Refrigeration compressor is the most important equipment in the refrigeration system, which is equivalent to the "heart" of the refrigeration system ". Its function is: to suck the refrigerant vapor from the evaporator, increase its temperature and pressure, it will be discharged to the condenser.
Refrigeration compressor can be divided into two types: volume type and speed type. Volume type of compressor to the resurrection of the plug type, screw type (single screw, twin screw), scroll type, sliding vane type and rolling rotor compressor, etc.. Speed type compressor is mainly centrifugal compressor. According to the sealed structure, the compressor can be divided into an open type compressor, a semi hermetic compressor and a fully enclosed compressor. Today the main speakers is East Star industrial chillers used to two: piston type refrigeration compressor and screw type refrigerating compressor.
1, piston type refrigeration compressor
Piston type refrigeration compressor to take advantage of the reciprocating motion of the piston in the cylinder to compress the gas in a cylinder is usually the use of crank and connecting rod mechanism in the rotary motion of the original motivation change into a reciprocating linear motion of a piston, and therefore it is also called reciprocating refrigeration compressor, it is formed by the cylinder, gas valve and in the cylinder for reciprocating motion of the piston variable displacement, to complete the refrigerant gas suction, compression and discharge process of. Although there are many types of piston compressor, the structure is complex, but the basic structure and the main components are generally the same, including the body, crankshaft, connecting rod components, piston components, cylinders and suction and exhaust valve, etc..
Piston type compressor is widely used in medium and small sized cold water machine.
2, screw type refrigeration compressor
Screw refrigeration compressor is a volume type rotary compressor, according to the number of the screw rotor of screw compressor with two kinds of twin screw and single screw. Screw compressor for the twin screw compressor. Mainly used in screw type chiller. Screw refrigeration compressor structure is mainly composed of yin and Yang rotor, the body (including the cylinder body and suction and exhaust end seat), bearings, shaft seal, the balancing piston and the energy regulating device.
Screw refrigeration compressor by a pair of mutually engaged with the rotor (screw) to work. The rotor has a special spiral tooth shape, the convex tooth form is called the positive rotor, and the concave shape is called the negative rotor. The general positive rotor is the active rotor, which is directly connected with the original motive. Yang rotor general made 4 teeth, the female rotor made of 6 teeth, two rotor in the cylinder for reverse rotary motion, between the rotor slot and the cylinder body form V-shaped seal space. With the rotation of the rotor, the space volume changing, suction and discharge ports may according to need to accurately the rotor groove, and the suction, exhaust cavity communicated or obstructed, periodically complete suction, compression and exhaust process.
Screw refrigeration compressor has the advantages of simple structure, compact structure, less wearing parts, at high compression ratio under the condition of high volumetric efficiency, but due to the current most of the injection screw compressor, lubricating system complex, auxiliary equipment is larger. China's screw refrigeration compressor series, standard operating conditions in the range of 100~2300kw, between the piston compressor and centrifugal compressor.