Two media resorption compression heat pump with solution circuit

Abstract

A new type of heat pump resp. refrigeration machine, which was recently successfully tested in operation, will be described. It is an energy saving two media resorption compression heat pump resp. refrigeration machine with solution circuit working with ammonia-water mixture. The comparison of this new type with a common heat pump resp. refrigeration machine working with a single substance will be discussed theoretically and practically. Assuming the same maximum and minimum temperatures in both systems the ratio of COPs of both systems can reach considerable values in favor of the new type of machine, especially when the temperature drop by cooling and/or the temperature rise by heating is large. A pilot plant of a resorption compression heat pump of about 500 kW capacity was recently tested. The obtained values correspond to the calculated COPs, so that the theoretical advantages of the two media resorption compression heat pump with solution circuit compared with the heat pump working with a single substance were fully confirmed in the practical operation. In conclusion it can be said that with the same investments great energy savings can be obtained with this new type of heat pump or refrigeration machine. Furthermore, due to the favorable properties of the ammonia-water mixture, temperatures of up to 200°C can be obtained. This range of temperatures cannot be obtained with a common heat pump working with a single substance. This is especially important for heat pumps used in industry, because there are often great quantities of waste heat and a process steam of some bar above atmospheric pressure is required.