Multilayer spiral pipe type evaporator

The invention discloses a multilayer spiral pipe type evaporator. The multilayer spiral pipe type evaporator is characterized in that a heat exchange pipe bracket is arranged in an evaporator box; a spiral heat exchange pipe is formed to a spiral heat exchange pipe bundle of M circles*N layers by coiling a copper pipe from inside to outside with the center of the evaporator box as a circle center; and the spiral heat exchange pipe bundle is fully distributed in the evaporator box. The spiral heat exchange pipe bundle is fixed through the heat exchange pipe bracket; the diameter of the innermost circle of each layer of spiral heat exchange pipe is the same to form a cylindrical channel; and one end of the cylindrical channel is communicated with an exhaust pipe of an internal combustion engine, and the other end is sealed through a circular baffle plate. An inlet and an outlet of the spiral heat exchange pipe are positioned at an outlet end of the exhaust channel of the internal combustion engine. A liquid working medium flows in the spiral heat exchange pipe; and high-temperature waste gas exhausted by the internal combustion engine flows outside the spiral heat exchange pipe. The evaporator is compact in structure and identical in volume, and can increase the heat exchange area. The heat exchange pipe bundle is formed by coiling one spiral pipe, so that the contact heat resistance is reduced, and the heat efficiency of Rankine cycle is relatively improved.