Energetic performance analysis of a ground-source heat pump system with latent heat storage for a greenhouse heating

In this study, a ground-source heat pump heating system with a latent heat thermal storage tank was designed while its thermal energy storage performance was investigated. The heating system mainly consists of a ground heat exchanger, a heat pump, a cylindrical latent heat thermal storage tank, measuring units and a heating space of model-sized glass greenhouses with 30 m2, located in the greenhouse district of Fırat University, Elazığ, in Turkey. In the experiments, the performance characteristics of a ground-source heat pump greenhouse heating system with a 246 m horizontal 12.7 mm nominal diameter horizontal closed-loop ground heat exchanger and the use of phase change materials (PCM) for energy saving and management in greenhouses were investigated.The heating coefficient of performances of the ground-source heat pump (COPHP) and the overall system (COPsys) are obtained, to be in the range of 2.3–3.8 and 2–3.5 respectively. Although significant savings are possible with this heating system, a substantial investment in equipment and facilities may be required. The experiments results were obtained from October to May in heating seasons of 2005–2006. The results showed that the utilization of ground-source heat pump-PCM is suitable for greenhouse heating in this district.