SOLAR ENERGY UTILISATION FOR PROVIDING AND MAINTAINING OPTIMAL MICROCLIMATIC CONDITIONS OF GREENHOUSE CUCUMBER. PART I: THERMAL PERFORMANCE ANALYSIS OF SOLAR WATER HEATER

Document Type : Original Article

Authors

1 Prof. and Head of Agric. Eng. Dept., Fac. of Agric., Mansoura Univ., Egypt.

2 Associate Prof., Agric. Eng. Dept., Fac. of Agric., Mansoura Univ., Egypt.

3 Demonstrator, Agric. Eng. Dept., Fac. of Agric., Mansoura Univ., Egypt.

Abstract

The main goal of the present study was to predict water temperature in the storage tank at the end of each day during winter season of 2007-2008. A complete solar heating system (solar collector and storage tank) was utilised for heating 400 litres of water. A mathematical computer model was developed to determine the thermal performance analysis of the solar heating system. Temperatures of outside air, water in the storage tank, and inlet and outlet water of the solar collector were measured and recorded on a data-logger to analysis their correlation with the water temperature prediction model in order to control solar energy heating in agricultural applications. The obtained data showed that, the daily average solar energy available was 13.372 kWh/day of which 7.138 kWh/day was stored in the storage tank of the solar energy system. The daily average overall thermal efficiencies of the solar collector and the storage system during the experimental period were 72.07% and 74.18%, respectively. They varied from day to another and during each month according to the solar energy available, the water temperature in the storage tank at the beginning of each day, and the ambient air temperature. The obtained results also revealed that, the predicted water temperatures were validated well with that measured during the experimental period by 94.68%, which gave an excellent agreement. 

Main Subjects


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