Comparison of energy and exergy efficiencies of a sensible heat storage system for greenhouse heating


Ozturk H. , Bascetincelik A.

International Conference on Trends in Agricultural Engineering, PRAGUE, Czech Republic, 15 - 17 September 1999, pp.494-498 identifier

  • Publication Type: Conference Paper / Full Text
  • Volume:
  • City: PRAGUE
  • Country: Czech Republic
  • Page Numbers: pp.494-498

Abstract

In this research, solar energy was stored daily with the sensible heat technique for plastic tunnel greenhouse of 120 m(2). The system consists of mainly five units: external heat collection unit, packed bed heat storage unit, plastic tunnel greenhouse, heat transport unit and computer data acquisition/control unit. In the external heat collection unit 18 solar air heaters (total surface area of 27 m(2)) which have Raschig ring type of packing underneath the absorber plates were used. The packed bed heat storage unit (6 x 2 x 0.6 m deep) was designed under the greenhouse. In the heat storage unit, 6 480 kg of volcanic material was used as the heat storage material. Energy and exergy analysis were applied for evaluation of the system efficiency. The objectives of this study are to determine heat stored in the packed bed heat storage unit during the charging periods and to compare the energy and exergy efficiencies of the heat storage unit. It was determined that an average values of energetic and exergetic efficiencies for heat storage were 39.7 % and 2%, respectively.