Development Study of 1500°C Class High Temperature Gas Turbine

This paper outlines the development programs of the next generation, 1500°C Class, high efficiency gas turbine. Combined cycle thermal efficiency of more than 55% (LHV) is expected to be obtained with metallic turbine components. To accomplish this, advancements must be made in the key technologies of NOx control, materials and cooling.

Reliability, Availability, and Maintainability Usage in the Development of the 501F Combustion Turbine and Auxiliaries

Westinghouse has been a strong supporter of Reliability, Availability, and Maintainability (RAM) principles during product design and development. This is exemplified by the actions taken during the design of the 501F engine to ensure that high reliability and availability was achieved. By building upon past designs, utilizing those features most beneficial, and improving other areas, a highly reliable product was developed. A full range of RAM tools and techniques were utilized to achieve this result, including reliability allocations, modelling, and effective redesign of critical components. These activities began during the conceptual design phase and will continue throughout the life cycle of these engines until they are decommissioned.

Aerodynamics and Heat Transfer Investigations on a High Reynolds Number Turbine Cascade

In this report the results of aerodynamic and heat transfer experimental investigations performed in a high Reynolds number turbine cascade test facility are analyzed. The experimental facility simulates the high Reynolds number flow conditions similar to those encountered in the space shuttle main engine. In order to determine the influence of Reynolds number on aerodynamic and thermal behavior of the blades, heat transfer coefficients were measured at various Reynolds numbers using liquid crystal temperature measurement technique. Potential flow calculation methods were used to predict the cascade pressure distributions. Boundary layer and heat transfer calculation methods were used with these pressure distributions to verify the experimental results.

Future Chemical Energy Networks

Much speculation on the future nature of electic utilities has concerned transmission; e.g., complications from access by multiple generators and how to effect higher line loadings to accommodate them. This paper proposes an alternative concept: pipeline transmission of a liquid fuel produced from domestic coal by nuclear heat at centralized facilities to multiple, dispersed sites for local generation and distribution of power.

Fuel Oil Storage Effect and Impact on Utility’s Gas Turbine Operation

The City of Austin Electric Utility, like other utilities in the country that experienced the natural gas curtailments brought about by the Arab oil embargo of the late seventies, purchased several million gallons of fuel oil and stored it for subsequent use as an alternative fuel in the event another gas shortage crisis befell the utility industry. As the price and availability of natural gas improved, gas was once again used exclusively as the primary fuel in utility boilers and gas turbines. Remaining fuel oil inventories were secured and attention to the fuel oil’s integrity and chemical stability over the years was forgotten. This paper focuses on the potential degradation of fuel oil that has been stored for several years, its impact on gas turbine operation, its rehabilitation, and a program for continued maintenance to insure reliable operation and compliance with equipment vendor specifications and operating permit emission requirements.

Three-Dimensional Flow Near the Blade/Endwall Junction of a Gas Turbine: Application of a Boundary Layer Fence

A flow management technique designed to reduce some harmful effects of secondary flow in the endwall region of a turbine passage is introduced. A boundary layer fence in the gas turbine passage is shown to improve the likelihood of efficient film cooling on the suction surface near the endwall. The fence prevents the pressure side leg of the horseshoe vortex from crossing to the suction surface and impinging on the wall. The vortex is weakened and decreased in size after being deflected by the fence. Such diversion of the vortex will prevent it from removing the film cooling flow allowing the flow to perform its cooling function. Flow visualization on the suction surface and through the passage shows the behavior of the passage vortex with and without the fence. Laser Doppler velocimetry is employed to quantify these observations.

Enhanced Full Coverage Impingement Heat Transfer With Obstacles in the Gap

Impingement heat transfer with turbulence enhancing obstacles in the impingement gap were investigated and compared with the unobstructed flow situation. The objective was to significantly enhance flat plate impingement heat transfer for gas turbine combustor external wall cooling applications. Large flow blockages were used in the form of ribs and slotted ribs. The latter were found to have the best heat transfer enhancement of up to 23% at the trailing edge. The main effect of the blockage was to considerably reduce the influence of crossflow on the heat transfer by preventing the deflection of the impingement jets by the crossflow.

Remote Condition Monitoring of a Peaking Gas Turbine

This paper illustrates how software and hardware for telecommunications and data acquisition enable cost-effective monitoring of peaking gas turbines using personal computers. It describes the design and evaluation of a system which transmits data from each start-up and shutdown over 1,500 miles to a monitoring computer. It presents system structure, interfaces, data content, and management. The system captures transient sequences of acceleration, synchronization, loading, thermal stabilization, steady operation, shutdown and cooldown; it yields coherent sets of speed, load, temperature, journal eccentricity, vibration amplitude, and phase at intervals appropriately spaced in time and speed. The data may be used to characterize and identify operational problems.

The Application of Convective Cooling Enhancement of Span-Wise Cooling Holes in a Typical First Stage Turbine Blade

A technique of heat transfer enhancement is investigated whereby the internal span-wise cooling passages of a typical first stage gas turbine blade are modified by the introduction of circumferential ribs. The technique is verified by the use of a test rig incorporating a heated internally ribbed tube operating at the same range of Mach and Reynolds numbers as the turbine blade as well as by a test rig incorporating actual production blades immersed in a heated oil bath.

Comparison of Time-Resolved Turbine Rotor Blade Heat Transfer Measurements and Numerical Calculations

Time-resolved turbine rotor blade heat transfer data are compared with ab initio numerical calculations. The data was taken on a transonic, 4-to-1 pressure ratio, uncooled, single-stage turbine in a short duration turbine test facility. The data consists of the time history of the heat transfer distribution about the rotor chord at midspan. The numerical calculation is a time accurate, 2-D, thin shear layer, multiblade row code known as UNSFLO. UNSFLO uses Ni’s Lax-Wendroff algorithm, conservative boundary conditions, and a time tilting algorithm to facilitate the calculation of the flow in multiple blade rows of arbitrary pitch ratio with relatively little computer time. The version used for this work had a simple algebraic Baldwin-Lomax turbulence model. The code is shown to do a good job of predicting the quantitative time history of the heat flux distribution. The wake/boundary layer and transonic interaction regions for suction and pressure surfaces are identified and the shortcomings of the current algebraic turbulence modelling in the code are discussed. The influence of hardware manufacturing tolerance on rotor heat transfer variation is discussed. A physical reasoning explaining the discrepancies between the unsteady measurement and the calculations for both the suction and pressure surfaces are given, which may be of use in improving future calculations and design procedures.