In-Situ Continuous Coke Deposit Removal by Catalytic Steam Gasification for Fuel-Cooled Thermal Management

2012 ◽  
Vol 134 (10) ◽  
Author(s):  
He Huang ◽  
Xia Tang ◽  
Martin Haas
Keyword(s):  
Thermal Management ◽  
Coke Formation ◽  
Hydrocarbon Fuel ◽  
Steam Gasification ◽  
Enabling Technology ◽  
Coke Deposit ◽  
Cooling Technology ◽  
Aero Engines ◽  
Deposit Removal

Fuel-cooled thermal management, including endothermic cracking and reforming of hydrocarbon fuels, is an enabling technology for advanced aero engines and offers potential for cycle improvements and pollutant emissions control. The principal engine operability issue that will affect this enabling hydrocarbon fuel cooling technology is coke formation and deposition. Furthermore, the extent to which the benefits of high heat sink cooling technology can be realized is directly related to our ability to suppress coke formation and deposition. The successful implementation of this enabling technology is, therefore, predicated on coke suppression. In situ continuous coke deposit removal by catalytic steam gasification is being developed and successfully demonstrated as a means for suppressing pyrolytic coke deposit in fuel-cooled thermal management systems for advanced aero engines. The objective of this research is to investigate the in situ continuous coke deposit removal by catalytic steam gasification for suppressing pyrolytic coke deposition using a single-tube reactor simulator under representative hypersonic operating conditions. A coke removal system removes coke deposit from the walls of a high temperature passage in which hydrocarbon fuel is present. The system includes a carbon-steam gasification catalyst and a water source. The carbon-steam gasification catalyst is applied to the walls of the high temperature passage. The water reacts with the coke deposit on the walls of the fuel passage side to remove the coke deposit from the walls by carbon-steam gasification in the presence of the carbon-steam gasification catalyst. Experimental data shows the in situ continuous coke deposit removal by catalytic steam gasification is able to reduce coke deposit rate by more than ten times.

In-Situ Continuous Coke Deposit Removal by Catalytic Steam Gasification for Fuel-Cooled Thermal Management

2012 ◽  
Author(s):  
He Huang ◽  
Xia Tang ◽  
Martin Haas
Keyword(s):  
Thermal Management ◽  
Coke Formation ◽  
Hydrocarbon Fuel ◽  
Steam Gasification ◽  
Enabling Technology ◽  
Coke Deposit ◽  
Cooling Technology ◽  
Aero Engines ◽  
Deposit Removal

Fuel-cooled thermal management, including endothermic cracking and reforming of hydrocarbon fuels, is an enabling technology for advanced aero engines and offers potential for cycle improvements and pollutant emissions control. The principal engine operability issue that will affect this enabling hydrocarbon fuel cooling technology is coke formation. Furthermore, the extent to which the benefits of high heat sink cooling technology can be realized is directly related to our ability to suppress coke formation. The successful implementation of this enabling technology is, therefore, predicated on coke suppression. In-situ continuous coke deposit removal by catalytic steam gasification is being developed and successfully demonstrated as a means for suppressing pyrolytic coke deposit in fuel-cooled thermal management systems for advanced aero engines. The objective of this research is to investigate the in-situ continuous coke deposit removal by catalytic steam gasification for suppressing pyrolytic coke deposition using a single-tube reactor simulator under representative hypersonic operating conditions. A coke removal system removes coke deposit from the walls of a high temperature passage in which hydrocarbon fuel is present. The system includes a carbon-steam gasification catalyst and a water source. The carbon-steam gasification catalyst is applied to the walls of the high temperature passage. The water reacts with the coke deposit on the walls of the fuel passage side to remove the coke deposit from the walls by carbon-steam gasification in the presence of the carbon-steam gasification catalyst. Experimental data shows the in-situ continuous coke deposit removal by catalytic steam gasification is able to reduce coke deposit rate by more than 10 times.

The Use of In Situ Characterization Techniques for the Development of Intermetallic Titanium Aluminides

2014 ◽  
Vol 783-786 ◽  
pp. 2097-2102 ◽  
Author(s):  
Svea Mayer ◽  
Emanuel Schwaighofer ◽  
Martin Schloffer ◽  
Helmut Clemens
Keyword(s):  
Titanium Aluminides ◽  
Turbine Blades ◽  
Heat Treatments ◽  
Mechanical Processing ◽  
Tial Alloys ◽  
Solidification Processes ◽  
Consistent Picture ◽  
Aero Engines ◽  
Multi Phase

Urgent needs concerning energy efficiency and environmental politics require novel approaches to materials design. One recent example is thereby the implementation of light-weight intermetallic titanium aluminides as structural materials for the application in turbine blades of aero-engines as well as in turbocharger turbine wheels for the next generation of automotive engines. Each production process leads to specific microstructures which can be altered and optimized by thermo-mechanical processing and / or subsequent heat-treatments. To develop sound and sustainable processing routes, knowledge on solidification processes and phase transformation sequences in advanced TiAl alloys is fundamental. Therefore, in-situ diffraction techniques employing synchrotron radiation and neutrons were used for establishing phase fraction diagrams, investigating advanced heat-treatments as well as for optimizing thermo-mechanical processing. Summarizing all results a consistent picture regarding microstructure formation and its impact on mechanical properties in advanced multi-phase TiAl alloys can be given.

scholarly journals Hydrogenation and Dehydrogenation of Tetralin and Naphthalene to Explore Heavy Oil Upgrading Using NiMo/Al2O3 and CoMo/Al2O3 Catalysts Heated with Steel Balls via Induction

Catalysts ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 497 ◽  
Author(s):  
Abarasi Hart ◽  
Mohamed Adam ◽  
John P. Robinson ◽  
Sean P. Rigby ◽  
Joseph Wood
Keyword(s):  
Heavy Oil ◽  
Coke Formation ◽  
Plug Flow ◽  
Fixed Bed ◽  
Effect Of Temperature ◽  
Catalytic Upgrading ◽  
Heavy Oil Upgrading ◽  
Steel Balls ◽  
Surrounding Fluid

This paper reports the hydrogenation and dehydrogenation of tetralin and naphthalene as model reactions that mimic polyaromatic compounds found in heavy oil. The focus is to explore complex heavy oil upgrading using NiMo/Al2O3 and CoMo/Al2O3 catalysts heated inductively with 3 mm steel balls. The application is to augment and create uniform temperature in the vicinity of the CAtalytic upgrading PRocess In-situ (CAPRI) combined with the Toe-to-Heel Air Injection (THAI) process. The effect of temperature in the range of 210–380 °C and flowrate of 1–3 mL/min were studied at catalyst/steel balls 70% (v/v), pressure 18 bar, and gas flowrate 200 mL/min (H2 or N2). The fixed bed kinetics data were described with a first-order rate equation and an assumed plug flow model. It was found that Ni metal showed higher hydrogenation/dehydrogenation functionality than Co. As the reaction temperature increased from 210 to 300 °C, naphthalene hydrogenation increased, while further temperature increases to 380 °C caused a decrease. The apparent activation energy achieved for naphthalene hydrogenation was 16.3 kJ/mol. The rate of naphthalene hydrogenation was faster than tetralin with the rate constant in the ratio of 1:2.5 (tetralin/naphthalene). It was demonstrated that an inductively heated mixed catalytic bed had a smaller temperature gradient between the catalyst and the surrounding fluid than the conventional heated one. This favored endothermic tetralin dehydrogenation rather than exothermic naphthalene hydrogenation. It was also found that tetralin dehydrogenation produced six times more coke and caused more catalyst pore plugging than naphthalene hydrogenation. Hence, hydrogen addition enhanced the desorption of products from the catalyst surface and reduced coke formation.

scholarly journals Thermal Management Systems for Civil Aircraft Engines: Review, Challenges and Exploring the Future

2018 ◽  
Vol 8 (11) ◽  
pp. 2044 ◽  
Author(s):  
Soheil Jafari ◽  
Theoklis Nikolaidis
Keyword(s):  
Gas Turbine ◽  
Thermal Management ◽  
Cost Effective ◽  
Alternative Methods ◽  
Management Systems ◽  
Engine Efficiency ◽  
Future Challenges ◽  
Aero Engines ◽  
Historical Coverage ◽  
Electrical Components

This paper examines and analytically reviews the thermal management systems proposed over the past six decades for gas turbine civil aero engines. The objective is to establish the evident system shortcomings and to identify the remaining research questions that need to be addressed to enable this important technology to be adopted by next generation of aero engines with complicated designs. Future gas turbine aero engines will be more efficient, compact and will have more electric parts. As a result, more heat will be generated by the different electrical components and avionics. Consequently, alternative methods should be used to dissipate this extra heat as the current thermal management systems are already working on their limits. For this purpose, different structures and ideas in this field are stated in terms of considering engines architecture, the improved engine efficiency, the reduced emission level and the improved fuel economy. This is followed by a historical coverage of the proposed concepts dating back to 1958. Possible thermal management systems development concepts are then classified into four distinct classes: classic, centralized, revolutionary and cost-effective; and critically reviewed from challenges and implementation considerations points of view. Based on this analysis, the potential solutions for dealing with future challenges are proposed including combination of centralized and revolutionary developments and combination of classic and cost-effective developments. The effectiveness of the proposed solutions is also discussed with a complexity-impact correlation analysis.

Well-Aligned In-situ Formed Open-End Carbon Nanotube for Device and Assembly Applications

2006 ◽  
Vol 968 ◽  
Author(s):  
Lingbo Zhu ◽  
ChingPing Wong
Keyword(s):  
Carbon Nanotube ◽  
Thermal Management ◽  
Field Enhancement ◽  
High Carbon ◽  
Electrical Interconnects ◽  
Emission Testing ◽  
Reaction Furnace ◽  
Poor Adhesion ◽  
Good Agreement

ABSTRACTCarbon nanotubes (CNTs) have been proposed for applications in microelectronic applications, especially for electrical interconnects, thermal management, and nanodevices, due to their excellent electrical, thermal, and mechanical properties. In this paper, we reported a simple process to achieve simultaneous CNT growth and opening of the CNT ends, while keeping alignment of the original CNT films/arrays. The addition of relatively low reactivity oxidizing agents (water) into the reaction furnace enables the feasibility. We proposed using novel CNT transfer technology, enabled by open-ended CNTs, to circumvent the high carbon nanotube (CNT) growth temperature and poor adhesion with the substrates that currently plague CNT implementation. The process is featured with separation of high-temperature CNT growth and low-temperature CNT device assembly. Field emission testing of the as-assembled CNT devices is in a good agreement with the Fowler-Nordheim (FN) equation, with a field enhancement factor of 4540.

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