A VALIDATION METHODOLOGY FOR A COMBINED HEATING COOLING AND POWER (CHCP) PILOT PLANT

A great number of variables significantly influence the energetic, environmental and economic results of CHP and CHCP plants operation, and as a consequence their p roject activity is rather complex. In order to select the best lay-out and properly si ze the machines, detailed data on hourly electric, thermal and cooling demand are necessary, so that a series of plant lif e cycle simulations may have to be carried out. Unfortunately, such detailed data are rarely availa ble, because energy consumptions data for existing buildings are usually derived from aggregated monthly or bi-monthly gas and electricity bills. Even more difficultie s are encountered for new types of buildings, for which no consumptio ns data are available. In such cases, the most common procedure consists i n performing, using case-oriented criteria, an esti mate of the thermal and cooling consumption levels, and to refi ne it during construction, if necessary. This is the case of an existing medium size CHCP pilot plan t for office buildings that covers the electrical, thermal and cooling loads of two office buildings situated in a Mediterranean area (Palermo, Sicily - Italy). Estimated demand profiles were used; the effect on thermal demand of the conversion of the cooling loa d into thermal one through an absorption chiller was assessed. Thi s is a very significant aspect in all warm climates zones. Cumulative curves were obtained for the aggregate t hermal demand, by summing the heat direct applications and the heat consumptions for feeding the absorption chille r. In this paper the existing plant was compared with other plant configurations, varying both for machin e sizes and management criterion, in order to affirm whether o r not the plant selected by the designer in a simpl ified manner was or not an appropriate solution. The comparison was performed from an energetic and economic viewpoint.