Experimental investigation on heat transportation over long distance by ammonia–water absorption cycle

An ammonia–water absorption cycle is suggested to transport heat over long distance, in which thermal energy is transferred into chemical energy in the heat source site by the change of solution concentration. So there is no heat insulation requirement for the transportation pipelines. In the user site the chemical energy could be released with heating or cooling. An experimental prototype has been built to investigate the system performance. The experiments include two parts: heating is obtained from absorber (user site) in transition season by ammonia–water absorption heat pump cycle, in which a hot water outlet temperature at about 64 °C can be reached and the system COP is 0.47 (absorption temperature at 66 °C). Cooling is obtained from evaporator (user site) in summer by ammonia–water absorption refrigeration cycle, in which a chilled medium outlet temperature at about 8 °C can be reached and the system COP is 0.43 (evaporation temperature at 4.6 °C). The investigation of the transportation parameters also shows that the pump electric consumption can be reduced greatly in comparison with the conventional heat transportation method. The ammonia–water absorption cycle is a potential and efficient way of heat transportation over long distance.