Adopt high-efficiency semi-hermetic screw compressor with high quality and reliability and long service life. 2. The unit adopts single or multiple independent refrigeration systems, and the unloading capacity is doubled. Multiple compressors can be operated in a balanced manner. 3. The control center provides various protection functions such as high pressure, low pressure, overpressure, under-voltage, phase loss, phase imbalance, overload, and over-temperature to ensure safe and stable operation of the unit. 4. The compact and precise assembly unit coves a tiny area and can greatly save the user’s installation costs. 5. The compressor can be started at a small load position. Through a series of lubrication, the capacity can be adjusted within the load range of 100%-25%, ensuring the complete development of the compressor and flexibly meeting the needs of the user’s cooling capacity.