Air conditioning system and control method thereof

Abstract

The invention relates to the technical field of air conditioners, particularly provides an air conditioning system and a control method thereof, and aims to solve the problems that condensation is easily generated and the temperature is too high to facilitate heat dissipation in an existing refrigerant heat dissipation mode. In order to achieve the purpose, the air conditioning system comprises an outdoor heat exchanger, a first control valve, a refrigerant radiator, a third control valve and an indoor heat exchanger which are connected in sequence; the refrigerant radiator is used for radiating a driving module of the air conditioning system; the third control valve only allows the refrigerant to flow from the refrigerant radiator to the indoor heat exchanger; the air conditioning system further comprises a second control valve which bypasses the refrigerant radiator and the first control valve, and the second control valve is configured to only allow the refrigerant to flow to the outdoor heat exchanger from the side away from the outdoor heat exchanger. By adjusting the opening degree of the first control valve and / or the fourth control valve, it can be guaranteed that the temperature of the refrigerant radiator is controlled within a proper range in all the modes, cooling and heat dissipation of the driving module are guaranteed, and it is also guaranteed that condensation cannot be generated.

Description

Technical Field

[0001] The present invention relates to the technical field of air conditioners, and particularly provides an air conditioning system and a control method thereof. Background Art

[0002] In existing air conditioning systems that use refrigerant to dissipate heat from the driving module of a compressor, they cannot fully accommodate all operating conditions of refrigeration and heating, and there are the following problems: First, in high-temperature operating conditions, the heat dissipation effect of the refrigerant is poor, resulting in high temperatures of electrical components, insufficient compressor frequency, and poor performance in high-temperature operating conditions. It is necessary to improve by increasing the refrigerant radiator, resulting in a large size of the refrigerant radiator, large space occupation, and high cost; Second, the temperature of the refrigerant used to cool the driving module is too low, resulting in condensation on the driving module, and even the risk of short-circuit damage to electrical components. In summary, the existing control methods for refrigerant radiators cannot ensure that condensation is prevented on the driving module in both refrigeration and heating modes. Either the refrigerant temperature is too high, resulting in poor heat dissipation of the driving module; or the refrigerant temperature is too low, resulting in condensation on the driving module.

[0003] To solve the above problems, the existing variable-frequency air conditioner power module refrigerant heat dissipation throttling system includes: a compressor, a reversing valve, an outdoor heat exchanger, a refrigerant heat dissipation pipe, and an indoor heat exchanger connected in sequence. It also includes a driving module, and the driving module is coupled for heat exchange with the refrigerant heat dissipation pipe. An electronic expansion valve is provided between the outdoor heat exchanger and the refrigerant heat dissipation pipe, and a one-way throttle valve is provided between the refrigerant heat dissipation pipe and the indoor heat exchanger. In the flow direction from the refrigerant heat dissipation pipe to the indoor heat exchanger, the one-way throttle valve throttles the refrigerant. In the flow direction from the indoor heat exchanger to the refrigerant heat dissipation pipe, the one-way throttle valve is fully open. In the refrigeration mode of this technical solution, first, it is assisted by the electronic expansion valve for throttling within 20%; after passing through the refrigerant radiator, it is then throttled by the one-way throttle valve. Since the temperature and humidity change with the weather during the use of the air conditioner, the outdoor temperature operating conditions change greatly, and in some cases, the piping changes during installation, and the refrigerant needs to be increased or decreased. Throttling within 20% may also cause the temperature of the refrigerant entering the refrigerant radiator to be too low, resulting in the risk of condensation on the driving module coupled to the refrigerant radiator; in the heating mode, the refrigerant first flows reversely through the one-way throttle valve. During this process, the relatively high refrigerant temperature is not conducive to heat dissipation of the driving module.

[0004] Therefore, there is an urgent need for an air conditioning system and a control method thereof to solve the above technical problems. Summary of the Invention

[0005] The present invention aims to solve the above technical problems, that is, to solve the problems that the existing refrigerant heat dissipation methods are prone to condensation and too high temperature is not conducive to heat dissipation.

[0006] In a first aspect, the present invention provides an air conditioning system, which includes an outdoor heat exchanger, a first control valve, a refrigerant radiator, a third control valve, and an indoor heat exchanger connected in sequence; the refrigerant radiator is used to dissipate heat from the driving module of the air conditioning system; the third control valve only allows the refrigerant to flow from the refrigerant radiator to the indoor heat exchanger; the air conditioning system further includes:

[0007] A second control valve, which is bypassed between the refrigerant radiator and the first control valve, and the second control valve is configured to only allow the refrigerant to flow from the side away from the outdoor heat exchanger to the outdoor heat exchanger.

[0008] In a specific embodiment of the above air conditioning system, the air conditioning system further includes a fourth control valve, which is bypassed between the refrigerant radiator and the third control valve.

[0009] In a specific embodiment of the above air conditioning system, the air conditioning system further includes a first temperature detection component, which is arranged on the side of the refrigerant radiator close to the first control valve and is used to detect the temperature of the refrigerant flowing into or out of the refrigerant radiator; and / or

[0010] The air conditioning system further includes a second temperature detection component, which is arranged at the driving module and is used to detect the temperature of the driving module.

[0011] In a second aspect, the present invention provides a control method for the above-mentioned air conditioning system, characterized in that the control method includes:

[0012] According to the working mode of the air conditioning system and the dew point temperature of the ambient air, control the opening degrees of the first control valve and / or the fourth control valve to control the temperature of the refrigerant at the inlet of the refrigerant radiator.

[0013] In a specific embodiment of the control method of the above air conditioning system, "According to the working mode of the air conditioning system and the dew point temperature of the ambient air, control the opening degrees of the first control valve and / or the fourth control valve to control the temperature of the refrigerant at the inlet of the refrigerant radiator" includes:

[0014] In the cooling mode, adjust the opening degrees of the first control valve and / or the fourth control valve so that the temperature of the refrigerant at the inlet of the refrigerant radiator is between the ambient temperature and the dew point temperature, where the ambient temperature is higher than the dew point temperature;

[0015] Preferably, in the cooling mode, when the load of the air conditioning system is greater than a preset load, control the fourth control valve to close, and adjust the opening degree of the first control valve so that the temperature of the refrigerant at the inlet of the refrigerant radiator is between the ambient temperature and the dew point temperature;

[0016] In the refrigeration mode, when the load of the air conditioning system is not greater than the preset load, adjust the opening degrees of the first control valve and the fourth control valve so that the refrigerant temperature at the inlet of the refrigerant radiator is between the ambient temperature and the dew point temperature.

[0017] In a specific embodiment of the control method of the above air conditioning system, "controlling the opening degrees of the first control valve and / or the third control valve according to the working mode of the air conditioning system and the dew point temperature of the ambient air to control the refrigerant temperature at the inlet of the refrigerant radiator" includes:

[0018] In the refrigeration mode, adjust the opening degrees of the first control valve and / or the fourth control valve so that the refrigerant temperature at the inlet of the refrigerant radiator is between the first preset dew point temperature and the temperature of the drive module, where the first preset dew point temperature is lower than the temperature of the drive module.

[0019] Preferably, in the refrigeration mode, when the load of the air conditioning system is greater than the preset load, control the fourth control valve to close, and adjust the opening degree of the first control valve so that the refrigerant temperature at the inlet of the refrigerant radiator is between the first preset dew point temperature and the temperature of the drive module;

[0020] In the refrigeration mode, when the load of the air conditioning system is not greater than the preset load, adjust the opening degrees of the first control valve and the fourth control valve so that the refrigerant temperature at the inlet of the refrigerant radiator is between the first preset dew point temperature and the temperature of the drive module.

[0021] In a specific embodiment of the control method of the above air conditioning system, "controlling the opening degrees of the first control valve and / or the third control valve according to the working mode of the air conditioning system and the dew point temperature of the ambient air to control the refrigerant temperature at the inlet of the refrigerant radiator" includes:

[0022] In the heating mode, close the first control valve, and adjust the opening degree of the fourth control valve so that the refrigerant temperature at the inlet of the refrigerant radiator is greater than the second preset dew point temperature;

[0023] Preferably, the refrigerant temperature at the inlet of the refrigerant radiator is between the second preset dew point temperature and the temperature of the drive module, where the second preset dew point temperature is lower than the temperature of the drive module.

[0024] In a specific embodiment of the control method of the above air conditioning system, "controlling the opening degrees of the first control valve and / or the third control valve according to the working mode of the air conditioning system and the dew point temperature of the ambient air to control the refrigerant temperature at the inlet of the refrigerant radiator" includes:

[0025] Before the defrosting mode is switched, in the heating mode, the first control valve is closed, and the opening degree of the fourth control valve is adjusted so that the refrigerant temperature at the inlet of the refrigerant radiator is greater than the third preset dew point temperature; then it is switched to the cooling mode for defrosting.

[0026] Preferably, the refrigerant temperature at the inlet of the refrigerant radiator is between the third preset dew point temperature and the temperature of the driving module, where the third preset dew point temperature is lower than the temperature of the driving module.

[0027] In the specific implementation of the control method of the above air-conditioning system, when the air-conditioning system is switched to the cooling mode for defrosting, at the initial stage of defrosting, the fourth control valve is closed, and the opening degree of the first control valve is adjusted so that the refrigerant temperature at the inlet of the refrigerant radiator is greater than the fourth preset dew point temperature; where the fourth preset dew point temperature is lower than the temperature of the driving module;

[0028] Preferably, the opening degree of the first control valve is adjusted so that the refrigerant temperature at the inlet of the refrigerant radiator is greater than the fourth preset dew point temperature and less than the fourth preset dew point temperature + preset temperature difference;

[0029] In the later stage of defrosting, the opening degrees of the first control valve and the fourth control valve are adjusted so that the refrigerant temperature at the inlet of the refrigerant radiator is greater than the fourth preset dew point temperature;

[0030] Preferably, the opening degrees of the first control valve and the fourth control valve are adjusted so that the refrigerant temperature at the inlet of the refrigerant radiator is greater than the fourth preset dew point temperature and less than the fourth preset dew point temperature + preset temperature difference;

[0031] In the specific implementation of the control method of the above air-conditioning system, in the maximum load state of the air-conditioning system, the maximum temperature difference between the inlet and outlet of the refrigerant radiator is δT;

[0032] The first preset dew point temperature, the second preset dew point temperature, the third preset dew point temperature, and the fourth preset dew point temperature are all determined according to δT and the dew point temperature.

[0033] In the case of adopting the above technical solution, the air-conditioning system of the present invention includes an outdoor heat exchanger, a first control valve, a refrigerant radiator, a third control valve, and an indoor heat exchanger connected in sequence; the refrigerant radiator is used to dissipate heat from the driving module of the air-conditioning system; the third control valve only allows the refrigerant to flow from the refrigerant radiator to the indoor heat exchanger; the air-conditioning system further includes: a second control valve, which is bypassed between the refrigerant radiator and the first control valve, and the second control valve is configured to only allow the refrigerant to flow from the side far from the outdoor heat exchanger to the outdoor heat exchanger.

[0034] In the refrigeration mode, adjust the opening degrees of the first control valve and / or the fourth control valve so that the refrigerant temperature at the inlet of the refrigerant radiator is between the ambient temperature and the dew point temperature; this can not only cool and dissipate heat from the drive module, but also ensure that condensation does not occur.

[0035] In the heating mode, close the first control valve and adjust the opening degree of the fourth control valve so that the refrigerant temperature at the inlet of the refrigerant radiator is greater than the second preset dew point temperature; this can not only cool and dissipate heat from the drive module, but also ensure that condensation does not occur.

[0036] Before the defrost mode is switched, in the heating mode, close the first control valve and adjust the opening degree of the fourth control valve so that the refrigerant temperature at the inlet of the refrigerant radiator is greater than the third preset dew point temperature; then switch to the refrigeration mode for defrosting. At the initial stage of defrosting, close the fourth control valve and adjust the opening degree of the first control valve so that the refrigerant temperature at the inlet of the refrigerant radiator is greater than the fourth preset dew point temperature; in the later stage of defrosting, adjust the opening degrees of the first control valve and the fourth control valve so that the refrigerant temperature at the inlet of the refrigerant radiator is greater than the fourth preset dew point temperature; this can not only cool and dissipate heat from the drive module, but also ensure that condensation does not occur.

[0037] In summary, by adjusting the opening degrees of the first control valve and / or the fourth control valve, it can be ensured that in each mode of the air conditioning system, the temperature of the refrigerant radiator can be controlled within a suitable range, which can not only effectively cool and dissipate heat from the drive module, but also ensure that condensation does not occur. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The following describes the preferred embodiments of the present invention with reference to the accompanying drawings, in which:

[0039] Figure 1 is a schematic structural diagram of the air conditioning system provided in Embodiment 1 of the present invention;

[0040] Figure 2 is a main step flow chart of the control method of the air conditioning system provided in Embodiment 1 of the present invention;

[0041] Figure 3 is a detailed step flow chart of the control method of the air conditioning system provided in Embodiment 1 of the present invention;

[0042] Figure 4 is a schematic structural diagram of the air conditioning system provided in Embodiment 3 of the present invention;

[0043] Figure 5 is a schematic structural diagram of the air conditioning system provided in Embodiment 4 of the present invention;

[0044] Figure 6 is a schematic structural diagram of the air conditioning system provided in Embodiment 5 of the present invention;

[0045] Figure 7 It is a schematic structural diagram of the air-conditioning system provided by Embodiment 6 of the present invention.

[0046] List of reference numerals: 1, outdoor heat exchanger; 2, first control valve; 3, refrigerant radiator; 4, third control valve; 5, indoor heat exchanger; 6, compressor; 7, gas-liquid separator; 8, four-way valve; 9, gas-side stop valve; 10, liquid-side stop valve; 11, first temperature detector; 12, fourth control valve; 13, second control valve. Detailed implementation manners

[0047] The preferred implementation manners of the present invention will be described below with reference to the accompanying drawings. Those skilled in the art should understand that these implementation manners are only used to explain the technical principle of the present invention and are not intended to limit the protection scope of the present invention.

[0048] It should be noted that in the description of the present invention, the terms indicating directions or positional relationships such as "upper", "lower", "left", "right", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings. This is only for convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0049] In addition, it should also be noted that in the description of the present invention, unless otherwise clearly specified and defined, the terms "installation", "setting", "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, and can also be the communication inside two elements. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0050] In order to solve the problems that the existing refrigerant heat dissipation methods are prone to condensation and the temperature is too high, which is not conducive to heat dissipation.

[0051] As Figure 1 shown, this embodiment discloses an air-conditioning system, which includes an outdoor heat exchanger 1, a first control valve 2, a refrigerant radiator 3, a third control valve 4, and an indoor heat exchanger 5 connected in sequence.

[0052] The third control valve 4 is specifically a throttle check valve, that is, a throttle non-return valve. The third control valve 4 only allows the refrigerant to flow from the refrigerant radiator 3 to the indoor heat exchanger 5.

[0053] In this embodiment, the first control valve 2 is specifically an electric ball valve, and the flow rate of the electric ball valve can be controlled by adjusting the opening degree of the electric ball valve. In other embodiments, the first control valve 2 can also be a solenoid valve, etc., as long as it can play the role of adjusting the flow rate and throttling.

[0054] The air conditioning system further includes a driving module. The refrigerant radiator 3 is disposed in contact with the driving module, and a refrigerant flow path is provided in the refrigerant radiator 3. The refrigerant flow path is specifically arranged in a meandering shape or in a loop shape, so that the refrigerant can flow through all positions of the refrigerant radiator 3, ensuring the heat dissipation effect of the refrigerant radiator 3. The refrigerant radiator 3 is mainly used to dissipate heat from the driving module of the air conditioning system.

[0055] Regarding the installation position of the refrigerant radiator 3, it should be noted that although they are disposed in contact with each other in this embodiment, this is not a limitation of the present invention. On the premise of not deviating from the principle of the present invention, in other embodiments, a heat conducting sheet can also be provided between the two to make them spaced apart; or they are spaced apart without a heat conducting sheet, and heat conduction is carried out through air; both can make the refrigerant radiator 3 dissipate heat from the driving module, which does not deviate from the basic principle of the present invention and will fall within the protection scope of the present invention.

[0056] The driving module is a frequency converter for driving the compressor 6 to increase and decrease the frequency, and it includes power devices. During the operation of the compressor 6, the power module generates heat, and the refrigerant radiator 3 is used to dissipate heat from the power module.

[0057] The air conditioning system further includes a control module; both the first control valve 2 and the third control valve 4 are communicatively connected to the control module. The control module can control the opening degree of the first control valve 2 to control the refrigerant flow rate flowing through the first control valve 2. The control module can also control the opening degree of the third control valve 4, thereby controlling the throttling flow rate of the third control valve 4.

[0058] The driving module is communicatively connected to the control module, and the control module can control the driving module according to the target condition of the air conditioning system to adjust the frequency of the compressor 6.

[0059] The air conditioning system further includes a first temperature detector 11 and a second temperature detector. The first temperature detector 11 is arranged on one side of the refrigerant radiator 3 close to the first control valve 2 and is used to detect the temperature of the refrigerant flowing into or out of the refrigerant radiator 3. Specifically arranged inside the refrigerant pipeline, it can accurately detect the temperature of the refrigerant. Regarding the installation position of the first temperature detector 11, it should be noted that although in this embodiment, it is arranged inside the refrigerant pipeline, this is not a limitation of the present invention. On the premise of not deviating from the principle of the present invention, in other embodiments, the first temperature detector 11 can be arranged in the interface on one side of the refrigerant radiator 3 close to the first control valve 2, and it can also detect the temperature of the refrigerant flowing into or out of the refrigerant radiator 3. These do not deviate from the basic principle of the present invention and will fall within the protection scope of the present invention.

[0060] In this embodiment, the first temperature detector 11 is specifically a temperature sensor. In other embodiments, it can also be a thermometer, etc., as long as it can detect the temperature of the refrigerant.

[0061] The second temperature detector is arranged at the drive module and is used to detect the temperature of the drive module. Specifically, the second temperature detector is arranged inside the power module, which can enable the second temperature detector to accurately detect the temperature of the drive module, so as to control the flow rate of the refrigerant in the refrigerant radiator 3, and further control the temperature of the drive module. In this embodiment, the second temperature detector is specifically a temperature sensor. In other embodiments, it can also be a thermometer, etc., as long as it can detect the temperature of the refrigerant.

[0062] Both the first temperature detector 11 and the second temperature detector are communicatively connected to the control module. The temperature information detected by the first temperature detector 11 and the second temperature detector can be transmitted to the control module, so that the control module can adjust the flow rate of the refrigerant flowing through the refrigerant radiator 3, and further ensure that the refrigerant radiator 3 can effectively cool and dissipate heat for the control module.

[0063] The air conditioning system further includes a compressor 6 and a four-way valve 8. The suction port of the compressor 6 is connected to the first interface of the four-way valve 8, and the discharge port is connected to the second interface of the four-way valve 8; the side of the outdoor heat exchanger 1 far from the first control valve 2 is connected to the third interface of the four-way valve 8, and the side of the indoor heat exchanger 5 far from the third control valve 4 is connected to the fourth interface of the four-way valve 8; by changing the state of the four-way valve 8, the working mode of the air conditioning system is switched. The four-way valve 8 is communicatively connected to the control module, and the control module controls the state of the four-way valve 8, and further controls the working mode of the air conditioning system.

[0064] In addition, the air-conditioning system further includes a gas-liquid separator 7. The inlet of the gas-liquid separator 7 is connected to the first interface of the four-way valve 8, and the exhaust port of the gas-liquid separator 7 is connected to the suction port of the compressor 6. The gaseous refrigerant discharged from the gas-liquid separator 7 is sucked by the compressor 6. The liquid refrigerant flowing into the gas-liquid separator 7 is separated and remains in the gas-liquid separator 7. Under the action of the gaseous refrigerant, the liquid refrigerant in the gas-liquid separator 7 will vaporize and then be sucked by the compressor 6.

[0065] The air-conditioning system further includes a gas-side stop valve 9 and a liquid-side stop valve 10. The gas-side stop valve 9 is disposed between the fourth interface and the indoor heat exchanger 5. The liquid-side stop valve 10 is disposed between the indoor heat exchanger 5 and the third control valve 4.

[0066] In order to better achieve environmental protection, the refrigerant filled in the air-conditioning system is mostly a flammable refrigerant. When refrigerant leakage occurs on the side of the indoor heat exchanger 5, by closing the gas-side stop valve 9 and the liquid-side stop valve 10, the refrigerant leakage on the sides of the outdoor heat exchanger 1 and the compressor 6 can be effectively avoided, thereby ensuring safety; in addition, the amount of refrigerant filled during re-filling can be reduced, and the maintenance cost can be reduced. When refrigerant leakage occurs on the side of the outdoor heat exchanger 1, by closing the gas-side stop valve 9 and the liquid-side stop valve 10, the refrigerant leakage on the side of the indoor heat exchanger 5 can be effectively avoided, thereby ensuring safety; in addition, the amount of refrigerant filled during re-filling can be reduced, and the maintenance cost can be reduced.

[0067] The second control valve 13 is bypassed between the refrigerant radiator 3 and the first control valve 2. The second control valve 13 is configured to only allow the refrigerant to flow from the side away from the outdoor heat exchanger 1 to the outdoor heat exchanger 1. The second control valve 13 is specifically a check valve, which only allows the refrigerant to flow from the refrigerant radiator 3 to the outdoor heat exchanger 1.

[0068] Regarding the second control valve 13, it should be noted that although in this embodiment it is a check valve, this is not a limitation of the present invention. Without departing from the principle of the present invention, in other embodiments, it can also be an electric ball valve or a solenoid valve, etc. In the refrigeration mode, the second control valve 13 is closed, and in the heating mode, the second control valve 13 is opened. The second control valve 13 can achieve only allowing the refrigerant to flow from the refrigerant radiator 3 to the outdoor heat exchanger 1.

[0069] The air conditioning system further includes a fourth control valve 12, which is arranged in parallel with the refrigerant radiator 3 and the third control valve 4. Moreover, the first temperature detector 11 is also within the bypass range of the fourth control valve 12, that is, when the fourth control valve 12 is in parallel with the refrigerant radiator 3 and the third control valve 4, the refrigerant flowing to the fourth control valve 12 does not flow through the first temperature detector 11; when the fourth control valve 12 is in series with the refrigerant radiator 3, the refrigerant flowing through the fourth control valve 12 to the refrigerant radiator 3 flows through the first temperature detector 11. The fourth control valve 12 is specifically an electronic expansion valve; in other embodiments, the third control valve 4 can also be a thermal expansion valve or a two-way throttle valve, etc., as long as it can play the role of regulating the flow rate and throttling.

[0070] In the refrigeration mode, the first interface and the fourth interface of the four-way valve 8 are connected, and the second interface and the third interface are connected; the high-temperature and high-pressure refrigerant flowing out of the compressor 6 flows to the outdoor heat exchanger 1 after passing through the second interface and the third interface, exchanges heat in the outdoor heat exchanger 1, then flows to the refrigerant heat exchanger through the first control valve 2, and then flows out of the refrigerant heat exchanger and through the third control valve 4 and the liquid-side stop valve 10 to the indoor heat exchanger 5 for heat exchange to perform refrigeration. After flowing out of the indoor heat exchanger 5, it flows back to the compressor 6 through the gas-side stop valve 9, the first interface and the fourth interface of the four-way valve 8, and the gas-liquid separator 7 for compression again. In addition, in the refrigeration mode, the opening degree of the electronic expansion valve can be adjusted according to the load of the air conditioning system, so that the refrigerant flowing out of the first control valve 2 flows to the indoor heat exchanger 5 through two parallel branches.

[0071] In the heating mode, the first control valve 2 is closed; the second interface and the fourth interface of the four-way valve 8 are connected, and the first interface and the third interface are connected; the high-temperature and high-pressure refrigerant flowing out of the compressor 6 flows through the second interface and the fourth interface, and then flows through the gas-side stop valve 9 to the indoor heat exchanger 5 for heat exchange to heat the room. The refrigerant flowing out of the indoor heat exchanger 5 flows through the liquid-side stop valve 10 to the electronic expansion valve, then flows through the refrigerant radiator 3, and then flows through the second control valve 13 to the outdoor heat exchanger 1 for heat exchange. After flowing out of the outdoor heat exchanger 1, it flows back to the compressor 6 through the first interface and the third interface of the four-way valve 8 and the gas-liquid separator 7 for compression again.

[0072] In the defrosting mode, it operates according to the heating mode before the defrosting mode and then switches to the flow mode of the refrigeration mode for defrosting. At this time, only the refrigerant flows, but the outdoor fan and the indoor fan do not operate. The non-operation of the outdoor fan can accelerate the defrosting of the outdoor heat exchanger 1; the non-operation of the indoor fan can ensure that the impact on the indoor temperature is small, thereby ensuring the user experience.

[0073] The control module is further configured to be able to execute the control method of the air conditioning system, such as Figure 2As shown, the control method includes the following main steps:

[0074] S1. Obtain the working mode of the air conditioning system and the dew point temperature of the ambient air; the dew point temperature varies with the ambient temperature and ambient humidity. A temperature sensor and a humidity sensor are provided at the outdoor unit, and the control module calculates the dew point temperature based on the detected ambient temperature and ambient humidity. The dew point temperature is lower than the ambient temperature.

[0075] S2. According to the working mode and the dew point temperature, control the opening degrees of the first control valve 2 and / or the fourth control valve 12 to control the refrigerant temperature at the inlet of the refrigerant radiator 3.

[0076] Among them, step S2 "According to the working mode and the dew point temperature, control the opening degrees of the first control valve 2 and / or the fourth control valve 12 to control the refrigerant temperature at the inlet of the refrigerant radiator 3" specifically includes the following detailed steps:

[0077] In the refrigeration mode, adjust the opening degrees of the first control valve 2 and / or the fourth control valve 12 so that the refrigerant temperature at the inlet of the refrigerant radiator 3 is between the first preset dew point temperature and the temperature of the drive module, where the first preset dew point temperature is lower than the temperature of the drive module.

[0078] The temperature of the drive module is much higher than the ambient temperature, and the dew point temperature is only slightly lower than the ambient temperature. Among them, in the maximum load state of the air conditioning system, the maximum temperature difference between the inlet and outlet of the refrigerant radiator 3 is δT.

[0079] The first preset dew point temperature is determined according to the dew point temperature and δT. Specifically, the first preset dew point temperature is not less than the dew point temperature and not greater than the dew point temperature + δT; preferably, the first preset dew point temperature = the dew point temperature + δT; and controlling the refrigerant temperature at the inlet to be as close as possible to the first preset dew point temperature can keep the temperature of the refrigerant radiator 3 in a relatively low state, which can ensure effective heat dissipation for the drive module. By the refrigerant inlet temperature of the above temperature, while reducing the temperature of the electronic control drive module, it can effectively prevent condensation on the surface of the electronic control drive module under various operating conditions of the air conditioner; when the amount of cold required for the lower temperature of the drive module is small, since the first preset dew point temperature is higher than the dew point temperature, it can ensure that condensation will not occur on the surface of the drive module. Moreover, even if the inlet refrigerant temperature fluctuates and decreases, it is not easy to generate condensation.

[0080] In addition, in the refrigeration mode, when the load of the air conditioning system is greater than the preset load, the fourth control valve 12 is controlled to close, and the opening degree of the first control valve 2 is adjusted to throttle the refrigerant flowing to the refrigerant radiator 3, so that the refrigerant temperature at the inlet of the refrigerant radiator 3 is between the first preset dew point temperature and the temperature of the drive module; the throttling of the indoor heat exchanger 5 is achieved through the adjustment of the third control valve 4. The load of the air conditioning system being greater than the preset load means that it is a high-load mode at this time. At this time, the drive module generates more heat and the refrigerant radiator 3 requires a higher flow rate. After closing the electronic expansion valve, all the refrigerant flows through the refrigerant radiator 3, which can enhance the heat dissipation capacity of the refrigerant radiator 3. At this time, the refrigerant flow rate required for the air conditioning system to refrigerate is adjusted by the third control valve 4. At this time, when the refrigerant temperature at the inlet of the refrigerant radiator 3 is too high, it is necessary to reduce the opening degree of the first control valve 2 to lower the refrigerant temperature at the inlet of the refrigerant radiator 3; when the refrigerant temperature at the inlet of the refrigerant radiator 3 is too low, it is necessary to increase the opening degree of the first control valve 2 to increase the refrigerant temperature at the inlet of the refrigerant radiator 3; so as to keep the temperature at the inlet of the refrigerant radiator 3 within a suitable temperature range.

[0081] In the refrigeration mode, when the load of the air conditioning system is not greater than the preset load, the opening degrees of the first control valve 2 and the fourth control valve 12 are adjusted. The adjustment of the first control valve 2 can throttle the refrigerant flowing to the refrigerant radiator 3, so that the refrigerant temperature at the inlet of the refrigerant radiator 3 is between the first preset dew point temperature and the temperature of the drive module. The load of the air conditioning system not being greater than the preset load means that it is a low-load mode at this time. At this time, the drive module does not generate much heat and the refrigerant radiator 3 does not require a very high flow rate. The fourth control valve 12 can divert the refrigerant to reduce the amount of refrigerant flowing through the refrigerant radiator 3 and avoid the phenomenon of condensation on the surface of the drive module due to a large refrigerant flow rate in the refrigerant radiator 3. At this time, the opening degree of the fourth control valve 12 is determined according to the operating conditions of the air conditioning system, and after determination, when the operating conditions remain unchanged, the opening degree of the fourth control valve 12 remains unchanged; the specific opening degree of the fourth control valve 12 can be determined through experiments and then pre-stored in the system and called at any time during use. When the refrigerant temperature at the inlet of the refrigerant radiator 3 is too high, it is necessary to reduce the opening degree of the first control valve 2 to lower the refrigerant temperature at the inlet of the refrigerant radiator 3; when the refrigerant temperature at the inlet of the refrigerant radiator 3 is too low, it is necessary to increase the opening degree of the first control valve 2 to increase the refrigerant temperature at the inlet of the refrigerant radiator 3; so as to keep the temperature at the inlet of the refrigerant radiator 3 within a suitable temperature range.

[0082] Among them, step S2, "According to the working mode and the dew point temperature, control the opening degrees of the first control valve 2 and / or the fourth control valve 12 to control the refrigerant temperature at the inlet of the refrigerant radiator 3" specifically further includes the following detailed steps:

[0083] In the heating mode, the first control valve 2 is closed, and the opening degree of the fourth control valve 12 is adjusted to throttle the refrigerant flowing to the refrigerant radiator 3, so that the temperature of the refrigerant at the inlet of the refrigerant radiator 3 is greater than the second preset dew point temperature; preferably in this embodiment, the temperature of the refrigerant at the inlet of the refrigerant radiator 3 is between the second preset dew point temperature and the temperature of the drive module, where the second preset dew point temperature is lower than the temperature of the drive module. The inlet refrigerant temperature being higher than the second preset dew point temperature prevents the temperature of the refrigerant radiator 3 from being lower than the second preset dew point temperature. Since the refrigerant radiator 3 dissipates heat for the drive module, the temperature of the drive module will not be lower than the temperature of the refrigerant radiator 3, that is, the temperature of the drive module will be higher than the second preset dew point temperature, thereby ensuring that condensation will not occur on the drive module. Moreover, the outlet temperature of the refrigerant radiator 3 is lower than the temperature of the drive module, which can ensure the heat dissipation effect on the drive module.

[0084] Specifically, when the temperature of the refrigerant at the inlet of the refrigerant radiator 3 is too high, it is necessary to reduce the opening degree of the fourth control valve 12 to lower the temperature of the refrigerant at the inlet of the refrigerant radiator 3; when the temperature of the refrigerant at the inlet of the refrigerant radiator 3 is too low, it is necessary to increase the opening degree of the fourth control valve 12 to increase the temperature of the refrigerant at the inlet of the refrigerant radiator 3; so that the temperature at the inlet of the refrigerant radiator 3 is maintained within a suitable temperature range.

[0085] Among them, the second preset dew point temperature is determined according to the dew point temperature and δT. Specifically, the second preset dew point temperature is not less than the dew point temperature and not greater than the dew point temperature + δT; preferably, the second preset dew point temperature = dew point temperature + δT. Moreover, controlling the inlet refrigerant temperature to be as close as possible to the second preset dew point temperature can keep the temperature of the refrigerant radiator 3 in a relatively low state, which can ensure effective heat dissipation for the drive module. By the above inlet refrigerant temperature, while reducing the temperature of the electric control drive module, it can effectively prevent condensation from occurring on the surface of the electric control drive module under various operating conditions of the air conditioner; when the amount of cold required for the relatively low temperature of the drive module is small, since the second preset dew point temperature is higher than the dew point temperature, it can ensure that condensation will not occur on the surface of the drive module. Moreover, even if the inlet refrigerant temperature fluctuates and decreases, it is not easy to generate condensation.

[0086] Among them, step S2 "controlling the opening degrees of the first control valve 2 and / or the fourth control valve 12 according to the working mode and the dew point temperature to control the temperature of the refrigerant at the inlet of the refrigerant radiator 3" specifically further includes the following detailed steps:

[0087] In the defrosting mode: Before the defrosting mode is switched, in the heating mode, the first control valve 2 is closed, and the opening degree of the fourth control valve 12 is adjusted to throttle the refrigerant flowing to the refrigerant radiator 3, so that the temperature of the refrigerant at the inlet of the refrigerant radiator 3 is greater than the third preset dew point temperature; then it is switched to the cooling mode for defrosting. In this embodiment, preferably, the temperature of the refrigerant at the inlet of the refrigerant radiator 3 is controlled between the third preset dew point temperature and the temperature of the driving module, where the third preset dew point temperature is lower than the temperature of the driving module.

[0088] The temperature of the inlet refrigerant is higher than the third preset dew point temperature, so that the temperature of the refrigerant radiator 3 will not be lower than the third preset dew point temperature. Since the refrigerant radiator 3 dissipates heat for the driving module, the temperature of the driving module will not be lower than the temperature of the refrigerant radiator 3, which can ensure that the temperature of the driving module will be lower than the third preset dew point temperature, and thus it can be ensured that the driving module will not generate condensation. Moreover, the inlet temperature of the refrigerant radiator 3 is lower than the temperature of the driving module, which can ensure the heat dissipation effect on the driving module.

[0089] Among them, the third preset dew point temperature is determined according to the dew point temperature and δT. Specifically, the third preset dew point temperature is not less than the dew point temperature and not greater than the dew point temperature + δT; preferably, the third preset dew point temperature = the dew point temperature + δT. Moreover, controlling the temperature of the inlet refrigerant to be as close as possible to the third preset dew point temperature can keep the temperature of the refrigerant radiator 3 in a relatively low state, which can ensure effective heat dissipation for the driving module. By the above-mentioned inlet refrigerant temperature, while reducing the temperature of the electric control driving module, it can effectively prevent condensation from occurring on the surface of the electric control driving module under various operating conditions of the air conditioner; when the amount of cold required for the lower temperature of the driving module is less, since the third preset dew point temperature is higher than the dew point temperature, it can be ensured that condensation will not occur on the surface of the driving module. Moreover, even if the inlet refrigerant temperature fluctuates and decreases, it is not easy to generate condensation.

[0090] After the air conditioning system is switched to the cooling mode for defrosting, at the initial stage of defrosting, the fourth control valve 12 is closed, and the opening degree of the first control valve 2 is adjusted to throttle the refrigerant flowing to the refrigerant radiator 3, so that the temperature of the refrigerant at the inlet of the refrigerant radiator 3 is greater than the fourth preset dew point temperature and less than the fourth preset dew point temperature + preset temperature difference; since at the initial stage of defrosting, the amount of frost on the outdoor heat exchanger 1 is large, a large refrigerant flow rate is required to achieve rapid defrosting. At this time, the load of the compressor 6 is large, and the driving module generates more heat, and a large refrigerant flow rate is required to achieve cooling and temperature reduction of the driving module. Therefore, the fourth control valve 12 is closed, so that the refrigerant all flows through the refrigerant radiator 3.

[0091] The fourth preset dew point temperature is determined based on the dew point temperature and δT. Specifically, the fourth preset dew point temperature is not less than the dew point temperature and not greater than the dew point temperature + δT; preferably, the fourth preset dew point temperature = the dew point temperature + δT; moreover, controlling the refrigerant temperature at the inlet to be as close as possible to the fourth preset dew point temperature can keep the temperature of the refrigerant radiator 3 in a relatively low state, which can ensure effective heat dissipation for the drive module.

[0092] In the later stage of defrosting, adjust the opening degrees of the first control valve 2 and the fourth control valve 12 so that the refrigerant temperature at the inlet of the refrigerant radiator 3 is greater than the fourth preset dew point temperature and less than the fourth preset dew point temperature + the preset temperature difference; where the fourth preset dew point temperature is lower than the temperature of the drive module. And controlling the refrigerant temperature at the inlet to be as close as possible to the fourth preset dew point temperature can keep the temperature of the refrigerant radiator 3 in a relatively low state, which can ensure effective heat dissipation for the drive module; and can keep the drive module at a lower temperature. In addition, because the drive module is kept at a lower temperature and the refrigerant radiator 3 is also kept at a lower temperature; however, the temperature of the drive module is higher than the dew point temperature of the ambient air.

[0093] During the process of switching from the defrosting mode to the heating mode, even if the temperature of the drive module changes greatly and generates less heat, since the temperature of the refrigerant heat dissipation module is greater than the fourth preset dew point temperature and also greater than the ambient air temperature; at this time, the refrigerant radiator 3 will not cool the temperature of the drive module to below the fourth preset dew point temperature, so it can ensure that condensation will not occur on the surface of the drive module.

[0094] Since in the later stage of defrosting, the amount of frost on the outdoor heat exchanger 1 is less, less refrigerant flow is required to achieve rapid defrosting. At this time, the load of the compressor 6 is small, and the heat generated by the drive module is small, and less refrigerant flow is required to cool down the drive module. Therefore, the fourth control valve 12 opens for diversion so that less refrigerant flows through the refrigerant radiator 3. At this time, the opening degree of the fourth control valve 12 is determined according to the operating conditions of the air conditioning system, and after determination, when the operating conditions remain unchanged, the opening degree of the fourth control valve 12 remains unchanged; the specific opening degree of the fourth control valve 12 can be determined through experiments and then pre-stored in the system for calling at any time during use. When the refrigerant temperature at the inlet of the refrigerant radiator 3 is too high, it is necessary to reduce the opening degree of the first control valve 2 to lower the refrigerant temperature at the inlet of the refrigerant radiator 3; when the refrigerant temperature at the inlet of the refrigerant radiator 3 is too low, it is necessary to increase the opening degree of the first control valve 2 to increase the refrigerant temperature at the inlet of the refrigerant radiator 3.

[0095] In addition, the division between the early defrosting stage and the late defrosting stage is based on the defrosting time. When just entering the defrosting mode, it works according to the mode of the early defrosting stage. After a preset defrosting duration, it switches to the working mode of the late defrosting stage. The preset defrosting duration is determined according to the frost amount on the outdoor heat exchanger 1. When the frost amount is larger, the preset defrosting duration is longer; when the frost amount is smaller, the preset defrosting duration is shorter. Specifically, it can be determined according to experiments, or can be determined through simulation experiments and regression analysis.

[0096] As Figure 3 shown, the control method of this air conditioning system specifically includes the following detailed steps:

[0097] S01. Obtain the working mode of the air conditioning system;

[0098] S02. Determine whether the working mode is the cooling mode; if so, proceed to step S03; if not, proceed to step S06;

[0099] S03. Determine whether the load of the air conditioning system is greater than the preset load; if so, proceed to step S04; if not, proceed to step S05;

[0100] S04. The fourth control valve 12 is closed, and the opening degree of the first control valve 2 is adjusted to make the refrigerant temperature at the inlet of the refrigerant radiator 3 between the first preset dew point temperature and the temperature of the drive module;

[0101] S05. Adjust the opening degrees of the first control valve 2 and the fourth control valve 12 to make the refrigerant temperature at the inlet of the refrigerant radiator 3 between the first preset dew point temperature and the temperature of the drive module;

[0102] S06. Determine whether the working mode is the heating mode; if so, proceed to step S07; if not, proceed to step S08;

[0103] S07. Adjust the opening degree of the fourth control valve 12 to make the refrigerant temperature at the outlet of the refrigerant radiator 3 between the second preset dew point temperature and the temperature of the drive module;

[0104] S08. Determine whether the working mode is the defrosting mode; if so, proceed to step S09;

[0105] S09. Before the defrosting mode is switched, when in the heating mode, adjust the opening degree of the fourth control valve 12 to make the refrigerant temperature at the outlet of the refrigerant radiator 3 greater than the third preset dew point temperature; then switch to the cooling mode for defrosting; then proceed to step S010;

[0106] S010. The fourth control valve 12 is closed, and the opening degree of the first control valve 2 is adjusted so that the refrigerant temperature at the inlet of the refrigerant radiator 3 is greater than the fourth preset dew point temperature and less than the fourth preset dew point temperature + preset temperature difference; step S011 is performed after operating for a preset defrosting duration.

[0107] S011. Adjust the opening degrees of the first control valve 2 and the fourth control valve 12 so that the refrigerant temperature at the inlet of the refrigerant radiator 3 is greater than the fourth preset dew point temperature and less than the fourth preset dew point temperature + preset temperature difference.

[0108] Embodiment 2

[0109] This embodiment discloses a control method for an air-conditioning system, which is basically the same as the control method for the air-conditioning system in Embodiment 1, except for the control of the inlet refrigerant temperature in the refrigeration mode.

[0110] Among them, step S2 "control the opening degrees of the first control valve 2 and / or the fourth control valve 12 according to the working mode of the air-conditioning system and the dew point temperature of the ambient air to control the refrigerant temperature at the inlet of the refrigerant radiator 3" specifically includes:

[0111] In the refrigeration mode, adjust the opening degrees of the first control valve 2 and / or the fourth control valve 12 so that the refrigerant temperature at the inlet of the refrigerant radiator 3 is between the ambient temperature and the dew point temperature, where the ambient temperature is higher than the dew point temperature.

[0112] The temperature of the driving module is much higher than the ambient temperature, and the dew point temperature is only slightly lower than the ambient temperature. Controlling the refrigerant temperature at the inlet of the refrigerant radiator 3 between the ambient temperature and the dew point temperature can enable the refrigerant radiator 3 to effectively cool and dissipate heat from the driving module, and ensure that the temperature of the refrigerant radiator 3 does not fall below the dew point temperature, so that condensation does not occur on the driving module; in summary, it can not only ensure the heat dissipation effect of the driving module but also ensure the stability of the system. Specifically, when the refrigerant temperature at the inlet of the refrigerant radiator 3 is too high, the opening degree of the control valve needs to be reduced to lower the refrigerant temperature at the inlet of the refrigerant radiator 3; when the refrigerant temperature at the inlet of the refrigerant radiator 3 is too low, the opening degree of the control valve needs to be increased to increase the refrigerant temperature at the inlet of the refrigerant radiator 3; so that the temperature at the inlet of the refrigerant radiator 3 is maintained within a suitable temperature range.

[0113] Specifically, in the refrigeration mode, when the load of the air-conditioning system is greater than the preset load, the fourth control valve 12 is controlled to close, and the opening degree of the first control valve 2 is adjusted so that the refrigerant temperature at the inlet of the refrigerant radiator 3 is between the ambient temperature and the dew point temperature. When the load of the air-conditioning system is greater than the preset load, it represents a high-load mode at this time. At this time, the driving module generates more heat, and the refrigerant radiator 3 requires a higher flow rate. After closing the electronic expansion valve, all the refrigerant flows through the refrigerant radiator 3, which can enhance the heat dissipation capacity of the refrigerant radiator 3. At this time, the refrigerant flow rate required for the air-conditioning system to refrigerate is adjusted by the third control valve 4. At this time, when the refrigerant temperature at the inlet of the refrigerant radiator 3 is too high, it is necessary to reduce the opening degree of the first control valve 2 to lower the refrigerant temperature at the inlet of the refrigerant radiator 3; when the refrigerant temperature at the inlet of the refrigerant radiator 3 is too low, it is necessary to increase the opening degree of the first control valve 2 to increase the refrigerant temperature at the inlet of the refrigerant radiator 3; so that the temperature at the inlet of the refrigerant radiator 3 is maintained within a suitable temperature range.

[0114] In the refrigeration mode, when the load of the air-conditioning system is not greater than the preset load, the opening degrees of the first control valve 2 and the fourth control valve 12 are adjusted so that the refrigerant temperature at the inlet of the refrigerant radiator 3 is between the ambient temperature and the dew point temperature. When the load of the air-conditioning system is not greater than the preset load, it represents a low-load mode at this time. At this time, the driving module does not generate much heat, and the refrigerant radiator 3 does not require a very high flow rate. The fourth control valve 12 can divert the refrigerant to reduce the amount of refrigerant flowing through the refrigerant radiator 3 and avoid the phenomenon that the surface of the driving module generates condensation due to a large refrigerant flow rate in the refrigerant radiator 3. At this time, the opening degree of the fourth control valve 12 is determined according to the working conditions of the air-conditioning system, and after determination, when the working conditions remain unchanged, the opening degree of the fourth control valve 12 remains unchanged; the specific opening degree of the fourth control valve 12 can be determined through experiments and then pre-stored in the system and called at any time during use. When the refrigerant temperature at the inlet of the refrigerant radiator 3 is too high, it is necessary to reduce the opening degree of the first control valve 2 to lower the refrigerant temperature at the inlet of the refrigerant radiator 3; when the refrigerant temperature at the inlet of the refrigerant radiator 3 is too low, it is necessary to increase the opening degree of the first control valve 2 to increase the refrigerant temperature at the inlet of the refrigerant radiator 3; so that the temperature at the inlet of the refrigerant radiator 3 is maintained within a suitable temperature range.

[0115] Embodiment 3

[0116] As Figure 4 shown, this embodiment discloses an air-conditioning system, which is basically the same as the air-conditioning system in Embodiment 1, except that; the third control valve 4 in this embodiment is an electronic expansion valve, or a two-way throttle valve, a thermal expansion valve, etc. The fourth control valve 12 is specifically a throttle check valve and only allows the refrigerant to flow from the indoor heat exchanger 5 side to the refrigerant radiator 3.

[0117] In the control method of the air conditioning system, step S2 "control the opening degrees of the first control valve 2 and / or the fourth control valve 12 according to the working mode and the dew point temperature to control the refrigerant temperature at the inlet of the refrigerant radiator 3" specifically includes the following detailed steps:

[0118] In the cooling mode, adjust the opening degree of the first control valve 2 so that the refrigerant temperature at the inlet of the refrigerant radiator 3 is between the first preset dew point temperature and the temperature of the driving module, where the first preset dew point temperature is lower than the temperature of the driving module.

[0119] Step S2 "control the opening degrees of the first control valve 2 and / or the fourth control valve 12 according to the working mode and the dew point temperature to control the refrigerant temperature at the inlet of the refrigerant radiator 3" specifically further includes the following detailed steps:

[0120] In the heating mode, the first control valve 2 is closed, that is, the electronic expansion valve is closed, and the opening degree of the fourth control valve 12 is adjusted to throttle the refrigerant flowing to the refrigerant radiator 3 so that the refrigerant temperature at the inlet of the refrigerant radiator 3 is greater than the second preset dew point temperature; preferably in this embodiment, the refrigerant temperature at the inlet of the refrigerant radiator 3 is between the second preset dew point temperature and the temperature of the driving module, where the second preset dew point temperature is lower than the temperature of the driving module.

[0121] Step S2 "control the opening degrees of the first control valve 2 and / or the fourth control valve 12 according to the working mode and the dew point temperature to control the refrigerant temperature at the inlet of the refrigerant radiator 3" specifically further includes the following detailed steps:

[0122] In the defrosting mode: Before the defrosting mode is switched, in the heating mode, the first control valve 2 is closed, and the opening degree of the fourth control valve 12 is adjusted to throttle the refrigerant flowing to the refrigerant radiator 3 so that the refrigerant temperature at the inlet of the refrigerant radiator 3 is greater than the third preset dew point temperature; then switch to the cooling mode for defrosting. In this embodiment, preferably, the refrigerant temperature at the inlet of the refrigerant radiator 3 is controlled to be between the third preset dew point temperature and the temperature of the driving module, where the third preset dew point temperature is lower than the temperature of the driving module.

[0123] After the air conditioning system switches to the cooling mode for defrosting, during the defrosting process, the fourth control valve 12 is closed, and the opening degree of the first control valve 2 is adjusted to throttle the refrigerant flowing to the refrigerant radiator 3 so that the refrigerant temperature at the inlet of the refrigerant radiator 3 is greater than the fourth preset dew point temperature and less than the fourth preset dew point temperature + preset temperature difference.

[0124] Embodiment 4

[0125] As Figure 5As shown in the figure, this embodiment discloses an air-conditioning system, which has basically the same structure as the air-conditioning system in Embodiment 1, except that: the third control valve 4 in this embodiment is a one-way valve, which only allows the refrigerant to flow from the refrigerant radiator 3 to the indoor heat exchanger 5, etc. The fourth control valve 12 is specifically an electronic expansion valve. The control method in this embodiment is the same as the control method in Embodiment 1.

[0126] Embodiment 5

[0127] As Figure 6 shown in the figure, this embodiment discloses an air-conditioning system, which has basically the same structure as the air-conditioning system in Embodiment 1, except that: the third control valve 4 in this embodiment is a throttle check valve, and only allows the refrigerant to flow from the refrigerant radiator 3 to the indoor heat exchanger 5 side. The fourth control valve 12 is specifically a throttle check valve, and only allows the refrigerant to flow from the indoor heat exchanger 5 side to the refrigerant radiator 3.

[0128] In the control method of this air-conditioning system, step S2 "control the opening degrees of the first control valve 2 and / or the fourth control valve 12 according to the working mode and the dew point temperature to control the refrigerant temperature at the inlet of the refrigerant radiator 3" specifically includes the following detailed steps:

[0129] In the cooling mode, adjust the opening degree of the first control valve 2 so that the refrigerant temperature at the inlet of the refrigerant radiator 3 is between the first preset dew point temperature and the temperature of the driving module, where the first preset dew point temperature is lower than the temperature of the driving module.

[0130] Step S2 "control the opening degrees of the first control valve 2 and / or the fourth control valve 12 according to the working mode and the dew point temperature to control the refrigerant temperature at the inlet of the refrigerant radiator 3" specifically further includes the following detailed steps:

[0131] In the heating mode, adjust the opening degree of the fourth control valve 12 to throttle the refrigerant flowing to the refrigerant radiator 3 so that the refrigerant temperature at the inlet of the refrigerant radiator 3 is greater than the second preset dew point temperature; preferably in this embodiment, the refrigerant temperature at the inlet of the refrigerant radiator 3 is between the second preset dew point temperature and the temperature of the driving module, where the second preset dew point temperature is lower than the temperature of the driving module.

[0132] Step S2 "control the opening degrees of the first control valve 2 and / or the fourth control valve 12 according to the working mode and the dew point temperature to control the refrigerant temperature at the inlet of the refrigerant radiator 3" specifically further includes the following detailed steps:

[0133] In the defrosting mode: Before the defrosting mode is switched, when in the heating mode, adjust the opening degree of the fourth control valve 12 to throttle the refrigerant flowing to the refrigerant radiator 3, so that the temperature of the refrigerant at the inlet of the refrigerant radiator 3 is greater than the third preset dew point temperature; then switch to the cooling mode for defrosting. In this embodiment, preferably, control the temperature of the refrigerant at the inlet of the refrigerant radiator 3 between the third preset dew point temperature and the temperature of the driving module, where the third preset dew point temperature is lower than the temperature of the driving module.

[0134] After the air-conditioning system switches to the cooling mode for defrosting, during the defrosting process, adjust the opening degree of the first control valve 2 to throttle the refrigerant flowing to the refrigerant radiator 3, so that the temperature of the refrigerant at the inlet of the refrigerant radiator 3 is greater than the fourth preset dew point temperature and less than the fourth preset dew point temperature + preset temperature difference.

[0135] Embodiment Six

[0136] As Figure 7 shown, this embodiment discloses an air-conditioning system, which is basically the same as the air-conditioning system in Embodiment One, except that; the first control valve 2 in this embodiment is a throttle check valve, which only allows the refrigerant to flow from the outdoor heat exchanger 1 to the refrigerant radiator 3. The control method in this embodiment is the same as the control method in Embodiment One.

[0137] So far, the technical solution of the present invention has been described in conjunction with the preferred embodiments shown in the drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the protection scope of the present invention.

Claims

1. An air conditioning system, characterized in that, The air conditioning system includes an outdoor heat exchanger (1), a first control valve (2), a refrigerant radiator (3), a third control valve (4), and an indoor heat exchanger (5) connected in sequence; the refrigerant radiator (3) is used to dissipate heat from the drive module of the air conditioning system; the third control valve (4) only allows the refrigerant to flow from the refrigerant radiator (3) to the indoor heat exchanger (5); the air conditioning system further includes: A second control valve (13) is provided in parallel with the refrigerant radiator (3) and the first control valve (2), and the second control valve (13) is configured to only allow the refrigerant to flow from the side away from the outdoor heat exchanger (1) to the outdoor heat exchanger (1).

2. The air conditioning system according to claim 1, wherein, The air conditioning system further includes a fourth control valve (12) provided in parallel with the refrigerant radiator (3) and the third control valve (4).

3. The air conditioning system according to claim 1, wherein, The air conditioning system further includes a first temperature detector (11) provided on the side of the refrigerant radiator (3) close to the first control valve (2) for detecting the temperature of the refrigerant flowing into or out of the refrigerant radiator (3); and / or The air conditioning system further includes a second temperature detector provided at the drive module for detecting the temperature of the drive module.

4. A control method for an air conditioning system according to any one of claims 1-3, characterized in that, The control method includes: According to the working mode of the air conditioning system and the dew point temperature of the ambient air, controlling the opening degrees of the first control valve (2) and / or the fourth control valve (12) to control the temperature of the refrigerant at the inlet of the refrigerant radiator (3).

5. The air conditioning system according to claim 4, wherein "According to the working mode of the air conditioning system and the dew point temperature of the ambient air, controlling the opening degrees of the first control valve (2) and / or the fourth control valve (12) to control the temperature of the refrigerant at the inlet of the refrigerant radiator (3)" includes: In the cooling mode, adjusting the opening degrees of the first control valve (2) and / or the fourth control valve (12) so that the temperature of the refrigerant at the inlet of the refrigerant radiator (3) is between the ambient temperature and the dew point temperature, where the ambient temperature is higher than the dew point temperature; Preferably, in the cooling mode, when the load of the air conditioning system is greater than a preset load, controlling the fourth control valve (12) to close and adjusting the opening degree of the first control valve (2) so that the temperature of the refrigerant at the inlet of the refrigerant radiator (3) is between the ambient temperature and the dew point temperature; In the cooling mode, when the load of the air conditioning system is not greater than the preset load, adjusting the opening degrees of the first control valve (2) and the fourth control valve (12) so that the temperature of the refrigerant at the inlet of the refrigerant radiator (3) is between the ambient temperature and the dew point temperature.

6. The air conditioning system according to claim 4, wherein "According to the working mode of the air conditioning system and the dew point temperature of the ambient air, controlling the opening degrees of the first control valve (2) and / or the third control valve (4) to control the temperature of the refrigerant at the inlet of the refrigerant radiator (3)" includes: In the refrigeration mode, adjust the opening degrees of the first control valve (2) and / or the fourth control valve (12) so that the refrigerant temperature at the inlet of the refrigerant radiator (3) is between a first preset dew point temperature and the temperature of the drive module, where the first preset dew point temperature is lower than the temperature of the drive module; Preferably, in the refrigeration mode, when the load of the air conditioning system is greater than a preset load, control the fourth control valve (12) to close, and adjust the opening degree of the first control valve (2) so that the refrigerant temperature at the inlet of the refrigerant radiator (3) is between the first preset dew point temperature and the temperature of the drive module; In the refrigeration mode, when the load of the air conditioning system is not greater than the preset load, adjust the opening degrees of the first control valve (2) and the fourth control valve (12) so that the refrigerant temperature at the inlet of the refrigerant radiator (3) is between the first preset dew point temperature and the temperature of the drive module.

7. The air conditioning system according to claim 6, characterized in that, "According to the working mode of the air conditioning system and the dew point temperature of the ambient air, control the opening degrees of the first control valve (2) and / or the third control valve (4) to control the refrigerant temperature at the inlet of the refrigerant radiator (3)" includes: In the heating mode, the first control valve (2) is closed, and adjust the opening degree of the fourth control valve (12) so that the refrigerant temperature at the inlet of the refrigerant radiator (3) is greater than a second preset dew point temperature; Preferably, the refrigerant temperature at the inlet of the refrigerant radiator (3) is between the second preset dew point temperature and the temperature of the drive module, where the second preset dew point temperature is lower than the temperature of the drive module.

8. The air conditioning system according to claim 7, wherein, "According to the working mode of the air conditioning system and the dew point temperature of the ambient air, control the opening degrees of the first control valve (2) and / or the third control valve (4) to control the refrigerant temperature at the inlet of the refrigerant radiator (3)" includes: Before the defrosting mode is switched, in the heating mode, the first control valve (2) is closed, and adjust the opening degree of the fourth control valve (12) so that the refrigerant temperature at the inlet of the refrigerant radiator (3) is greater than a third preset dew point temperature; then switch to the refrigeration mode for defrosting; Preferably, the refrigerant temperature at the inlet of the refrigerant radiator (3) is between the third preset dew point temperature and the temperature of the drive module, where the third preset dew point temperature is lower than the temperature of the drive module.

9. The air conditioning system according to claim 8, characterized in that, When the air conditioning system is switched to the refrigeration mode for defrosting, at the initial stage of defrosting, the fourth control valve (12) is closed, and adjust the opening degree of the first control valve (2) so that the refrigerant temperature at the inlet of the refrigerant radiator (3) is greater than a fourth preset dew point temperature; where the fourth preset dew point temperature is lower than the temperature of the drive module; Preferably, adjust the opening degree of the first control valve (2) so that the refrigerant temperature at the inlet of the refrigerant radiator (3) is greater than the fourth preset dew point temperature and less than the fourth preset dew point temperature + a preset temperature difference; At the later stage of defrosting, adjust the opening degrees of the first control valve (2) and the fourth control valve (12) so that the refrigerant temperature at the inlet of the refrigerant radiator (3) is greater than the fourth preset dew point temperature; Preferably, adjust the opening degrees of the first control valve (2) and the fourth control valve (12) so that the refrigerant temperature at the inlet of the refrigerant radiator (3) is greater than the fourth preset dew point temperature and less than the fourth preset dew point temperature + preset temperature difference.

10. The air-conditioning system according to claim 9, characterized in that, In the maximum load state of the air conditioning system, the maximum temperature difference between the inlet and outlet of the refrigerant radiator (3) is δT; The first preset dew point temperature, the second preset dew point temperature, the third preset dew point temperature, and the fourth preset dew point temperature are all determined according to δT and the dew point temperature.

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