Journal Articles

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Author: search.filters.author.Yaakob, Omar.Has files: Yes

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    Validation of engine performance for tests on ballast water heat treatment using engine waste heat
    (International Journal of Marine Engineering Innovation and Research, 2017-12) Balaji, Rajoo.; Yaakob, Omar.; Koh, Kho King.; Adnan, Faizul Amri bin.; Ismail, Nasrudin bin.; Ahmad, Badruzzaman bin.; Ismail, Mohd Arif bin.
    Heat treatment has been considered as a suitable option for treatment of ballast water. Utilising the waste heat from the diesel engine fresh water and exhaust gases would be an economic option. For recovering the heat from the exhaust gases, heat exchangers are required to be placed in their flow path. The sea water coolant after recovering heat from fresh water has to be directed to this heat exchanger for sterilisation. For testing the effectiveness of these heat recoveries on species’ mortalities, a mini-scale system was arranged and tests were carried out. The engine output and other flow rates were maintained to achieve a temperature range of 55 to 80oC. Data was obtained from the sensors and probes fitted at relevant points. The engine performance was monitored with computerised control equipment. Operational data from five test runs were analysed and verified by two approaches. In the first approach, the heat recovered by the water was compared with the heat lost by the exhaust gases and the maximum variation was observed to be 3.4%. In the second approach, the input energies were computed using two different methods using data values of brake power, thermal efficiency, mass flows, calorific value and specific fuel consumption. A maximum variation of -11% was seen for only one test run, while for other tests the variation was between -0.7% to -1.7%. The values obtained from the connected probes and the computed results were thus validated and further tests on species were carried out.
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    Optimisation of a waste heat exchanger for ballast water treatment
    (Scientia Iranica B, 2015) Balaji, Rajoo.; Yaakob, Omar.
    Ballast Water Treatment systems, which are type approved and commercially available, require improvements to meet stricter standards, and heat treatment could be a viable additional option. Considering the waste heat potential on a ship, a system harvesting the engine exhaust heat may be envisaged for which a heat exchanger could be vital. Design optimisation of a heater, employing the exhaust gases of an engine as utility fluid, and ballast sea water as the process fluid, was achieved using Lagrangian methods, keeping the annual cost as the objective function. Limiting the number of variables, optimal values were calculated with cost considerations for utility fluid and also pumping costs for utility and process fluids. In all, four optimum designs and three comparative designs were developed. Heat balance data from an operational tanker, specific fuel consumption values and fuel costs were considered for the design. The thermodynamic and geometric designs were worked out using computer based software for a comparison. Designs were compared on the basis of annual cost, optimum exit temperature of shell side fluid, optimum mass flow of tube side fluid and heat exchanger e ectiveness. It is demonstrated that an optimal heat exchanger design can be obtained with simple optimisation procedures.
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    Emerging ballast water treatment technologies: a review
    (Journal of Sustainability Science and Management, 2011-06) Balaji, Rajoo.; Yaakob, Omar.
    Ballast water-shifts across the globe have been a major cause of ecological imbalance. The International Maritime Organisation (IMO) has actively taken regulated measures to minimise the species shift by adopting the International convention for the Control and Management of Ships’ Ballast Water and Sediments in 2004. Since then, vessels have been increasingly practising water exchanges. Exchanges are seen to be not completely effective. This regime has to give way for effective Ballast Water Treatment to keep up with IMO requirements as also the stricter requirements stipulated by some US ports. As full ratiication of the Treaty is pending, many treatment technologies have been emerging. A review of some representative systems is presented in this paper. Brief analyses of the systems available on date and those awaiting approval have been carried out. Most of these systems use a pre-treatment employing physical iltration and in the later part treat the ballast water with physical and chemical disinfection methods. An effective method for species reduction has been to employ chemicals. In terms of capital cost, foot print and power requirements, chemical solutions fare better than the physical disinfection methods. However, it is feared that chemicals might cause greater harm to the environment. Physical disinfection methods have lesser issues than the usage of chemicals. Considering the long-term harm of chemicals, a iltration system in combination with heat treatment is suggested. Such an attempt might even emerge as a viable option before the IMO deadline of 2016.
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    Design verification of heat exchanger for ballast water treatment
    (Jurnal Teknologi, 2014) Balaji, Rajoo.; Yaakob, Omar.; Adnan, Faizul Amri bin.; Koh, Kho King.
    Using waste heat from ship’s engines is one of the methods considered for heat treatment of ballast water. For such a system harvesting the engine exhaust heat, a heat exchanger will be vital. Design optimisation of a heater employing exhaust gases of the engine as utility fluid and ballast sea water as the process fluid was achieved using Lagrangian methods, keeping the annual cost as the objective function. Costs for installation, maintenance as also costs for the utility and process fluids were considered. Heat balance data, specific fuel consumption values from a typical operational ship and current fuel costs were considered for the design. The thermodynamic and geometric designs were worked out using computer based software for comparing the designs. Costs were also computed using a different approach for all the designs. Since the amount of heat transferred was specified and the application was limited to a single process, direct cost method was used for the computation. The objective function values obtained from Lagrangian equations were compared with the values obtained from direct cost computations. From the optimal designs, choice was justified based on annual cost, optimum exit temperature of shell side fluid and optimum mass flow of tube side fluid.
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    Comparision of heat exchanger design for ship ballast water heat treatment system
    (Jurnal Teknologi, 2015-10) Balaji, Rajoo.; Yaakob, Omar.; Koh, Kho King.; Adnan, Faizul Amri bin.; Ismail, Nasrudin bin.; Ahmad, Badruzzaman bin.; Ismail, Mohd Arif bin.; Vern, Yiow Ru.
    Sterilisation by heat can be a capital treatment for ballast water and waste heat from ship’s engines will be a good resource. Based on the waste heat availability on an operational tanker, a ballast water treatment system was envisaged including a shipboard heat exchanger for waste heat recovery. To verify the heat availability and the species’ mortalities, test rigs were arranged similar to shipboard arrangement. For assessing the smaller heat exchangers for the tests, designs were developed using Bell-Delaware approaches based on the shipboard heat exchanger design. The thermodynamic and geometric values were computed and the features of the commercially available and fitted heat exchangers were compared with the developed designs. Two commercially procured heat exchangers fitted on two separate engine test rigs were used for tests. The designs of commercially procured heat exchangers were close to the developed designs and were found to be suitable for the tests planned.
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    Ballast water management triad: administration, ship owner and the seafarer
    (International Journal of Environmental, Ecological, Geological and Mining Engineering, 2014) Balaji, Rajoo.; Yaakob, Omar.
    The Ballast Water Convention requires less than 5% of the world tonnage for ratification. Consequently, ships will have to comply with the requirements. Compliance evaluation and enforcement will become mandatory. Ship owners have to invest in treatment systems and shipboard personnel have to operate them and ensure compliance. The monitoring and enforcement will be the responsibilities of the Administrations. Herein, a review of the current status of the Ballast Water Management and the issues faced by these are projected. Issues range from efficacy and economics of the treatment systems to sampling and testing. Health issues of chemical systems, paucity of data for decision support etc., are other issues. It is emphasized that management of ballast water must be extended to ashore and sustainable solutions must be researched upon. An exemplar treatment system based on ship’s waste heat is also suggested.
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    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.
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    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.
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    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