Outdoor unit defrosting device of multi-split air conditioner system

Abstract

The invention discloses an outdoor unit defrosting device of a multi-split air conditioner system. A defrosting control system and a defrosting system are used, and the outer sides of multi-split outdoor unit fins are provided with an air speed sensor. When the surfaces of the outer sides of the multi-split outdoor unit fins are frosted, the air speed at an outdoor unit air inlet is reduced alongwith increasing of the thickness and the width of a frost layer; when the comprehensive air speed of the air speed sensor is reduced to a set threshold value and a defrosting point set by a defrostingcontroller is reached, the defrosting system is used for carrying out defrosting; after the air inlet speed of a unit reaches to a normal working speed, the air speed sensor sends an air speed signalto the defrosting controller after detecting and synthesizing the air speed, the defrosting controller carries out judgment according to a set value and then sends a defrosting command, and defrosting is completed. The outdoor unit defrosting device is simple in structure, the air speed sensor is used for judging the defrosting point accurately and reasonably, and the mistaken defrosting rate probability is greatly reduced; the defrosting effect is good, no unit energy is consumed, and the energy saving performance is good; and running is reliable, and control is convenient.

Description

technical field [0001] The invention belongs to the field of energy-saving research on multi-connected air-conditioning equipment for buildings, and in particular relates to a defrosting device for an outdoor unit of a multi-connected air-conditioning system. Background technique [0002] When the multi-connected air conditioning system is operating in winter, if the working environment of the outdoor unit has low temperature and high humidity, it is very easy to frost. The frosting problem of the outdoor unit brings many problems to the normal operation of the unit. Among them The most prominent thing is to reduce the operating performance of the unit. Therefore, the research on the defrosting problem of the multi-connected air-conditioning system has become a long-term research topic. Up to now, there are more than ten kinds of defrosting control methods for the unit, respectively. : Timing defrosting control method, temperature-time defrosting control method, self-correct...

AI Technical Summary

Problems solved by technology

[0002] When the multi-connected air conditioning system is operating in winter, if the working environment of the outdoor unit has low temperature and high humidity, it is very easy to frost. The frosting problem of the outdoor unit brings many problems to the normal operation of the unit. Among them The most prominent thing is to reduce the operating performance of the unit. Therefore, the research on the defrosting problem of the multi-connected air-conditioning system has become a long-term research topic. Up to now, there are more than ten kinds of defrosting control methods for the unit, respectively. : Timing defrosting control method, temperature-time defrosting control method, self-correcting defrosting control method, air pressure difference defrosting control method, maximum average heating capacity defrosting control method and more than ten kinds of defrosting control methods; fuzzy intelligent control Defrost method; refrigerant superheat defrost control method; fan current and evaporation temperature combined control defrost method; comprehensive frost index (FI) to judge defrost control method; indoor and outdoor dual sensor defrost control method; temperature difference Defrost control method; temperature difference-time defrost control method; however, although these defrost control methods are widely used, there are often "wrong defrosting problems" such as "defrosting with frost and defrosting without frost";

[0003] As for the defrosting methods of the unit, there are mainly electric defrosting, reverse cycle defrosting, hot gas bypass defrosting and energy storage defrosting; the common disadvantage of these defrosting methods is that the energy of the unit itself must be consumed for defrosting. This has a certain impact on the thermal comfort of the room and also reduces the operating performance of the unit.

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