What should be paid attention to during daily operation and maintenance of evaporator chiller?

　　What should be paid attention to during daily operation and maintenance of evaporator chiller?

　　1、 Maintenance of main components

　　(1) During operation, close attention should be paid to the exhaust and suction pressures of the system. If any abnormalities are found, the cause should be promptly identified and the fault eliminated.

　　(2) The setting points of control and protection components shall not be adjusted arbitrarily.

　　(3) Regularly check if the electrical wiring is loose, and if it is loose, tighten it in a timely manner.

　　(4) Regularly check the reliability of electrical components and replace faulty or unreliable components in a timely manner.

　　2、 Descaling

　　After long-term operation, Calcium oxide or other minerals will deposit on the water side heat transfer surface of the shell and tube heat exchanger of the unit. When these minerals deposit more on the heat transfer surface, they can affect heat transfer performance, increase power consumption, and exhaust pressure. Organic acids such as formic acid, citric acid, and acetic acid can be used for cleaning.

　　3、 On/Off

　　When shutting down in winter, the internal and external surfaces of the unit should be cleaned and blown dry; The drain valve must be opened to drain the water stored in the shell and tube heat exchanger to prevent freezing accidents.

　　3、 Spring startup

　　After a prolonged shutdown, when starting the unit, the following preparations should be made:

　　(1) Thoroughly inspect and clean the unit.

　　(2) Clean the water pipe system.

　　(3) Check the water pump.

　　(4) Tighten all wiring connectors.

　　(5) Preheat the compressor of the unit as required.

　　4、 Complete refrigerant leakage

　　In this case, use high-pressure nitrogen (15-20kg air pressure) or refrigerant to detect system leaks. If repair welding is required, the gas in the system must be discharged before welding. Before filling with refrigerant, the entire refrigeration system must be dry and vacuum.

　　Replenishing refrigerant:

　　(1) Connect the refrigerant filling bottle to the fluorine injection nozzle on the compressor suction pipe.

　　(2) Cycle frozen/cooling water and start the unit.

　　(3) Slowly inject refrigerant into the system and check the suction and exhaust pressure.

　　(4) Attention: During leak detection and airtightness testing, it is not allowed to charge oxygen, acetylene, etc. to the refrigeration system.

　　5、 System antifreeze

　　If the flow channel of the evaporator cooler is severely frozen, it may cause the evaporator cooler to crack and leak. Frost crack damage is not covered by the warranty, so special attention should be paid to the antifreeze performance of the unit. When the unit stops standby at a lower ambient temperature, if the outdoor temperature of the unit is below 0 ℃, the water in the evaporator and condenser must be discharged in the environment. The specific operation steps for drainage are shown in the drainage label of the entire machine.

　　During operation, if the chilled water flow switch fails, it may cause the water pipe to freeze, so the water flow switch must be interlocked with the unit. During maintenance, when filling the unit with refrigerant or placing the refrigerant for maintenance, the water in the evaporator may freeze. Be sure to keep the water in the evaporator flowing or completely clean the water.