Evaluation of Dynamic Operation Effects for a Heat Pump in a Solar Combi-plus System
Abstract
Real-like –dynamic- working conditions shall be taken into account in the assessment of the seasonal performance of thermal system, particularly when these are driven by renewable energy sources. A vapour compression reversible heat pump installed in a solar combi-plus system was studied to verify the influence of variable sources and loads on the overall performance. The machine was tested in laboratory, following a dynamic sequence, which reproduces the seasonal real-like boundary conditions. The results of the dynamic test highlight the non-negligible influence of dynamic working conditions on the seasonal performance of the heat pump. Two unfavourable factors were identified, i.e. the presence of many on-off cycles during cooling mode and fast variations of the boundary condition – i.e. changing of set points in switching the operation from space heating to domestic hot water preparation. Given the importance of correctly evaluating these aspects, a short dynamic test procedure was developed and validated. This allows the evaluation of the seasonal performance of the heat pump, as far as the frequency distribution of the machine performance.
Keywords
Dynamic test, Compression heat pump, Seasonal performance, Solar combi-plus systems