Unveiling the mystery of combined heat & power (cogeneration)
Faculty of Applied Economics
Engineering sciences. Technology
Energy: the international journal. - Oxford
, p. 575-582
University of Antwerp
The article unveils the mystery of cogeneration. Cogeneration is an add-on or embedded activity in thermal power plants, with as merit the use of part or whole of their point source heat exhausts. EUs talk of high-efficiency cogeneration is an unfounded transfer of responsibility from the hosting thermal power generation plant onto CHP (Combined Heat & Power) activity. The quality of a CHP activity is univocally defined by its design power-to-heat ratio s, a tombstone parameter derived from the design characteristics of the power plant. A thermal power plant may house more than one cogeneration activity. Identifying s requires positioning the bliss point in the electricityeheat production possibility set of the cogeneration activity. The bliss point is where after electric output is maximized, the sum of that output and the maximum recoverable quantity of heat occurs. Once CHPs mystery of virtual bliss points is unveiled, the proper s are found. With known s by CHP activity, the quantity of cogenerated electricity is reliably assessed as best indicator of cogeneration performance. Our analysis is applicable on all relevant thermal power cycles that host CHP activities, and illustrated with a numerical example. Our lean method is necessary and sufficient for proper CHP regulation.