Waste heat generating system and generating method

The invention discloses a waste heat generating system and a generating method. The generating system generates power by using the heat energy stage-stored in a multi-stage heat energy storage system; the generating system comprises a generator, a steam turbine, an ammonia turbine and an absorption heat pump; the multi-stage heat energy storage system delivers steam to the steam turbine, and the steam turbine converts the heat energy into dynamic mechanical energy and drives the generator to convert the mechanical energy into electrical energy; the absorption heat pump adopts ammonia-water as working medium, and converts the low-quality heat energy of the steam at the tail end of an output of the steam turbine into higher-quality heat energy; and the heat energy storage system provides a high-quality driving heat source for the heat pump so that a large amount of mixed solution of concentrated ammonia-water is evaporated under high pressure to form high-pressure saturated ammonia, and the high-pressure saturated ammonia drives the ammonia turbine to convert the pressure produced by the ammonia into mechanical energy, and delivers the mechanical energy to the generator. The generating system and the generating method overcome the defects that the heat-electricity conversion efficiency in the conventional waste heat generating process is low and the like, and achieve the purposes of high quality, high efficiency and low consumption.