DESIGN OF A COMPACT, COST-EFFECTIVE SHELL AND TUBE HEAT EXCHANGER WITH IMPROVED EFFICIENCY

Abstract

Heat exchangers were widely used in industrial applications but continued to face persistent challenges related to high fabrication costs, large size, fouling, and limited thermal efficiency. Conventional shell and tube heat exchangers, although robust and suitable for high-pressure and high-temperature environments, often required expensive materials and complex manufacturing processes, while design modifications typically resulted in trade-offs between performance and hydraulic resistance. Addressing these limitations was essential for enhancing energy efficiency, reducing operational costs, and promoting more compact, cost-effective designs suitable for small- and medium-scale industries. The present study aimed to design, fabricate, and evaluate a compact, low-cost shell and tube heat exchanger with structural improvements to increase efficiency. The exchanger was constructed from mild steel with spiral baffles and tested using chilled water as the cold stream and hot water as the heating medium. Thermocouples, pressure gauges, and flow meters were employed to record inlet and outlet temperatures, pressure drops, and flow rates, while thermal performance was analyzed using heat transfer rate (Q), log mean temperature difference (LMTD), overall heat transfer coefficient (U), and effectiveness (ε). Statistical reliability was ensured by triplicate measurements and mean value analysis. Results showed that the inclusion of a spiral rod significantly improved turbulence, leading to higher heat transfer efficiency (62.4% with spiral rod vs. 42.7% without; p < 0.05), and increased the heat transfer rate from 7.44 kW to 16.1 kW despite similar flow regimes. The compact exchanger achieved a performance comparable to larger industrial designs while maintaining a surface area of only 2.17 m² and a material cost of 56,000 units. In conclusion, the study demonstrated that spiral-rod integration effectively enhanced thermal performance, offering a feasible pathway toward more efficient, affordable, and sustainable shell and tube heat exchanger technology.