High temperature absorption compression heat pump for industrial waste heat

Heat pumps are currently receiving extensive interest because they may be able to support the integration of large shares of fluctuating electricity production based on renewable sources, and they have the potential for the utilization of low temperature waste heat from industry. In most industries, the needed temperature levels often range from 100°C and up, but until now, it has been quite difficult to find heat pump technologies that reach this level, and thereby opening up the large-scale heat recovery in the industry. Absorption compression heat pumps can reach temperatures above 100°C, and they have proved themselves a very efficient and reliable technology for applications that have large temperature changes on the heat sink and/or heat source. The concept of Carnot and Lorenz efficiency and its use in the analysis of system integration is shown. A 1.25 MW system having a Carnot efficiency higher than 82% by the better temperature match of the process to the heat sink and source is reported. Another major benefit of using ammonia and water as working pair is the possibility of reaching quite high temperatures at a significantly lower operating pressure, which makes it possible to reach a temperature of 108°C using standard industrial refrigeration equipment as described in the three included realized systems.