Defrosting method of fresh-air machine system

Abstract

The invention relates to a defrosting method of a fresh-air machine system. The defrosting method is applied to the fresh-air machine system. The defrosting method includes: detecting the outlet temperature of an air exhausting heat exchanger under the mode of heating of the fresh-air machine system; when the outlet temperature of the air exhausting heat exchanger is lower than a first set temperature, enabling the fresh-air machine system to enter and run in the defrosting mode, namely enabling a fresh-air fan to run at a low speed for stop running, enabling an air exhausting fan to run at a high speed, and enabling a compressor to stop running; when the time of the defrosting mode reaches the set defrosting time or the detected outlet temperature of the air exhausting heat exchanger is higher than a second set temperature, allowing the fresh-air machine system to restore to the heating mode. By the application of the method, the problem about frosting of the air exhausting heat exchanger and a main heat exchanger can be solved under the winter running heating mode, noises brought by switching of a four-way valve can be avoided, and indoor temperature reduction caused by the fact that fresh air is too low in temperature can be prevented.

Description

technical field [0001] The invention relates to a method for removing frost on a main heat exchanger and an exhaust air heat exchanger when heating in winter in a fresh fan system. Background technique [0002] The existing new fan system is attached figure 1 As shown, it includes compressor, exhaust air heat exchanger, fresh air heat exchanger, plate heat exchanger (main heat exchanger), fresh air fan, and exhaust fan. The fresh air fan is set relative to the fresh air heat exchanger, and the exhaust fan is relatively The exhaust air heat exchanger is set, and the compressor, the exhaust air heat exchanger and the fresh air heat exchanger are connected as a circuit through pipelines, and a four-way valve and a throttling device are also arranged on the circuit. [0003] In summer, the fresh air fan system operates in cooling mode. The fresh air introduced from the outside at 26°C~43°C and the return air at 24°C~26°C inside the room first exchange heat in the plate heat exc...

AI Technical Summary

Problems solved by technology

[0007] 1. During forced cooling, the temperature of the fresh air in the room will be very low, thereby reducing the indoor temperature;

[0008] 2. During forced cooling, the switching of the four-way valve will cause a large noise, which will cause dissatisfaction among users of the fresh air system;

[0009] 3. This method cannot solve the frosting problem of the plate heat exchanger

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