Journal Articles
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Item Exergy analysis of a medium size LNG tanker steam power plant(Annual technical volume, Marine engineering division board, 2016) Sinha, Rajendra Prasad.; Balaji, Rajoo.Exergy is the maximum work which can be obtained from a quantity of heat Q at temperature T1 received by a system interfacing with a surrounding environment at temperature T0. In other words from the received heat energy ‘Q’ a small portion fails to convert into useful mechanical work and is thus lost which we call exergy destroyed. The loss of exergy in this heat work exchange process lowers overall thermal efficiency of the plant. Exergy destruction is actually the result of irreversibility in various processes of the plant and can be estimated from the second law of thermodynamics as the product of ambient temperature T0 and the positive entropy change Δsi.e. (T0Δs). The common irreversibility which cause entropy rise are mechanical or hydraulic friction, heat transfer with a finite temperature difference and diffusion with a high gradient of concentration etc., as most of these are present in a physical plant. Exergy analysis gives an insight into the way energy flows in the system and helps to locate components of the plant with high irreversibility to effect design improvements. In this paper the authors conduct energy and exergy analysis of 30 MW dual fuel fired marine steam power plant of a typical medium capacity LNG tanker and identify components responsible for major exergy destruction. Effects of steam reheating to reduce irreversibility and potential utilization of the cold energy of boil off gas in the thermodynamic cycle has been studied with the result showing 2-4 % improvement in the overall exergy efficiency of the plant.Item An analysis of shipboard waste heat availability for ballast water treatment(Journal of Marine Engineering & Technology, 2014-12) Balaji, Rajoo.; Yaakob, Omar.Heat treatment of ballast water is one of the many treatment options being explored. This analysis has tried to assess the heat availability from the cooling water, exhaust gases of the engines and steam condensers based on design and operational data obtained from an existing crude oil carrier. Time requirements for ballasting and treatment using the seawater and condenser circulating pumps are projected. Heat balance exercises were also carried out on a testbed engine to verify attainable heat recoveries. It is seen that, although considerable heat is available, a longer time than that available during ballasting and normal ballast passages will be required for the treatment process.Item A study of ballast water treatment using engine waste heat(Journal of The Institution of Engineers (India): Series C, 2019-04) Balaji, Rajoo.; Yaakob, Omar.; Koh, Kho King.; Adnan, Faizul Amri bin.; Ismail, Nasrudin bin.; Ahmad, Badruzzaman bin.; Ismail, Mohd Arif bin.Heat treatment of ballast water using engine waste heat can be an advantageous option complementing any proven technology. A treatment system was envisaged based on the ballast system of an existing, operational crude carrier. It was found that the available waste heat could raise the temperatures by 25 C and voyage time requirements were found to be considerable between 7 and 12 days to heat the high volumes of ballast water. Further, a heat recovery of 14–33% of input energies from exhaust gases was recorded while using a test rig arrangement representing a shipboard arrangement. With laboratory level tests at temperature ranges of around 55–75 C, almost complete species mortalities for representative phytoplankton, zooplankton and bacteria were observed while the time for exposure varied from 15 to 60 s. Based on the heat availability analyses for harvesting heat from the engine exhaust gases(vessel and test rig), heat exchanger designs were developed and optimized using Lagrangian method applying Bell–Delaware approaches. Heat exchanger designs were developed to suit test rig engines also. Based on these designs, heat exchanger and other equipment were procured and erected. The species’ mortalities were tested in this mini-scale arrangement resembling the shipboard arrangement. The mortalities realized were[95% with heat from jacket fresh water and exhaust gases alone. The viability of the system was thus validated.Item A review of developments in ballast water management(Environmental Reviews, 2014-03) Balaji, Rajoo.; Yaakob, Omar.; Koh, Kho King.Transportation and translocation of non-native species by ships through ballast water is one of the current issues the shipping industry is trying to address. The Ballast Water Convention is nearing full ratification after which treatment of ballast water will become mandatory for most of the trading merchant vessel categories. Ballast water management systems employing various technologies are commercially available but at high costs. Economics apart, the efficiency of these technologies and realistic ways to ensure compliance with stricter requirements of some Administrations are issues that need to be focussed upon. With the report of the Environmental Protection Agency as an assessment reference, this paper reviews the treatment technologies. Juxtaposing reports of Lloyd’s Register on the status, a concise overview of the technologies has been projected. A sustainable ballast water management based on data and assessments is proposed. The management must be extended to both shore and on-board platforms for practices, treatment, sampling, testing, and recycling. An exemplar system harvesting shipboard waste heat is projected as a route for thermal treatment in combination with technologies showing potential for optimized ballast water management