The motor for refrigeration compressor, as the most important part of the chiller, occupies an important position in the after-sales maintenance of the chiller. And, the maintenance cost of chiller compressor is relatively high. In order to reduce the chiller maintenance cost, the chiller compressor is protected from the following four aspects. To achieve the purpose of reducing chiller maintenance costs.
First, to prevent liquid shock
Second, under normal operating conditions, industrial chiller refrigeration compressor should be inhaled refrigeration medium of dry vapor, if the refrigeration medium flow, heat load change too quickly, improper operation may inhale wet vapor, or liquid medium, or worse, there is lubricating oil into the cylinder, if too much liquid into the discharge valve from the exhaust, the pressure inside the cylinder will be dramatically higher to form a liquid shock, is the cylinder, valve, piston, connecting rod and other parts are damaged. The cylinder, valve, piston, connecting rod and other parts are damaged. Therefore, various types of protective measures can be taken, such as the installation of gas-liquid separator, so that entrained in the low-pressure vapor in the liquid separation, to ensure that the compressor’s dry stroke; the installation of oil heaters, in the compressor before the start of the lubricating oil to join, reduce the amount of refrigerant dissolved in the lubricating oil; or the valve assembly with a spring pressed tightly on the end of the cylinder to form a false cover.
Pressure protection
1, suction and discharge pressure control: that is, we often say high and low pressure controller, by the high-pressure control part and low-pressure control part of the composition. If the exhaust pressure exceeds the given value, the high-pressure control part of the compressor cuts off the power supply, the compressor stops; suction pressure is lower than the given value, the low-pressure control part of the compressor cuts off the power supply, so that the compressor stops and sends out an alarm signal.
2, safety valves: to prevent refrigerant leakage to the atmosphere, generally used closed safety valves, safety valves are set in the chiller compressor exhaust chamber and suction chamber between the pipeline.
3, safety film: safety diaphragm installed in the suction and discharge chamber, suction and discharge pressure difference exceeds the prescribed value, the diaphragm rupture, exhaust pressure reduction (need to be installed in the suction side of the chamber filter, to prevent the broken diaphragm fell into the suction chamber).
4, lubricating oil differential pressure controller: the hydraulic pump inlet and hydraulic pump outlet and lubricating oil differential pressure controller on the low-pressure inlet, high-pressure outlet connection, when the hydraulic pump outlets and inlets between the pressure difference is too high or too low, the controller will cut off the compressor power supply, the motor stops running to protect the compressor.
Third, the built-in motor protection
Overheating protection, in order to further ensure that the motor does not overheat, in addition to the correct use, pay attention to maintenance, can also be installed overheating relay; there is also phase protection, commonly used three-phase motor phase will lead to the motor can not start or overload, can be used to avoid damage to the motor due to lack of phase overload relay.
Temperature protection
The temperature mentioned here refers to the exhaust temperature and the chassis temperature of the industrial chiller. Exhaust temperature protection method is mainly placed in the thermostat near the exhaust port, sensed that the exhaust temperature is too high, the thermostat action to cut off the circuit; set of shell temperature is too high will affect the life of the compressor, mainly due to the condenser’s heat transfer capacity caused by the lack of adequate, it is necessary to check the condenser air volume or water volume, water temperature is appropriate. And check whether the refrigeration system is mixed with air or other non-condensable gases, or the suction temperature is too high, it should be observed and tested.
Post time: Jan-08-2024
