In the process of using the screw chiller, the chiller is mainly driven by various types of screw compressors. Under normal circumstances, the user will select the compressor of the screw chiller according to the cooling capacity under actual working conditions. Capacity, but with the change of ambient temperature and application load, it may be necessary to change the gas volume of the compressor to match the actual heat release, so as to achieve the economic operation of the chiller.
The energy regulation function of the screw chiller is that its equipment can automatically adjust the input power of the compressor according to the load size, reducing unnecessary energy consumption. The commonly used energy adjustment function can be adjusted by the slide valve adjustment and the plug valve. In addition, there are methods such as frequency adjustment, turn-by-turn adjustment, and refrigerant suction and throttling adjustment.
The specific method of the screw chiller is to effectively provide an axially movable slide valve between the two rotors in the screw compressor. When the spool moves axially, a through hole is formed in the radial direction of the rotor. The gas that has been sucked into the screw is returned to the suction chamber through the bypass hole without being compressed. The return flow of the gas increases as the axial movement distance of the spool increases, so that the gas volume of the compressor is equivalent to a reduction. The slide valve can adjust the gas delivery volume continuously within the range of 10~100%. However, when the spool adjusts the gas transmission volume below 50%, the coefficient of performance will drop drastically, which appears to be economically poor.
The screw compressor can use the solenoid valve to control the opening and closing of the plug valve to achieve a stepwise adjustment of the gas volume. Most screw chillers can now achieve 33%-66%-100% or 25%-50%-75%-100% adjustment of gas delivery.
Screw chillers are widely used in various industrial applications and commercial locations due to their compact structure, high cooling energy efficiency ratio, low failure rate and long unit life. By using single or multiple compressor refrigeration systems, screw chillers can cover applications ranging from 100kw to 3000kw.
