Performance Evaluation of a Catalytic Flat Plate Fuel Reformer for Hydrogen-Rich Reformate

2013 ◽  
Author(s):  
Susanta K. Das ◽  
K. Joel Berry
Keyword(s):  
Flat Plate ◽  
Reaction Rates ◽  
Operating Conditions ◽  
Design Parameters ◽  
Practical Implementation ◽  
Channel Height ◽  
Inlet Temperature ◽  
Optimized Design ◽  
Two Dimensional ◽  
Transfer Coefficients

A two-dimensional computational fluid dynamics (CFD) model is used for reforming methane with the help of catalytic combustion and reformation in a catalytic flat plate reformer. The two-dimensional approach makes the computational model more realistic by eliminating the uncertainties introduced by heat and mass transfer coefficients used in one-dimensional models. It also increased its capability to capture the effect of design parameters such as catalyst thickness, reaction rates, inlet temperature and velocity, and channel height has on producing high purity reformate gas. In order to carry out parametric studies related to various design parameters, in our present work, we simulate the entire flat plate reformer domain by considering full electro-kinetics that provide guidance for the practical implementation of such design. We chose different designs and operating conditions in such a way which makes possible to build a catalytic flat plate fuel reformer prototype. Based on the CFD results obtained in this study, we built a first generation catalytic flat plate fuel reformer prototype using the optimized design parameters. The performance of the fuel reformer prototype is tested with a 5-cell high temperature PEM fuel cell stack.

Modeling of a Catalytic Flat Plate Fuel Reformer for Hydrogen-Rich Reformate Fuel

2013 ◽  
Author(s):  
Susanta K. Das ◽  
Kranthi K. Gadde
Keyword(s):  
Flat Plate ◽  
Catalytic Combustion ◽  
Reaction Rates ◽  
Operating Conditions ◽  
Design Parameters ◽  
Practical Implementation ◽  
Channel Height ◽  
Inlet Temperature ◽  
Optimized Design ◽  
Two Dimensional

In this study, using a two-dimensional computational fluid dynamics (CFD) model with co-current flow arrangement, steam reforming of methane coupled with methane catalytic combustion in a catalytic plate reactor is investigated. The two-dimensional approach makes the model more realistic by increasing its capability to capture the effect of design parameters such as catalyst thickness, reaction rates, inlet temperature and velocity, and channel height, and eliminates the uncertainties introduced by heat and mass transfer coefficients used in one-dimensional models. In our work, we simulate the entire flat plate reformer electro-kinetics and carry out parametric studies related to design matrices that can provide guidance for the practical implementation of such design. The operating conditions are chosen in such a way which makes possible a good comparison of the catalytic plate reactor and catalytic combustion analysis with the conventional steam reformer. The CFD results obtained in this study is very helpful to understand the optimized design parameters to build a first generation prototype.

CFD Modeling of a Catalytic Flat Plate Fuel Reformer for Hydrogen Generation

2010 ◽  
Author(s):  
Kranthi K. Gadde ◽  
Panini K. Kolavennu ◽  
Susanta K. Das ◽  
K. J. Berry
Keyword(s):  
Flat Plate ◽  
Catalytic Combustion ◽  
Reaction Rates ◽  
Operating Conditions ◽  
Cfd Modeling ◽  
Design Parameters ◽  
Practical Implementation ◽  
Channel Height ◽  
Inlet Temperature ◽  
Two Dimensional

In this study, steam reforming of methane coupled with methane catalytic combustion in a catalytic plate reactor is studied using a two-dimensional mathematical model for co-current flow arrangement. A two-dimensional approach makes the model more realistic by increasing its capability to capture the effect of parameters such as catalyst thickness, reaction rates, inlet temperature and velocity, and channel height, and eliminates the uncertainties introduced by heat and mass transfer coefficients used in one-dimensional models. In our work, we simulate the entire flat plate reformer (both reforming side and combustion side) and carry out parametric studies related to channel height, inlet velocities, and catalyst layer thickness that can provide guidance for the practical implementation of such design. The operating conditions chosen make possible a comparison of the catalytic plate reactor and catalytic combustion analysis with the conventional steam reformer. The CFD results obtained in this study will be very helpful to understand the optimization of design parameters to build a first generation prototype.

Experimental Performance Evaluation of a Catalytic Flat Plate Fuel Reformer for Fuel Cell Grade Reformate

2014 ◽  
Author(s):  
Susanta K. Das ◽  
K. Joel Berry
Keyword(s):  
Fuel Cell ◽  
Flat Plate ◽  
Reaction Rates ◽  
Design Parameters ◽  
Channel Height ◽  
Inlet Temperature ◽  
Cfd Model ◽  
Current Voltage ◽  
Study Results ◽  
Current Voltage Characteristics

Compact and efficient fuel reforming system design is a major challenge because of strict requirements of efficient heat distribution on both the reforming and combustion side. As an alternative to traditional packed bed tubular reformers, catalytic flat plate fuel reformer offers better heat integration by combining the combustion reaction on one side and reforming reaction on the other side. In this study, with the help of a two-dimensional computational fluid dynamics (CFD) model, a catalytic flat plate fuel reformer is built and investigated its performance experimentally. The CFD model simulation results help to capture the effect of design parameters such as catalyst layer thickness, reaction rates, inlet temperature and velocity, and channel height. The CFD model study results also help to design and built the actual reformer in such a way that eliminate the limitations or uncertainties of heat and mass transfer coefficients. In our study, we experimentally evaluated the catalytic flat plate fuel reformer performance using natural gas. The effect of reformate gas on the current-voltage characteristics of a 5kW high temperature PEM fuel cell (HTPEMFC) stack is investigated extensively. The results shows that the overall system performance increases in terms of current-voltage characteristics of HTPEMFC while fed with reformate directly from the catalytic flat plate reformer.

Computational Fluid Dynamics Modeling of a Catalytic Flat Plate Fuel Reformer for On-Board Hydrogen Generation

2013 ◽  
Vol 10 (6) ◽  
Author(s):  
Susanta K. Das ◽  
Kranthi K. Gadde
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Flat Plate ◽  
Catalytic Combustion ◽  
Cocurrent Flow ◽  
Design Parameters ◽  
Practical Implementation ◽  
Channel Height ◽  
Two Dimensional ◽  
Wgs Reaction

A catalytic flat plate fuel reformer offers better heat integration by combining the exothermic catalytic combustion reaction on one side and the endothermic catalytic reforming reaction on the other side. In this study, steam reforming of natural gas (methane) coupled with a methane catalytic combustion in a catalytic flat plate reformer is studied using a two-dimensional model for a cocurrent flow arrangement. The two-dimensional computational fluid dynamics (CFD) model makes the predictions more realistic by increasing its capability to capture the effect of various design parameters and eliminates the uncertainties introduced by heat and mass transfer coefficients used in one-dimensional models. In our work we simulated the entire catalytic flat plate reformer (both reforming side and combustion side) and carried-out studies related to important design parameters such as channel height, inlet fuel velocities, and catalyst layer thickness that can provide guidance for the practical implementation of such fuel reformer design. The simulated transverse temperature profiles (not shown here due to page limitation) show that there is virtually no heat loss across the plate at the reformer exit. Introduction of a water gas shift (WGS) reaction at the reformer side along with our optimized reformer design parameters decreases the amount of carbon monoxide (CO) almost 90%–98% in the final reformate exiting the reformer as compared to without the WGS reaction. The CFD results obtained in this study will be very helpful to understand the optimization of design parameters to build a first generation prototype.

Transient Considerations of Flat-Plate Solar Collectors

1974 ◽  
Vol 96 (2) ◽  
pp. 109-113 ◽  
Author(s):  
S. A. Klein ◽  
J. A. Duffie ◽  
W. A. Beckman
Keyword(s):  
Flat Plate ◽  
Solar Collector ◽  
Meteorological Data ◽  
Weather Conditions ◽  
Operating Conditions ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Thermal Capacitance ◽  
Flat Plate Solar Collector ◽  
Capacitance Effects

The effects of thermal capacitance in the modeling of the performance of a flat plate solar collector have often been neglected because of the computation involved. But because the solar collector is inherently exposed to continuously variable weather conditions, capacitance effects may be significant. To investigate these effects, three different models of flat-plate collectors have been investigated. The first, a quasi-steady-state model, simulates the performance of a collector of zero capacitance. The second model accounts for capacitance effects by assuming that a single value of thermal capacitance can be determined for the collector as a unit. The third model divides the collector into many isothermal segments, or nodes. For all three models the heat transfer coefficients are calculated as a function of operating conditions. The results show that, when hourly meteorological data are used, the zero-capacitance model is adequate.

Heat Transfer Characteristics of Impinging Two-Dimensional Air Jets

1966 ◽  
Vol 88 (1) ◽  
pp. 101-107 ◽  
Author(s):  
Robert Gardon ◽  
J. Cahit Akfirat
Keyword(s):  
Heat Transfer ◽  
Flat Plate ◽  
Two Dimensional ◽  
Heat Transfer Characteristics ◽  
Transfer Coefficients ◽  
Average Heat ◽  
Heat Transfer Coefficients ◽  
Transfer Characteristics ◽  
Air Jets

Local as well as average heat transfer coefficients between an isothermal flat plate and impinging two-dimensional jets were measured for both single jets and arrays of jets. For a large and technologically important range of variables the results have been correlated in relatively simple terms, and their application to design is briefly considered.

An Experimental Study of Combustor Exit Profile Shapes on Endwall Heat Transfer in High Pressure Turbine Vanes

2009 ◽  
Vol 131 (2) ◽  
Author(s):  
M. D. Barringer ◽  
K. A. Thole ◽  
M. D. Polanka
Keyword(s):  
Heat Transfer ◽  
High Pressure ◽  
Elevated Temperatures ◽  
Convection Heat Transfer ◽  
Operating Conditions ◽  
Inlet Temperature ◽  
Transfer Coefficients ◽  
High Pressure Turbine ◽  
Radial Profiles ◽  
Temperature And Pressure

The design and development of current and future gas turbine engines for aircraft propulsion have focused on operating the high pressure turbine at increasingly elevated temperatures and pressures. The drive toward thermal operating conditions near theoretical stoichiometric limits as well as increasingly stringent requirements on reducing harmful emissions both equate to the temperature profiles exiting combustors and entering turbines becoming less peaked than in the past. This drive has placed emphasis on determining how different types of inlet temperature and pressure profiles affect the first stage airfoil endwalls. The goal of the current study was to investigate how different radial profiles of temperature and pressure affect the heat transfer along the vane endwall in a high pressure turbine. Testing was performed in the Turbine Research Facility located at the Air Force Research Laboratory using an inlet profile generator. Results indicate that the convection heat transfer coefficients are influenced by both the inlet pressure profile shape and the location along the endwall. The heat transfer driving temperature for inlet profiles that are nonuniform in temperature is also discussed.

Performance Analyses of Photovoltaic Thermal Integrated Concentrator Collector Combined With Single Effect Absorption Cooling Cycle: Constant Flow Rate Mode

2020 ◽  
Vol 142 (12) ◽  
Author(s):  
Md. Meraj ◽  
M.E. Khan ◽  
Md. Azhar
Keyword(s):  
Climatic Conditions ◽  
Operating Conditions ◽  
Coefficient Of Performance ◽  
Design Parameters ◽  
Inlet Temperature ◽  
New Delhi ◽  
Absorption System ◽  
Simulation Code ◽  
Single Effect ◽  
Performance Analyses

Abstract In the present communication, performance analyses of interconnected N number of fully covered semitransparent photovoltaic thermal integrated concentrator collectors combined with single effect vapor absorption refrigeration system have been carried out. The proposed system was analyzed under the constant mass flowrate of collectors’ fluid. Mathematical expressions have also been derived for generator temperature of the absorption unit as a function of both design and operating parameters. Further, simulations have been performed for a typical day of May month of New Delhi climatic conditions. Performance parameters have been evaluated such as collector exit temperature, generator inlet temperature, electrical power output, electrical efficiency, overall thermal energy gain, instantaneous thermal efficiency, overall exergy gain and coefficient of performance of the absorption system. The simulation code has been written in matlab. From the present analyses, the following salient conclusions have been drawn: Operating generator temperature of the absorption system is suitable for five number of photovoltaic thermal-integrated parabolic concentrator collector connected in series. The proposed system will continue operating for 5 h during May month in New Delhi climate conditions. The maximum solar coefficient of performance, refrigeration coefficient of performance, and exergy coefficient of performance are reported as 0.1551, 0.8344, and 0.2697, respectively, for the proposed novel system under given design and operating conditions. Additionally, the effects of other design parameters of this novel system have also been investigated.

An Experimental Study of Combustor Exit Profile Shapes on Endwall Heat Transfer in High Pressure Turbine Vanes

2007 ◽  
Author(s):  
M. D. Barringer ◽  
M. D. Polanka ◽  
K. A. Thole
Keyword(s):  
Heat Transfer ◽  
High Pressure ◽  
Elevated Temperatures ◽  
Convection Heat Transfer ◽  
Operating Conditions ◽  
Inlet Temperature ◽  
Transfer Coefficients ◽  
High Pressure Turbine ◽  
Radial Profiles ◽  
Temperature And Pressure

The design and development of current and future gas turbine engines for aircraft propulsion have focused on operating the high pressure turbine at increasingly elevated temperatures and pressures. The drive towards thermal operating conditions near theoretical stoichiometric limits as well as increasingly stringent requirements on reducing harmful emissions, both equate to the temperature profiles exiting combustors and entering turbines becoming less peaked than in the past. This drive has placed emphasis on determining how different types of inlet temperature and pressure profiles affect the first stage airfoil endwalls. The goal of the current study was to investigate how different radial profiles of temperature and pressure affect the heat transfer along the vane endwall in a high pressure turbine. Testing was performed in the Turbine Research Facility located at the Air Force Research Laboratory using an inlet profile generator. Results indicate that the convection heat transfer coefficients are influenced by both the inlet pressure profile shape and the location along the endwall. The heat transfer driving temperature for inlet profiles that are non-uniform in temperature is also discussed.

scholarly journals Investigation of the thermal effect of a tubular permanent magnet actuator with a water cooling channel for active lateral suspension of a high-speed train

2019 ◽  
Vol 11 (3) ◽  
pp. 168781401881966
Author(s):  
Dong-wook Kim ◽  
Jung-Hyun Woo ◽  
Kyoung-Su Park
Keyword(s):  
Permanent Magnet ◽  
High Speed ◽  
Ride Comfort ◽  
Cooling System ◽  
Operating Conditions ◽  
Design Parameters ◽  
Water Cooling ◽  
Transfer Coefficients ◽  
Permanent Magnet Actuator ◽  
Water Cooling System

Worldwide, high-speed rail is becoming an increasingly popular and efficient means of transport. However, increasing the speed of a train leads to major reductions in stability and ride comfort. Here, we develop a tubular permanent magnet actuator to overcome these problems. To increase actuator thrust, the electromagnetic circuit requires a high current and, thus, becomes hot. We use a water cooling system with 12 straight copper channels to reduce the temperature. We calculate heat transfer coefficients using empirical convection correlations between laminar flow in the channels and experimental results. The predicted, tube surface temperatures correlated well with the experimental data. We evaluated the effects of flow rate and initial water temperature on various design parameters. The cooling system allowed application of a current greater than 100 A, developing a thrust force of over 8000 N. Thus, the system was robust under harsh operating conditions. We measured the thrust and cogging forces and the performance of the water cooling system in terms of the maximum acceptable temperature. The thrust was high and the cogging torque was low, greatly reducing lateral vibration; the temperature remained below the acceptable maximum.

Sign in / Sign up

Export Citation Format

Share Document