EVALUATION OF CONCEPTS FOR A 10 kW REVERSIBLE ABSORPTION HEAT PUMP

摘要

In the last decade, several sorption chillers with small to medium scale cooling capacity have been developedrn(Jakob and Kohlenbach 2010). In Northern and Middle Europe, however, the heating period is longer thanrnthe cooling period. Therefore, sorption heat pumps should rather be used for heating than for cooling in thisrnregion to be economically competitive. A reversible set-up allows a year-round operation. This shortens thernpayback period and increases the cost effectiveness of thermally driven heat pumps.rnThe technology of heat pumps often is discussed separately from heat sink and heat source. Nevertheless, thernsystem context always has to be considered. This applies in particular for reversible heat pumps since forrnswitching between heating and cooling mode a change in the connection between the heat pump and thernbuilding as well as between the heat pump and the ambient is necessary. There are a lot of parametersrninfluencing the decision concerning favorable heat sources and heat sinks. In principle, the same heat sourcesrnand heat sinks as for conventional compression heat pumps are possible, but there are some restrictions duernto the third temperature level being involved (the driving temperature) and due to the properties of thernnatural refrigerant water (freezing temperature of 0℃) and the non-toxic absorbent aqueous LiBr solutionrn(crystallization at high concentration) for the case of using this working pair.rnIn this paper, an evaluation tool is described which allows a discussion of sensitivities of varying parametersrnaccording to the point of view of the relevant interest groups. The result of this multi-dimensional evaluationrnprocedure of common heat sources and heat sinks for a reversible 10 kW H_2O/LiBr absorption heat pump isrnpresented. Primary energy use, system economics, market potential and comfort requirements have beenrnused as evaluation criteria with different weighting factors for users, producers, and governments.