Thorough defrosting method for air source heat pump unit

Abstract

The invention discloses a thorough defrosting method for an air source heat pump unit. The method comprises the following steps that temperatures of different positions of a defrosted fin type heat exchanger are obtained; an absolute value of a difference value between the temperatures of each two different positions is calculated; if each absolute value meets a preset temperature range, the thorough defrosting requirement is met; and if not all the absolute values meet the preset temperature range, the thorough defrosting requirement is not met. According to the method, the basic conditions of defrosting can be automatically judged, and the defrosting logic is intelligently selected, so that thorough defrosting is achieved; and through the method, the heat exchange effect of the fin typeheat exchanger is improved, the energy efficiency ratio of the unit is increased, and the load of a compressor is reduced due to the fact that defrosting can be carried out in time, so that the service life of the compressor is prolonged.

Description

technical field [0001] The invention generally relates to the technical field of heat exchange, in particular to a method for thoroughly defrosting an air source heat pump unit. Background technique [0002] When the air source heat pump unit works in the heating mode, the fin heat exchanger acts as an evaporator to absorb energy in the air. Since the temperature of the fins in this working mode is relatively low (-20~-5°C), the water in the air When the steam is cold, it will form dew or frost (when frost is formed, the ambient temperature is generally around -10-5°C, and the temperature of the fins is lower than the ambient temperature). When the frost reaches a certain thickness, the air source heat pump unit will perform The defrosting function, at this time, the refrigerant flow direction is switched through the four-way reversing valve, and the heat pump unit is changed from the heating mode to the cooling mode. At this time, the fin heat exchanger acts as a condenser ...

AI Technical Summary

Problems solved by technology

"There is frost and defrost, no frost does not melt" is an ideal state, and the ideal state can basically be realized in the simulated artificial environment laboratory, but in reality, due to various reasons such as manufacturing errors, inconsistencies in parts processing, equipment Factors such as the size of the installation space and environmental changes lead to the finned heat exchanger 3 ( figure 2 ) of the dispensing head assembly 2 ( image 3 ) liquid distribution is not uniform, so that there are differences in frosting in different areas of the fins. Some places have thick frost and some places have thin frost. The thickness is getting thicker and the area is getting bigger and bigger, resulting in lower energy efficiency of equipment and poor heating effect

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