Abstract

The designer of refrigeration or heat pump plants must have a clear understanding of how his choice of design parameters for the plant will effect the power input needed to run the plant. Knowing in the first instance the combination of ideal processes which wili give the desired refrigeration or heating effect he must then evaluate how the actual processes involved depart from the ideal. It is the function of this article to explain how these departures from the ideal in any given process contribute to the cycle work input and to state clearly how this work quantity may be calculated. The described methods can be universally applied. They can be used to evaluate losses due to the temperature differences needed for heat transfer in heat exchangers, losses due to heat transfer from or to the working fluid in compressors and losses due to friction effects such as those occurring in heat exchanger tubes, throttle valves and lines and in the ports of the compressor.