Experimental Investigation of the Dynamic Performance of a Micro Gas Turbine Recuperator Including Innovative Cycle Configurations

2010 ◽  
Author(s):  
Mario L. Ferrari ◽  
Alessandro Sorce ◽  
Matteo Pascenti ◽  
Aristide F. Massardo
Keyword(s):  
Gas Turbine ◽  
Mass Flow ◽  
Flow Rate ◽  
Control Strategies ◽  
Dynamic Performance ◽  
Transient Behavior ◽  
System Response ◽  
Test Rig ◽  
Micro Gas Turbine ◽  
Start Up

The aim of this work is the experimental analysis of steady-state and transient behavior of a primary surface recuperator installed in a 100 kW commercial micro gas turbine. The machine is integrated in an innovative test rig for high temperature fuel cell hybrid system emulation. It was designed and installed by the Thermochemical Power Group (TPG), at the University of Genoa, within the framework of the Felicitas and LARGE-SOFC European Integrated Projects. The high flexibility of the rig was exploited to perform tests on the recuperator operating in the standard cycle. Attention is mainly focused on its performance in transient conditions (start-up operations and load rejection tests). Start-up tests were carried out in both electrical grid-connected and stand-alone conditions, operating with different control strategies. Attention is focused on system response due to control strategy and on boundary temperature variation because of its influence on component life consumption. Further tests were carried out using the valves installed on the test rig to bypass the air side of the unit. Different operative conditions were analyzed to show the effect of different mass flow rates on recuperator behavior. Attention is mainly focused on recuperator performance when it operates in unbalanced flow rate conditions (i.e. different mass flow rate values in recuperator sides), as well as during advanced cycle start-up and shutdown operations.

Design and Characterization of an Inlet Duct for Mass Flow Measurement in a Micro Gas Turbine Test Rig

2014 ◽  
Author(s):  
C. Buratto ◽  
A. Carandina ◽  
M. Morini ◽  
C. Pavan ◽  
M. Pinelli ◽  
...  
Keyword(s):  
Noise Reduction ◽  
Gas Turbine ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Pressure Loss ◽  
Resistive Load ◽  
Test Rig ◽  
Micro Gas Turbine ◽  
Inlet Duct

In this paper, a test rig for experimentation on a micro gas turbine is presented. The test rig consists of a micro gas turbine Solar T-62T-32, which, coupled with a 50 kVA alternator, can supply electrical energy to a calibrated resistive load bank. Particular attention is paid to the design of the inlet duct for the mass flow rate measurement. The basic issue was to create the intake duct for a micro gas turbine (MGT) test rig, in order to provide precise data about the mass flow rate and the thermodynamic air characteristics in the MGT inlet section. The inlet duct is also designed in order to allow future tests on inlet cooling technologies. The MGT is incorporated in a chassis for noise reduction, the dimensions of which are 540 mm (height), 570 mm (width) and 940 mm (length). These small dimensions lead to problems with the insertion of the duct. Moreover, the intake of the compressor is not axial but radial, and this means that a volute must be foreseen to convey the flux into the MGT. Several shapes of volute are analyzed in this paper, considering the effects on the pressure loss and the induction of turbulence. The challenge was to develop a fluid-dynamically efficient duct with the hindrance of a very small available space between the compressor casing, the gearbox and the fuel pipes inside the narrow noise-reduction chassis. The mass flow rate will be computed by means of the differential static pressure between the upstream and the downstream section of a Venturi tube. The choice of a Venturi was due to the fact that it produces a pressure loss lower than any other device, such as orifice plates or other nozzle shapes. Furthermore, the expected mass flow rate would lead to high fluid speeds and, as a consequence, the diameter ratio between the duct and the throat of the Venturi was chosen to be as high as possible.

Emergency Shutdown Management in Fuel Cell Gas Turbine Hybrid Systems

2014 ◽  
Author(s):  
Fabio Lambruschini ◽  
Mario L. Ferrari ◽  
Alberto Traverso ◽  
Luca Larosa
Keyword(s):  
Fuel Cell ◽  
Gas Turbine ◽  
Control Strategies ◽  
University Campus ◽  
Time Dynamic ◽  
Micro Gas Turbine ◽  
Emergency Shutdown ◽  
Start Up ◽  
Pressure Stress ◽  
The University

A real-time dynamic model representing the pressurized fuel cell gas turbine hybrid system emulator test rig at Thermochemical Power Group (TPG) laboratories of the University of Genoa has been developed to study the fuel cell behavior during different critical operative situations like, for example, load changes (ramp and step), start-up and shut-down and, moreover, to implement an emergency shutdown strategy in order to avoid any damage to the fuel cell and to the whole system: focus has been on cathode/anode differential pressure, which model was validated against experimental data. The real emulator plant (located in Savona University campus) is composed of a 100 kW recuperated micro gas turbine, a modular cathodic vessel (4 modules of 0.8 m3 each) located between recuperator outlet and combustor inlet, and an anodic circuit (1 module of 0.8m3) based on the coupling of a single stage ejector with an anodic vessel. Different simulation tests were carried out to assess the behavior of cathode-anode pressure difference, identifying the best control strategies to minimize the pressure stress on fuel cell stack.

Aerodynamic Optimization of the Radial Inflow Turbine for a 100kW-Class Micro Gas Turbine Based on Metamodel-Semi-Assisted Method

2013 ◽  
Author(s):  
Shuai Shao ◽  
Qinghua Deng ◽  
Zhenping Feng
Keyword(s):  
Gas Turbine ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Total Pressure ◽  
Objective Functions ◽  
Aerodynamic Optimization ◽  
Micro Gas Turbine ◽  
Static Efficiency ◽  
Radial Inflow Turbine

In this paper, an aerodynamic optimization of the radial inflow turbine for a 100kW-class micro gas turbine is conducted based on the metamodel-semi-assisted idea. The idea is applied by first using the metamodel as a rapid exploration tool and then switching to the accurate optimization without metamodel for further exploration of the design space [1]. The non-dominated sorting genetic algorithm (NSGA-II) is used to drive the optimization process and the BP neural network is used to construct the metamodel. The optimization of this radial inflow turbine is divided into two parts, the stator optimization and the rotor optimization. The stator optimization is based on the accurate optimization strategy. The minimum total pressure loss of the stator and the maximum isentropic total-to-static efficiency of the stage are considered as the objective functions with constant mass flow rate as a constraint. The rotor optimization is conducted through the metamodel-semi-assisted idea. The maximum power output and isentropic total-to-static efficiency of the stage are considered as objective functions while keeping the mass flow rate to be constant. The accurate optimization system is demonstrated to be effective for the stator optimization, and the total pressure loss is reduced by 11.6% while the mass flow rate variation is less than 1%. The rotor optimization is conducted based on the metamodel-semi-assisted optimization and the results confirm the effectiveness of this new idea. The output power of the rotor increased by 1.5%, the isentropic total-to-static efficiency of the stage increased by 1.19% and the mass flow variation is less than 1%.

Feasibility Study on Dehydrogenation of LOHC Using Excess Exhaust Heat From a Hydrogen Fueled Micro Gas Turbine

2015 ◽  
Author(s):  
Balbina Hampel ◽  
Stefan Bauer ◽  
Norbert Heublein ◽  
Christoph Hirsch ◽  
Thomas Sattelmayer
Keyword(s):  
Gas Turbine ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Energy Supply ◽  
Excess Energy ◽  
Exhaust Gas ◽  
Distributed Energy ◽  
Micro Gas Turbine ◽  
Exhaust Heat

In recent years, renewable energy technologies have received increasing attention. However, the constant availability of renewable energies is not predictable, so that technologies for excess energy storage become increasingly important. One possibility for the technical implementation of such a storage technology is to bind hydrogen, produced using this excess energy, to liquid organic compounds, so-called Liquid Organic Hydrogen Carriers (LOHC), where hydrogen is bound to a H2-lean LOHC molecule in an exothermal hydrogenation reaction. The dehydrogenation process releases the stored hydrogen in an endothermal reaction. This technology offers advantages such as storage and transport safety, along with the high energy density. LOHC systems can assist in the realization of future distributed energy supply networks, as well. Micro gas turbines (MGT) play an important role in distributed energy supply, so that the coupling of a hydrogen fueled MGT with a reactor for the dehydrogenation process is a desirable achievement. In such a combined system, the excess exhaust enthalpy can be used to maintain the endothermal dehydrogenation reaction without affecting the overall efficiency of the gas turbine. This paper investigates the feasibility of a direct coupling between a hydrogen fueled recuperated micro gas turbine and the dehydrogenation process using the excess exhaust heat. For this purpose, a numerical simulation based on energy balances and thermodynamic equilibrium is implemented to model the process. Primary criteria for the evaluation of the process feasibility are the MGTs exhaust gas temperature, the exhaust gas mass flow rate, and the LOHC mass flow rate through the dehydrogenation unit. These three parameters specify the mass flow rate of LOHC, which can be dehydrogenated and thus, the mass flow rate of released hydrogen. Using the implemented numerical model, the suitability of two different LOHCs, N-Ethylcarbazole and an industrial heat transfer oil is investigated at two different pressure levels with respect to thermodynamic feasibility and process efficiency. The results show that the usable excess enthalpy in the exhaust gas of the investigated Turbec T100 MGT is sufficient to release enough hydrogen for re-use as fuel in the micro turbine process for three of the four investigated cases.

Micro-Gas Turbine Feed With Natural Gas and Synthesis Gas: Variation of the Turbomachines’ Operative Conditions With and Without Steam Injection

2017 ◽  
Author(s):  
Massimiliano Renzi ◽  
Carlo Caligiuri ◽  
Mosè Rossi
Keyword(s):  
Natural Gas ◽  
Gas Turbine ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Rotational Speed ◽  
Steam Injection ◽  
Working Fluid ◽  
Fluid Composition ◽  
Micro Gas Turbine

In this work, the performances of a 100 kW Micro Gas Turbine (MGT) fed by Natural Gas (NG) and three different biomass-derived Synthesis Gases (SGs) have been assessed using a MATLAB® simulation algorithm. The set of equations in the algorithm includes the thermodynamic transformations of the working fluid in each component, the performance maps that describe the turbomachines’ isentropic efficiencies and pressure ratios as a function of the reduced mass flow rate and the reduced rotational speed, the performance and the pressure losses in each component, as well as the consumption of the other auxiliary devices. The electric power output, achieved using SGs, turns out to be lower or higher with respect to the one produced with the NG, depending on the fuel Lower Heating Value (LHV) but also largely on the variation of the working fluid composition. In this work, the effect of the steam injection on the MGT performance characteristics has been also investigated. Steam injection allows to obtain higher power and efficiencies using both NG and SGs at the rated rotational speed, mainly thanks to the increase of the turbine enthalpy drop and the reduction of the compressor consumption. Attention must be paid to the risk of the compressor stall, especially when using SGs, as the mass flow rate processed by the compressor decreases significantly. Moreover, another advantage of adopting the steam injection technique lies in the increased flexibility of the system: according to the users’ needs, the discharged heat can be exploited to generate steam, thus to enhance the electric performances, or to supply thermal power.

Combustion Characteristics of a Micro Gas Turbine Combustor With Gamma-Shaped Porous Media Dome

2016 ◽  
Author(s):  
Liang Zhang ◽  
Chi Zhang ◽  
Xin Xue ◽  
Peihua Lin ◽  
Yuzhen Lin
Keyword(s):  
Porous Media ◽  
Gas Turbine ◽  
Mass Flow ◽  
Flow Rate ◽  
Gas Turbine Combustor ◽  
Reliable Operation ◽  
Air Mass ◽  
Micro Gas Turbine ◽  
Overall Efficiency ◽  
Micro Combustor

During the past decade, increasing interest has been shown in micro gas turbines for the high-power and high-energy density. However, due to the small characteristic scale, it is still a key problem to ensure safe and reliable operation of the micro-combustor. A new micro gas turbine combustor with a Γ-shaped porous media dome was investigated in this paper. The volume of the combustor is 2.7 cm3. Dual-zone combustion (combustion zone and dilution zone) was adopted in the combustor. Combustion characteristics of the micro-combustor with different total air mass flow and total equivalence ratios were investigated by experiments at ambient temperature and atmospheric pressure. The results show that the relationship between liner pressure-loss and total air mass flow cannot be fit by a polynomial due to porous media and dilution holes combined influence. The ratio of airflow across porous media dome to total air mass flow increased with increasing total air mass flow. Stable combustion was obtained in this micro combustor as the air mass flow rate was in the range of 0.15∼1.2 g/s. With the increasing total air mass flow, the total equivalence ratios of lean ignition and blow-out limits decreased first, then increased. The exit gas temperature as high as 1460 K and power density 636 MW/m3 were achieved at the total equivalence ratio of 0.5, and total air flow rate of 1.2 g/s, the overall efficiency reached 98.5% in this condition. The results showed that safe and reliable operation can be achieved in this new micro gas turbine combustor with high overall efficiency.

Emulation of Hybrid System Start-Up and Shutdown Phases With a Micro Gas Turbine Based Test Rig

2008 ◽  
Author(s):  
Mario L. Ferrari ◽  
Matteo Pascenti ◽  
Loredana Magistri ◽  
Aristide F. Massardo
Keyword(s):  
Control System ◽  
High Temperature ◽  
Fuel Cell ◽  
Power Systems ◽  
Gas Turbine ◽  
Hybrid System ◽  
Test Rig ◽  
Micro Gas Turbine ◽  
Start Up ◽  
Critical Phases

The aim of this work, focused on natural gas fired distributed power systems, is the experimental analysis of the start-up and shutdown for high temperature fuel cell hybrid systems. These critical phases have been emulated using the micro gas turbine test rig developed by TPG at the University of Genoa, Italy. The rig is based on the coupling of a modified commercial 100 kWe recuperated gas turbine with a modular volume designed to emulate fuel cell stacks of different dimensions. It is essential to test the dynamic interaction between the machine and the fuel cell, and to develop different operative procedures and control systems without any risk to the expensive stack. This paper shows the preliminary experimental results obtained with the machine connected to the volume. The attention is mainly focused on avoiding surge and excessive stress on the machine components during the tests. Finally, after the presentation of the valve control system, this paper reports the emulation of the hybrid system start-up and shutdown phases. They have been performed to produce a gradual heating up and cooling down of the fuel cell volume, using the cold bypass line, three high temperature valves, and the machine load control system. This approach is necessary to avoid high thermal stress on the cell material, extremely dangerous for the plant life.

scholarly journals Off-Design Dynamic Performance Analysis of a Solar Aided Coal-Fired Power Plant

Energies ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2950
Author(s):  
Vinod Kumar ◽  
Liqiang Duan
Keyword(s):  
Power Plant ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Thermal Efficiency ◽  
Dynamic Performance ◽  
Feed Water ◽  
Saving Rate ◽  
Coal Consumption ◽  
Dynamic Performance Analysis

Coal consumption and CO2 emissions are the major concerns of the 21st century. Solar aided (coal-fired) power generation (SAPG) is paid more and more attention globally, due to the lesser coal rate and initial cost than the original coal-fired power plant and CSP technology respectively. In this paper, the off-design dynamic performance simulation model of a solar aided coal-fired power plant is established. A 330 MW subcritical coal-fired power plant is taken as a case study. On a typical day, three various collector area solar fields are integrated into the coal-fired power plant. By introducing the solar heat, the variations of system performances are analyzed at design load, 75% load, and 50% load. Analyzed parameters with the change of DNI include the thermal oil mass flow rate, the mass flow rate of feed water heated by the solar energy, steam extraction mass flow rate, coal consumption, and the plant thermal efficiency. The research results show that, as DNI increases over a day, the coal saving rate will also increase, the maximum coal saving rate reaches up to 5%, and plant thermal efficiency reaches 40%. It is analyzed that the SAPG system gives the best performance at a lower load and a large aperture area.

Dynamic Simulation of a HRSG System for a Given Start-Up/Shut Down Curve

2011 ◽  
Author(s):  
Hun Cha ◽  
Yoo Seok Song ◽  
Kyu Jong Kim ◽  
Jung Rae Kim ◽  
Sung Min KIM
Keyword(s):  
Dynamic Analysis ◽  
Gas Turbine ◽  
Flow Rate ◽  
Exhaust Gas ◽  
Fuel Flow Rate ◽  
Fuel Flow ◽  
Start Up ◽  
Gas Turbine Exhaust ◽  
Main Steam ◽  
Duct Burner

An inappropriate design of HRSG (Heat Recovery Steam Generator) may lead to mechanical problems including the fatigue failure caused by rapid load change such as operating trip, start-up or shut down. The performance of HRSG with dynamic analysis should be investigated in case of start-up or shutdown. In this study, dynamic analysis for the HRSG system was carried out by commercial software. The HRSG system was modeled with HP, IP, LP evaporator, duct burner, superheater, reheater and economizer. The main variables for the analysis were the temperature and mass flow rate from gas turbine and fuel flow rate of duct burner for given start-up (cold/warm/hot) and shutdown curve. The results showed that the exhaust gas condition of gas turbine and fuel flow rate of duct burner were main factors controlling the performance of HRSG such as flow rate and temperature of main steam from final superheater and pressure of HP drum. The time delay at the change of steam temperature between gas turbine exhaust gas and HP steam was within 2 minutes at any analysis cases.

Model Analysis of Syngas Combustion and Emissions for a Micro Gas Turbine

2015 ◽  
Vol 137 (6) ◽  
Author(s):  
Chi-Rong Liu ◽  
Hsin-Yi Shih
Keyword(s):  
Gas Turbine ◽  
Flow Rate ◽  
Heat Input ◽  
Emission Characteristics ◽  
Nox Emissions ◽  
Fuel Flow Rate ◽  
Micro Gas Turbine ◽  
Fuel Flow ◽  
Temperature Distributions ◽  
Flame Structures

The purpose of this study is to investigate the combustion and emission characteristics of syngas fuels applied in a micro gas turbine, which is originally designed for a natural gas fired engine. The computation results were conducted by a numerical model, which consists of the three-dimension compressible k–ε model for turbulent flow and PPDF (presumed probability density function) model for combustion process. As the syngas is substituted for methane, the fuel flow rate and the total heat input to the combustor from the methane/syngas blended fuels are varied with syngas compositions and syngas substitution percentages. The computed results presented the syngas substitution effects on the combustion and emission characteristics at different syngas percentages (up to 90%) for three typical syngas compositions and the conditions where syngas applied at fixed fuel flow rate and at fixed heat input were examined. Results showed the flame structures varied with different syngas substitution percentages. The high temperature regions were dense and concentrated on the core of the primary zone for H2-rich syngas, and then shifted to the sides of the combustor when syngas percentages were high. The NOx emissions decreased with increasing syngas percentages, but NOx emissions are higher at higher hydrogen content at the same syngas percentage. The CO2 emissions decreased for 10% syngas substitution, but then increased as syngas percentage increased. Only using H2-rich syngas could produce less carbon dioxide. The detailed flame structures, temperature distributions, and gas emissions of the combustor were presented and compared. The exit temperature distributions and pattern factor (PF) were also discussed. Before syngas fuels are utilized as an alternative fuel for the micro gas turbine, further experimental testing is needed as the modeling results provide a guidance for the improved designs of the combustor.

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