HEAT TRANSFER

This project study presents the design and simulation of a solar water heater utilizing Fresnel reflectors to concentrate solar radiation. The system employs the principle of Concentrated Solar Power (CSP) to heat water for domestic use. The Fresnel reflector focuses sunlight onto a receiver tube, increasing the temperature of the water. The heated water is then stored in a tank for use. The system's performance was evaluated using a mathematical model that takes into account the solar irradiance, concentration ratio, and heat transfer fluid's properties. The results show that the system can generate up to 2.5 kW of thermal power, with an efficiency of 55%. The system's performance was also experimentally validated, showing good agreement with the theoretical results With the generated power, this system can provide enough hot water for: - A household of 4-6 people - A small restaurant or café - A guesthouse or small hotel - A small industrial process requiring hot water This study demonstrates the feasibility of using Fresnel reflectors in solar water heaters, offering a cost-effective and environmentally friendly solution for water heating applications

Heat exchangers are fundamental components in thermal engineering, enabling efficient transfer of heat between fluids across various phase states. Their performance largely depends on the thermal characteristics of the working fluid, and improving these characteristics remains a central research focus. Nanofluids—base fluids enhanced with suspended nanoparticles—have emerged as promising candidates due to their potential to significantly improve heat transfer rates. This study investigates the viability of nanofluids as enhanced working fluids for heat exchanger applications, addressing the persistent challenge of increasing heat transfer efficiency in thermal systems. The methodology involved selecting a shell-and-tube heat exchanger and performing detailed mathematical modelling, numerical simulations, and comparative analyses. Simulations were conducted using ANSYS Fluent, supported by theoretical models such as the Maxwell-Garnett relations, Pak and Cho density formulation, and Brinkman viscosity correlations. Mesh generation, boundary condition setup, and performance evaluation were carried out systematically between July and November 2025. Various nanofluid types and volume fractions were iteratively tested to identify the most thermally efficient fluid configuration for the system. The results demonstrate a clear improvement in heat transfer characteristics when nanofluids are employed compared to conventional fluids. Significant enhancements were observed in thermal conductivity, convective heat transfer coefficients, and reduction in hot-air exit temperatures from the heat exchanger. The comparative outcomes confirm the strong potential of nanofluids to boost thermal energy recovery and overall system performance, highlighting their suitability for advanced industrial heat exchanger applications.

Heat exchangers are fundamental components in thermal engineering, enabling efficient transfer of heat between fluids across various phase states. Their performance largely depends on the thermal characteristics of the working fluid, and improving these characteristics remains a central research focus. Nanofluids—base fluids enhanced with suspended nanoparticles—have emerged as promising candidates due to their potential to significantly improve heat transfer rates. This study investigates the viability of nanofluids as enhanced working fluids for heat exchanger applications, addressing the persistent challenge of increasing heat transfer efficiency in thermal systems. The methodology involved selecting a shell-and-tube heat exchanger and performing detailed mathematical modelling, numerical simulations, and comparative analyses. Simulations were conducted using ANSYS Fluent, supported by theoretical models such as the Maxwell-Garnett relations, Pak and Cho density formulation, and Brinkman viscosity correlations. Mesh generation, boundary condition setup, and performance evaluation were carried out systematically between July and November 2025. Various nanofluid types and volume fractions were iteratively tested to identify the most thermally efficient fluid configuration for the system.

The research examines how affordable teaching materials affect students' understanding of heat transfer at the University of Benin. Two research questions and two hypotheses were developed and answered to guide the study. A quasi-experimental survey design was utilized, with 50 participants selected purposefully from the Health, Safety, and Environmental Education (HSE) department, specifically 100 level students. A structured questionnaire created by the researcher was used to collect data, which was then analyzed using mean, standard deviation and frequency counts for descriptive purposes. The findings indicate that inexpensive teaching materials have a significant impact on both teaching and learning processes, as well as on the long-term retention of environmental education knowledge when implemented in instruction.