Analysis and Test of Coolant Flow and Heat Transfer of an Advanced Full-Coverage Film-Cooled Laminated Turbine Vane

A laminated and diffusion bonded turbine vane was designed and manufactured with stainless steel wafers. By the use of photo chemical etching, it was possible to make many elaborate and fine cooling passages. The description of the cooling passage construction is given in this paper. Coolant flow analysis has been done and corrected with the aid of preliminary coolant flow discharge test data without the mainstream. Cooling effectiveness analysis by cascade test has also been performed. Corrected flow analysis shows good agreement with the cascade test data. The resulting cooling effectiveness distribution shows relatively small deviation from the averaged value and it is located at the high level of 0.7 with a coolant flow rate ratio of 6 percent. The analysis and discussion are also presented in this paper.

Reliability Performance of Combustion Turbines in Combined Cycle Duty

There is a belief held by the electrical utility industry that the combustion turbine is unreliable and has a low availability value. This paper presents field data for combined cycle plants and concludes that the combustion turbine is, indeed, reliable. The importance of improved utility outage planning also is discussed in relation to increased availability values. Finally, areas for further attention are defined and will be the subject of future papers.

Methanol Dissociative Intercooling in Gas Turbines

This paper examines the possibility of injecting methanol into the compressor of a gas turbine, then dissociating it to carbon monoxide and hydrogen so as to cool the air and reduce the work of compression, while simultaneously increasing the fuel’s heating value. A theoretical analysis shows that there is a net reduction in compressor work resulting from this dissociative intercooling effect. Furthermore, by means of a computer cycle model, the effects of dissociation on efficiency and work per unit mass of airflow are predicted for both regenerated and unregenerated gas turbines. The effect on optimum pressure ratio is examined and practical difficulties likely to be encountered with such a system are discussed.

Prediction of Film Cooling Effectiveness of Steam

The intent of this work is to show, analytically, that superheated steam can provide better film cooling than conventional air for gas turbine blades and vanes. Goldstein’s two-dimensional and Eckert’s three-dimensional models have been reexamined and modified in order to include the effects of thermal-fluid properties of foreign gas injection on the film cooling effectiveness. Based on the modified models, the computed results for steam film cooling effectiveness, showing an increase of 80 to 100 percent when compared with air cooling at the same operating conditions, are presented.

Two-Phase Transpiration Cooling

Two-phase transpiration is shown to possess considerable potential for gas turbine cooling. In this concept, water fed into a porous component boils within the wall. The resulting steam issues from the hot surface forming the transpiration film. A model for the performance of such a system is developed. Assuming constant properties and a linear reduction of Stanton number with transpiration rate, closed-form solutions are obtained. The governing dimensionless parameters are identified, the system behavior predicted, and the modes of operation delineated. Those are defined as two-phase, partially-flooded, and completely-flooded modes. At low values of a certain “modified Peclet number,” the two-phase mode is unstable and the system tends to flood. Large values of this parameter indicate stable, well-regulated behavior. Discussions on gas turbine applications are presented. A typical numerical example is given in the Appendix.

The Design of an Advanced Cooled First Stage for a Full-Scale Utility Combustion Turbine

The design of an advanced cooled first stage for a full-scale utility size combustion turbine is discussed. The preliminary design work involved evaluating three candidate “skin/spar” concepts: the shell/spar, Lamilloy*/spar and hybrid configurations. A shell/spar concept at 1600°F (871°C) maximum metal temperature was selected for continued development because it ensures against transpiration hole plugging; temperature selection was based on performance and corrosion considerations. The detailed design of the shell/spar advanced cooled stage is featured in this presentation and includes heat transfer and mechanical designs, stress analyses and durability considerations, and material selection. The fabrication process and acceptance tests planned for the advanced cooling components are described along with the shop and field tests proposed for the demonstration engine.

Testing and Initial Operating Experience of the MS9001E Gas Turbine

A new 100-MW class gas turbine designed for world-wide 50-Hz utility application has been in operation at the Kirchlengern Station of the EMR power system in West Germany since December 1980. This paper describes the initial operating experience and the results of performance and other engineering test conducted at the customer site.

Stand-By Forced Draft Fan Versus Supercharging Gas Turbines for Pre-Combustion Air to Fully Fired Boilers in Combined Cycles

The purpose of this paper is to analyze the technical features of two different arrangements of supplying fresh air to the boilers in fully fired combined cycles for continuous boiler operation using a forced draft fan when the gas turbine is out of service. The first case is the conventional stand-by forced draft fan and the second is the supercharged fan arrangement. Two methods of separating the cycles are reviewed in detail: a) Cold start-up of system. b) While operating in the combined cycle mode, the gas turbine trips. c) While operating the boiler with fresh air firing the gas turbine is started for combined cycle operation. d) Normal shut down of the gas turbine. e) While operating in the combined cycle mode, the boiler trips. This paper presents the results of a study of a 350-MW combined cycle power plant for Alsands Energy Ltd., of Calgary, Alberta, Canada.

Some Environmental Considerations in Large Gas Turbine Power Stations

The increasing need to locate gas turbine power stations in the vicinity of residential sections forces the manufacturer to meet stringent noise abatement requirements which seems to get stricter as time progresses. This paper identifies major sources of noise emitted by gas turbine power stations, analyzes the techniques to reduce the emission and to suppress the propagation of this noise, describes practical approaches and reports measurements performed on medium and large size installations. Finally the economics of adequate silencing is considered.

Short Duration Heat Transfer Studies at High Free-Stream Temperatures

This paper describes short duration heat transfer measurements on a flat plate and a gas turbine nozzle airfoil at high free-stream temperatures. A shock tube generated the high temperature and pressure air flow. Thin-film heat gages recorded the surface heat flux. The flat plate was tested both in the shock tube and in a shock tunnel placed aft of the tube. Shock tunnel tests on the nozzle airfoil measured the local heat transfer distribution. The flat plate free-stream temperatures varied from 830 °R (460 K) to 3190 °R (1770 K) for a Tw/TT,g temperature ratio of 0.17 to 0.64 at Mach numbers from 0.12 to 1.34. The nozzle measurements at a Tw/TT,g of 0.35 to 0.39 generally indicate that pressure (concave) surface heat transfer coefficients are high, whereas the suction (convex) surface shows much lower heat transfer coefficients than a turbulent flat plate correlation.