Faculty Publications
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Item Studies on esters of coconut oil as fuel for LPG-Biodiesel dual fuel engine(American Society of Mechanical Engineers Three Park Avenue New York NY 10016-5990, 2003) Kapilan, N.; Reddy, R.P.; Mohanan, P.The rapid depletion in world petroleum reserves and uncertainty in petroleum supply due to political and economical reasons, as well as, the sharp escalation in the petroleum prices, have stimulated the search for alternatives to petroleum based fuels specially diesel and gasoline. Biodiesel is one of the renewable fuels, which will be the good replacement to diesel. But as a sole fuel, it gives poor performance and higher emissions. From the literature survey, it is observed that not much work has been done to use Methyl Ester (ME) of coconut oil as liquid fuel in sole and dual fuel mode of operation. Hence, in the present work, ME of coconut oil is chosen as a sole fuel to run the diesel engine and an alternative pilot fuel to run LPG-Biodiesel dual fuel engine. In dual fuel mode operation, LPG is used as the inducted gaseous fuel. LPG has been chosen as the inducted fuel on account of its easy availability in abundance in the present time. The existing compression ignition diesel engine was modified to work on dual fuel mode. Tests were carried out on a single cylinder, four strokes, water-cooled, direct injection, compression ignition engine using ME of coconut oil as fuel. To study the effect of injection timing, its is advanced and retarded from the standard injection timing recommended for diesel operation. From the results, it is observed that the advanced injection timing results in better performance and lower emissions of the diesel engine. In dual fuel mode operation, first the engine was started with ME of coconut oil as fuel and then the LPG flow rate was increased. With appropriate proportions of the injected (0.45, 0.65 and 0.75 kg/hr) and inducted fuels it is possible to improve the engine performance and reduce its emissions. From the experimental results, it is found that the pilot fuel rate of 0.65 kg/hr is preferred from the point view of brake thermal efficiency, fuel consumption and smooth running. ME of coconut oil were successfully used as sole fuel and pilot fuel. The performance and emission of the engine in sole fuel mode with better injection timing and dual fuel mode with better pilot quantity were compared. From the comparison, it is observed that the ME of coconut oil can be used as pilot fuel in dual fuel engine compared to sole fuel with regard to performance and emissions.Item A comprehensive review on evaporative cooling systems(Elsevier B.V., 2023) Kapilan, N.; Isloor, A.M.; Karinka, S.The evaporative cooling system (ECS) is one of the cheapest and oldest cooling technologies. The conventional single stage ECS is most widely used in domestic application, particularly in hot and dry regions. However, in this system, the temperature of the air cannot be reduced below the wet bulb temperature of the air. The multistage ECS system helps to overcome this problem. The combination of direct and indirect ECS helps to reduce the temperature of the air below its wet bulb temperature. The further reduction in air temperature may be achieved with the help of the cooling coil driven by vapour compression system. The energy consumed by the ECS is lower as compared to vapour compression refrigeration system. The ECS can be driven with the help of solar power. The conventional cooling pad used in ECS can be replaced with locally available natural fibers to reduce initial cost and to reduce dependence on import of cooling pads. The performance of the ECS can be improved with the help of heat pipe. Various techniques are used to enhance ECS's performance. The performance of the vapour compression refrigeration system can be improved with the help of ECS. This paper discusses basics and types of ECS, methods used to increase the performance of ECS, types of natural fiber cooling pad material, process variables affecting ECS, recent technical advancements, challenges and opportunities. © 2023 The AuthorsItem Experimental investigation of esters of mahua oil as an alternative fuel for dual fuel engine(2008) Reddy, P.B.; Kapilan, N.; Reddy, R.P.In the present work, an attempt was made to use methyl ester of mahua oil (MEMO) as substitute for dieselin dual fuel engine. A four stroke single cylinder engine was modified to work in dual fuel mode. From the test results, it was observed that the MEMO could be used as pilot fuel in dual fuel engine. At lower loads, diesel gave higher brake thermal efficiency. But at higher loads, biodiesel resulted in brake thermal efficiency comparable with diesel and lower smoke and oxides of nitrogen emissions. From the test results, it was concluded that MEMO could be used as a substitute for diesel in dual fuel engine.Item Effect of using Mahua as an alternative fuel in diesel engine(2009) Kapilan, N.; Ashok Babu, T.P.A.; Reddy, R.P.There is an increasing interest in India, to search for suitable alternative fuels that are environment friendly. This led to the choice of non-edible Mahua Oil (MO) as one of the main alternative fuels to diesel oil in India. The objective of the present work is to use MO as a partial renewable alternative substitute for diesel in the agricultural diesel engine. Since the viscosity of the MO is high, it was blended with conventional diesel oil in various proportions (M5, M10, M15 and M20 on volume basis) and fuel properties of the blends were determined and compared with the diesel. Engine tests were carried out on a single cylinder diesel engine at varying loads (0%, 25%, 50%, 75% and 100%), without making any modification in the fuel injection system and the results were compared with the diesel. The M5 and M10 blends resulted in performance and emission characteristics comparable to diesel operation and also emits lower carbon monoxide, hydrocarbon and smoke emissions as compared to other blends. From the analysis, it is concluded that the MO can be partially substituted for diesel oil in the diesel engine, without making any modification in the hardware of the engine.Item Improvement of performance of dual fuel engine operated at part load(Universiti Malaysia Pahang editor.ijame@gmail.com, 2010) Kapilan, N.; Ashok Babu, T.P.; Reddy, R.P.Rising petroleum prices, an increasing threat to the environment from exhaust emissions, global warming and the threat of supply instabilities has led to the choice of inedible Mahua oil (MO) as one of the main alternative fuels to diesel oil in India. In the present work, MO was converted into biodiesel by transesterification using methanol and sodium hydroxide. The cost of Mahua oil biodiesel (MOB) is higher than diesel. Hence liquefied petroleum gas (LPG), which is one of the cheapest gaseous fuels available in India, was fumigated along with the air to reduce the operating cost and to reduce emissions. The dual fuel engine resulted in lower efficiency and higher emissions at part load. Hence in the present work, the injection time was varied and the performance of the dual fuel engine was studied. From the engine tests, it is observed that an advanced injection time results in higher efficiency and lower emissions. Hence, advancing the injection timing is one of the ways of increasing the efficiency of LPG+MOB dual fuel engine operated at part load. © Universiti Malaysia Pahang.Item Influence of diethyl ether on the performance and emissions of a compression ignition engine fuelled with biodiesel(Penerbit Akademia Baru, 2020) Kapilan, N.; Prabhu S, S.; Vasudeva, M.India is one of the major importers of petroleum products and hence government of India has taken several steps to find suitable alternative fuels to the fossil fuels. The biodiesel derived from non-edible oils is considered as an immediate substitute for the fossil diesel. In this work, biodiesel was produced from non-edible honge oil and used as substitute for the diesel. The engine tests were carried out on a diesel engine which is most widely used for agricultural purpose. From the engine tests, we observed that the diesel engine performance with biodiesel is lower than the diesel due to lower volatility and slightly higher viscosity of the biodiesel. Hence, the objective of this work is to study the impact of diethyl ether (DEE) on the performance of the engine. The engine tests were conducted on a single cylinder, water cooled, compression ignition engine at steady state condition. The engine test results showed an increase in brake thermal efficiency and reduction in engine exhaust emissions such as CO, HC and smoke with the addition of DEE as an additive. From this work we conclude that the DEE can be used as an ignition improver for the honge oil biodiesel. © 2020 PENERBIT AKADEMIA BARU - All rights reserved.