Abstract
M.Tech. (Mechanical Engineering)
In South African rural communities rivers and rain water storage tanks are the main source of cooking, drinking and agricultural water. From 2015 to date, South Africa has experienced severe water shortages due to the worst droughts the country has faced in over 23 years. These droughts have led to the drying up of rivers and rain water storage tanks, as a result the livelihood of rural communities in South Africa is negatively affected.
An alternative water supply solution is needed for drought relief in South African rural communities. This study investigates the implementation of atmospheric water generator (AWG) technology for rural household use as a supplementary water source in the event of a water crisis.
In this study data is obtained from various existing weather statistics, review of existing literature, and compounded with data obtained using a computational simulation approach. The east coastal region of KwaZulu-Natal, situated between the cities of St. Lucia and Durban, was chosen as the case study location due to the favourable climate conditions for the implementation of AWG technology as well as the large number of surrounding rural communities that have been affected by the on-going droughts.
Comprehensive literature review was conducted on the historic weather patterns in the case study location, the climate change conditions which cause droughts, the existing AWG solutions on the market and the operating philosophy of AWG systems. A conceptual AWG model was developed from criteria defined in the literature review as well as first principal design calculations which established the design parameters. The conceptual design was detailed into a three dimensional computational model. Computational fluid dynamics (CFD) simulations were conducted on the computational model to predict the performance characteristics of the system. The results obtained from the CFD simulations as well as the findings from the literature review were used to answer the research questions presented in this study.
This study found that at the mean climate conditions of the case study location the AWG model can produce water at a competitive operational cost for emergency drought relief. The initial capital cost of the model however was found to be excessively high and resulted in the overall solution being uneconomical for rural households. The development of a cooling condensation type AWG system and its analysis forms the focus of this study.