Introduction
The surplus-heat recovery unit uses high temperature heat reservoir as driving source to produce large amount of useful heat energy of middle temperature. Driven by high temperature source, low-grade thermal power is heated to middle temperature so that it can improve the efficiency. Coefficient of Performance is about 1.5~2.5.

Driving source:
the extraction steam for heating from the steam turbine，high temperature water, combustible gas

Usable surplus heat:
exhausted steam from combined heating and power cogeneration system, circular cool water from heat power plant, waste hot water separated from crude oil extraction, iron-slagging water, municipal sewage，geothermal water，hot spring and solar energy, etc. that can be used directly or through heat-exchange machine.

Heat gained：can get heat medium whose temperature is higher than wasted heat source by about 40℃ but no higher than 100℃
         
The surplus heat of the exhausted steam recycling unit is used to recover the surplus heat of air cooling islands. The maximum recollection competence of a single machine is 120 MW.
The recovery unit of the surplus heat from water cycle is used to recollect the surplus heat of the water cycle in the cooling tower. The maximum recollection competence of a single machine is 20 MW.