Fuel and product in the exergetic analysis of refrigeration systems.

The ratio between the generically called Product and Fuel of a refrigeration system gives the measure of its efficiency. The misevaluation of the Fuel and Product of a part, or the entire system, can lead to fallacious conclusions getting finally to the interpretation that a specific zone of a refrigeration system is or too weak or too performing. In both cases many opportunities of optimization are lost. The estimation of the Fuel and Product is made based on exergetic analysis. A methodology of assessing the correct cost to each exergy destruction and exergy loss is presented. Applications are made for a compression refrigeration system a heat pump and the key parts of these systems as compressor and heat exchangers. The proper estimation of each internal unitary cost leads to find out the best operating regime and design for the considered refrigeration system.