Maintenance and Troubleshooting of Cryogenic Water Chillers

2022/08/07 ClassificationIndustry News 240

Maintenance and Troubleshooting of Cryogenic Water Chillers

The ultra-low temperature chiller is composed of five parts: compressor, condenser, evaporator, filter drier, and expansion throttle valve. The regular maintenance of the chiller plays a key role in the long-term stable operation of the equipment. Therefore, it must be Establish a complete maintenance mechanism.

The maintenance process and phenomenon of the ultra-low temperature chiller are as follows:

cryogenic water chiller

(1) After the chiller stops running, the user needs to use the refrigerant recovery device to recover the refrigerant.

(2) After the refrigerant recovery is completed, open the end cover of the water chamber, clean the circulating water system, replace the filter element, and check the safety valve.

(3) After the overhaul and installation are completed, vacuum the system with a vacuum pump and keep the pressure for 24 hours, and the airtightness is good.

(4) During the process of charging refrigerant, it was found that the refrigerant could not be inhaled, and it was confirmed that the system was leaking. After analyzing the above maintenance process, it can be found that there is no abnormality from the shutdown of the chiller to the cleaning of the water chamber, the replacement of components, and the entire installation process. It can be concluded.

Therefore, it can be determined that the water inflow of the chiller system occurs during the charging of refrigerant. When charging the refrigerant, the cooling water must circulate normally, and when charging the refrigerant, the pressure inside the equipment is negative pressure, which aggravates the vaporization of the refrigerant.

Ultra-low temperature chiller troubleshooting measures:

1. Find leaks

Close the inlet and outlet valves on the water side of the evaporator and condenser. After emptying the water in the machine, open both ends of the water side covers of the evaporator and condenser, and fully close the outlet valve of the compressor to form a closed space on the freon side of the evaporator and condenser. . The external pressure is 2MPa, oil-free, dry nitrogen gas is passed into the freon side, and then the position of the leaking copper pipe on the water side is marked. After inspection, there are 3 copper pipes leaking in the condenser. blocked.

2. Evaporator and condenser drying

First, pressurize the inside of the machine with nitrogen to basically discharge the residual liquid water in the system from the bottom filling valve, and fill the system with about 0.2Mp of nitrogen, and slowly open the exhaust valve at the top of the ultra-low temperature chiller to remove There is residual air in the system. Repeat this for many times to ensure that all the air in the system is exhausted. Then fill the system with about 0.4Mp nitrogen, and open the bottom angle valve of the evaporator and condenser to discharge the residual liquid water in the system, and repeatedly flush until no residual liquid water is discharged.

In the process of further vacuuming and drying the ultra-low temperature chiller system, the method of drying and hot nitrogen blowing is used to first fill the evaporator and condenser with water, and the whole steam pipe is separated by a low-in and high-out method. Connect it to the bottom drain valve at one end of the evaporator and condenser, open the exhaust valve at the top of the other end at the same time, control the amount of steam influx, heat the water to 70~80℃, and evacuate until the vacuum degree no longer rises. Pour dry nitrogen into the machine to blow out the water vapor in the system. Repeat until the vacuum level in the system meets the maintenance requirements. At the beginning, the oil level of the vacuum pump rose due to the water being drawn out, and the vacuum was continued after the oil change.

3. Handling of compressors

First remove the motor, then dry it, and perform a pressure test by a professional; then disassemble the compressor body, carry out overall inspection, maintenance, and replace damaged parts, such as gaskets, oil pumps, etc.; and then assemble the compressor as a whole.

Our ultra-low temperature chillers have a cooling temperature range of -150℃~-5℃, fast cooling speed, safe and reliable, and are used for rapid liquid cooling. They adopt secondary subcooling technology and a full set of cooling controls to achieve rapid cooling and low cooling temperature.

We are a professional manufacturer of temperature control equipment, supporting customized services, please consult us for details!