Design and Modelling of a Solar Water Heating System

摘要

The demand for energy in Nigeria is usually met by burning fossil fuels such as charcoal, petroleum, natural gas, kerosene, etc. or by the use of electricity. These conventional energy sources are exhaustible, unstable and not environmentally friendly. Electricity generation in Nigeria is not sufficient enough to meet the demand for energy. This has often been blamed on lack of technical know-how, excess profiteering by marketers and large population size of the citizens. The seemingly alternative to these is burning of firewood. This however has its negative effects as exploitation of firewood will cause deforestation leading to desert formation in the country. Solar energy therefore appears to be the only veritable and viable alternative source of energy to heat water. It is inexhaustible, has no effect on the environment, and can be converted to many other forms of energy. Converting it to thermal energy in order to heat water is done with a solar water heating system. This work explores the use of solar energy to fulfil the hot water requirements in Nigeria and creates a model for the water heating system. Through modelling, the efficiency of the system and major factors affecting the system are determined. This project seeks to model a thermo-syphon system, which relates the effect of efficiency and also a gross area of the solar collector on the volumetric flow, from experimental results in Akure, Nigeria. Thermo-syphon systems, being the most suitable for the climate of Nigeria, were evaluated and analysed. The result of the analysis shows that if the efficiency of the system is increased, the area is increased resulting in an increase in the volumetric flow, which can be used to evaluate the amount of water being heated per time.