Screw chillers can be divided into air-cooled screw chillers and water-cooled screw chillers according to different heat dissipation methods. The water-cooled screw chiller uses the cooling tower water circulation system to dissipate heat, while the air-cooled screw chiller uses finned air to dissipate heat. During the working process of the unit, there will definitely be some impurities due to water quality or air problems, or because the refrigerated oil is turbid, which will affect the entire refrigeration system. Do cleaning and maintenance.
So, how to clean the refrigeration system of the screw chiller?
1. How to determine that the refrigeration system of the screw chiller needs to be cleaned?
First of all, we have to observe whether the oil color of the compressor refrigeration oil of the screw chiller turns brown? If so, it means that the oil quality is cloudy. Secondly, check whether the smell is burnt, and check the resistance value of the motor winding in the compressor. If the resistance value between the winding and the shell is normal, it means that the insulation is good. Otherwise, the refrigeration oil must be replaced and the refrigeration system must be cleaned.
Here, I would like to remind everyone: In the water system of the chiller, impurities will adhere to the inner wall of the pipe more or less. If the unit runs for a long time and there are too many impurities, the drying filter will be blocked and the unit will not be able to cool. Therefore, it is recommended to clean the heat exchanger every six months and clean the system every year.
2. What should be done before cleaning the refrigeration system?
For the pollution in the refrigeration system pipeline, cleaning agent can be used to clean it. Before cleaning, it is necessary to release the refrigerant in the refrigeration system, then remove the compressor, and pour out the refrigerant oil from the process pipe. During the cleaning operation, first remove the compressor and the dry filter, then disconnect the capillary (or expansion valve) from the evaporator, connect the evaporator to the condenser with a pressure-resistant hose, and then use a A hose firmly connects the cleaning equipment with the suction and discharge pipes of the compressor. Then clean the equipment used, such as pumps, tanks, filters, dryers, and various valves.
The cleaning process is as follows: first inject the cleaning agent into the liquid tank, then start the pump, make it run, and start cleaning. When cleaning, perform multiple operations in forward and reverse directions until the cleaning agent does not show acidity. For mild pollution, it only needs to circulate for about 1 hour. For severe pollution, it takes 3-4 hours. If it is cleaned for a long time, the cleaning agent is dirty, and the filter is also clogged and dirty. The cleaning agent and the filter should be replaced before performing this operation. After the system is cleaned, the cleaning agent is dirty and the filter is also clogged and dirty. The cleaning agent in the liquid reservoir should be recovered from the liquid pipe. After cleaning, nitrogen blowing and drying should be carried out on the refrigeration pipeline, and then filled with fluorine, and the unit debugging work should be carried out to ensure the normal operation of the chiller.
The power of the screw chiller is relatively large, and there is a choice of single head or double head. The single-head screw chiller has only one compressor, which can be adjusted in four stages from 100% to 75% to 50% to 25%. The twin-head screw chiller is composed of 2 compressors and has two independent systems. When one of them fails or needs maintenance, the other can be used normally, which is very convenient to use.
Post time: Feb-01-2023
