Energy: Diesel Heat Pump for District Heating Plants and for the Heating of Large Housing Blocks

摘要

The technical, economic, and environmental aspects of large diesel-driven heat pump plants for district heating or very large building heating was investigated. Possible heat sources, e.g., air, ground, and surface and waste waters, geothermal and solar sources were studied and the operation of existing district heating plants was analyzed. The possibility of using other prime movers such as gas turbines, coal-fired steam turbines and electric motors was examined for cost and efficienty. It was found that technically it is possible to construct diesel driven heat pumps in the 5 to 20 MW size range, yielding energy savings of typical 50%. At present energy prices such plants are profitable. The investigation of possible heat sources for such large heat pump gave the result that several water sources, such as sewage water, ground water, sea water, river water, and lake water could be used without problems. The use of low temperature geothermal heat looks favorable, but has to be investigated further. The diesel engine is the most economic and effient prime mover for the heat pump, but prime movers like gas engines, coal fired steam turbines and electric motor can be used, which gives a flexibility with respect to the primary energy supplies. Gas engines and electrically driven heat pumps were found to be the best solutions for small towns up to 2500 inhabitants, diesel and dual fuel engine driven heat pumps for towns with 2500 to 20,000 inhabitants, and combined heat and power production on the basis of coal (and nuclear) for large towns. (ERA citation 05:030819)