Performance Analysis of an Indirect Fired Air Turbine Cogeneration System

A thermodynamic study of an indirect fired air turbine cogeneration system for the production of electricity and process steam has been made. Performance data showing the effect of compressor compression ratio and turbine inlet temperature on fuel utilization efficiency (first law efficiency), electrical to thermal energy ratio (power to heat ratio) and second law efficiency (exergetic efficiency) have been generated. Although fuel utilization efficiency and electrical to thermal energy ratio data do provide some useful information, it is the second law efficiency that provides the optimal design conditions. The performance data contained in this study should be useful to the decision-makers in the selection of optimal parameters at the system design stage of an indirect fired air turbine cogeneration system.

Design and Construction of the First Commercial Cheng Cycle Series 7 Cogeneration Plant

A description is given of the Cheng Cycle Engine and its application to cogeneration based upon the first commercial plant. The paper covers a description of the plant and its components, unique design features, the automatic control system and the plant operational features. Initial operating performance and NOx emission characteristics are cited.

VEGA Combined Cycle Power Plants

A gas turbine is often associated with the steam cycle in the combined cycle electric power plants. Many plants of different combined cycle types are already in service, all distinguished by outstanding efficiency (45 to 47 %) and operating flexibility. We have thought it interesting to take stock of the steam and gas (VEGA) cycles especially destined for power plants. After outlining the thermodynamical optimization of the cycles, we shall develop the design and the practical realization of the combined cycle power plants.

Cogeneration Combined Cycle Achievements by the Dow Chemical Company in the Conservation of Energy

A review of the development and use of the gas turbine generator unit in The Dow Chemical Company for the cogeneration of steam and electric power energy for Dow’s major chemical complex. This review highlights the success and problems of Dow Chemical’s most recently constructed power plant at its Texas Division in Freeport, Texas. A review of Dow’s experience and developed technology to provide a reliable cogenerating plant.

Compressed Air Energy Storage: Plant Integration, Turbomachinery Development

Results of engineering and optimization of 25 MW and 50 MW turbomachinery trains for compressed air energy storage (CAES) power plant application are presented. Proposals submitted by equipment suppliers are based on commercially available equipment. Performance data and budget prices indicate that the CAES power plant is one of the most cost effective sources of providing peaking/intermediate power and load management. The paper addresses CAES power plant integration procedure and the specifics of turbomachinery design.

A Rational Efficiency Analysis of Comparisons and Trends in Gas Turbines for Cogeneration

The performance of gas turbines in cogeneration is examined by means of a second-law approach. Different cycle parameters, for both simple and regenerative design, are investigated together with different options for process or utility heat production. A reference electric power size of 4 MW is assumed for these comparisons. Results are presented as a set of parameters (electric power index, rational efficiency, coefficient of utilization). A new parameter, named versatility index, effectively indicates the broadness of the design thermal loads which can be handled by a gas turbine plant.

Gas Turbines in Cogeneration: Overall Analysis and Numerical Predictions

A methodology for the performance analysis of gas turbines for cogeneration applications is presented. Energy and exergy balances allow presentation of data in terms of either conventional or second-law parameters, as well as examination of the trends with respect to cycle variables and cogeneration options. The results show that, even though gas turbines (and particularly regenerative solutions) are very flexible for cogeneration purposes, care has to be exercised in matching thermal energy production conditions and cycle variables in order to achieve optimal performance.

Gas Turbine Heat Recovery Systems Predicting Fired Performance

Heat recovery systems generate steam by extracting heat from the gas turbine exhaust. This steam is used either in a steam turbine to generate power or as a heating and drying medium in a process. Most of the time it is a combination of both. Because of the cogeneration criteria and because of the independent power and process equipment, the HRS can no longer depend on gas turbine exhaust alone to produce the needed steam. Some sort of induct auxiliary firing is employed to satisfy the steam demand. The HRS, therefore, is needed to operate satisfactorily at various ambients and loads and at fired and unfired conditions. The design of the HRS should take into consideration all of these unfired and fired conditions so that the HRS operation can be stable over the operating range. There are numerous design parameters which affect the design and operational stability of the HRS and all these need to be reviewed at each operating condition for the design to be satisfactory. This paper presents charts and graphs which predict the probable values of these design parameters under various operating conditions. By utilizing these, the HRS user can establish the stability of the HRS performance over the operating range based on the specified design point parameters. If there is undesirable performance at a certain point, then either the operating condition or the design parameters can be changed. An HRS user can, by using these charts, be able to specify more realistic design parameters without a lengthly analysis by the HRS manufacturer which costs both money and time.

Investigation of Transient Technique for Turbine Vane Heat Transfer Using a Shock Tube

An investigation was made of a transient technique for determining heat transfer and flow conditions in a cascade of turbine vanes. A shock tube was used to establish, behind a reflected shock, temperature ratios between the gas the vanes simulating the severe operating conditions of modern gas turbines. Heat transfer and flow conditions at five locations (leading edge and 1/4 and 1/2 chord positions on suction and pressure surfaces) were determined by a heat flux gage and by flow visualization with a Mach-Zehnder interferometer. The heat flux gage was a thin-film semiconductor type thermocouple used to measure the surface temperature of a semi-infinite solid as a function of time. Then a transient analysis using a finite difference scheme was used to calculate the heat transfer. The validity of the transient technique was established by measurements with the thin-film gage mounted on the shock tube wall. Analytical results for steady, turbulent heat transfer to a flat plate are somewhat less than the measured results, the difference decreasing with increased shock strength. Analysis of the transient flow conditions in the shock tube provides an explanation of this behavior. The heat transfer conditions for the turbine vane are believed to be established rapidly enough to represent valid steady state measurements for the simulated turbine vane flow conditions.

Dual Energy Use Systems for Industrial, Commercial, and Building Applications

Integrated dual energy use systems, optimized to provide both electrical (or mechanical) and thermal energy for industrial process heating/cooling or for commercial and residential space conditioning needs, are energy efficient and economic alternatives to conventional single-purpose energy systems. Numerous prime movers, including diesels, gas engines, steam and gas turbines, combined cycles, and other advanced conversion systems, together with an array of different primary energy sources such as gas, oil, coal, biomass and municipal solid waste fuels and thermal storage and control strategies, can result in a complex variety of system configurations. The United Technologies Research Center (UTRC), working with the U.S. Department of Energy, the Electric Power Research Institute, and state and local governments, has developed methodologies and procedures to screen, evaluate, and select optimum dual energy use systems (DEUS) for industrial parks, commercial developments and residential applications or combinations thereof. This paper describes methodologies developed and provides examples of the dual use energy systems defined for use in: (1) single industries, (2) multiple-industry industrial parks, (3) recovery of waste heat from a nuclear fuel processing facility, and (4) burning of solid and municipal waste sources. In addition, specific sites are described which include residential, commercial and industrial developments being implemented in the Eastern and Western sections of the United States.