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Nanoparticles enhances the heat transfer between particles and the fluids due to their high specific surface area and adjustable properties, including thermal conductivity and surface wettability, by varying particle volume concentrations in the base fluid to suit different applications. This article is an experimental study on the effectiveness and overall heat transfer coefficient in STHE (shell and tube heat exchanger), comprising baffle cut 25% with a nanofluid at 0.05, 0.1, and 0.2 percentage concentrations of CuO nanoparticles in the DW (distilled water) base-fluid. The inclusion of 0.15% SDBS (Sodium dodecyl-benzene sulphonate) by a two-step method as a surfactant improves the stability of dispersed CuO nanoparticles. The CuO/DW nanofluid thermo-physical properties such as thermal conductivity (k), density (ρ), and dynamic viscosity (μ), have increased. However, the nanofluid's specific heat (Cp) reduces as the nanoparticles proportion rises in the DW base fluid. There is an enhancement of the overall heat transfer coefficient and effectiveness compared to water during parallel flow variation. The maximum heat exchanger effectiveness was 3.01%, 4.01%, and 5.94% higher than water at 0.6 lpm mass flow rate and temperature T = 80 °C for volume fractions of 0.05, 0.1, and 0.2 percentage of CuO/DW nanofluid respectively during parallel flow.

The project work addresses development of a Domestic puffed rice making device hygienically. The reason for this development has arisen because of unhygienic way of preparing puffed rice, exposes the workers to health hazards due environmental effects and temperature effect in mass production facility. The critical parameter in the product design is related to the temperature operated with; which also influences the quality of puff with right crispiness. Salt is used instead of sand which provides the same quality of hygienic puffed rice. The product efficiency is quantified by the puffed volume, will be enhanced due to consistency in the temperature. The device is being designed keeping in mind the following parameters-• Hygienic and healthy • Domestic Usability • Ease of operation • Cost effective • Efficiency

Nanoparticles attracted many researchers because of their significant heat transfer enhancement properties in various applications. The nanoparticles have variable properties and a high specific surface (Cp) area, which enhance heat exchange between fluids and their particles at different volume concentrations. This article provides the outcomes of an experimental study on the overall heat transfer coefficient (Uo) and effectiveness ( ε) of the shell and tube heat exchanger (STHE) with a 25% baffle cut using Al2O3 nanofluid consisting of base fluid distilled water (DW) and Al2O3 nanoparticles at 0.05%, 0.1%, and 0.2% of volume concentrations. Using a two-step method and adding a weight fraction of 0.1% sodium dodecylbenzene sulfonate (SDBS) as a surface active agent to each volume concentration of nanofluid provides better stability. The thermophysical properties like density (ρ), thermal conductivity (k), and dynamic viscosity ( μ) of the Al2O3-DW nanofluid increased, but Cp of the same was reduced by increasing the volume fraction. Al2O3-DW nanofluid at different concentrations in parallel and counter flow variations of the STHE enhances the Uo and ε when compared with water. However, counterflow provides higher effectiveness. At 0.6 LPM of the nanofluid flow and hot fluid at T = 80°C temperature, the difference in the heat exchanger's effectiveness enhancement is 4.24% for parallel flow and 4.16% for counterflow at 0.2% concentration of Al2O3-DW nanofluid compared to water.

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