Analysis on the Performance Characteristics of SOFC/GT Hybrid Systems Based on a Commercially Available MW-Class Gas Turbine

2005 ◽  
Author(s):  
Tae Won Song ◽  
Jeong L. Sohn ◽  
Tong Seop Kim ◽  
Sung Tack Ro
Keyword(s):  
Gas Turbine ◽  
Hybrid System ◽  
Guide Vane ◽  
Control Strategies ◽  
Operating Conditions ◽  
Performance Characteristics ◽  
Inlet Guide Vane ◽  
Part Load ◽  
Optimal Power ◽  
Selection Of

To investigate the possible applications of the SOFC/MGT hybrid system to large electric power generations, a study for the kW-class hybrid power system conducted in our group is extended to the MW-class hybrid system in this study. Because of the matured technology of the gas turbine and commercial availability in the market, it is reasonable to construct a hybrid system with the selection of a gas turbine as an off-the-shelf item. For this purpose, the performance analysis is conducted to find out the optimal power size of the hybrid system based on a commercially available gas turbine. The optimal power size has to be selected by considering specifications of a selected gas turbine which limit the performance of the hybrid system. Also, the cell temperature of the SOFC is another limiting parameter to be considered in the selection of the optimal power size. Because of different system configuration of the hybrid system, the control strategies for the part-load operation of the MW-class hybrid system are quite different from the kW-class case. Also, it is necessary to consider that the control of supplied air to the MW-class gas turbine is typically done by the variable inlet guide vane located in front of the compressor inlet, instead of the control of variable rotational speed of the kW-class micro gas turbine. Performance characteristics at part-load operating conditions with different kinds of control strategies of supplied fuel and air to the hybrid system are investigated in this study.

Control Strategies for Start-Up and Part-Load Operation of Solid Oxide Fuel Cell/Gas Turbine Hybrid System

2009 ◽  
Vol 7 (1) ◽  
Author(s):  
Wei Jiang ◽  
Ruixian Fang ◽  
Jamil Khan ◽  
Roger Dougal
Keyword(s):  
Fuel Cell ◽  
Gas Turbine ◽  
Hybrid System ◽  
Control Strategies ◽  
Operating Conditions ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Electrical Characteristics ◽  
Part Load ◽  
Start Up

Control strategy plays a significant role in ensuring system stability and performance as well as equipment protection for maximum service life. This work is aimed at investigating the control strategies for start-up and part-load operating conditions of the solid oxide fuel cell/gas turbine (SOFC/GT) hybrid system. First, a dynamic SOFC/GT hybrid cycle, based on the thermodynamic modeling of system components, has been successfully developed and simulated in the virtual test bed simulation environment. The one-dimensional tubular SOFC model is based on the electrochemical and thermal modeling, accounting for voltage losses and temperature dynamics. The single cell is discretized using a finite volume method where all the governing equations are solved for each finite volume. Two operating conditions, start-up and part load, are employed to investigate the control strategies of the SOFC/GT hybrid cycle. In particular, start-up control is adopted to ensure the initial rotation speed of a compressor and a turbine for a system-level operation. The control objective for the part-load operation regardless of load changes, as proposed, is to maintain constant fuel utilization and a fairly constant SOFC temperature within a small range by manipulating the fuel mass flow and air mass flow. To this end, the dynamic electrical characteristics such as cell voltage, current density, and temperature under the part load are simulated and analyzed. Several feedback control cycles are designed from the dynamic responses of electrical characteristics. Control cycles combined with control related variables are introduced and discussed.

Performance Study of a 1 MW Gas Turbine Using Variable Geometry Compressor and Turbine Blade Cooling

2010 ◽  
Author(s):  
Cleverson Bringhenti ◽  
Jesuino Takachi Tomita ◽  
Joa˜o Roberto Barbosa
Keyword(s):  
Gas Turbine ◽  
Guide Vane ◽  
Turbine Blades ◽  
Axial Flow ◽  
Operating Conditions ◽  
Inlet Guide Vane ◽  
Variable Geometry ◽  
Performance Study ◽  
Turbine Blade Cooling ◽  
Blade Cooling

This work presents the performance study of a 1 MW gas turbine including the effects of blade cooling and compressor variable geometry. The axial flow compressor, with Variable Inlet Guide Vane (VIGV), was designed for this application and its performance maps synthesized using own high technological contents computer programs. The performance study was performed using a specially developed computer program, which is able to numerically simulate gas turbine engines performance with high confidence, in all possible operating conditions. The effects of turbine blades cooling were calculated for different turbine inlet temperatures (TIT) and the influence of the amount of compressor-bled cooling air was studied, aiming at efficiency maximization, for a specified blade life and cooling technology. Details of compressor maps generation, cycle analysis and blade cooling are discussed.

scholarly journals Gas turbine efficiency and ramp rate improvement through compressed air injection

2020 ◽  
pp. 095765092093208 ◽  
Author(s):  
Kamal Abudu ◽  
Uyioghosa Igie ◽  
Orlando Minervino ◽  
Richard Hamilton
Keyword(s):  
Gas Turbine ◽  
Guide Vane ◽  
Injection Rate ◽  
Inlet Guide Vane ◽  
Heavy Duty ◽  
Part Load ◽  
Surge Margin ◽  
Rate Improvement ◽  
Heavy Duty Gas Turbine ◽  
Variable Inlet Guide Vane

With the transition to more use of renewable forms of energy in Europe, grid instability that is linked to the intermittency in power generation is a concern, and thus, the fast response of on-demand power systems like gas turbines has become more important. This study focuses on the injection of compressed air to facilitate the improvement in the ramp-up rate of a heavy-duty gas turbine. The steady-state analysis of compressed airflow injection at part-load and full load indicates power augmentation of up to 25%, without infringing on the surge margin. The surge margin is also seen to be more limiting at part-load with maximum closing of the variable inlet guide vane than at high load with a maximum opening. Nevertheless, the percentage increase in the thermal efficiency of the former is slightly greater for the same amount of airflow injection. Part-load operations above 75% of power show higher thermal efficiencies with airflow injection when compared with other load variation approaches. The quasi-dynamic simulations performed using constant mass flow method show that the heavy-duty gas turbine ramp-up rate can be improved by 10% on average, for every 2% of compressor outlet airflow injected during ramp-up irrespective of the starting load. It also shows that the limitation of the ramp-up rate improvement is dominated by the rear stages and at lower variable inlet guide vane openings. The turbine entry temperature is found to be another restrictive factor at a high injection rate of up to 10%. However, the 2% injection rate is shown to be the safest, also offering considerable performance enhancements. It was also found that the ramp-up rate with air injection from the minimum environmental load to full load amounted to lower total fuel consumption than the design case.

Gas Turbine Part Load Performance Testing: Comparison of Test Methodologies

2008 ◽  
Author(s):  
Thomas P. Schmitt ◽  
Herve Clement
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Guide Vane ◽  
Performance Testing ◽  
Load Level ◽  
Combined Cycle ◽  
Inlet Guide Vane ◽  
Performance Guarantee ◽  
Part Load ◽  
Advantages And Disadvantages

Current trends in usage patterns of gas turbines in combined cycle applications indicate a substantial proportion of part load operation. Commensurate with the change in operating profile, there has been an increase in the propensity for part load performance guarantees. When a project is structured such that gas turbines are procured as equipment-only from the manufacturer, there is occasionally a gas turbine part load performance guarantee that coincides with the net plant combined cycle part load performance guarantee. There are several methods by which to accomplish part load gas turbine performance testing. One of the more common methods is to operate the gas turbine at the specified load value and construct correction curves at constant load. Another common method is to operate the gas turbine at a specified load percentage and construct correction curves at constant percent load. A third method is to operate the gas turbine at a selected load level that corresponds to a predetermined compressor inlet guide vane (IGV) angle. The IGV angle for this third method is the IGV angle that is needed to achieve the guaranteed load at the guaranteed boundary conditions. The third method requires correction curves constructed at constant IGV, just like base load correction curves. Each method of test and correction embodies a particular set of advantages and disadvantages. The results of an exploration into the advantages and disadvantages of the various performance testing and correction methods for part load performance testing of gas turbines are presented. Particular attention is given to estimates of the relative uncertainty for each method.

Gas Turbine Airflow Control for Optimum Heat Recovery

1983 ◽  
Vol 105 (1) ◽  
pp. 72-79 ◽  
Author(s):  
W. I. Rowen ◽  
R. L. Van Housen
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Heat Recovery ◽  
Guide Vane ◽  
Control Mode ◽  
Cycle Performance ◽  
Inlet Guide Vane ◽  
Part Load ◽  
Exhaust Temperature ◽  
Cycle Efficiency

Gas turbines furnished with heat recovery equipment generally have maximum cycle efficiency when the gas turbine is operated at its ambient capability. At reduced gas turbine output the cycle performance can fall off rapidly as gas turbine exhaust temperature drops, which reduces the heat recovery equipment performance. This paper reviews the economic gains which can be realized through use of several control modes which are currently available to optimize the cycle efficiency at part load operation. These include variable inlet guide vane (VIGV) control for single-shaft units, and combined VIGV and variable high-pressure set (compressor) speed control for two-shaft units. In addition to the normal control optimization mode to maintain the maximum exhaust temperature, a new control mode is discussed which allows airflow to be modulated in response to a process signal while at constant part load. This control feature is desirable for gas turbines which supply preheated combustion air to fired process heaters.

Strategies to Enhance the Part-Load Performance of a SOFC/GT Hybrid System

2007 ◽  
Author(s):  
Jin Sik Yang ◽  
Jeong L. Sohn ◽  
Sung Tack Ro
Keyword(s):  
Gas Turbine ◽  
Hybrid Systems ◽  
Hybrid System ◽  
High Performance ◽  
Operating Conditions ◽  
Solid Oxide ◽  
Part Load ◽  
Performance Loss ◽  
High Level ◽  
Level Performance

In spite of the high performance characteristics of the solid oxide fuel cell / gas turbine (SOFC/GT) hybrid system, it is very difficult to maintain the high level performance under real application conditions, which generally require part-load operations. The performance loss of SOFC/GT hybrid systems under part-load operating conditions is closely related to that of the gas turbine. The power generated by the gas turbine in a hybrid system is much smaller than that generated by the SOFC. However, its contribution to the system efficiency is very important especially at part-load operating conditions. Therefore, to enhance the part-load performance of hybrid systems, it is useful to reduce the relative amount of power generated by a gas turbine that delivers lower performance than a SOFC. In the present study, several part-load operation strategies related to the gas turbine are studied and their impacts on the performance of a SOFC/GT hybrid system are discussed.

Part-Load Performance Analysis of Pressurized Molten Carbonate Fuel Cell/Micro-Gas Turbine Hybrid System Using a Commercially Available Micro-Gas Turbine

2009 ◽  
Author(s):  
Ai-guo Liu ◽  
Yi-wu Weng
Keyword(s):  
Fuel Cell ◽  
Gas Turbine ◽  
Hybrid System ◽  
Control Strategies ◽  
Molten Carbonate Fuel Cell ◽  
Inlet Temperature ◽  
Molten Carbonate ◽  
Part Load ◽  
Micro Gas Turbine ◽  
Carbonate Fuel Cell

This paper presented the work on the design and part-load operation of a power generation system composed of a pressurized molten carbonate fuel cell and a micro-gas turbine (MCFC/MGT). The gas turbine was based on the commercially available one and the MCFC was assumed to be newly designed for the hybrid system. The effect of different control strategies on the performance of system during part-load operation has been analyzed. Performance of system and gas turbine was compared at the same part-load considering the different control strategies. The results show that the system efficiency is lower compared with the same systems analyzed by the other authors. The system has good performance when both the turbine inlet temperature and cell temperature are maintained close to the design-point condition, but it is difficult for gas turbine to obtain the original power.

Shop Testing of the W501FD Gas Turbine at the Berlin Test Facility

2004 ◽  
Author(s):  
Selvam Veerappan ◽  
Abdullatif Chehab ◽  
Phillip Gravett ◽  
Robert Bland ◽  
Christof Lechner
Keyword(s):  
Gas Turbine ◽  
Guide Vane ◽  
Operating Conditions ◽  
Test Facility ◽  
Inlet Guide Vane ◽  
Load Testing ◽  
Engine Operation ◽  
Full Load ◽  
Wide Range ◽  
Reliability Performance

This paper describes the successful full load shop testing of the W501FD 190 MW-class 60 Hz gas turbine engine at the Berlin Test Facility in Germany. A three phase test program aimed at verifying and optimizing new design concepts for improving fleet reliability, performance and operational flexibility is presented. The Berlin test facility set-up, capabilities for continuous full load testing and extensive test instrumentation used to monitor critical engine parameters are described. Some of the verification testing includes speed variation with load, performance and emissions testing to cover a wide range of operating conditions. Engine operation includes inlet guide vane changes, alternate loading rates, shutdown, spin cooling and restarts to verify transient clearance effects and their effects on performance. Vital instrumentation includes compressor and turbine tip clearances, fluid and metal temperature measurements for rotating and stationary components at key locations.

Gas Turbine Airflow Control for Optimum Heat Recovery

1982 ◽  
Author(s):  
W. I. Rowen ◽  
R. L. Van Housen
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Heat Recovery ◽  
Guide Vane ◽  
Control Mode ◽  
Cycle Performance ◽  
Inlet Guide Vane ◽  
Part Load ◽  
Exhaust Temperature ◽  
Cycle Efficiency

Gas turbines furnished with heat recovery equipment generally have maximum cycle efficiency when the gas turbine is operated at its ambient capability. At reduced gas turbine output the cycle performance can fall off rapidly as gas turbine exhaust temperature drops, which reduces the heat recovery equipment performance. This paper reviews the economic gains which can be realized through use of several control modes which are currently available to optimize the cycle efficiency at part load operation. These include variable inlet guide vane (VIGV) control for single-shaft units, and combined VIGV and variable high pressure set (compressor) speed control for two-shaft units. In addition to the normal control optimization mode to maintain the maximum exhaust temperature, a new control mode is discussed which allows airflow to be modulated in response to a process signal while at constant part load. This control feature is desirable for gas turbines which supply preheated combustion air to fired process heaters.

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