Air conditioning system and control method and control device thereof

Abstract

The invention provides an air conditioning system and a control method and device thereof. The air conditioning system comprises a main refrigerant loop and a main power module, the main refrigerant loop comprises an outdoor heat exchanger, an indoor heat exchanger and a main compressor, and the main power module is used for conducting driving frequency conversion on the main compressor; the secondary refrigerant loop comprises a condenser, a refrigerant radiator and a secondary compressor; wherein the refrigerant radiator is in heat transfer connection with the main power module, the refrigerant radiator comprises a secondary refrigerant heat exchange pipeline and a main refrigerant heat exchange pipeline, the secondary refrigerant heat exchange pipeline is connected to the downstream of the condenser, and the main refrigerant heat exchange pipeline is located between the outdoor heat exchanger and the indoor heat exchanger. The secondary refrigerant loop is introduced to assist heat dissipation, so that the heat dissipation efficiency can be improved, and the reliability and economical efficiency of the system can be enhanced while the user experience is guaranteed.

Description

Technical Field

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

[0002] Currently, most air conditioners, especially large-scale air conditioners, basically use variable-frequency compressors, and variable-frequency compressors require variable-frequency power modules to drive the frequency conversion. The actual power module will generate a relatively high temperature. At present, most of them are in close contact with the refrigerant radiator and the power module, and the refrigerant inside the system itself flows through the refrigerant radiator to reduce the temperature of the power module, prevent the power module from operating at high temperature, thereby improving the service life of the power module and reducing the defective rate of the power module. In addition, if the temperature of the power module is too high, it will cause the compressor to automatically reduce the frequency, seriously affecting the refrigeration and heating effects.

[0003] Currently, the mainstream application is to cool the refrigerant radiator with the medium-temperature and high-pressure refrigerant after condensation in the main refrigerant circuit, so as to solve the problem of high temperature of the power module. However, in this way, when facing a large variable-frequency air conditioning system, when the load is small and the compressor frequency is low, especially when the compressor just starts and the refrigerant charge is large (such as a large multi-connected system), the refrigerant circulation volume and circulation speed are low, and the heat generated by the compressor power module cannot be quickly taken away by the refrigerant after the condenser, resulting in the temperature of the power module rising above the limit value, causing the compressor to frequently stop. In the long run, it affects the user experience and the reliability of the power module, and is prone to damage it. Summary of the Invention

[0004] The present invention provides an air conditioning system, a control method and a control device thereof to solve the defects existing in the prior art and achieve the following technical effects: By introducing a secondary refrigerant circuit to assist in heat dissipation, not only can the heat dissipation efficiency be improved, but also the reliability and economy of the system can be enhanced while ensuring the user experience.

[0005] An air conditioning system according to an embodiment of the first aspect of the present invention includes: A main refrigerant circuit and a main power module. The main refrigerant circuit includes an outdoor heat exchanger, an indoor heat exchanger and a main compressor, and the main power module is used to drive the frequency conversion of the main compressor; A secondary refrigerant circuit, including a condenser, a refrigerant radiator and a secondary compressor; Wherein, the refrigerant radiator is heat transfer connected to the main power module. The refrigerant radiator includes a secondary refrigerant heat exchange pipeline and a main refrigerant heat exchange pipeline. Among them, the secondary refrigerant heat exchange pipeline is connected downstream of the condenser, and the main refrigerant pipeline is located between the outdoor heat exchanger and the indoor heat exchanger.

[0006] According to an embodiment of the present invention, an evaporator is further included in the secondary refrigerant circuit; The evaporator and the refrigerant radiator are integrally formed, and in this case, the refrigerant radiator serves as the evaporator; or, the evaporator and the refrigerant radiator are designed separately. In this case, the refrigerant radiator is connected in series between the condenser and the evaporator, and both ends of the secondary refrigerant heat exchange pipeline are respectively communicated with the condenser and the evaporator.

[0007] According to an embodiment of the present invention, the number of the secondary refrigerant heat exchange pipelines is multiple, and the multiple secondary refrigerant heat exchange pipelines are connected in parallel with each other; the number of the primary refrigerant heat exchange pipelines is also multiple, and the multiple primary refrigerant heat exchange pipelines are connected in parallel with each other; Among them, the multiple secondary refrigerant heat exchange pipelines and the multiple primary refrigerant heat exchange pipelines are arranged in an interleaved manner.

[0008] According to an embodiment of the present invention, the sum of the cross-sectional areas of all the secondary refrigerant heat exchange pipelines is not less than 70% of the cross-sectional area of the outdoor heat exchanger, and the sum of the cross-sectional areas of all the primary refrigerant heat exchange pipelines is not less than 70% of the cross-sectional area of the condenser; Preferably, the secondary refrigerant heat exchange pipeline and / or the primary refrigerant heat exchange pipeline is provided with a serrated corrugation inside.

[0009] According to an embodiment of the present invention, a first solenoid valve is provided at the inlet of the primary refrigerant heat exchange pipeline, a short-circuit pipeline is further provided between the indoor heat exchanger and the outdoor heat exchanger, a second solenoid valve is provided on the short-circuit pipeline, and the short-circuit pipeline is connected in parallel with the primary refrigerant heat exchange pipeline and the first solenoid valve.

[0010] According to an embodiment of the second aspect of the present invention, a control method for the air-conditioning system according to the embodiment of the first aspect of the present invention includes: Obtain the temperature of the main power module; According to the temperature of the main power module, control and adjust the working parameters of the primary refrigerant circuit and / or the secondary refrigerant circuit.

[0011] According to an embodiment of the present invention, the step of controlling and adjusting the working parameters of the primary refrigerant circuit and / or the secondary refrigerant circuit according to the temperature of the main power module specifically includes: Obtain the operating frequency of the main compressor, and control the start or stop of the secondary compressor according to the operating frequency of the main compressor and / or the temperature of the main power module; Wherein, if the operating frequency of the main compressor is less than or equal to the preset lower frequency limit and the temperature of the main power module is greater than or equal to the preset upper temperature limit, the secondary compressor is controlled to start; or, if the operating frequency of the main compressor is greater than or equal to the preset upper frequency limit and the temperature of the main power module is less than or equal to the preset lower temperature limit, the secondary compressor is controlled to stop; or, if the temperature of the main power module is greater than or equal to the maximum allowable temperature, the secondary compressor is controlled to stop.

[0012] According to an embodiment of the present invention, if the evaporator and the refrigerant radiator are integrally formed, the step of controlling and adjusting the operating parameters of the main refrigerant circuit and / or the secondary refrigerant circuit according to the temperature of the main power module specifically further includes: When the secondary compressor is started, determine the target evaporation temperature of the secondary refrigerant circuit according to the range of the temperature of the main power module; According to the target evaporation temperature, control and adjust the operating frequency of the secondary compressor until the actual evaporation temperature of the secondary refrigerant circuit reaches the target evaporation temperature; Or, if the evaporator and the refrigerant radiator are separately designed, the step of controlling and adjusting the operating parameters of the main refrigerant circuit and / or the secondary refrigerant circuit according to the temperature of the main power module specifically further includes: When the secondary compressor is started, determine the target condensation pressure of the secondary refrigerant circuit according to the range of the temperature of the main power module; According to the target condensation pressure, control and adjust the operating frequency of the secondary compressor until the actual condensation pressure of the secondary refrigerant circuit reaches the target condensation pressure.

[0013] According to an embodiment of the present invention, if the evaporator and the refrigerant radiator are separately designed, the control method further includes: Obtain the condenser outlet temperature of the secondary refrigerant circuit; According to the condenser outlet temperature and the temperature of the main power module, control and adjust the operating parameters of the external fan of the secondary refrigerant circuit; Wherein, when the difference between the temperature of the power module of the main refrigerant circuit and the condenser outlet temperature is less than the first set difference, control the external fan of the secondary refrigerant circuit to maintain operation at the set highest gear; Or, when the difference between the temperature of the main power module and the condenser outlet temperature is greater than or equal to the first set difference and less than the second set difference, control the external fan of the secondary refrigerant circuit to increase the gear at the first gear-up speed and not exceed the first set gear at most; Alternatively, when the difference between the temperature of the main power module and the condenser outlet temperature is greater than or equal to a second set difference and less than a third set difference, control the external fan of the secondary refrigerant circuit to maintain the current gear and not exceed the second set gear at most; Alternatively, when the difference between the temperature of the main power module and the condenser outlet temperature is greater than or equal to a third set difference and less than a fourth set difference, control the external fan of the secondary refrigerant circuit to increase the gear at a second gear-up speed and not exceed the third set gear at most; Alternatively, when the difference between the temperature of the main power module and the condenser outlet temperature is greater than or equal to a fourth set difference, control the external fan of the secondary refrigerant circuit to increase the gear at a third gear-up speed and not exceed the fourth set gear at most; Wherein, the first gear-up speed is greater than the second gear-up speed, the second gear-up speed is greater than the third gear-up speed, and the first set gear is greater than the second set gear, the second set gear is greater than the third set gear, and the third set gear is greater than the fourth set gear.

[0014] The control device of the air-conditioning system according to the third aspect embodiment of the present invention based on the first aspect embodiment of the present invention includes: An acquisition module for acquiring the temperature of the main power module; A control module for controlling and adjusting the working parameters of the main refrigerant circuit and / or the secondary refrigerant circuit according to the temperature of the main power module.

[0015] The air-conditioning system of the present invention has at least the following advantages compared with the background art.

[0016] (1) Improve the heat dissipation effect: By introducing a secondary refrigerant circuit, when the compressor of the main refrigerant circuit operates at a low frequency, the refrigerant circulation of the secondary refrigerant circuit can effectively take away the heat of the power module of the main refrigerant circuit, solving the problem of poor heat dissipation effect during low-frequency operation.

[0017] (2) Improve the user experience: The traditional method of reducing the frequency or even stopping the machine to reduce the temperature of the power module will seriously affect the user experience, while the dual-system design of the present invention can avoid this situation, maintain the continuity of the compressor operation, and thus improve the comfort of the user.

[0018] (3) Enhance the economy: Compared with the traditional single large-system solution, the design of embedding the secondary refrigerant circuit into the main refrigerant circuit in the present invention achieves a good heat dissipation effect without adding too much cost, improving the overall economy of the system.

[0019] (4) Reducing system fluctuations: The practice of controlling temperature by increasing the minimum set frequency of the air conditioning system is avoided, which can lead to excessive indoor temperature fluctuations. The solution of the present invention makes the system operate more smoothly.

[0020] (5) Preventing frequent shutdowns: Since the compressor may frequently shut down due to the excessive temperature of the power module, and the present invention can better control the temperature of the power module, thus reducing the unnecessary number of shutdowns.

[0021] (6) Extending the equipment life: By effectively dissipating heat from the power module, the risk of its high-temperature operation is reduced, thereby indirectly increasing the service life of the compressor and related components.

[0022] (7) High flexibility: The system of the present invention can flexibly adjust the operating parameters of the secondary refrigerant circuit, such as the compressor frequency, valve opening, and fan speed, according to the operating state of the main refrigerant circuit and the actual temperature of the power module, ensuring that the temperature of the power module in the main refrigerant circuit is always within a safe and controllable range.

[0023] As can be seen from the above, the air conditioning system of the present invention introduces a secondary refrigerant circuit to assist in heat dissipation, which can not only improve the heat dissipation efficiency, but also enhance the reliability and economy of the system while ensuring the user experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0025] Figure 1 It is a schematic structural diagram of an air conditioning system provided by an embodiment of the present invention.

[0026] Figure 2 It is one of the schematic structural diagrams of the refrigerant radiator provided by the present invention.

[0027] Figure 3 It is another schematic structural diagram of the refrigerant radiator provided by the present invention.

[0028] Figure 4 It is a schematic structural diagram of an air conditioning system provided by another embodiment of the present invention.

[0029] Figure 5 It is a schematic structural diagram of an air conditioning system provided by yet another embodiment of the present invention.

[0030] Figure 6 It is a schematic flow diagram of the control method of the air conditioning system provided by the present invention.

[0031] Figure 7 It is a schematic structural diagram of a control device for an air-conditioning system provided by the present invention.

[0032] Figure 8 It is a schematic structural diagram of an electronic device provided by the present invention. Description of the Drawings: 1. Main refrigerant circuit; 11. Outdoor heat exchanger; 12. Indoor heat exchanger; 13. Main compressor; 14. Four-way valve; 2. Main power module; 3. Secondary refrigerant circuit; 31. Condenser; 32. Refrigerant radiator; 33. Secondary compressor; 34. Evaporator; 35. Throttling device; 41. Secondary refrigerant heat exchange pipeline; 42. Main refrigerant heat exchange pipeline; 51. First solenoid valve; 52. Short-circuit pipeline; 53. Second solenoid valve. Detailed Embodiments

[0034] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions in the present invention will be clearly and completely described below with reference to the accompanying drawings in the present invention. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present invention without making creative efforts shall fall within the protection scope of the present invention.

[0035] In the description of this specification, the descriptions referring to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the embodiments of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without conflict, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0036] As Figures 1 to 5 shown, an air-conditioning system according to an embodiment of the first aspect of the present invention includes a main refrigerant circuit 1, a main power module 2, and a secondary refrigerant circuit 3.

[0037] The main refrigerant circuit 1 includes an outdoor heat exchanger 11, an indoor heat exchanger 12, and a main compressor 13, and the main power module 2 is used to drive and frequency-convert the main compressor 13.

[0038] The secondary refrigerant circuit 3 includes a condenser 31, a refrigerant radiator 32, and a secondary compressor 33.

[0039] Among them, the refrigerant radiator 32 is heat-transfer connected to the main power module 2. The refrigerant radiator 32 includes a secondary refrigerant heat exchange pipeline 41 and a main refrigerant heat exchange pipeline 42. Among them, the secondary refrigerant heat exchange pipeline 41 is connected downstream of the condenser 31, and the main refrigerant pipeline is located between the outdoor heat exchanger 11 and the indoor heat exchanger 12.

[0040] Next, each component in the air-conditioning system of the present invention will be introduced in turn.

[0041] The main refrigerant circuit 1 includes an outdoor heat exchanger 11 (usually a condenser 31), an indoor heat exchanger 12 (usually an evaporator 34), and a main compressor 13. The main compressor 13 is driven by the main power module 2. The main power module 2 is a variable-frequency drive module used to adjust the operating frequency of the compressor to adapt to different load requirements. The main power module 2 generates a large amount of heat. Overheating of the main power module 2 will cause the main compressor 13 to reduce its frequency. Therefore, it is necessary to cool the main power module 2 when its temperature is too high. The refrigerant radiator 32 in the system dissipates heat from the main power module 2. Further, the main refrigerant circuit 1 can be a heat pump system, including a four-way valve 14 for reversing heating. Further, a double throttling device 35 can be set for the outdoor heat exchanger 11 and the indoor heat exchanger 12 in the main refrigerant circuit 1 to ensure that the refrigerant flowing through the refrigerant radiator 32 is a medium-temperature and high-pressure refrigerant liquid.

[0042] The secondary refrigerant circuit 3 includes a condenser 31, a refrigerant radiator 32, and a secondary compressor 33. The refrigerant radiator 32 of the secondary refrigerant circuit 3 exchanges heat with the main power module 2 to reduce the temperature of the main power module 2. The refrigerant radiator 32 includes a secondary refrigerant heat exchange pipeline 41 and a main refrigerant heat exchange pipeline 42. These two heat exchange pipelines are respectively connected downstream of the condenser 31 in the secondary refrigerant circuit 3 and between the outdoor heat exchanger 11 and the indoor heat exchanger 12 in the main refrigerant circuit 1.

[0043] The refrigeration capacity of the secondary refrigerant circuit 3 should be smaller than that of the main refrigerant circuit 1 and does not directly participate in the indoor-side refrigeration and heating effects. The secondary refrigerant circuit 3 and the main refrigerant circuit 1 share a refrigerant radiator 32. After the refrigerant in the secondary refrigerant circuit 3 is condensed, it directly passes through the refrigerant radiator 32. The refrigerant in the secondary refrigerant circuit 3 first passes through the condenser 31, then through the refrigerant radiator 32, and finally returns to the compressor.

[0044] The condenser 31 of the secondary refrigerant circuit 3 can be a plate heat exchanger or a fin heat exchanger. Further, the secondary compressor 33 of the secondary refrigerant circuit 3 can be a scroll compressor, a rotor compressor, or a slider compressor. Further, the condenser 31 end of the secondary refrigerant circuit 3 can be a fin heat exchanger and a fan for forced air convection heat exchange, or a plate heat exchanger or a shell-and-tube heat exchanger in a water system. Freon flows through one end and water flows through the other end, but its ultimate purpose is to condense the refrigerant in the condenser 31.

[0045] In addition, the main refrigerant circuit 1 and the secondary refrigerant circuit 3 can be installed within one assembly unit or in different assembly units. In the dual-system, except for the refrigerant radiator 32 of the main power module 2 and the secondary refrigerant circuit 3, the remaining components do not interfere with each other, and the control is convenient and flexible.

[0046] Based on the above structural introduction of the air-conditioning system, the specific working principle of the air-conditioning system of the present invention is as follows.

[0047] During the operation of the air-conditioning system, the main refrigerant circuit 1 and the secondary refrigerant circuit 3 work together to ensure the efficient operation of the system. When the main compressor 13 operates, a large amount of heat is generated, and this heat is transferred to the main power module 2. To prevent the main power module 2 from overheating, heat dissipation is carried out through the refrigerant radiator 32 in the secondary refrigerant circuit 3. Specifically, in the case of the main compressor 13 operating at high frequency, the heat of the main power module 2 is mainly carried away by the medium-temperature and high-pressure liquid refrigerant condensed in the main refrigerant circuit 1; while in the case of the main compressor 13 operating at low frequency (frequency reduction due to other constraints or compressor frequency reduction caused by reduced load) or just starting, the medium-temperature and high-pressure refrigerant liquid condensed in the secondary refrigerant circuit 3 is used to lower the temperature of the main power module 2.

[0048] In actual use, the general control logic of the above air-conditioning system is as follows: The temperature of the main power module 2 is monitored in real time through sensors. According to the temperature of the main power module 2, the working parameters of the main refrigerant circuit 1 and / or the secondary refrigerant circuit 3 are controlled and adjusted: If the temperature of the main power module 2 is too high, the system will start the secondary refrigerant circuit 3, and by adjusting measures such as the frequency of the secondary compressor 33, the opening degree of the throttling device 35, and the fan speed, etc., to improve the heat dissipation capacity of the secondary refrigerant circuit 3, thereby reducing the temperature of the main power module 2. On the contrary, if the temperature of the main power module 2 is within the safe range, the working intensity of the secondary refrigerant circuit 3 can be reduced to save energy.

[0049] Furthermore, the working process of the air-conditioning system of the present invention is as follows: When the air-conditioning system is started, the main compressor 13 starts to operate, generating high-temperature and high-pressure refrigerant vapor, which becomes medium-temperature and high-pressure refrigerant liquid after being cooled by the outdoor heat exchanger 11.

[0050] At this time, the refrigerant liquid will pass through the refrigerant radiator 32. If the temperature of the main power module 2 is normal, the refrigerant will continue to flow to the indoor heat exchanger 12 to evaporate and return to the compressor, completing a cycle.

[0051] If the main refrigerant circuit 1 reduces frequency due to load or the compressor restarts, the refrigerant circulation volume decreases and the power module temperature rises. At this time, the secondary refrigerant circuit 3 will be turned on. The refrigerant in the secondary refrigerant circuit 3 becomes a low-temperature and low-pressure refrigerant gas-liquid mixture state after passing through the condenser 31, enters the refrigerant radiator 32, and absorbs the heat of the power module, thereby reducing the temperature of the power module.

[0052] The main refrigerant circuit 1 and the secondary refrigerant circuit 3 work together to ensure that even under low-load conditions, the power module can be maintained within a suitable temperature range, preventing the compressor from reducing its frequency or shutting down due to overheating.

[0053] Through such a design, the air-conditioning system can maintain good working efficiency under different load conditions, effectively protect the power module, and extend the service life of the system.

[0054] In summary, the air-conditioning system of the present invention has at least the following advantages compared with the background art.

[0055] (1) Improving the heat dissipation effect: By introducing the secondary refrigerant circuit 3, when the compressor of the main refrigerant circuit 1 operates at a low frequency, the refrigerant circulation of the secondary refrigerant circuit 3 can be used to effectively remove the heat of the power module of the main refrigerant circuit 1, solving the problem of poor heat dissipation effect during low-frequency operation.

[0056] (2) Improving the user experience: The traditional method of reducing the frequency or even shutting down the compressor to lower the temperature of the power module will seriously affect the user experience, while the dual-system design of the present invention can avoid this situation, maintain the continuity of the compressor operation, and thus improve the user's comfort.

[0057] (3) Enhancing the economy: Compared with the traditional single large-system solution, the design of embedding the secondary refrigerant circuit 3 into the main refrigerant circuit 1 of the present invention achieves a good heat dissipation effect without adding too much cost, improving the overall economy of the system.

[0058] (4) Reducing system fluctuations: It avoids the practice of controlling the temperature by increasing the minimum frequency set for the air-conditioning system, which will cause excessive fluctuations in the indoor temperature. The solution of the present invention makes the system operation more stable.

[0059] (5) Preventing frequent shutdowns: Since the excessive temperature of the power module may cause the compressor to shut down frequently, and the present invention can better control the temperature of the power module, thus reducing the unnecessary number of shutdowns.

[0060] (6) Extending the equipment life: By effectively dissipating the heat of the power module, the risk of its high-temperature operation is reduced, thereby indirectly increasing the service life of the compressor and related components.

[0061] (7) High flexibility: The system of the present invention can flexibly adjust the operating parameters of the secondary refrigerant circuit 3, such as the compressor frequency, valve opening, and fan speed, according to the operating state of the main refrigerant circuit 1 and the actual temperature of the power module, ensuring that the temperature of the power module of the main refrigerant circuit 1 is always within a safe and controllable range.

[0062] As can be seen from the above, the air conditioning system of the present invention can assist heat dissipation by introducing the secondary refrigerant circuit 3, which can not only improve the heat dissipation efficiency, but also enhance the reliability and economy of the system while ensuring user experience.

[0063] like Figure 4 and Figure 5 As shown, according to some embodiments of the present invention, the secondary refrigerant circuit 3 further includes an evaporator 34. The evaporator 34 and the refrigerant radiator 32 are integrally formed, and the refrigerant radiator 32 serves as the evaporator 34.

[0064] In this embodiment, the refrigerant radiator 32 and the evaporator 34 are integrated together. This means that the refrigerant radiator 32 itself plays the role of the evaporator 34, that is, the refrigerant in the secondary refrigerant circuit 3 evaporates in the refrigerant radiator 32, and this process also takes away the heat of the power module of the main refrigerant circuit 1, thereby achieving the purpose of heat dissipation. The advantage of this design is that it simplifies the complexity of the system, reduces the number of components, helps to reduce costs, and may improve the compactness of the system.

[0065] like Figure 1 As shown, according to some other embodiments of the present invention, the secondary refrigerant circuit 3 further includes an evaporator 34. The evaporator 34 and the refrigerant radiator 32 are designed in a split type. At this time, the refrigerant radiator 32 is connected in series between the condenser 31 and the evaporator 34, and both ends of the secondary refrigerant heat exchange pipeline 41 are connected to the condenser 31 and the evaporator 34 respectively.

[0066] In this embodiment, another form is to design the refrigerant radiator 32 and the evaporator 34 separately. In this configuration, the refrigerant radiator 32 is arranged between the condenser 31 and the evaporator 34 to form a series structure. The two ends of the secondary refrigerant heat exchange pipeline 41 are respectively connected to the condenser 31 and the evaporator 34. This design allows the refrigerant radiator 32 to operate as an independent heat exchanger, and its main task is still to absorb the heat of the power module of the main refrigerant circuit 1. However, compared with the one-piece design, the split design provides more flexibility, such as the design of the refrigerant radiator 32 and the evaporator 34 can be independently optimized to meet specific application requirements.

[0067] It should be pointed out that each of the above designs has its own advantages, and which one to choose depends on the specific needs of the actual application. For example, if a compact and cost-effective solution is required, the one-piece design may be a better choice. If higher heat exchange efficiency is required or there are special requirements on the space layout, the split design may be more suitable. Regardless of the design, they are all aimed at improving the performance of the air-conditioning system through effective thermal management, especially keeping the temperature of the power module within a reasonable range during low-frequency operation.

[0068] like Figure 2and Figure 3 As shown, according to some embodiments of the present invention, the number of secondary refrigerant heat exchange pipelines 41 is multiple, and the multiple secondary refrigerant heat exchange pipelines 41 are connected in parallel with each other; the number of primary refrigerant heat exchange pipelines 42 is also multiple, and the multiple primary refrigerant heat exchange pipelines 42 are connected in parallel with each other.

[0069] Among them, the multiple secondary refrigerant heat exchange pipelines 41 and the multiple primary refrigerant heat exchange pipelines 42 are arranged in an interleaved manner.

[0070] In the air-conditioning system of the present invention, both the secondary refrigerant heat exchange pipelines 41 and the primary refrigerant heat exchange pipelines 42 are designed to be multiple, and these pipelines are connected in parallel with each other. This design allows the refrigerant to flow simultaneously in multiple paths, increasing the heat dissipation area of the system, thereby improving the heat dissipation efficiency. More importantly, an interleaved arrangement is adopted between the multiple secondary refrigerant heat exchange pipelines 41 and the multiple primary refrigerant heat exchange pipelines 42, which makes the heat exchange more uniform and efficient.

[0071] The interleaved arrangement means that the secondary refrigerant heat exchange pipelines 41 and the primary refrigerant heat exchange pipelines 42 are alternately arranged inside the refrigerant radiator 32, which can ensure a good heat exchange interface between the primary refrigerant (medium-temperature and high-pressure) and the secondary refrigerant (low-temperature and low-pressure), and is conducive to the transfer of heat from the primary refrigerant circuit 1 to the secondary refrigerant circuit 3. This structural design also helps to reduce the thermal resistance and improve the overall heat exchange performance of the system.

[0072] In this way, when the refrigerant in the secondary refrigerant circuit 3 becomes a low-temperature and low-pressure liquid or gas-liquid mixture after flowing through the condenser 31, it will exchange heat with the medium-temperature and high-pressure refrigerant in the primary refrigerant circuit 1 inside the refrigerant radiator 32, thereby effectively reducing the temperature of the power module in the primary refrigerant circuit 1. At the same time, due to the parallel design of multiple pipelines, even if a certain pipeline has a problem, it will not completely interrupt the heat dissipation function of the system, increasing the reliability of the system.

[0073] According to some embodiments of the present invention, the secondary refrigerant heat exchange pipelines 41 and the primary refrigerant heat exchange pipelines 42 are separated from each other through an internal partition, and the thickness of the partition is greater than 0.05 mm and less than 1 mm, with the aim of reducing the heat transfer thermal resistance.

[0074] In addition, the partition thickness between the refrigerant radiator 32 and the main power module 2 is greater than 0.05 mm and less than 1 mm, with the aim of reducing the heat transfer thermal resistance. The number of both the secondary refrigerant heat exchange pipelines 41 and the primary refrigerant heat exchange pipelines 42 should be ≥ 2. The inlets and outlets of the primary refrigerant heat exchange pipelines 42 are aggregated and then connected to the outdoor heat exchanger 11 and the indoor heat exchanger 12 in the primary refrigerant circuit 1, and the inlets and outlets of the secondary refrigerant heat exchange pipelines 41 are aggregated and then connected to the condenser 31 and the evaporator 34 in the secondary refrigerant circuit 3.

[0075] Such as Figure 2 and Figure 3As shown, according to some embodiments of the present invention, the sum of the cross-sectional areas of all the secondary refrigerant heat exchange pipelines 41 is not less than 70% of the cross-sectional area of the outdoor heat exchanger 11, and the sum of the cross-sectional areas of all the primary refrigerant heat exchange pipelines 42 is not less than 70% of the cross-sectional area of the condenser 31. Such a design ensures sufficient heat exchange area, enabling the refrigerant in the secondary refrigerant circuit 3 to effectively absorb the heat of the power module in the primary refrigerant circuit 1, thereby ensuring that the power module does not overheat and enhancing the stability and reliability of the system.

[0076] Preferably, the secondary refrigerant heat exchange pipeline 41 and / or the primary refrigerant heat exchange pipeline 42 are provided with serrated corrugations inside.

[0077] The presence of such corrugations increases the internal contact area of the pipeline and promotes the turbulent flow phenomenon of the fluid, thereby enhancing the heat exchange effect. That is, by increasing the friction between the fluid and the pipe wall, heat is more easily transferred from the pipe wall to the flowing refrigerant, improving the heat exchange efficiency.

[0078] In summary, by ensuring that the heat exchange pipeline has sufficient cross-sectional area and the design of internal serrated corrugations, the present invention aims to improve the heat dissipation performance of the air conditioning system under different working conditions. Especially when the compressor operates at low frequency or just starts, it can effectively reduce the temperature of the power module in the primary refrigerant circuit 1 and prevent system instability or shutdown caused by overheating. Such a design not only improves the economy of the system but also ensures the long-term stable operation of the system.

[0079] As Figure 5 shown, according to some embodiments of the present invention, a first solenoid valve 51 is provided at the inlet of the primary refrigerant heat exchange pipeline 42, and a short-circuit pipeline 52 is also provided between the indoor heat exchanger 12 and the outdoor heat exchanger 11. A second solenoid valve 53 is provided on the short-circuit pipeline 52, and the short-circuit pipeline 52 is connected in parallel with the primary refrigerant heat exchange pipeline 42 and the first solenoid valve 51.

[0080] It can be understood that the main purpose of this design is to improve the flexibility and efficiency of the air conditioning system. When the air conditioning system needs to quickly respond to environmental changes or specific operation requirements, by controlling the states of the first solenoid valve 51 and the second solenoid valve 53, the flow direction of the refrigerant can be adjusted, thereby changing the operating mode of the system.

[0081] For example, when heat exchange through the primary refrigerant heat exchange pipeline 42 is not required, the first solenoid valve 51 can be closed and the second solenoid valve 53 can be opened, so that the refrigerant directly flows back from the outdoor heat exchanger 11 to the indoor heat exchanger 12 through the short-circuit pipeline 52, avoiding unnecessary energy loss. On the contrary, when heat exchange through the primary refrigerant heat exchange pipeline 42 is required, the second solenoid valve 53 can be closed and the first solenoid valve 51 can be opened to enable the refrigerant to undergo heat exchange through the primary refrigerant heat exchange pipeline 42.

[0082] This design enables the system to adjust the refrigerant flow path according to actual needs, optimize energy utilization, and improve the energy efficiency ratio of the system. In addition, such a design also provides the system with more operating modes, enabling the system to maintain the best working state under different working conditions.

[0083] The control method, control device, and air conditioning system of the present invention will be described below with reference to the accompanying drawings. Among them, before the detailed description of the embodiments of the present invention, the entire application scenario will be described first. The control method, control device, electronic device, and computer-readable storage medium of the air conditioning system according to the embodiments of the present invention can be applied not only to the local area of the air conditioning system but also to the cloud platform in the Internet field, or the cloud platform in other types of Internet fields, or can also be applied to third-party devices. Among them, the third-party devices may include various different types such as mobile phones, tablets, laptops, in-vehicle computers, and other intelligent terminals.

[0084] Hereinafter, only the control method applicable to the air conditioning system will be taken as an example for illustration. It should be understood that the control method of the embodiments of the present invention can also be applicable to the cloud platform and third-party devices.

[0085] As Figure 6 shown, the control method of the air conditioning system according to the second aspect embodiment of the present invention includes: Step S1, obtaining the temperature of the main power module 2; Step S2, controlling and adjusting the working parameters of the main refrigerant circuit 1 and / or the secondary refrigerant circuit 3 according to the temperature of the main power module 2.

[0086] The specific working process of the control method of the air conditioning system according to the embodiments of the present invention is as follows: The temperature of the main power module 2 is monitored in real time through a sensor or other temperature measuring devices. The temperature of the main power module 2 is an important basis for determining whether to start the secondary refrigerant circuit 3 subsequently and how to adjust the system parameters.

[0087] Based on the temperature of the main power module 2, the system will take corresponding control measures, including but not limited to the following situations: (1) Starting condition of the secondary compressor 33: When the frequency of the main compressor 13 is less than or equal to 20 rps and the temperature of the main power module 2 is greater than or equal to 60 °C, the secondary compressor 33 will start. (2) Control of the frequency of the secondary compressor 33: According to the different temperatures of the main power module 2, the secondary compressor 33 will have different frequency settings. (3) Shut-down condition of the secondary compressor 33: When the frequency of the main compressor 13 is greater than or equal to 45 rps or the temperature of the main power module 2 drops below 43 °C, the secondary compressor 33 will shut down; or when the temperature of the main power module 2 reaches 98 °C and lasts for 2 seconds, as the final protection mechanism, the main compressor 13 will also stop working. (4) Control of the external fan speed: In order to ensure a certain heat transfer temperature between the outlet temperature of the condenser 31 and the main power module 2, the external fan speed of the secondary refrigerant circuit 3 will be controlled. (5) Control of the subcooling degree and the inlet temperature of the refrigerant radiator 32: The throttling device 35 of the secondary refrigerant circuit 3 will be adjusted according to the superheat degree of the evaporator 34 or the temperature difference between the inlet and outlet to ensure that the inlet temperature of the refrigerant radiator 32 is appropriate and the heat exchange effect is guaranteed.

[0088] Through these control measures, it is ensured that under different working conditions, the main refrigerant circuit 1 and the secondary refrigerant circuit 3 can work together to effectively control the temperature of the main power module 2, thereby improving the stability and energy efficiency of the air-conditioning system.

[0089] According to some embodiments of the present invention, the steps of controlling and adjusting the working parameters of the main refrigerant circuit 1 and / or the secondary refrigerant circuit 3 according to the temperature of the main power module 2 specifically include: Obtain the working frequency of the main compressor 13, and control the start or stop of the secondary compressor 33 according to the working frequency of the main compressor 13 and / or the temperature of the main power module 2.

[0090] Among them, if the working frequency of the main compressor 13 is less than or equal to the preset frequency lower limit and the temperature of the main power module 2 is greater than or equal to the preset temperature upper limit, then control the secondary compressor 33 to start; or, if the working frequency of the main compressor 13 is greater than or equal to the preset frequency upper limit and the temperature of the main power module 2 is less than or equal to the preset temperature lower limit, then control the secondary compressor 33 to stop; or, if the temperature of the main power module 2 is greater than or equal to the maximum allowable temperature, then control the secondary compressor 33 to stop.

[0091] For example, when the main compressor 13 has been started, the starting condition of the secondary compressor 33 is: the frequency of the main compressor 13 ≤ 20 rps and the temperature of the main power module 2 Tf ≥ 70 °C; the shutdown condition of the secondary compressor 33 is: the frequency of the main compressor 13 ≥ 45 rps or the temperature of the main power module 2 Tf ≤ 43 °C; or the temperature of the main power module 2 Tf ≥ 98 °C and lasts for 2 s (a final protection mechanism).

[0092] When the main compressor 13 is not in the operating condition, the starting condition of the secondary compressor 33: the main refrigerant circuit 1 receives a start command.

[0093] The secondary compressor 33 starts in advance and runs to the normal mode. The frequency of the secondary compressor 33 reaches 20% of the set maximum operating frequency before the main compressor 13 starts; after the main compressor 13 starts, it controls the compressor frequency of the secondary refrigerant circuit 3.

[0094] The shutdown condition of the secondary compressor 33 is: the frequency of the main compressor 13 ≥ 50 rps or the temperature Tf of the main power module 2 ≤ 43°C; or the temperature Tf of the main power module 2 ≥ 98°C and is maintained for 2 s (a final protection mechanism).

[0095] According to some embodiments of the present invention, if the evaporator 34 and the refrigerant radiator 32 are integrally formed, the steps of controlling and adjusting the operating parameters of the main refrigerant circuit 1 and / or the secondary refrigerant circuit 3 according to the temperature of the main power module 2 specifically further include: When the secondary compressor 33 is started, determine the target evaporation temperature of the secondary refrigerant circuit 3 according to the range of the temperature of the main power module 2; According to the target evaporation temperature, control and adjust the operating frequency of the secondary compressor 33 until the actual evaporation temperature of the secondary refrigerant circuit 3 reaches the target evaporation temperature.

[0096] In this embodiment, the temperature of the main power module 2 is related to the refrigerant circulation amount and temperature difference in the secondary refrigerant circuit 3. The higher the refrigerant circulation amount in the secondary refrigerant circuit 3, the lower the temperature of the main power module 2; the lower the evaporation temperature of the secondary refrigerant circuit 3, that is, the greater the temperature difference between the refrigerant in the evaporator 34 of the secondary refrigerant circuit 3 and the main power module 2, the lower the temperature of the main power module 2.

[0097] It can be understood that the secondary refrigerant circuit 3 makes start-stop actions according to parameters such as the frequency of the main compressor 13, start-stop command, and temperature of the main power module 2 of the main refrigerant circuit 1, and changes and adjusts according to the evaporation temperature Ts of the evaporator 34 of the secondary refrigerant circuit 3 (Ts is the saturation temperature corresponding to the evaporation pressure of the evaporator 34. The low-pressure pressure can be detected by a low-pressure pressure sensor in the secondary refrigerant circuit 3, and then converted into the saturation temperature corresponding to the low-pressure pressure, or a temperature sensor can be installed in the middle section of the refrigerant radiator 32 to detect the evaporation temperature Ts).

[0098] Specifically, the frequency f of the secondary compressor 33 is determined according to the target evaporation temperature Ts of the refrigerant radiator 32. If the target evaporation temperature cannot be reached, the frequency of the secondary compressor 33 will keep increasing; when the target evaporation temperature is reached, the frequency of the secondary compressor 33 tends to be stable; when the target evaporation temperature is exceeded, the frequency of the secondary compressor 33 decreases. That is, the target evaporation temperature is set in advance. The higher the temperature of the main power module 2, the lower the target evaporation temperature. The secondary compressor 33 needs to increase the compressor frequency more to reach the target evaporation temperature. When the compressor frequency increases, the overall refrigerant circulation volume increases, and the heat exchange temperature between the refrigerant radiator 32 and the main power module 2 increases, so the refrigeration effect is better, that is, more heat is taken away from the main power module 2, and the temperature of the main power module 2 decreases.

[0099] Among them, the target evaporation temperature is set in advance according to the experimental results, and the target evaporation temperature is related to the temperature of the main power module 2. The evaporation temperature is detected by a low-pressure pressure sensor or a temperature sensor installed in the middle section of the refrigerant radiator 32.

[0100] For example, when the temperature Tf of the main power module 2 ≥ 50 °C, the secondary compressor 33 starts and runs. The target Ts is 4 °C. Implement PID control. Under this condition, after the secondary compressor 33 starts, the highest operating frequency is 50% of the set maximum compressor frequency, aiming to prevent the frequency of the secondary compressor 33 from fluctuating frequently. For every 1 °C increase in Tf, the frequency of the secondary compressor 33 increases by 2 Hz.

[0101] When the temperature of the main power module 2 satisfies 75 °C > Tf ≥ 60 °C, it generally does not cause condensation, so the influence of the ambient temperature is not included in the conditions, and the target Ts is 3 °C. For every 1 °C increase, the frequency of the secondary compressor 33 increases by 2 Hz. Under this condition, the highest operating frequency of the secondary compressor 33 is 70% of the set maximum compressor frequency.

[0102] When the temperature of the main power module 2 90 °C > Tf ≥ 75 °C, the target Ts is 2 °C. For every 1 °C increase, the frequency of the secondary compressor 33 increases by 3 Hz. To prevent the secondary refrigerant circuit 3 and the main refrigerant circuit 1 from fluctuating back and forth, under this condition, the highest operating frequency of the secondary compressor 33 is 85% of the set maximum compressor frequency.

[0103] When the temperature of the main power module 2 Tf ≥ 90 °C, the target Ts is 1 °C. The secondary compressor 33 operates at the set maximum compressor frequency.

[0104] Implement PID control under the above conditions. After the temperature of the main power module 2 stops rising and stabilizes, the frequency of the secondary compressor 33 is reduced at a speed of 1 rps for 10 seconds to prevent the secondary refrigerant circuit 3 from fluctuating frequently.

[0105] In addition, there is also a certain tolerance control in the above control logic, that is, when the temperature of the main power module 2 drops to 43°C < Tf < 45°C, the secondary compressor 33 reduces to 10% of the set maximum compressor frequency. When the temperature of the main power module 2 drops to Tf < 43°C and lasts for 3 minutes, the secondary compressor 33 stops operating.

[0106] According to some other embodiments of the present invention, if the evaporator 34 and the refrigerant radiator 32 are designed separately, the steps of controlling and adjusting the operating parameters of the main refrigerant circuit 1 and / or the secondary refrigerant circuit 3 according to the temperature of the main power module 2 specifically further include: When the secondary compressor 33 is turned on, determine the target condensing pressure of the secondary refrigerant circuit 3 according to the range of the temperature of the main power module 2. According to the target condensing pressure, control and adjust the operating frequency of the secondary compressor 33 until the actual condensing pressure of the secondary refrigerant circuit 3 reaches the target condensing pressure.

[0107] In this embodiment, the temperature of the main power module 2 is related to the refrigerant circulation volume and temperature difference of the secondary refrigerant circuit 3. The higher the refrigerant circulation volume of the secondary refrigerant circuit 3, the lower the temperature of the main power module 2; the lower the outlet temperature of the condenser 31, that is, the lower the subcooling degree of the condenser 31, and the lower the inlet temperature of the refrigerant radiator 32, the lower the temperature of the main power module 2.

[0108] The secondary refrigerant circuit 3 makes start-stop actions according to the frequency of the main compressor 13, the start-stop instruction and the temperature of the main power module 2, and makes variable adjustment according to the condensing pressure Pd of the secondary refrigerant circuit 3.

[0109] The frequency f of the secondary compressor 33 acts according to the condensing pressure Pd. If the target condensing pressure cannot be reached, the secondary compressor 33 keeps increasing its frequency; if the target condensing pressure is reached, the frequency of the secondary compressor 33 tends to be stable; if the target condensing pressure is exceeded, the secondary compressor 33 reduces its frequency. That is, the target condensing pressure is set in advance. The higher the temperature of the main power module 2, the lower the target condensing pressure, and the higher the compressor frequency the secondary compressor 33 needs to increase to reach the target condensing pressure. When the compressor frequency increases, the overall refrigerant circulation volume increases, and the heat exchange temperature between the refrigerant radiator 32 and the main power module 2 increases, so the refrigeration effect is better, that is, more heat is taken away from the main power module 2, and the temperature of the main power module 2 is reduced. The target condensing pressure is set in advance according to the experimental results and is related to the temperature of the main power module 2.

[0110] For example, if the temperature Tf of the main power module 2 ≥ Tao ambient temperature + 10°C (the purpose is to minimize the problem of condensation in high temperature and high humidity. Under high ambient temperature conditions, the temperature of the power module should be higher than the ambient temperature by a certain value to prevent the generation of condensed water in high temperature and high humidity), and Tf ≥ 50°C, then the secondary compressor 33 is turned on and runs, and the target Pd is 49°C. Implement PID control. Under this condition, after the secondary compressor 33 starts, the maximum operating frequency is 50% of the set maximum frequency of the compressor, aiming to prevent the frequency of the secondary compressor 33 from fluctuating frequently. For every 1°C increase in Tf, the frequency of the secondary compressor 33 increases by 2 Hz.

[0111] If the temperature of the main power module 2 satisfies 75°C > Tf ≥ 60°C (such a high temperature of the power module generally does not cause condensation, so the influence of the ambient temperature is no longer included in the conditions), the target Pd is 51°C. For every 1°C increase, the frequency of the secondary compressor 33 increases by 2 Hz. Under this condition, the maximum operating frequency of the secondary compressor 33 is 70% of the set maximum frequency of the compressor.

[0112] If the temperature of the main power module 2 is 90°C > Tf ≥ 75°C, the target Pd is 53°C. For every 1°C increase, the frequency of the secondary compressor 33 increases by 3 Hz. To prevent the secondary refrigerant circuit 3 and the main refrigerant circuit 1 from fluctuating back and forth, under this condition, the maximum operating frequency of the secondary compressor 33 is 85% of the set maximum frequency of the compressor.

[0113] If the temperature Tf of the main power module 2 ≥ 90°C, the target Pd is 55°C, and at this time the secondary compressor 33 operates at the set maximum frequency of the compressor.

[0114] Under the above conditions, PID control is implemented. After the temperature of the main power module 2 stops rising and stabilizes, the frequency of the secondary compressor 33 is reduced at a speed of 1 rps after 10 seconds of stabilization to prevent the secondary refrigerant circuit 3 from fluctuating frequently.

[0115] In addition, there is a certain tolerance control in the above control logic. Specifically, when the temperature of the main power module 2 drops to 43°C < Tf < 45°C, the secondary compressor 33 reduces to the lowest frequency operation (the secondary refrigerant circuit 3 is relatively small, and its power module can be air-cooled or other forms of cooling). If the temperature of the main power module 2 drops to Tf < 43°C and Tf ≤ Tao ambient temperature + 5°C, and lasts for 3 minutes, the secondary compressor 33 stops.

[0116] According to some embodiments of the present invention, if the evaporator 34 and the refrigerant radiator 32 are designed separately, the control method further includes: Obtain the outlet temperature of the condenser 31 of the secondary refrigerant circuit 3; Control and adjust the operating parameters of the external fan of the secondary refrigerant circuit 3 according to the outlet temperature of the condenser 31 and the temperature of the main power module 2.

[0117] Wherein, when the difference between the temperature of the power module in the main refrigerant circuit 1 and the outlet temperature of the condenser 31 is less than the first set difference, the external fan of the secondary refrigerant circuit 3 is controlled to operate at the set maximum gear; Or, when the difference between the temperature of the main power module 2 and the outlet temperature of the condenser 31 is greater than or equal to the first set difference and less than the second set difference, the external fan of the secondary refrigerant circuit 3 is controlled to increase the gear at the first gear-up speed and not exceed the first set gear at most; Or, when the difference between the temperature of the main power module 2 and the outlet temperature of the condenser 31 is greater than or equal to the second set difference and less than the third set difference, the external fan of the secondary refrigerant circuit 3 is controlled to maintain the current gear and not exceed the second set gear at most; Or, when the difference between the temperature of the main power module 2 and the outlet temperature of the condenser 31 is greater than or equal to the third set difference and less than the fourth set difference, the external fan of the secondary refrigerant circuit 3 is controlled to increase the gear at the second gear-up speed and not exceed the third set gear at most; Or, when the difference between the temperature of the main power module 2 and the outlet temperature of the condenser 31 is greater than or equal to the fourth set difference, the external fan of the secondary refrigerant circuit 3 is controlled to increase the gear at the third gear-up speed and not exceed the fourth set gear at most.

[0118] Wherein, the first gear-up speed is greater than the second gear-up speed, the second gear-up speed is greater than the third gear-up speed, and the first set gear is greater than the second set gear, the second set gear is greater than the third set gear, and the third set gear is greater than the fourth set gear.

[0119] It can be understood that to ensure a certain heat transfer temperature between the outlet temperature of the condenser 31, that is, the refrigerant heat dissipation inlet temperature of the secondary refrigerant circuit 3, and the main power module 2, the outlet temperature of the condenser 31 (i.e., the inlet temperature of the refrigerant radiator 32) Tdef (the position is on the main pipeline at the inlet of the refrigerant radiator 32) is controlled. The outlet temperature Tdef of the condenser 31 is compared with the temperature Tf of the main power module 2 and the external fan speed gear is controlled.

[0120] For example, when Tf < Tdef + 10°C, the external fan speed maintains the set maximum gear operation; the purpose is to maximize the subcooling degree at the outlet of the condenser 31.

[0121] When Tdef + 10°C ≤ Tf < Tdef + 15°C, the external fan increases the gear at a speed of 1 gear per 10 seconds and operates at 75% of the maximum wind speed gear set at the highest gear.

[0122] When Tdef + 15°C ≤ Tf < Tdef + 20°C, the external fan maintains the current gear and operates at 50% of the maximum wind speed gear set at the highest gear.

[0123] When Tdef + 20°C ≤ Tf < Tdef + 25°C, the external fan increases its gear at a rate of one gear every 20 seconds and operates at 25% of the highest gear set for the maximum wind speed gear.

[0124] When Tdef + 25°C ≤ Tf, the external fan increases its gear at a rate of one gear every 25 seconds and operates at 10% of the highest gear set for the maximum wind speed gear.

[0125] The above steps implement PID control. After the temperature of Tdef no longer rises and stabilizes, the rotational speed gear of the external fan of the secondary refrigerant circuit 3 is decreased at a rate of 1 rps every 10 seconds after stabilization, to prevent frequent fluctuations in the secondary refrigerant circuit 3.

[0126] As Figure 7 shown, the control device of the air-conditioning system according to the embodiment of the third aspect of the present invention includes: An acquisition module 110, configured to acquire the temperature of the main power module 2; A control module 120, configured to control and adjust the operating parameters of the main refrigerant circuit 1 and / or the secondary refrigerant circuit 3 according to the temperature of the main power module 2.

[0127] Figure 8 Illustrates a schematic physical structure diagram of an electronic device. As Figure 8 shown, the electronic device may include: a processor 810, a communication interface 820, a memory 830, and a communication bus 840. Among them, the processor 810, the communication interface 820, and the memory 830 complete communication with each other through the communication bus 840. The processor 810 may call the logical instructions in the memory 830 to execute the control method of the air-conditioning system, including: acquiring the temperature of the main power module 2; controlling and adjusting the operating parameters of the main refrigerant circuit 1 and / or the secondary refrigerant circuit 3 according to the temperature of the main power module 2.

[0128] In addition, when the logical instructions in the above-mentioned memory 830 are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or a part of this technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods of the various embodiments of the present invention. The aforementioned storage medium includes: various media such as USB flash drives, mobile hard disks, read-only memories (ROM, Read-Only Memory), random access memories (RAM, Random Access Memory), magnetic disks, or optical discs that can store program codes.

[0129] On the other hand, the present invention also provides a computer program product. The computer program product includes a computer program. The computer program can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute the control method of the air-conditioning system provided by the above-mentioned various methods, including: obtaining the temperature of the main power module 2; and controlling and adjusting the working parameters of the main refrigerant circuit 1 and / or the secondary refrigerant circuit 3 according to the temperature of the main power module 2.

[0130] In yet another aspect, the present invention also provides a non-transitory computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, it is implemented to execute the control method of the air-conditioning system provided by the above-mentioned various methods, including: obtaining the temperature of the main power module 2; and controlling and adjusting the working parameters of the main refrigerant circuit 1 and / or the secondary refrigerant circuit 3 according to the temperature of the main power module 2.

[0131] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed to multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment. A person of ordinary skill in the art can understand and implement it without creative labor.

[0132] Through the description of the above embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus a necessary general hardware platform, and of course, it can also be implemented by hardware. Based on such an understanding, the essence of the above technical solution, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods of each embodiment or some parts of the embodiments.

[0133] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An air conditioning system, characterized in that, Comprising: A main refrigerant circuit and a main power module, wherein the main refrigerant circuit includes an outdoor heat exchanger, an indoor heat exchanger and a main compressor, and the main power module is used to drive and frequency-convert the main compressor; A secondary refrigerant circuit, including a condenser, a refrigerant radiator and a secondary compressor; Wherein, the refrigerant radiator is heat-transfer connected to the main power module, and the refrigerant radiator includes a secondary refrigerant heat exchange pipeline and a main refrigerant heat exchange pipeline. Among them, the secondary refrigerant heat exchange pipeline is connected downstream of the condenser, and the main refrigerant pipeline is located between the outdoor heat exchanger and the indoor heat exchanger.

2. The air conditioning system according to claim 1, wherein, An evaporator is further included in the secondary refrigerant circuit; The evaporator is integrally formed with the refrigerant radiator, and at this time the refrigerant radiator serves as the evaporator; or, the evaporator and the refrigerant radiator are designed separately. At this time, the refrigerant radiator is connected in series between the condenser and the evaporator, and both ends of the secondary refrigerant heat exchange pipeline are respectively communicated with the condenser and the evaporator.

3. The air-conditioning system according to claim 2, wherein The number of the secondary refrigerant heat exchange pipelines is multiple, and the multiple secondary refrigerant heat exchange pipelines are connected in parallel with each other; the number of the main refrigerant heat exchange pipelines is also multiple, and the multiple main refrigerant heat exchange pipelines are connected in parallel with each other; Among them, the multiple secondary refrigerant heat exchange pipelines and the multiple main refrigerant heat exchange pipelines are arranged alternately with each other.

4. The air conditioning system according to any one of claims 1 to 3, characterized in that, The sum of the cross-sectional areas of all the secondary refrigerant heat exchange pipelines is not less than 70% of the cross-sectional area of the outdoor heat exchanger, and the sum of the cross-sectional areas of all the main refrigerant heat exchange pipelines is not less than 70% of the cross-sectional area of the condenser; Preferably, a serrated corrugation is provided in the secondary refrigerant heat exchange pipeline and / or the main refrigerant heat exchange pipeline.

5. The air-conditioning system according to any one of claims 1 to 3, characterized in that, A first solenoid valve is provided at the inlet of the main refrigerant heat exchange pipeline, and a short-circuit pipeline is further provided between the indoor heat exchanger and the outdoor heat exchanger. A second solenoid valve is provided on the short-circuit pipeline, and the short-circuit pipeline is connected in parallel with the main refrigerant heat exchange pipeline and the first solenoid valve.

6. A control method for an air conditioning system according to any one of claims 1 to 5, characterized in that, Comprising: Obtaining the temperature of the main power module; Controlling and adjusting the working parameters of the main refrigerant circuit and / or the secondary refrigerant circuit according to the temperature of the main power module.

7. The control method of the air conditioning system according to claim 6, wherein The step of controlling and adjusting the working parameters of the main refrigerant circuit and / or the secondary refrigerant circuit according to the temperature of the main power module specifically includes: Obtaining the operating frequency of the main compressor, and controlling the start or stop of the secondary compressor according to the operating frequency of the main compressor and / or the temperature of the main power module; Among them, if the operating frequency of the main compressor is less than or equal to the preset frequency lower limit and the temperature of the main power module is greater than or equal to the preset temperature upper limit, then control the secondary compressor to start; or, if the operating frequency of the main compressor is greater than or equal to the preset frequency upper limit and the temperature of the main power module is less than or equal to the preset temperature lower limit, then control the secondary compressor to stop; or, if the temperature of the main power module is greater than or equal to the maximum allowable temperature, then control the secondary compressor to stop.

8. The control method of the air conditioning system according to claim 7, wherein, If the evaporator and the refrigerant radiator are integrally formed, the step of controlling and adjusting the operating parameters of the main refrigerant circuit and / or the secondary refrigerant circuit according to the temperature of the main power module further specifically includes: When the secondary compressor is turned on, determine the target evaporation temperature of the secondary refrigerant circuit according to the range of the temperature of the main power module; According to the target evaporation temperature, control and adjust the operating frequency of the secondary compressor until the actual evaporation temperature of the secondary refrigerant circuit reaches the target evaporation temperature; Alternatively, if the evaporator and the refrigerant radiator are separately designed, the step of controlling and adjusting the operating parameters of the main refrigerant circuit and / or the secondary refrigerant circuit according to the temperature of the main power module further specifically includes: When the secondary compressor is turned on, determine the target condensation pressure of the secondary refrigerant circuit according to the range of the temperature of the main power module; According to the target condensation pressure, control and adjust the operating frequency of the secondary compressor until the actual condensation pressure of the secondary refrigerant circuit reaches the target condensation pressure.

9. The control method of the air conditioning system according to claim 7, characterized in that, If the evaporator and the refrigerant radiator are separately designed, the control method further includes: Obtain the condenser outlet temperature of the secondary refrigerant circuit; According to the condenser outlet temperature and the temperature of the main power module, control and adjust the operating parameters of the external fan of the secondary refrigerant circuit; Wherein, when the difference between the temperature of the power module of the main refrigerant circuit and the condenser outlet temperature is less than the first set difference, control the external fan of the secondary refrigerant circuit to maintain operation at the set highest gear; Alternatively, when the difference between the temperature of the main power module and the condenser outlet temperature is greater than or equal to the first set difference and less than the second set difference, control the external fan of the secondary refrigerant circuit to increase the gear at the first gear-up speed and not exceed the first set gear at most; Alternatively, when the difference between the temperature of the main power module and the condenser outlet temperature is greater than or equal to the second set difference and less than the third set difference, control the external fan of the secondary refrigerant circuit to maintain the current gear and not exceed the second set gear at most; Alternatively, when the difference between the temperature of the main power module and the condenser outlet temperature is greater than or equal to the third set difference and less than the fourth set difference, control the external fan of the secondary refrigerant circuit to increase the gear at the second gear-up speed and not exceed the third set gear at most; Alternatively, when the difference between the temperature of the main power module and the condenser outlet temperature is greater than or equal to the fourth set difference, control the external fan of the secondary refrigerant circuit to increase the gear at the third gear-up speed and not exceed the fourth set gear at most; Wherein, the first gear-up speed is greater than the second gear-up speed, the second gear-up speed is greater than the third gear-up speed, and the first set gear is greater than the second set gear, the second set gear is greater than the third set gear, and the third set gear is greater than the fourth set gear.

10. A control device for an air conditioning system according to any one of claims 1 to 5, characterized in that, including: An acquisition module for acquiring the temperature of the main power module; A control module, configured to control and adjust the operating parameters of the main refrigerant circuit and / or the secondary refrigerant circuit according to the temperature of the main power module.

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