Hydraulic filling type central air-conditioning unit

Abstract

The invention discloses a hydraulic filling type central air-conditioning unit and belongs to the technical field of central air-conditioning. The hydraulic filling type central air-conditioning unit comprises a compressor, a condenser, an expansion valve, an evaporator and a control unit for controlling a machine unit to run and further comprises a bypass pipe enabling a high-pressure refrigerant in the condenser to be led into the evaporator. The bypass pipe is provided with a solenoid valve controlling on-off of the bypass pipe, the evaporator is provided with a temperature sensor for detecting outflow water temperature, and the temperature sensor and the solenoid valve are electrically connected with the control unit. When the temperature of outflow water of the evaporator is larger than a set value, the compressor and the expansion valve are turned off, the high-pressure refrigerant is led into the evaporator by opening the bypass pipe, evaporating temperature of the refrigerant is improved, the speed of lowering the water temperature is slowed down, water in the evaporator is kept flowing continuously, the compressor and the expansion valve are restarted until the water in the evaporator reaches a certain temperature, and accordingly freezing of the evaporator is avoided.

Description

technical field [0001] The invention relates to the technical field of central air-conditioning units, in particular to a flooded central air-conditioning unit. Background technique [0002] The flooded central air-conditioning unit belongs to the vapor compression air-conditioning unit, and usually includes two types: the flooded water-cooled central air-conditioning unit and the flooded ground-source heat pump central air-conditioning unit. High-end features, currently used in buildings, but the application of flooded central air conditioners has the problem of evaporator freezing. The evaporator is a component used for heat exchange. Through the heat exchange between the flowing water and the flowing refrigerant, the heat of the water is transferred to the refrigerant, so that the temperature of the water drops, causing the evaporator to freeze, especially when the flooded ground source heat pump central air conditioning unit is heated in winter Under working conditions,...

AI Technical Summary

Problems solved by technology

[0002] The flooded central air-conditioning unit belongs to the vapor compression air-conditioning unit, and usually includes two types: the flooded water-cooled central air-conditioning unit and the flooded ground-source heat pump central air-conditioning unit. High-end features, currently used in buildings, but the application of flooded central air conditioners has the problem of evaporator freezing. The evaporator is a component used for heat exchange. Through the heat exchange between the flowing water and the flowing refrigerant, the heat of the water is transferred to the refrigerant, so that the temperature of the water drops, causing the evaporator to freeze, especially when the flooded ground source heat pump central air conditioning unit is heated in winter Under working conditions, the temperature of the working environment is low, and the refrigerant in the evaporator absorbs the heat of the water in the evaporator when it vaporizes, making the evaporator easier to freeze. service life, if it is heavy, it will cause the unit to lose its function and be completely scrapped

[0003] At present, the anti-freezing method of the evaporator is to detect the water temperature at the outlet of the evaporator when the unit is running normally. If the water temperature is lower than the set value, the unit will be shut down; when the outlet water temperature rises to the set value, the unit can be restarted. However, this method has the following Several disadvantages: 1. In actual operation, although the unit is shut down, the refrigerant in the evaporator still evaporates, and the water in the evaporator continues to cool down. There is still a danger of freezing, and this method cannot solve the problem of evaporator waterway freezing when it cannot run completely normally; 2. When the flooded central air-conditioning unit system suddenly loses power, the water pump stops running, and the water in the evaporator basically stops flowing. The refrigerant in the evaporator continues to evaporate, the water side temperature continues to drop, and the unit is very prone to evaporator freezing

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