Defrosting control method and air source heat pump system

A control method and air technology, applied in the direction of control input involving air characteristics, space heating and ventilation, space heating and ventilation control input, etc., can solve problems such as false defrosting faults, energy loss, and threats to the safe operation of the unit , to achieve the effect of low cost, simple structure and easy promotion and use

Inactive Publication Date: 2019-07-05
QINGDAO ECONOMIC & TECHN DEV ZONE HAIER WATER HEATER
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] In order to solve the technical problems of inaccurate judgment of defrosting conditions for existing air source heat pumps, prone to false defrosting faults, resulting in energy loss, and threatening the safe operation of the unit, the present invention proposes a defrosting control method that can solve the above problems

Method used

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  • Defrosting control method and air source heat pump system
  • Defrosting control method and air source heat pump system
  • Defrosting control method and air source heat pump system

Examples

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Embodiment 1

[0030] Embodiment 1. When the air source heat pump is in heating operation under the condition of low ambient temperature in winter, frost usually forms on the surface of the finned tubes of the evaporator. During the frosting process, the distribution of the frost layer on the surface of the finned tubes and the The temperature of the finned tube is related to the temperature of the surface of the finned tube and the flow and heat transfer characteristics of the low-temperature refrigerant in the tube. Studies have shown that when the low-temperature refrigerant flows in the tube, the pressure of the refrigerant will gradually decrease due to the frictional resistance of the tube wall. The impact of resistance pressure drop is very large, and the change of refrigerant flow rate is related to the gas-liquid ratio of refrigerant. The larger the proportion of liquid (the greater the mass), the smaller the refrigerant flow rate (usually between 0.5-1.0m / s) , with the heat absorpt...

Embodiment 2

[0052] Embodiment 2, this embodiment proposes a heat pump system, including a compressor and an evaporator, such as figure 2 As shown, the evaporator of this embodiment includes a coil tube 12 and a coil tube 12 fixed on the fin 11, and a fan (not shown in the figure) is also arranged on one side of the fin 11 and the coil tube, and the fin 11 It is perpendicular to the coil 12 to form a finned tube. The fan is located on one side of the finned tube. When the fan is running, the air sucked flows through the finned tube structure and exchanges heat with the low-temperature refrigerant in the coiled tube 12. During the heating process of the heat pump system The flow direction of the refrigerant is shown by the arrow. A first temperature sensor 13 is installed near the refrigerant inlet of the evaporator, and a humidity sensor 14 is installed at the air inlet of the evaporator to detect the relative humidity φ of the air at the air inlet of the evaporator. A temperature sensor ...

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Abstract

The invention discloses a defrosting control method and an air source heat pump system. The defrosting control method comprises the following steps that (1) the relative humidity phi of air at an airinlet of an evaporator is detected, and a temperature detection period T is determined according to the relative humidity phi of the air; (2) the air temperature Ts near a refrigerant inlet of the evaporator is detected by taking the temperature detection period T as a period, and a difference value of the air temperatures Ts detected at different two moments is calculated; and (3) a system entersa defrosting process if the temperature difference value in the step (2) is not less than a first set threshold, otherwise, the system runs a heating process. A defrosting judging mechanism of the defrosting control method is based on the growth characteristics and distribution rules of a frost layer in the frosting process of the evaporator, and the judgment is accurate, so that the phenomenon that a conventional double temperature sensor method frequently mistakenly defrosts in a cold and dry environment is avoided, and the energy efficiency ratio and the reliability of system running are greatly improved.

Description

technical field [0001] The invention relates to the technical field of defrosting control, in particular to a defrosting control method and a heat pump water heater. Background technique [0002] When the air source heat pump is running in winter, the outdoor heat exchanger usually frosts. When the frost layer reaches a certain thickness, the heat exchanger needs to be defrosted. At present, the most widely used defrosting method is indoor / outdoor Dual temperature-time method, this method is simple, cheap, and easy to implement, but it is often used in cold and dry conditions (such as North China), but accidental defrosting accidents often occur. Research shows that under this condition, "no frost" "Defrosting" accidents accounted for as high as 70% of the total number of defrosting times, resulting in a significant loss of the effective heat supply of the system, a sharp drop in COP, and a threat to the safe operation of the unit, greatly reducing the reliability of the sys...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): F24F11/41F24F11/64F25B39/02F28F1/24F24F110/10F24F110/20
CPCF25B39/02F28F1/24F24F11/41F24F11/64F24F2110/10F24F2110/20
Inventor 赵洪运高本法庄长宇蒋建平彭海燕
Owner QINGDAO ECONOMIC & TECHN DEV ZONE HAIER WATER HEATER
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