Master Dissertations
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Item Design of plate fin heat exchanger with offset strip fins for the liquefaction of natural gases(Indian Maritime University, Kolkata Campus, 2019-06-20) Kashiwal, Mukul; Eswara, Arun KishoreIn the cryogenic systems such as liquefier, cryo-coolers, etc. the heat exchangers are one of the most critical components. The heat exchanger used in cryogenic applications must have high effectiveness to produce a proper refrigerating effect and it should not be less than 85%. It has already experimented that if the value of the effectiveness of the heat exchangers falls below the design value, then the no liquid will be produced. On a general basis, there are so many heat exchangers available in the industry which are used in the cryogenic works but there is a special category of the heat exchangers that are available, which are now used widely because of there because of their compactness, low weight, and high effectiveness. These heat exchangers are known as the compact heat exchangers. The objective of this work is to design a plate fin heat exchanger, which is when used in the liquefaction cycle must be able to liquefy the natural gases and to produce 1000 Kg liquid ih a day, which can be transported easily for the various purposes through various ways. This work has been carried on the plate fin heat exchanger with selecting the offset strip fin, which is the most reliable fin design in the liquefaction applications. The work includes the two cryogenic fluids, one is methane and the other is propane. Propane is used as the coolant to bring down the temperature of methane to this close that when passed through the expander or by precooling in the liquefaction cycle it gets liquefied easily. Catia software was used to model the component and Matlab programming has also been done to design a plate fin heat exchanger. As the geometry were too complex to analyse in the software because of the physical memory limitation, a small symmetric part of the heat exchanger model were imported in the analysis software called Ansys 18.1 for the validation of the results and it can be concluded from the observations that the model is capable to do the desired function. A small variation in the calculation and analysis results has been observed, and the effectiveness of the heat exchanger was found to be above 90 %. Aluminium 3003 has been used as the material for the fins strips and for separating plate.Item Design of small scale liquefaction cycle for natural gas(Indian Maritime University, Kolkata Campus, 2019-06-19) Gupta, Nishit; Eswara, Arun KishoreLiquefied natural gas is found to be the most economical mode of transportation for distances covering more than 3500 miles. The boiling point of natural gas is 111 .7 K at atmospheric pressure and falls under the category of cryogenics. The process has components such as compressor, heat exchanger, expansion valve, insulating material, storage tank and pipes. The liquefaction of natural gas is achieved by processing natural gas in the liquefaction cycle. There are many parameters affecting the cycle such as compressor efficiency, heat exchanger effectiveness, ambient temperature, friction losses in pipes and insulating materials. In this thesis, some of the above mentioned parameters are considered while some parameters are neglected or assumed appropriately. It is observed that out of the existing cycles such as simple Linde-Hampson cycle, Pre-cooled cycle, Claude cycle and Kapitza cycle, each cycle has its own benefits and drawbacks. The fraction of liquefaction is found maximum for simple Claude cycle while the work required also reduces due to expansion of the high pressure gas through reciprocating expansion engine. The iterative procedure to find the configuration of each cycle is explained in the thesis and can be used with minimum bare inputs. An experimental setup can be built through these configurations and better study can be performed. To obtain the results, residue in the iterations is taken to 0.1 for temperature, pressure and mass flow rate both. In the Claude cycle, for mass flow rate of 1.02 kg/sec and the pressure ratio of 40, the fraction of liquefaction is found 0.0646 while in the kapitza cycle, for mass flow rate of 1.35kg/sec and the pressure ratio of 40, the fraction of liquefaction is found as 0.040. It is found that, the pressure required to liquefy the gas is not practical in the case of Linde-Hampson cycle. Further, it is found that Claude and Kapitza cycle can be used for experimental purpose.Item Piping design for LNG liquefaction systems(Indian Maritime University, Kolkata Campus, 2019-06-20) Gupta, Satya VartLiquefied Natural gas is the future of the energy sector, as it is a source of clean energy. The liquefaction of natural gas is achieved at 111.67 K temperature, 1 atm; which is a cryogenic temperature. The cryogenic flow needs special attention because fluid, as well as material of the pipe, behave differently at cryogenic temperature. Two-phase flow is another critical point in the liquefaction of natural gas. The objective of this thesis work is to select the material of the pipe, calculate frictional losses in the pipe, and pressure drop in the pipe through which the cryogenic fluid flows. The frictional loss in the pipe mostly depends on Reynolds number, Roughness factor, and phase of flow. As the Reynolds number increases, the friction factor increases in a greater value. As the time lapses, corrosion and erosion factor plays a key role in frictional pressure drop. As there is an increment in pipe diameter, the pressure drop due to friction or frictional losses decrease but by virtue of that the weight of the piping system increases which is an unfavourable condition from an economic point of view. The flow in pipe encounters different forms of fluid in the liquefaction cycle of natural gas i.e. liquid phase flow, Gas phase flow and mix flow of liquid and gas. The Liquid flow and gas flow in a pipe are mainly deal with the Colebrook equation. Two-phase flow is a critical phenomenon in the liquefaction cycle. The pipe sizes mentioned in the result can be used for experimental setup. It is found that the corrosion factor is 0.3 and 3 mm respectively for a period of 30 years. Also, it is found that, there exists two phase flow after the joule Thomson expansion device. While selecting the pipe size, it has been observed that the thickness of the pipe greatly depend on internal pressure of the flowing fluid.Item Process improvement in shipbuilding by implementation of predictive maintenance within the shipbuilding 4.0 environment(Indian Maritime University, Kolkata Campus, 2019-06-19) Kumar, Rishi; Sinha, Sudhir KumarShipyards use a variety of machinery and equipment in the process of ship building. The equipment is complex and requires expertise in handling and maintenance. The productivity of the shipyard is closely related to effective use of these machinery and equipment. The shipbuilding productivity in India is not among the best in the world. There are many reasons behind the lesser productivity, one such factor was identified by me is in the inability of the shipbuilding industry in adopting the technological advancements quickly. Industrial Internet of Things (Industrial Internet of Things) is a latest philosophy that has shown to be having many advantages. This technical leap if implemented may be called a Shipbuilding 4.0. IIOT can help in will change the structure, fabricating, task, shipping, administrations, creation frameworks, support and esteem chains in the all parts of the shipbuilding business and effect of the Shipbuilding 4.0 will be huge in shipbuilding machinery maintenance as well. In this project I have proposed a model to improve the shipbuilding process by proposing a usage prototype for implementation of IIOT in the shipyard based on findings and analysis of the causes of mechanical failure in major shipbuilding machinery in the shipyard, followed by an audit of the present day scholarly and mechanical advancements.Item Ship recycling with a way to reduced hazardous effect on the environment(Indian Maritime University, Kolkata Campus, 2019-06-19) Gadgil, PratikShip recycling is a complex process of dismantling of the obsolete vessel, during this process a large amount of hazardous waste is produced which causes great environmental and health impact. To reduce this effect many laws and regulation are implemented but still there are cases of environmental impacts. This work is carried out to minimize the effect of hazardous material produced during ship dismantling. The data was collected from ship recycling yard of kolkata port trust. The list of quantity of hazardous material, average cost of disposal, average cost of transportation and storage cost is obtained. I consulted with maritime expert that is surveyors, ship recycling managers, chief engineers who suggested to use Analytic Hierarchy Process. Criteria in this process is based on expert suggestion and most preferred way for obsoleting vessel was found to be dry docking, Further based on data of quantity of hazardous material the preferred way of ship obsoleting was proposed. Further most hazardous material was calculated based on ship yard policy and it was found to be Asbestos and PCB. This method can be used in the industry as it give a whole view about best recycling method for green ship recycling, preferred method for vessel obsoleting based on inventory of hazardous material and also suggest potential hazard present in recycling yard based on ship recycling yard policy.null.listelement.badge Study on Impact of Covid-19 Pandemic on Shipping Business of Maersk(Indian Maritime University, Kochi Campus, 0022-05) Amalkrishna, P. A.; Yogamala, H. L.