Double-machine-head screw parallel low-temperature water chilling unit

The utility model discloses a double-machine-head screw parallel low-temperature water chilling unit which comprises a unit bottom frame. The air conditioning unit is characterized in that the top of the unit bottom frame is provided with a shell and tube type water-cooled condenser, an exhaust header, a return air header, a semi-sealed screw compressor, an economizer assembly, a dry filter, a system electromagnetic valve, a dry evaporator, an electric appliance control box, an oil cooler, an external oil separator and a shell and tube type water-cooled condenser; one end of the shell and tube type water-cooling condenser is connected with the drying filter in a penetrating mode, the other end of the shell and tube type water-cooling condenser is connected with the external oil separator in a penetrating mode, one end of the external oil separator is connected with the oil cooler, and the other end of the external oil separator is connected with the exhaust collecting pipe in a penetrating mode. One end of th