Development of a Recuperated Flameless Combustor for an Inverted Brayton Cycle Microturbine Used in Residential Micro-CHP

2017 ◽  
Author(s):  
Michel Delanaye ◽  
Andrés Giraldo ◽  
Rabia Nacereddine ◽  
Mehdi Rouabah ◽  
Valentina Fortunato ◽  
...  
Keyword(s):  
Natural Gas ◽  
Gas Turbine ◽  
Large Scale ◽  
High Efficiency ◽  
Low Cost ◽  
Primary Energy ◽  
Brayton Cycle ◽  
Cfd Modelling ◽  
Great Opportunity ◽  
Chp System

The paper presents recent work in the development of a clean and efficient natural gas combustor for a micro-CHP system based on a gas turbine for the residential sector. The large scale deployment of natural gas micro-CHP systems represents a great opportunity to contribute to a reduction of CO2 emissions by a substantial increase of the efficiency of primary energy source conversion. A micro-CHP system, well designed for a residential application, which means a power of 1kWe output and high efficiency (larger than 20%), may reduce annual household emissions up to factors close to 2.5. The micro-CHP system developed in this work uses a small gas turbine and an inverted Brayton cycle which advantageously allows the use of substantially larger turbomachinery components than a conventional pressurized Brayton cycle. The paper presents a new counterflow recuperator. Its design has been thoroughly studied by advanced 3D CFD to obtain compactness and high efficiency at low cost. A new flameless combustor has been developed in order to reduce to single digits the emissions of pollutants (NOx and CO) and obtain a highly efficient and stable combustion for various gases. The design methodology based on 3D CFD modelling is presented as well as experimental results demonstrating the performance of the recuperated flameless combustor for various operationg conditions.

Utilization of Cryogenic Exergy of LNG by MGT (Mirror Gas Turbine)

2000 ◽  
Author(s):  
Y. Tsujikawa ◽  
K. Kaneko ◽  
S. Fujii
Keyword(s):  
Natural Gas ◽  
Gas Turbine ◽  
High Efficiency ◽  
Electric Energy ◽  
Liquefied Natural Gas ◽  
Combined Cycle ◽  
Brayton Cycle ◽  
Exhaust Gas ◽  
Topping Cycle ◽  
Very High

In the course of the worldwide efforts to suppress the global warming, the saving energy becomes more important. Recently, the LNG (liquefied natural gas) terminals in our country have received more than 50 million tons of LNG per year. Therefore, the utilization of the cryogenic exergy in connection with the regasification of LNG gains more and more importance. The aim of this paper is the recovery of the energy consumed in liquefaction using the MGT (Mirror Gas Turbine), which is a kind of new combined cycle of a conventional gas turbine worked as a topping cycle and TG (inverted Brayton cycle) as a bottoming cycle. The optimum characteristics have been calculated and it is shown that this cycle is superior to the current-use gasification systems in employing seawater heats in terms of thermal efficiency and specific output. In the present cycle, the cold of LNG is used to cool the exhaust gas from a turbine of TG, and then the exergy of the liquefied natural gas is transformed to electric energy with a very high efficiency. The main feature of this new concept is the removal of an evaporation system using seawater.

Externally-Fired Combined Cycle Repowering of Existing Steam Plants

1993 ◽  
Author(s):  
Christian L. Vandervort ◽  
Mohammed R. Bary ◽  
Larry E. Stoddard ◽  
Steven T. Higgins
Keyword(s):  
Heat Exchanger ◽  
Steam Turbine ◽  
Gas Turbine ◽  
High Efficiency ◽  
Low Cost ◽  
Operating Experience ◽  
Capital Cost ◽  
Combined Cycle ◽  
Plant Design ◽  
Generating Capacity

The Externally-Fired Combined Cycle (EFCC) is an attractive emerging technology for powering high efficiency combined gas and steam turbine cycles with coal or other ash bearing fuels. The key near-term market for the EFCC is likely to be repowering of existing coal fueled power generation units. Repowering with an EFCC system offers utilities the ability to improve efficiency of existing plants by 25 to 60 percent, while doubling generating capacity. Repowering can be accomplished at a capital cost half that of a new facility of similar capacity. Furthermore, the EFCC concept does not require complex chemical processes, and is therefore very compatible with existing utility operating experience. In the EFCC, the heat input to the gas turbine is supplied indirectly through a ceramic heat exchanger. The heat exchanger, coupled with an atmospheric coal combustor and auxiliary components, replaces the conventional gas turbine combustor. Addition of a steam bottoming plant and exhaust cleanup system completes the combined cycle. A conceptual design has been developed for EFCC repowering of an existing reference plant which operates with a 48 MW steam turbine at a net plant efficiency of 25 percent. The repowered plant design uses a General Electric LM6000 gas turbine package in the EFCC power island. Topping the existing steam plant with the coal fueled EFCC improves efficiency to nearly 40 percent. The capital cost of this upgrade is 1,090/kW. When combined with the high efficiency, the low cost of coal, and low operation and maintenance costs, the resulting cost of electricity is competitive for base load generation.

Enhancing Gas Turbine Operation With Heavy Fuel Oil

2013 ◽  
Author(s):  
Vikram Muralidharan ◽  
Matthieu Vierling
Keyword(s):  
Power Generation ◽  
Natural Gas ◽  
Gas Turbine ◽  
Power Plants ◽  
High Efficiency ◽  
Combined Cycle ◽  
Fuel Oil ◽  
Residual Oil ◽  
Heavy Fuel Oil ◽  
Hydro Power

Power generation in south Asia has witnessed a steep fall due to the shortage of natural gas supplies for power plants and poor water storage in reservoirs for low hydro power generation. Due to the current economic scenario, there is worldwide pressure to secure and make more gas and oil available to support global power needs. With constrained fuel sources and increasing environmental focus, the quest for higher efficiency would be imminent. Natural gas combined cycle plants operate at a very high efficiency, increasing the demand for gas. At the same time, countries may continue to look for alternate fuels such as coal and liquid fuels, including crude and residual oil, to increase energy stability and security. In over the past few decades, the technology for refining crude oil has gone through a significant transformation. With the advanced refining process, there are additional lighter distillates produced from crude that could significantly change the quality of residual oil used for producing heavy fuel. Using poor quality residual fuel in a gas turbine to generate power could have many challenges with regards to availability and efficiency of a gas turbine. The fuel needs to be treated prior to combustion and needs a frequent turbine cleaning to recover the lost performance due to fouling. This paper will discuss GE’s recently developed gas turbine features, including automatic water wash, smart cooldown and model based control (MBC) firing temperature control. These features could significantly increase availability and improve the average performance of heavy fuel oil (HFO). The duration of the gas turbine offline water wash sequence and the rate of output degradation due to fouling can be considerably reduced.

scholarly journals High-resolution combinatorial patterning of functional nanoparticles

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Xing Xing ◽  
Zaiqin Man ◽  
Jie Bian ◽  
Yadong Yin ◽  
Weihua Zhang ◽  
...  
Keyword(s):  
Large Scale ◽  
High Efficiency ◽  
Low Cost ◽  
Dip Coating ◽  
Colloidal Nanoparticles ◽  
Pixel Size ◽  
Functional Nanoparticles ◽  
Error Ratio ◽  
Scientists And Engineers ◽  
Daunting Challenge

AbstractFast, low-cost, reliable, and multi-component nanopatterning techniques for functional colloidal nanoparticles have been dreamed about by scientists and engineers for decades. Although countless efforts have been made, it is still a daunting challenge to organize different nanocomponents into a predefined structure with nanometer precision over the millimeter and even larger scale. To meet the challenge, we report a nanoprinting technique that can print various functional colloidal nanoparticles into arbitrarily defined patterns with a 200 nm (or smaller) pitch (>125,000 DPI), 30 nm (or larger) pixel size/linewidth, 10 nm position accuracy and 50 nm overlay precision. The nanopatterning technique combines dielectrophoretic enrichment and deep surface-energy modulation and therefore features high efficiency and robustness. It can form nanostructures over the millimeter-scale by simply spinning, brushing or dip coating colloidal nanoink onto a substrate with minimum error (error ratio < 2 × 10−6). This technique provides a powerful yet simple construction tool for large-scale positioning and integration of multiple functional nanoparticles toward next-generation optoelectronic and biomedical devices.

A Low Cost ZSM-5 Zeolite Obtained from Rice Hull Ash

2005 ◽  
Vol 498-499 ◽  
pp. 676-680 ◽  
Author(s):  
A.A. Fernandes ◽  
E.U.C. Frajndlich ◽  
Humberto Gracher Riella
Keyword(s):  
Large Scale ◽  
High Efficiency ◽  
Low Cost ◽  
Amorphous Structure ◽  
Industrial Applications ◽  
Rice Hull ◽  
Rice Hull Ash ◽  
Industry Waste ◽  
Pure Silica ◽  
Zeolite Formation

The high pure synthetic zeolite have a large application in industry and agriculture, being nowadays in majority imported in Brazil. The biomass like rice hull ash (RHA), a rice industry waste, can be real advantageous in manufacture of different materials, since that is produced in large scale in the country. The silica extraction from RHA by alkaline leaching is a low energetic coast process and high efficiency, obtaining high pure silica with high reactive amorphous structure, very interesting for zeolite production. In this work was developed a economically feasible route for the production of high purity and crystallinity ZSM-5 zeolite, free of expensive template, starting from a low value intake, a industrial waste, producing a high value materials. The extracted silica from RHA in sodium silicate form is precipitated in the proper zeolite formation reactional mixture. The ZSM-5 have a lot of industrial applications due your high selectivity in catalytic reactions and high thermal and acid stability.

Performance and Cost Analysis of Advanced Gas Turbine Cycles With Precombustion CO2 Capture

2008 ◽  
Vol 131 (2) ◽  
Author(s):  
Stéphanie Hoffmann ◽  
Michael Bartlett ◽  
Matthias Finkenrath ◽  
Andrei Evulet ◽  
Tord Peter Ursin
Keyword(s):  
High Pressure ◽  
Power Plant ◽  
Natural Gas ◽  
Gas Turbine ◽  
Co2 Capture ◽  
Gas Turbines ◽  
High Efficiency ◽  
Combined Cycle ◽  
Co2 Separation ◽  
The Cost

This paper presents the results of an evaluation of advanced combined cycle gas turbine plants with precombustion capture of CO2 from natural gas. In particular, the designs are carried out with the objectives of high efficiency, low capital cost, and low emissions of carbon dioxide to the atmosphere. The novel cycles introduced in this paper are comprised of a high-pressure syngas generation island, in which an air-blown partial oxidation reformer is used to generate syngas from natural gas, and a power island, in which a CO2-lean syngas is burnt in a large frame machine. In order to reduce the efficiency penalty of natural gas reforming, a significant effort is spent evaluating and optimizing alternatives to recover the heat released during the process. CO2 is removed from the shifted syngas using either CO2 absorbing solvents or a CO2 membrane. CO2 separation membranes, in particular, have the potential for considerable cost or energy savings compared with conventional solvent-based separation and benefit from the high-pressure level of the syngas generation island. A feasibility analysis and a cycle performance evaluation are carried out for large frame gas turbines such as the 9FB. Both short-term and long-term solutions have been investigated. An analysis of the cost of CO2 avoided is presented, including an evaluation of the cost of modifying the combined cycle due to CO2 separation. The paper describes a power plant reaching the performance targets of 50% net cycle efficiency and 80% CO2 capture, as well as the cost target of 30$ per ton of CO2 avoided (2006 Q1 basis). This paper indicates a development path to this power plant that minimizes technical risks by incremental implementation of new technology.

Liquid Metal Printing for Manufacturing Large-Scale Flexible Electronic Circuits

2014 ◽  
Author(s):  
Yi Zheng ◽  
Zhi-Zhu He ◽  
Jun Yang ◽  
Jing Liu
Keyword(s):  
Liquid Metal ◽  
Large Scale ◽  
High Efficiency ◽  
Printed Electronics ◽  
Low Cost ◽  
Treatment Temperature ◽  
Consumer Electronics ◽  
Plastic Substrate ◽  
Electronic Circuits ◽  
Large Area

The advancement of printed electronics technology has significantly facilitated the development of electronic engineering. However, so far there still remain big barriers to impede the currently available printing technologies from being extensively used. Many of the difficulties came from the factors like: complicated ink-configurations, high post-treatment temperature, poor conductivity in room temperature and extremely high cost and time consuming fabrication process. From an alternative strategy, our recently invented desktop liquid metal printer offered a flexible way to better address the above deficiencies. Through modifying the system developed in the authors’ lab, here we demonstrated the feasibility of the method in quickly and reliably printing out various large area electronic circuits. Particularly, the liquid metal ink made of GaIn24.5 alloy, with a high electrical resistivity of 2.98×10−7 Ω·m, can be rapidly printed on polyvinyl chloride (PVC) substrate with maximum sizes spanning from centimeter size to meter large. Most important of all, all these manufactures were achieved at an extremely low cost level which clearly shows the ubiquitous value of the liquid metal printer. To evaluate the working performance of the present electronics fabrication method, the electrical resistance and wire width of the printed circuits were investigated under multiple overprinting cycles. For practical illustration purpose, LED lighting conductive patterns which can serve as a functional electronic decoration art were fabricated on the flexible plastic substrate. The present work sets up an example for directly making large-scale ending consumer electronics via a high-efficiency and low-cost way.

Experimental Testing of s-CO2 Regenerator for Use as a Replacement to High Cost Printed Circuit Recuperators for Use in s-CO2 Recompression Brayton Cycle

2016 ◽  
Author(s):  
Jacob F. Hinze ◽  
Gregory F. Nellis ◽  
Mark H. Anderson
Keyword(s):  
Thermal Energy ◽  
High Efficiency ◽  
Experimental Testing ◽  
Low Cost ◽  
Scale Model ◽  
Total Power ◽  
Brayton Cycle ◽  
Printed Circuit ◽  
Cold Fluid ◽  
Steel Balls

Supercritical Carbon Dioxide (sCO2) power cycles have the potential to deliver high efficiency at low cost. However, in order for s-CO2 cycle to reach high efficiency, highly effective recuperators are needed. These recuperative heat exchangers must transfer heat at a rate that is substantially larger than the heat transfer to the cycle itself and can therefore represent up to 24% of the total power block cost in a recompression Brayton cycle [1]. Lower cost regenerators are proposed as a cost saving alternative to high cost printed circuit recuperators. A regenerator is a heat exchanger that alternately has hot and cold fluid passing through it. During the first half of its cycle the hot gas is passed over a storage media bed (stainless steel balls, screens, or similar fill material) where thermal energy is stored. During the next half of the cycle, cold fluid is passed through in the opposite direction, extracting the thermal energy from the bed. By operating a cycle with two (or more) regenerators, where one is always in a hot to cold (HTC) blow and the other in a cold to hot blow (CTH), a quasi-steady state can be achieved in the cycle to allow continuous operation. A model of the regenerator was created and used in place of a recuperator in a model of a 10MW power plant. The thermal effectiveness of the regenerator cycle was slightly lower than the recuperator cycle, however the regenerator cycle had a saving of about 9.3 percent in the Levelized Cost of Energy (LCoE). A scale model of the regenerator is under construction which will verify the performance of the regenerator model.

Utilization of the Cold by LNG Vaporization With Closed-Cycle Gas Turbine

1980 ◽  
Vol 102 (2) ◽  
pp. 225-230 ◽  
Author(s):  
G. Krey
Keyword(s):  
Natural Gas ◽  
Gas Turbine ◽  
Optimization Design ◽  
High Efficiency ◽  
Electrical Energy ◽  
Liquefied Natural Gas ◽  
Partial Recovery ◽  
Closed Cycle ◽  
Save Energy ◽  
Very High

In the course of the world-wide efforts to save energy, the utilization of cold in connection with the regasification of liquefied natural gas gains more and more importance. The aim is the partial recovery of the energy consumed in liquefaction. There are particular advantages when using the closed-cycle gas turbine, in which the exergy of the liquefied natural gas is transformed to electrical energy with a very high efficiency. The paper deals with the optimization, design, and operational behavior of such a plant.

Nanophotonics silicon solar cells: status and future challenges

2015 ◽  
Vol 4 (4) ◽  
Author(s):  
Baohua Jia
Keyword(s):  
Solar Cells ◽  
High Performance ◽  
Large Scale ◽  
High Efficiency ◽  
Low Cost ◽  
Silicon Solar Cells ◽  
Solar Energy Harvesting ◽  
Material Usage ◽  
Future Challenges ◽  
Light Management

AbstractLight management plays an important role in high-performance solar cells. Nanostructures that could effectively trap light offer great potential in improving the conversion efficiency of solar cells with much reduced material usage. Developing low-cost and large-scale nanostructures integratable with solar cells, thus, promises new solutions for high efficiency and low-cost solar energy harvesting. In this paper, we review the exciting progress in this field, in particular, in the market, dominating silicon solar cells and pointing out challenges and future trends.

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