Exergoeconomic Analysis and Multi-Objective Optimization of a Semi-Solar Greenhouse with Experimental Validation

Abstract Fossil fuels limitation and environmental pollution have justified using renewable energy resources. Utilization of the solar energy as a promising method to supply the heat required for a greenhouse with the aim of endurable agriculture has been an interesting subject for many researchers. In the present work, using MATLAB software, a dynamic model is developed to investigate an innovative semi-solar greenhouse from the thermodynamic and exergoeconomic viewpoints, which, to our knowledge, has not yet been performed for Iran conditions. This simulation is used to estimate the temperature in four different points of the semi-solar greenhouse, considering the crop evapotranspiration. In addition, the total exergy destruction values associated with different processes are inspected. Providing an appropriate thermal condition for the air inside was considered as the aim of the present study. In this regard, the air unit cost of the greenhouse for each time step is analyzed. A multi-objective optimization is conducted considering the total exergy destruction and mean air unit cost as the objective functions. To validate the simulation, the results of the proposed thermodynamic analysis are compared with the measured data recorded every one minute from the constructed typical semi-solar greenhouse. Temperature difference of 19.5 ℃ between the indoor and outdoor air is obtained during the experiment. The mean values of 6.08% and 2.1 ℃ for MAPE (Mean Absolute Percentage Error) and RMSE (Root Mean Squared Error) indicate the accuracy of the thermal simulation. The results show that using double-layer glass separated with air-filled space as the greenhouse cover decreases the overall exergy destruction about 45.36%. The multi-objective optimization results obtained from the Pareto frontier also shows total exergy destruction of 8.8623 MJ and mean air unit cost of 15.9164 $/MJ at the optimum point.