Air conditioning system, air conditioner and control method thereof

Abstract

The application provides an air conditioning system, an air conditioner and a control method thereof. The air conditioning system comprises an air conditioning subsystem, a solar heat collection subsystem and a power generation subsystem. The power generation subsystem comprises an expander and a first working medium pump. The air conditioning subsystem comprises a compressor, an indoor heat exchanger, a first throttling device and an outdoor heat exchanger. The air conditioning system further comprises a gas-liquid separator and a first pipeline. The outlet of the expander is connected with the inlet of the gas-liquid separator. The gas outlet of the gas-liquid separator is connected with the second end of the indoor heat exchanger. The inlet of the first working medium pump is connected between the first throttling device and the first end of the indoor heat exchanger. The air conditioner comprises the air conditioning system. The control method comprises the following steps: when in a heating mode, acquiring temperature data of the outdoor heat exchanger; and if the temperature data is lower than a first preset value, controlling to enter a defrosting mode. The application couples solar energy to generate power and supply energy. The system meets the requirements of low cost, compact structure, complete functions and the like, and is suitable for household split air conditioners.

Description

Technical Field

[0001] This invention relates to the field of air conditioning technology, specifically to an air conditioning system, an air conditioner, and a control method thereof. Background Technology

[0002] Photothermal conversion involves collecting heat energy using solar collectors and using that heat energy to drive absorption chillers, adsorption chillers, and other similar systems. This method converts heat energy into cooling output.

[0003] A solar energy supply system includes a solar thermal collector subsystem, a power generation subsystem, a cooling subsystem, and a heating subsystem. The solar thermal collector subsystem is connected to the power generation subsystem via a first heat exchanger, the power generation subsystem is connected to the cooling subsystem via a second heat exchanger, and the solar thermal collector subsystem is connected to the heating subsystem via a third heat exchanger. In the solar thermal collector subsystem, the solar collector panel, collector tank, pump, first heat exchanger, and second heat exchanger are connected sequentially. High-temperature solar energy is transferred to the power generation subsystem via the first heat exchanger, while low-temperature solar energy is transferred to the heating subsystem via the third heat exchanger. The heating subsystem mainly includes a hot water tank. In the power generation system, the collected high heat is used to generate electricity through the first expander. Downstream of the first expander, there is a fourth heat exchanger for heat exchange with the system cooling water. Downstream of the fourth heat exchanger, there is the aforementioned second heat exchanger. The power generation working fluid after passing through the expander absorbs heat from the cooling water and exchanges it to the refrigeration subsystem through the second heat exchanger. The refrigeration subsystem includes a compressor, a second heat exchanger, a second expander, and a fifth heat exchanger connected in sequence. After the cold refrigerant generates electricity through the second expander, the cold energy of the low-temperature working fluid is transferred to the chilled water of the air conditioning system through the fifth heat exchanger.

[0004] The current goal is to integrate solar energy into residential air conditioning systems. While existing solar energy systems utilize solar energy for power generation, cooling, and heating, their large, complex architecture and high cost make them unsuitable for integration into large and medium-sized central air conditioning systems, rather than typical residential split-system air conditioning units. Furthermore, this system only provides sufficient cooling capacity in cooling mode; it offers no benefit in heating or defrosting modes. Therefore, the system's utilization rate of solar thermal energy is relatively low for residential air conditioning systems. Summary of the Invention

[0005] The primary objective of this invention is to provide an air conditioning system that couples solar energy to generate and supply energy, suitable for household split air conditioners.

[0006] The second objective of this invention is to provide an air conditioner that couples solar energy to generate and supply energy, suitable for household split air conditioners.

[0007] A third objective of this invention is to provide a control method for an air conditioner based on the aforementioned air conditioning system.

[0008] The air conditioning system provided by the first objective of this invention includes an air conditioning subsystem, a solar thermal collector subsystem, and a power generation system. The air conditioning subsystem includes a compressor, and the power generation system includes an expander and a first working fluid pump. The solar thermal collector subsystem exchanges heat with the power generation system through a heat exchanger, which is located between the outlet of the first working fluid pump and the inlet of the expander. The air conditioning subsystem includes, in heating mode, a compressor, an indoor heat exchanger, a first throttling device, and an outdoor heat exchanger connected sequentially. The air conditioning system also includes a gas-liquid separator and a first pipeline. The outlet of the expander is connected to the inlet of the gas-liquid separator, and the outlet of the gas-liquid separator is connected through the first pipeline between the second end of the indoor heat exchanger and the inlet of the compressor. The inlet of the first working fluid pump is connected between the first throttling device and the first end of the indoor heat exchanger.

[0009] As can be seen from the above scheme, this system is based on a household split-type air conditioner. System coupling is achieved by placing a gas-liquid separator at the intersection of the power generation cycle of the solar thermal collector subsystem and the power generation system with the heat pump cycle of the air conditioning subsystem. The working fluid, after generating electricity via the expander, enters this gas-liquid separator. First, at night or on cloudy days when solar energy flow is low, the solar thermal collector subsystem and the power generation system stop working, and excess working fluid is stored in liquid form in this container. Second, the gas-liquid separator acts as a heat storage tank. In heating mode, the working fluid separates into gaseous and liquid parts due to incomplete evaporation. The gaseous working fluid has a higher temperature and can be used to supplement indoor heating. The gaseous working fluid condenses and releases heat on the indoor side, supplementing indoor heating, while the liquid working fluid is stored in the gas-liquid separator. This liquid working fluid has a lower temperature than the indoor temperature (20°C) and cannot be used for heating, but it is still higher than the outdoor ambient temperature and can be used to heat the working fluid before the compressor inlet. Therefore, this invention is based on meeting the actual needs of a typical household split-type air conditioner, achieving power generation and multi-faceted energy supply with a simple system architecture.

[0010] A further proposed solution is that the pipeline between the compressor and the first end of the outdoor heat exchanger passes through the gas-liquid separator, and the working fluid in the pipeline between the compressor and the first end of the outdoor heat exchanger does not mix with the working fluid in the gas-liquid separator.

[0011] As can be seen above, in heating mode, when the outdoor temperature is below -15℃, the working fluid temperature and pressure at the compressor inlet decrease, resulting in a reduced working fluid flow and causing problems such as low heating capacity and poor circulation performance. In this system, the compressor inlet pipeline passes through a gas-liquid separator, heating the working fluid before it enters the compressor. This effectively alleviates the aforementioned heating capacity reduction problem. With this simple improvement, a multi-faceted energy supply effect is achieved, further enhancing energy efficiency.

[0012] A further embodiment includes an air conditioning subsystem comprising a four-way valve, a second throttling device, a first valve, a second valve, and a second pipeline. The four-way valve is used to switch the air conditioning system between cooling and heating modes. The second end of the outdoor heat exchanger, the first throttling device, and the second throttling device are sequentially connected to the first end of the indoor heat exchanger. The inlet of the first working fluid pump is connected between the first and second throttling devices. The first valve is located in the first pipeline. The second pipeline is located between the outlet of the gas-liquid separator and the inlet of the outdoor heat exchanger, and the second valve is located in the second pipeline. The air conditioning system can enter a power generation and cooling mode. When the air conditioning system is in power generation and cooling mode, the compressor, the first working fluid pump, and the expander all operate. The first throttling device is at its maximum opening, the second throttling device is in a throttling state, the first valve is closed, and the second valve is open.

[0013] As can be seen from the above, this setting further improves the functionality of the air conditioning system, enabling it to operate in either power generation / cooling mode or general cooling mode.

[0014] A further proposed solution is that the air conditioning subsystem also includes a third valve and a fourth valve; the third valve is located between the first end of the outdoor heat exchanger and the four-way valve, and the fourth valve is located between the second end of the indoor heat exchanger and the four-way valve; the air conditioning system can enter a power generation mode; when the air conditioning system is in power generation mode, the compressor stops, the first working fluid pump and the expander both work, the first throttling device is at its maximum opening, the second throttling device is closed, the first valve, the third valve and the fourth valve are all closed, and the second valve is open.

[0015] As can be seen from the above, this setting further improves the functionality of the air conditioning system. The air conditioning system can operate in power generation mode. When the user has no need for cooling or heating, the power generation mode can be activated and used only for outputting electricity.

[0016] A further proposed solution is to include two heating modes: a power generation heating mode and a general heating mode. When the air conditioning system is in power generation heating mode, the compressor, the first working fluid pump, and the expander are all operating, the second throttling device is at its maximum opening, the first throttling device is in a throttling state, the first valve is open, and the second valve is closed. When the air conditioning system is in general heating mode, the compressor is operating, the first working fluid pump and the expander are both off, the second throttling device is at its maximum opening, the first throttling device is in a throttling state, the first valve is open, and the second valve is closed.

[0017] As can be seen from the above, in the power generation and heating mode, after power generation is completed, the working fluid undergoes gas-liquid separation in the gas-liquid separator. The gaseous portion of the working fluid enters the indoor heat exchanger through the first pipeline to supplement indoor heating, while the liquid portion remains in the separator. Furthermore, in extremely cold weather, the expander can operate under no-load conditions. In this state, the system has no electrical output, and solar heat is entirely supplied to the indoor environment, increasing the system's low-temperature heating capacity. Additionally, in extremely cold weather, the heating capacity of the air source heat pump system decreases, and the acquired solar heat also decreases further. At this time, based on the heating mode, the working fluid pump and expander stop working. The working fluid flowing through the power generation circuit absorbs heat in the heat exchanger and then directly enters the indoor heat exchanger through the first pipeline. In this operating state, the acquired solar heat is entirely used for heating, with no electrical output. This setup further achieves the effect of multi-faceted energy supply and further improves energy utilization efficiency.

[0018] A further solution is to allow the air conditioning system to enter defrost mode; when the air conditioning system is in defrost mode, the compressor, the first working fluid pump and the expander are all working, the second throttling device is at its maximum opening, the first throttling device is in a throttling state, and both the first valve and the second valve are open.

[0019] As can be seen above, when the outdoor unit of the air conditioner is severely frosted, opening the second valve allows the liquid working fluid stored in the gas-liquid separator to be released into the outdoor heat exchanger through the second pipeline for defrosting. Compared to the traditional reversing defrosting method, this method effectively solves the problem of no heating output indoors during defrosting time by eliminating the compressor shutdown and four-way valve reversal process.

[0020] A further proposed solution is that the solar thermal collector subsystem includes a second working fluid pump, a solar collector, a heat exchanger, and a liquid storage tank connected in sequence.

[0021] The second objective of this invention is to provide an air conditioner that includes the aforementioned air conditioning system.

[0022] The third objective of this invention is to provide a control method for an air conditioner, wherein the air conditioner includes an air conditioning system, the air conditioning system adopts the aforementioned air conditioning system; the control method includes: when in heating mode, acquiring temperature data about the outdoor heat exchanger; if the temperature data is lower than a first preset value, controlling the system to enter defrost mode, and controlling the second valve to open.

[0023] As can be seen from the above scheme, when the outdoor heat exchanger pipe temperature is detected to be below a certain value in heating mode, it will be determined to be in a frosting state, and the system will enter defrosting mode. In defrosting mode, based on the heating mode control logic, the second valve changes from closed to open. In this defrosting mode, the gas-liquid separator releases the stored liquid working fluid into the outdoor heat exchanger, mixes with the working fluid therein, and raises the temperature of the outdoor heat exchanger pipe, achieving a defrosting effect; until the pipe temperature is higher than the set temperature, the second valve closes again, exiting defrosting mode. During this process, the compressor runs continuously, and the system can ensure a stable output of heating capacity to users.

[0024] A further option is that the control method also includes acquiring heating data of the solar collector subsystem when in power generation and heating mode; if the heating data is lower than a second preset value, controlling the system to enter normal heating mode and controlling the first working fluid pump and expander to shut down.

[0025] As can be seen from the above, in extremely cold weather, the heating capacity of the air source heat pump system decreases, and the solar heat obtained is further reduced. At this time, in heating mode, the working fluid pump and expander stop working. The working fluid flowing through the power generation circuit absorbs heat in the heat exchanger and then directly enters the indoor side through the first pipe. In this operating state, the obtained solar heat is entirely used for heating, and there is no electricity output. Attached Figure Description

[0026] Figure 1 This is a system schematic diagram of an embodiment of the air conditioning system of the present invention.

[0027] Figure 2 This is a system schematic diagram of the air conditioning system embodiment of the present invention in the mode of generating electricity and heating.

[0028] Figure 3 This is a system schematic diagram of the air conditioning system embodiment of the present invention in the power generation and cooling mode.

[0029] Figure 4 This is a system schematic diagram of the defrosting mode in an embodiment of the air conditioning system of the present invention.

[0030] Figure 5 This is a system schematic diagram of the power generation mode in an embodiment of the air conditioning system of the present invention. Detailed Implementation

[0031] Air conditioning system example See Figure 1 The air conditioning system in this embodiment includes an air conditioning subsystem, a solar thermal collector subsystem, and a power generation system.

[0032] The air conditioning subsystem includes compressor 1, four-way valve 2, indoor heat exchanger 3, outdoor heat exchanger 4, first throttling device 10, second throttling device 11, first valve 8, first pipeline 81, second valve 9, second pipeline 91, third valve 6 and fourth valve 7, wherein the first throttling device 10 and the second throttling device 11 are both throttling valves.

[0033] The four-way valve 2 is located between the compressor 1 and the second end 32 of the indoor heat exchanger 3 and the first end 41 of the outdoor heat exchanger 4. The inlet and outlet of the compressor 1 are both connected to the four-way valve 2. The second end 42 of the outdoor heat exchanger 4, the first throttling device 10, the second throttling device 11 are sequentially connected to the first end 31 of the indoor heat exchanger 3.

[0034] The four-way valve 2 is used to switch the air conditioning system between cooling and heating modes. See also Figure 2 In cooling mode, compressor 1, outdoor heat exchanger 4, first throttling device 10, second throttling device 11, and indoor heat exchanger 3 are connected sequentially from end to end. (See also...) Figure 3 In heating mode, compressor 1, indoor heat exchanger 3, second throttling device 11, first throttling device 10, and outdoor heat exchanger 4 are connected end to end in sequence.

[0035] See Figure 1 The solar thermal collector subsystem includes a second working fluid pump 16, a solar collector 14, a heat exchanger 17, and a liquid storage tank 15, connected sequentially from end to end. The power generation system includes an expander 13 and a first working fluid pump 12.

[0036] See Figure 1 The air conditioning system also includes a gas-liquid separator 5 located at the intersection of the air conditioning subsystem and the power generation system circuit. In the power generation system, a heat exchanger 17 is located between the outlet of the first working fluid pump 12 and the inlet of the expander 13. The outlet of the expander 13 is connected to the inlet 51 of the gas-liquid separator 5. The gas outlet 52 of the gas-liquid separator 5 is connected through a first pipe 81 between the second end 32 of the indoor heat exchanger 3 and the inlet of the compressor 1. The liquid outlet 53 of the gas-liquid separator 5 is connected through a second pipe 91 to the inlet of the outdoor heat exchanger 4. The inlet of the first working fluid pump 12 is connected between the first throttling device 10 and the second throttling device 11. Of course, the inlet of the first working fluid pump 12 is connected to the pipe between the first throttling device 10 and the first end of the indoor heat exchanger 3.

[0037] In addition, the first valve 8 is installed on the first pipe 81, and the second valve 9 is installed on the second pipe 91. The third valve 6 is installed on the pipe between the first end 41 of the outdoor heat exchanger 4 and the four-way valve 2, and the fourth valve 7 is installed on the pipe between the second end 32 of the indoor heat exchanger 3 and the four-way valve 2. Specifically, the first pipe 81 is connected to the pipe between the second end 32 of the indoor heat exchanger 3 and the fourth valve 7.

[0038] Additionally, the pipe between compressor 1 and the first end 41 of outdoor heat exchanger 4 passes through gas-liquid separator 5. In this embodiment, specifically, the pipe between third valve 6 and the first end 41 of outdoor heat exchanger 4 passes through the working fluid chamber of gas-liquid separator 5. Thus, the pipe between third valve 6 and the first end 41 of outdoor heat exchanger 4 can absorb heat from the working fluid in gas-liquid separator 5, but the working fluid in the pipe between third valve 6 and the first end 41 of outdoor heat exchanger 4 does not mix with the working fluid in gas-liquid separator 5.

[0039] The air conditioning system of the present invention can enter multiple modes such as cooling mode, heating mode, defrosting mode and power generation mode. The cooling mode includes power generation cooling mode and general cooling mode, and the heating mode includes power generation heating mode and general heating mode.

[0040] See Figure 2 When the air conditioning system is in the power generation and cooling mode, the four-way valve 2 is adjusted to the first state as shown in Figure 2. The compressor 1, the first working fluid pump 12 and the expander 13 are all working. The first throttling device 10 is at its maximum opening and does not produce a throttling effect. The second throttling device 11 is in a throttling state and produces a throttling effect. The first valve 8 is closed, and the second valve 9, the third valve 6 and the fourth valve 7 are all open.

[0041] In this operating state, the working fluid in the indoor heat exchanger 3 is at the first pressure, the working fluid in the outdoor heat exchanger 4 is at the second pressure, and the working fluid in the heat exchanger 17 is at the third pressure. The third pressure is greater than the second pressure, and the second pressure is greater than the first pressure.

[0042] The working fluid, pressurized to the second pressure by compressor 1, first enters the outdoor heat exchanger 4 for condensation and heat release. Then, the working fluid is divided into two streams: One working fluid is throttled and depressurized to the first pressure by the second throttling device 11, then enters the indoor heat exchanger 3 to evaporate and absorb heat, and finally returns to the compressor 1.

[0043] Another working fluid is pressurized to the third pressure by the first working fluid pump 12 and then enters the heat exchanger 17 to evaporate and absorb heat. Subsequently, it expands and does work, driving the expander 13 to rotate and generate electricity. During the expansion and work process, the working fluid pressure drops to the second pressure. Then, the working fluid enters the gas-liquid separator 5 from the inlet 51 and then enters the outdoor heat exchanger 4 through the second pipeline 91, where it mixes with the working fluid sent out from the outlet of the compressor 1 in the outdoor heat exchanger 4.

[0044] See also Figure 2 However, if there is insufficient solar heat but an increased demand for cooling, the first working fluid pump 12 and the expander 13 can be stopped to stop power generation and operate in normal cooling mode.

[0045] See Figure 3 When the air conditioning system is in power generation and heating mode, the four-way valve 2 is adjusted to the second state as shown in Figure 3. The compressor 1, the first working fluid pump 12 and the expander 13 are all working. The second throttling device 11 is at its maximum opening and does not produce a throttling effect. The first throttling device 10 is in a throttling state and produces a throttling effect. The first valve 8, the third valve 6 and the fourth valve 7 are all open, and the second valve 9 is closed.

[0046] At this time, the indoor heat exchanger 3 acts as a condenser, and the outdoor evaporator 4 acts as an evaporator. The working fluid in the indoor heat exchanger 3 is at the second pressure, the working fluid in the outdoor heat exchanger 4 is at the first pressure, and the working fluid in the heat exchanger 17 is at the third pressure. The working fluid at the second pressure at the compressor 1 outlet passes through the indoor heat exchanger 3 and the second throttling device 11 after being switched by the four-way valve 2. Then, one of the working fluids is throttled and depressurized to the first pressure by the throttling valve 10, and then condenses and releases heat in the outdoor evaporator 4, before finally returning to the compressor 1.

[0047] The working fluid following the second throttling device 11 is pressurized to a third pressure by the first working fluid pump 12, then enters the heat exchanger 17 for evaporation and heat absorption. Subsequently, it expands, driving the expander 13 to rotate and generate electricity, before decreasing to a second pressure. Due to limited solar energy harvesting in winter, incomplete evaporation may occur during the heat absorption process in the heat exchanger 17, resulting in a two-phase flow of gas and liquid in the working fluid flowing through the vapor-liquid separator 5. The gaseous portion of the working fluid is sent through the first pipeline 81 to the second end 32 of the indoor heat exchanger 3, where it mixes with the working fluid from the compressor 1 outlet and enters the indoor heat exchanger 3 together, supplementing its heating capacity. The liquid portion is stored in the vapor-liquid separator 5.

[0048] In extremely cold weather, the heating capacity of the air source heat pump system decreases, and the amount of solar heat obtained also decreases further. At this time, it can operate in normal heating mode. When the air conditioning system is in normal heating mode, compressor 1 is working, the first working fluid pump 12 and expander 13 are both off, the second throttling device 11 is at its maximum opening, the first throttling device 10 is in a throttling state, the first valve 8 is open, and the second valve 9 is closed. The working fluid flowing through the heat exchanger system absorbs heat in the heat exchanger 17 and then directly enters the indoor heat exchanger 3 through the first pipe 81. In this operating state, the obtained solar heat is entirely used for heating, and there is no electricity output.

[0049] See Figure 4 In heating mode, when the outdoor heat exchanger pipe temperature is detected to be below a certain value, it will be determined to be in a frosting state, and the system will enter defrosting mode. In defrosting mode, based on the heating mode control logic, the second valve 9 will be changed from closed to open. That is, when the air conditioning system is in defrosting mode, the compressor 1, the first working fluid pump 12, and the expander 13 are all working, the second throttling device 11 is at its maximum opening, the first throttling device 10 is in a throttling state, and the first valve 8, the second valve 9, the third valve 6, and the fourth valve 7 are all open.

[0050] In this operating state, the gas-liquid separator 5 releases the stored liquid working fluid through the outlet 53 and the second pipeline 91 into the outdoor heat exchanger 4, where it mixes with the working fluid and raises the pipe temperature of the outdoor heat exchanger 4, achieving a defrosting effect. Once the pipe temperature of the outdoor heat exchanger 4 exceeds the set temperature, the second valve 9 closes again, exiting the defrosting mode. During this process, the compressor 1 runs continuously, ensuring a stable output of heating capacity to the user.

[0051] See Figure 5 When the user does not require air conditioning, the power generation mode can be activated, which is used only for power output. When the air conditioning system is in power generation mode, compressor 1 stops, the first working fluid pump 12 and expander 13 both operate, the first throttling device 10 is at its maximum opening, the second throttling device 11 is closed, the first valve 8, the third valve 6, and the fourth valve 7 are all closed, and the second valve 9 is open. In this mode, compressor 1 stops working, and only the first working fluid pump 12 is used as the power source. In this operating state, the working fluid in the system is pressurized by the first working fluid pump 12, enters the heat exchanger 17 for evaporation and heat absorption, and drives the expander 13 to rotate to generate electricity. It then enters the heat exchanger 4 for condensation and heat release, and finally returns to the first working fluid pump 12.

[0052] It should be noted that in this embodiment, the pipeline between the third valve 6 and the first end 41 of the outdoor heat exchanger 4 passes through the working fluid chamber of the gas-liquid separator 5. In heating mode, when the temperature of the outdoor heat exchanger 4 is below -15℃, the refrigerant flow rate decreases due to the reduced temperature and pressure of the refrigerant at the compressor 1 inlet, resulting in low heating capacity and poor circulation performance. This system is designed so that the pipeline at the compressor 1 inlet, i.e., the pipeline between the third valve 6 and the first end 41 of the outdoor heat exchanger 4, exchanges heat through the gas-liquid separator 5. The gas-liquid separator 5 heats the working fluid before it enters the compressor 1, effectively alleviating the aforementioned heating capacity reduction problem and further improving energy efficiency.

[0053] Example of an air conditioner control method The air conditioner includes the air conditioning system of the above embodiment, and the control method of the air conditioner includes: When in heating mode, the system acquires temperature data of the detection pipe temperature of the outdoor heat exchanger 4. If the temperature data is lower than the first preset value, the system controls the entry into defrosting mode and controls the opening of the second valve 9. If the temperature data is higher than the first preset value, the system controls the exit from defrosting mode and controls the closing of the second valve 9.

[0054] When in power generation and heating mode, acquire heating data of the solar collector subsystem. If the heating data is lower than the second preset value, control to enter normal heating mode and control the first working fluid pump 12 and expander 13 to stop.

[0055] As can be seen, compared with the large, complex and costly solar power systems in the background technology, the air conditioning system of the present invention, which combines a heat pump circuit and a solar power generation circuit based on a gas-liquid separator, not only realizes power generation and multi-faceted energy supply, but also meets the requirements of low cost, compact structure and full functionality. It achieves more beneficial effects with the simplest possible system and structure, and meets the actual needs of general household split air conditioners.

[0056] Finally, it should be emphasized that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An air conditioning system, comprising an air conditioning subsystem, a solar thermal collector subsystem, and a power generation system, wherein the air conditioning subsystem includes a compressor, the power generation system includes an expander and a first working fluid pump, and the solar thermal collector subsystem exchanges heat with the power generation system through a heat exchanger, wherein the heat exchanger is disposed between the outlet of the first working fluid pump and the inlet of the expander; Its features are: The air conditioning subsystem includes, in heating mode, the compressor, the indoor heat exchanger, the first throttling device, and the outdoor heat exchanger, which are connected in sequence from end to end. The air conditioning system also includes a gas-liquid separator and a first pipeline; The outlet of the expander is connected to the inlet of the gas-liquid separator, and the outlet of the gas-liquid separator is connected through the first pipeline between the second end of the indoor heat exchanger and the inlet of the compressor. The inlet of the first working fluid pump is connected between the first throttling device and the first end of the indoor heat exchanger; The air conditioning subsystem also includes a four-way valve, a second throttling device, a first valve, a second valve, and a second pipeline; The four-way valve is used to switch the air conditioning system between cooling mode and heating mode; The second end of the outdoor heat exchanger, the first throttling device, the second throttling device and the first end of the indoor heat exchanger are connected in sequence, and the inlet of the first working fluid pump is connected between the first throttling device and the second throttling device; The first valve is installed in the first pipeline; The second pipeline is located between the liquid outlet of the gas-liquid separator and the inlet of the outdoor heat exchanger, and the second valve is located in the second pipeline; When the air conditioning system is in power generation and cooling mode, the compressor, the first working fluid pump, and the expander are all working. The first throttling device is at its maximum opening, the second throttling device is in a throttling state, the first valve is closed, and the second valve is open.

2. The air conditioning system according to claim 1, characterized in that: The solar thermal collector subsystem includes a second working fluid pump, a solar collector, a heat exchanger, and a liquid storage tank connected in sequence.

3. The air conditioning system according to claim 1, characterized in that: The pipeline between the compressor and the first end of the outdoor heat exchanger passes through the gas-liquid separator, and the working fluid in the pipeline between the compressor and the first end of the outdoor heat exchanger does not mix with the working fluid in the gas-liquid separator.

4. The air conditioning system according to any one of claims 1 to 3, characterized in that: The air conditioning subsystem also includes a third valve and a fourth valve; The third valve is located between the first end of the outdoor heat exchanger and the four-way valve, and the fourth valve is located between the second end of the indoor heat exchanger and the four-way valve. When the air conditioning system is in power generation mode, the compressor stops, the first working fluid pump and the expander both work, the first throttling device is at its maximum opening, the second throttling device is closed, the first valve, the third valve and the fourth valve are all closed, and the second valve is open.

5. The air conditioning system according to claim 4, characterized in that: The heating modes include power generation heating mode and general heating mode; When the air conditioning system is in the power generation and heating mode, the compressor, the first working fluid pump, and the expander are all working, the second throttling device is at its maximum opening, the first throttling device is in a throttling state, the first valve is open, and the second valve is closed; When the air conditioning system is in the general heating mode, the compressor is working, the first working fluid pump and the expander are both stopped, the second throttling device is at its maximum opening, the first throttling device is in a throttling state, the first valve is open, and the second valve is closed.

6. The air conditioning system according to claim 5, characterized in that: The air conditioning system can enter defrost mode; When the air conditioning system is in defrosting mode, the compressor, the first working fluid pump, and the expander are all working, the second throttling device is at its maximum opening, the first throttling device is in a throttling state, and both the first valve and the second valve are open.

7. An air conditioner, characterized in that, The air conditioning system includes any one of claims 1 to 6.

8. A control method for an air conditioner, characterized in that: The air conditioner includes an air conditioning system, and the air conditioning system adopts the air conditioning system described in claim 6 above; The control method includes: When the air conditioning system is in the heating mode, it acquires the temperature data of the outdoor heat exchanger. If the temperature data is lower than a first preset value, it controls the system to enter the defrosting mode and controls the opening of the second valve.

9. The control method for an air conditioner according to claim 8, characterized in that: The control method further includes: When in the power generation and heating mode, acquire the heating data of the solar collector subsystem. If the heating data is lower than the second preset value, control the system to enter the general heating mode and control the first working fluid pump and the expander to stop.

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