scholarly journals Exergy Analysis of Biomass-Fired Cogeneration Plant in a Pulp and Paper Mill

1993 ◽  
Author(s):  
Ann-Sofi E. Näsholm ◽  
Gunnar Svedberg ◽  
Mats O. J. Westermark
Keyword(s):  
Gas Turbine ◽  
Exergy Analysis ◽  
Waste Heat ◽  
Combined Cycle ◽  
Pulp And Paper ◽  
Energy Utilization ◽  
Saturated Steam ◽  
Total Efficiency ◽  
Steam Boiler ◽  
Cogeneration Plant

Second Law analysis or exergy analysis is a useful instrument to find ways to improve the efficiency of energy utilization. The method presents the magnitude and locations of true energy losses in an energy system. The pulp and paper industries have a big potential for increasing the energy efficiencies. An integration of a gas turbine with an existing steam turbine plant is one possible way to increase the energy efficiency and the power production. The cogeneration plant analysed in this paper is a hybrid combined plant in which two types of fuels are used. The exhaust gas from a combined cycle gas turbine via a waste heat recovery steam generator (HRSG) is used as preheated combustion air in a supplementary fired steam boiler. Saturated steam from the HRSG is assumed to be superheated in a boiler in which sludge, bark and other types of biomass are being used as fuels. To reduce the waste of energy, a flue gas driven fuel dryer is connected to evaporate some of the moisture in these biomass fuels. The study shows the effect of using a combined cycle instead of a simple steam cycle and the effect of using a fuel dryer. Among the configurations investigated, a plant with both a gas turbine and a fuel dryer yields the highest exergy efficiency and total efficiency. However, the net power efficiency is higher for a plant without a fuel dryer than for one with a fuel dryer.

Modern opportunities for preparation of ultra-pure water for feeding high-performance boiler plants

2020 ◽  
pp. 74-84
Author(s):  
A.A. Filimonova ◽  
◽  
N.D. Chichirova ◽  
A.A. Chichirov ◽  
A.A. Batalova ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
High Performance ◽  
Waste Heat ◽  
Pure Water ◽  
Combined Cycle ◽  
Feed Water ◽  
Operational Characteristics ◽  
Treatment Equipment

The article provides an overview of modern high-performance combined-cycle plants and gas turbine plants with waste heat boilers. The forecast for the introduction of gas turbine equipment at TPPs in the world and in Russia is presented. The classification of gas turbines according to the degree of energy efficiency and operational characteristics is given. Waste heat boilers are characterized in terms of design and associated performance and efficiency. To achieve high operating parameters of gas turbine and boiler equipment, it is necessary to use, among other things, modern water treatment equipment. The article discusses modern effective technologies, the leading place among which is occupied by membrane, and especially baromembrane methods of preparing feed water-waste heat boilers. At the same time, the ion exchange technology remains one of the most demanded at TPPs in the Russian Federation.

Evaluation of Energy Efficiency for a CCHP System With Available Microturbine

2007 ◽  
Author(s):  
H. X. Liang ◽  
Q. W. Wang
Keyword(s):  
Gas Turbine ◽  
Waste Heat ◽  
Energy System ◽  
Primary Energy ◽  
Economic Benefits ◽  
Optimal Operation ◽  
Energy Utilization ◽  
Utilization Efficiency ◽  
Energetic Efficiency ◽  
Efficiency Evaluation

This paper deals with the problem of energy utilization efficiency evaluation of a microturbine system for Combined Cooling, Heating and Power production (CCHP). The CCHP system integrates power generation, cooling and heating, which is a type of total energy system on the basis of energy cascade utilization principle, and has a large potential of energy saving and economical efficiency. A typical CCHP system has several options to fulfill energy requirements of its application, the electrical energy can be produced by a gas turbine, the heat can be generated by the waste heat of a gas turbine, and the cooling load can be satisfied by an absorption chiller driven by the waste heat of a gas turbine. The energy problem of the CCHP system is so large and complex that the existing engineering cannot provide satisfactory solutions. The decisive values for energetic efficiency evaluation of such systems are the primary energy generation cost. In this paper, in order to reveal internal essence of CCHP, we have analyzed typical CCHP systems and compared them with individual systems. The optimal operation of this system is dependent upon load conditions to be satisfied. The results indicate that CCHP brings 38.7 percent decrease in energy consumption comparing with the individual systems. A CCHP system saves fuel resources and has the assurance of economic benefits. Moreover, two basic CCHP models are presented for determining the optimum energy combination for the CCHP system with 100kW microturbine, and the more practical performances of various units are introduced, then Primary Energy Ratio (PER) and exergy efficiency (α) of various types and sizes systems are analyzed. Through exergy comparison performed for two kinds of CCHP systems, we have identified the essential principle for high performance of the CCHP system, and consequently pointed out the promising features for further development.

Gas Turbine Control System Integration for Royal Caribbean Millennium Class Cruise Liner

2000 ◽  
Author(s):  
David J. Olsheski ◽  
William W. Schulke
Keyword(s):  
Control System ◽  
Steam Turbine ◽  
Gas Turbine ◽  
Waste Heat ◽  
Combined Cycle ◽  
Direct Drive ◽  
Dynamic Features ◽  
Turbine Generator ◽  
Marine Propulsion ◽  
Prime Movers

Traditionally commercial marine propulsion needs have been met with direct drive reciprocating prime movers. In order to increase efficiency, simplify installation and maintenance accessibility, and increase cargo / passenger capacity; indirect electric drive gas and steam turbine combined cycle prime movers are being introduced to marine propulsion systems. One such application is the Royal Caribbean Cruise Line (RCCL) Millennium Class ship. This commercial vessel has two aero-derivative gas turbine generator sets with a single waste heat recovery steam turbine generator set. Each is controlled by independent microprocessor based digital control systems. This paper addresses only the gas turbine control system architecture and the unique safety and dynamic features that are integrated into the control system for this application.

Exergy Analysis of a Solid-Oxide Fuel Cell, Gas Turbine, Steam Turbine Triple-Cycle Power Plant

2012 ◽  
Author(s):  
Rebecca Z. Pass ◽  
Chris F. Edwards
Keyword(s):  
Fuel Cell ◽  
Power Systems ◽  
Solid Oxide Fuel Cell ◽  
Gas Turbine ◽  
Exergy Analysis ◽  
Combined Cycle ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Starting Point ◽  
Natural Gas Combined Cycle

In an effort to make higher efficiency power systems, several joint fuel cell / combustion-based cycles have been proposed and modeled. Mitsubishi Heavy Industries has recently built such a system with a solid-oxide fuel cell gas turbine plant, and is now working on a variant that includes a bottoming steam cycle. They report their double and triple cycles have LHV efficiencies greater than 52% and 70%, respectively. In order to provide insight into the thermodynamics behind such efficiencies, this study attempts to reverse engineer the Mitsubishi Heavy Industries system from publicly available data. The information learned provides the starting point for a computer model of the triple cycle. An exergy analysis is used to compare the triple cycle to its constituent sub-cycles, in particular the natural gas combined cycle. This analysis provides insights into the benefits of integrating the fuel cell and gas turbine architectures in a manner that improves the overall system performance to previously unseen efficiencies.

Lignite-Fired Combined Cycle Power Plant With ACPFBC: Concept and Thermodynamic Calculations

2003 ◽  
Author(s):  
Hans Joachim Krautz ◽  
Rolf Chalupnik ◽  
Franz Stuhlmu¨ller
Keyword(s):  
Power Plant ◽  
Gas Turbine ◽  
Fluidized Bed ◽  
Waste Heat ◽  
Ambient Air ◽  
Basic Function ◽  
Combined Cycle ◽  
Thermodynamic Calculations ◽  
Test Plant ◽  
Coal Conversion

A 200 kWth test plant was constructed by BTU Cottbus for the purpose of developing a special variant of coal conversion based on 2nd generation PFBC. This concept, primarily to be used for generating power from lignite, employs a circulating type fluidized bed and is characterized by a design that combines the two air-blown steps “partial gasification” and “residual char combustion” in a single component. The subject of this paper is to develop an overall power plant concept based on this process, and to perform the associated thermodynamic calculations. In addition to the base concept with one large heavy-duty Siemens gas turbine V94.3A fired with Lausitz dried lignite (19% H2O), further versions with variation of Siemens gas turbine model (V94.3A and V64.3A), the water content of the fuel fired (raw lignite with more than 52% H2O or dried lignite) as well as the method of drying the coal were investigated. Common assumptions for all versions were ISO conditions for the ambient air and a condenser pressure of 0.05 bar. As expected, the calculations yielded very attractive net efficiencies of almost 50% (LHV based) for a variant with the small V64.3A gas turbine and up to more than 55% for the large plants with the V94.3A gas turbine. It was further demonstrated that thermodynamic integration of an advanced, innovative coal drying process (e.g. fluidized-bed drying with waste heat utilization) causes an additional gain in net efficiency of about three percentage points compared with the variant of firing lignite that was first dried externally. In addition to the basic function of the coal conversion system, it was necessary to also assume preconditions such as complete carbon conversion, reliable hot gas cleaning facilities and fuel gas properties that are acceptable for combustion in the gas turbine. Put abstract text here.

The Experimental Research on Instantaneous Efficiency of PV/T Module Based on Micro Heat Pipe Array

2013 ◽  
Vol 732-733 ◽  
pp. 306-311
Author(s):  
Zhen Hua Quan ◽  
Lin Cheng Wang ◽  
Yao Hua Zhao ◽  
Yue Chao Deng ◽  
Gang Wang ◽  
...  
Keyword(s):  
Solar Cell ◽  
Heat Pipe ◽  
Thermal Efficiency ◽  
Power Efficiency ◽  
Waste Heat ◽  
Energy Utilization ◽  
Inlet Temperature ◽  
Total Efficiency ◽  
Micro Heat Pipe ◽  
Key Factor

A novel photovoltaic /thermal (PV/T) module is invented, which use micro heat pipe array (MHPA), a flat heat pipe, to cool the solar cell. The PV/T module can achieve the purpose of cogeneration by collecting and utilizing waste heat while cooling the solar cell and improving power efficiency. In order to test the performance of PV/T module based on MHPA, instantaneous thermal efficiency test was performed. The intercept of measured instantaneous thermal efficiency curve can reach 41.4%, the slope is 3.95. The temperature of PV module is the key factor of the influencing electric efficiency. The PV/T modules electric efficiency is kept between 10.5% and 12.3% during the test. Solar energy utilization total efficiency at 20°C inlet temperature can reach more than 50%, and comprehensive performance efficiency can reach above 70%.

System Study on Partial Gasification Combined Cycle With CO2 Recovery

2008 ◽  
Vol 130 (5) ◽  
Author(s):  
Yujie Xu ◽  
Hongguang Jin ◽  
Rumou Lin ◽  
Wei Han
Keyword(s):  
Gas Turbine ◽  
Thermal Efficiency ◽  
Rankine Cycle ◽  
Combined Cycle ◽  
Energy Utilization ◽  
Working Fluid ◽  
The Novel ◽  
Integrated Gasification Combined Cycle ◽  
Partial Gasification ◽  
Co2 Recovery

A partial gasification combined cycle with CO2 recovery is proposed in this paper. Partial gasification adopts cascade conversion of the composition of coal. Active composition of coal is simply gasified, while inactive composition, that is char, is burnt in a boiler. Oxy-fuel combustion of syngas produces only CO2 and H2O, so the CO2 can be separated through cooling the working fluid. This decreases the amount of energy consumption to separate CO2 compared with conventional methods. The novel system integrates the above two key technologies by injecting steam from a steam turbine into the combustion chamber of a gas turbine to combine the Rankine cycle with the Brayton cycle. The thermal efficiency of this system will be higher based on the cascade utilization of energy level. Compared with the conventional integrated gasification combined cycle (IGCC), the compressor of the gas turbine, heat recovery steam generator (HRSG) and gasifier are substituted for a pump, reheater, and partial gasifier, so the system is simplified obviously. Furthermore, the novel system is investigated by means of energy-utilization diagram methodology and provides a simple analysis of their economic and environmental performance. As a result, the thermal efficiency of this system may be expected to be 45%, with CO2 recovery of 41.2%, which is 1.5–3.5% higher than that of an IGCC system. At the same time, the total investment cost of the new system is about 16% lower than that of an IGCC. The comparison between the partial gasification technology and the IGCC technology is based on the two representative cases to identify the specific feature of the proposed system. The promising results obtained here with higher thermal efficiency, lower cost, and less environmental impact provide an attractive option for clean-coal utilization technology.

scholarly journals Combined Gas and Steam Cycle for a Gas-Cooled Solar Tower Power Plant

1981 ◽  
Author(s):  
B. Becker ◽  
H. H. Finckh ◽  
R. Meyer-Pittroff
Keyword(s):  
Power Plant ◽  
Energy Conversion ◽  
Gas Turbine ◽  
Steam Generator ◽  
Solar Power ◽  
Waste Heat ◽  
Radiant Energy ◽  
Combined Cycle ◽  
Conversion System ◽  
Energy Conversion System

In gas-cooled solar power plants the radiant energy of the sun is transferred to the cycle fluid in a cavity type solar receiver and converted into electric energy by means of a combined gas and steam turbine cycle incorporating a waste heat steam generator. The design and optimization of the energy conversion system in accordance with solar-specific considerations are described with particular regard to the gas turbine. In designing the energy conversion system several variants on the combined cycle with waste heat steam generator are investigated and special measures for the improvement of the cycle efficiency, such as the refinement of the steam process through the addition of pressure stages are introduced. It is demonstrated that the solar power plant meets the requirements both for straight solar and constant load operation with fossil fuel substitution. In order to establish the possibilities of attaining high part-load efficiencies in straight solar operation, two modes, variable and constant speed of the gas turbine, are compared with one another.

scholarly journals Combined Cycles Permit the Most Environmentally Benign Conversion of Fossil Fuels to Electricity

1990 ◽  
Author(s):  
Guenther Haupt ◽  
John S. Joyce ◽  
Konrad Kuenstle
Keyword(s):  
Environmental Impact ◽  
Power Plants ◽  
Fossil Fuels ◽  
Coal Gasification ◽  
High Efficiency ◽  
Waste Heat ◽  
Primary Energy ◽  
Combined Cycle ◽  
Point Of View ◽  
Steam Boiler

The environmental impact of unfired combined-cycle blocks of the GUD® type is compared with that of equivalent reheat steam boiler/turbine units. The outstandingly high efficiency of GUD blocks not only conserves primary-energy resources, but also commensurately reduces undesirable emissions and unavoidable heat rejection to the surroundings. In addition to conventional gas or oil-fired GUD blocks, integrated coal-gasification combined-cycle (ICG-GUD) blocks are investigated from an ecological point of view so as to cover the whole range of available fossil fuels. For each fuel and corresponding type of GUD power plant the most appropriate conventional steam-generating unit of most modern design is selected for comparison purposes. In each case the relative environmental impact is stated in the form of quantified emissions, effluents and waste heat, as well as of useful byproducts and disposable solid wastes. GUD blocks possess the advantage that they allow primary measures to be taken to minimize the production of NOx and SOx, whereas both have to be removed from the flue gases of conventional steam stations by less effective and desirable, albeit more expensive secondary techniques, e.g. flue-gas desulfurization and DENOX systems. In particular, the comparison of CO2 release reveals a significantly lower contribution by GUD blocks to the greenhouse effect than by other fossil-fired power plants.

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.

Sign in / Sign up

Export Citation Format

Share Document