Efficiency evaluation of a solar water heating system applied to the greenhouse climate

• Published in: Solar energy 2015-09, Vol.119, p.212-224
• Main Authors: Attar, I., Farhat, A.
• Format: Article
• Language: English
• Subjects: Climate; Economic greenhouse; Efficiency; Flat plate collector; Greenhouses; Ground solar heating system; Heating; Numerical analysis; Numerical simulation (Trnsys16); Simulation; Solar energy; Storage tank
• ISSN: 0038-092X; 1471-1257
• DOI: 10.1016/j.solener.2015.06.040

•Use of Trnsys16 to predict and improve a GSWHS rentability.•Experimental validation of simulation results.•Important effect of GSWHS to reduce the greenhouses heating cost. Tunisia has a sunny climate; therefore, the use of solar energy to heat greenhouses can be a solution to reduce the heating cost. A thermal model has been developed to investigate the potential of using a solar water system for greenhouse heating. This system is mainly based on capillary heat exchangers integrated in the greenhouse and ensuring the ground heat storing. A numerical study is conducted using Trnsys16 in order to estimate the exchanger length and the water flow rate allowing the best performance of the system. The inputs of Trnsys16 software were evaluated by experimental tests. The cost and the efficiency of the system were estimated for different greenhouses size. It was concluded that the heating cost of a 1000m3 greenhouse was reduced by 51.8% in April and the system can alone satisfy the heating needs for a 10m3 greenhouse. The good efficiency of the studied system was validated by an experimental study. The simulated and experimental results were compared and error did not exceed 6% which makes Trnsys16 simulation program an efficient tool to reproduce the real behavior of the ground solar water heating system.