Performance analysis and optimisation of box type heat exchangers used in ships

Heat transfer is an event that occurs every moment of life. Human body or itscomponents like lungs or skin are all organic heat exchangers. Most basic question ofindustry for this kind of most freqently used items is a way to design a smallerexchangers for the same amount of heat transfer. This study is prepared andpresented in order to find an optimum area for a kind of heat exchanger used in shipsand compare this system with its alternatives in way of dimensions, thermodynamicaland economical performances.Initially, types of heat exchangers are mentioned. Classification of heat exchangersaccording to their way and mechanism of heat exchange, compactness, no of fluid,constructions and flow types are explained by supporting diagrams and graphs withtheir basic and most common properties, points to consider during fabrication andusage of these items and utilization areas.After referring types of heat exchangers using in ships with their aim of usage, boxcoolers working principles, performances under icy or shallow water conditions,comparisons with other cooling systems and advantages, usages, and thermodynamicand constructive design principles are defined intensely.Optimum heat transfer areas both for a box cooler and a shell and pipe heat exchangerare determined in order to make comparison in way of their heat exchangingperformance in service of the same ship, by using a mathematical modelfundemantally based upon a NTU method. Parameters effecting the optimum heattransfer area are examined by this mathematical model. Graphics and diagrams arecreated in order to observe these parameters and their rate of effects reflected oneach parameters take role in the main function.For economical comparing, a cooling circuit is prepared for cooling the main engines ofthe same ship with two engines, both via box coolers and shell and tube heatexchangers. Necessary equipments for these two cooling circuits are listed and theirinvestment costs, operation and maintenance costs are calculated.A series of acceptances, equations and formulas, calculations, mathematic method andreceived thermodynamic and economic results are given respectively for designers andusers of this kind of cooling systems.