A defrosting control method, control device and heat exchange equipment
By optimizing the defrosting control method of the heat exchange equipment and dynamically adjusting the defrosting end time based on the defrosting stage parameter information, the problems of incomplete defrosting or excessively long defrosting time were solved, thus improving the equipment operating efficiency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- HEFEI MIDEA HEATING & VENTILATING EQUIP
- Filing Date
- 2022-09-09
- Publication Date
- 2026-07-21
AI Technical Summary
In existing heat exchange equipment, the fixed defrosting time or temperature setting during the defrosting process leads to incomplete defrosting or excessively long defrosting time, affecting operating efficiency.
By optimizing the defrosting control method, the target coil temperature for ending the defrosting mode is determined based on the defrosting stage parameter information of the heat exchanger, the fixed uniform conditions are eliminated, and the defrosting end time is dynamically adjusted.
It improves the operating efficiency of heat exchange equipment, avoids incomplete defrosting or excessively long defrosting time, and optimizes the defrosting process.
Smart Images
Figure CN116147244B_ABST
Abstract
Description
Technical Field
[0001] This application relates to, but is not limited to, the field of heat exchange equipment technology, specifically to a defrosting control method, control device, and heat exchange equipment. Background Technology
[0002] Currently, in heat exchange equipment such as air-source heat pump units, water vapor in the air condenses into frost on the surface of the air-side heat exchanger during heating operation, leading to a reduction in heat exchange efficiency. This necessitates entering defrost mode to defrost the air-side heat exchanger. Currently, the common method is to exit defrost mode when a fixed defrosting time is reached or when the air-side heat exchanger tube temperature reaches a preset temperature. This method has the following problems: Due to varying degrees of frost buildup, using the above method to exit defrost mode may result in incomplete defrosting or excessively long defrosting time, which may also affect the operating efficiency of the heat exchange equipment. Summary of the Invention
[0003] The technical problem to be solved by this application is to provide a defrosting control method that can improve the phenomenon of incomplete defrosting or excessively long defrosting time.
[0004] This application provides a defrosting control method for a heat exchange device. The heat exchange device includes a compressor, a reversing valve, a first heat exchanger, a throttling device, and a second heat exchanger connected by refrigerant pipelines. The first heat exchanger is a first heat exchanger that needs to be defrosted. The defrosting control method includes: defrosting the first heat exchanger in a defrosting mode; determining a target coil temperature to end the defrosting mode, the target coil temperature being determined at least based on defrosting stage parameter information of the first heat exchanger; and exiting the defrosting mode based on the coil temperature of the first heat exchanger rising to be greater than or equal to the target coil temperature.
[0005] The defrosting control method provided in this application optimizes and improves the criteria for determining the end of the defrosting mode. It eliminates the fixed and uniform conditions in traditional methods, instead determining the target coil temperature for ending the defrosting mode based at least on the defrosting stage information of the first heat exchanger. Since the defrosting stage parameters of the first heat exchanger are related to the degree of frost formation, and these parameters qualitatively reflect the degree of frost formation, the target coil temperature determined based at least on these parameters can change with the degree of frost formation. This allows the target coil temperature to match the degree of frost formation on the first heat exchanger, facilitating the timely exit of the defrosting mode from the heat exchange equipment. This improves upon the incomplete defrosting or excessively long defrosting time caused by traditional methods, thereby enhancing the operating efficiency of the heat exchange equipment.
[0006] Based on the above technical solution, the following improvements can be made to this application.
[0007] In an exemplary embodiment, the defrosting stage of the first heat exchanger includes an initial heating stage, a mid-term constant temperature stage, and a final heating stage; the defrosting control method further includes: determining that the first heat exchanger is in the initial heating stage based on the coil temperature of the first heat exchanger being less than 0°C; determining that the first heat exchanger is in the mid-term constant temperature stage based on the coil temperature of the first heat exchanger being greater than or equal to 0°C and less than or equal to D; and determining that the first heat exchanger is in the final heating stage based on the coil temperature of the first heat exchanger being greater than D.
[0008] In one exemplary embodiment, the defrosting stage parameter information includes: the duration of the intermediate isothermal stage; and the target coil temperature is positively correlated with the duration of the intermediate isothermal stage.
[0009] In one exemplary embodiment, the target coil temperature is determined based on the duration of the intermediate isothermal phase and the ambient relative humidity of the previous heating cycle; the target coil temperature is also positively correlated with the ambient relative humidity of the previous heating cycle.
[0010] In an exemplary embodiment, determining the target coil temperature based on the duration of the intermediate constant temperature phase and the ambient relative humidity of the previous heating cycle includes: calculating the target coil temperature according to the following formula: Tquit=a×t+b; where Tquit is the target coil temperature, a is the ambient relative humidity of the previous heating cycle, t is the duration of the intermediate constant temperature phase, and b is the compensation value of the coil temperature sensor.
[0011] In an exemplary embodiment, the ambient relative humidity of the previous heating cycle is determined by the following method: during the previous heating cycle, the ambient relative humidity is detected and recorded at first set intervals; the average value of all ambient relative humidity recorded in the previous heating cycle is calculated to obtain the ambient relative humidity of the previous heating cycle.
[0012] In one exemplary embodiment, the defrosting stage parameter information includes: the coil heating rate during the final heating stage; and the target coil temperature is negatively correlated with the coil heating rate during the final heating stage.
[0013] In an exemplary embodiment, determining the target coil temperature based on the coil temperature rise rate during the final heating stage includes: calculating the target coil temperature according to the following formula: Tquit=Ts / ∑k+b; where Tquit is the target coil temperature updated periodically, Ts is the set temperature, ∑k is the cumulative value of the coil temperature rise rate during the final heating stage updated periodically, and b is the compensation value of the coil temperature sensor.
[0014] In an exemplary embodiment, the cumulative value of the tube temperature rise rate in the timed-updated final heating stage is determined by the following method: based on the determination that the first heat exchanger has entered the final heating stage, the coil temperature of the first heat exchanger is acquired at second set intervals, and the coil heating rate k of the first heat exchanger within the second set interval is calculated; the sum of all coil heating rates k calculated in the same final heating stage is calculated to obtain the cumulative value ∑k of the tube temperature rise rate in the timed-updated final heating stage.
[0015] In one exemplary embodiment, the Ts is in the range of 10°C to 15°C.
[0016] In one exemplary embodiment, b is in the range of 5°C to 10°C.
[0017] In one exemplary embodiment, D is in the range of 1°C to 3°C.
[0018] 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 defrosting control method as described in any of the above embodiments.
[0019] This application also provides a heat exchange device, including the control device described in the above embodiments. Attached Figure Description
[0020] Figure 1 A schematic flowchart of a defrosting control method provided in one embodiment of this application; Figure 2 A schematic flowchart of a defrosting control method provided in a specific embodiment of this application; Figure 3 A schematic flowchart of a defrosting control method provided in another specific embodiment of this application; Figure 4 A schematic block diagram of a control device provided in one embodiment of this application; Figure 5 This is a schematic diagram of the structure of an air source heat pump unit provided in one embodiment of this application.
[0021] The attached diagram lists the components represented by each number as follows: 402 processor, 404 controller; 502 Compressor, 504 Four-way reversing valve, 506 Water-side heat exchanger, 508 Electronic expansion valve, 510 Air-side heat exchanger, 512 Gas-liquid separator, 514 Pipe temperature sensor, 516 Ambient humidity sensor, 518 Ambient temperature sensor. Detailed Implementation
[0022] 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.
[0023] In this embodiment, the heat exchange equipment can be an air source heat pump unit, or a regular household air conditioner, central air conditioning, etc. The air source heat pump unit can be an air source heat pump air conditioner, or an air source heat pump water heater, etc. Typically, the outdoor heat exchanger is a heat exchanger that requires defrosting.
[0024] The following section uses an air source heat pump unit as an example to introduce the heating operation principle and defrosting principle of heat exchange equipment.
[0025] like Figure 5 As shown, the air source heat pump unit includes a compressor 502, a four-way reversing valve 504, a water-side heat exchanger 506, an electronic expansion valve 508, an air-side heat exchanger 510, a gas-liquid separator 512, and a pipe temperature sensor 514 located at the inlet of the air-side heat exchanger 510. In some examples, the air source heat pump unit may also include an ambient humidity sensor 516 and an ambient temperature sensor 518. The air-side heat exchanger 510 is a heat exchanger that requires defrosting.
[0026] Heating operation: The refrigerant is compressed into a high-temperature and high-pressure superheated gas by the compressor 502, passes through port D to port C of the four-way reversing valve 504, and condenses into a normal-temperature and high-pressure subcooled liquid in the water-side heat exchanger 506 (while heating the flowing water). It is then throttled by the electronic expansion valve 508 into a low-temperature and low-pressure gas-liquid two-phase mixture, flows into the air-side heat exchanger 510 to evaporate and absorb heat, passes through port E to port S of the four-way reversing valve 504, and finally returns to the compressor 502 after passing through the gas-liquid separator 512.
[0027] Defrosting Operation: The refrigerant is compressed into a high-temperature, high-pressure superheated gas by compressor 502. This high-temperature, high-pressure refrigerant, passing through ports D and E of the four-way reversing valve 504, heats the air-side heat exchanger 510. The frost on the air-side heat exchanger 510 melts into water after heating, which is collected in the water collection tank and discharged. The water is then throttled by electronic expansion valve 508 into a low-temperature, low-pressure gas-liquid two-phase mixture, flowing into the water-side heat exchanger 506 for evaporation and heat absorption. After passing through ports C and S of the four-way reversing valve 504, it finally returns to compressor 502 after passing through gas-liquid separator 512. Pipe temperature sensor 514 is located at the inlet of air-side heat exchanger 510 during heating operation (and at the outlet of air-side heat exchanger 510 during defrosting operation).
[0028] In other words, during heating operation, the air-side heat exchanger 510 acts as an evaporator, absorbing heat from the environment; the other heat exchanger (water-side heat exchanger 506) acts as a condenser, releasing heat to achieve heat exchange. During defrosting operation, the air-side heat exchanger 510 acts as a condenser, releasing heat to melt frost; the other heat exchanger (water-side heat exchanger 506) acts as an evaporator.
[0029] Currently, the criteria for exiting defrost mode are typically: reaching a fixed defrost time or the air-side heat exchanger 510 tube temperature reaching a preset temperature. However, differences in ambient temperature and humidity can lead to varying degrees of frost formation. Using the aforementioned fixed criteria may result in incomplete defrosting or excessively long defrost times, affecting the operating efficiency of the heat exchange equipment.
[0030] For example, in low ambient temperature and high humidity conditions, the frost layer is thick. If the defrosting time is insufficient and the defrosting mode is exited prematurely, the frost may not be completely melted or the defrosting water may not be discharged in time and may freeze. Conversely, in low ambient temperature and low humidity conditions, the frost layer is thin or there is no frost. There is a phenomenon where defrosting is too fast and the coil temperature detection is delayed. Failure to exit defrosting in time may cause the compressor to trigger the 502 protection against excessively high exhaust temperature or exhaust pressure.
[0031] Based on this, such as Figure 1 As shown in the figure, this application provides a defrosting control method for a heat exchange device. The heat exchange device includes a compressor 502 connected via refrigerant piping, a reversing valve (such as a four-way reversing valve), a first heat exchanger, a throttling device, and a second heat exchanger. The first heat exchanger is the heat exchanger that needs to be defrosted. The first heat exchanger can be an outdoor heat exchanger, and the second heat exchanger can be an indoor heat exchanger.
[0032] Defrosting control methods include: Step S102: In defrost mode, defrost the first heat exchanger; Step S104: Determine the target coil temperature for ending the defrosting mode. The target coil temperature shall be determined based at least on the defrosting stage parameter information of the first heat exchanger. Step S106: Based on the rise of the coil temperature of the first heat exchanger to a level greater than or equal to the target coil temperature, exit the defrosting mode.
[0033] The defrosting control method provided in this application optimizes and improves the criteria for determining the end of the defrosting mode. It eliminates the fixed and uniform conditions in traditional methods, instead determining the target coil temperature for ending the defrosting mode based at least on the defrosting stage information of the first heat exchanger. Since the defrosting stage parameters of the first heat exchanger are related to the degree of frost formation, and these parameters qualitatively reflect the degree of frost formation, the target coil temperature determined based at least on these parameters can change with the degree of frost formation. This allows the target coil temperature to match the degree of frost formation on the first heat exchanger, facilitating the timely exit of the defrosting mode from the heat exchange equipment. This improves upon the incomplete defrosting or excessively long defrosting time caused by traditional methods, thereby enhancing the operating efficiency of the heat exchange equipment.
[0034] In one exemplary embodiment, the defrosting stage of the first heat exchanger includes an initial heating stage, a mid-term isothermal stage, and a final heating stage. The defrosting control method further includes: Based on the fact that the coil temperature of the first heat exchanger is less than 0°C, it is determined that the first heat exchanger is in the initial heating stage. Based on the fact that the coil temperature of the first heat exchanger is greater than or equal to 0℃ and less than or equal to D, the first heat exchanger is determined to be in the intermediate isothermal stage. Based on the fact that the coil temperature of the first heat exchanger is greater than D, it is determined that the first heat exchanger is in the final stage of heating up.
[0035] The defrosting process involves changes occurring on the first heat exchanger, specifically the physical process of ice melting into water. When defrosting mode is entered, the frost on the first heat exchanger is first heated by the high-temperature refrigerant, gradually increasing in temperature until it melts into an ice-water mixture (0°C). During this ice-water mixture stage, the temperature remains at 0°C until the mixture is completely melted into water; the coil temperature of the first heat exchanger can be considered constant. Afterward, the water temperature gradually increases, and as it is collected in the bottom drip tray and drained, the defrosting mode is exited. During this stage, the coil temperature of the first heat exchanger also gradually increases.
[0036] Therefore, the defrosting stage of the first heat exchanger can be divided into three stages: before the ice melts into an ice-water mixture, the coil temperature gradually increases, which is the initial heating stage; during the ice-water mixture stage from the start of melting to complete melting of the ice, the coil temperature can be considered to remain constant, which is the intermediate isothermal stage; and after the ice-water mixture has completely melted into water, the coil temperature continues to rise, which is the final heating stage.
[0037] Since there will be a heat exchange temperature difference D between the coil of the first heat exchanger and the ice-water mixture, the coil temperature will be slightly higher than the temperature of the ice-water mixture. Therefore, the coil temperature of the first heat exchanger during the intermediate isothermal stage is limited to a range greater than or equal to 0℃ and less than or equal to D.
[0038] In one exemplary embodiment, D is in the range of 1°C to 3°C, such as 1°C, 1.5°C, 2°C, 2.5°C, 3°C, etc.
[0039] In this way, the size of D is more appropriate, which helps to ensure that the intermediate constant temperature stage is a mixture of ice and water, thereby improving the rationality of the target coil temperature.
[0040] Of course, D is not limited to the above scope and can be adjusted as needed during actual use.
[0041] In one exemplary embodiment, the defrosting stage parameter information includes the duration of the intermediate isothermal stage. The target coil temperature is positively correlated with the duration of the intermediate isothermal stage. In other words, the longer the intermediate isothermal stage lasts, the higher the target coil temperature; the shorter the intermediate isothermal stage lasts, the lower the target coil temperature.
[0042] During the defrosting process, the residence time of the ice-water mixture on the first heat exchanger can reflect the degree of frost formation. The longer the residence time, the longer the heating time is required for the ice to completely melt into water, thus indicating a more severe degree of frost formation and a thicker frost layer. The shorter the residence time, the shorter the heating time is required for the ice to completely melt into water, thus indicating a lighter degree of frost formation and a thinner frost layer.
[0043] The more severe the frost and the thicker the frost layer, the higher the target coil temperature needs to be to end the defrosting mode. This is to ensure that the frost can be completely melted and the melted water can be drained. It also prevents the water in the first heat exchanger or water tank from freezing at low temperatures if the ice-water mixture is not completely converted into water or the melted water is not drained completely before the defrosting mode is exited in advance.
[0044] The lighter the degree of frost and the thinner the frost layer, the lower the target coil temperature needs to be to end the defrosting mode. This can avoid the risk of the first heat exchanger coil temperature rising rapidly due to failure to exit defrosting in time, and the compressor 502 triggering the exhaust temperature or exhaust pressure protection due to the delay in detection by the coil temperature sensor.
[0045] In one exemplary embodiment, the target coil temperature is determined based on the duration of the intermediate isothermal phase and the ambient relative humidity of the previous heating cycle.
[0046] The target coil temperature is also positively correlated with the ambient relative humidity of the previous heating cycle. In other words, the higher the ambient relative humidity of the previous heating cycle, the higher the target coil temperature; the lower the ambient relative humidity of the previous heating cycle, the lower the target coil temperature.
[0047] The relative humidity of the environment in the previous heating cycle has a direct impact on the degree of frost formation. Generally, the frost layer is thicker under low ambient temperature and high humidity, while the frost layer is thinner or non-existent under low ambient temperature and low humidity. Therefore, the degree of frost formation is positively correlated with the relative humidity of the environment in the previous heating cycle, and thus the target coil temperature is also positively correlated with the relative humidity of the environment in the previous heating cycle, which helps to improve the rationality of the target coil temperature.
[0048] In one exemplary embodiment, determining the target coil temperature based on the duration of the intermediate isothermal phase and the ambient relative humidity of the previous heating cycle includes: The target coil temperature is calculated using the following formula: Tquit = a × t + b.
[0049] Where Tquit is the target coil temperature, a is the ambient relative humidity of the previous heating cycle, t is the duration of the mid-term constant temperature phase, and b is the compensation value of the coil temperature sensor.
[0050] As can be seen from the above formula, the target coil temperature is positively correlated with the ambient relative humidity of the previous heating cycle and the duration of the intermediate constant temperature phase.
[0051] During the defrosting process, timing can begin when the coil temperature Tc of the first heat exchanger starts to meet the criteria for the intermediate isothermal stage (i.e., 0℃≤Tc≤D), and end when Tc no longer meets the criteria for the intermediate isothermal stage (i.e., 0℃≤Tc≤D). The target coil temperature can then be calculated using the formula described above.
[0052] In one example, b is in the range of 5℃ to 10℃, such as 5℃, 6℃, 7℃, 8℃, 9℃, 10℃, etc.
[0053] Of course, b is not limited to the above scope and can be adjusted as needed during actual use.
[0054] In one exemplary embodiment, the ambient relative humidity of the previous heating cycle is determined by the following method: During the previous heating cycle, the ambient relative humidity was detected and recorded at each first set interval. The average value of all ambient relative humidity recorded in the previous heating cycle is calculated to obtain the ambient relative humidity of the previous heating cycle.
[0055] Since the duration of the previous heating cycle can be quite long, and the ambient relative humidity may change over time, using the ambient relative humidity measured at a single moment to characterize the ambient relative humidity of the previous heating cycle may result in significant errors. Therefore, this solution uses the average ambient relative humidity of the previous heating cycle to characterize the ambient relative humidity of the previous heating cycle, resulting in a more accurate and reasonable target coil temperature calculation.
[0056] The specific length of the first set duration is not limited, for example, it can be in the range of 2s to 5s, such as 2s, 3s, 4s, 5s, etc.
[0057] In one exemplary embodiment, the mapping relationship between t and the target coil temperature is stored in memory, and the target coil temperature is determined by looking it up.
[0058] Compared to the aforementioned solutions, this solution can directly determine the target coil temperature by searching, and the electronic control program is simpler.
[0059] In one exemplary embodiment, the defrosting stage parameter information includes: the coil heating rate during the final heating stage; The target coil temperature is negatively correlated with the coil heating rate during the final heating stage. In other words, the higher the coil heating rate during the final heating stage, the lower the target coil temperature; conversely, the lower the coil heating rate during the final heating stage, the higher the target coil temperature.
[0060] During the final heating stage of the first heat exchanger, the coil heating rate can reflect the degree of frost formation. The slower the coil temperature rises, the more severe the frost formation and the thicker the frost layer; the faster the coil temperature rises, the lighter the frost formation and the thinner the frost layer.
[0061] The faster the coil of the first heat exchanger heats up, the lighter the degree of frost and the thinner the frost layer. In this case, the time to exit the defrost mode should be earlier, otherwise the compressor may trigger the 502 exhaust pressure or exhaust temperature protection. The slower the temperature of the coil of the first heat exchanger heats up, the more severe the degree of frost and the thicker the frost layer. In this case, the time to exit the defrost mode should be delayed to ensure that defrosting is clean and that defrosting water can be completely drained.
[0062] Therefore, the coil heating rate during the final heating stage can be used to determine when to exit the defrost mode. Furthermore, the higher the coil heating rate during the final heating stage, the lower the target coil temperature, and the earlier the defrost mode exits; conversely, the lower the coil heating rate during the final heating stage, the higher the target coil temperature, and the later the defrost mode exits.
[0063] In one exemplary embodiment, determining the target coil temperature based on the coil temperature rise rate during the final heating stage includes: The target coil temperature is calculated using the following formula: Tquit = Ts / ∑k + b.
[0064] Where Tquit is the target coil temperature updated periodically, Ts is the set temperature, ∑k is the cumulative value of the coil temperature rise rate in the final heating stage of the periodically updated phase, and b is the compensation value of the coil temperature sensor.
[0065] As the duration of the final heating phase increases, ∑k gradually increases, Tquit gradually decreases, and the coil temperature Tc of the first heat exchanger gradually increases. When Tc ≥ Tquit, the defrosting exit condition is met, and the defrosting mode is exited.
[0066] In one exemplary embodiment, the cumulative value of the tube temperature rise rate during the periodically updated final heating stage is determined by the following method: Based on the determination that the first heat exchanger has entered the final heating stage, the coil temperature of the first heat exchanger is obtained at second set intervals, and the coil heating rate k of the first heat exchanger within the second set interval is calculated. The sum of all coil heating rates k calculated in the same final heating stage is used to obtain the cumulative value ∑k of the coil temperature heating rate in the final heating stage, which is updated periodically.
[0067] The second set duration is not limited, for example, it can be in the range of 2s to 5s, such as 2s, 3s, 4s, 5s, etc.
[0068] During the defrosting process, timing can begin when the coil temperature Tc of the first heat exchanger begins to meet the criteria for the final heating stage (i.e., Tc > D). The coil temperature Tc of the first heat exchanger is periodically detected and acquired, and the heating rate k of the coil within each second set time period is calculated and summed.
[0069] For example: the second set duration is 2s. In the same defrosting cycle, the moment when the coil temperature Tc of the first heat exchanger begins to meet the judgment condition of the final heating stage (i.e., Tc>D) is taken as the moment t=0. Tc is detected and recorded every 2 seconds, and the tube temperature rise rate k within every 2 seconds is calculated. That is: the tube temperature rise rate k(0~2) from 0 seconds to 2 seconds = [Tc(2)-Tc(0)] / 2, the tube temperature rise rate k(2~4) from 2 seconds to 4 seconds = [Tc(4)-Tc(2)] / 2, the tube temperature rise rate k(n~n+2) from n seconds to n+2 seconds = [Tc(n+2)-Tc(n)] / 2, and ∑k is the cumulative value of the above tube temperature rise rates k.
[0070] In one exemplary embodiment, Ts is in the range of 10°C to 15°C, such as 10°C, 11°C, 12°C, 13°C, 14°C, 15°C, etc.
[0071] Of course, Ts is not limited to the above range and can be adjusted as needed during actual use.
[0072] In one exemplary embodiment, b is in the range of 5°C to 10°C, such as 5°C, 6°C, 7°C, 8°C, 9°C, 10°C, etc.
[0073] Of course, b is not limited to the above scope and can be adjusted as needed during actual use.
[0074] Two embodiments are described below with reference to the accompanying drawings.
[0075] Example 1 (e.g.) Figure 2 (As shown) Defrosting control methods include the following steps: Step S202: After entering defrost mode, periodically monitor the coil temperature Tc of the first heat exchanger; Step S204: Determine whether the coil temperature Tc of the first heat exchanger is greater than or equal to 0℃ and less than or equal to D; if yes, return to step S204; if no, proceed to step S206. Step S206: Obtain the duration t of the intermediate constant temperature stage and the ambient relative humidity a of the previous heating cycle, and calculate the target coil temperature Tquit according to the formula Tquit=a×t+b; Step S208: Determine whether the coil temperature Tc of the first heat exchanger is greater than or equal to the target coil temperature Tquit; if yes, exit the defrost mode; if no, return to step S208.
[0076] Example 2 (e.g.) Figure 3 (As shown) Defrosting control methods include the following steps: Step S302: After entering defrost mode, periodically monitor the coil temperature Tc of the first heat exchanger; Step S304: Determine whether the coil temperature Tc of the first heat exchanger is greater than D; if yes, proceed to step S306; if no, return to step S304. Step S306: Obtain the coil temperature Tc of the first heat exchanger at second set intervals, and calculate the coil heating rate k of the first heat exchanger within the second set interval; calculate the sum of all coil heating rates k calculated in the same final heating stage, and obtain the cumulative value ∑k of the coil temperature heating rate in the final heating stage that is updated periodically. Step S308: Calculate the target coil temperature Tquit according to the formula Tquit=Ts / ∑k+b; Step S310: Determine whether the coil temperature Tc of the first heat exchanger is greater than or equal to the target coil temperature Tquit; if yes, exit the defrost mode; if no, return to step S304.
[0077] like Figure 4 As shown, this application embodiment also provides a control device, including a processor 402 and a memory 404 storing a computer program. When the processor 402 executes the computer program, it implements the steps of any of the defrosting control methods in the above embodiments, and thus has all the above-mentioned beneficial effects, which will not be repeated here.
[0078] 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.
[0079] This application also provides a heat exchange device, which includes the control device described in the above embodiments, and thus has all the above-mentioned beneficial effects, which will not be repeated here.
[0080] In one exemplary embodiment, the heat exchange device is an air source heat pump unit, such as... Figure 5 As shown. Of course, it can also be used for other types of heat exchange equipment.
[0081] This application also provides a computer-readable storage medium storing a computer program thereon. When the computer program is executed, it implements the steps of the defrosting control method as described in any of the above embodiments, and thus has all the above-mentioned beneficial effects.
[0082] In summary, the defrosting control method, control device, and heat exchange equipment provided in this application have optimized and improved the determination conditions for ending the defrosting mode. The fixed and uniform conditions in traditional methods have been eliminated; instead, the target coil temperature for ending the defrosting mode is determined at least based on the defrosting stage information of the first heat exchanger. Since the defrosting stage parameter information of the first heat exchanger is related to the degree of frost formation, and this parameter information can qualitatively reflect the degree of frost formation, the target coil temperature determined at least based on the defrosting stage parameter information of the first heat exchanger can change with the degree of frost formation. This allows the target coil temperature to match the degree of frost formation of the first heat exchanger, which is beneficial for the heat exchange equipment to exit the defrosting mode at an appropriate time. This improves upon the problems of incomplete defrosting or excessively long defrosting times caused by traditional methods, thereby improving the operating efficiency of the heat exchange equipment.
[0083] 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.
[0084] 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.
[0085] 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 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.
[0086] 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 defrosting control method for a heat exchange device, the heat exchange device comprising a compressor, a reversing valve, a first heat exchanger, a throttling device, and a second heat exchanger connected via refrigerant piping, wherein the first heat exchanger is a heat exchanger requiring defrosting, characterized in that... The defrosting control method includes: In defrost mode, the first heat exchanger is defrosted; Determine the target coil temperature for ending the defrosting mode, the target coil temperature being determined at least based on the defrosting stage parameter information of the first heat exchanger; The defrosting mode is exited when the coil temperature of the first heat exchanger rises to a level greater than or equal to the target coil temperature. The defrosting stage of the first heat exchanger includes an initial heating stage, a mid-term constant temperature stage, and a final heating stage. The defrosting control method further includes: determining that the first heat exchanger is in the initial heating stage based on its coil temperature being less than 0°C; determining that the first heat exchanger is in the mid-term constant temperature stage based on its coil temperature being greater than or equal to 0°C and less than or equal to D; and determining that the first heat exchanger is in the final heating stage based on its coil temperature being greater than D; where D is the heat exchange temperature difference between the coil of the first heat exchanger and the ice-water mixture. The defrosting stage parameter information includes: the duration of the intermediate constant temperature stage; the target coil temperature is calculated according to the following formula: Tquit=a×t+b; where Tquit is the target coil temperature, a is the ambient relative humidity of the previous heating cycle, t is the duration of the intermediate constant temperature stage, and b is the compensation value of the coil temperature sensor.
2. The defrosting control method according to claim 1, characterized in that, The target coil temperature is positively correlated with the duration of the intermediate isothermal phase.
3. The defrosting control method according to claim 2, characterized in that, The target coil temperature is also positively correlated with the ambient relative humidity of the previous heating cycle.
4. The defrosting control method according to claim 3, characterized in that, The ambient relative humidity of the previous heating cycle was determined by the following method: During the previous heating cycle, the ambient relative humidity was detected and recorded at each first set interval. The average value of all ambient relative humidity recorded in the previous heating cycle is obtained by summing up all the ambient relative humidity values.
5. The defrosting control method according to any one of claims 1 to 4, wherein b is in the range of 5°C to 10°C.
6. The defrosting control method according to any one of claims 2 to 4, characterized in that, The value of D is in the range of 1°C to 3°C.
7. 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 defrosting control method as described in any one of claims 1 to 6.
8. A heat exchange device, characterized in that, Includes the control device described in claim 7.
9. The heat exchange device according to claim 8, characterized in that, The heat exchange equipment is an air source heat pump unit.