Operational Characteristic of Planar Steam Reformer Thermally Coupled With Catalytic Burner

2012 ◽  
Author(s):  
Kanghun Lee ◽  
Sangseok Yu ◽  
Sang gyu Kang ◽  
Kook Young Ahn ◽  
Sang Min Lee
Keyword(s):  
High Efficiency ◽  
Volume Fraction ◽  
Longitudinal Direction ◽  
Cell System ◽  
Geometric Constraints ◽  
Inlet Temperature ◽  
Operational Characteristic ◽  
Steam Reformer ◽  
Catalytic Burner ◽  
Catalytic Combustor

High efficiency reforming is a key parameter of high temperature stationary fuel cell system. In this study, a planar heat exchanger steam reformer (PHESR) was integrated with catalytic combustor in order that the unused energy of anode off-gas is delivered for heat of reforming. The PHESR was designed to use the anode-off gas of externally reformed SOFC system because it has an efficiency problem. In the PHESR reactor, the heat is transferred from catalytic burner to reformer that has weak gradient of temperature difference between two reactors. The thermal behaviors of exothermic and endothermic reactions between reactors were investigated experimentally. The parameters of investigation were fuel utilization, inlet temperature, and air excess ratio. Comparison parameter was volume fraction of hydrogen at the exit of reforming side. The temperature gradients in longitudinal direction of two reactors were measured. As expected, temperature differences between two reactors were crucial factors that required optimization. Furthermore, the geometric aspects between the finned and un-finned reactors were also investigated. The results demonstrate that the volume fraction of hydrogen at the exit is closely coupled with the geometric constraints and the operating parameters.

scholarly journals Status of the European Gas Turbine Program — AGATA

1998 ◽  
Author(s):  
Rolf Gabrielsson ◽  
Robert Lundberg ◽  
Patrick Avran
Keyword(s):  
Steady State ◽  
Heat Exchanger ◽  
Gas Turbine ◽  
Hybrid Electric Vehicle ◽  
High Efficiency ◽  
Full Scale ◽  
Inlet Temperature ◽  
Turbine Wheel ◽  
Ceramic Components ◽  
Catalytic Combustor

The European Gas Turbine Program “AGATA” which started in 1993 now has reached its verification phase. The objective of the program is to develop three critical ceramic components aimed at a 60 kW turbogenerator in a hybrid electric vehicle — a catalytic combustor, a radial turbine wheel and a static heat exchanger. The AGATA partners represent car manufacturers as well as companies and research institutes in the turbine, catalyst and ceramic material fields in both France and Sweden. Each of the three ceramic components is validated separately during steady state and transient conditions in separate test rigs at ONERA, France, where the high pressure/temperature conditions can be achieved. A separate test rig for laser measurements downstream of the catalytic combustor is set up at Volvo Aero Turbines, Sweden. The catalytic combustor design which includes preheater, premix duct and catalytic section operates at temperatures up to 1623 K. Due to this high temperature, the catalyst initially has undergone pilot tests including ageing, activity and strength tests. The premix duct flow field also has been evaluated by LDV measurements. The full scale combustion tests are ongoing. The turbine wheel design is completed and the first wheels have been manufactured. FEM calculations have indicated that stress levels are below 300 MPa. The material used is a silicon nitride manufactured by AC Cerama (Grade CSN 101). Cold spin tests with complete wheels have started. Hot spin tests at TTT 1623 K will be performed in a modified turbo charger rig and are expected to start in February 1998. The heat exchanger is of a high efficiency plate recuperator design using Cordierite material. Hot side inlet temperature is 1286 K. Therefore initial tests with test samples have been run to evaluate the thermomechanical properties at high temperatures. Tests are now proceeding with a 1/4 scale recuperator prototype to evaluate performance at steady state conditions. Manufacturing of the full scale heat exchanger is now in progress.

scholarly journals Catalytic Combustor Development Within the AGATA Program

1999 ◽  
Author(s):  
Rolf Gabrielsson ◽  
Gerard Payen ◽  
Patrick Avran
Keyword(s):  
High Temperature ◽  
Hybrid Electric Vehicle ◽  
High Efficiency ◽  
Gas Analysis ◽  
Full Scale ◽  
Inlet Temperature ◽  
Turbine Wheel ◽  
Catalytic Material ◽  
Catalytic Combustor ◽  
Maximum Design

The European AGATA programme (Advanced Gas Turbine for Automobiles), is a programme dedicated to the development of three critical ceramic components — a catalytic combustor, a radial turbine wheel and a static heat exchanger — for a 60 kW turbogenerator in a hybrid electric vehicle. These three components, which are of critical importance to the achievement of low emissions and high efficiency, have been designed, developed, manufactured and tested as part of a full-scale feasibility study. The AGATA partners represent car manufacturers as well as companies and research institutes in the turbine, catalyst and ceramic material fields in both France and Sweden. The AGATA project commenced in early 1993 and has occupied a 5-year period until April 1998. This paper summarises the results from the development of the catalytic combustor. The catalytic combustor operates at temperatures in the catalytic section from inlet 935°C to the exhaust 1350°C. Therefore all structural components in the hot section are made of ceramic materials. The testing and validation have been run through a component test campaign from which it was concluded that: • The catalytic section substrates showed good behaviour during the high temperature tests. • Palladium was chosen as the active catalytic material after extensive testing at pilot scale. Ageing at high temperature (1270°C) has a strong effect on catalyst deactivation. • Emissions levels of the preheater are in agreement with the state of the an for small aero-engines according to the ICAO legislation. The complete full scale combustor testing was run in the following steps: • Initial gas analysis tests at inlet temperature 200° lower than the nominal value • CARS and gas analysis • Comparison diesel and ethanol fuels • Final testing at maximum design temperatures and pressure The catalytic combustor was run on diesel fuel during the complete test period. A test campaign comparing exhaust emissions when running on ethanol fuel was performed at Volvo Aero Turbines. These results showed that the catalyst reaction rate and CO/HC/NOx emissions were similar. This means that the chosen catalytic combustor can be used as a dual fuel combustor diesel/ethanol. The final test campaign at ONERA, France, was run up to temperatures slightly above the specified maximum design temperatures. Inlet temperature 962°C (design 935°C) and exhaust temperature 1362°C (design 1350°C). These tests showed that NOx emission levels below 4 ppm @15% O2 were obtained when low CO and HC emissions levels were measured at full load conditions. This promising performance level was reached with technologies that still have to be thoroughly evaluated in terms of durability and low cost potential for industrial applications.

scholarly journals Design and Empirical Inquisition of Catalytic Combustor for Methanol Steam Reformer in HT-PEM Fuel Cell Systems

2020 ◽  
Vol 9 (4) ◽  
pp. 1776-1783
Keyword(s):  
Fuel Cell ◽  
Active Sites ◽  
Operating Temperature ◽  
Pem Fuel Cell ◽  
Packed Bed ◽  
Cell System ◽  
Normal Operation ◽  
Water Mixture ◽  
Steam Reformer ◽  
Catalytic Combustor

Steam reforming of methanol is a basic endothermic reaction. For which, a separate external system is required for generation of heat. The reaction speeds are controlled by operating temperature and heat transfer rate to the reactor. This operating temperature has a very narrow window of operation. It is therefore extremely important to have a system that generates controlled combustion based stable heat for providing required heat to reformer. A design of catalytic combustor was developed and analyzed for methanol steam reformer. The packed bed of combustion catalyst provides active sites for combustion of the methanol water mixture during start-up and later for combustion of anode exhaust gas (AEG) during normal operation. The combustion reactions and their thermodynamics were studied for commercial catalyst. System design was simulated using Engineering Equation Solver (EES) software for determining the quantity of air required for combustion of fuel as well as for dilution of gases to maintain a temperature of 573 K. The design was analyzed using ANSYS DISCOVERY LIVE for understanding the different operating condition(s) inside the combustor. It was also used to generate design of experiments to evaluate, build and demonstrate a catalytic combustor for on-board reformer for HT-PEM fuel cell system.

Development of a coupled reactor with a catalytic combustor and steam reformer for a 5 kW solid oxide fuel cell system

2014 ◽  
Vol 114 ◽  
pp. 114-123 ◽  
Author(s):  
Sanggyu Kang ◽  
Kanghun Lee ◽  
Sangseok Yu ◽  
Sang Min Lee ◽  
Kook-Young Ahn
Keyword(s):  
Fuel Cell ◽  
Solid Oxide Fuel Cell ◽  
Cell System ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Fuel Cell System ◽  
Steam Reformer ◽  
Catalytic Combustor

A Reforming Characteristics of a Mid-Temperature Methane-Steam Reformer With Various Configurations

2018 ◽  
Author(s):  
Kyungin Cho ◽  
Jinwon Yun ◽  
Sangseok Yu
Keyword(s):  
High Temperature ◽  
Fuel Cell ◽  
Heat Source ◽  
Cell System ◽  
Inlet Temperature ◽  
System Efficiency ◽  
Fuel Cell System ◽  
Steam Reformer ◽  
Methane Steam ◽  
Reforming Catalyst

A external methane-steam reformer is applied to fuel delivery of high temperature fuel cell system. When the reformer is equipped for high temperature fuel cell system, the heat supply of the methane steam reformer is critical to improve the system efficiency. Typically, system efficiency is improved as the waste heat is utilized. However, the general performance of steam reformer is designed to provide the rated performance at high temperature. In this study, characteristics of mid-temperature steam reformer are investigated. At mid-temperature operation of steam reformer, it is important to understand the performance of the reformer include inlet flow rate, temperature, and reformer geometry, and so on. Among them, the characteristics of the reforming catalyst are the most fundamental and most important in the performance of the reformer. Also, it is possible to optimize the performance of the reformer by understanding the reforming rate depending on the reformer inlet temperature, the amount of heat source, and the SCR (Steam to Carbon Ratio). Therefore, experimental study was carried out to understand the characteristics of the reforming catalyst. In order to carry out the experiment, the length of the reformer and the number of the heat source tubes were made variously so that the performance characteristics according to the volume of the reforming catalyst layer were confirmed. Through analysis of the experimental results, the characteristics of the reforming catalyst, which is an important factor in the performance of the reformer, can be understood under various conditions.

Modeling a Catalytic Combustor for a Steam Reformer in a Methanol Fuel Cell Vehicle

2000 ◽  
Author(s):  
Meena Sundaresan ◽  
Sitaram Ramaswamy ◽  
Robert M. Moore
Keyword(s):  
Fuel Cell ◽  
Proton Exchange Membrane ◽  
Proton Exchange ◽  
Fuel Cell Vehicle ◽  
Pure Hydrogen ◽  
Steam Reformer ◽  
Fuel Processor ◽  
Catalytic Burner ◽  
Catalytic Combustor ◽  
Exchange Membrane

Abstract Using a fuel other than pure hydrogen in a fuel cell vehicle (FCV) employing a Proton Exchange Membrane (PEM) fuel cell stack typically requires an on-board fuel processor to provide hydrogen-rich fuel to the stack. In the case of methanol as the source fuel, the reformation process typically occurs in a fuel processor that combines a steam reformer plus a catalytic burner (to provide the necessary energy for the endothermic steam reforming reactions to occur). This paper will discuss a model for the catalytic burner in a methanol fuel processor for an Indirect Methanol FCV. The model uses MATLAB/Simulink software and the simulation provides results for both energy efficiency and pollutant formation.

scholarly journals Effects of SiC Fibers and Laminated Structure on Mechanical Properties of Ti–Al Laminated Composites

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1323
Author(s):  
Chenyang Hou ◽  
Shouyin Zhang ◽  
Zhijian Ma ◽  
Baiping Lu ◽  
Zhenjun Wang
Keyword(s):  
Volume Fraction ◽  
Raw Materials ◽  
Laminated Composites ◽  
Intermetallic Layer ◽  
Longitudinal Direction ◽  
Fracture Mechanisms ◽  
Compact Structure ◽  
Laminated Structure ◽  
Sic Fibers ◽  
Sic Fiber

Ti/Ti–Al and SiCf-reinforced Ti/Ti–Al laminated composites were fabricated through vacuum hot-pressure using pure Ti foils, pure Al foils and SiC fibers as raw materials. The effects of SiC fiber and a laminated structure on the properties of Ti–Al laminated composites were studied. A novel method of fiber weaving was implemented to arrange the SiC fibers, which can guarantee the equal spacing of the fibers without introducing other elements. Results showed that with a higher exerted pressure, a more compact structure with fewer Kirkendall holes can be obtained in SiCf-reinforced Ti/Ti–Al laminated composites. The tensile strength along the longitudinal direction of fibers was about 400 ± 10 MPa, which was 60% higher compared with the fabricated Ti/Ti–Al laminated composites with the same volume fraction (60%) of the Ti layer. An in situ tensile test was adopted to observe the deformation behavior and fracture mechanisms of the SiCf-reinforced Ti/Ti–Al laminated composites. Results showed that microcracks first occurred in the Ti–Al intermetallic layer.

scholarly journals Performance improvement of double-tube gas cooler in CO2 refrigeration system using nanofluids

2015 ◽  
Vol 19 (1) ◽  
pp. 109-118 ◽  
Author(s):  
Jahar Sarkar
Keyword(s):  
Performance Improvement ◽  
Volume Fraction ◽  
Particle Volume Fraction ◽  
Cooling Capacity ◽  
Inlet Temperature ◽  
Refrigeration Cycle ◽  
Particle Volume ◽  
Transcritical Carbon Dioxide ◽  
The Given ◽  
Theoretical Analyses

The theoretical analyses of the double-tube gas cooler in transcritical carbon dioxide refrigeration cycle have been performed to study the performance improvement of gas cooler as well as CO2 cycle using Al2O3, TiO2, CuO and Cu nanofluids as coolants. Effects of various operating parameters (nanofluid inlet temperature and mass flow rate, CO2 pressure and particle volume fraction) are studied as well. Use of nanofluid as coolant in double-tube gas cooler of CO2 cycle improves the gas cooler effectiveness, cooling capacity and COP without penalty of pumping power. The CO2 cycle yields best performance using Al2O3-H2O as a coolant in double-tube gas cooler followed by TiO2-H2O, CuO-H2O and Cu-H2O. The maximum cooling COP improvement of transcritical CO2 cycle for Al2O3-H2O is 25.4%, whereas that for TiO2-H2O is 23.8%, for CuO-H2O is 20.2% and for Cu-H2O is 16.2% for the given ranges of study. Study shows that the nanofluid may effectively use as coolant in double-tube gas cooler to improve the performance of transcritical CO2 refrigeration cycle.

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