Steady-State Modelling of Recuperator in OpenModelica

Abstract

This article develops a mathematical model for the heat exchange within a recuperator to improve the thermal efficiency of a micro-gas turbine system by recovering waste heat from the exhaust gas to the device. The effect of fin appearance and any properties on the optimal design is also studied with the NTU method. Since the temperatures at the outlet are not known, the NTU method is more practical than the LMTD method. The NTU method also accounts for the fluid heat capacity and heat transfer rates, making it more accurate for complex flow patterns and non-uniform heat transfer.

The calculations are modeled using OpenModelica, which is license-free, open-source, and suitable for development. Academics worldwide can exchange source code through this platform to accelerate progress. Therefore, it is ideal for designing customizable equipment that can be adjusted to meet the needs. The results obtained from the model, such as heat exchange rate, equipment size, fluid temperature, and fluid properties within the equipment, were validated against existing documentation and found to be accurate and consistent, with a tolerance of less than 2.1%.