Double-unit double-stage screw refrigerating unit

The utility model relates to a double-unit double-stage screw-type refrigerating unit which comprises a high-pressure-stage screw-type compressor, the high-pressure-stage screw-type compressor is connected and communicated with a shell-and-tube condenser, the shell-and-tube condenser enables steam of a high-temperature and high-pressure R410A refrigerating machine to release heat and be liquefied, and the high-pressure-stage screw-type compressor is communicated with the shell-and-tube condenser. The shell-and-tube condenser is connected with the intercooler and the intercooler thermal expansion valve through the liquid storage device, the intercooler is connected with the economizer and the economizer thermal expansion valve, the economizer is connected with the evaporator through the thermal expansion valve, the evaporator is connected with the low-pressure-stage screw compressor, and the low-pressure-stage screw compressor is connected with the liquid storage device. The other end of the low-pressure-stage