Chillers refrigerant circulation, water cycle, electrical control and maintenance
The working principle of the chiller
The industrial chillers consist of three interrelated systems: a refrigerant circulation system, a water circulation system, and an electrical control system.
Refrigerant circulation system
The liquid refrigerant in the evaporator absorbs the heat in the water and begins to evaporate. The liquid refrigerant is completely evaporated into a gaseous state and is sucked and compressed by the compressor. The gaseous refrigerant absorbs heat through the condenser, condenses into a liquid, passes through a thermal expansion valve Or capillary) after the throttle into low-temperature low-pressure refrigerant into the evaporator to complete the refrigerant cycle process.
The basic components of the refrigeration system:
Compressor: The compressor is the core component of the refrigeration system, the role is to convert the input power into mechanical energy, compressed refrigerant.
Condenser: During the cooling process, the condenser acts to output heat and condense the refrigerant. After the high pressure superheated steam discharged from the refrigeration compressor enters the condenser, it is transferred from the evaporator and the refrigeration compressor and the heat absorbed in the pipe to the surrounding medium (water or air); the refrigerant high pressure superheated steam Re-condense into liquid.
Storage device: The accumulator is installed in the condenser and is in direct communication with the drain of the condenser. The refrigerant liquid of the condenser should flow unimpeded into the reservoir so that the cooling area of the condenser can be fully utilized. On the other hand, when the heat load of the evaporator is changed, the amount of the refrigerant liquid is also changed, and the accumulator functions to adjust and store the refrigerant.
Drying filter: In the refrigeration cycle must be to prevent moisture and dirt (oil, iron, copper) and other entry, if the system of water is not ruled out, when the refrigerant through the throttle (thermal expansion valve or capillary) , Due to pressure and temperature drop Sometimes the water will solidify into ice, so that the channel block, affecting the normal operation of the refrigeration device.
Thermostatic expansion valve: The thermostatic expansion valve is a flow regulating valve and a throttle valve in the refrigeration system. It is installed between the drying filter and the evaporator in the refrigeration equipment. The temperature sensing package is wrapped in the outlet of the evaporator At the office. Its main role is to make high-pressure room temperature refrigerant liquid flow through the thermal expansion valve when the throttle down into low-temperature low-pressure refrigerant wet steam (into the evaporator, vaporization in the evaporator heat absorption, and to achieve the purpose of cooling cooling.
Evaporator: The evaporator is a heat exchange device that relies on the evaporation of the refrigerant liquid to absorb the heat of the cooled medium. Its function in the refrigeration system is to absorb heat (or output cooling). In order to ensure that the evaporation process can be stable and lasting, must continue to use the refrigeration compressor to evaporate the gas away to maintain a certain evaporation pressure.
Refrigerant: R22 as refrigerant. Its role is to carry heat, and in the state changes to achieve endothermic and exothermic.
Water circulation system
The water circulation system is the water pump from the water tank to the user to cool the equipment, chilled water will be taken away after the heat temperature, and then back to the frozen water tank.
Electrical control system
The electrical control system includes the power part and the automatic control part.
Power supply part is through the contactor, the compressor, fans, pumps and other power supply.
Automatic control part includes thermostat, pressure protection, delay, relay, overload protection and other combinations to achieve according to the water temperature automatically start and stop, protection and other functions.
The work of the industrial chiller before running
The machine is installed in a solid place, in order to facilitate the operation and maintenance, the machine should be around 1 meter above the space, no heat, no harmful gases, steam and flammable gas to ensure that the machine is not polluted and safe operation.
The machine should be placed at a distance from the power supply, the supply of water and the wiring is convenient and the place should be equipped with drainage pipes around the machine. If the machine is placed in open air, it should be equipped with rainproof and sunscreen.
The installation of the machine should pay attention to the ventilation and ventilation equipment should be configured to ensure that the ambient temperature of the machine does not exceed 35 ℃; cold areas, to ensure that the ambient temperature of the machine is not less than zero, so as to avoid freezing the machine.
The pipe size specifications connected to the machine should be changed according to the specifications of the technical data sheet.
(5m) connected to the control unit switch must be connected to the power supply. In this case, the ground terminal (E) must be connected. Otherwise, it will be mistaken for operation due to misoperation and leakage.
Machine water supply
Close the water tank drain valve, open the water supply valve, water supply valve, cold water output valve, cold water input valve.
For the cooling water and refrigerant water temperature, flow, the user should be based on technical data provided on the table, otherwise it will cause the machine can not work properly.
Check before the machine is running
1.Check whether the inlet and outlet valves of the mold are open.
2.Check the cold water tank is sufficient water, water, water supply is normal.
3.Check the entire piping system is sufficient water, the air is drained.
4.Check whether the supply voltage is normal.
5.Check whether the ground wire is firmly connected.