The work presented is an effort to realize the changes occurring for convective coefficients of heat transfer in STHX fitted with inclined baffles. Effort has been undertaken using Fluent, a commercially available CFD code ona CAD model of small STHX with inclined baffles with cold liquid flowing into the tubes and hot liquid flowing in the shell. Four sets of CFD analysis have been carried out. The hot liquid flow rate through shell compartments varied from 0.2 kg/sec to 0.8 kg/sec in steps of 0.2 kg/sec, while keeping the cold liquid flow condition in tube at 0.4 kg/sec constant. Heat transfer rates, compartment temperatures, and overall heat transfer coefficients, for cold liquid and hot liquid, were studied. The results given by the software using CFD approach were appreciable and comparatively in agreement with the results available by the experimental work, which was undertaken for the same set of inlet pressure conditions, liquid flow rates, and inlet temperatures of liquid for both hot and cold liquids. The experimental output results were also used to validate the results given by the CFD software. The results from the CFD analysis were further used to conclude the effect of baffle inclination on heat duty. The process thus followed also helped realize the effects of baffle inclination on convective heat transfer coefficient of the liquid flow through the shell in an inclined baffle shell and tube heat exchanger. The temperature plots for both cold and hot liquid were also generated for understanding the compartmental temperature distributions inclusive of the inlet and outlet compartments. The heat duty for a heat exchanger has been found to increase with the increase in baffle inclinations from zero degree to 20 degrees. Likewise, the convective heat transfer coefficients have also been found to increase with the increase in baffle inclinations.

Most of the researchers have claimed that high compression engines (diesel engines) are performing slightly above of 1/3rd of their potential and remaining heat energy is wasted in the form of exhaust gas. Efforts are going on to improve the design of these engines and investigations are being carried out to recover this waste energy from exhaust gases and utilize for different applications.In the present work, initially water is used as a heat exchange medium for three different loads on diesel engine viz., 50%, 60% and 70%, which extracts heat energy to evaluate the exhaust heat attainable from exhaust gases of the engine. The exhaust gas is passed through the tube side of the heat exchanger which is obtained from an exhaust manifold of a four stroke single cylinder diesel engine. Water is passed through the shell side of the shell and tube heat exchanger. Later this work is repeated for two different cooling medium i.e. water-ethylene glycol mixtures with 25% and 50%. The results are compared for 60% engine load conditions. The counter flow type heat exchanger arrangement is considered for the analysis. The temperatures were recorded for hot gases and cold medium at inlet and outlet points of the shell side and tube side flow. Heat calculations are carried out for each combination and detailed in the result–discussion and conclusion chapter. The objective of this work is to assess the exhaust gas heat recovery capacity using the ethylene glycol-water mixture and come out with a mixture for higher heat recovery capacity. This work is undertaken with segmental baffle heat exchanger of zero degree inclination. Also the work is repeated for inclined baffle heat exchangers of 10-degree and 20-degree baffle inclination to assess the effectiveness of liquid in recovering the heat from exhaust gases. It is observed that the water and Ethylene glycol mixtures have performed satisfactorily in all three baffle setups showing only 1.5% - 2.0% less heat recovery when compared with only water.

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The present work considers on convective coefficients of heat transfer for STHX for an inclined baffle. The work is undertaken using Flow Vision, a commercially available CFD code on a small STHX with inclined baffles having hot tube side liquid flow conditions and cold shell side liquid flow conditions. Four set of constant cold liquid flow conditions with 0.3kg/sec to 0.6 kg/sec are considered through shell compartments and a constant flow of 0.3 kg/sec for hot liquid is considered through the tubes. Heat transfer rate, overall heat transfer coefficients, pressure drops and temperatures at inlet and outlet nozzles on shell-side and tube side are studied. The results out of the work using CFD strategy is compared with the experimental work which is carried out for the same set of inlet temperatures, flow rates, and pressure conditions through shell compartments and tube side liquid flow. The CFD results are validated using the experimental output results. The validated results from the CFD analysis are compared with the theoretical results computed using the Bell-Delaware method for the same heat exchanger with zero-degree segmental baffles. The process carried out helps to realize the effects of baffle inclination on shell side convective heat transfer coefficient in a shell and tube heat exchanger. The temperature and velocity plots help to study the compartmental temperature, velocity and pressure distributions, including the inlet and outlet compartments.

The present work is embraced to study the cold fluid flow through the shell compartments and its pressure changes between shell inlet and shell outlet nozzle for an STHX which is implemented with an inclined baffle plate. The work focuses on pressure changes on shell side using Flow Vision, commercially available CFD software. A small