Design of fin plate heat exchanger for increasing micro turbine efficiency and introduction of fin plate heat exchanger design software (KhoshNasr) for this purpose

摘要

A heat exchanger is a part of micro turbines, which can improve thermal efficiency of micro turbines up to 30 percent. Some important factors in design of heat exchangers are low cost, high efficiency, small size, low weight and high performance. In this paper, design of a heat exchanger with consideration of Iranian industry's capability has been investigated. A survey of different types of gas to-gas heat exchangers is presented and then fin-tube heat exchanger, fin-plate heat exchanger, shell & tube heat exchanger and regenerator are designed. Also, the effect of thermo hydraulic parameters on the efficiency of the three heat exchangers is investigated. Effects of these heat exchangers on the efficiency of a 100 kW micro turbine are studied and the heat exchanger with the highest efficiency is selected. The algorithm for design and modeling of the selected heat exchanger is then presented. After research on all types of heat exchangers, fin plate heat exchanger appeared to be the optimum choice for manufacturing in Iran industry. A new design program was written in MATLAB based on our suggested algorithm. Since there were some practical charts about heat transfer and pressure drop in design of the heat exchanger, all the existing experimental curves related to heat transfer and pressure of fins (required in the design of the heat exchanger) were converted to data (using "Image Processing" technique in MATLAB) and implemented in the design program.