Validation of a T100 Micro Gas Turbine Steady-State Simulation Tool

Abstract

Micro gas turbines (MGT) provide a highly efficient, low-pollutant way to generate power and heat on-site. MGTs have also proven to be a versatile technology platform for recent developments like utilization of fuels with low specific heating values and solar thermal electricity generation. Moreover, they are the foundation to build novel cycles like the inverted Brayton cycle or fuel cell hybrid power plants. Numerical simulations of steady operation points are beneficial in various phases of MGT cycle development. They are used to determine and analyze the future potentials of innovative cycles for example by predicting the electrical efficiency and they support the thermodynamic design process (by providing mass flow, pressure and temperature data). Numerical Simulation allows to approximate off-design performance of known cycles e.g. power output at different ambient conditions. Additionally, numerical simulation is used to support cycle optimization efforts by analyzing the sensitivity of component performance on cycle performance. Numerical models of the MGT components have to be tuned and validated based on experimental data from MGT test rigs. At DLR institute of combustion technology a MGT steady-state cycle simulation tool has been used to analyze a variety of cycles and has been revised for several years. In this paper, the validation process is discussed in detail. Comparing simulation data with measurement data from the DLR Turbec T100 test rig has led to extensions of the numeric models, on the one hand, and to modifications of the test rig on the other. Newly implemented numerical models account for the generator heat release to the inlet air and the power electronic limitations. The test rig was modified to improve the temperature measurement at positions with uneven spatial temperature distribution such as the turbine outlet. Analyzing these temperature distributions also yields a possible explanation for the apparent strong recuperator efficiency drop at high load levels, which was also observed by other T100 users before.

Performance analysis of the micro gas turbine Turbec T100 with a new FLOX-combustion system for low calorific fuels

“…In this paper, the program was used to investigate further potentials for optimization of the Turbec T100 with regard to operation with low calorific fuels. By using the obtained experimental data, the program has been validated analog to [24].…”

“…At DLR a numerical simulation program was developed to analyze the steady-state performance of the Turbec T100 [22][23][24]. The program is based on models for each MGT component and on extensive experimental data collected at the DLR MGT test rig.…”

A Highly Flexible Approach on the Steady-State Analysis of Innovative Micro Gas Turbine Cycles

“…The global solver is only one aspect of the MGTS 3 simulation tool. Other parts of the simulation tool were already described by Panne et al [3] and Henke et al [17]. In this section a short overview of the simulation tool is given with special emphasis on further developments not mentioned in previous publications.…”

“…The second method is for example useful during the design of new systems. Recuperators and water heat exchangers are calculated assuming a constant efficiency [1,17]. Other components implemented in MGTS 3 are combustion chambers [3], piping, flow branchings and mixers with or without recirculation, fuel cell models [3,5] and generators [17].…”

“…Pressure loss calculation can be selected as absolute, relative, proportional to the squared volume flow or proportional to the squared mass flow divided by the density. The first three methods are further described by Henke et al [17]. The last one is equivalent to the Darcy-Weisbach equation with a constant friction factor c f :…”