Mapping of general combined heat and power systems

In a combined heat and power (CHP) plant, the heating and electrical loads are mutually exclusive and cannot be chosen independent of each other. This paper reports on the mapping of the ranges of the heat-to-power ratios (HP Rs) for given fractions of the electrical output. Alternatives for matching the HPRs of the CHP plant (source) and target process (load) are also disc ussed, It is shown that the maximum overall efficiency of CHP plants is abo ut 90%. Design equations for the overall efficiency and HPRs of Diesel gene rating sets, boiler-steam turbine-generator units and combined cycle plants have been provided as a function of the fraction of the electrical output for optimal and rational design of the systems, (C) 2000 Elsevier Science L td. All rights reserved.