Imperial College London
Alternate

Dr Andy Heyes

Faculty of Engineering, Department of Mechanical Engineering

Visting Professor
 
 
 
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Contact

 

a.heyes Website

 
 
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Location

 

605City and Guilds BuildingSouth Kensington Campus

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Summary

 

Publications

Publication Type
Year
to

58 results found

Pilgrim CC, Heyes AL, Feist JP, 2014, Thermal History Sensors for Non-Destructive Temperature Measurements in Harsh Environments, 10th International Conference on Barkhausen and Micro-Magnetics (ICBM), Publisher: AMER INST PHYSICS, Pages: 1609-1616, ISSN: 0094-243X

Conference paper

Pilgrim CC, Berthier S, Feist JP, Heyes ALet al., 2013, High resolution erosion detection in thermal barrier coatings using photoluminescent layers, SURFACE & COATINGS TECHNOLOGY, Vol: 232, Pages: 116-122, ISSN: 0257-8972

Journal article

Pilgrim CC, Feist JP, Heyes AL, 2013, On the effect of temperature gradients and coating translucence on the accuracy of phosphor thermometry, MEASUREMENT SCIENCE AND TECHNOLOGY, Vol: 24, ISSN: 0957-0233

Journal article

Abram C, Fond B, Heyes AL, Beyrau Fet al., 2013, High-speed planar thermometry and velocimetry using thermographic phosphor particles, APPLIED PHYSICS B-LASERS AND OPTICS, Vol: 111, Pages: 155-160, ISSN: 0946-2171

Journal article

Heyes AL, Rabhiou A, Kempf A, 2013, Oxidation of Divalent Rare Earth Phosphors for Thermal History Sensing, Sensors and Actuators B-Chemical, Vol: 177, Pages: 124-130

Journal article

Heyes AL, Rabhiou A, Feist JP, Kempf Aet al., 2013, Thermal History Sensing with Thermographic Phosphors, 9th International Temperature Symposium on Temperature - Its Measurement and Control in Science and Industry, Publisher: AMER INST PHYSICS, Pages: 891-896, ISSN: 0094-243X

Conference paper

Heyes AL, Pilgrim CC, Berthier S, Feist JP, Wellman RGet al., 2012, Photoluminescence for quantitative non-destructive evaluation of thermal barrier coating erosion, Surface Coatings and Technology, Vol: 209, Pages: 44-51

Journal article

Fond B, Abram C, Heyes AL, Kempf AM, Beyrau Fet al., 2012, Simultaneous temperature, mixture fraction and velocity imaging in turbulent flows using thermographic phosphor tracer particles., Optics Express, Vol: 20, Pages: 22118-22133

This paper presents an optical diagnostic technique based on seeded thermographic phosphor particles, which allows the simultaneous two-dimensional measurement of gas temperature, velocity and mixture fraction in turbulent flows. The particle Mie scattering signal is recorded to determine the velocity using a conventional PIV approach and the phosphorescence emission is detected to determine the tracer temperature using a two-color method. Theoretical models presented in this work show that the temperature of small tracer particles matches the gas temperature. In addition, by seeding phosphorescent particles to one stream and non-luminescent particles to the other stream, the mixture fraction can also be determined using the phosphorescence emission intensity after conditioning for temperature. The experimental technique is described in detail and a suitable phosphor is identified based on spectroscopic investigations. The joint diagnostics are demonstrated by simultaneously measuring temperature, velocity and mixture fraction in a turbulent jet heated up to 700 K. Correlated single shots are presented with a precision of 2 to 5% and an accuracy of 2%.

Journal article

Vick MJ, Jadaan OM, Wereszczak AA, Choi SR, Heyes AL, Pullen KRet al., 2012, Engine Design Strategies to Maximize Ceramic Turbine Life and Reliability, JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME, Vol: 134, ISSN: 0742-4795

Journal article

McGlashan NR, Childs PRN, Heyes AL, 2012, A Pb/Zn Based Chemical Looping System for Hydrogen and Power Production with Carbon Capture: GT2011-46602, Turbo Expo 2011: Power for Land, Sea and Air

This paper describes an extension of a novel, carbon-burning, fluid phase chemical looping combustion system proposed previously. The system generates both power and H2 with ‘inherent’ carbon capture using chemical looping combustion (CLC) to perform the main energy release from the fuel. A mixed Pb and Zn based oxygen carriers is used, and due to the thermodynamics of the carbothermic reduction of PbO and ZnO respectively, the system generates a flue gas which consists of a mixture of CO2 and CO. By product H2 is generated from this flue gas using the water-gas shift reaction (WGSR). By varying the proportion of Pb to Zn circulating in the chemical loop, the ratio of CO2 to CO can be controlled, which in turn enables the ratio between the amount of H2 produced to the amount of power generated to be adjusted. By this means, the power output from the system can be ‘turned down’ in periods of low electricity demand without requiring plant shutdown. To facilitate the adjustment of the Pb/Zn ratio, use is made of the mutual insolubility of the two metals at medium temperature to affect their segregation as two liquid layers at the base of the reduction reactor. The amount of Pb and Zn rich liquid drawn from the two layers and subsequently circulated around the system is controlled thereby varying the Pb/Zn ratio. To drive the endothermic reduction of ZnO that formed in the oxidiser, hot Zn vapour is ‘blown’ into the reducer where it condenses, releasing latent heat. The Zn vapour to produce this ‘blast’ of hot gas is generated in a flash vessel fed with hot liquid metal extracted from the oxidiser.A mass and energy balance is conducted of a power system, operating on the Pb/Zn cycle. In the analysis, reactions are assumed to reach equilibrium; losses associated with turbomachinery are considered; and heat exchangers are assigned a suitable approach temperature; however, pressure losses in equipment and pipework are assumed

Conference paper

Heyes AL, Botsis L, McGlashan NR, Childs PRNet al., 2012, A THERMODYNAMIC ANALYSIS OF CHEMICAL LOOPING COMBUSTION, ASME Turbo Expo 2011, Publisher: AMER SOC MECHANICAL ENGINEERS, Pages: 105-111

Conference paper

Heyes AL, Rabhiou A, Feist JP, Kempf AMet al., 2012, PHOSPHOR BASED TEMPERATURE INDICATING PAINTS, ASME Turbo Expo 2012, Publisher: AMER SOC MECHANICAL ENGINEERS, Pages: 927-+

Conference paper

Heyes AL, Feist JP, Kempf A, Skinner Set al., 2011, Phosphorescent Thermal History Sensors, Sensors and Actuators A-Physical, Vol: 169, Pages: 18-26

Journal article

Heyes AL, Taylor NP, Chen J, 2011, Characterising shortwave instabilities on a vortex dipole, EXPERIMENTS IN FLUIDS, Vol: 51, Pages: 237-245, ISSN: 0723-4864

Journal article

McGlashan NR, Childs PRN, Heyes AL, 2011, Chemical looping combustion using the direct combustion of liquid metal in a gas turbine based cycle, Journal of Engineering for Gas Turbines and Power, Vol: Vol 133, Pages: 031701-1-031701-13, ISSN: 0742-4795

Journal article

McGlashan NR, Childs PRN, Heyes AL, 2011, Chemical Looping Combustion Using the Direct Combustion of Liquid Metal in a Gas Turbine Based Cycle, Journal of Engineering for Gas Turbines and Power, Vol: 133

A combined cycle gas-turbine generating power and hydrogen is proposed and evaluated.The cycle embodies chemical looping combustion (CLC) and uses a Na based oxygencarrier. In operation, a stoichiometric excess of liquid Na is injected directly into thecombustion chamber of a gas-turbine cycle, where it is burnt in compressed O2 producedin an external air separation unit (ASU). The resulting combustion chamber exit streamconsists of hot Na vapor and this is expanded in a turbine. Liquid Na2O oxide is alsogenerated in the combustion process but this can be separated, readily, from the Na vaporand collects in a pool at the bottom of the reactor. To regenerate liquid Na from Na2O,and hence complete the chemical loop, a reduction reactor (the reducer) is fed with threestreams: the hot Na2O from the oxidizer, the Na vapor (plus some entrained wetness)exiting a Na-turbine, and a stream of solid fuel, which is assumed to be pure carbon forsimplicity. The sensible heat content of the liquid Na2O and latent and sensible heat ofthe Na vapor provide the heat necessary to drive the endothermic reduction reaction andensure the reducer is externally adiabatic. The exit gas from the reducer consists ofalmost pure CO, which can be used to generate byproduct H2 using the water-gas shiftreaction. A mass and energy balance of the system is conducted assuming reactions reachequilibrium. The analysis allows for losses associated with turbomachinery; heat exchangersare assumed to operate with a finite approach temperature. However, pressurelosses in equipment and pipework are assumed negligible—a reasonable assumption forthis type of analysis that will still yield meaningful data. The analysis confirms that thecombustion chamber exit temperature is limited by both first and second law considerationsto a value suitable for a practical gas-turbine. The analysis also shows that theoverall efficiency of the cycle, under optimum conditions and taking into account thework necessary to dr

Journal article

Vick MJ, Heyes A, Pullen K, 2010, Design Overview of a Three Kilowatt Recuperated Ceramic Turboshaft Engine, JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME, Vol: 132, ISSN: 0742-4795

Journal article

McGlashan NR, Childs PRN, Heyes AL, Marquis AJet al., 2010, Producing Hydrogen and Power Using Chemical Looping Combustion and Water-Gas Shift, JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME, Vol: 132, Pages: 031401-1-031401-10, ISSN: 0742-4795

A cycle capable of generating both hydrogen and power with “inherent” carbon capture is proposed and evaluated. The cycle uses chemical looping combustion to perform the primary energy release from a hydrocarbon, producing an exhaust of CO. This CO is mixed with steam and converted to H2 and CO2 using the water-gas shift reaction (WGSR). Chemical looping uses two reactions with a recirculating oxygen carrier to oxidize hydrocarbons. The resulting oxidation and reduction stages are preformed in separate reactors—the oxidizer and reducer, respectively, and this partitioning facilitates CO2 capture. In addition, by careful selection of the oxygen carrier, the equilibrium temperature of both redox reactions can be reduced to values below the current industry standard metallurgical limit for gas turbines. This means that the irreversibility associated with the combustion process can be reduced significantly, leading to a system of enhanced overall efficiency. The choice of oxygen carrier also affects the ratio of CO versus CO2 in the reducer's flue gas, with some metal oxide reduction reactions generating almost pure CO. This last feature is desirable if the maximum H2 production is to be achieved using the WGSR reaction. Process flow diagrams of one possible embodiment using a zinc based oxygen carrier are presented. To generate power, the chemical looping system is operated as part of a gas turbine cycle, combined with a bottoming steam cycle to maximize efficiency. The WGSR supplies heat to the bottoming steam cycle, and also helps to raise the steam necessary to complete the reaction. A mass and energy balance of the chemical looping system, the WGSR reactor, steam bottoming cycle, and balance of plant is presented and discussed. The results of this analysis show that the overall efficiency of the complete cycle is dependent on the operating pressure in the oxidizer, and under optimum conditions exceeds 75%.

Journal article

Rabhiou A, Feist J, Kempf A, Skinner S, Heyes Aet al., 2010, CONCEPT FOR A PHOSPHORESCENT THERMAL HISTORY SENSOR, ASME Turbo Expo 2010, Publisher: AMER SOC MECHANICAL ENGINEERS, Pages: 343-351

Conference paper

Hansel RA, Desai SK, Allison SW, Heyes AL, Walker DGet al., 2010, Emission lifetimes of europium-doped pyrochlores for phosphor thermometry, JOURNAL OF APPLIED PHYSICS, Vol: 107, ISSN: 0021-8979

Journal article

Heyes AL, 2009, On the Design of Phosphors for High Temperature Thermometry, Journal of Luminescence, Vol: 129, Pages: 2004-2009

Journal article

Skinner SJ, Feist JP, Brooks IJE, Seefeldt S, Heyes ALet al., 2009, YAG:YSZ composites as potential thermographic phosphors for high temperature sensor applications, SENSORS AND ACTUATORS B-CHEMICAL, Vol: 136, Pages: 52-59, ISSN: 0925-4005

Journal article

Feist JP, Heyes AL, 2009, Photo-Stimulated Phosphorescence for Thermal Condition Monitoring and Nondestructive Evaluation in Thermal Barrier Coatings, 10th United Kingdom Heat Transfer Conference, Publisher: TAYLOR & FRANCIS INC, Pages: 1087-1095, ISSN: 0145-7632

Conference paper

McGlashan NR, PRN C, Heyes AL, Marquis AJet al., 2009, PRODUCING HYDROGEN AND POWER USING CHEMICAL LOOPING COMBUSTION AND WATER-GAS SHIFT. ASME Paper GT2009-59492, 54th ASME Turbo Expo 2009, Publisher: AMER SOC MECHANICAL ENGINEERS, Pages: 177-188

A cycle capable of generating both hydrogen and power with 'inherent' carbon capture is proposed and evaluated The cycle uses chemical looping combustion (CLC) to perform the primary energy release from a hydrocarbon, producing an exhaust of CO This CO is mixed with steam and converted to H-2 and CO2 using the water-gas shift reaction (WGSR).Chemical looping uses two reactions with a re-circulating oxygen carrier to oxidise hydrocarbons. The resulting oxidation and reduction stages are preformed in separate reactors the oxidiser and reducer respectively, and this partitioning facilitates CO2 capture. In addition, by careful selection of the oxygen carrier, the equilibrium temperature of both redox reactions can be reduced to values below the current industry standard metallurgical limit for gas turbines. This means that the irreversibility associated with the combustion process can be reduced significantly, leading to a system of enhanced overall efficiency. The choice of oxygen carrier also affects the ratio of CO vs. CO2 in the reducer's flue gas, with some metal oxide reduction reactions generating almost pure CO. This last feature is desirable if the maximum H-2 production is to be achieved using the WGSR reaction.Process flow diagrams of one possible embodiment using a zinc based oxygen carrier are presented. To generate power, the chemical looping system is operated as part of a gas turbine cycle, combined with a bottoming steam cycle to maximise efficiency. The WGSR supplies heat to the bottoming steam cycle, as well as helping to raise the steam necessary to complete the reaction. A mass and energy balance of the chemical looping system, the WGSR reactor, steam bottoming cycle and balance of plant, is presented and discussed. The results of this analysis show that the overall efficiency of the complete cycle is dependant on the operating pressure in the oxidiser, and under optimum conditions, exceeds 75%.

Conference paper

Bearman P, Heyes AL, Lear C, Smith DARet al., 2007, Evolution of a forced counter rotating vortex pair for two selected forcing frequncies, Experiments in Fluids, Vol: 43

Journal article

McGlashan NR, Heyes AL, Marquis AJ, 2007, Carbon Capture and Reduced Irreversibility Combustion Using Chemical Looping: GT2007-28116, ASME Turbo Expo 2007, Publisher: ASME, Pages: 429-439

Power generation traditionally depends on combustion to,release' the energy contained in fuels. Combustion is, however, an irreversible process and typically accounts for a quarter to a third of the lost work generation in power producing systems. The source of this irreversibility is the large departure from chemical equilibrium that occurs during the combustion of hydrocarbons. Chemical looping combustion (CLC) is a technology initially proposed as a means to reduce the lost work generation in combustion equipment. However, renewed interest has been shown in the technology since it also facilitates carbon capture.CLC works by replacing conventional "oxy-fuel" combustion with a two-step process. In the first, a suitable oxygen carrier (typically a metal) is oxidised using air. This results in an oxygen depleted air stream and a stream of metal oxide. The latter is then reduced in the second reaction step using a hydrocarbon fuel. The products of this second step are a stream of reduced metal, which is returned to the oxidation reaction, and a stream Of CO2 and H2O that can be separated easily. The thermodynamic benefits of CLC stem from the fact that the oxygen carrier is recirculated and can thus be chosen with a reasonable degree of freedom. This enables the chemistry to be optimised to reduce the lost work generation in the two reactors - the reactions can then be operated much closer to chemical equilibrium.It is widely accepted in the literature that a key issue in CLC is identifying the most effective oxygen carrier. However, most previous work appears to consider systems in which a solid phase metallic oxygen carrier is recirculated between two fluidised bed reactors. In the current paper, we explore the possibility of using liquid or gas phase reactions in the two reaction steps since it is hypothesised that these might be compatible with a wider range of fuels including coal. The paper, however, starts by reviewing the existing literature on CLC

Conference paper

Heyes AL, Feist JP, Chen X, Mutasim Z, Nicholls JRet al., 2007, Optical non-destructive condition monitoring of TBC's, 52nd ASME Turbo Expo 2007, Publisher: AMER SOC MECHANICAL ENGINEERS, Pages: 323-332

Conference paper

Heyes AL, Seefeldt S, Feist JP, 2006, Two-colour phosphor thermometry for surface temperature measurement, Colour and Design Conference, Publisher: ELSEVIER SCI LTD, Pages: 257-265, ISSN: 0030-3992

Conference paper

Bearman P, Heyes A, Lear C, Smith Det al., 2006, Natural and forced evolution of a counter rotating vortex pair, EXPERIMENTS IN FLUIDS, Vol: 40, Pages: 98-105, ISSN: 0723-4864

Journal article

Heyes AL, Smith DAR, 2005, Modification of a wing tip vortex by vortex generators, AEROSPACE SCIENCE AND TECHNOLOGY, Vol: 9, Pages: 469-475, ISSN: 1270-9638

Journal article

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