Program development and simulation of dynamic operation of micro gas turbines

An in-house program that is capable of simulating the transient operations of micro gas turbines was developed. This paper describes the program setup and simulation of a commercial engine. Physics-based governing equations and characteristic models were applied to each component of the engine. The program was modularized fully using object-oriented programing for high maintainability and extensibility. To achieve both a short computing time and high accuracy, the recuperator was divided into multiple one-dimensional segments and its governing equation was linearized. To simulate a real commercial engine, scaled compressor and turbine performance maps, and the characteristic equations of the recuperator were adopted. The maps and the characteristic parameters of the recuperator were fine-tuned using the real operation data of the engine for better simulation accuracy. The thermal inertia of the recuperator, which plays a critical role in the transient behavior of the engine, was estimated using real shut-down data. The load following operation of the engine was simulated and close agreement with the test data was confirmed. The program is expected to be used for a range of purposes, such as supplementing the development test, designing robust control logic, and diagnosing the engine performance.