Cyrus B. Meher-Homji

Inlet Fogging of Gas Turbine Engines—Part I: Fog Droplet Thermodynamics, Heat Transfer, and Practical Considerations

The inlet fogging of gas turbine engines for power augmentation has seen increasing application over the past decade yet not a single technical paper treating the physics and engineering of the fogging process, droplet size measurement, droplet kinetics, or the duct behavior of droplets, from a gas turbine perspective, is available. This paper provides the results of extensive experimental and theoretical studies conducted over several years coupled with practical aspects learned in the implementation of nearly 500 inlet fogging systems on gas turbines ranging in power from 5 to 250 MW. Part A of the paper covers the underlying theory of droplet thermodynamics and heat transfer, and provides several practical pointers relating to the implementation and application of inlet fogging to gas turbine engines.

Inlet fogging of gas turbine engines. Part II: Fog droplet sizing analysis, nozzle types, measurement, and testing

The inlet fogging of gas turbine engines for power augmentation has seen increasing application over the past decade yet not a single technical paper treating the physics and engineering of the fogging process, droplet size measurement, droplet kinetics, or the duct behavior of droplets, from a gas turbine perspective, is available. This paper provides the results of extensive experimental and theoretical studies conducted over several years, coupled with practical aspects learned in the implementation of nearly 500 inlet fogging systems on gas turbines ranging in power from 5 to 250 MW. Part B of the paper treats the practical aspects of fog nozzle droplet sizing, measurement and testing presenting the information from a gas turbine fogging perspective. This paper describes the different measurement techniques available, covers design aspects of nozzles, provides experimental data on different nozzles and provides recommendations for a standardized nozzle testing method for gas turbine inlet air fogging.

Modeling and analysis of gas turbine performance deterioration

The effects of performance deterioration in both land and aircraft gas turbines are presented in this paper. Models for two of the most common causes of deterioration, viz., fouling and erosion, are presented. A stage-stacking procedure, which uses new installed engine field data for compressor map development, is described. The results of the effect of fouling in a powerplant gas turbine and that of erosion in a aircraft gas turbine are presented. Also described are methods of fault threshold quantification and fault matrix simulation. Results of the analyses were found to be consistent with field observations.

Inlet Fogging of Gas Turbine Engines: Climatic Analysis of Gas Turbine Evaporative Cooling Potential of International Locations

Inlet fogging of gas turbine engines has attained considerable popularity due to the ease of installation and the relatively low first cost compared to other inlet cooling methods. With increasing demand for power and with shortages envisioned especially during the peak load times during the summers, there is a need to boost gas turbine power. There is a sizable evaporative cooling potential throughout the world when the climatic data is evaluated based on an analysis of coincident wet bulb and dry bulb information. These data are not readily available to plant users. In this paper, a detailed climatic analysis is made of 106 major locations over the world to provide the hours of cooling that can be obtained by direct evaporative cooling. This data will allow gas turbine operators to easily make an assessment of the economics of evaporative fogging. The paper also covers an introduction to direct evaporative cooling and the methodology and data analysis used to derive the cooling potential. Simulation runs have been made for gas turbine simple cycles showing effects of fogging for a GE Frame 7EA and a GE Frame 9FA Gas turbine for 60 and 50 Hz applications.

Gas Turbine Axial Compressor Fouling And Washing.

Engineer, Turbomachinery Group, LNG Product Development Center, with Bechtel Corporation, in Houston, Texas. His 25 years of industry experience encompasses turbomachinery design, engine development, vibration and failure analysis, and the testing of gas turbines and compressors. He has developed several aerothermal and transient analysis techniques for the condition monitoring of gas turbines. In the past he was Chief Engineer of Mee Industries, Gas Turbine Division, and Boyce Engineering International Inc. Mr. Meher-Homji has a B.S. degree (Mechanical Engineering) from Shivaji University, an M.E. degree from Texas A&M University, and an MBA from the University of Houston. He is a member and past Chair of ASME’s International Gas Turbine Institute’s Industrial and Cogeneration Committee. Mr. MeherHomji was named Fellow of the ASME in 1997. He is a registered Professional Engineer in the State of Texas, and has several publications in the area of turbomachinery engineering.

Gas Turbine Performance Deterioration.

With privatization and intense competition in the utility and petrochemical industry, there is a strong incentive for gas turbine operators to minimize and control performance deterioration, as this directly affects profitability. The area of gas turbine recoverable and nonrecoverable performance deterioration is comprehensively treated in this paper. Deterioration mechanisms including compressor and turbine fouling, erosion, increased clearances, and seal distress are covered along with their manifestations, rules of thumb, and mitigation approaches. Permanent deterioration is also covered. Because of the importance of compressor fouling, gas turbine inlet filtration, fouling mechanisms, and compressor washing are covered in detail. Approaches for the performance monitoring of steady-state and transient behavior are presented along with simulations of common deterioration modes of gas turbine combined cycles. As several gas turbines are used in cogeneration and combined cycles, a brief discussion of heat recovery steam generator performance monitoring is made.

Inlet Fogging of Gas Turbine Engines: Part A — Theory, Psychrometrics and Fog Generation

Gas Turbine output is a strong function of the ambient air temperature with power output dropping by 0.3–0.5 % for every 1°F rise in ambient temperature. This loss in output presents a significant problem to utilities, cogenerators and IPPs when electric demands are high during the hot months. In the petrochemical and process industry, the reduction in output of mechanical drive gas turbines curtails plant output. One way to counter this drop in output is to cool the inlet air. The paper contrasts the traditional evaporative cooling technique with direct inlet fogging. The state of the art relating to fog generation and psychrometrics of inlet fogging are described.Copyright

Inlet Fogging of Gas Turbine Engines Detailed Climatic Analysis of Gas Turbine Evaporation Cooling Potential in the USA

Inlet fogging of gas turbine engines has attained considerable popularity due to the ease of installation and the relatively low first cost compared to other inlet cooling methods. With increasing demand for power and with shortage envisioned especially during the peak load times during the summers, there is a need to boost gas turbine power. There is a sizable evaporative cooling potential throughout the world when the climatic data is evaluated based on an analysis of coincident wet bulb and dry bulk information. These data are not readily available to plant users. In this paper a detailed climatic analysis is made of 122 locations in the U.S. to provide the hours of cooling that can be obtained by direct evaporative cooling. These data will allow gas turbine operators to easily make an assessment of the economics of evaporative cooling. The paper also covers an introduction to direct evaporative cooling and the methodology and data analysis used to derive the cooling potential in different regions of the U.S. Simulation runs have been made for gas turbine simple cycles using a reference plant based on a GE Frame 7111EA gas turbine at the 122 locations studied in the U.S. to provide a feel for the sensitivity of operation with inlet fogging.

Inlet Fogging of Gas Turbine Engines—Part III: Fog Behavior in Inlet Ducts, Computational Fluid Dynamics Analysis, and Wind Tunnel Experiments

The inlet fogging of gas turbine engines for power augmentation has seen increasing application over the past decade yet not a single technical paper treating the physics and engineering of the fogging process, droplet size measurement, droplet kinetics, or the duct behavior of droplets, from a gas turbine perspective, is available. This paper along with Parts I and II provides the results of extensive experimental and theoretical studies conducted over several years coupled with practical aspects learned in the implementation of nearly 500 inlet fogging systems on gas turbines ranging in power from 5 to 250 MW. In Part III of this paper, the complex behavior of fog droplets in the inlet duct is addressed and experimental results from several wind tunnel studies are covered.

Inlet Fogging of Gas Turbine Engines: Part C — Fog Behavior in Inlet Ducts, CFD Analysis and Wind Tunnel Experiments

The inlet fogging of gas turbine engines for power augmentation has seen increasing application over the past decade yet not a single technical paper treating the physics and engineering of the fogging process, droplet size measurement, droplet kinetics, or the duct behavior of droplets, from a gas turbine perspective, is available. This paper along with Parts A and B provides the results of extensive experimental and theoretical studies conducted over several years coupled with practical aspects learned in the implementation of nearly 500 inlet fogging systems on gas turbines ranging in power from 5 to 250 MW. In part C of this paper, the complex behavior of fog droplets in the inlet duct is addressed and experimental results from several wind tunnel studies are covered.Copyright