Energy and materials conversion with the help of regeneration and energy transformation
International Journal of Thermal Sciences, 40 (4):
316 - 328 (2001)DOI: 10.1016/S1290-0729(01)01221-2
Abstract
The comprehension of the unity of materials and energy conversion is the basis for energetic effective design of materials conversion processes. Besides regenerative heat utilisation energy transformation can open up further possibilities of energy saving. The principal procedure for the design of energetic effective regenerative heat transfer systems and the effects which are within reach with regeneration are shown through the instance of a brewery — a typical multilevel heat consumer. Brewery process offers possibilities for heat transformation both in open and closed cycles. For the purpose of an equally good description of heat fluxes and material fluxes in open heat transformation processes, a concept for exergetic evaluation of material fluxes is necessary. Normalised exergy and corresponding generalised temperature are developed as evaluation characteristics and illustrated with help of an energy–entropy diagram. Heat transformation in the sense of open cycles appears also in single processes or unit operations. Aspects of energy transformation in connection with materials conversion are discussed through the examples of absorption and dehumidification. The regard of chemical reactions from the view of heat transformation opens interesting aspects for the evaluation of the conversion potential of fuels and other chemical compounds. This is discussed for some thermochemical cycles, reversible combustion and fuel cell.