Design and analysis of energy and exergy performance of an LPG-powered fish drying machine

Abstract

A detailed design and analysis of the energy and exergy performance of a Liquefied Petroleum Gas (LPG)-powered fish drying machine are presented in this paper. The system designed is a modification to the conventional fish dryer which uses charcoal, electric or solar energy as sources of heat. The major problems of the conventional machines are; dangers of global warming from the burning of charcoals. The emission of smoke during operation causes environmental pollution which could have adverse effects on our respiratory systems. Moreover, it is difficult to attain uniform heat distribution using charcoal as a source of heat; erratic power supply in developing countries using electricity and inadequate sunshine using solar energy are all major problems of the conventional dryer. The gas-powered fish dryer is a fish processing device, which uses natural gas as the source of heat energy to reduce the moisture content of the fish. In this work, thermal analysis was carried out on the system after the design. The conduction and convection energy equations were applied to the system main component as well as the fish sample within the system. Numerical computational software (Scilab 6.0.0) was used in solving and analyzing the discretized form of the derived transient differential equations. Appropriate initial and boundary conditions were as well applied during the implementation of fully explicit forward and central difference numerical solutions for solving the differential equations. After solving and arriving at the temporal temperature profile of the dryer and the fish samples, other dependable parameters (energy consumed, exergy consumed, expended gas energy and exergy, energy and exergy efficiencies, etc.) were computed and plotted against time. After the result evaluation and testing, the designed machine proved successful and was found to have peak drying energy and exergy efficiencies of 90 % and 10% respectively.