Control method, control device, double-circulation refrigerating system and storage medium

Abstract

The invention provides a control method, a control device, a double-circulation refrigeration system and a computer readable storage medium. The system energy efficiency in a mixed refrigeration mode can be improved. The control method comprises the steps that operation parameters of the double-circulation refrigerating system are obtained; the superheat degree of the compressor is determined according to the operation parameters of the double-circulation refrigerating system, wherein the superheat degree is the suction superheat degree or the exhaust superheat degree of the compressor; and in the mixed refrigeration mode, the throttling device and the fluorine pump are controlled according to the superheat degree of the compressor.

Description

Technical Field

[0001] The present application relates to but is not limited to the technical field of refrigeration systems, and specifically refers to a control method, a control device, a dual-cycle refrigeration system, and a computer-readable storage medium. Background Art

[0002] At present, based on the characteristics of data center year-round cooling, traditional year-round compressor cooling can no longer meet customers' requirements for data center PUE (Power Usage Effectiveness). Therefore, when the ambient temperature is lower than the room temperature, the solution of using natural cold sources for cooling has been continuously promoted in the industry, especially by connecting a fluorine pump in series with the original compressor refrigeration cycle system as a natural cooling method, that is, using a compressor-fluorine pump dual-circulation refrigeration system to cool the room.

[0003] Among them, the refrigeration modes of the dual-cycle refrigeration system usually include compressor refrigeration mode, mixed refrigeration mode, and fluorine pump refrigeration mode. At present, the operating refrigeration mode is mainly determined based on the outdoor ambient temperature. For example: in summer or other conditions with high outdoor temperatures, the compressor refrigeration mode is mainly used; in winter or other conditions with low outdoor temperatures, the fluorine pump refrigeration mode is mainly used; in spring, autumn and other conditions with relatively moderate outdoor temperatures, the mixed refrigeration mode is mainly used.

[0004] In compressor cooling mode and mixed cooling mode, the opening of the throttling device is controlled according to the superheat of the compressor. In fluorine pump cooling mode, the throttling device remains fully open.

[0005] How to further improve the energy efficiency of the system is the direction that technicians in this field have been working towards. Summary of the invention

[0006] The technical problem to be solved by the present application is to provide a control method, a control device, a dual-cycle refrigeration system and a computer-readable storage medium, which can improve the system energy efficiency in a hybrid refrigeration mode.

[0007] To this end, an embodiment of the present application provides a control method for a dual-cycle refrigeration system, the control method comprising:

[0008] Obtaining operating parameters of the dual-cycle refrigeration system;

[0009] Determining the superheat of the compressor according to the operating parameters of the dual-cycle refrigeration system, wherein the superheat is the suction superheat or the exhaust superheat of the compressor;

[0010] In the mixed refrigeration mode, the throttling device and the fluorine pump are controlled according to the superheat of the compressor.

[0011] The control method provided in the embodiment of the present application controls the fluorine pump and the throttling device according to the superheat of the compressor, rather than simply controlling the throttling device, so that the fluorine pump and the throttling device can control the superheat of the compressor through synergistic effect. This helps to avoid the fluorine pump excessively increasing the refrigerant pressure, which causes the throttling device to excessively throttle and reduce the pressure to ensure that the system has a suitable high and low pressure difference, resulting in wasted pump work, thereby helping to improve the system energy efficiency in the hybrid refrigeration mode.

[0012] Based on the above technical solution, the present application can also be improved as follows.

[0013] In an exemplary embodiment, the throttling device and the fluorine pump are controlled according to the superheat of the compressor, comprising:

[0014] Based on the fact that the superheat of the compressor is greater than a preset target superheat and the difference is greater than a first threshold, the first threshold is greater than 0° C., adjusting the opening of the throttling device according to the preset target superheat so that the superheat of the compressor approaches the preset target superheat;

[0015] Based on the fact that the opening of the throttling device reaches the set maximum opening in the mixed refrigeration mode and the superheat of the compressor is still greater than the preset target superheat and the difference is greater than the first threshold, the throttling device is controlled to maintain the current opening, and the speed of the fluorine pump is adjusted according to the preset target superheat, so that the superheat of the compressor approaches the preset target superheat.

[0016] In an exemplary embodiment, the throttling device and the fluorine pump are controlled according to the superheat of the compressor, comprising:

[0017] Based on the fact that the superheat of the compressor is less than a preset target superheat and the difference is less than a second threshold value, the second threshold value is less than 0° C., adjusting the rotation speed of the fluorine pump according to the preset target superheat so that the superheat of the compressor approaches the preset target superheat degree;

[0018] Based on the fact that the speed of the fluorine pump is reduced to the set minimum speed and the superheat of the compressor is still less than the preset target superheat and the difference is less than the second threshold, the fluorine pump is controlled to maintain the current speed, and the opening of the throttling device is adjusted according to the preset target superheat to make the superheat of the compressor approach the preset target superheat.

[0019] In an exemplary embodiment, the throttling device and the fluorine pump are controlled according to the superheat of the compressor, further comprising:

[0020] Based on the fact that the speed of the fluorine pump is the set minimum speed, the opening of the throttling device is lower than the first set opening, the superheat of the compressor is still lower than the preset target superheat and the difference is lower than the second threshold, the dual-circulation refrigeration system is controlled to switch to the compressor refrigeration mode, and the first set opening is <100%.

[0021] In an exemplary embodiment, the control method further includes:

[0022] In the compressor refrigeration mode, whether to switch to the mixed refrigeration mode is determined according to the operating parameters of the dual-cycle refrigeration system.

[0023] In an exemplary embodiment, the operating parameters of the dual-cycle refrigeration system include: operating parameters of the throttling device, operating parameters of the compressor;

[0024] The determining whether to switch to the mixed refrigeration mode according to the operating parameters of the dual-cycle refrigeration system includes:

[0025] Whether to switch to the mixed refrigeration mode is determined according to the working parameters of the throttling device and the working parameters of the compressor.

[0026] In an exemplary embodiment, the operating parameters of the throttling device include: the opening degree of the throttling device, and the operating parameters of the compressor include: the superheat of the compressor;

[0027] The determining whether to switch to the mixed refrigeration mode according to the working parameters of the throttling device and the working parameters of the compressor includes:

[0028] Based on the fact that the opening of the throttling device is greater than the second set opening and the superheat of the compressor is greater than the set superheat, it is determined that the dual-cycle refrigeration system switches to the mixed refrigeration mode, and the second set opening is less than 100%.

[0029] In an exemplary embodiment, the control method further includes:

[0030] After the dual-cycle refrigeration system is switched from the compressor mode to the mixed refrigeration mode, it is switched back to the compressor refrigeration mode within a preset time, and the set superheat is increased.

[0031] In an exemplary embodiment, the control method further includes:

[0032] In the compressor refrigeration mode, it is determined that the switching conditions for the fluorine pump refrigeration mode are met;

[0033] Control the compressor to reduce the frequency of operation, control the soft start of the fluorine pump, and control the opening of the throttling device according to the superheat of the compressor;

[0034] Based on the compressor frequency being reduced to the first set frequency and the fluorine pump frequency being increased to the second set frequency, the compressor is turned off, and the throttling device is opened to a fully open state, so that the dual-circulation refrigeration system is switched to the fluorine pump refrigeration mode.

[0035] In an exemplary embodiment, the control method further includes:

[0036] In the fluorine pump refrigeration mode, it is determined that the compressor refrigeration mode switching condition is met;

[0037] Controlling the soft start of the compressor, controlling the fluorine pump to reduce the frequency of operation, and reducing the opening of the throttling device to the initial opening of the compressor refrigeration mode, and then controlling the opening of the throttling device according to the superheat of the compressor;

[0038] Based on the compressor frequency increasing to the third set frequency and the fluorine pump frequency decreasing to the fourth set frequency, the fluorine pump is turned off, so that the dual-circulation refrigeration system is switched to the compressor refrigeration mode.

[0039] In an exemplary embodiment, the control method further includes:

[0040] In the process of switching from the compressor cooling mode to the fluorine pump cooling mode, the speed of the outdoor fan is controlled according to the exhaust pressure of the compressor;

[0041] In the process of switching from the fluorine pump cooling mode to the compressor cooling mode, the speed of the outdoor fan is controlled according to the exhaust pressure of the compressor.

[0042] An embodiment of the present application further provides a control device, including a processor and a memory storing a computer program, wherein the processor implements the steps of the control method described in any one of the above embodiments when executing the computer program.

[0043] An embodiment of the present application also provides a dual-cycle refrigeration system, including the control device as described in the above embodiment.

[0044] An embodiment of the present application further provides a computer-readable storage medium storing a computer program, wherein the computer program, when executed by a processor, implements a control method as described in any one of the above embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 A schematic diagram of the structure of a dual-cycle refrigeration system provided in some embodiments of the present application;

[0046] Figure 2 A flow chart of a control method provided in some embodiments of the present application;

[0047] Figure 3 A flow chart of a control method provided by an embodiment of the present application;

[0048] Figure 4 A flow chart of a control method provided by an embodiment of the present application;

[0049] Figure 5 A flow chart of a control method provided by an embodiment of the present application;

[0050] Figure 6 A flowchart of a control method provided for one embodiment of the present application.

[0051] Figure 1 The parts represented by the various reference numerals are listed as follows:

[0052] 1 condenser, 2 outdoor fan, 3 liquid storage tank, 4 fluorine pump, 5 second one-way valve, 6 throttling device, 7 evaporator, 8 indoor fan, 9 first one-way valve, 10 compressor, 11 compressor bypass flow path, 12 fluorine pump bypass flow path. DETAILED DESCRIPTION

[0053] The principles and features of the present application are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present application and are not used to limit the scope of the present application.

[0054] An embodiment of the present application provides a control method for a dual-cycle refrigeration system.

[0055] like Figure 1 As shown, the dual-cycle refrigeration system may include: a compressor 10, a condenser 1, a liquid storage tank 3, a fluorine pump 4, a throttling device 6 and an evaporator 7 connected by pipelines to form a loop; an outdoor fan 2 corresponding to the condenser 1, and an indoor fan 8 corresponding to the evaporator 7; a compressor bypass flow path 11 connected in parallel with the compressor 10 and a first one-way valve 9 provided on the compressor bypass flow path 11; a fluorine pump bypass flow path 12 connected in parallel with the fluorine pump 4 and a second one-way valve 5 provided on the fluorine pump bypass flow path 12. The first one-way valve 9 is configured to conduct unidirectionally in the direction from the outlet of the evaporator 7 to the inlet of the condenser 1. The second one-way valve 5 is configured to conduct unidirectionally in the direction from the outlet of the condenser 1 to the inlet of the evaporator 7. A liquid storage tank 3 may also be provided between the outlet of the condenser 1 and the fluorine pump 4. The evaporator 7 and the indoor fan 8 are located on the indoor side, and the condenser 1 and the outdoor fan 2 are located on the outdoor side. The throttling device 6 may be, but is not limited to, an electronic expansion valve.

[0056] The dual-cycle refrigeration system can be set to have the following three refrigeration modes: compressor refrigeration mode, mixed refrigeration mode, and fluorine pump refrigeration mode. The working principles of each refrigeration mode are as follows:

[0057] Compressor refrigeration mode: the first check valve 9 is closed and the second check valve 5 is open. The refrigerant flows through the compressor 10, the condenser 1, the liquid storage tank 3, the fluorine pump bypass flow path 12, the throttling device 6 and the evaporator 7 in sequence to form a first circulation loop. In this refrigeration mode, the fluorine pump 4 is stopped and the compressor 10 is started to provide power for the refrigeration operation of the system.

[0058] Mixed refrigeration mode: the first check valve 9 is closed, and the second check valve 5 is closed. The refrigerant flows through the compressor 10, the condenser 1, the liquid storage tank 3, the fluorine pump 4, the throttling device 6 and the evaporator 7 in sequence to form a second circulation loop. In this refrigeration mode, the fluorine pump 4 and the compressor 10 are both started, and the outdoor natural cold source is partially used. The fluorine pump 4 can compensate for the circulation power of the refrigerant in the system, reduce the pressure loss of the refrigerant during the circulation process, make the compressor 10 work under the best working condition, reduce the energy consumption of the compressor 10, improve the refrigeration efficiency, and have a certain energy-saving effect.

[0059] Fluorine pump refrigeration mode: the first one-way valve 9 is turned on, and the second one-way valve 5 is turned off. Figure 1 As shown, the refrigerant flows through the compressor bypass flow path 11, the condenser 1, the liquid storage tank 3, the fluorine pump 4, the throttling device 6 and the evaporator 7 in sequence to form a third circulation loop. In this refrigeration mode, the fluorine pump 4 is started and the compressor 10 is stopped, making full use of the outdoor natural cold source, and using the fluorine pump 4 instead of the compressor 10 to provide power for the system cycle. Since the power of the fluorine pump 4 is much smaller than that of the compressor 10, it can significantly reduce the power consumption of the computer room air conditioner, which has a significant energy-saving effect.

[0060] In the related art, in the hybrid refrigeration mode, the throttling device 6 is often used to control the superheat of the compressor 10 to ensure the energy efficiency of the compressor 10. However, since the throttling device 6 and the fluorine pump 4 have opposite effects, the pump power may be wasted, resulting in a decrease in system energy efficiency.

[0061] In some exemplary embodiments, Figure 2 As shown, the control method includes:

[0062] Step S202: obtaining operating parameters of the dual-cycle refrigeration system;

[0063] Step S204: determining the superheat of the compressor according to the operating parameters of the dual-cycle refrigeration system;

[0064] Step S206: In the mixed refrigeration mode, the throttling device and the fluorine pump are controlled according to the superheat of the compressor.

[0065] The superheat is the suction superheat or exhaust superheat of the compressor 10. Since the variation trends of the suction superheat and the exhaust superheat are usually the same, that is, when the suction superheat increases, the exhaust superheat usually increases; when the suction superheat decreases, the exhaust superheat usually decreases. Therefore, in the embodiment of the present application, the superheat of the compressor 10 can be the suction superheat of the compressor 10 or the exhaust superheat of the compressor 10.

[0066] Research has found that the reason why the throttling device 6 and the fluorine pump 4 have opposite effects and may cause the pump work to be wasted is that: since the fluorine pump 4 and the compressor 10 are connected in series in a refrigeration system, the refrigeration mechanism of the mixed refrigeration mode is still the reverse Carnot cycle. The main function of the fluorine pump 4 is to offset the adverse effects of the pressure drop of the liquid pipe on the energy efficiency of the refrigeration system, and to improve the operating energy efficiency of the refrigeration system by reducing the high and low pressure difference. However, if the operation of the fluorine pump 4 not only offsets the adverse effects of the pressure drop of the liquid pipe on the energy efficiency of the refrigeration system, but also increases the refrigerant pressure, that is, excessively reduces the high and low pressure difference of the system, the throttling device 6 needs to reduce the extra pressure of the fluorine pump 4 to ensure that the inlet system has a suitable high and low pressure difference, so as to ensure that the compressor 10 has a suitable suction superheat, and thus has a higher energy efficiency. This leads to the loss of pump work in vain, resulting in a decrease in system energy efficiency. However, in the related art, in the mixed refrigeration mode, it is difficult to avoid the situation of wasted pump work by simply controlling the superheat of the compressor 10 through the throttling device 6, so the system energy efficiency of the mixed mode needs to be further improved.

[0067] The control method provided in the embodiment of the present application controls the fluorine pump 4 and the throttling device 6 according to the superheat of the compressor 10, rather than simply controlling the throttling device 6, so that the fluorine pump 4 and the throttling device 6 can control the superheat of the compressor 10 through synergistic effect. This is beneficial to avoid the fluorine pump 4 excessively increasing the refrigerant pressure, resulting in the throttling device 6 needing to excessively throttle and reduce the pressure to ensure that the system has a suitable high and low pressure difference, resulting in wasted pump work, which is beneficial to improving the system energy efficiency in the hybrid refrigeration mode.

[0068] The specific control method of the fluorine pump 4 and the throttling device 6 is not limited, for example, it can be a linear control method or a PID (Proportional Integral Derivative) control method.

[0069] As mentioned above, in the embodiment of the present application, the superheat of the compressor 10 can be the suction superheat of the compressor 10, or the exhaust superheat of the compressor 10. However, it is understandable that the ideal range of suction superheat (such as 5°C to 10°C) is usually different from the ideal range of exhaust superheat (such as 20°C to 40°C). Therefore, in the control method of the embodiment of the present application, when the superheat is the suction superheat, some parameters preset (such as the following preset target superheat, the first threshold, the second threshold, the set maximum opening in the mixed refrigeration mode, the first set opening, the second set opening, the set superheat, the set superheat increase value and other parameters, of course not limited to these parameters) may be different from some parameters preset when the superheat is the exhaust superheat.

[0070] The following description will be made by taking the superheat of the compressor 10 as the suction superheat as an example.

[0071] In some exemplary embodiments, the throttling device 6 and the fluorine pump 4 are controlled according to the superheat of the compressor 10, including:

[0072] Based on the fact that the superheat of the compressor 10 is greater than the preset target superheat and the difference is greater than the first threshold, the opening of the throttling device 6 is adjusted according to the preset target superheat, so that the superheat of the compressor 10 approaches the preset target superheat;

[0073] Based on the fact that the opening of the throttling device 6 has reached the set maximum opening in the mixed refrigeration mode and the superheat of the compressor 10 is still greater than the preset target superheat and the difference is greater than the first threshold, the throttling device 6 is controlled to maintain the current opening, and the speed of the fluorine pump 4 is adjusted according to the preset target superheat, so that the superheat of the compressor 10 approaches the preset target superheat.

[0074] Among them, the difference = the superheat of the compressor 10 - the preset target superheat > 0°C, the first threshold > 0°C, the size of the first threshold can be reasonably set as needed, and can be in the range of but not limited to 3°C to 8°C, such as 3°C, 4°C, 5°C, 6°C, 7°C, 8°C, etc. The set maximum opening in the mixed refrigeration mode can be 100%, that is, the throttling device 6 reaches a fully open state. The preset target superheat is the superheat of the compressor 10 with relatively ideal energy efficiency, that is: when the superheat of the compressor 10 is the preset target superheat, the energy efficiency of the compressor 10 is higher. Based on the superheat of the compressor 10 being the suction superheat, the preset target superheat can be in the range of but not limited to 5°C to 10°C.

[0075] When the suction superheat of the compressor 10 is greater than the preset target superheat and the difference is greater than the first threshold value, it indicates that the suction superheat of the compressor 10 is seriously higher than the preset target superheat, and thus the system energy efficiency is low. At this time, the suction superheat of the compressor 10 can be reduced by increasing the opening of the throttling device 6, or by increasing the speed of the fluorine pump 4. However, increasing the speed of the fluorine pump 4 will increase the energy consumption of the fluorine pump 4. Therefore, it is preferred to increase the opening of the throttling device 6 to achieve the purpose of reducing the suction superheat of the compressor 10, so that the suction superheat of the compressor 10 can approach the preset target superheat, thereby improving the energy efficiency of the compressor 10 and the system energy efficiency.

[0076] When the opening of the throttling device 6 has increased to the set maximum opening in the hybrid refrigeration mode (such as the fully open state), the suction superheat of the compressor 10 is still seriously higher than the preset target superheat. At this time, the opening of the throttling device 6 cannot be further increased, so the opening of the throttling device 6 remains unchanged, and the suction superheat of the compressor 10 is reduced by increasing the speed of the fluorine pump 4, so that the suction superheat of the compressor 10 can approach the preset target superheat, thereby improving the energy efficiency of the compressor 10. Since the energy efficiency of the compressor 10 contributes much more to the energy efficiency of the system than the fluorine pump 4, although the increase in the speed of the fluorine pump 4 leads to an increase in power consumption, the overall energy efficiency of the system is improved due to the improvement of the energy efficiency of the compressor 10.

[0077] In some exemplary embodiments, the throttling device 6 and the fluorine pump 4 are controlled according to the superheat of the compressor 10, including:

[0078] Based on the fact that the superheat of the compressor 10 is less than the preset target superheat and the difference is less than the second threshold, the rotation speed of the fluorine pump 4 is adjusted according to the preset target superheat, so that the superheat of the compressor 10 approaches the preset target superheat;

[0079] Based on the fact that the speed of the fluorine pump 4 is reduced to the set minimum speed and the superheat of the compressor 10 is still less than the preset target superheat and the difference is less than the second threshold, the fluorine pump 4 is controlled to maintain the current speed, and the opening of the throttling device 6 is adjusted according to the preset target superheat, so that the superheat of the compressor 10 approaches the preset target superheat.

[0080] Wherein, the difference = the superheat of the compressor 10 - the preset target superheat < 0° C., and the second threshold < 0° C. The second threshold can be reasonably set as needed, and can be within the range of -8° C. to -3° C., such as -8° C., -7° C., -6° C., -5° C., -4° C., -4° C., etc., but not limited to.

[0081] When the suction superheat of the compressor 10 is less than the preset target superheat and the difference is less than the second threshold value, it indicates that the suction superheat of the compressor 10 is seriously lower than the preset target superheat. At this time, the suction superheat of the compressor 10 can be increased by reducing the opening of the throttling device 6, or by reducing the rotation speed of the fluorine pump 4. However, reducing the rotation speed of the fluorine pump 4 will reduce the energy consumption of the fluorine pump 4, thereby improving the energy efficiency of the system. Therefore, it is preferred to achieve the purpose of increasing the suction superheat of the compressor 10 by reducing the rotation speed of the fluorine pump 4, so that the suction superheat of the compressor 10 can approach the preset target superheat, thereby improving the energy efficiency of the compressor 10 and the system energy efficiency.

[0082] When the speed of the fluorine pump 4 has been reduced to the set minimum speed, the suction superheat of the compressor 10 is still seriously lower than the preset target superheat. At this time, the speed of the fluorine pump 4 cannot be further reduced, so the speed of the fluorine pump 4 remains unchanged. The suction superheat of the compressor 10 is increased by reducing the opening of the throttling device 6, so that the suction superheat of the compressor 10 can approach the preset target superheat, thereby improving the energy efficiency of the compressor 10.

[0083] In some exemplary embodiments, the throttling device 6 and the fluorine pump 4 are controlled according to the superheat of the compressor 10, further comprising:

[0084] Based on the fact that the speed of the fluorine pump 4 is the set minimum speed, the opening of the throttling device 6 is lower than the first set opening, the superheat of the compressor 10 is still lower than the preset target superheat and the difference is lower than the second threshold value, the dual-circulation refrigeration system is controlled to switch to the compressor refrigeration mode, and the first set opening is <100%.

[0085] The first set opening degree may be in the range of, but not limited to, 50% to 70%, such as 50%, 55%, 60%, 65%, 70%, etc.

[0086] When the speed of the fluorine pump 4 is the set minimum speed, the opening of the throttling device 6 is lower than the first set opening, and the superheat of the compressor 10 is still seriously lower than the preset target superheat, it indicates that the system refrigerant circulation volume is too small and the system refrigeration capacity is insufficient. At this time, the system refrigerant circulation volume can be increased by increasing the opening of the throttling device 6. The operation of the fluorine pump 4 increases the system energy consumption and reduces the system energy efficiency. Therefore, at this time, the control system switches from the mixed refrigeration mode to the compressor refrigeration mode.

[0087] In one embodiment, Figure 3 As shown, the control method includes the following steps:

[0088] Step S302: system operation;

[0089] Step S304: determine whether the system is in the mixed cooling mode, if so, execute step S306, if not, return to step S302;

[0090] Step S306: Obtain the current operating parameters of the system;

[0091] Step S308: determine whether the following conditions are met: the fluorine pump speed is at the set minimum speed, the opening of the throttling device 6 is lower than the first set opening, the suction superheat of the compressor is lower than the preset target superheat and the difference is lower than the second threshold value; if yes, execute step S310; if no, return to step S306;

[0092] Step S310: the control system enters the compressor cooling mode.

[0093] In step S308, the fluorine pump speed is at the set minimum speed, which can also be replaced by: the fluorine pump speed is lower than the set speed threshold. The set speed threshold can be greater than or equal to the set minimum speed.

[0094] In some exemplary embodiments, the control method further includes:

[0095] In the compressor refrigeration mode, whether to switch to the mixed refrigeration mode is determined according to the operating parameters of the dual-cycle refrigeration system.

[0096] As mentioned above, since the fluorine pump 4 and the compressor 10 are connected in series in a refrigeration system, the refrigeration mechanism of the hybrid refrigeration mode is still the reverse Carnot cycle. The main function of the fluorine pump 4 is to offset the adverse effects of the liquid pipe pressure drop on the energy efficiency of the refrigeration system, and to improve the operating efficiency of the refrigeration system by reducing the high and low pressure differences. However, different installation scenarios (such as the length of the refrigerant pipe and the height difference between the internal and external machines) will cause different liquid pipe pressure drops, which will in turn cause changes in the operating range of the hybrid refrigeration mode. In the related art, the operating range of the hybrid refrigeration mode is simply divided according to the outdoor ambient temperature, and the impact of the installation scenario on the operating range of the hybrid refrigeration mode is not taken into account. Therefore, it may not necessarily improve the operating energy efficiency of the system.

[0097] The control method provided in the embodiment of the present application can determine whether to switch to the mixed cooling mode according to the operating parameters of the dual-circulation refrigeration system in the compressor cooling mode, rather than according to the outdoor ambient temperature. Compared with the outdoor ambient temperature, the operating parameters of the dual-circulation refrigeration system can better reflect the system energy efficiency. Therefore, judging whether to switch to the mixed cooling mode according to the operating parameters of the dual-circulation refrigeration system is conducive to further improving the system energy efficiency.

[0098] In addition, the operating parameters of the dual-circulation refrigeration system will be affected by the installation scenario (such as the length of the refrigerant pipe, the height difference between the internal and external units, etc.), that is, the operating parameters of the dual-circulation refrigeration system are related to the installation scenario, and the operating parameters themselves already include the impact of the installation scenario, so there is no need to consider the impact of the installation scenario on the operating range of the hybrid refrigeration mode separately. Therefore, the control method provided in the embodiment of the present application can be applied to different installation scenarios, and the determined operating range of the hybrid refrigeration mode is conducive to effectively improving the operating energy efficiency of the system.

[0099] The control method and the control method for improving energy efficiency in a hybrid refrigeration mode in the aforementioned embodiment do not affect each other and can be implemented separately.

[0100] In some exemplary embodiments, the operating parameters of the dual-cycle refrigeration system include: operating parameters of the throttling device 6 and operating parameters of the compressor 10 .

[0101] Determine whether to switch to the mixed cooling mode according to the operating parameters of the dual-cycle refrigeration system, including:

[0102] Whether to switch to the mixed cooling mode is determined according to the working parameters of the throttling device 6 and the working parameters of the compressor 10 .

[0103] Since the power of the compressor 10 is much higher than that of the fluorine pump 4, the improvement of the system energy efficiency is mainly achieved by improving the energy efficiency of the compressor 10. The working parameters of the compressor 10 can reflect the energy efficiency of the compressor 10, and the working parameters of the throttling device 6 will affect the working parameters of the compressor 10, thereby affecting the energy efficiency of the compressor 10. Therefore, it is more reasonable and reliable to judge whether to switch from the compressor refrigeration mode to the fluorine pump refrigeration mode according to the working parameters of the throttling device 6 and the working parameters of the compressor 10.

[0104] In some exemplary embodiments, the operating parameters of the throttling device 6 include: the opening degree of the throttling device 6 , and the operating parameters of the compressor 10 include: the superheat degree of the compressor 10 .

[0105] Determining whether to switch to the mixed refrigeration mode according to the working parameters of the throttling device 6 and the working parameters of the compressor 10 includes:

[0106] Based on the fact that the opening degree of the throttling device 6 is greater than the second set opening degree and the superheat degree of the compressor 10 is greater than the set superheat degree, it is determined that the dual-cycle refrigeration system is switched to the mixed refrigeration mode.

[0107] Otherwise, it is determined that the dual-cycle refrigeration system continues to operate in the mixed cooling mode.

[0108] The second set opening is less than 100%, and the second set opening can be in the range of 70% to 90%, such as 70%, 75%, 80%, 85%, 90%, 95%, etc. The second set opening can be greater than the first set opening. The set superheat degree is greater than the preset target superheat degree in the above embodiment. For example, the preset target superheat degree can be 5°C, and the set superheat degree here can be 10°C.

[0109] It can be understood that the suction superheat of the compressor 10 can reflect the energy efficiency of the compressor 10. When the suction superheat of the compressor 10 is too high, it can indicate that the energy efficiency of the compressor 10 is low. When the suction superheat of the compressor 10 is too low, it can indicate that the refrigerant circulation volume of the system is too small, which may affect the refrigeration capacity of the system. The suction superheat of the compressor 10 can be adjusted by adjusting the opening of the throttling device 6. Increasing the opening of the throttling device 6 will reduce the suction superheat of the compressor 10; decreasing the opening of the throttling device 6 will increase the suction superheat of the compressor 10.

[0110] Therefore, when the opening of the throttling device 6 is greater than the second set opening and the suction superheat of the compressor 10 is still greater than the set superheat, it indicates that it is no longer possible to increase the opening of the throttling device 6 to reduce the suction superheat of the compressor 10, thereby improving the system energy efficiency. This may be because the piping is too long and the resistance is too large, resulting in too much suction superheat of the compressor 10. Therefore, the fluorine pump 4 can be turned on to increase the pressure, offset the piping pressure drop, and allow more liquid refrigerant to enter the evaporator, thereby reducing the suction superheat of the compressor 10 to improve the system energy efficiency, so it can be determined that the system is switched to the mixed refrigeration mode.

[0111] In some exemplary embodiments, the control method further includes:

[0112] After the dual-cycle refrigeration system switches from the compressor 10 mode to the mixed refrigeration mode, it switches back to the compressor refrigeration mode within a preset time to increase the set superheat.

[0113] The length of the preset time can be set reasonably according to needs and there is no restriction here.

[0114] This can avoid frequent and repeated switching between the compressor cooling mode and the mixed cooling mode in a short period of time, that is, it can avoid frequent mode switching caused by false triggering.

[0115] Among them, the way to increase the set superheat can be: increase the set superheat by a set value (such as 2°C); it can also be: multiply the set superheat by a certain coefficient; or the set superheat can be assigned according to a preset relationship curve or comparison table between the preset time and the set superheat.

[0116] In one embodiment, Figure 4As shown, the control method includes the following steps:

[0117] Step S402: system operation;

[0118] Step S404: determine whether the system is in the compressor cooling mode, if so, execute step S406, if not, return to step S402;

[0119] Step S406: obtaining the current operating parameters of the system;

[0120] Step S408: Determine whether the following conditions are met: the opening of the throttling device is greater than the second set opening, and the suction superheat of the compressor is greater than the set superheat; if so, execute step S410; if not, return to step S406;

[0121] Step S410: the control system enters the hybrid cooling mode.

[0122] In the related art, when the system switches from the compressor refrigeration mode to the fluorine pump refrigeration mode, the compressor 10 is directly turned off and the fluorine pump 4 is turned on. However, it takes a certain amount of time to start the fluorine pump 4, which means that it also takes a certain amount of time for the fluorine pump refrigeration mode to truly play a refrigeration role. This process will lead to insufficient refrigeration capacity of the system. Similarly, when the system switches from the fluorine pump refrigeration mode to the compressor refrigeration mode, the fluorine pump 4 is directly turned off and the compressor 10 is turned on. However, it also takes a certain amount of time to start the compressor 10, which means that it also takes a certain amount of time for the compressor refrigeration mode to truly play a refrigeration role. This process will also lead to insufficient refrigeration capacity of the system.

[0123] In some exemplary embodiments, the control method further includes:

[0124] In the compressor refrigeration mode, it is determined that the switching conditions for the fluorine pump refrigeration mode are met;

[0125] Control the compressor 10 to reduce the frequency of operation, control the fluorine pump 4 to soft start, and control the opening of the throttling device 6 according to the superheat of the compressor 10;

[0126] Based on the frequency of the compressor 10 being reduced to the first set frequency and the frequency of the fluorine pump 4 being increased to the second set frequency, the compressor 10 is turned off, the throttling device 6 is opened to a fully open state, and the dual-circulation refrigeration system is switched to the fluorine pump refrigeration mode.

[0127] The switching condition of the fluorine pump refrigeration mode may be: the outdoor ambient temperature reaches the set temperature corresponding to the switch from the compressor refrigeration mode to the fluorine pump refrigeration mode. The first set frequency may be the minimum operating frequency of the compressor 10. The second set frequency is the frequency corresponding to the starting platform of the fluorine pump 4, that is, the frequency reached when the fluorine pump 4 completes the starting platform. When the frequency of the fluorine pump 4 increases to the second set frequency, it indicates that the fluorine pump 4 has completed the starting platform, that is, the starting process is completed, and the frequency can be adjusted as needed later.

[0128] In this way, during the process of the system switching from the compressor refrigeration mode to the fluorine pump refrigeration mode, the compressor 10 can continue to operate at a low speed, so that there is always liquid refrigerant flowing in the evaporator, and the indoor heat can be absorbed by evaporation. Therefore, the system still has refrigeration capacity, and the refrigeration capacity does not decay much compared to the stable operation process, ensuring that the refrigeration capacity of the system will not fluctuate dramatically during the process of switching from the compressor refrigeration mode to the fluorine pump refrigeration mode.

[0129] When the frequency of the compressor 10 is reduced to the first set frequency and the frequency of the fluorine pump 4 is increased to the second set frequency, it indicates that the fluorine pump 4 has completed the startup platform and can adjust the frequency as needed. The frequency of the compressor 10 has been reduced to the minimum operating frequency, and even if it is turned off, it will not affect the normal operation of the fluorine pump 4. Open the throttling device 6 to the full open state to avoid the throttling device 6 generating resistance and increasing the power consumption of the fluorine pump 4. At this time, the fluorine pump 4 can be regulated according to the logic of the fluorine pump refrigeration mode, that is, the system enters the fluorine pump refrigeration mode.

[0130] Since the compressor 10 and the fluorine pump 4 operate simultaneously during the process of switching from the compressor refrigeration mode to the fluorine pump refrigeration mode, it is equivalent to having a mixed refrigeration mode as a transition during the switching process between the two modes, so that the refrigeration capacity of the system will not fluctuate dramatically.

[0131] Among them, this control method and the control method in the aforementioned embodiment (such as the mixed refrigeration mode control method, the switching method between the compressor refrigeration mode and the mixed refrigeration mode) do not affect each other and can be implemented separately.

[0132] In some embodiments, the control method further includes: in the process of switching from the compressor cooling mode to the fluorine pump cooling mode, controlling the rotation speed of the outdoor fan 2 according to the exhaust pressure of the compressor 10.

[0133] In this way, when the compressor 10 mode is switched to the fluorine pump refrigeration mode, the condenser 1 has a suitable condensing pressure, ensuring that the system still has a high refrigeration capacity when the compressor 10 runs at a low speed.

[0134] In some embodiments, controlling the compressor 10 to operate at a reduced frequency includes: controlling the compressor 10 to gradually reduce the frequency to a first set frequency at a first rate. In other words, the compressor 10 reduces the frequency to the first set frequency at a constant speed. Of course, the compressor 10 can also reduce the frequency to the first set frequency in a non-constant speed manner.

[0135] Controlling the soft start of the fluorine pump 4 includes: controlling the fluorine pump 4 to gradually increase the frequency to the second set frequency at a second rate. In other words, the fluorine pump 4 increases the frequency to the second set frequency at a constant speed. Of course, the fluorine pump 4 can also increase the frequency to the second set frequency at a non-constant speed.

[0136] Opening the throttling device 6 to a fully open state includes: controlling the throttling device 6 to open to a fully open state at a third rate. In other words, the throttling device 6 opens to a fully open state at a constant speed. Of course, the throttling device 6 can also be opened to a fully open state at a non-constant speed.

[0137] The first set frequency is the minimum operating frequency of the compressor 10 , and the second set frequency is the operating frequency corresponding to the starting platform of the fluorine pump 4 .

[0138] In one embodiment, Figure 5 As shown, the control method includes the following steps:

[0139] Step S502: the system operates in a compressor cooling mode;

[0140] Step S504: determine whether the fluorine pump refrigeration mode switching condition is met; if so, execute step S506; if not, return to step S502;

[0141] Step S506: Control the compressor to reduce the frequency to the first set frequency, control the fluorine pump to soft start, control the opening of the throttling device according to the superheat of the compressor, and control the speed of the outdoor fan according to the exhaust pressure of the compressor;

[0142] Step S508: determine whether the fluorine pump is frequency-up to the second set frequency, if yes, execute step S510; if no, return to step S508;

[0143] Step S510: Turn off the compressor, open the throttling device to the fully open state, and control the fluorine pump and the outdoor fan according to the fluorine pump refrigeration mode logic.

[0144] In some exemplary embodiments, the control method further includes:

[0145] In the fluorine pump refrigeration mode, it is determined that the compressor refrigeration mode switching condition is met;

[0146] Control the soft start of the compressor 10, control the fluorine pump 4 to reduce the frequency of operation, and reduce the opening of the throttling device 6 to the initial opening of the compressor cooling mode, and then control the opening of the throttling device 6 according to the superheat of the compressor 10;

[0147] Based on the frequency of the compressor 10 increasing to the third set frequency and the frequency of the fluorine pump 4 decreasing to the fourth set frequency, the fluorine pump 4 is turned off, so that the dual-cycle refrigeration system is switched to the compressor refrigeration mode.

[0148] The compressor refrigeration mode switching condition may be: the outdoor ambient temperature reaches the set temperature corresponding to the switch from the fluorine pump refrigeration mode to the compressor refrigeration mode. The fourth set frequency may be the minimum operating frequency of the fluorine pump 4. The third set frequency may be the frequency corresponding to the start-up platform of the compressor 10, that is, the frequency reached when the compressor 10 completes the start-up platform. When the frequency of the compressor 10 increases to the third set frequency, it indicates that the compressor 10 has completed the start-up platform, that is, the start-up process is completed, and the frequency can be adjusted as needed later.

[0149] In this way, during the process of the system switching from the fluorine pump refrigeration mode to the compressor refrigeration mode, the fluorine pump 4 can continue to operate at a low speed, so that there is always liquid refrigerant flowing in the evaporator, and the indoor heat can be absorbed by evaporation. Therefore, the system still has refrigeration capacity, and the refrigeration capacity does not decay much compared to the stable operation process, ensuring that the refrigeration capacity of the system will not fluctuate dramatically during the process of switching from the fluorine pump refrigeration mode to the compressor refrigeration mode.

[0150] When the frequency of the compressor 10 increases to the third set frequency and the frequency of the fluorine pump 4 decreases to the fourth set frequency, it indicates that the compressor 10 has completed the startup platform and can adjust the frequency as needed. The frequency of the fluorine pump 4 has been reduced to the minimum operating frequency, and even if it is turned off, it will not affect the normal operation of the compressor 10. At this time, the compressor 10 and the throttling device 6 can be regulated according to the logic of the compressor cooling mode, that is, the system enters the compressor cooling mode.

[0151] Since the compressor 10 and the fluorine pump 4 operate simultaneously during the process of switching from the fluorine pump refrigeration mode to the compressor refrigeration mode, it is equivalent to having a mixed refrigeration mode as a transition during the switching process between the two modes, so that the refrigeration capacity of the system will not fluctuate dramatically.

[0152] Among them, this control method and the control methods in the aforementioned embodiments (such as the mixed refrigeration mode control method, the switching method between the compressor refrigeration mode and the mixed refrigeration mode, and the method of switching the compressor refrigeration mode to the fluorine pump refrigeration mode) do not affect each other and can be implemented separately.

[0153] In some embodiments, the control method further comprises:

[0154] In the process of switching from the fluorine pump cooling mode to the compressor cooling mode, the rotation speed of the outdoor fan 2 is controlled according to the exhaust pressure of the compressor 10 .

[0155] In this way, when the fluorine pump refrigeration mode is switched to the compressor refrigeration mode, the condenser 1 has a suitable condensing pressure, ensuring that the system still has a high refrigeration capacity when the fluorine pump 4 runs at a low speed.

[0156] In some embodiments, controlling the compressor 10 to soft start includes: controlling the compressor 10 to gradually increase the frequency to a third set frequency at a fourth rate. In other words, the compressor 10 increases the frequency to the third set frequency at a constant speed. Of course, the compressor 10 may also increase the frequency to the third set frequency in a non-constant speed manner.

[0157] Controlling the fluorine pump 4 to reduce the frequency includes: controlling the fluorine pump 4 to gradually reduce the frequency to the fourth set frequency at the fifth rate. In other words, the fluorine pump 4 reduces the frequency to the fourth set frequency in a constant speed manner. Of course, the fluorine pump 4 can also reduce the frequency to the fourth set frequency in a non-constant speed manner.

[0158] The opening of the throttling device 6 is reduced to the initial opening of the compressor cooling mode, including: controlling the throttling device 6 to reduce the opening to the initial opening of the compressor cooling mode at a sixth rate. In other words, the throttling device 6 is reduced to the initial opening of the compressor cooling mode at a constant speed. Of course, the throttling device 6 can also be reduced to the initial opening of the compressor cooling mode at a non-constant speed.

[0159] In one embodiment, Figure 6 As shown, the control method includes the following steps:

[0160] Step S602: the system operates in a fluorine pump refrigeration mode;

[0161] Step S604: determine whether the compressor cooling mode switching condition is met; if so, execute step S606; if not, return to step S602;

[0162] Step S606: Control the soft start of the compressor, and control the fluorine pump to reduce the frequency to the fourth set frequency, reduce the opening of the throttling device to the initial opening of the compressor cooling mode, and then control the opening of the throttling device according to the superheat of the compressor, and control the speed of the outdoor fan according to the exhaust pressure of the compressor;

[0163] Step S608: Determine whether the compressor frequency is increased to the third set frequency, if yes, execute step S610; if no, return to step S608;

[0164] Step S610: Turn off the fluorine pump and control the compressor, throttling device and outdoor fan according to the compressor cooling mode logic.

[0165] The embodiment of the present application also provides a control device, including a processor and a memory storing a computer program. When the processor executes the computer program, the steps of the fluorine pump starting method in any of the above embodiments are implemented, thereby having all the above-mentioned beneficial effects, which will not be repeated here.

[0166] The processor may be an integrated circuit chip with signal processing capabilities. The above-mentioned processor may be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it may also be a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components. The methods, steps and logic block diagrams disclosed in the embodiments of the present invention may be implemented or executed. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc.

[0167] The embodiment of the present application also provides a dual-circulation refrigeration system, including the control device as described in the above embodiment, and thus has all the above-mentioned beneficial effects, which will not be repeated here.

[0168] The embodiment of the present application further provides a computer-readable storage medium storing a computer program. When the computer program is executed by a processor, the fluorine pump starting method as described in any one of the above embodiments is implemented, thereby having all the above-mentioned beneficial effects, which will not be repeated here.

[0169] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0170] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0171] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like 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 a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0172] In the present application, unless otherwise clearly specified and limited, a first feature being “above” or “below” a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being “above”, “above”, and “above” a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being “below”, “below”, and “below” a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0173] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. 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 may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0174] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

[0175] In any one or more of the above exemplary embodiments, the functions described may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored on a computer-readable medium or transmitted via a computer-readable medium as one or more instructions or codes, and executed by a hardware-based processing unit. A computer-readable medium may include a computer-readable storage medium corresponding to a tangible medium such as a data storage medium, or a communication medium that facilitates a computer program, such as any medium transmitted from one place to another according to a communication protocol. In this way, a computer-readable medium may generally correspond to a non-temporary tangible computer-readable storage medium or a communication medium such as a signal or carrier wave. A data storage medium may be any available medium that can be accessed by one or more computers or one or more processors to retrieve instructions, codes, and / or data structures for implementing the technology described in the present disclosure. A computer program product may include a computer-readable medium.

[0176] By way of example and not limitation, such computer-readable storage media may include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage, flash memory, or any other medium that can be used to store the desired program code in the form of instructions or data structures and can be accessed by a computer. Moreover, any connection may also be referred to as a computer-readable medium. For example, if instructions are transmitted from a website, server or other remote source using coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio and microwave, then coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio and microwave are included in the definition of medium. However, it should be understood that computer-readable storage media and data storage media do not include connections, carrier waves, signals, or other transient (transient) media, but are directed to non-transient tangible storage media. As used herein, disks and optical disks include compact disks (CDs), laser disks, optical disks, digital versatile disks (DVDs), floppy disks, or Blu-ray disks, etc., where disks typically reproduce data magnetically, while optical disks use lasers to reproduce data optically. Combinations of the above should also be included within the scope of computer-readable media.

[0177] For example, instructions may be executed by one or more processors such as one or more digital signal processors (DSPs), general purpose microprocessors, application specific integrated circuits (ASICs), field programmable logic arrays (FPGAs), or other equivalent integrated or discrete logic circuits. Thus, the term "processor" as used herein may refer to any of the above structures or any other structures suitable for implementing the techniques described herein. Additionally, in some aspects, the functionality described herein may be provided within dedicated hardware and / or software modules configured for encoding and decoding, or incorporated in a combined codec. Also, the techniques may be fully implemented in one or more circuits or logic elements.

[0178] The technical solutions of the embodiments of the present disclosure can be implemented in a wide variety of devices or equipment, including wireless mobile phones, integrated circuits (ICs) or a group of ICs (e.g., chipsets). Various components, modules or units are described in the embodiments of the present disclosure to emphasize the functional aspects of the devices configured to perform the described techniques, but they do not necessarily need to be implemented by different hardware units. Instead, as described above, the various units can be combined in a codec hardware unit or provided by a collection of interoperable hardware units (including one or more processors as described above) in combination with suitable software and / or firmware.

Claims

1. A control method for a dual-cycle refrigeration system, characterized in that: The control method comprises: Obtaining operating parameters of the dual-cycle refrigeration system; Determining the superheat of the compressor according to the operating parameters of the dual-cycle refrigeration system, wherein the superheat is the suction superheat or the exhaust superheat of the compressor; In the mixed refrigeration mode, the throttling device and the fluorine pump are controlled according to the superheat of the compressor.

2. The control method according to claim 1, characterized in that: The throttling device and the fluorine pump are controlled according to the superheat of the compressor, including: Based on the fact that the superheat of the compressor is greater than a preset target superheat and the difference is greater than a first threshold, the first threshold is greater than 0° C., adjusting the opening of the throttling device according to the preset target superheat so that the superheat of the compressor approaches the preset target superheat; Based on the fact that the opening of the throttling device reaches the set maximum opening in the mixed refrigeration mode and the superheat of the compressor is still greater than the preset target superheat and the difference is greater than the first threshold, the throttling device is controlled to maintain the current opening, and the speed of the fluorine pump is adjusted according to the preset target superheat, so that the superheat of the compressor approaches the preset target superheat.

3. The control method according to claim 2, characterized in that: The throttling device and the fluorine pump are controlled according to the superheat of the compressor, including: Based on the fact that the superheat of the compressor is less than a preset target superheat and the difference is less than a second threshold value, the second threshold value is less than 0° C., adjusting the rotation speed of the fluorine pump according to the preset target superheat so that the superheat of the compressor approaches the preset target superheat degree; Based on the fact that the speed of the fluorine pump is reduced to the set minimum speed and the superheat of the compressor is still less than the preset target superheat and the difference is less than the second threshold, the fluorine pump is controlled to maintain the current speed, and the opening of the throttling device is adjusted according to the preset target superheat to make the superheat of the compressor approach the preset target superheat.

4. The control method according to claim 3, characterized in that: The throttling device and the fluorine pump controlled according to the superheat of the compressor also include: Based on the fact that the speed of the fluorine pump is the set minimum speed, the opening of the throttling device is lower than the first set opening, the superheat of the compressor is still lower than the preset target superheat and the difference is lower than the second threshold, the dual-circulation refrigeration system is controlled to switch to the compressor refrigeration mode, and the first set opening is <100%.

5. The control method according to any one of claims 1 to 4, characterized in that: Also includes: In the compressor refrigeration mode, whether to switch to the mixed refrigeration mode is determined according to the operating parameters of the dual-cycle refrigeration system.

6. The control method according to claim 5, characterized in that: The operating parameters of the dual-cycle refrigeration system include: operating parameters of the throttling device and operating parameters of the compressor; The determining whether to switch to the mixed refrigeration mode according to the operating parameters of the dual-cycle refrigeration system includes: Whether to switch to the mixed refrigeration mode is determined according to the working parameters of the throttling device and the working parameters of the compressor.

7. The control method according to claim 6, characterized in that: The working parameters of the throttling device include: the opening degree of the throttling device, and the working parameters of the compressor include: the superheat degree of the compressor; The determining whether to switch to the mixed refrigeration mode according to the working parameters of the throttling device and the working parameters of the compressor includes: Based on the fact that the opening of the throttling device is greater than the second set opening and the superheat of the compressor is greater than the set superheat, it is determined that the dual-cycle refrigeration system switches to the mixed refrigeration mode, and the second set opening is less than 100%.

8. The control method according to claim 7, characterized in that: Also includes: After the dual-cycle refrigeration system is switched from the compressor mode to the mixed refrigeration mode, it is switched back to the compressor refrigeration mode within a preset time, and the set superheat is increased.

9. The control method according to claim 1, characterized in that: Also includes: In the compressor refrigeration mode, it is determined that the switching conditions for the fluorine pump refrigeration mode are met; Control the compressor to reduce the frequency of operation, control the soft start of the fluorine pump, and control the opening of the throttling device according to the superheat of the compressor; Based on the compressor frequency being reduced to the first set frequency and the fluorine pump frequency being increased to the second set frequency, the compressor is turned off, and the throttling device is opened to a fully open state, so that the dual-circulation refrigeration system is switched to the fluorine pump refrigeration mode.

10. The control method according to claim 1, characterized in that: Also includes: In the fluorine pump refrigeration mode, it is determined that the compressor refrigeration mode switching condition is met; Controlling the soft start of the compressor, controlling the fluorine pump to reduce the frequency of operation, and reducing the opening of the throttling device to the initial opening of the compressor refrigeration mode, and then controlling the opening of the throttling device according to the superheat of the compressor; Based on the compressor frequency increasing to the third set frequency and the fluorine pump frequency decreasing to the fourth set frequency, the fluorine pump is turned off, so that the dual-circulation refrigeration system is switched to the compressor refrigeration mode.

11. The control method according to claim 9 or 10, characterized in that: Also includes: In the process of switching from the compressor cooling mode to the fluorine pump cooling mode, the speed of the outdoor fan is controlled according to the exhaust pressure of the compressor; In the process of switching from the fluorine pump cooling mode to the compressor cooling mode, the speed of the outdoor fan is controlled according to the exhaust pressure of the compressor.

12. A control device, characterized in that: The system comprises a processor and a memory storing a computer program, wherein when the processor executes the computer program, the steps of the control method according to any one of claims 1 to 11 are implemented.

13. A dual-cycle refrigeration system, characterized in that: Comprising a control device as claimed in claim 12.

14. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the control method according to any one of claims 1 to 11 is implemented.

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