Wave-tide direct-driven water-pumping pressure-accumulation sea water desalination machine

The invention provides a device for performing sea water desalination by using waves and tides to directly drive a water-pumping pressure-accumulation pump. The device consists of a sea water desalination system and a wave-tide direct-driven water-pumping pressure-accumulation device. A vane wing unit captures water to ensure that a turbine main shaft rotates along a fixed direction, rotational mechanical energy can be directly transferred to a water-pumping screw, sea water is sucked into a sea water pipeline to accumulate pressure continuously, and finally fresh water is generated through a reverse osmosis system. The sea water desalination machine disclosed by the invention makes use of the advantage that a wave-tide turbine rotates along a fixed direction, and a water-pumping screw pump matched with the wave-tide turbine is designed, so that the mechanical energy can be directly transferred to reduce intermediate energy consumption; on the other hand, an accumulator and a valve control type energy recovery device are used for performing flexible treatment on the water pressure of the sea water desalination system, so that the desalination pressure is sufficient while a reverse osmosis membrane is protected. The device provided by the invention can solve the problem of lack of fresh water of ships, naval vessels and offshore islands, and can meet requirements for energy conservation and sustainability.