Full-condition efficient evaporation cooled screw parallel-connection thermo-syphon flooded type low-medium temperature water chilling unit

The invention discloses a full-condition efficient evaporation cooled screw parallel-connection thermo-siphon flooded type low-medium-temperature water chilling unit and relates to the field of industrial refrigeration. The water chilling unit comprises a screw type compressor parallel machine unit, an oil-gas separator, an exhaust pressure sensor, an oil level switch, a lubricating oil temperature sensor, a thermo-siphon oil cooler, an oil temperature three-way self-operated regulating valve, an oil supply differential pressure self-operated regulating valve, an evaporation type condenser, a high-pressure liquid reservoir, an energy saver, a liquid level control type regulating valve, a thermo-siphon flooded type evaporator, a low-pressure recycling gas-liquid separator, a liquid level switch, an ejecting oil scavenger, an electric control box, relative pipelines, valves and gauges. By means of the system, the coefficient of performance (COP) of an industrial refrigerating unit can be increased by over 30%, the maintenance cost of the industrial refrigerating unit can be reduced by over 50%, and therefore the industrial refrigerating unit can operate more safely, more reliably and more stably.