CN-122015357-A - Defrosting control method, device, equipment, storage medium and product of carbon dioxide heat pump

CN122015357ACN 122015357 ACN122015357 ACN 122015357ACN-122015357-A

Abstract

The application provides a defrosting control method, a defrosting control device, defrosting control equipment, a defrosting control device, a defrosting control storage medium and a defrosting control product for a carbon dioxide heat pump. The method comprises the steps of obtaining the ambient temperature of the environment where the heat pump is located and the relative humidity of ambient air where the heat pump is located, calculating the corresponding dew point temperature according to the ambient temperature and the relative humidity, carrying out fuzzy reasoning on the basis of the ambient temperature, the relative humidity and the dew point temperature to obtain a fuzzy set of defrosting demand of the heat pump, solving the fuzzy set to obtain an accurate defrosting demand value, and defrosting the evaporator on the basis of the difference value of the heat currently absorbed by the evaporator in the heat pump and the reference heat and the difference value of the current power of a fan in the heat pump and the reference power under the condition that the accurate defrosting demand value is larger than a first preset threshold value. Therefore, unnecessary defrosting energy consumption is reduced while the heat exchange efficiency is ensured, and the accuracy of defrosting judgment of the evaporator is improved.

Inventors

ZHU YINHAI
JIANG PEIXUE
WU GUOFENG

Assignees

清华大学
清华大学山西清洁能源研究院

Dates

Publication Date: 20260512
Application Date: 20260228

Claims (14)

1. A carbon dioxide heat pump defrost control method, the method comprising: acquiring the ambient temperature of the environment where the heat pump is located and the relative humidity of the ambient air where the heat pump is located; calculating a corresponding dew point temperature according to the ambient temperature and the relative humidity; Fuzzy reasoning is carried out based on the ambient temperature, the relative humidity and the dew point temperature, so as to obtain a fuzzy set of defrosting demand degrees of the heat pump; Solving the fuzzy set to obtain an accurate defrosting demand degree value; And under the condition that the defrosting demand degree accurate value is larger than a first preset threshold value, defrosting the evaporator based on the difference value between the current absorbed heat of the evaporator in the heat pump and the reference heat and the difference value between the current power of the fan in the heat pump and the reference power.
2. The carbon dioxide heat pump defrost control method according to claim 1, wherein, in the case where the defrost demand level precision value is greater than the first preset threshold value, defrosting the evaporator based on a difference between a current heat absorbed by the evaporator in the heat pump and a reference heat, and a difference between a current power of a fan in the heat pump and a reference power, comprises: Under the condition that the defrosting demand degree accurate value is larger than the first preset threshold value, calculating the current heat absorbed by the evaporator in the heat pump and the current power of the fan in the heat pump according to the current state of the evaporator and the current state of the fan respectively; And defrosting the evaporator under the condition that the heat quantity is reduced by a first preset value compared with the reference heat quantity or the current power is increased by a second preset value compared with the reference power.
3. The defrosting control method of the carbon dioxide heat pump according to claim 2, wherein the calculating the current heat absorbed by the evaporator in the heat pump and the current power of the fan in the heat pump according to the current state of the evaporator and the current state of the fan respectively comprises: calculating the heat currently absorbed by the evaporator in the heat pump according to the current refrigerant state at the inlet and the current refrigerant state at the outlet of the evaporator in the heat pump; And calculating the current power of the fan in the heat pump according to the current input voltage and current of the fan.
4. The defrosting control method of the carbon dioxide heat pump according to claim 3, wherein the calculating the heat currently absorbed by the evaporator in the heat pump according to the current state of the refrigerant at the inlet and the state of the refrigerant at the outlet of the evaporator in the heat pump comprises: obtaining a first specific enthalpy of the refrigerant at the inlet according to the current temperature of the refrigerant at the inlet of the evaporator in the heat pump and the specific heat capacity of the refrigerant at the inlet; Obtaining a second specific enthalpy of the refrigerant at the outlet according to the current temperature of the refrigerant at the outlet of the evaporator in the heat pump and the specific heat capacity of the refrigerant at the outlet; and calculating the current absorbed heat of the evaporator according to the difference value of the first specific enthalpy and the second specific enthalpy and the current refrigerant flow of the evaporator.
5. The carbon dioxide heat pump defrost control method according to claim 1, wherein said calculating a corresponding dew point temperature according to said ambient temperature and said relative humidity comprises: determining a saturated water vapor pressure value corresponding to the ambient temperature based on a preset low-temperature correction term; obtaining an actual water vapor pressure value in the current environment according to the saturated water vapor pressure value and the relative humidity; And carrying out iterative solution based on the actual water vapor pressure value through a dew point temperature relation determined according to the preset low-temperature correction term to obtain a corresponding dew point temperature.
6. The carbon dioxide heat pump defrost control method according to claim 1, wherein after said solving said fuzzy set, obtaining a defrost demand level accurate value, said method further comprises: when the defrosting demand degree accurate value is larger than or equal to a second preset threshold value and smaller than or equal to a first preset threshold value, calculating the reference heat absorbed by the evaporator according to the current refrigerant state at the inlet and the refrigerant state at the outlet of the evaporator in the heat pump; and calculating the reference power of the fan according to the current input voltage and current of the fan in the heat pump.
7. The carbon dioxide heat pump defrost control method according to claim 1, wherein in the case where the defrost demand level precision value is greater than the first preset threshold value, the method further comprises, after defrosting the evaporator based on a difference between a heat currently absorbed by the evaporator in the heat pump and a reference heat, and a difference between a current power of a fan in the heat pump and a reference power: detecting an evaporator temperature in the case of defrosting; and stopping defrosting under the condition that the duration that the temperature of the evaporator is higher than the preset temperature exceeds the preset duration.
8. The carbon dioxide heat pump defrost control method according to claim 7, wherein, in the case where the duration in which the evaporator temperature is higher than a preset temperature exceeds a preset duration, after stopping defrosting, the method further comprises: Under the condition of stopping defrosting, calculating recovered heat absorbed by an evaporator in the heat pump and recovered power of a fan in the heat pump; determining a corresponding first heat value, a first power value, a second heat value and a second power value according to the reference heat and the reference power in a preset proportion, wherein the second heat value is smaller than the first heat value, and the second power value is smaller than the first power value; Reducing the preset temperature by a preset value under the condition that the recovered heat is larger than the first heat value or the recovered power is larger than the first power value; and increasing the preset temperature by a preset value under the condition that the heat after recovery is smaller than the second heat value or the power after recovery is smaller than the second power value.
9. The carbon dioxide heat pump defrost control method according to claim 1, wherein said fuzzy inference based on said ambient temperature, said relative humidity and said dew point temperature, obtaining a fuzzy set of defrost demand of said heat pump, comprises: Converting the ambient temperature, the relative humidity, and the dew point temperature into corresponding amounts of blur; Matching each fuzzy quantity with a preset fuzzy rule base, and determining the triggering strength corresponding to each fuzzy rule in the fuzzy rule base; and applying corresponding fuzzy rules on the original fuzzy set based on the triggering intensity to obtain the fuzzy set of the defrosting requirement degree of the heat pump.
10. The defrosting control method of a carbon dioxide heat pump according to claim 1, wherein the solving the fuzzy set to obtain the defrosting demand level accurate value comprises: sampling the fuzzy set to obtain membership values corresponding to all quantization levels of the fuzzy set; multiplying each quantization level by a corresponding membership value to obtain each corresponding weighting moment; and obtaining the defrosting demand precision value based on the sum of the weighted moment.
11. A carbon dioxide heat pump defrost control apparatus, said apparatus comprising: The acquisition module is used for acquiring the ambient temperature of the environment where the heat pump is positioned and the relative humidity of the ambient air where the heat pump is positioned; The calculating module is used for calculating the corresponding dew point temperature according to the ambient temperature and the relative humidity; the reasoning module is used for carrying out fuzzy reasoning based on the ambient temperature, the relative humidity and the dew point temperature to obtain a fuzzy set of defrosting requirement of the heat pump; the solving module is used for solving the fuzzy set to obtain a defrosting demand precision value; and the defrosting module is used for defrosting the evaporator based on the difference value between the current absorbed heat of the evaporator in the heat pump and the reference heat and the difference value between the current power of the fan in the heat pump and the reference power under the condition that the defrosting demand precision value is larger than a first preset threshold value.
12. A carbon dioxide heat pump defrost control apparatus, characterized in that the apparatus comprises a processor and a memory storing computer program instructions, the processor reading and executing the computer program instructions to implement the carbon dioxide heat pump defrost control method according to any one of claims 1-10.
13. A computer readable storage medium, wherein computer program instructions are stored on the computer readable storage medium, which when executed by a processor, implement the carbon dioxide heat pump defrost control method according to any one of claims 1-10.
14. A computer program product, characterized in that instructions in the computer program product, when executed by a processor of an electronic device, cause the electronic device to perform the carbon dioxide heat pump defrost control method according to any one of claims 1-10.

Description

Defrosting control method, device, equipment, storage medium and product of carbon dioxide heat pump Technical Field The application relates to the technical field of heat pump control, in particular to a carbon dioxide heat pump defrosting control method, a device, equipment, a storage medium and a product. Background When the air source heat pump operates in a low-temperature high-humidity environment, the surface of the evaporator is easy to frost, so that the heat exchange efficiency is reduced, the energy consumption is increased, and the heating performance and the operation reliability of the system are seriously affected. Especially for a heat pump system adopting carbon dioxide transcritical circulation, due to high operating pressure, higher evaporating temperature and large fluctuation of working conditions, defrosting misjudgment, frequent start and stop or delayed defrosting are easily caused, and the influence of frosting and defrosting processes on the system stability is more prominent, so that the energy efficiency and the service life of the system are reduced. The current commonly adopted defrosting control method depends on indirect or single judgment indexes and lacks direct response to the physical critical conditions of defrosting. This results in erroneous judgment of defrosting timing which frequently occurs in actual operation, and it is possible that defrosting is started at a time which is not always necessary, resulting in waste of energy, or that defrosting is not performed in time when the performance of the frost layer has been seriously affected. In the prior art, the accuracy and the working condition adaptability of defrosting judgment are insufficient, so that the system is frequently started and stopped, and the energy efficiency is reduced. Disclosure of Invention The embodiment of the application provides a defrosting control method, a defrosting control device, defrosting control equipment, a defrosting control storage medium and a defrosting control product for a carbon dioxide heat pump, and aims to solve the technical problem that defrosting judgment in the related art is insufficient in accuracy. In a first aspect, the present application provides a defrosting control method for a carbon dioxide heat pump, the method comprising: acquiring the ambient temperature of the environment where the heat pump is located and the relative humidity of the ambient air where the heat pump is located; calculating a corresponding dew point temperature according to the ambient temperature and the relative humidity; Fuzzy reasoning is carried out based on the ambient temperature, the relative humidity and the dew point temperature, so as to obtain a fuzzy set of defrosting demand degrees of the heat pump; Solving the fuzzy set to obtain an accurate defrosting demand degree value; And under the condition that the defrosting demand degree accurate value is larger than a first preset threshold value, defrosting the evaporator based on the difference value between the current absorbed heat of the evaporator in the heat pump and the reference heat and the difference value between the current power of the fan in the heat pump and the reference power. In some possible implementations, in the case where the precision value of the defrosting demand is greater than the first preset threshold, defrosting the evaporator based on a difference between the heat currently absorbed by the evaporator in the heat pump and a reference heat, and a difference between the current power of the fan in the heat pump and the reference power, includes: Under the condition that the defrosting demand degree accurate value is larger than the first preset threshold value, calculating the current heat absorbed by the evaporator in the heat pump and the current power of the fan in the heat pump according to the current state of the evaporator and the current state of the fan respectively; And defrosting the evaporator under the condition that the heat quantity is reduced by a first preset value compared with the reference heat quantity or the current power is increased by a second preset value compared with the reference power. In some possible implementations, the calculating the current heat absorbed by the evaporator in the heat pump and the current power of the fan in the heat pump according to the current state of the evaporator and the current state of the fan respectively includes: calculating the heat currently absorbed by the evaporator in the heat pump according to the current refrigerant state at the inlet and the current refrigerant state at the outlet of the evaporator in the heat pump; And calculating the current power of the fan in the heat pump according to the current input voltage and current of the fan. In some possible implementations, the calculating the heat currently absorbed by the evaporator in the heat pump according to the current refrigerant state at the inlet and the current refrigerant