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 control valve, a refrigerant radiator, a throttling element and an indoor heat exchanger which are sequentially connected. The refrigerant radiator is used for radiating a driving module of the air conditioning system; the air conditioning system further comprises a first temperature detection piece which is arranged on the side, close to the control valve, of the refrigerant radiator and used for detecting the temperature of the refrigerant flowing to the refrigerant radiator or flowing out of the refrigerant radiator. The opening degree of the control valve is adjusted in the refrigeration mode, the opening degree of the throttling element is adjusted in the heating mode, and the temperature of the throttling element and the control valve is controlled in the defrosting mode, so that the temperature is higher than the dew point temperature and lower than the temperature of the driving module; therefore, the driving module can be cooled, and condensation can be avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of air conditioners, and specifically 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 be compatible with all working conditions of refrigeration and heating, and there are the following problems: First, in high-temperature working conditions, the heat dissipation effect of the refrigerant is poor, resulting in a high temperature of electrical components, insufficient compressor frequency, and poor high-temperature working condition effects. 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 and 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 effect 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 exchanges heat by coupling 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 opened. In the refrigeration mode of this technical solution, first, it is assisted by the electronic expansion valve to throttle within 20%; after passing through the refrigerant radiator, it is throttled by the one-way throttle valve again. Since the temperature and humidity change with the weather during the use of the air conditioner, the outdoor temperature working conditions change greatly, and in some cases, the piping changes during installation, and 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 the temperature is too high and 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 control valve, a refrigerant radiator, a throttling element, and an indoor heat exchanger connected in sequence; the refrigerant radiator is used to dissipate heat from the drive module of the air conditioning system;

[0007] The air conditioning system further includes a first temperature detector, which is arranged on one side of the refrigerant radiator close to the control valve and is used to detect the temperature of the refrigerant flowing into or out of the refrigerant radiator.

[0008] In a specific embodiment of the above air conditioning system, the air conditioning system further includes a compressor and a four-way valve. The suction port of the compressor is connected to the first interface of the four-way valve, and the discharge port is connected to the second interface of the four-way valve;

[0009] One side of the outdoor heat exchanger away from the control valve is connected to the third interface of the four-way valve, and one side of the indoor heat exchanger away from the throttling element is connected to the fourth interface of the four-way valve;

[0010] By changing the state of the four-way valve, the working mode of the air conditioning system is switched.

[0011] In a specific embodiment of the above air conditioning system, the air conditioning system further includes a second temperature detector, which is arranged at the drive module and is used to detect the temperature of the drive module.

[0012] 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:

[0013] According to the working mode of the air conditioning system and the dew point temperature of the ambient air, adjust the opening degrees of the control valve and / or the throttling element to control the refrigerant temperature at the inlet and outlet of the refrigerant radiator.

[0014] 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, adjust the opening degrees of the control valve and / or the throttling element to control the refrigerant temperature at the inlet and outlet of the refrigerant radiator" includes:

[0015] In the refrigeration mode, adjust the opening degree of the control valve so that the refrigerant temperature 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.

[0016] 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, adjust the opening degrees of the control valve and / or the throttling element to control the refrigerant temperature at the inlet and outlet of the refrigerant radiator" includes:

[0017] In the refrigeration mode, adjust the opening degree of the 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.

[0018] In a specific embodiment of the control method of the above air conditioning system, "adjust the opening degree of the control valve and / or the throttling element 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 and outlet of the refrigerant radiator" includes:

[0019] In the heating mode, adjust the opening degree of the throttling element so that the refrigerant temperature at the outlet of the refrigerant radiator is greater than the second preset dew point temperature;

[0020] Preferably, the refrigerant temperature at the outlet 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.

[0021] In a specific embodiment of the control method of the above air conditioning system, "adjust the opening degree of the control valve and / or the throttling element 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 and outlet of the refrigerant radiator" includes:

[0022] In the defrosting mode, before the defrosting mode is switched, when in the heating mode, adjust the opening degree of the throttling element so that the refrigerant temperature at the outlet of the refrigerant radiator is greater than the third preset dew point temperature; then switch to the refrigeration mode for defrosting.

[0023] Preferably, the refrigerant temperature at the outlet of the refrigerant radiator 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.

[0024] In a specific embodiment of the control method of the above air conditioning system, when the air conditioning system switches to the refrigeration mode for defrosting, adjust the opening degree of the control valve 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.

[0025] In a specific embodiment of the control method of the above air conditioning system, when the air conditioning system is in the maximum load state, the maximum temperature difference between the inlet and outlet of the refrigerant radiator is δT;

[0026] 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.

[0027] In the case of adopting the above technical solution, the air-conditioning system of the present invention includes an outdoor heat exchanger, a control valve, a refrigerant radiator, a throttling element, and an indoor heat exchanger connected in sequence; the refrigerant radiator is used to dissipate heat from the drive module of the air-conditioning system; the air-conditioning system further includes a first temperature detector, which is arranged on the side of the refrigerant radiator close to the control valve and is used to detect the temperature of the refrigerant flowing into or out of the refrigerant radiator.

[0028] In the refrigeration mode, by adjusting the opening degree of the control valve, the temperature of the refrigerant radiator can be controlled to be above the dew point temperature and lower than the temperature of the drive module; it can not only cool and dissipate heat from the drive module, but also ensure that no condensation occurs.

[0029] In the heating mode, by adjusting the opening degree of the throttling element, the temperature of the refrigerant radiator can be controlled to be above the dew point temperature and lower than the temperature of the drive module; it can not only cool and dissipate heat from the drive module, but also ensure that no condensation occurs.

[0030] In the defrosting mode, by controlling the temperature of the throttling element and the control valve, the temperature of the refrigerant radiator can be controlled to be above the dew point temperature and lower than the temperature of the drive module; it can not only cool and dissipate heat from the drive module, but also ensure that no condensation occurs. Description of the Drawings

[0031] The following describes the preferred embodiments of the present invention with reference to the drawings. In the drawings:

[0032] Figure 1 is a schematic structural diagram of the air-conditioning system provided by the present invention;

[0033] Figure 2 is a main step flow chart of the control method of the air-conditioning system provided by the present invention;

[0034] Figure 3 is a detailed step flow chart of the control method of the air-conditioning system provided by the present invention.

[0035] List of reference numerals: 1. Outdoor heat exchanger; 2. Control valve; 3. Refrigerant radiator; 4. Throttling element; 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. Detailed Embodiments

[0036] The following describes the preferred embodiments of the present invention with reference to the drawings. Those skilled in the art should understand that these embodiments 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.

[0037] It should be noted that in the description of the present invention, the terms indicating the direction or positional relationship such as "upper", "lower", "left", "right", "inner", "outer", etc. are based on the direction or positional relationship shown in the drawings. This is only for the 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. Therefore, it should not be construed as a limitation to the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0038] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and limited, 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.

[0039] In order to solve the problems that the existing refrigerant heat dissipation methods are prone to condensation and too high temperature, which is not conducive to heat dissipation.

[0040] As Figure 1 shown, this embodiment discloses an air conditioning system, which includes an outdoor heat exchanger 1, a control valve 2, a refrigerant radiator 3, a throttling element 4 and an indoor heat exchanger 5 connected in sequence.

[0041] In this embodiment, the throttling element 4 is specifically an electronic expansion valve; in other embodiments, the throttling element 4 can also be a thermal expansion valve or a two-way throttling valve, etc., as long as it can play the role of regulating the flow rate and throttling.

[0042] In this embodiment, the 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 of the electric ball valve. In other embodiments, the control valve 2 can also be a solenoid valve, etc., as long as it can play the role of regulating the flow rate and throttling.

[0043] This 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 a ring shape, so that the refrigerant can flow through each position 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.

[0044] Regarding the installation position of the refrigerant radiator 3, it should be noted that although they are attached to each other in this embodiment, this is not a limitation of the present invention. Without departing from the principle of the present invention, in other embodiments, a heat conducting sheet can be provided between them to space them apart; or there is no heat conducting sheet between them, and heat conduction is achieved through air; all of which can enable the refrigerant radiator 3 to dissipate heat from the drive module, and none of these depart from the basic principle of the present invention and will fall within the protection scope of the present invention.

[0045] The drive module is an inverter for driving the compressor 6 to increase or decrease its frequency, and it includes power devices. During the operation of the compressor 6, the power module will generate heat, and the refrigerant radiator 3 is used to dissipate heat from this power module.

[0046] This air-conditioning system further includes a control module; both the control valve 2 and the throttling element 4 are communicatively connected to the control module. The control module can control the opening degree of the control valve 2 to control the refrigerant flow rate flowing through the control valve 2. The control module can also control the opening degree of the throttling element 4, and further control the throttling flow rate of the throttling element 4.

[0047] Among them, the drive module is communicatively connected to the control module, and the control module can control the drive module according to the target condition of the air-conditioning system to adjust the frequency of the compressor 6.

[0048] The air-conditioning system further includes a first temperature detector 11 and a second temperature detector. Among them, the first temperature detector 11 is arranged on the side of the refrigerant radiator 3 close to the control valve 2, and is used to detect the temperature of the refrigerant flowing into or out of the refrigerant radiator 3. Specifically, it is arranged inside the refrigerant pipeline, and the temperature of the refrigerant can be accurately detected. 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. Without departing from the principle of the present invention, in other embodiments, the first temperature detector 11 can be arranged in the interface on the side of the refrigerant radiator 3 close to the control valve 2, and it can also detect the temperature of the refrigerant flowing into or out of the refrigerant radiator 3. None of these depart from the basic principle of the present invention and will fall within the protection scope of the present invention.

[0049] 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.

[0050] The second temperature detector is arranged at the driving module for detecting the temperature of the driving 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 driving module, so as to control the flow rate of the refrigerant in the refrigerant radiator 3, and further control the temperature of the driving 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.

[0051] 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 from the control module.

[0052] 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 away from the control valve 2 is connected to the third interface of the four-way valve 8, and the side of the indoor heat exchanger 5 away from the throttling element 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.

[0053] 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 discharge 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.

[0054] 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 arranged between the fourth interface and the indoor heat exchanger 5. In this embodiment, the liquid-side stop valve 10 is arranged between the indoor heat exchanger 5 and the throttling element 4. In other embodiments, the liquid-side stop valve 10 can also be arranged between the throttling element 4 and the refrigerant radiator 3.

[0055] In order to better achieve environmental protection, the refrigerant filled in the air-conditioning system is mostly 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, thus ensuring safety; in addition, the refrigerant filling volume 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, thus ensuring safety; in addition, the refrigerant filling volume during re-filling can be reduced, and the maintenance cost can be reduced.

[0056] 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 through the second interface and the third interface and then flows to the outdoor heat exchanger 1. After heat exchange in the outdoor heat exchanger 1, it flows through the control valve 2 to the refrigerant heat exchanger, and then after flowing out of the refrigerant heat exchanger, it flows through the throttling element 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.

[0057] In the heating mode, 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 outdoor heat exchanger 1 for heat exchange in the indoor heat exchanger 5 to heat the indoor space. The refrigerant flowing out of the indoor heat exchanger 5 flows through the liquid-side stop valve 10 and then to the electronic expansion valve, and then flows through the refrigerant heat exchange and the control valve 2, and then flows 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.

[0058] In the defrosting mode, it operates according to the heating mode before defrosting, 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, thus ensuring the user experience.

[0059] The control module is also configured to be able to execute the control method of the air-conditioning system, such as Figure 2 shown, the control method includes the following main steps:

[0060] S1. Obtain the operating 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 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 humidity. The dew point temperature is lower than the ambient temperature.

[0061] S2. According to the operating mode and the dew point temperature, control the opening degree of the control valve 2 and / or the throttling element 4 to control the refrigerant temperature at the inlet and outlet of the refrigerant radiator 3.

[0062] Among them, step S2, "According to the operating mode and the dew point temperature, control the opening degree of the control valve 2 and / or the throttling element 4 to control the refrigerant temperature at the inlet and outlet of the refrigerant radiator 3", specifically includes the following detailed steps:

[0063] In the cooling mode, adjust the opening degree of the control valve 2 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 ambient temperature and the dew point temperature. The temperature control of the indoor heat exchanger 5 is achieved by adjusting the opening degree of the throttling element 4.

[0064] 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. 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 drive module, and prevent the temperature of the refrigerant radiator 3 from being lower than the dew point temperature, thereby preventing the drive module from generating condensation; in summary, it can not only ensure the heat dissipation effect of the drive 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, it is necessary to reduce the opening degree of the 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 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.

[0065] 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.

[0066] Regarding the refrigerant temperature at the inlet of the refrigerant radiator 3 in the refrigeration mode, it should be noted that although in this embodiment, the inlet refrigerant temperature is between the ambient temperature and the dew point temperature; this is not a limitation of the present invention. Without departing from the principle of the present invention, in other embodiments, those skilled in the art can choose to adjust the opening degree of the control valve 2 in the refrigeration mode 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. 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 using the refrigerant inlet temperature of the above temperature, while reducing the temperature of the electric control drive module, condensation can be effectively prevented from occurring on the surface of the electric control drive module under various operating conditions of the air conditioner; when the amount of cooling required for the relatively low temperature of the drive module is small, since the first 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 drive module. Moreover, even if the inlet refrigerant temperature fluctuates and decreases, it is not easy to generate condensation. These all do not depart from the basic principle of the present invention and will fall within the protection scope of the present invention.

[0067] Among them, step S2 "controlling the opening degrees of the control valve 2 and / or the throttling element 4 according to the working mode and the dew point temperature to control the refrigerant temperatures at the inlet and outlet of the refrigerant radiator 3" specifically further includes the following detailed steps:

[0068] In the heating mode, adjust the opening degree of the throttling element 4 to throttle the refrigerant flowing to the refrigerant radiator 3 so that the refrigerant temperature at the outlet of the refrigerant radiator 3 is greater than the second preset dew point temperature; the temperature adjustment of the outdoor heat exchanger 1 is achieved by adjusting the opening degree of the control valve 2. Preferably in this embodiment, the refrigerant temperature at the outlet 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 refrigerant temperature at the outlet is higher than the second preset dew point temperature, that is, the temperature of the refrigerant radiator 3 after heat exchange is higher than the second preset dew point temperature, and the temperature of the refrigerant radiator 3 will not be 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 being lower than the temperature of the drive module can ensure the heat dissipation effect on the drive module.

[0069] Specifically, when the refrigerant temperature at the outlet of the refrigerant radiator 3 is too high, it is necessary to reduce the opening degree of the throttling element 4 to lower the refrigerant temperature at the outlet of the refrigerant radiator 3; when the refrigerant temperature at the outlet of the refrigerant radiator 3 is too low, it is necessary to increase the opening degree of the throttling element 4 to increase the refrigerant temperature at the outlet of the refrigerant radiator 3; so as to keep the temperature at the outlet of the refrigerant radiator 3 within a suitable temperature range.

[0070] 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 = the dew point temperature + δT. Moreover, controlling the refrigerant temperature at the outlet 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-mentioned outlet 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 when the inlet refrigerant temperature fluctuates and decreases, it is not easy to generate condensation.

[0071] Among them, step S2 "control the opening degrees of the control valve 2 and / or the throttling element 4 according to the working mode and the dew point temperature to control the refrigerant temperature at the inlet and outlet of the refrigerant radiator 3" specifically further includes the following detailed steps:

[0072] In the defrosting mode: Before the defrosting mode is switched, in the heating mode, adjust the opening degree of the throttling element 4 to throttle the refrigerant flowing to the refrigerant radiator 3, so that the refrigerant temperature at the outlet of the refrigerant radiator 3 is greater than the third preset dew point temperature; then switch to the cooling mode for defrosting.

[0073] The outlet refrigerant temperature is higher than the third preset dew point temperature, that is, the temperature of the refrigerant radiator 3 after heat exchange is higher than the third preset dew point temperature, and 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 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 temperature of the third preset dew point, and thus it can be ensured 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.

[0074] 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 refrigerant temperature at the outlet to be as close as possible to the third preset dew point temperature can keep the temperature of the refrigerant radiator 3 at a relatively low level, which can ensure effective heat dissipation for the drive module. By the above-mentioned outlet refrigerant temperature, while reducing the temperature of the electric control drive module, condensation on the surface of the electric control drive module can be effectively prevented under various operating conditions during the operation of the air conditioner; when the temperature of the drive module is low and the required cooling capacity is small, since the third preset dew point temperature is higher than the dew point temperature, it can ensure that condensation does 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.

[0075] When the air conditioning system switches to the cooling mode for defrosting, adjust the opening degree of the 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 + preset temperature difference. The preset temperature difference is relatively small, specifically, it can be 3°C, etc. In other embodiments, the preset temperature difference can also be 2°C, 4°C, or 5°C, etc. The purpose is to make the temperature of the inlet refrigerant greater than the first preset dew point temperature and relatively close to the fourth preset dew point temperature; it can keep the drive module at a relatively low temperature state all the time, thereby preventing the refrigerant temperature entering the cold radiator from being too high and preventing condensation from occurring due to excessive temperature change of the drive module when the defrosting mode ends and switches back to the heating mode.

[0076] Among them, the fourth preset dew point temperature is determined according to 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.

[0077] By the refrigerant inlet temperature of the above-mentioned temperature, while reducing the temperature of the electric control drive module, condensation on the surface of the electric control drive module can be effectively prevented under various operating conditions during the operation of the air conditioner; when the temperature of the drive module is low and the required cooling capacity is small, since the fourth preset dew point temperature is higher than the dew point temperature, it can ensure that condensation does 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.

[0078] As Figure 3 shown, the control method of this air conditioning system includes the following detailed steps:

[0079] S01. Obtain the working mode of the air conditioning system;

[0080] S02. Determine whether the working mode is the cooling mode; if so, proceed to step S03; if not, proceed to step S04;

[0081] S03. Adjust the opening degree of the control valve 2 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;

[0082] S04. Determine whether the working mode is the heating mode; if so, go to step S05; if not, go to step S06;

[0083] S05. Adjust the opening degree of the throttling element 4 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;

[0084] S06. Determine whether the working mode is the defrosting mode; if so, go to step S07;

[0085] S07. Before the defrosting mode is switched, when in the heating mode, adjust the opening degree of the throttling element 4 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; and adjust the opening degree of the control valve 2 to make the refrigerant temperature at the inlet of the refrigerant radiator 3 greater than the fourth preset dew point temperature and less than the fourth preset dew point temperature + preset temperature difference.

[0086] So far, the technical solution of the present invention has been described in conjunction with the preferred embodiments shown in the accompanying 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 control valve (2), a refrigerant radiator (3), a throttling element (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 air conditioning system further includes a first temperature detector (11) which is arranged on one side of the refrigerant radiator (3) close to the control valve (2) and is used to detect the temperature of the refrigerant flowing into or out of the refrigerant radiator (3).

2. The air conditioning system according to claim 1, wherein, The air conditioning system further includes a compressor (6) and a four-way valve (8), wherein 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); One side of the outdoor heat exchanger (1) far from the control valve (2) is connected to the third interface of the four-way valve (8), and one side of the indoor heat exchanger (5) far from the throttling element (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.

3. The air conditioning system according to claim 1, characterized in that, The air conditioning system further includes a second temperature detector which is arranged at the drive module and is used to detect 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, adjusting the opening degrees of the control valve (2) and / or the throttling element (4) to control the refrigerant temperature at the inlet and outlet of the refrigerant radiator (3).

5. The control method of the air conditioning system according to claim 4, characterized in that, "According to the working mode of the air conditioning system and the dew point temperature of the ambient air, adjusting the opening degrees of the control valve (2) and / or the throttling element (4) to control the refrigerant temperature at the inlet and outlet of the refrigerant radiator (3)" includes: In the cooling mode, adjusting the opening degree of the control valve (2) to make the refrigerant temperature at the inlet of the refrigerant radiator (3) between the ambient temperature and the dew point temperature, where the ambient temperature is higher than the dew point temperature.

6. The control method of the air conditioning system according to claim 4, characterized in that, "According to the working mode of the air conditioning system and the dew point temperature of the ambient air, adjusting the opening degrees of the control valve (2) and / or the throttling element (4) to control the refrigerant temperature at the inlet and outlet of the refrigerant radiator (3)" includes: In the cooling mode, adjusting the opening degree of the control valve (2) 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, where the first preset dew point temperature is lower than the temperature of the drive module.

7. The control method of 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, adjusting the opening degrees of the control valve (2) and / or the throttling element (4) to control the refrigerant temperature at the inlet and outlet of the refrigerant radiator (3)" includes: In the heating mode, adjusting the opening degree of the throttling element (4) to make the refrigerant temperature at the outlet of the refrigerant radiator (3) greater than the second preset dew point temperature; Preferably, the refrigerant temperature at the outlet 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 control method of the air conditioning system according to claim 7, characterized in that, "Adjust the opening degrees of the control valve (2) and / or the throttling element (4) 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 and outlet of the refrigerant radiator (3)" includes: In the defrosting mode, before the defrosting mode is switched, when in the heating mode, adjust the opening degree of the throttling element (4) so that the refrigerant temperature at the outlet of the refrigerant radiator (3) is greater than the third preset dew point temperature; then switch to the cooling mode for defrosting; Preferably, the refrigerant temperature at the outlet of the refrigerant radiator (3) 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.

9. The control method of the air conditioning system according to claim 8, wherein When the air conditioning system switches to the cooling mode for defrosting, adjust the opening degree of the 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 + preset temperature difference.

10. The control method of the air conditioning system according to claim 9, characterized in that, When the air conditioning system is in the maximum load state, 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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