Hybrid Dual-Fuel Combined Cycles: General Performance Analysis

2002 ◽  
Author(s):  
Miroslav P. Petrov ◽  
Andrew R. Martin ◽  
Laszlo Hunyadi
Keyword(s):  
Natural Gas ◽  
Power Plants ◽  
Small Scale ◽  
Dual Fuel ◽  
Low Grade ◽  
Steam Boiler ◽  
Electrical Efficiency ◽  
Combined Cycles ◽  
Gas Fuel ◽  
The Impact

The hybrid dual-fuel combined cycle concept is a promising technology for increasing the energy utilization of low-grade (solid) fuels. Advantages such as enhanced electrical efficiency, favorable economics, and relative ease of construction and operation have been pointed out by various authors in previous studies. The present investigation aims to assess the performance of natural gas and coal- or biomass-fired hybrid combined cycles, with a gas turbine as topping cycle and a steam boiler as bottoming cycle. A parametric analysis considers the impact of the natural gas/solid fuel energy ratio on the electrical efficiency of various hybrid system configurations. Results show that significant performance improvements (in the order of several percentage points in electrical efficiency) can be achieved by these hybrid configurations when compared to the reference (two independent, single-fuel power plants at the given scales). In large-scale power plants with coal-fired bottoming cycle, efficiencies continuously rise as the share of natural gas fuel is increased up to the cycle integration limits, while an optimum can be seen for the small-scale biomass-fired bottoming cycles (with modest steam parameters) at a certain share of natural gas fuel input.

Hybrid Dual-Fuel Combined Cycles for Small-Scale Applications With Internal Combustion Engines

2003 ◽  
Author(s):  
Miroslav P. Petrov ◽  
Thomas Stenhede ◽  
Andrew R. Martin ◽  
Laszlo Hunyadi
Keyword(s):  
Natural Gas ◽  
Power Plants ◽  
Internal Combustion Engines ◽  
Internal Combustion ◽  
Combined Cycle ◽  
Small Scale ◽  
Dual Fuel ◽  
Combustion Engines ◽  
Combined Cycles ◽  
Topping Cycle

Hybrid dual-fuel combined cycle power plants employ two or more different fuels (one of which is typically a solid fuel), utilized by two or more different prime movers with a thermal coupling in between. Major thermodynamic and economic advantages of hybrid combined cycle configurations have been pointed out by various authors in previous studies. The present investigation considers the performance of natural gas and biomass hybrid combined cycles in small scale, with an internal combustion engine as topping cycle and a steam boiler/turbine as bottoming cycle. A parametric analysis evaluates the impact of natural gas to biomass fuel energy ratio on the electrical efficiency of various hybrid configurations. Results show that significant performance improvements with standard technology can be achieved by these hybrid configurations when compared to the reference (two independent, single-fuel power plants at the relevant scales). Electrical efficiency of natural gas energy conversion can reach up to 57–58% LHV, while the efficiency attributed to the bottoming fuel rises with up to 4 percentage points. In contrast to hybrid cycles with gas turbines as topping cycle, hybrid configurations with internal combustion engines show remarkably similar performance independent of type of configuration, at low shares of natural gas fuel input.

Fuel Flexibility Influences on Premixed Combustor Blowout, Flashback, Autoignition and Instability

2006 ◽  
Author(s):  
Tim Lieuwen ◽  
Vince McDonell ◽  
Eric Petersen ◽  
Domenic Santavicca
Keyword(s):  
Natural Gas ◽  
Gas Turbine ◽  
Dynamic Stability ◽  
Current Understanding ◽  
Fuel Composition ◽  
Fuel Flexibility ◽  
Lean Premixed ◽  
Gas Fuel ◽  
The Impact ◽  
Underlying Processes

This paper addresses the impact of fuel composition on the operability of lean premixed gas turbine combustors. This is an issue of current importance due to variability in the composition of natural gas fuel supplies and interest in the use of syngas fuels. Of particular concern is the effect of fuel composition on combustor blowout, flashback, dynamic stability, and autoignition. This paper reviews available results and current understanding of the effects of fuel composition on the operability of lean premixed combustors. It summarizes the underlying processes that must be considered when evaluating how a given combustor’s operability will be affected as fuel composition is varied.

scholarly journals Internal Combustion Steam Cycle (G.I.S.T. Cycle): Thermodynamical Feasibility and Plant Lay-Out Proposals

1997 ◽  
Author(s):  
C. Caputo ◽  
M. Gambini ◽  
G. L. Guizzi
Keyword(s):  
Natural Gas ◽  
Power Plants ◽  
Internal Combustion ◽  
Steam Flow ◽  
Inlet Temperature ◽  
Steam Boiler ◽  
Critical Approach ◽  
Steam Power ◽  
Steam Power Plants ◽  
Steam Cycle

In this paper a new kind of steam cycle provided with internal combustion is proposed. The internal combustion of natural gas and compressed air inside the steam flow has been conceived to carry out a steam heating (SH a/o RH) until TIT (Turbine Inlet Temperature) much higher than those of the conventional steam power plants. By this internal combustion it seems possible to overcome the present limits to TIT in steam plants which are, as known, especially related to the technological problems of the superheater tube materials in the conventional external combustion steam boilers. The proposed cycle has been named with the acronym GIST (Gas Injection STeam) since the hot gases resulting from a combustion close to stechiometric conditions are injected inside the steam flow. This paper provides a first critical approach to these new kinds of thermodynamical cycles. At the first the thermodynamical and technological problems related to the combustion inside steam are explained and discussed. Then, different plant lay-out solutions are proposed with a critical discussion on their overall performance. At the last two GIST solution have been defined that seem very interesting: the first is an hybrid plant scheme (i.e. provided with multi-fuel supply) which involves performances higher than conventional steam power plants (net electric efficiency of about 47%); the second is a plant scheme with full natural gas supply (i.e. without multi-fuel steam boiler) wich involves very relevant performances (net electric efficiency of about 57%).

scholarly journals Research of parameters of the steam boiler BKZ-220-100 at joint burning of natural gas and low-grade fuel

2018 ◽  
Vol 194 ◽  
pp. 01020
Author(s):  
Elena Vorontsova ◽  
Andrey Gil ◽  
Alexander Romanenko
Keyword(s):  
Natural Gas ◽  
Brown Coal ◽  
Kuznetsk Coal ◽  
Low Grade ◽  
Steam Boiler ◽  
Local Power ◽  
Tomsk Region

In this article the research of prospects of use of low-grade brown coal of the Talovsky Deposit of the Tomsk region as fuel for local power is carried out. The study is carried out by checking calculations of the steam boiler BKZ–220–100. The result of the study is to obtain data on the parameters of the boiler during the combustion of brown talovsky coal as the main fuel, as well as in a mixture with natural gas or Kuznetsk coal.

scholarly journals What causes natural gas fuel shortages at U.S. power plants?

Energy Policy ◽  
2020 ◽  
Vol 147 ◽  
pp. 111805
Author(s):  
Gerad M. Freeman ◽  
Jay Apt ◽  
John Moura
Keyword(s):  
Natural Gas ◽  
Power Plants ◽  
Gas Fuel

A Computational Investigation of the Impact of Multiple Injection Strategies on Combustion Efficiency in Diesel-Natural Gas Dual Fuel Low Temperature Combustion Engine

2019 ◽  
Author(s):  
Lorenzo Bartolucci ◽  
Stefano Cordiner ◽  
Vincenzo Mulone ◽  
Sundar R. Krishnan ◽  
Kalyan K. Srinivasan
Keyword(s):  
Experimental Data ◽  
Low Temperature ◽  
Natural Gas ◽  
Combustion Efficiency ◽  
Dual Fuel ◽  
Pilot Injection ◽  
Low Temperature Combustion ◽  
Single Cylinder ◽  
Temperature Combustion ◽  
The Impact

Abstract Dual fuel diesel-methane low temperature combustion (LTC) has been investigated by various research groups, showing high potential for emissions reduction (especially oxides of nitrogen (NOx) and particulate matter (PM)) without adversely affecting fuel conversion efficiency in comparison with conventional diesel combustion. However, when operated at low load conditions, dual fuel LTC typically exhibit poor combustion efficiencies. This behavior is mainly due to low bulk gas temperatures under lean conditions, resulting in unacceptably high carbon monoxide (CO) and unburned hydrocarbon (UHC) emissions. A feasible and rather innovative solution may be to split the pilot injection of liquid fuel into two injection pulses, with the second pilot injection supporting the methane combustion once the process is initiated by the first one. In this work, diesel-methane dual fuel LTC is investigated numerically in a single-cylinder heavy-duty engine operating at 5 bar brake mean effective pressure (BMEP) at 85% and 75% percentage of energy substitution (PES) by methane (taken as a natural gas surrogate). A multidimensional model is first validated in comparison with experimental data obtained on the same single-cylinder engine for early single pilot diesel injection at 310 CAD and 500 bar rail pressure. With the single pilot injection case as baseline, the effects of multiple pilot injections and different rail pressures on combustion emissions are investigated, again showing good agreement with experimental data. Apparent heat release rate and cylinder pressure histories as well as combustion efficiency trends are correctly captured by the numerical model. Results prove that higher rail pressures yield reductions of HC and CO by 90% and 75%, respectively, at the expense of NOx emissions, which increase by ∼30% from baseline. Furthermore, it is shown that post-injection during the expansion stroke does not support the stable development of the combustion front as the combustion process is confined close to the diesel spray core.

Introducing ASME PTC 48

2014 ◽  
Author(s):  
Olivier Le Galudec ◽  
James Oszewski ◽  
John Preston ◽  
David Thimsen
Keyword(s):  
Co2 Capture ◽  
Carbon Capture ◽  
Power Plants ◽  
Performance Test ◽  
Heat Rate ◽  
Air Separation ◽  
Plant Performance ◽  
Small Scale ◽  
Separation Unit ◽  
Combined Cycles

In the field of Power Generation, Operators — Plant Owners, Utilities, IPPs … — have had to face severe constraints linked not only with price of electricity and cost of fuel, but also with more and more demanding environmental constraints. It appears that the next atmospheric emission coming under scrutiny is CO2. Some small scale laboratory size experiments and pilot scale tests demonstrating the ability to capture CO2 before it reaches the atmosphere have already been conducted, and some industrial scale demonstrators are already at the permitting stage and will soon reach construction. In order to anticipate the needs of Performance Tests within this coming market, ASME decided to form a new committee in order to prepare and deliver ASME Performance Test Code – PTC 48 “Overall Plant Performance with Carbon Capture” test code. This new code may be seen as an evolution of ASME PTC 46 “Performance Test Code on Overall Plant Performance” 1996 (currently under revision), which goes beyond the sole verification of components to provide guidelines for testing a full Plant. Capturing CO2 from fuel–fired power plants will have a significant impact on net capacity and net heat rate of the plant. Such plants will, in addition to the Power Block and Steam Generator, also include systems not commonly included in non-CO2 capture power plants. The addition of an ASU (Air Separation Unit, for oxy-combustion with CO2 capture) and/or CPU (CO2 Purification Unit, for oxy-combustion or post-combustion CO2 capture) has made necessary the preparation of a dedicated test code based upon same guiding principle than PTC 46, i.e. treating the plant globally as a “Black Box”. This approach allows correction of output and efficiency at the plant interfaces, but at the exclusion of internal parameters. It is anticipated that the code can inform development of regulations that define the rules and obligations of Operators. Currently, the proposed PTC 48 aims at fossil fuel fired Steam-electric power plants using either post-combustion CO2 capture or oxy-combustion with CO2 capture technologies. Combined cycles and Integrated Gasification Combined Cycles — IGCCs — are not addressed.

scholarly journals Analysis of Factors Affecting Thermodynamic Efficiency in Generation III+ PWR Nuclear Power Plants.

2017 ◽  
Vol 4 ◽  
pp. 141-154
Author(s):  
Marcus Vitlin ◽  
Miroshan Naicker ◽  
Augustine Frederick Gardner
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Rankine Cycle ◽  
Steam Temperature ◽  
Factors Affecting ◽  
Electrical Efficiency ◽  
Balance Of Plant ◽  
The Impact ◽  
The Relationship

Generation III+ reactors are the latest generation of Nuclear Power Plants to enter the market. The key evolution in these reactors is the introduction of stringent safety standards. This is done through thorough incident scenario analysis and preparation, resulting in the addition of novel active and passive auxiliary safety systems, affecting the power consumption in the balance of plant. This paper analyses the parameters of PWR power plants of similar design, to determine the parameters for optimal efficiency, regarding gross and net electrical output, determining the impact the balance of plant has on this efficiency. While two of the three main factors affecting the Rankine cycle – boiler pressure and steam temperature – behaved as theoretically expected, there was a notable point of departure with the third parameter – condenser pressure. The relationship between steam temperature and gross electrical efficiency was linear across all reactors but the relation between the steam temperature and the net electrical efficiency ceased to be linear for secondary loop steam temperatures above 290°C. The relationship between boiler pressure and both gross and net electrical efficiency was linear, proving the Rankine cycle. A relationship was not observed between the condenser pressure and either the gross or net electrical efficiency

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