Thermodynamic Performance of Wet Compression and Regenerative (WCR) Gas Turbine

2003 ◽  
Author(s):  
Qun Zheng ◽  
Minghong Li ◽  
Yufeng Sun
Keyword(s):  
Heat Exchanger ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Heat Recovery ◽  
Regenerative Process ◽  
Specific Power ◽  
Heat Recovery Steam Generator ◽  
Thermodynamic Performance ◽  
Wet Compression ◽  
Steam Heat

Thermodynamic performance of wet compression and regenerative (WCR) gas turbine are investigated in this paper. The regenerative process can be achieved by a gas/air (and steam) heat exchanger, a regenerator, or by a heat recovery steam generator and then the steam injected into the gas turbine. Several schemes of the above wet compression and regenerative cycles are computed and analyzed. The calculated results indicate that not only a significant specific power can be obtained, but also is the WCR gas turbine an economic competitive option of efficient gas turbines.

scholarly journals Repowering of a Small Utility: A Unique Solution to a Unique Problem

1979 ◽  
Author(s):  
L. F. Fougere ◽  
H. G. Stewart ◽  
J. Bell
Keyword(s):  
Steam Turbine ◽  
Gas Turbine ◽  
Steam Generator ◽  
Gas Turbines ◽  
Heat Recovery ◽  
Electric Utility ◽  
Combined Cycle ◽  
Steam Boiler ◽  
Heat Recovery Steam Generator ◽  
Turbine Generator

Citizens Utilities Company’s Kauai Electric Division is the electric utility on the Island of Kauai, fourth largest and westernmost as well as northernmost of the Hawaiian Islands. As a result of growing load requirements, additional generating capacity was required that would afford a high level of reliability and operating flexibility and good fuel economy at reasonable capital investment. To meet these requirements, a combined cycle arrangement was completed in 1978 utilizing one existing gas turbine-generator and one new gas turbine-generator, both exhausting to a new heat recovery steam generator which supplies steam to an existing steam turbine-generator. Damper controlled ducting directs exhaust gas from either gas turbine, one at a time, through the heat recovery steam generator. The existing oil-fired steam boiler remains available to power the steam turbine-generator independently or in parallel with the heat recovery steam generator. The gas turbines can operate either in simple cycle as peaking units or in combined cycle, one at a time, as base load units. This arrangement provides excellent operating reliability and flexibility, and the most favorable economics of all generating arrangements for the service required.

Semi-Closed Recuperated Cycle With Wet Compression

2017 ◽  
Author(s):  
Hans E. Wettstein
Keyword(s):  
Gas Turbine ◽  
Thermal Efficiency ◽  
Gas Turbines ◽  
Specific Power ◽  
Efficiency Gain ◽  
Lower Efficiency ◽  
Part Load ◽  
Thermal Transients ◽  
Wet Compression ◽  
Main Compressor

The semi-closed recuperated cycle (SCRC) has been suggested earlier by the author in several versions. The best of them used two compressors with one intercooling stage each. In this paper the intercooled main compressor has been replaced by a compressor with high fogging and no intercooling anymore. It is assumed that the system and the main compressor have its design points in the middle of the intended fogging water injection range. This turns out to allow another thermal efficiency gain by 2 to 3 percent points to clearly above 60% also combined with increased specific power related to the consumed combustion air and with no bottoming cycle. This paper demonstrates the technical feasibility based on Turbomachinery technologies, which have already proven commercial viability. The thermodynamic assumptions have been derived from existing gas turbine (GT) technology and are used within already confirmed operating ranges. With the same firing temperature also the thermal efficiency level of current Combined Cycles (GTCC) can be achieved. A special feature of the SCRC is the opportunity for inventory control of part load operation. This means that part load operation can be made by pressure reduction instead of temperature reduction as in open gas turbines. Thermal transients leading to hot part life consumption can therefore be avoided to a large extent and the combustor can operate at nearly constant temperature also at low part load with corresponding low emissions. Low part load operation achieves the same efficiency as base load. The result is more flexibility than in current GTCC technology associated with less complexity due to the needlessness of an extra bottoming cycle. Realizing this type of cycle aiming at its best efficiency potential however needs the development capability of a highly skilled gas turbine manufacturer. But it could also be developed for a lower efficiency range by using existing components with conservative data. The SCRC concept could also be aimed at combined heat and power applications or at naval propulsion by replacing CODOG’s. Due to its specific features the SCRC in general or with wet compression could be developed in the micro turbine power output size as well as up to above 1000MW single block size. Its inherent water condensation at elevated pressure makes an external source of make-up water obsolete.

scholarly journals The Constant Volume Gas Turbine: A Thermodynamic Assessment

1974 ◽  
Author(s):  
M. Zockel
Keyword(s):  
Heat Exchanger ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Constant Pressure ◽  
Pressure Ratio ◽  
Constant Volume ◽  
Specific Power ◽  
Inlet Temperature ◽  
Turbine Efficiency ◽  
Compressor Pressure Ratio

A quasi-steady-state analysis is made of the performance of a gas-turbine working with intermittent, constant volume combustion. Variables considered include inlet temperature, compressor pressure ratio, scavenge ratio, combustion time, heat exchanger thermal ratio. Characteristics are computed over a full loading range. Computations are based on turbines having the following behavior: (a) constant turbine efficiency, (b) characteristics of a multistage axial turbine, and (c) characteristics of a single-stage radial turbine. The analysis indicates that the constant volume gas turbine has advantages in thermal efficiency, specific power and part load performance over constant pressure gas turbines operating at the same compressor pressure ratio and turbine inlet temperature. However, the addition of a heat exchanger shows less advantage when applied to a constant volume than to a constant pressure engine.

scholarly journals Simulation of a Heat Recovery Steam Generator Operating in a Combined Cycle Plant

2013 ◽  
Author(s):  
Raphael Duarte ◽  
Sandro Ferreira ◽  
Rafael Barbosa
Keyword(s):  
Heat Exchanger ◽  
Power Plant ◽  
Steam Generator ◽  
Gas Turbines ◽  
Heat Recovery ◽  
Computational Models ◽  
Structural Changes ◽  
Combined Cycle ◽  
Heat Recovery Steam Generator ◽  
Energy Potential

The heavy duty gas turbines evolution led to higher combined cycle efficiencies. Thus, more complex heat recovery steam generators were developed in order to maximize the use of that energy potential. Therefore, computational models capable to predict the operational conditions of the equipment may be needed in order to analyze the system behavior for different situations. This article describes a computational model able to simulate the off-design behavior of a heat recovery steam generator (HRSG) operating in a combined cycle power plant. The model was developed so that it can be used in both model-based diagnostics systems and performance evaluation systems. Each heat exchanger inside the HRSG was designed individually and arranged according to the analyzed equipment. The computer code’s architecture was built in such a way that it can be easily changed, allowing the analysis of other HRSG’s configurations with simple structural changes, given the program’s modularity. In order to deal with the lack of details of the power plant equipment, which means not enough geometrical information of each heat exchanger, a generic algorithm tool was used to calibrate the heat exchangers models using only the measured data of the power plant SCADA. The developed program was validated against operational data from a real plant and showed satisfactory results, confirming the robustness of this model.

scholarly journals Direct Heat Cogeneration Applications for Kaolin Producers

1990 ◽  
Author(s):  
Jane P. Hill
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Heat Recovery ◽  
Economic Benefits ◽  
Economic Viability ◽  
Heat Recovery Steam Generator ◽  
Thermal Output ◽  
End Products ◽  
One Step ◽  
Silicate Clay

Direct heat cogeneration using gas turbines presents an unusually attractive means of supplying two end products when both are required simultaneously. Most cogeneration applications involve steam as the thermal end product. While steam has many industrial and commercial uses, the conversion of thermal output to usable steam involves losses in the heat recovery steam generator (HRSG). When the heat rejected by a gas turbine can be used directly, system losses can be minimized. One such application exists in the kaolin industry. Kaolin is a white alumina-silicate clay used in many products, including paper, medicines, plastics and paints. One step in producing kaolin requires large spray dryers, the heat for which can be supplemented by cogeneration. This study outlines conditions necessary to achieve economic viability with cogeneration and suggests ways to maximize economic benefits. Risks associated with cogeneration ventures are also discussed.

Acceptance Criteria for Heat Recovery Steam Generators Behind Gas Turbines

1986 ◽  
Author(s):  
Akber Pasha
Keyword(s):  
Gas Turbine ◽  
Steam Generator ◽  
Gas Turbines ◽  
Heat Recovery ◽  
Design Parameters ◽  
Heat Recovery Steam Generator ◽  
Exhaust Temperature ◽  
Input Parameters ◽  
Input Variables ◽  
Gas Turbine Exhaust

The design of a Heat Recovery Steam Generator behind a gas turbine depends upon various input parameters such as gas turbine exhaust flow, exhaust temperature, etc. Most of the input parameters are either measured with tolerances or calculated based on experimental correlations. The design of the heat recovery steam generator itself utilizes various correlations and empirical values. The errors or measurement tolerances in these variables affect the performance of the steam generator. This paper describes the various design parameters, the possible magnitude of errors in these parameters and the overall effect on the steam generator’s performance. By utilizing the information given in this paper, it is possible to develop a performance envelope based on the possible error margins of the input variables. The steam generator performance can be deemed acceptable if it is within this envelope.

scholarly journals The WISC Gas Turbine Engine

1997 ◽  
Author(s):  
A. Radey Shouman ◽  
A. R. Shouman
Keyword(s):  
Heat Exchanger ◽  
Gas Turbine ◽  
Thermal Efficiency ◽  
Heat Recovery ◽  
Gas Turbine Engine ◽  
Specific Power ◽  
Turbine Engine ◽  
Basic Engine ◽  
Exhaust Heat ◽  
Exhaust Heat Recovery

Combined gas turbine-steam turbine cycles have gained widespread acceptance as the most efficient utilization of the gas turbine for power generation, particularly for large power plants. In order to maximize the achievable thermal efficiency, more than one exhaust heat recovery boiler is used. The current trend is to use three boilers at three different operating pressures, which improves thermal efficiency but significantly increases the initial cost of the plant. There are advantages in replacing an exhaust heat recovery system using multiple boilers by a single heat exchanger in which the water side pressure is above the critical pressure of water; we shall refer to such a heat exchanger as a supercritical heat exchanger. The supercritical steam leaving the heat exchanger is expanded in a two phase turbine and then fed into the engine combustor. A condenser and a water treatment system are used to recover most of the water in the exhaust stream. A turbine system identical to the basic engine turbine system is added in parallel in order to allow for the operation with increased mass flow due to the steam injection. To achieve maximum efficiency such a turbine should be provided with variable area nozzles. With this arrangement, it becomes possible to inject sufficient steam to produce stoichiometric combustion at the desired turbine inlet temperature. We shall refer to this cycle as the Water Injected Stoichiometric Combustion (WISC) gas turbine cycle. The various components described above can be added to any existing gas turbine engine to change it to the WISC configuration. The WISC engine offers significant economical advantages. The specific power output per pound of air for the WISC engine is more than five times that of the basic engine, the thermal efficiency is 75% higher than that of the basic engine. This produces a significant reduction in the initial investment in the plant as well as its operating expenses.

scholarly journals Gas Turbine Heat Recovery Steam Generators for Combined Cycles Natural or Forced Circulation Considerations

1988 ◽  
Author(s):  
Akber Pasha
Keyword(s):  
Gas Turbine ◽  
Steam Generator ◽  
Heat Recovery ◽  
Power Plants ◽  
Natural Circulation ◽  
Combined Cycle ◽  
Heat Recovery Steam Generator ◽  
Steam Generators ◽  
Forced Circulation ◽  
Gas Turbine Exhaust

In recent years the combined cycle has become a very attractive power plant arrangement because of its high cycle efficiency, short order-to-on-line time and flexibility in the sizing when compared to conventional steam power plants. However, optimization of the cycle and selection of combined cycle equipment has become more complex because the three major components, Gas Turbine, Heat Recovery Steam Generator and Steam Turbine, are often designed and built by different manufacturers. Heat Recovery Steam Generators are classified into two major categories — 1) Natural Circulation and 2) Forced Circulation. Both circulation designs have certain advantages, disadvantages and limitations. This paper analyzes various factors including; availability, start-up, gas turbine exhaust conditions, reliability, space requirements, etc., which are affected by the type of circulation and which in turn affect the design, price and performance of the Heat Recovery Steam Generator. Modern trends around the world are discussed and conclusions are drawn as to the best type of circulation for a Heat Recovery Steam Generator for combined cycle application.

Thermodynamic Performance of Complex Gas Turbine Cycles

2002 ◽  
Author(s):  
Sanjay ◽  
Onkar Singh ◽  
B. N. Prasad
Keyword(s):  
Gas Turbine ◽  
Specific Power ◽  
Turbine Engines ◽  
Inlet Temperature ◽  
Air Cooling ◽  
Gas Turbine Engines ◽  
Current State ◽  
Thermodynamic Performance ◽  
Internal Convection ◽  
Plant Efficiency

This paper deals with the thermodynamic performance of complex gas turbine cycles involving inter-cooling, re-heating and regeneration. The performance has been evaluated based on the mathematical modeling of various elements of gas turbine for the real situation. The fuel selected happens to be natural gas and the internal convection / film / transpiration air cooling of turbine bladings have been assumed. The analysis has been applied to the current state-of-the-art gas turbine technology and cycle parameters in four classes: Large industrial, Medium industrial, Aero-derivative and Small industrial. The results conform with the performance of actual gas turbine engines. It has been observed that the plant efficiency is higher at lower inter-cooling (surface), reheating and regeneration yields much higher efficiency and specific power as compared to simple cycle. There exists an optimum overall compression ratio and turbine inlet temperature in all types of complex configuration. The advanced turbine blade materials and coating withstand high blade temperature, yields higher efficiency as compared to lower blade temperature materials.

New Concept of a Micro Gas Turbine Based Co-Generation Package for Performance Improvement in Practical Use

2005 ◽  
Author(s):  
Kenichiro Mochizuki ◽  
Satoshi Shibata ◽  
Umeo Inoue ◽  
Toshiaki Tsuchiya ◽  
Hiroko Sotouchi ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Steam Generator ◽  
Thermal Efficiency ◽  
Heat Recovery ◽  
Steam Injection ◽  
Operating Conditions ◽  
Market Potential ◽  
Injection System ◽  
Heat Recovery Steam Generator ◽  
Micro Gas Turbine

As the energy consumption has been increasing rapidly in the commercial sector in Japan, the market potential for the micro gas turbine is significant and it will be realized substantially if the thermal efficiency is improved. One of measures is to introduce the steam injection system using the steam generated by the heat recovery steam generator. Steam injection tests have been carried out using a micro gas turbine (Capstone C60). Test results showed that key performance parameters such as power output, thermal efficiency and emissions were improved by the steam injection. The stable operation of micro gas turbine with steam injection was confirmed under various operating conditions. Consequently, a micro gas turbine based co-generation package with steam injection driven by a heat recovery steam generator (HRSG) with supplementary firing is proposed.

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