Screw compressor classification is divided into: fully enclosed, semi-enclosed, open type screw compressor. As a kind of rotary refrigeration compressor, screw compressor has the characteristics of both piston type and power type (speed type).
1), compared with reciprocating piston refrigeration compressor, screw refrigeration compressor has a series of advantages such as high speed, light weight, small size, small footprint and low exhaust pulsation.
2), screw type refrigeration compressor has no reciprocating mass inertia force, good dynamic balance performance, smooth operation, small vibration of the frame, the foundation can be made smaller.
3), screw refrigeration compressor structure is simple, the number of parts is small, there is no wearing parts like valve, piston ring, its main friction parts such as rotor, bearing, etc., strength and wear resistance are relatively high, and lubrication conditions are good, so the processing amount is small, material consumption is low, the operation cycle is long, the use is more reliable, simple maintenance, is conducive to the realization of control automation.
4) Compared with the speed compressor, the screw compressor has the characteristics of forced gas transmission, that is, the exhaust volume is almost not affected by the exhaust pressure, the surge phenomenon does not occur in the small exhaust volume, and the high efficiency can still be maintained in a wide range of working conditions.
5), the use of slide valve adjustment, can achieve stepless energy regulation.
6), screw compressor is not sensitive to liquid intake, you can use oil injection cooling, so under the same pressure ratio, the discharge temperature is much lower than the piston type, so the single-stage pressure ratio is high.
7), no clearance volume, so the volume efficiency is high.
The core structure of screw compressor is oil circuit equipment, suction filter, check valve, system protection device and cooling capacity control.
(1) Oil circuit equipment
Includes oil separator, oil filter, oil heater, oil level.
(2) Suction filter
It is used to eliminate impurities in the medium to protect the normal use of valves and equipment. When the fluid enters the filter cartridge with a certain size filter screen, its impurities are blocked, and the clean filtrate is discharged through the filter outlet.
(3) Check valve
Stop to prevent high-pressure gas from returning to the compressor from the condenser, to prevent the impact of reverse pressure on the compressor and the resulting reversal of the rotor.
(4) System protection device
Exhaust temperature monitoring: lack of oil will cause a sudden rise in exhaust temperature, the electronic protection module can monitor the exhaust temperature.
Pressure difference switch HP/LP: use its on-off ability to control on-off, in order to ensure that the equipment can be closed in time under abnormal pressure protection equipment.
Oil level control: It is recommended to use an oil level monitor to strictly control the oil level in these applications (long pipe arrangement, condenser remote arrangement)
(5) Cooling capacity control
According to the cooling capacity of 100-75-50-25% adjustment, the slide block has 4 corresponding positions, the slide block is directly connected with the slide valve moving in the hydraulic cylinder, the position of the slide valve is controlled by the solenoid valve actual shape of the slide valve to change the suction port.
Post time: Jun-13-2024