Modeling and simulation of an active solar water heating system for Maiduguri, Borno State, Nigeria

Abstract

The recent interests in renewable energy throughout the world has created a need for research in the area of solar technology, specially solar water heating system. A numerical experimental investigation was conducted to develop a model of an active solar water heating system to produce domestic hot water at 90oC using Typical meteorogical year (TMY 2) solar weather condition data of Maiduguri. The numerical experiment was used for simulation and TRNSYS 16 software was also used to determine the hourly thermal performance of the model. The main component of the TRNSYS deck file constructed for this purpose is Type 109, accompanied by other components require for the model. TMY 2 weather data of Maiduguri was processed to obtain the monthly average daily hot water for Maiduguri, and the recommended average day of each months were also used. The weather condition of the month of August was considered for the design. The result of simulation shows that an active solar system collector area of 2.04m2 with inlet flow rate of 120kg/hour for hot water application, tilted at an angle of 12o to the horizontal would be capable of producing daily domestic hot water of 0.1m3 volume to the desired temperature of 90o C. The validation computed by using statistical tool of Nash-Sutcliffe Coefficient Efficiency (NSE) and Root Mean Square Error (RMSE) reveal the system ambient temperature and storage tank temperature of 1.60C,0.82 and 3.60C,0.96 respectively. For the experiment conducted, the model has capacity of predicting the performance of system with 82% and 96% degree of accuracy for that the experiment conducted. The early hours of each months as compared by the collectors showed that the serpentine solar collector has higher thermal performance than the riser-header flat plate collector but after 15:00 hours, Riser-header solar collector performance is better. This means that that riser-header solar collector has higher performance better than serpentine solar collector.