CFD analysis of a tube-in-tube heat exchanger to recover waste heat for food drying

Abstract

Food waste is an alarming issue for the modern world. Drying is one of the oldest and easiest solutions for overcoming unnecessary food waste. However, most of the conventional drying consumes a significant amount of energy to remove water from food. On the other hand, there are many sources, which cause heat waste. Smart utilization of waste heat from sources including IC engine, turbine, brick kiln and something like those would be a great solution to the energy consumption problem of food drying. There is no systematic theoretical analysis of waste-heat-based food drying system available in the literature. In this study, a comprehensive transport model of drying system using engine’s exhaust waste heat has been simulated. Utilization of a small lab-scale IC engine exhaust results in reducing about 1137.15 kg of CO2 every year that would be produced from a conventional food dryer of the same capacity. In addition, low installation cost and payback period offer a promising rational solution of drying system. The proposed system is also capable of reducing entropy to an appreciable extent. Therefore, successful implementation of this proposed technique would offer a high-energy efficient, low-cost drying system along with ensuring a green environment.