Investigating sustainable ways and means of enhancing the overall thermal efficiency of diesel power plants in Mauritius and Rodrigues Islands.
Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
During the past century the world has gone through the industrialization era where the focus was placed upon maximization of production at any cost to meet the world demand for basic needs as well as comfort. The law of supply and demand dictated the rules of the game while other factors like environmental preservation and the exhaustion of primary sources of energy were overlooked.
Such an uncontrolled exploitation of energy resources has led to the fast depletion of the world’s energy reserves (with a very negative impact on the ecosystem). This adapt or perish situation has given rise to a paradigm shift towards sustainability. The depletion of fossil fuel reserves has led to soaring price for this raw material as well as for all other petroleum derived products. Such a situation has paved the way to a new era where the focus has been shifted to the exploitation of other sources of energy capable of reconciling both renewability and sustainability aspects. It is however a matter of fact that the access to technologies and infrastructures enabling efficient exploitation of renewable energy sources (e.g. solar, wind, etc.) is limited on account of their intermittent nature, complexity, and high cost (i.e. not firm power requiring back up when not available). This stands as the main reason why to date only developed countries (with interconnected grids) like Germany, Denmark, etc. have succeeded in diversifying their primary energy mix in such a way to increase the share of renewable energy sources at the expense of conventional petroleum/coal based energy sources.
For small island states, the exploitation of renewable energy resources to cater for firm power constitutes a real challenge in the short term. Hence this project has for main objective to find ways and means to bring in sustainability in their actual energy conversion processes by achieving the optimized conversion efficiencies when delivering required energy supplies. . Several avenues leading to this goal were studied through literature review and their applications to two power plants (one from Mauritius Island and one from Rodrigues Island, namely Fort Victoria Power Station and Pointe Monnier Power Station respectively) were considered. A feasibility study was hence carried out based on technical and financial implications to ensure that the proposed changes are viable.
The findings of this study are multiple. The energy audit conducted revealed that only 38-44 % of the primary energy used in the power plants is converted into electrical energy implying that valuable heat energy can be recuperated for polygeneration processes. Considerable amount of energy is indeed lost in the medium and low temperature ranges. Recuperation of part of this energy is achievable through a combination of conversion processes including desalination, heat driven refrigeration, electric power generation through HRSGs, heat driven chilling and supplying process heat to industries through heat distribution network. The study indicated that at Fort Victoria the percentage of recoverable heat through HRSG/Steam turbine, heat driven refrigeration and air-conditioning is of the order of 16.5 %. For Pointe Monnier power station the conversion process can be enhanced by 7.28% in summer and 30.28 % in winter. This is due to the fact that on top of HRSG/Steam turbine and refrigeration, additional heat recoverable can be used either for air conditioning in summer or for desalination in winter.
It was also found that the above mentioned polygeneration processes are economically viable as the payback time is relatively short. This is due to the fact that the operational cost is on the low side as the energy required to drive the processes is free. The results obtained clearly indicate that it is worth investing in polygeneration as it will not only bring in sustainability but would also contribute towards minimizing harmful emissions while enhancing profitability of the power plants.
Place, publisher, year, edition, pages
2012. , 150 p.
power plants, diesel, thermal efficiency
Engineering and Technology
IdentifiersURN: urn:nbn:se:kth:diva-102707OAI: oai:DiVA.org:kth-102707DiVA: diva2:557759
Subject / course
2012-09-04, University of Mauritius, 12:16 (English)
Jayasuriya, JeevanSurroop, Dinesh, Doctor
Fransson, Torsten, Professor