Refrigerant leakage early warning method and terminal of heat pump unit

Abstract

The application discloses a refrigerant leakage early warning method and a terminal of a heat pump unit. Since the compressor is in a working state when the heat pump unit is in refrigeration and heating, the operation mode of the heat pump unit is received, the target temperature of the heat pump unit is determined according to the operation mode, if the difference between the liquid supply temperature of the water pump in the heat pump unit and the target temperature is greater than a temperature threshold value, the heat pump unit is early warned, and if the difference between the pressure rated value of the compressor in the heat pump unit and the condensing pressure is greater than a pressure threshold value, the heat pump unit is early warned. In this way, the refrigerant leakage state of the compressor is judged through the water temperature change of the water pump and the refrigerant pressure change of the compressor, refrigerant leakage can be early warned, and the problem of over-temperature of the battery system caused by refrigerant leakage can be prevented.

Description

Technical Field

[0001] This invention relates to the technical field of early warning for new energy storage, and in particular to a method and terminal for early warning of refrigerant leakage in heat pump units. Background Technology

[0002] In the field of new energy storage, as the capacity of energy storage containers gradually expands and the demands of operating conditions increase, the thermal management of lithium batteries used in energy storage continues to favor liquid cooling, and the development of high-power output water-cooled energy storage units is receiving increasing attention. To maintain a suitable charging and discharging temperature range for the batteries, the unit provides continuous cooling and heating to the battery pack thermal management system, while also needing to provide corresponding cooling and heating power consumption.

[0003] Currently, users in the industrial and commercial energy storage sector primarily focus on two main areas: the lifespan of the energy storage system and its corresponding cycle count, and the energy consumption of the energy storage system during operation. The latter stems from energy losses in the electrical system and primarily from energy losses in the thermal management system. With energy conservation and increased production as the main development goals, the future direction of the energy storage field is to achieve these goals.

[0004] For the unit, conventional thermal management energy consumption comes from key components such as compressors, PTC electric heaters, and water pumps in both cooling and heating modes. In low-temperature winter conditions, to maintain the appropriate temperature range for normal battery charging and discharging and storage, taking a liquid-cooled container as an example, the vast majority of thermal management energy consumption is used to ensure the heating water temperature for water circulation. However, while PTC electric heating is currently the primary heating method, its energy efficiency ratio is far lower than that of heat pump heating.

[0005] Compared to cooling-only units, heat pump units operate with the compressor running during both cooling and heating, placing higher demands on the pressure resistance of the refrigerant system piping. Furthermore, under prolonged high-pressure and high-temperature operation, there is a risk of refrigerant leakage, which can lead to overheating of the battery system and compromise system safety. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a refrigerant leakage early warning method and terminal for heat pump units, which can provide early warning processing for refrigerant leakage and prevent the battery system from overheating due to refrigerant leakage.

[0007] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0008] A method for early warning of refrigerant leakage in a heat pump unit includes the following steps:

[0009] Receive the operating mode of the heat pump unit and determine the target temperature of the heat pump unit based on the operating mode;

[0010] The liquid supply temperature of the water pump in the heat pump unit is obtained. If the difference between the liquid supply temperature and the target temperature is greater than the temperature threshold, an early warning is issued for the heat pump unit.

[0011] The condensing pressure of the compressor in the heat pump unit is obtained. If the difference between the rated pressure and the condensing pressure is greater than the pressure threshold, an early warning is issued for the heat pump unit.

[0012] To solve the above-mentioned technical problems, another technical solution adopted by the present invention is as follows:

[0013] A refrigerant leak early warning terminal for a heat pump unit includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it performs the following steps:

[0014] Receive the operating mode of the heat pump unit and determine the target temperature of the heat pump unit based on the operating mode;

[0015] The liquid supply temperature of the water pump in the heat pump unit is obtained. If the difference between the liquid supply temperature and the target temperature is greater than the temperature threshold, an early warning is issued for the heat pump unit.

[0016] The condensing pressure of the compressor in the heat pump unit is obtained. If the difference between the rated pressure and the condensing pressure is greater than the pressure threshold, an early warning is issued for the heat pump unit.

[0017] The beneficial effects of this invention are as follows: Since the compressor of the heat pump unit is in operation during both cooling and heating, the operating mode of the heat pump unit is received, and the target temperature of the heat pump unit is determined according to the operating mode. If the difference between the liquid supply temperature of the water pump in the heat pump unit and the target temperature is greater than the temperature threshold, an early warning is issued for the heat pump unit; if the difference between the rated pressure of the compressor in the heat pump unit and the condensing pressure is greater than the pressure threshold, an early warning is issued for the heat pump unit. In this way, by judging the refrigerant leakage status of the compressor through the changes in water temperature of the water pump and the changes in refrigerant pressure of the compressor, an early warning and handling of refrigerant leakage can be carried out to prevent the battery system from overheating due to refrigerant leakage. Attached Figure Description

[0018] Figure 1 This is a flowchart of a refrigerant leakage early warning method for a heat pump unit according to an embodiment of the present invention;

[0019] Figure 2 This is a schematic diagram of a refrigerant leakage early warning terminal for a heat pump unit according to an embodiment of the present invention;

[0020] Figure 3 This is a flowchart illustrating the specific steps of a refrigerant leakage early warning method for a heat pump unit according to an embodiment of the present invention.

[0021] Figure 4 This is a structural diagram of a heat pump unit according to an embodiment of the present invention.

[0022] Label Explanation:

[0023] 1. A refrigerant leakage early warning terminal for a heat pump unit; 2. A memory; 3. A processor. Detailed Implementation

[0024] To explain in detail the technical content, objectives, and effects of the present invention, the following description is provided in conjunction with the embodiments and accompanying drawings.

[0025] Please refer to Figure 1 This invention provides a refrigerant leakage early warning method for heat pump units, including the following steps:

[0026] Receive the operating mode of the heat pump unit and determine the target temperature of the heat pump unit based on the operating mode;

[0027] The liquid supply temperature of the water pump in the heat pump unit is obtained. If the difference between the liquid supply temperature and the target temperature is greater than the temperature threshold, an early warning is issued for the heat pump unit.

[0028] The condensing pressure of the compressor in the heat pump unit is obtained. If the difference between the rated pressure and the condensing pressure is greater than the pressure threshold, an early warning is issued for the heat pump unit.

[0029] As described above, the beneficial effects of this invention are as follows: Since the compressor of the heat pump unit is in operation during both cooling and heating, the operating mode of the heat pump unit is received, and the target temperature of the heat pump unit is determined according to the operating mode. If the difference between the liquid supply temperature of the water pump in the heat pump unit and the target temperature is greater than the temperature threshold, an early warning is issued for the heat pump unit; if the difference between the rated pressure of the compressor in the heat pump unit and the condensing pressure is greater than the pressure threshold, an early warning is issued for the heat pump unit. In this way, by judging the refrigerant leakage status of the compressor through the changes in water temperature of the water pump and the changes in refrigerant pressure of the compressor, an early warning and handling of refrigerant leakage can be carried out, preventing the battery system from overheating due to refrigerant leakage.

[0030] Furthermore, if the difference between the supply liquid temperature and the target temperature is greater than a temperature threshold, an early warning is issued for the heat pump unit, including:

[0031] If the difference between the supply temperature and the target temperature is greater than the first temperature threshold and less than or equal to the second temperature threshold within a preset time, the heat pump unit will be given a first-level warning.

[0032] If the difference between the supply temperature and the target temperature is greater than the second temperature threshold within a preset time, a second-level warning is issued to the heat pump unit so that the heat pump unit executes a standby command.

[0033] The first temperature threshold is less than the second temperature threshold.

[0034] As described above, the warning level is determined based on the difference between the supply temperature and the target temperature. The first-level warning indicates a slight refrigerant leak, but the operating conditions are still met. The second-level warning indicates a significant refrigerant leak, resulting in a large reduction in the cooling capacity of the heat pump unit. The heat pump unit needs to execute a standby command, and the refrigerant leak is judged by the water temperature output by the water pump.

[0035] Furthermore, if the difference between the supply liquid temperature and the target temperature is greater than a temperature threshold, an early warning is issued for the heat pump unit, which also includes:

[0036] Determine whether the liquid supply temperature is greater than a third temperature threshold within a preset time. If so, cut off the power supply to the heat pump unit.

[0037] As described above, when the liquid supply temperature is greater than the third temperature threshold for a continuous period of time, it indicates that the heating temperature has exceeded the operating range of the heat pump unit. The battery system overheating can be prevented by cutting off the power supply.

[0038] Furthermore, if the difference between the rated pressure and the condensing pressure is greater than the pressure threshold, an early warning is issued for the heat pump unit, including:

[0039] If the difference between the rated pressure and the condensing pressure is greater than the first pressure threshold and less than or equal to the second pressure threshold within a preset time, the heat pump unit will be given a first-level warning.

[0040] If the difference between the rated pressure and the condensing pressure is greater than the second pressure threshold within a preset time, a second-level warning will be issued to the heat pump unit so that the heat pump unit will execute a standby command.

[0041] The first pressure threshold is less than the second pressure threshold.

[0042] As described above, the warning level is determined based on the difference between the rated pressure and the condensing pressure. The first-level warning indicates a slight refrigerant leak, but the operating conditions are still met. The second-level warning indicates a significant refrigerant leak, resulting in a large reduction in the cooling capacity of the heat pump unit, requiring the heat pump unit to execute a standby command. The refrigerant leak is determined by the compressor pressure in this way.

[0043] Furthermore, if the difference between the rated pressure and the condensing pressure is greater than the pressure threshold, an early warning is issued for the heat pump unit, which also includes:

[0044] Determine whether the difference between the rated pressure and the condensing pressure within a preset time period is greater than a third pressure threshold. If so, cut off the power supply to the heat pump unit.

[0045] As described above, if the difference between the rated pressure and the condensing pressure is greater than the third pressure threshold for a continuous period of time, it indicates that the condensing capacity of the heat pump unit has been reduced, and the battery system should be prevented from overheating by cutting off the power supply.

[0046] Please refer to Figure 2 Another embodiment of the present invention provides a refrigerant leakage early warning terminal for a heat pump unit, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the various steps of the above-described refrigerant leakage early warning method for a heat pump unit.

[0047] The refrigerant leakage early warning method and terminal of the present invention are applicable to refrigerant leakage early warning of heat pump water-cooled units. By analyzing changes in water pump temperature and refrigerant pressure in the compressor, the refrigerant leakage status of the compressor is determined, enabling early warning and handling of refrigerant leakage to prevent overheating of the battery system due to refrigerant leakage. The following detailed embodiments illustrate this method:

[0048] Example 1

[0049] Please refer to Figure 1 and Figure 3 A method for early warning of refrigerant leakage in a heat pump unit, comprising the following steps:

[0050] S1. Receive the operating mode of the heat pump unit and determine the target temperature of the heat pump unit based on the operating mode.

[0051] In this embodiment, data from the heat pump water-cooled unit is collected, and the operating mode of the heat pump unit is received. The operating mode is divided into cooling mode or heating mode, and the target temperature of the heat pump unit can be determined according to the operating mode.

[0052] Please refer to Figure 4In this embodiment, the heat pump unit uses a four-way reversing valve 2 to control the flow of coolant in the heat exchange circuit. In cooling mode, the coolant is compressed into a high-temperature, high-pressure gaseous state by the compressor 1, then condenses in the outdoor heat exchanger 3, and flows to the plate heat exchanger 6 to exchange heat with water flowing out of the expansion tank 7. The cooled water is then pumped by the water pump 8 through the water circulation loop to the battery cluster to absorb heat and cool it down. The high-temperature coolant then flows back into the compressor 1 through the four-way reversing valve 2 to restart the next compression, condensation, and evaporation heat absorption cooling cycle. In heating mode, the high-temperature, high-pressure coolant gas compressed by the compressor 1 can first flow into the plate heat exchanger 6 through the four-way reversing valve 2 for condensation and heat release before flowing into the expansion tank 7. After the water is heated, the hot water can be used to heat the battery clusters through the water circulation loop. The low-temperature coolant after heat exchange and condensation continues to evaporate and absorb heat through the outdoor heat exchanger 3, and then flows back into the compressor 1 through the four-way reversing valve 2 to restart the next heating cycle of compression, condensation, heat release, and evaporation. At the same time, by adding a natural cooling coil 5, in the cooling process under low temperature environment, the natural cooling coil 5, water pump 8 and expansion tank 7 directly form a natural water cooling loop. The water in the expansion tank 7 can be directly sent to the natural cooling coil 5 through the natural water cooling loop to cool down with the low temperature environment outside, and then sent into the battery clusters by the water pump 8 to absorb heat and cool down the battery clusters. That is, at 0℃, heat can be exchanged through the fan 4, and at this time, the compressor 1 does not need to be started.

[0053] S2. Obtain the liquid supply temperature of the water pump in the heat pump unit. If the difference between the liquid supply temperature and the target temperature is greater than the temperature threshold, issue an early warning to the heat pump unit.

[0054] S21. If the difference between the supply temperature and the target temperature is greater than the first temperature threshold and less than or equal to the second temperature threshold within a preset time, then a first-level warning is issued to the heat pump unit.

[0055] Wherein, the first temperature threshold is less than the second temperature threshold. In this embodiment, the first temperature threshold is 3°C and the second temperature threshold is 8°C.

[0056] If the difference between the water pump's supply temperature and the target temperature is greater than 3°C and less than or equal to 8°C within 10 minutes, a first-level warning will be issued for the heat pump unit. At this time, there is a slight refrigerant leak, but the operating conditions are still met.

[0057] S22. If the difference between the supply temperature and the target temperature is greater than the second temperature threshold within a preset time, a second-level warning is issued to the heat pump unit so that the heat pump unit executes a standby command.

[0058] If the difference between the water pump's supply temperature and the target temperature exceeds 8°C within 10 minutes, a second-level warning will be issued for the heat pump unit, and the heat pump unit will execute a standby command.

[0059] After the heat pump unit executes the standby command, it can upload temperature data to the energy management system, at which point the energy management system is powered off. Since the data stored in the energy management system can be used for subsequent analysis, the power outage here is due to the unclear cause of the refrigerant leak. If the refrigerant leak is caused by a problem with the compressor itself, then powering off the system is beneficial for protecting the equipment.

[0060] S23. Determine whether the liquid supply temperature is greater than the third temperature threshold within a preset time. If so, cut off the power supply to the heat pump unit.

[0061] In this embodiment, the third temperature threshold is 50°C. Specifically, if the liquid supply temperature exceeds 50°C within 10 minutes, it indicates that the water temperature exceeds the battery's operating range, and the power supply to the heat pump unit needs to be cut off.

[0062] S3. Obtain the condensing pressure of the compressor in the heat pump unit. If the difference between the rated pressure and the condensing pressure is greater than the pressure threshold, issue an early warning for the heat pump unit.

[0063] In some embodiments, it can be first determined whether the unit is in standby mode. If so, the condensing pressure of the compressor can be used to determine whether to issue an early warning to the heat pump unit.

[0064] S31. If the difference between the rated pressure and the condensing pressure is greater than the first pressure threshold and less than or equal to the second pressure threshold within a preset time, a first-level warning is issued for the heat pump unit.

[0065] Wherein, the first pressure threshold is less than the second pressure threshold. In this embodiment, the first pressure threshold is 3 bar and the second pressure threshold is 10 bar. The pressure rating can be taken from 30 to 40 bar.

[0066] If the difference between the compressor's rated pressure and the condensing pressure is greater than 3 bar and less than or equal to 10 bar within 10 minutes, a first-level warning will be issued for the heat pump unit. At this time, there is a slight refrigerant leak, but the operating conditions are still met.

[0067] S32. If the difference between the rated pressure and the condensing pressure is greater than the second pressure threshold within a preset time, a second-level warning is issued to the heat pump unit so that the heat pump unit executes a standby command.

[0068] If the difference between the compressor's rated pressure and the condensing pressure is greater than 10 bar and less than or equal to 15 bar within 10 minutes, a second-level warning will be issued for the heat pump unit, and the heat pump unit will execute a standby command.

[0069] After the heat pump unit executes the standby command, it can upload the pressure data to the energy management system, and then the energy management system will be powered off.

[0070] S33. Determine whether the difference between the rated pressure and the condensing pressure within a preset time is greater than the third pressure threshold. If so, cut off the power supply to the heat pump unit.

[0071] In this embodiment, the third pressure threshold is 15 bar. Specifically, if the difference between the rated pressure and the condensing pressure is greater than 15 bar within 10 minutes, it indicates that the refrigerant leakage is too large and the cooling capacity of the heat pump unit is too reduced, so it is necessary to cut off the power supply to the heat pump unit.

[0072] Example 2

[0073] Please refer to Figure 2 A refrigerant leakage early warning terminal 1 for a heat pump unit includes a memory 2, a processor 3, and a computer program stored in the memory 2 and executable on the processor 3. When the processor 3 executes the computer program, it implements the various steps of the refrigerant leakage early warning method for a heat pump unit according to Embodiment 1.

[0074] In summary, the refrigerant leakage early warning method and terminal provided by this invention for heat pump units, since the compressor of the heat pump unit is in operation during both cooling and heating, receives the operating mode of the heat pump unit, determines the target temperature of the heat pump unit based on the operating mode, and issues an early warning if the difference between the liquid supply temperature of the water pump in the heat pump unit and the target temperature is greater than a temperature threshold; similarly, it issues an early warning if the difference between the rated pressure of the compressor in the heat pump unit and the condensing pressure is greater than a pressure threshold. In this way, by judging the refrigerant leakage status of the compressor through changes in water pump temperature and refrigerant pressure of the compressor, early warning processing of refrigerant leakage can be carried out, preventing battery system overheating problems caused by refrigerant leakage.

[0075] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent modifications made based on the content of the present invention specification and drawings, or direct or indirect applications in related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A method for early warning of refrigerant leakage in a heat pump unit, characterized in that, Including the following steps: By controlling the four-way reversing valve, the flow direction of the coolant in the heat exchange circuit is switched to match the operating mode of the heat pump unit; Receive the operating mode of the heat pump unit and determine the target temperature of the heat pump unit based on the operating mode; The system obtains the liquid supply temperature of the water pump in the heat pump unit. If the difference between the liquid supply temperature and the target temperature is greater than a temperature threshold, an early warning is issued to the heat pump unit. This includes: if the difference between the liquid supply temperature and the target temperature is greater than a first temperature threshold and less than or equal to a second temperature threshold within a preset time, a first-level early warning is issued to the heat pump unit; if the difference between the liquid supply temperature and the target temperature is greater than the second temperature threshold within a preset time, a second-level early warning is issued to the heat pump unit, causing the heat pump unit to execute a standby command; the first temperature threshold is less than the second temperature threshold; and it is determined whether the liquid supply temperature is greater than a third temperature threshold within a preset time. If so, the power supply to the heat pump unit is cut off. The condensing pressure of the compressor in the heat pump unit is obtained. If the difference between the rated pressure and the condensing pressure is greater than the pressure threshold, an early warning is issued for the heat pump unit.

2. The refrigerant leakage early warning method for a heat pump unit according to claim 1, characterized in that, If the difference between the rated pressure and the condensing pressure is greater than the pressure threshold, an early warning will be issued for the heat pump unit, including: If the difference between the rated pressure and the condensing pressure is greater than the first pressure threshold and less than or equal to the second pressure threshold within a preset time, the heat pump unit will be given a first-level warning. If the difference between the rated pressure and the condensing pressure is greater than the second pressure threshold within a preset time, a second-level warning will be issued to the heat pump unit so that the heat pump unit will execute a standby command. The first pressure threshold is less than the second pressure threshold.

3. The refrigerant leakage early warning method for a heat pump unit according to claim 1, characterized in that, If the difference between the rated pressure and the condensing pressure is greater than the pressure threshold, an early warning is issued for the heat pump unit, which also includes: Determine whether the difference between the rated pressure and the condensing pressure within a preset time period is greater than a third pressure threshold. If so, cut off the power supply to the heat pump unit.

4. A refrigerant leak early warning terminal for a heat pump unit, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it performs the following steps: By controlling the four-way reversing valve, the flow direction of the coolant in the heat exchange circuit is switched to match the operating mode of the heat pump unit; Receive the operating mode of the heat pump unit and determine the target temperature of the heat pump unit based on the operating mode; The system obtains the liquid supply temperature of the water pump in the heat pump unit. If the difference between the liquid supply temperature and the target temperature is greater than a temperature threshold, an early warning is issued to the heat pump unit. This includes: if the difference between the liquid supply temperature and the target temperature is greater than a first temperature threshold and less than or equal to a second temperature threshold within a preset time, a first-level early warning is issued to the heat pump unit; if the difference between the liquid supply temperature and the target temperature is greater than the second temperature threshold within a preset time, a second-level early warning is issued to the heat pump unit, causing the heat pump unit to execute a standby command; the first temperature threshold is less than the second temperature threshold; and it is determined whether the liquid supply temperature is greater than a third temperature threshold within a preset time. If so, the power supply to the heat pump unit is cut off. The condensing pressure of the compressor in the heat pump unit is obtained. If the difference between the rated pressure and the condensing pressure is greater than the pressure threshold, an early warning is issued for the heat pump unit.

5. A refrigerant leakage early warning terminal for a heat pump unit according to claim 4, characterized in that, If the difference between the rated pressure and the condensing pressure is greater than the pressure threshold, an early warning will be issued for the heat pump unit, including: If the difference between the rated pressure and the condensing pressure is greater than the first pressure threshold and less than or equal to the second pressure threshold within a preset time, the heat pump unit will be given a first-level warning. If the difference between the rated pressure and the condensing pressure is greater than the second pressure threshold within a preset time, a second-level warning will be issued to the heat pump unit so that the heat pump unit will execute a standby command. The first pressure threshold is less than the second pressure threshold.

6. A refrigerant leakage early warning terminal for a heat pump unit according to claim 4, characterized in that, If the difference between the rated pressure and the condensing pressure is greater than the pressure threshold, an early warning is issued for the heat pump unit, which also includes: Determine whether the difference between the rated pressure and the condensing pressure within a preset time period is greater than a third pressure threshold. If so, cut off the power supply to the heat pump unit.

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