Experimental study of a high-efficiency, low emission porous matrix combustor—heater

Fuel ◽  
1995 ◽  
Vol 74 (11) ◽  
pp. 1641-1647 ◽  
Author(s):  
Tian-Yu Xiong ◽  
Mark J. Khinkis ◽  
Ferol F. Fish
Keyword(s):  
Experimental Study ◽  
High Efficiency ◽  
Porous Matrix ◽  
Low Emission

A Porous Media Reciprocal Flow Burner With Embedded Heat Exchangers

2003 ◽  
Author(s):  
Fabiano Contarin ◽  
William M. Barcellos ◽  
Alexei V. Saveliev ◽  
Lawrence A. Kennedy
Keyword(s):  
Porous Media ◽  
High Efficiency ◽  
Porous Matrix ◽  
Heat Extraction ◽  
Flammability Limits ◽  
Transient Nature ◽  
Low Degree ◽  
Low Emission ◽  
Heat Regeneration ◽  
Regeneration Effect

Superadiabatic combustion in porous media allows a stable burning of ultra-lean methane/air mixtures, far below flammability limits. The heat regeneration effect of the porous matrix and the low degree of thermal non-equilibrium between the gas and the solid phases keep temperature values above the minimum necessary for combustion and hence the CO and NOx production at extremely low levels. Due to the transient nature of this phenomenon, a method to confine the combustion into a practical burner has been engineered. The Reciprocal Flow Burner (RFB) is an effective and simple system to achieve this result. A heat exchanger embedded into the pellets makes it an appealing alternative for high-efficiency low-emission heat production. In the present work, a numerical model is compared to experiments to provide a better understanding of heat extraction from a RFB.

An Experimental Study of Heat Transfer With an Impinging Circular Water Jet

2003 ◽  
Author(s):  
Hao Leng ◽  
Liejin Guo ◽  
Ximin Zhang ◽  
Hongbin Min ◽  
G.-X. Wang
Keyword(s):  
Heat Transfer ◽  
Experimental Study ◽  
High Efficiency ◽  
Impinging Jet ◽  
High Heat ◽  
Water Jet ◽  
Back Surface ◽  
High Tech ◽  
High Heat Flux ◽  
Transfer Coefficients

Impinging jet is widely used in both traditional industrial and new high-tech fields. High efficiency heat transfer in impinging jet cooling makes it an important method for heat transfer enhancement, in particular in cooling of electronic devices with high heat density. This paper presents an experimental study of heat transfer by an impinging circular water jet. A Constantan foil with the size of 5 mm × 5 mm was used to simulate a microelectronic chip with heat generated by passing an electrical current through the foil. A high heat flux over 106 W/m2 was achieved. The surface temperature was measured by a thermocouple glued onto the back surface of the foil. Both a free surface jet and a submerged jet were investigated. Effect of the nozzle-to-surface spacing as well as the jet speed at the exit of the nozzle on cooling was examined. By positioning the jet away from the center of the heating foil surface, the radial variation of the heat transfer coefficients over the foil was also investigated. Quantitative heat transfer data have been obtained and analyzed.

The Reheat Concept: The Proven Pathway to Ultra-Low Emissions and High Efficiency and Flexibility

2007 ◽  
Author(s):  
Felix Gu¨the ◽  
Jaan Hellat ◽  
Peter Flohr
Keyword(s):  
Power Generation ◽  
Gas Turbine ◽  
Flame Propagation ◽  
High Efficiency ◽  
Flame Stabilization ◽  
Auto Ignition ◽  
Fuel Flexibility ◽  
Stage Combustion ◽  
Low Emission ◽  
Key Topics

Reheat combustion has proven now in over 80 units to be a robust, and highly flexible gas turbine concept for power generation. This paper covers three key topics to explain the intrinsic advantage of reheat combustion to achieve ultra-low emission levels. First, the fundamental kinetic and thermodynamic emission advantage of reheat combustion is discussed analyzing in detail the emission levels of the first and second combustor stages, optimal firing temperatures for minimal emission levels, as well as benchmarking against single-stage combustion concepts. Secondly, the generic operational and fuel flexibility of the reheat system is emphasized, which is based on the presence of two fundamentally different flame stabilization mechanisms, namely flame propagation in the first combustor stage and auto-ignition in the second combustor stage. Finally, the present fleet status is reported by highlighting the latest combustor hardware upgrade and its emission performance.

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