LIGNITE DRYING IN A LIGNITE FIRED POWER PLANT WITH A HEAT PUMP

摘要

The invention relates to a lignite fired steam power plant comprising a water/ steam power cycle and a lignite dryer system having a heat pump circuit configured and arranged to provide heat energy to a lignite dryer (10) of the dryer system. The heat pump includes a dryer heat exchanger (13), an expansion device (17) and an evaporator heat exchanger (19) connected to the first outlet line (16) so as to enable heat energy transfer from the vapour of the first outlet line (16) to the first working fluid. A compressor (21) is also included in the heat pump circuit. In addition the heat pump circuit is connected to the water/steam power cycle by a steam makeup line (27) from the pressure series of steam turbines and a condensate return line (29).