is sucked in, and the saturated refrigerant liquid injected at high speed is mixed with the gaseous refrigerant from the evaporator and enters the feed port of the gas-liquid separator 06 through the four-way valve 07. In this process, the saturated liquid refrigerant and the gaseous refrigerant are fully mixed and exchanged with each other in the ejector 05, the pipeline, and the gas-liquid separator 06 so that the overall pressure of the downstream refrigerant increases. Among them, the gaseous part of the refrigerant in the gas-liquid separator 06 returns to the suction port of the compressor 01, and the liquid part enters the outdoor heat exchanger 03 (that is, the evaporator). The liquid refrigerant becomes gaseous refrigerant after evaporation and heat absorption in the evaporator. The gaseous refrigerant flowing out of the evaporator enters the ejector 05 through the suction port of the ejector 05, and passes through the four-way valve 07 and the gas-liquid separator 06 in turn and finally enters the suction port of the compressor 01.

[0055] It should be pointed out that the ejector 05 has an ejection liquid inlet 51, an ejection liquid outlet 53 and an ejection air suction port 52. The working principle of the ejector 05 is as follows: The ejector 05 is also called a Venturi ejector, and its main structure is a Venturi tube, wherein the Venturi tube is manufactured based on the Venturi effect. The principle of the Venturi effect is that when the wind blows over an obstacle, the air pressure near the port above the leeward side of the obstacle is relatively low, thereby generating an adsorption effect and causing air flow. Specifically, the Venturi ejector is to accelerate the gas flow rate by changing the air flow from coarse to fine, so that the gas forms a negative pressure zone on the rear side of the Venturi tube outlet, and the ejection air suction port 52 is formed at the negative pressure zone, thereby adsorbing the gas connected to the ejection air suction port 52.

[0056] It can be understood that in the above-mentioned heat pump air conditioning structure, liquid refrigerant flows in from the injection liquid inlet 51 of the ejector 05 and is ejected out from the injection liquid outlet 53. At this time, a negative pressure zone is formed at the injection air intake port 52 of the ejector 05, which sucks in the gaseous refrigerant flowing out of the evaporator and transports it to the gas-liquid separator 06.

[0057] In the related technology, the existing air-to-air heat pump technology can achieve -30℃ ambient temperature heating, but when the outdoor ambient temperature drops further, the compressor cannot provide a sufficient compression ratio to support the evaporation-condensation pressure difference, and cannot achieve both high-temperature water outlet and ultra-low ambient temperature. The use of two-stage compression or the development of a new high-pressure ratio compressor is costly.

[0058] A similar solution is the two-stage compression solution, that is, under the premise that one compressor cannot achieve a high compression ratio, two compressors are used to perform compression in relay, with the first-stage compressor achieving ultra-low-pressure suction, and the exhaust of the first-stage compressor enters the suction of the second-stage compressor, which is then compressed by the second-stage compressor to achieve ultra-high-pressure exhaust, thereby achieving an ultra-high compression ratio. The disadvantages of this solution are that the system is relatively complex, the hardware cost is relatively high, and the power consumption of the two compressors is relatively high.

[0059] In order to solve the technical problems existing in the above-mentioned related technologies, that is, to realize ultra-low temperature heating of the heat pump air-conditioning system under the structure of a single-stage compressor 01, the present invention proposes a heat pump air-conditioning system, which uses the Venturi effect and uses an ejector 05 to further reduce the evaporation pressure under the premise of using the structure of a single-stage compressor 01 and not changing the compression ratio of the compressor 01, and at the same time uses a gas-liquid separator 06 to realize the recycling of the ejected fluid and the separation of the gas and liquid of the compressor 01 suction, so as to realize ultra-low temperature heating at a relatively low cost on the basis of the existing hardware. In addition, the structure of the ejector 05 and the gas-liquid separator 06 used in combination in the present invention can realize liquid saturation supercooling and suction saturation superheating, increase the refrigerant density in the suction state of the compressor 01, increase the exhaust volume of the compressor 01, and increase the heating capacity, thereby improving the output power and energy efficiency ratio of the heat pump unit.

[0060] It needs to be explained that after the structure of the ejector 05 is introduced, the refrigerant liquid flowing through the evaporator comes from the liquid refrigerant separated in the gas-liquid separator 06. Therefore, the evaporator and the pipes on both sides thereof belong to the low-pressure side compared with the main refrigerant pipe of the system. In addition, because the ejector 05 forms a negative pressure at the air intake port to adsorb the gaseous refrigerant flowing out of the evaporator, the evaporation pressure of the evaporator will be further reduced, that is, the ejector 05 can further reduce the evaporation pressure.

[0061] like Figure 1 As shown, according to some embodiments of the present invention, the heat pump air conditioning system further includes an enthalpy-increasing pipe 81, an enthalpy-increasing expansion valve 82 and an enthalpy-increasing heat exchanger 83. The enthalpy-increasing pipe 81 is provided between the indoor heat exchanger 02 and the outdoor heat exchanger 03 and is connected to the return air port of the compressor 01.

[0062] The enthalpy-increasing pipeline 81 is provided with an enthalpy-increasing expansion valve 82 and an enthalpy-increasing heat exchanger 83 , and the refrigerant pipeline between the indoor heat exchanger 02 and the outdoor heat exchanger 03 flows through the enthalpy-increasing heat exchanger 83 .

[0063] In this way, in the ejection mode, the enthalpy-increasing expansion valve 82 is also opened, so that the heat pump air-conditioning system performs an enthalpy-increasing operation. During this process, the exhaust gas of the compressor 01 enters the condenser through the four-way valve 07, and the condensed liquid refrigerant passes through the enthalpy-increasing heat exchanger 83 to achieve super-supercooling, and is divided into two paths after flowing out of the enthalpy-increasing expansion valve 82. The main path enters the ejector 05 through the electric two-way valve 54, and the auxiliary path passes through the enthalpy-increasing expansion valve 82 and the enthalpy-increasing heat exchanger 83 and then flows back to the enthalpy-increasing intake port of the compressor 01.

[0064] It can be understood that, considering that the ejector 05 needs to be activated in the ultra-low temperature mode, and the ejector 05 has the function of throttling and reducing pressure, therefore, in order to prevent the liquid refrigerant from cooling itself and volatilizing gas during injection, thereby affecting the evaporation and air intake, the liquid before entering the ejector 05 must be in a supercooled state and remain in a gas-free saturated liquid state after injection. Therefore, the enthalpy increase heat exchanger 83 in this system needs to have a very strong heat exchange capacity so that the liquid refrigerant flowing out of the enthalpy increase heat exchanger 83 is super-supercooled.

[0065] like Figure 1 As shown, according to some embodiments of the present invention, a first expansion valve 91 and a second expansion valve 92 are provided between the indoor heat exchanger 02 and the outdoor heat exchanger 03. The first expansion valve 91 and the second expansion valve 92 are respectively located upstream and downstream of the enthalpy increasing pipe 81, and the first expansion valve 91 is connected in parallel with a first check valve 93, and the second expansion valve 92 is connected in parallel with a second check valve 94.

[0066] The flow direction of the first check valve 93 is oriented along the direction from the indoor heat exchanger 02 to the outdoor heat exchanger 03 , and the flow direction of the second check valve 94 is opposite to that of the first check valve 93 .

[0067] In this way, the first check valve 93 and the second check valve 94 are both check valves, and therefore, the check valves can achieve a one-way flow of the refrigerant on the refrigerant pipeline.

[0068] like Figure 1 As shown, according to some embodiments of the present invention, a third check valve 95 and a capillary tube 96 are provided between the liquid outlet of the gas-liquid separator 06 and the inlet of the outdoor heat exchanger 03, and the flow direction of the third check valve 95 is oriented along the direction from the liquid outlet of the gas-liquid separator 06 to the inlet of the outdoor heat exchanger 03.

[0069] In this way, the refrigerant can only flow from the liquid outlet of the gas-liquid separator 06 to the outdoor heat exchanger 03 to achieve evaporation and gasification, thereby preventing the refrigerant from flowing back from the outdoor heat exchanger 03 to the gas-liquid separator 06.

[0070] In addition, the capillary tube 96 can play a role in throttling and boosting pressure, ensuring that the refrigerant flowing into the outdoor heat exchanger 03 has sufficient hydraulic pressure to smoothly complete evaporation and gasification.

[0071] like Figure 1As shown, according to some embodiments of the present invention, a gas-liquid separation chamber is formed inside the gas-liquid separator 06. A gas-liquid inlet pipe is provided at one end of the gas-liquid separator 06 and a liquid outlet pipe is provided at the other end, the gas-liquid inlet pipe and the liquid outlet pipe are both connected to the gas-liquid separation chamber and form a feed port and a liquid outlet, respectively, and the gas-liquid inlet pipe and the liquid outlet pipe are both connected to the side wall of the gas-liquid separator 06 and are respectively arranged along the tangent direction of the side wall of the gas-liquid separator 06.

[0072] The following describes a control method for a heat pump air conditioner according to a second embodiment of the present invention with reference to the accompanying drawings. It should be noted that the control method of the present invention is based on the heat pump air conditioner described above.

[0073] like Figure 8 As shown, a control method of a heat pump air conditioning system according to an embodiment of the present invention includes:

[0074] Step S1, obtaining the current working mode of the heat pump air conditioning system;

[0075] Step S2, receiving a signal indicating that the heat pump air conditioning system is in heating mode, and obtaining the outdoor ambient temperature and the speed of the compressor 01;

[0076] Step S3, generating execution logic according to the outdoor ambient temperature and the rotation speed of the compressor 01, and controlling the opening or closing of the two-way valve 54 according to the execution logic.

[0077] According to the control method of the heat pump air conditioner according to the embodiment of the present invention, when the air conditioner is in the heating mode, if it is determined that the outdoor ambient temperature and the speed of the compressor 01 both meet certain set conditions, it proves that the current environment is in ultra-low temperature heating conditions, and the current performance of the compressor 01 cannot meet the high compression ratio working requirements under ultra-low temperature heating. Therefore, the present invention introduces the ejector 05, and controls the two-way valve 54 to open after the above conditions are met so that the ejector 05 works in the ultra-low temperature heating mode, further reducing the evaporation pressure, realizing ultra-low temperature heating under the single compressor 01 structure, and can realize saturated supercooling of the condensed liquid and saturated superheating of the compressor 01 suction, increase the refrigerant density in the suction state of the compressor 01, increase the exhaust volume of the compressor 01, increase the heating amount, and at the same time reduce the compression ratio, improve the energy efficiency ratio, and realize the improvement of the capacity and energy efficiency of the heat pump unit.

[0078] According to some embodiments of the present invention, the steps of generating execution logic according to the outdoor ambient temperature and the speed of the compressor 01, and controlling the opening or closing of the two-way valve 54 according to the execution logic specifically include:

[0079] Determine that the outdoor ambient temperature is lower than the first set temperature and the speed of the compressor 01 is higher than the first set speed, and control the two-way valve 54 to open so that the heat pump air conditioning system enters the induced mode;

[0080] After the injection mode continues for a set time, it is determined that the outdoor ambient temperature is higher than the first set temperature and the speed of the compressor 01 is lower than the second set speed, and the two-way valve 54 is controlled to close so that the heat pump air-conditioning system exits the injection mode.

[0081] For example, the outdoor ambient temperature and the speed of compressor 01 are used as the judgment logic for starting the ejection cycle, wherein the outdoor ambient temperature is the first trigger condition and the speed of compressor 01 is the second trigger condition. For example, the outdoor ambient temperature is set to be lower than -30°C as a necessary condition for starting the ejection cycle. When the outdoor ambient temperature is higher than -30°C, the ejection cycle is never started. When the outdoor ambient temperature is lower than -30°C, the ejection cycle preparation is started. At this time, the speed of compressor 01 is judged. When the speed of compressor 01 reaches more than 95% of the rated speed, the ejection cycle mode is started. The logic for exiting the ejection cycle mode is: when the outdoor ambient temperature is higher than -30°C and the speed of compressor 01 is lower than 90% at the same time, the ejection mode is exited and the enthalpy increase mode is operated.

[0082] According to some embodiments of the present invention, the control method of the heat pump air conditioning system further includes:

[0083] It is determined that the outdoor ambient temperature is lower than the second set temperature, and the enthalpy-increasing expansion valve 82 is controlled to open so that the heat pump air-conditioning system performs an enthalpy-increasing operation, wherein the second set temperature is greater than the first set temperature.

[0084] According to some embodiments of the present invention, the control method of the heat pump air conditioning system further includes:

[0085] In the ejection mode, the first expansion valve 91 and the second expansion valve 92 are controlled to be closed.

[0086] A specific embodiment of the heat pump air conditioning system and the control method thereof of the present invention will be described below with reference to the accompanying drawings.

[0087] like Figure 1 As shown, the heat pump air conditioning system includes a compressor 01, a four-way valve 07, an outdoor heat exchanger 03, an indoor heat exchanger 02, a liquid storage device 04, an enthalpy increasing device, an ejector 05 and a gas-liquid separator 06. The compressor 01, the indoor heat exchanger 02 and the outdoor heat exchanger 03 are interconnected through a refrigerant pipeline.

[0088] The outlet of the liquid storage tank 04 is connected to the first expansion valve 91 and the first check valve connected in parallel. The refrigerant pipeline subsequently flows through the enthalpy increasing heat exchanger 83 of the enthalpy increasing device to achieve super subcooling of the refrigerant. Then the refrigerant pipeline is divided into two paths. One path passes through the enthalpy increasing pipeline 81 and flows through the enthalpy increasing expansion valve 82 and the enthalpy increasing heat exchanger 83 in turn to finally flow into the air supply port of the compressor 01. The other path is used as the main refrigerant pipeline. The main refrigerant pipeline is divided into two paths. One path is connected to the two-way valve 54. To the injection liquid inlet 51 of the ejector 05, another refrigerant flows into the outdoor heat exchanger 03 through the second check valve and the second expansion valve 92 connected in parallel, the outlet of the outdoor heat exchanger 03 is connected with the injection air intake port 52 of the ejector 05, the feed port of the gas-liquid separator 06 is connected with the injection liquid outlet 53 of the ejector 05, and the liquid outlet of the gas-liquid separator 06 is connected to the inlet of the outdoor heat exchanger 03, and the air outlet of the gas-liquid separator 06 is connected to the air intake port of the compressor 01.

[0089] A third check valve 95 and a capillary tube 96 are provided between the liquid outlet of the gas-liquid separator 06 and the inlet of the outdoor heat exchanger 03 . The flow direction of the third check valve 95 is oriented along the direction from the liquid outlet of the gas-liquid separator 06 to the inlet of the outdoor heat exchanger 03 .

[0090] The gas-liquid separation chamber is a cyclone gas-liquid separator 06, wherein a gas-liquid separation chamber is formed inside the gas-liquid separator 06. A gas-liquid inlet pipe is provided at one end of the gas-liquid separator 06 and a liquid outlet pipe is provided at the other end, the gas-liquid inlet pipe and the liquid outlet pipe are both connected to the gas-liquid separation chamber and form a feed port and a liquid outlet, respectively, and the gas-liquid inlet pipe and the liquid outlet pipe are both connected to the side wall of the gas-liquid separator 06 and are respectively arranged along the tangent direction of the side wall of the gas-liquid separator 06.

[0091] When heating, the heat pump air conditioning system adopts three circulation modes according to different outdoor ambient temperatures and different output heating powers, namely:

[0092] (1) Low load output mode with high outdoor ambient temperature:

[0093] like Figure 2 and Figure 3 As shown, the exhaust gas of compressor 01 (point 2) enters the condenser (i.e., indoor heat exchanger 02) through the four-way valve 07, and the condensed liquid (point 3) enters the liquid storage tank 04, and then enters the enthalpy increasing heat exchanger 83 through the first check valve. At this time, the first expansion valve 91 is in a closed state, and the liquid refrigerant passes through the enthalpy increasing heat exchanger 83 and is throttled by the second expansion valve 92 (point 4) before entering the evaporator (i.e., outdoor heat exchanger 03) to absorb heat. At this time, the second expansion valve 92 and the two-way valve 54 at the inlet of the ejector 05 are in a closed state, and the liquid refrigerant absorbs heat and vaporizes in the evaporator, and the gaseous refrigerant returns to the suction port (point 1) of the compressor 01 through the ejector 05, the four-way valve 07, and the gas-liquid separator 06 to complete the cycle. This cycle is the most conventional air-conditioning refrigeration cycle mode.

[0094] (2) Low enthalpy increase mode in outdoor environment:

[0095] like Figure 4 and Figure 5 As shown, the exhaust gas of compressor 01 (point 4) enters the condenser (i.e., indoor heat exchanger 02) through the four-way valve 07, and the condensed liquid enters the liquid storage tank 04 (point 5), and then enters the enthalpy increasing heat exchanger 83 through the first check valve. At this time, the first expansion valve is in a closed state, and the liquid refrigerant is divided into two paths after passing through the enthalpy increasing heat exchanger 83 (point 6). The main path circulation is the same as the 0℃ working condition flow path, and the auxiliary path enters the enthalpy increasing heat exchanger 83 after throttling and cooling by the enthalpy increasing expansion valve 82 (point 7), absorbs the sensible heat of the liquid refrigerant in the main path, and supercools the liquid refrigerant. The liquid refrigerant in the auxiliary path absorbs heat and vaporizes (point 9) and enters the enthalpy increasing air intake port of compressor 01 to complete the cycle. This cycle is the jet enthalpy increasing cycle mode of a conventional air energy heat pump.

[0096] Considering that the ejector 05 needs to be activated in the ultra-low temperature mode, the ejector 05 is used for throttling and reducing the pressure. In order to prevent the liquid refrigerant from cooling itself and volatilizing gas during injection, thereby affecting the evaporation and air intake, the liquid must be in a supercooled state before entering the ejector 05, and it must still be in a gas-free saturated liquid state after injection. Therefore, the enthalpy increase heat exchanger 83 needs to have a very strong heat exchange capacity, which can make the refrigerant liquid at 6 points super-supercooled.

[0097] (3) Outdoor ultra-low temperature enthalpy increase + induced emission mode:

[0098] like Figure 6 and Figure 7As shown, the exhaust gas of compressor 01 (point 4) enters the condenser (i.e., indoor heat exchanger 02) through the four-way valve 07, and the condensed liquid (point 5) passes through the first check valve and the enthalpy increasing heat exchanger 83 (point 6, super subcooling state) and is divided into two paths. The main path enters the ejector 05 through the two-way valve 54, and the auxiliary path passes through the enthalpy increasing expansion valve 82 (point 7) and then returns to the enthalpy increasing intake port of compressor 01 (point 9) through the enthalpy increasing heat exchanger 83. In this mode, the first expansion valve 91 and the second expansion valve 92 are both in the closed state. The refrigerant is sprayed in the ejector 05 (point 8, since point 6 is in a super-cooled state, point 8 is in a saturated liquid state or a super-cooled liquid state, and there is no gas flash). Under the action of the Venturi effect, negative pressure suction is formed (point 8), and the refrigerant gas (point 12) is sucked from the evaporator (that is, the outdoor heat exchanger 03). The high-speed sprayed saturated refrigerant liquid (point 8) is mixed with the gas from the evaporator (point 12) and enters the gas-liquid separator 06 (point 10) through the four-way valve 07. In this process, the saturated liquid refrigerant and the gas refrigerant are fully mixed and exchanged with each other in the ejector 05, the pipeline, and the liquid storage tank. The pressure rises, and the pressure of the saturated liquid rises to point 10 along the saturation line, and the pressure of the saturated gas (point 12) is increased to point 1 along the saturation line. Point 1 is a saturated gas, and point 1 is a saturated liquid. The pressures of these two points are the same. The gaseous part returns to the suction port of compressor 01, and the liquid part enters the evaporator after throttling through the third check valve and capillary 96 (point 11), and after evaporation and heat absorption (point 12), enters the suction port of compressor 01 (point 1) through ejector 05, four-way valve 07, and gas-liquid separator 06.

[0099] On the pressure-enthalpy diagram, point 10 and point 1 are both located in the gas-liquid separator 06 and are located on the isobaric line. Point 8 and point 12 are located at the injection port of the ejector 05 and are located on the isobaric line.

[0100] It can be understood that in the outdoor ultra-low temperature enthalpy increase + ejection mode, since the exhaust mass flow rate of compressor 01 is equal to the main suction mass flow rate + the enthalpy increase mass flow rate, and the exhaust mass flow rate is equal to the liquid mass flow rate injected by ejector 05 + the enthalpy increase mass flow rate, that is, the main mass flow rate is equal to the mass flow rate of ejector 05, and the refrigerant liquid after injection from ejector 05 does not flash, the main suction mass flow rate of compressor 01 is equal to the gas mass flow rate absorbed by ejector 05 from the evaporator, that is, all the work done by compressor 01 is useful work.

[0101] For example, the pressure-enthalpy diagram of the enthalpy increase + injection mode Figure 7As shown, if there is no ejection mode, the suction state point of compressor 01 is point 12. At this time, it is compressed to the exhaust pressure along the isentropic line, the compression ratio is large, and compressor 01 does more work. After adding ejector 05, under the Venturi effect, the pressure after the ejection naturally rises, and the suction state point of compressor 01 rises from point 12 along the saturation line to point 1. Obviously, the pressure difference at point 1 is smaller at the condensing pressure, and compressor 01 does less work. The heating energy efficiency of the heat pump air conditioning system is higher than that of the heat pump without ejector 05. A well-designed ejector 05 can make point 1 rise as much as possible, which can further improve the energy efficiency of the heat pump air conditioning system.

[0102] The heat pump air conditioning system of the present invention also has a refrigeration function and a winter heating and defrosting function, and the cycle mode is as follows:

[0103] like Figure 1 As shown, the exhaust gas of compressor 01 enters outdoor heat exchanger 03 through four-way valve 07 and ejector 05. In this state, outdoor heat exchanger 03 changes from evaporator to condenser. Ejector 05 is in countercurrent state, Venturi effect fails, ejector 05 only acts as a communicating vessel, and the two-way valve 54 in front of ejector 05 is closed. Refrigerant gas condenses into liquid in outdoor heat exchanger 03, and enters first expansion valve 91 through second check valve and enthalpy-increasing heat exchanger 83. At this time, second expansion valve 92 and enthalpy-increasing expansion valve 82 are in closed state. Liquid refrigerant enters indoor heat exchanger 02 through liquid storage 04 after throttling and depressurization by first expansion valve 91. At this time, indoor heat exchanger 02 is converted from condenser to evaporator. Liquid refrigerant absorbs the heat of water in indoor heat exchanger 02, vaporizes and evaporates, and then returns to compressor 01 through four-way valve 07, completing the cycle.

[0104] The control device of the heat pump air conditioning system provided by the present invention is described below. The control device of the heat pump air conditioning system described below and the control method of the heat pump air conditioning system described above can be referred to each other.

[0105] like Fig. 9 As shown, a control device for a heat pump air conditioning system according to an embodiment of the third aspect of the present invention comprises:

[0106] The first acquisition module 110 is used to acquire the current working mode of the heat pump air conditioning system;

[0107] The second acquisition module 120 is used to receive a signal that the heat pump air conditioning system is in heating mode, and obtain the outdoor ambient temperature and the speed of the compressor 01;

[0108] The control module 130 is used to generate an execution logic according to the outdoor ambient temperature and the rotation speed of the compressor 01, and control the opening or closing of the two-way valve 54 according to the execution logic.

[0109] The technical effect of the control device of the heat pump air conditioning system according to the embodiment of the present invention is similar to the effect of the control method of the heat pump air conditioning system in the second embodiment of the present invention, and the present invention will not be repeated here.

[0110] Fig.10 An example of a physical structure diagram of an electronic device is shown in FIG. Fig.10 As shown, the electronic device may include: a processor 810, a communication interface 820, a memory 830 and a communication bus 840, wherein the processor 810, the communication interface 820 and the memory 830 communicate with each other through the communication bus 840. The processor 810 may call the logic instructions in the memory 830 to execute the control method of the heat pump air conditioning system described above.

[0111] In addition, the logic instructions in the above-mentioned memory 830 can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when it is sold or used as an independent product. Based on such an understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods of each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program codes.

[0112] On the other hand, the present invention also provides a computer program product, which includes a computer program. The computer program can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute the control method of the heat pump air-conditioning system described above.

[0113] On the other hand, the present invention further provides a non-transitory computer-readable storage medium having a computer program stored thereon, which is implemented when the computer program is executed by a processor to execute the control method of the heat pump air-conditioning system described above.

[0114] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative labor.

[0115] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0116] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A heat pump air conditioning system, characterized in that: include: A compressor, an indoor heat exchanger and an outdoor heat exchanger connected by a refrigerant pipeline; An ejector, the outlet of the indoor heat exchanger is respectively connected to the ejector liquid inlet of the ejector and the inlet of the outdoor heat exchanger, the outlet of the outdoor heat exchanger is connected to the ejector air suction port of the ejector, and a two-way valve is provided at the ejector liquid inlet of the ejector; A gas-liquid separator, wherein the feed port thereof is connected to the ejection liquid outlet of the ejector, and the liquid outlet of the gas-liquid separator is connected to the inlet of the outdoor heat exchanger.

2. The heat pump air conditioning system according to claim 1, characterized in that: Also includes: An enthalpy-increasing pipeline, the enthalpy-increasing pipeline is arranged between the indoor heat exchanger and the outdoor heat exchanger and is connected to the return air port of the compressor; The enthalpy-increasing pipeline is provided with an enthalpy-increasing expansion valve and an enthalpy-increasing heat exchanger, and the refrigerant pipeline between the indoor heat exchanger and the outdoor heat exchanger flows through the enthalpy-increasing heat exchanger.

3. The heat pump air conditioning system according to claim 2, characterized in that: A first expansion valve and a second expansion valve are provided between the indoor heat exchanger and the outdoor heat exchanger, the first expansion valve and the second expansion valve are respectively located upstream and downstream of the enthalpy increasing pipeline, and the first expansion valve is connected in parallel with a first check valve, and the second expansion valve is connected in parallel with a second check valve; The flow direction of the first check valve is oriented in a direction from the indoor heat exchanger to the outdoor heat exchanger, and the flow direction of the second check valve is opposite to the flow direction of the first check valve.

4. The heat pump air conditioning system according to claim 1, characterized in that: A third check valve and a capillary tube are provided between the liquid outlet of the gas-liquid separator and the inlet of the outdoor heat exchanger, and the flow direction of the third check valve is oriented along the direction from the liquid outlet of the gas-liquid separator to the inlet of the outdoor heat exchanger.

5. The heat pump air conditioning system according to any one of claims 1 to 4, characterized in that: A gas-liquid separation chamber is formed inside the gas-liquid separator; A gas-liquid inlet pipe is provided at one end of the gas-liquid separator and a liquid outlet pipe is provided at the other end. The gas-liquid inlet pipe and the liquid outlet pipe are both connected to the gas-liquid separation chamber and form a feed port and a liquid outlet, respectively. The gas-liquid inlet pipe and the liquid outlet pipe are both connected to the side wall of the gas-liquid separator and are respectively arranged along the tangent direction of the side wall of the gas-liquid separator.

6. A control method for a heat pump air conditioning system according to any one of claims 1 to 5, characterized in that: include: Obtaining the current working mode of the heat pump air conditioning system; Receiving a signal that the heat pump air conditioning system is in heating mode, obtaining the outdoor ambient temperature and the compressor speed; An execution logic is generated according to the outdoor ambient temperature and the compressor speed, and the opening or closing of the two-way valve is controlled according to the execution logic.

7. The control method of the heat pump air conditioning system according to claim 6, characterized in that: The step of generating an execution logic according to the outdoor ambient temperature and the compressor speed, and controlling the opening or closing of the two-way valve according to the execution logic specifically includes: Determining that the outdoor ambient temperature is lower than a first set temperature and the compressor speed is higher than a first set speed, controlling the two-way valve to open so that the heat pump air conditioning system enters an ejection mode; After the injection mode continues for a set time, it is determined that the outdoor ambient temperature is higher than the first set temperature and the compressor speed is lower than the second set speed, and the two-way valve is controlled to close so that the heat pump air-conditioning system exits the injection mode.

8. The control method of the heat pump air conditioning system according to claim 7, characterized in that: Also includes: It is determined that the outdoor ambient temperature is lower than a second set temperature, and the enthalpy-increasing expansion valve is controlled to open so that the heat pump air-conditioning system performs an enthalpy-increasing operation, wherein the second set temperature is greater than the first set temperature.

9. The control method of the heat pump air conditioning system according to claim 7, characterized in that: Also includes: In the ejection mode, the first expansion valve and the second expansion valve are both controlled to be closed.

10. A control device for a heat pump air conditioning system according to any one of claims 1 to 5, characterized in that: include: A first acquisition module, used to acquire the current working mode of the heat pump air-conditioning system; A second acquisition module is used to receive a signal that the heat pump air-conditioning system is in a heating mode, and acquire an outdoor ambient temperature and a compressor speed; A control module is used to generate an execution logic according to the outdoor ambient temperature and the compressor speed, and control the opening or closing of the two-way valve according to the execution logic.

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