Fluorine pump starting method, control device, dual-cycle refrigeration system and storage medium

Abstract

The application provides a fluorine pump starting method, a control device, a double-circulation refrigeration system and a computer readable storage medium, which can shorten the time required for starting the fluorine pump and improve the success rate of starting the fluorine pump. The fluorine pump starting method comprises the following steps: determining that the condition for starting the fluorine pump by the compressor is met; and starting the fluorine pump by the compressor. In the step of starting the fluorine pump by the compressor, the compressor is started first, then the fluorine pump is started, and the compressor is turned off after the fluorine pump is started.

Description

Technical Field

[0001] This application relates to, but is not limited to, the field of refrigeration system technology, specifically to a refrigerant pump starting method, a control device, a dual-cycle refrigeration system, and a computer-readable storage medium. Background Technology

[0002] Because computer room equipment generates a lot of heat and operates year-round, it requires year-round cooling. To save energy and reduce emissions, many air conditioning manufacturers have developed computer room air conditioners that use a dual-cycle cooling system with both compressors and refrigerant pumps. In summer, when outdoor temperatures are high, compressor cooling is primarily used; in winter, when outdoor temperatures are low, refrigerant pump cooling is primarily used, achieving the goal of energy conservation and emission reduction.

[0003] Due to the significant lifespan advantage of centrifugal pumps, existing dual-cycle refrigeration systems using refrigerant pumps and compressors in computer room air conditioning systems often employ centrifugal pumps as the refrigerant transport device. However, centrifugal pumps are highly susceptible to head loss and flow interruption when the refrigerant vaporizes at the inlet due to the lack of liquid seal; furthermore, the presence of the liquid receiver results in low subcooling at the pump inlet, making it difficult to completely avoid refrigerant pump flow interruptions during extreme environmental changes. At extremely low temperatures, restarting a refrigerant pump after a flow interruption is very difficult.

[0004] Current industry technology typically involves blowing cold air for an extended period before turning on the refrigerant pump, which takes a considerable amount of time. Summary of the Invention

[0005] The technical problem to be solved by this application is to provide a fluorine pump starting method, control device, dual-cycle refrigeration system and computer-readable storage medium, which can shorten the time required to start the fluorine pump and improve the starting success rate of the fluorine pump.

[0006] Therefore, this application provides a refrigerant pump start-up method for a dual-cycle refrigeration system, the refrigerant pump start-up method comprising:

[0007] The conditions for starting the refrigerant pump with the compressor auxiliary have been met;

[0008] The fluorine pump is started with the assistance of a compressor;

[0009] The step of starting the fluorine pump with the assistance of the compressor includes: starting the compressor first, then starting the fluorine pump, and then turning off the compressor after the fluorine pump starts.

[0010] The refrigerant pump starting method provided in this application allows for the initial determination of whether the conditions for compressor-assisted starting of the refrigerant pump are met when starting the pump. When the conditions are met, the compressor can be used to assist in starting the pump. Starting the compressor first generates higher pressure within the system, rapidly increasing the pressure in the receiver liner and at the pump inlet. This raises the saturation temperature of the refrigerant in the receiver liner, preventing it from exceeding its saturation temperature and thus avoiding refrigerant vaporization. The pump is then started, and the compressor continues to operate during the start-up process, maintaining the refrigerant pressure in the receiver liner and at the pump inlet. This prevents a sudden pressure drop due to compressor shutdown during start-up, which could cause refrigerant vaporization and affect the pump's start-up process. The compressor is only shut off after the pump has started successfully.

[0011] Compared to the method of using a condenser fan to continuously cool the refrigerant in the receiver tank until it is too cold to vaporize during startup, this method uses the compressor to quickly increase the pressure in the receiver tank and at the refrigerant pump inlet, thus preventing refrigerant vaporization. Since the pressure response is significantly faster than the temperature response in the above process, this method can shorten the startup time of the refrigerant pump.

[0012] Compared to stopping the compressor after it has been running for a period of time and then starting the refrigerant pump, this solution allows the compressor and refrigerant pump to run together for a period of time, and only shuts off the compressor after the refrigerant pump has started successfully. This avoids the sudden pressure drop in the system caused by the compressor suddenly shutting off before the refrigerant pump starts, which would cause the refrigerant to vaporize and affect the successful start of the refrigerant pump, thus improving the start-up success rate of the refrigerant pump.

[0013] Based on the above technical solution, the following improvements can be made to this application.

[0014] In an exemplary embodiment, starting the compressor first, then starting the refrigerant pump, and then shutting down the compressor after the refrigerant pump has started includes:

[0015] Start the compressor;

[0016] After the compressor meets the first set operating conditions, the refrigerant pump is started, so that the refrigerant pump and the compressor run together;

[0017] The compressor is shut down based on the fact that the fluorine pump meets the second set operating conditions.

[0018] In one exemplary embodiment, the first set operating conditions include at least one of the following:

[0019] The difference between the compressor's discharge pressure and suction pressure reaches the set pressure difference range.

[0020] The compressor runs for a period of time that reaches a first set time range.

[0021] In one exemplary embodiment, the second set operating conditions include at least one of the following:

[0022] The head of the fluorine pump reaches the set head range;

[0023] The fluorine pump operates for a duration that reaches the second set time range.

[0024] In an exemplary embodiment, before starting the fluorine pump and enabling it to operate together with the compressor, the fluorine pump starting method further includes:

[0025] Control the speed of the condenser fan;

[0026] If the third set operating condition is met, the step of starting the refrigerant pump and making the refrigerant pump run together with the compressor is executed.

[0027] In one exemplary embodiment, controlling the rotational speed of the condenser fan includes:

[0028] Before the compressor meets the first set operating conditions, the speed of the condenser fan is controlled to the first set speed;

[0029] Based on the compressor meeting the first set operating conditions, the speed of the condenser fan is controlled to a second set speed, which is higher than the first set speed.

[0030] In one exemplary embodiment, the third set operating condition includes: the condenser fan operates at the second set speed for a duration that reaches a third set duration range.

[0031] In one exemplary embodiment, during the step of starting the compressor, the compressor is controlled to start at a third set speed; and / or, during the step of starting the refrigerant pump, the refrigerant pump is controlled to start at a fourth set speed.

[0032] In one exemplary embodiment, the compressor-assisted start-up conditions for the refrigerant pump include at least one of the following:

[0033] The outdoor ambient temperature is within the set temperature range;

[0034] The fluorine pump failed to start automatically.

[0035] This application also provides a control device, including a processor and a memory storing a computer program, wherein the processor executes the computer program to implement the steps of the fluorine pump starting method as described in any of the above embodiments.

[0036] This application also provides a dual-cycle refrigeration system, including the control device described in the above embodiments.

[0037] This application also provides a computer-readable storage medium storing a computer program, characterized in that, when the computer program is executed by a processor, it implements the fluorine pump starting method as described in any of the above embodiments. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the structure of a dual-cycle refrigeration system provided in some embodiments of this application;

[0039] Figure 2 A schematic flowchart illustrating a fluorine pump start-up method provided in some embodiments of this application;

[0040] Figure 3 A schematic flowchart of a fluorine pump start-up method provided in one embodiment of this application;

[0041] Figure 4 This is a schematic flowchart of a fluorine pump start-up method provided in another embodiment of this application.

[0042] Figure 1 The list of components represented by each number is as follows:

[0043] 1. Condenser, 2. Condenser fan, 3. Liquid receiver, 4. Fluorine pump, 5. Second check valve, 6. Throttling device, 7. Evaporator, 8. Evaporator fan, 9. First check valve, 10. Compressor, 11. First bypass path, 12. Second bypass path. Detailed Implementation

[0044] The principles and features of this application are described below with reference to the accompanying drawings. The examples given are only for explaining this application and are not intended to limit the scope of this application.

[0045] This application provides a method for starting a refrigerant pump for a dual-cycle refrigeration system.

[0046] like Figure 1As shown, the dual-cycle refrigeration system may include: a compressor 10, a condenser 1, a liquid receiver 3, a refrigerant pump 4, a throttling device 6, and an evaporator 7 connected by pipelines to form a loop; a condenser fan 2 corresponding to the condenser 1 and an evaporator fan 8 corresponding to the evaporator 7; a first bypass flow path 11 connected in parallel with the compressor 10 and a first one-way valve 9 provided in the first bypass flow path 11; a second bypass flow path 12 connected in parallel with the refrigerant pump 4 and a second one-way valve 5 provided in the second bypass flow path 12. The first one-way valve 9 is configured to unidirectionally open 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 unidirectionally open in the direction from the outlet of the condenser 1 to the inlet of the evaporator 7. A liquid receiver 3 may also be provided between the outlet of the condenser 1 and the refrigerant pump 4. The evaporator 7 and the evaporator fan 8 are located on the indoor side, and the condenser 1 and the condenser fan 2 are located on the outdoor side. The throttling device 6 may be, but is not limited to, an electronic expansion valve.

[0047] The dual-cycle refrigeration system can be set to have the following three refrigeration modes: compressor refrigeration mode, hybrid refrigeration mode, and refrigerant pump refrigeration mode. The working principle of each refrigeration mode is as follows:

[0048] Compressor refrigeration mode: First one-way valve 9 is closed, and second one-way valve 5 is open. The refrigerant flows sequentially through compressor 10, condenser 1, liquid receiver 3, second bypass path 12, throttling device 6, and evaporator 7, forming the first circulation loop. In this refrigeration mode, refrigerant pump 4 stops, and compressor 10 starts, providing power for the system's refrigeration operation.

[0049] Hybrid refrigeration mode: The first one-way valve 9 is closed, and the second one-way valve 5 is closed. The refrigerant flows sequentially through the compressor 10, condenser 1, receiver 3, refrigerant pump 4, throttling device 6, and evaporator 7, forming a second circulation loop. In this refrigeration mode, both the refrigerant pump 4 and the compressor 10 are started, partially utilizing outdoor natural cold sources. The refrigerant pump 4 can compensate for the circulation dynamics of the refrigerant in the system, reducing the pressure loss of the refrigerant during circulation, allowing the compressor 10 to operate under optimal conditions, reducing the energy consumption of the compressor 10, improving refrigeration efficiency, and achieving a certain energy-saving effect.

[0050] Refrigerant pump refrigeration mode: First one-way valve 9 is open, second one-way valve 5 is closed. For example... Figure 1 As shown, the refrigerant flows sequentially through the first bypass path 11, condenser 1, liquid receiver 3, refrigerant pump 4, throttling device 6, and evaporator 7, forming a third circulation loop. In this cooling mode, refrigerant pump 4 starts while compressor 10 stops, making full use of the outdoor natural cold source. Refrigerant pump 4 replaces compressor 10 to provide power for the system circulation. Since the power of refrigerant pump 4 is much smaller than that of compressor 10, the power consumption of the computer room air conditioner can be significantly reduced, resulting in significant energy-saving effects.

[0051] The study found that the refrigerant vaporization was caused by the following: In the refrigerant pump refrigeration mode, the liquid receiver 3 was not full. At the gas-liquid interface, the refrigerant was in a saturated state, and the refrigerant temperature was equal to the saturation temperature at the corresponding pressure. When the refrigerant pressure upstream of the refrigerant pump dropped rapidly (such as when the condenser fan was turned up rapidly, causing a drop in condensing pressure), the saturation temperature of the refrigerant in the liquid receiver 3 also dropped rapidly. However, the rate of temperature decrease in the liquid receiver 3 was significantly lower than the rate of pressure decrease, causing the refrigerant in the liquid receiver 3 to become in a state with a temperature higher than the saturation temperature, thus evaporating and producing a gas-liquid two-phase system.

[0052] In related technologies, blowing cold air for a long time is used to reduce the refrigerant temperature in the storage tank 3 through prolonged heat exchange, so that the refrigerant temperature in the storage tank 3 is lower than the saturation temperature corresponding to the rapid pressure drop during the start-up of the fluorine pump, thereby preventing refrigerant vaporization and enabling the fluorine pump 4 to start; or after the fluorine pump has stopped flowing due to vaporization, blowing cold air for a long time can fully cool the gas and liquid phases of the refrigerant in the storage tank 3, returning it to a saturated state, so that the fluorine pump 4 can start, but the start-up time of the fluorine pump 4 is relatively long.

[0053] In some embodiments of this application, such as Figure 2 As shown, the fluorine pump start-up method includes:

[0054] Step S202: Determine that the conditions for starting the compressor auxiliary refrigerant pump are met;

[0055] Step S204: Start the refrigerant pump with the aid of the compressor, wherein starting the refrigerant pump with the aid of the compressor includes: starting the compressor first, then starting the refrigerant pump, and shutting down the compressor after the refrigerant pump starts.

[0056] The refrigerant pump starting method provided in this application, when it is necessary to start the refrigerant pump 4 (e.g., receiving a refrigerant pump start command or detecting a refrigerant pump flow interruption), can first determine whether the conditions for compressor-assisted starting of the refrigerant pump are met. When it is determined that the conditions for compressor-assisted starting of the refrigerant pump are met, the compressor 10 can be used to assist in starting the refrigerant pump 4. Since the compressor 10 starts first, it can generate higher pressure in the system, thereby rapidly increasing the pressure at the inlet of the liquid receiver 3 and the refrigerant pump 4, which can increase the saturation temperature of the refrigerant in the liquid receiver 3, preventing the refrigerant temperature in the liquid receiver 3 from exceeding the saturation temperature, thus helping to prevent refrigerant vaporization; on this basis, the refrigerant pump 4 is started, and the compressor 10 continues to run during the start-up process of the refrigerant pump 4, which can maintain the refrigerant pressure in the liquid receiver 3 and at the inlet of the refrigerant pump 4, preventing the refrigerant from vaporizing due to a sudden pressure drop caused by the compressor 10 shutting down during the start-up process of the refrigerant pump 4. The compressor 10 is only shut off after the refrigerant pump 4 has started.

[0057] Compared to the method of starting the refrigerant pump 4 by blowing cold air for a long time, this method can quickly increase the pressure at the inlet of the refrigerant pump 4 by starting the compressor 10, thereby preventing refrigerant vaporization. Since the pressure response is significantly faster than the temperature response, this method can shorten the start-up time of the refrigerant pump 4.

[0058] Compared to stopping compressor 10 after it has been running for a period of time and then starting refrigerant pump 4, this solution allows compressor 10 and refrigerant pump 4 to run together for a period of time. Compressor 10 is only turned off after refrigerant pump 4 has started successfully. This avoids the sudden pressure drop in the system caused by compressor 10 suddenly turning off before refrigerant pump 4 starts, which would cause refrigerant vaporization and affect the successful start of refrigerant pump 4. This improves the start-up success rate of refrigerant pump 4.

[0059] The refrigerant pump starting method provided in this application can be used to start the refrigerant pump 4 after a flow interruption, or to start the refrigerant pump 4 during normal startup. For example, it can be used to restart the refrigerant pump due to a flow interruption during refrigerant pump cooling mode operation, or to start the refrigerant pump when the refrigerant pump cooling mode is activated. Therefore, determining whether the compressor-assisted starting condition for the refrigerant pump is met can be based on determining that the refrigerant pump is interrupted in the refrigerant pump cooling mode, or it can be based on receiving a refrigerant pump start command. As long as the compressor-assisted starting condition for the refrigerant pump is met when the refrigerant pump 4 needs to be started, the compressor 10 can assist in starting the refrigerant pump 4, enabling the refrigerant pump 4 to start quickly and successfully. When the compressor-assisted starting condition for the refrigerant pump is not met, the refrigerant pump 4 can be started through an automatic start method.

[0060] As for the self-starting method of refrigerant pump 4, it can be the conventional starting method of refrigerant pump 4. For example, refrigerant pump 4 can start directly when the machine is turned on; or, after the flow of refrigerant pump 4 is interrupted, condenser fan 2 can run for a period of time before refrigerant pump 4 starts.

[0061] In some exemplary embodiments, the conditions for compressor-assisted start of the refrigerant pump include at least one of the following: the outdoor ambient temperature is within the set temperature range; or the refrigerant pump 4 fails to start automatically.

[0062] In other words, when the outdoor ambient temperature is within the set range, the refrigerant pump 4 can be started with the assistance of compressor 10. When the refrigerant pump 4 fails to start automatically, it can also be started with the assistance of compressor 10. When the outdoor ambient temperature is within the set range and the refrigerant pump 4 fails to start automatically, the refrigerant pump 4 can be started with the assistance of compressor 10.

[0063] The set temperature range can be, but is not limited to, less than or equal to the preset temperature. The outdoor ambient temperature can be denoted as Th, and the preset temperature can be denoted as Th_s. Therefore, the condition for the compressor to start the refrigerant pump is: Th ≤ Th_s. The preset temperature can be set reasonably as needed, and can be, but is not limited to, a range from -30℃ to 0℃, such as -30℃, -25℃, -20℃, -15℃, -10℃, -5℃, 0℃, etc.

[0064] Because it is difficult to restart the refrigerant pump 4 after it stops flowing under ultra-low temperature conditions, the compressor 10 can be used to assist in starting the refrigerant pump 4, thereby improving the success rate of starting the refrigerant pump 4 and shortening the time required for starting the refrigerant pump 4.

[0065] When the refrigerant pump 4 fails to start normally via its automatic start-up mode, it indicates that the refrigerant pump 4 is difficult to start normally. In this case, the compressor 10 can be used to assist in starting the refrigerant pump 4, thereby improving the success rate of starting the refrigerant pump 4 and reducing the required time.

[0066] For the conditions for starting the refrigerant pump with the compressor: the above conditions can be used individually, in combination and in an "or" manner, or in combination and in an "and" manner.

[0067] In some exemplary embodiments, compressor 10 is started first, followed by refrigerant pump 4, and compressor 10 is shut down after refrigerant pump 4 starts, including:

[0068] Start compressor 10;

[0069] After the compressor 10 meets the first set operating conditions, start the refrigerant pump 4 so that the refrigerant pump 4 runs together with the compressor 10;

[0070] Based on the fact that the refrigerant pump 4 meets the second set operating conditions, the compressor 10 is shut down.

[0071] Once the compressor 10 meets the first set operating conditions, it indicates that a certain pressure difference has been established between the inlet and outlet of the compressor 10. Therefore, the refrigerant pressure in the liquid receiver 3 and at the inlet of the refrigerant pump 4 can meet the requirements and will not cause refrigerant vaporization, thus affecting the start-up of the refrigerant pump 4. Therefore, the refrigerant pump 4 can be started, allowing the refrigerant pump 4 to operate together with the compressor 10.

[0072] When the refrigerant pump 4 meets the second set operating conditions, it indicates that the refrigerant pump 4 has been successfully started and is running stably. It will not experience flow interruption due to the shutdown of the compressor 10. Therefore, the compressor 10 can be shut down at this time, and the shutdown of the compressor 10 will not affect the normal operation of the refrigerant pump 4.

[0073] In some examples, the first set operating condition includes: the difference between the discharge pressure and the intake pressure of the compressor 10 reaches a set pressure difference range.

[0074] When the difference between the discharge pressure and suction pressure of compressor 10 reaches the set pressure difference range, it indicates that a certain pressure difference has been established between the inlet and outlet of compressor 10. Therefore, the pressure at the inlet of the liquid receiver 3 and the refrigerant pump 4 meets the requirements and will not cause refrigerant vaporization, thus affecting the start-up of the refrigerant pump 4. Since this scheme can directly indicate that the system pressure meets the requirements, its accuracy is high.

[0075] The difference between the discharge pressure and the suction pressure of the compressor 10 is denoted as △P. The set pressure difference range can be greater than the preset pressure difference, which can be denoted as △P_s. The first set operating condition can be △P > △P_s. △P_s can be set reasonably as needed, and can be in the range of 0.2MPa to 0.5MPa, such as 0.2MPa, 0.3MPa, 0.4MPa, 0.5MPa, etc.

[0076] In other examples, the first set operating condition includes: the operating time of compressor 10 reaches a first set duration range.

[0077] In other words, instead of using the difference between the discharge pressure and suction pressure ΔP of compressor 10 as the criterion for determining whether compressor 10 meets the first set operating conditions, the running time of compressor 10 is used as the criterion. Since there is a correlation between the running time of compressor 10 and ΔP, when the running time of compressor 10 reaches the first set time range, the difference between the discharge pressure and suction pressure ΔP of compressor 10 can generally reach the set pressure difference range. Therefore, the running time of compressor 10 can also be used as the criterion for determining whether compressor 10 meets the first set operating conditions, and the control logic is simpler.

[0078] The running time of compressor 10 can be denoted as ty. The first set time range can be greater than or equal to the first set time. The first set time can be denoted as t1. Then the first set running condition can be ty≥t1. t1 can be set reasonably as needed, and can be in the range of 10s to 120s, such as 10s, 30s, 60s, 90s, 120s, etc.

[0079] In other examples, the first set running condition can also be: △P > △P_s and ty ≥ t1. Alternatively, the first set running condition can also be: △P > △P_s or ty ≥ t1.

[0080] In other words, for the first set operating condition: the conditions in the above example can be used individually, or combined and used in an "or" manner, or combined and used in an "and" manner.

[0081] In some examples, the second set operating condition includes: the head of the fluorine pump 4 reaches the set head range.

[0082] When the head of the refrigerant pump 4 reaches the set head range, it indicates that the refrigerant pump 4 has been operating stably and is unlikely to experience head loss that could cause flow interruption. Therefore, the compressor 10 can be turned off, and turning off the compressor 10 will not affect the normal operation of the refrigerant pump 4.

[0083] The head of the fluorine pump 4 can be denoted as △H. The set head range can be greater than the preset head, which can be denoted as △H_s. The second set operating condition can be △H > △H_s. △H_s can be set reasonably as needed, and can be within the range of 150KPa to 500KPa, such as 150KPa, 200KPa, 300KPa, 400KPa, 500KPa, etc.

[0084] In other examples, the second set operating conditions include: the operating time of the fluorine pump 4 reaches a second set time range.

[0085] In other words, instead of using the head of the refrigerant pump 4 as the criterion for determining whether it meets the second set operating conditions, the running time of the refrigerant pump 4 is used. Since there is a correlation between the running time of the refrigerant pump 4 and ΔH, when the running time of the refrigerant pump 4 is within the second set time range, the head ΔH of the refrigerant pump 4 can generally reach the set head range. Therefore, the running time of the refrigerant pump 4 can also be used as the criterion for determining whether it meets the second set operating conditions, and the control logic is simpler.

[0086] The running time of the fluorine pump 4 can be denoted as tf. The second set time range can be greater than or equal to the second set time. The second set time can be denoted as t2. The second set running condition can be tf≥t2. t2 can be set reasonably as needed, and can be in the range of 10s to 120s, such as 10s, 30s, 60s, 90s, 120s, etc.

[0087] In other examples, the second set running condition can also be: △H > △H_s and tf ≥ t2. Alternatively, the second set running condition can also be: △H > △H_s or tf ≥ t2.

[0088] In other words, for the second set of operating conditions: the conditions in the above examples can be used individually, or combined and used in an "or" manner, or combined and used in an "and" manner.

[0089] In some exemplary embodiments, before starting the refrigerant pump 4 and enabling it to operate together with the compressor 10, the refrigerant pump starting method further includes:

[0090] Control the speed of condenser fan 2;

[0091] Based on the establishment of the third set operating conditions, the step of starting the refrigerant pump 4 and making the refrigerant pump 4 run together with the compressor 10 is executed.

[0092] The rotational speed of condenser fan 2 affects the condensing pressure of condenser 1, which in turn affects the refrigerant pressure in receiver 3 and the refrigerant pressure at the inlet of refrigerant pump 4. The rotational speed of condenser fan 2 is negatively correlated with the pressure at the inlet of refrigerant pump 4. A higher rotational speed of condenser fan 2 results in a lower condensing pressure in condenser 1, and consequently, lower refrigerant pressure in receiver 3 and at the inlet of refrigerant pump 4. This may adversely affect the startup of refrigerant pump 4. However, to ensure cooling efficiency, condenser fan 2 needs to be turned on in refrigerant pump cooling mode.

[0093] Therefore, in order to avoid the start-up of the condenser fan 2 affecting the normal start-up of the refrigerant pump 4, this solution controls the speed of the condenser fan 2 before the refrigerant pump 4 starts. The operation of the compressor 10 can overcome the adverse effects of the condenser fan 2, ensuring the normal start-up and operation of the refrigerant pump 4, and avoiding the refrigerant pump 4 from being interrupted due to the condenser fan 2 starting after the refrigerant pump 4 has started.

[0094] When the third set operating condition is met, it indicates that the operation of the condenser fan 2 will not affect the start-up of the refrigerant pump 4. Therefore, the refrigerant pump 4 can be started so that it can run together with the compressor 10.

[0095] In some exemplary embodiments, controlling the rotational speed of the condenser fan 2 includes:

[0096] Before the compressor 10 meets the first set operating conditions, the speed of the condenser fan 2 is controlled to the first set speed;

[0097] Based on the compressor 10 meeting the first set operating conditions, the speed of the condenser fan 2 is controlled to the second set speed.

[0098] The second set speed is higher than the first set speed.

[0099] Since refrigerant pump refrigeration typically operates in low outdoor ambient temperatures, the condensing pressure of condenser 1 also affects the startup of compressor 10. If the condensing pressure of condenser 1 is too low, it becomes difficult to establish a pressure difference between the inlet and outlet of compressor 10, leading to startup difficulties. Therefore, before compressor 10 meets the first set operating conditions, i.e., during compressor 10 startup, controlling the speed of condenser fan 2 to be relatively low (the first set speed can be 0, or a low speed higher than 0, such as the minimum speed of condenser fan 2) can prevent the condensing pressure in condenser 1 from being too low, thus avoiding the difficulty in establishing a pressure difference between the inlet and outlet of condenser 1. This ensures that the suction and discharge pressure difference is established, facilitating rapid startup of compressor 10. The controlled speed of condenser fan is the first set speed, which can be an increase, a decrease, or a constant speed, depending on the current speed of condenser fan 2 before this step. If condenser fan 2 is running and its speed is higher than the first set speed before this step, this step will cause the speed of condenser fan 2 to decrease. If the condenser fan 2 is running and its speed is equal to the first set speed before this step is performed, this step will cause the speed of the condenser fan 2 to remain unchanged. If the condenser fan 2 is stopped or running and its speed is lower than the first set speed before this step is performed, this step will cause the speed of the condenser fan 2 to increase.

[0100] When compressor 10 meets the first set operating conditions, it indicates that compressor 10 has successfully started and the suction and discharge pressure difference has been established. At this time, the speed of condenser fan 2 can be increased without excessively affecting the refrigerant pressure at the inlet of liquid receiver 3 and refrigerant pump 4. Therefore, refrigerant pump 4 can start normally and operate stably after compressor 10 is turned off. When the first set speed is 0, the second set speed can be the minimum speed of condenser fan 2. When the first set speed is a low speed higher than 0 (such as the minimum speed of condenser fan 2), the second set speed can be greater than the minimum speed of condenser fan 2.

[0101] In some exemplary embodiments, the third set operating condition includes: the condenser fan 2 operates at the second set speed for a duration that reaches the third set duration range.

[0102] The running time of the condenser fan 2 can be denoted as tl. The third set time range can be greater than or equal to the third set time. The third set time can be denoted as t3. The third set running condition can be tl≥t3. t3 can be set reasonably as needed, and can be in the range of 10s to 120s, such as 10s, 30s, 60s, 90s, 120s, etc.

[0103] In some exemplary embodiments, during the step of starting the compressor 10, the compressor 10 is controlled to start at a third set speed. The third set speed can be the minimum speed of the compressor 10, or a low speed greater than the minimum speed of the compressor 10.

[0104] This not only facilitates the rapid and stable start-up of compressor 10, but also helps reduce energy consumption while meeting the start-up requirements of refrigerant pump 4.

[0105] In some exemplary embodiments, during the step of starting the fluorine pump 4, the fluorine pump 4 is controlled to start at a fourth preset speed. The fourth preset speed can be the minimum speed of the fluorine pump 4, or a low speed greater than the minimum speed of the fluorine pump 4.

[0106] In this way, the refrigerant pump 4 can start at a low speed first, and then switch to high speed after the compressor 10 is turned off. This facilitates a smooth start-up of the refrigerant pump 4 and its gradual attainment of normal operating conditions. Starting at a low speed reduces the impact and pressure changes during startup, improving the safety and reliability of the equipment.

[0107] In some exemplary embodiments, the refrigerant pump starting method further includes controlling the evaporator fan 8 to operate at a fifth set speed during the process of starting the refrigerant pump 4 with the assistance of the compressor 10. The fifth set speed is a relatively high speed, which can be the rated speed of the evaporator fan 8.

[0108] During the process of compressor 10 assisting in starting refrigerant pump 4, evaporator fan 8 operates at the fifth set speed, which can accelerate the evaporation of refrigerant in evaporator 7 and facilitate the rapid start of compressor 10.

[0109] In some exemplary embodiments, the refrigerant pump starting method further includes controlling the throttling device 6 to be fully open during the process of starting the refrigerant pump 4 with the assistance of the compressor 10.

[0110] Keeping the throttling device 6 fully open can reduce the resistance generated by the throttling device 6 during the start-up of the fluorine pump 4.

[0111] When compressor 10 is turned off, the operating parameters of refrigerant pump 4, condenser fan 2 and evaporator fan 8 can be freely adjusted according to the refrigerant pump refrigeration mode.

[0112] In one embodiment, such as Figure 3 As shown, the fluorine pump start-up method includes the following steps:

[0113] Step S302: Fluorine pump interruption detected.

[0114] Step S304: Determine whether Th > Th_s is true. That is, determine whether the outdoor ambient temperature Th is greater than the preset temperature Th_s. If not, proceed to step S306; if yes, proceed to step S318.

[0115] Step S306: Start the compressor at the third set speed and control the condenser fan speed to the first set speed.

[0116] Step S308: Determine whether △P > △P_s is true; if yes, proceed to step S310; if no, return to step S308.

[0117] Step S310: Control the speed of the condenser fan to the second set speed, which is greater than the first set speed.

[0118] Step S312: After the condenser fan runs at the second set speed for the third set time, the refrigerant pump is started at the fourth set speed.

[0119] Step S314: Determine whether △H>△H_s is true; if yes, proceed to step S316; if no, return to step S314.

[0120] Step S316: Turn off the compressor.

[0121] Step S318: Start the fluorine pump in self-starting mode.

[0122] In another embodiment, such as Figure 4 As shown, the fluorine pump start-up method includes the following steps:

[0123] Step S402: Fluorine pump interruption detected.

[0124] Step S404: Determine whether Th > Th_s is true. That is, determine whether the outdoor ambient temperature Th is greater than the preset temperature Th_s. If not, proceed to step S406; if yes, proceed to step S420.

[0125] Step S406: Start the compressor at the third set speed and control the condenser fan speed to the first set speed.

[0126] Step S408: After the compressor has run for a first set time, control the speed of the condenser fan to the second set speed.

[0127] Step S410: After the condenser fan runs at the second set speed for the third set time, the refrigerant pump is started at the fourth set speed.

[0128] Step S412: After the refrigerant pump has run for the second set time, turn off the compressor.

[0129] Step S414: Start the refrigerant pump in automatic mode.

[0130] This application also provides a control device, including a processor and a memory storing a computer program. When the processor executes the computer program, it implements the steps of the fluorine pump starting method as described in any of the above embodiments, and thus has all the above-mentioned beneficial effects, which will not be repeated here.

[0131] The processor may be an integrated circuit chip with signal processing capabilities. The aforementioned processor can be a general-purpose processor, including a Central Processing Unit (CPU), a Network Processor (NP), etc.; it can also be a Digital Signal Processor (DSP), an Application-Specific Integrated Circuit (ASIC), an On-Premises Programmable Gate Array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. It can implement or execute the methods, steps, and logic block diagrams disclosed in the embodiments of this invention. The general-purpose processor can be a microprocessor or any conventional processor.

[0132] This application also provides a dual-cycle refrigeration system, including the control device as described in the above embodiments, and thus has all the above-mentioned beneficial effects, which will not be repeated here.

[0133] This application also provides a computer-readable storage medium storing a computer program. When the computer program is executed by a processor, it implements the fluorine pump starting method as described in any of the above embodiments, and thus has all the above-mentioned beneficial effects, which will not be repeated here.

[0134] In summary, the refrigerant pump starting method, control device, dual-cycle refrigeration system, and computer-readable storage medium provided in this application embodiment employ an auxiliary starting method to start the refrigerant pump, in which the compressor runs first, the refrigerant pump runs simultaneously, and then the compressor is shut down. This auxiliary starting method has the advantages of high success rate and fast speed.

[0135] Specifically, the compressor can be started at the lowest speed first, at which time the condenser fan is turned off. The condenser fan is started and controlled to run at the minimum speed after the compressor's suction and discharge pressure difference is established. After the condenser fan has been running for a certain period of time, the refrigerant pump starts at the lowest speed until the refrigerant pump establishes a certain head and then the compressor is turned off.

[0136] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0137] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0138] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0139] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0140] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0141] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

[0142] In any one or more of the exemplary embodiments described above, the described functionality may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functionality may be stored as one or more instructions or code on or transmitted via a computer-readable medium and executed by a hardware-based processing unit. The computer-readable medium may comprise a computer-readable storage medium corresponding to a tangible medium such as a data storage medium, or a communication medium comprising any medium facilitating the transfer of a computer program from one place to another, for example, according to a communication protocol. In this manner, a computer-readable medium may generally correspond to a non-transitory tangible computer-readable storage medium or a communication medium such as a signal or carrier wave. The data storage medium may be any available medium accessible by one or more computers or one or more processors to retrieve instructions, code, and / or data structures for implementing the techniques described in this disclosure. Computer program products may comprise computer-readable media.

[0143] For example, and not as a limitation, such computer-readable storage media may include RAM, ROM, EEPROM, CD-ROM or other optical disc storage devices, magnetic disk storage devices or other magnetic storage devices, flash memory, or any other medium that can be used to store desired program code in the form of instructions or data structures and is accessible by a computer. Furthermore, 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 media, but rather refer to non-transient tangible storage media. As used herein, disks and optical discs include compact optical discs (CDs), laser discs, optical discs, digital versatile discs (DVDs), floppy disks, or Blu-ray discs, where disks typically reproduce data magnetically, while optical discs use lasers to reproduce data optically. The above combinations should also be included within the scope of computer-readable media.

[0144] For example, instructions can 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. Therefore, the term "processor" as used herein can refer to any of the above-described structures or any other structures suitable for implementing the techniques described herein. Additionally, in some aspects, the functionality described herein can be provided within dedicated hardware and / or software modules configured for encoding and decoding, or incorporated into combined codecs. Furthermore, the techniques can be fully implemented in one or more circuit or logic elements.

[0145] The technical solutions of the embodiments of this disclosure can be implemented in a wide variety of devices or equipment, including wireless mobile phones, integrated circuits (ICs), or a set of ICs (e.g., chipsets). Various components, modules, or units are described in the embodiments of this disclosure to emphasize functional aspects of a device configured to perform the described techniques, but they do not necessarily need to be implemented through different hardware units. Rather, as described above, the various units can be combined in codec hardware units or provided by a collection of interoperable hardware units (including one or more processors as described above) combined with suitable software and / or firmware.

Claims

1. A method for starting a refrigerant pump for a dual-cycle refrigeration system, characterized in that, The dual-cycle refrigeration system includes a compressor, a refrigerant pump, and a condenser fan; the dual-cycle refrigeration system has a compressor refrigeration mode and a refrigerant pump refrigeration mode, in which the compressor and the refrigerant pump respectively provide power for the system's refrigeration operation; The fluorine pump start-up method includes: The conditions for starting the refrigerant pump with the compressor auxiliary have been met; The fluorine pump is started with the assistance of a compressor; The step of starting the refrigerant pump with the assistance of the compressor includes: starting the compressor; starting the refrigerant pump after the compressor meets a first set operating condition, so that the refrigerant pump runs together with the compressor; and shutting down the compressor based on the refrigerant pump meeting a second set operating condition. Before starting the refrigerant pump and making it run together with the compressor, the refrigerant pump starting method further includes: controlling the speed of the condenser fan; and, based on the establishment of a third set operating condition, performing the step of starting the refrigerant pump and making it run together with the compressor. The compressor meeting the first set operating condition indicates that the compressor has been successfully started and the suction and discharge pressure difference has been established; the refrigerant pump meeting the second set operating condition indicates that the refrigerant pump has been successfully started and is operating stably; and the third set operating condition being met indicates that the operation of the condenser fan will not affect the start-up of the refrigerant pump.

2. The fluorine pump starting method according to claim 1, characterized in that, The first set operating conditions include at least one of the following: The difference between the compressor's discharge pressure and suction pressure reaches the set pressure difference range. The compressor runs for a period of time that reaches a first set time range.

3. The fluorine pump starting method according to claim 1, characterized in that, The second set operating conditions include at least one of the following: The head of the fluorine pump reaches the set head range; The fluorine pump operates for a duration that reaches the second set time range.

4. The method for starting a fluorine pump according to any one of claims 1 to 3, characterized in that, The control of the condenser fan speed includes: Before the compressor meets the first set operating conditions, the speed of the condenser fan is controlled to the first set speed; Based on the compressor meeting the first set operating conditions, the speed of the condenser fan is controlled to a second set speed, which is higher than the first set speed.

5. The fluorine pump starting method according to claim 4, characterized in that, The third set operating condition includes: the duration of operation of the condenser fan at the second set speed reaches the third set duration range.

6. The method for starting a fluorine pump according to any one of claims 1 to 3, characterized in that, In the step of starting the compressor, the compressor is controlled to start at a third set speed; and / or In the step of starting the fluorine pump, the fluorine pump is controlled to start at a fourth set speed.

7. The method for starting a fluorine pump according to any one of claims 1 to 3, characterized in that, The conditions for compressor-assisted start-up of the refrigerant pump include at least one of the following: The outdoor ambient temperature is within the set temperature range; The fluorine pump failed to start automatically.

8. A control device, characterized in that, It includes a processor and a memory storing a computer program, wherein the processor executes the computer program to implement the steps of the fluorine pump start-up method as described in any one of claims 1 to 7.

9. A dual-cycle refrigeration system, characterized in that, Includes the control device as described in claim 8.

10. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the fluorine pump start-up method as described in any one of claims 1 to 7.

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