The role of the general principle of refrigerator refrigeration compressor is to compress the low pressure steam into high pressure steam, reduce the volume of steam, pressure.
Compressor suction from the evaporator working medium low pressure steam, after pressure into the condenser, cold high pressure of the liquid condensed in the condenser, the throttle valve throttle, become low pressure liquid, into the evaporator, the evaporator of heat to evaporate and become a low pressure steam, and then into the entrance of the evaporator, thus complete the refrigeration cycle.
1, steam compression refrigeration principle of single-stage vapor compression refrigeration system, is by the refrigeration compressor, condenser, evaporator and throttle four basic parts.
Between them in turn connect pipe to form a closed system, the refrigerant in the system constantly circulating, status changes, the heat exchange with the outside world.
Liquid refrigerant in the evaporator absorbed by the object of cooling heat, vaporized into the low temperature low pressure steam, in the compressor, compressed into high-temperature high-pressure steam back into the condenser, the condenser to the cooling medium (
With air or water)
Exothermic, condensation of high pressure liquid, the throttle valve throttle for low pressure low temperature refrigerant, again into the evaporator heat vaporization, and achieve the goal of cycle refrigeration.
In this way, the refrigerant in the system after evaporation, compression, condensation, throttle four basic process to complete a refrigeration cycle.
In the refrigeration system, evaporator, condenser, compressor and throttle valve is the indispensable four items in the refrigeration system, the evaporator is conveying equipment of cold energy.
In which refrigerant absorbing heat cooling objects to realize refrigeration.
Compressor is the heart, plays a suction, compression, the role of the refrigerant vapor.
Condenser is exothermic equipment, will be absorbed in the evaporator heat along with the heat transformation by the compressor work is passed to the cooling medium away.
Throttle valve throttling depressurization effect to the refrigerant, at the same time control and adjust the number of flows into the evaporator refrigerant liquid, and the system is divided into the high side and low voltage side of two parts.
Actual refrigeration system, in addition to the above four items, often has some auxiliary equipment, such as solenoid valve, distributor, dryer, collector, fusible plug, pressure controller and other parts, they are in order to improve the operation of the economy, reliability and security.
2, air-conditioner refrigeration system main components according to the condensation forms can be divided into: water-cooled and air-cooled type two kinds, according to the purpose can be divided into single cooler type warming and cooling system type two kinds, which one type of composition, is made up by the following main components.
Refrigeration system main components with compressor, condenser, evaporator, expansion valve,
Or capillary, cooling control valve)
, four-way valve, double valve, check valve, solenoid valve, pressure switch, plug, output pressure regulator, pressure controller, storage tank, heat exchanger, collector, filter, dryer, automatic shutter, the cut-off valve, the liquid slug injection, and other parts.
Electrical system main components with motor (
Compressor, blower etc)
, chain operation switch, electromagnetic contactor, relay, over current relay, thermal over-current relay, temperature controller, humidity controller, temperature switch (
Defrost, prevent freezing, etc)
Compressor crankcase heater, water relays, PC board and other parts.
Control system is composed of multiple control devices, they are: refrigerant controller: expansion valve, capillary, etc.
Refrigerant loop controller: four-way valve, check valve, double valve, solenoid valve.
Refrigerant pressure controller: shutter, output pressure regulator, pressure controller.
Motor protector: over-current relay, thermal over-current relay, temperature relay.
Temperature controller, temperature regulator, temperature ratio regulator.
Humidity regulator, humidity regulator.
Defrost controller: defrosting temperature switch, defrosting time relay switch, all kinds of temperature.
Water cooling water control: relay, water valve, water pump, etc.
Alarm control: overtemperature alarm, super wet under-voltage alarm and alarm, fire alarm, smoke alarm, etc.
Other control: indoor fan speed controller, the outdoor fan speed controller, etc.
3, commonly used refrigerants and their properties of refrigerant sort is more, now is a brief introduction of the freon 12 and 22: a.
Freon 12 (
Code R12 freon 12 is a colorless, odorless, transparent, non-toxic almost refrigerants, but the content is more than 80% in the air can cause suffocation.
Freon 12 won't burn will not explode, when contact with open flame or when the temperature is above 400 ℃, can decompose harmful to human body of hydrogen fluoride, hydrogen chloride and phosgene (
Refrigerant R12 is applied in a wide range of temperature, suitable for small and medium-sized refrigeration system, such as refrigerators, freezers, etc.
R12 can dissolve many kinds of organic matter, so can't use the general rubber gasket (
, often use chloroprene artificial rubber or butyl rubber or seal.
Freon 22 (
Code R22 refrigerant R22, not burning explosion toxicity slightly bigger than a R12, water solubility is bigger than R12, but still can make the refrigeration system & other;
Ice jam & throughout;
R22 can partially and the lubricating oil dissolve each other, its solubility with lubricating oil type and temperature change, therefore using R22 refrigeration system must have the oil return measures.
Corresponding to the evaporation temperature of R22 under standard atmospheric pressure for -
8 ℃, temperature condensing pressure no more than 15.
105 Pa, refrigerating capacity and the unit volume is bigger than R12 by more than 60%.
In air conditioning equipment, mostly choose R22 refrigerant.