Self-adaptive defrosting control method of air-cooled heat pump system

Abstract

The invention discloses a self-adaptive defrosting control method of an air-cooled heat pump system. The self-adaptive defrosting control method is characterized by comprising the following steps of:setting four control parameters: (1) setting a defrosting time set value; (2) setting a temperature difference value entering a defrosting cycle; (3) setting a fin temperature exiting the defrosting cycle; and (4) setting an interval time (defrosting cycle) of two defrosting cycles, comparing actual defrosting time with set defrosting time, recording a ratio of the actual defrosting time to the set defrosting time each time, setting an interval according to a ratio range, determining a defrosting interval time according to an interval range to which the defrosting interval time belongs, takingtwo times of defrosting time as a correction interval, adjusting the set value of the defrosting interval time according to two defrosting time intervals recorded by the current times and the previous times, and continuously correcting the defrosting cycle to enable the defrosting cycle to automatically adapt to the change of the temperature and humidity of the environment with a self-correctionvariable step length.

Description

technical field [0001] The invention relates to the technical field of defrosting control methods, in particular to an adaptive defrosting control method for an air-cooled heat pump system. Background technique [0002] When the system is cooling or heating, frosting may occur. If defrosting is not timely after frosting, it will affect the use of the refrigeration system or heating system. [0003] Refrigeration and frosting are generally located on the evaporator of the indoor unit. When cooling, the outdoor unit dissipates heat and the indoor unit absorbs heat. The purpose of the evaporator is to absorb heat (cool down), and absorbing heat requires air circulation, which is carried away by air conduction. Heat, when the air flow is insufficient, the evaporator will frost, and the reason for insufficient air is often that the filter screen is not cleaned or the cooling fins of the evaporator are not cleaned, which hinders the air flow. [0004] Heating frost is usually loc...

AI Technical Summary

Problems solved by technology

Since the temperature is considered on the basis of the time, it is an improvement over the simple time method, and partly considers the influence of the outdoor working environment of the air conditioner, but it still cannot correctly reflect the impact of frost on the performance of the air conditioner, and unnecessary defrosting operation, and will not send a defrosting signal when defrosting is required

[0009] (3) The defrosting control method of the difference between the evaporation temperature and the atmospheric temperature: when the frost on the surface of the evaporator is serious, the difference between the evaporation temperature and the atmospheric temperature will increase, and the defrosting control according to this change reflects the working characteristics of the air conditioner after frosting The influence produced, but judging only based on the change of a quantity will also cause misoperation

[0010] (4) When frosting on the surface of the evaporator is serious, the condensation temperature will decrease. Controlling defrosting according to the change of condensation temperature and the heating operation time reflects the influence of frosting on the working characteristics of the air conditioner, but it is only based on the change of one quantity Judgment is the simplest situation under laboratory conditions, and the change of condensing temperature in the actual use process is not only affected by the frosting of the evaporator, but also affected by the indoor and outdoor ambient temperature, the wind speed of the indoor unit, the auxiliary power The influence of factors such as heating, unloading, and temperature-controlled shutdown

Therefore, if these influencing factors are not considered, there will be a phenomenon that the frost thickness does not defrost or no frost does not defrost

[0011] However, the automatic defrosting systems commonly used in the market are not stable enough and have large errors, which cannot guarantee the stability of the unit during operation. The performance of defrosting directly affects the normal operation of the refrigeration / heating system and the entire set of equipment. working life

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