Central air conditioner and method for controlling flow of refrigerant therein

Abstract

The invention provides a central air conditioner and a method for controlling the flow of a refrigerant therein. The central air conditioner comprises an evaporator, a condenser, an electronic expansion valve, a liquid level meter and a controller, wherein the electronic expansion valve is connected to a refrigerant pipeline between the evaporator and the condenser; the liquid level meter is connected with the evaporator or the condenser; the controller is used for controlling the opening of the electronic expansion valve and is provided with an input port and an output port; the input port of the controller is connected with a signal sending end of the liquid level meter; and the output port of the controller is connected with a signal receiving end of the electronic expansion valve. Themethod comprises the following steps of: at the operation stage of the central air conditioner, sending a real-time refrigerant liquid level L1 of the evaporator or the condenser detected by the liquid level meter to the controller; and comparing L1 with a first target liquid level L and adjusting the opening of the electronic expansion valve according to a comparison result to ensure that L1 approaches L and is finally equal to L by using the controller. The liquid impact of a pressing machine can be avoided, and the control accuracy of the flow of the refrigerant is improved.

Description

technical field [0001] The invention relates to a central air conditioner and a method for controlling the refrigerant flow in the central air conditioner. Background technique [0002] Central air conditioners are widely used in large buildings and have the characteristics of large heat exchange and high energy efficiency. Taking the refrigeration and air conditioner in the prior art as an example, the refrigerant is compressed into a high-temperature and high-pressure gas by the compressor, then condensed into a liquid by the condenser, and then evaporated and absorbed by the evaporator after passing through the throttling device, so as to achieve the purpose of refrigeration. In this cycle process, when the structure of the central air-conditioning unit and the refrigerant are fixed, the main factor affecting the cooling capacity and energy efficiency ratio of the unit is the control of the refrigerant flow. The current method of controlling the refrigerant flow is reali...

AI Technical Summary

Problems solved by technology

The problems in this control precision link will directly lead to liquid hammer and affect the life of the compressor

Not only when starting up, but also when the load changes frequently, the control accuracy will be greatly affected by the ambient temperature and working conditions.

This shortcoming is fatal to the magnetic levitation centrifugal unit, because the maximum speed of the compressor of this unit reaches 50,000 rpm, and the liquid shock can easily damage the impeller of the compressor and make the compressor scrapped

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