A Modular Ceramic Cavity-Receiver for High-Temperature High-Concentration Solar Applications

2011 ◽  
Vol 134 (1) ◽  
Author(s):  
I. Hischier ◽  
P. Poživil ◽  
A. Steinfeld
Keyword(s):  
High Temperature ◽  
Material Properties ◽  
Gas Turbines ◽  
Power Input ◽  
Model Coupling ◽  
Transfer Model ◽  
High Concentration ◽  
Compound Parabolic Concentrator ◽  
Radiative Power ◽  
Reflective Coatings

A high-temperature pressurized air-based receiver is considered as a module for power generation via solar-driven gas turbines. A set of silicon carbide cavity-receivers attached to a compound parabolic concentrator (CPC) are tested on a solar tower at stagnation conditions for 35 kW solar radiative power input under mean solar concentration ratios of 2000 suns and nominal temperatures up to 1600 K. A heat transfer model coupling radiation, conduction, and convection is formulated by Monte Carlo ray-tracing, finite volume, and finite element techniques, and validated in terms of experimentally measured temperatures. The model is applied to elucidate the effect of material properties, geometry, and reflective coatings on the cavity’s thermal and structural performances.

Modular Design and Experimental Testing of a 50 kWth Pressurized-Air Solar Receiver for Gas Turbines

2015 ◽  
Vol 137 (3) ◽  
Author(s):  
Peter Poživil ◽  
Nicolas Ettlin ◽  
Fabian Stucker ◽  
Aldo Steinfeld
Keyword(s):  
Gas Turbines ◽  
Modular Design ◽  
Experimental Testing ◽  
Porous Ceramic ◽  
Power Input ◽  
Absolute Pressure ◽  
High Concentration ◽  
Air Temperatures ◽  
Radiative Power ◽  
Solar Receiver

A high-temperature high-concentration pressurized-air solar receiver is considered for driving a power generation Brayton cycle. The modular design consists of a cylindrical SiC cavity surrounded by a concentric annular reticulated porous ceramic (RPC) foam contained in a stainless steel pressure vessel, with a secondary concentrator attached to its windowless aperture. Experimentation was carried out in a solar tower for up to 47 kW of concentrated solar radiative power input in the absolute pressure range of 2-6 bar. Peak outlet air temperatures exceeding 1200 °C were reached for an average solar concentration ratio of 2500 suns. A notable thermal efficiency—defined as the ratio of the enthalpy change of the air flow divided by the solar radiative power input through the aperture—of 91% was achieved at 700 °C and 4 bar.

Advancement in Heated Spin Testing Technologies

2013 ◽  
Author(s):  
Hiroaki Endo ◽  
Robert Wetherbee ◽  
Nikhil Kaushal
Keyword(s):  
High Temperature ◽  
Gas Turbine ◽  
Material Properties ◽  
Gas Turbines ◽  
Multiple Scales ◽  
Thermal Conditions ◽  
Complex Stress ◽  
Operating Conditions ◽  
Mechanical Cycling ◽  
Testing Techniques

An ever more rapidly accelerating trend toward pursuing more efficient gas turbines pushes the engines to hotter and more arduous operating conditions. This trend drives the need for new materials, coatings and associated modeling and testing techniques required to evaluate new component design in high temperature environments and complex stress conditions. This paper will present the recent advances in spin testing techniques that are capable of creating complex stress and thermal conditions, which more closely represent “engine like” conditions. The data from the tests will also become essential references that support the effort in Integrated Computational Materials Engineering (ICME) and in the advances in rotor design and lifing analysis models. Future innovation in aerospace products is critically depended on simultaneous engineering of material properties, product design, and manufacturing processes. ICME is an emerging discipline with an approach to design products, the materials that comprise them, and their associated materials processing methods by linking materials models at multiple scales (Structural, Macro, Meso, Micro, Nano, etc). The focus of the ICME is on the materials; understanding how processes produce material structures, how those structures give rise to material properties, and how to select and/or engineer materials for a given application [34]. The use of advanced high temperature spin testing technologies, including thermal gradient and thermo-mechanical cycling capabilities, combined with the innovative use of modern sensors and instrumentation methods, enables the examination of gas turbine discs and blades under the thermal and the mechanical loads that are more relevant to the conditions of the problematic damages occurring in modern gas turbine engines.

Numerical Simulation of Heat Transfer in a 3D Cavity-Receiver

2015 ◽  
Author(s):  
Parthasarathy Pandi ◽  
Patrick Le Clercq
Keyword(s):  
Material Properties ◽  
Measurement Data ◽  
Power Input ◽  
Momentum Equation ◽  
Process Models ◽  
Conductive Heat ◽  
Recirculating Flow ◽  
Radiative Power ◽  
Ceria Reduction ◽  
Energy Equations

The unsteady 3D fluid flow coupled to radiative, convective, and conductive heat transfers are computed within a cavity-receiver that was successfully tested experimentally. A Monte-Carlo radiation model is used in the fluid regions of the reactor with source terms outside the cavity’s window to account for the concentrated radiative power input. Darcy’s law for the viscous regime and the Forchheimer’s term for the inertial regime are used in the momentum equation to account for the pressure drop within the porous region (RPC). Two separate energy equations for the solid and for the fluid regions of the porous domain are solved in order to capture the non-equilibrium effects in that region. Rosseland diffusion approximation is used in the solid regions of the RPC domain. The material properties and boundary conditions were taken from published experimental measurements. The simulation results are compared to the measurement data collected during the pre-heating and the ceria reduction phases, which sum up to four different radiative power inputs. Results of the comparison are very good and constitute the verification that the numerical methods, physical sub-process models and material properties are adequately selected and implemented. An analysis regarding the heat balance, the recirculating flow and, the effect of dual-scale porosity is also presented.

scholarly journals On the Potential of Power Generation from Thermoelectric Generators in Gas Turbine Combustors

Energies ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2769 ◽  
Author(s):  
Panagiotis Stathopoulos ◽  
Javier Fernàndez-Villa
Keyword(s):  
Power Generation ◽  
High Temperature ◽  
Gas Turbine ◽  
Film Cooling ◽  
Gas Turbines ◽  
Transfer Model ◽  
Thermoelectric Generators ◽  
Thermal Shield ◽  
Gas Turbine Combustors ◽  
Base Load

Thermoelectric generators (TEGs) offer an attractive power generation option. They have no moving parts, are robust and emit no pollutants. The current work explores the integration of high temperature TEGs in gas turbine combustors. The latter have a thermal shield at their inner surface to protect them against high temperatures. This is supplemented by convective and film cooling. This work studies the replacement of the thermal shield with high temperature TEGs and evaluates their techno-economic potential. A gas turbine model is developed and validated to compute the fuel and air flow rate in the combustion chamber. A heat transfer model is subsequently implemented to compute the temperature distribution inside the combustor wall, on which the TEG is constructed. The investment in TEGs is then analyzed for peaker, intermediate load and base load gas turbines. The work concludes with a sensitivity analysis of the investment economic performance. It is concluded that, despite the low power generation, the installation of TEGs makes economic sense, even if their price becomes 50% higher than current estimations. It is also concluded that electricity prices have a much stronger effect on the economic viability of the investment than the price of the generators.

Pilot Scale Demonstration of a 100-kWth Solar Thermochemical Plant for the Thermal Dissociation of ZnO

2013 ◽  
Vol 136 (1) ◽  
Author(s):  
W. Villasmil ◽  
M. Brkic ◽  
D. Wuillemin ◽  
A. Meier ◽  
A. Steinfeld
Keyword(s):  
High Temperature ◽  
Large Scale ◽  
Thermal Dissociation ◽  
Molar Fraction ◽  
Power Input ◽  
Pilot Scale ◽  
Radiative Fluxes ◽  
Gaseous Products ◽  
Solar Reactor ◽  
Radiative Power

A solar-driven thermochemical pilot plant for the high-temperature thermal dissociation of ZnO has been designed, fabricated, and experimentally demonstrated. Tests were conducted at the large-scale solar concentrating facility of PROMES-CNRS by subjecting the solar reactor to concentrated radiative fluxes of up to 4477 suns and peak solar radiative power input of 140 kWth. The solar reactor was operated at temperatures up to 1936 K, yielding a Zn molar fraction of the condensed products in the range 12–49% that was largely dependent on the flow rate of Ar injected to quench the evolving gaseous products.

JESSOP SAVILLE H.40

Alloy Digest ◽  
1963 ◽  
Vol 12 (1) ◽  
Keyword(s):  
Fracture Toughness ◽  
High Temperature ◽  
Physical Properties ◽  
Tensile Properties ◽  
Alloy Steel ◽  
Gas Turbines ◽  
Heat Treating ◽  
Temperature Performance

Abstract Jessop-Saville H.40 is an alloy steel recommended for high-temperature stressed components of gas turbines. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness, creep, and fatigue. It also includes information on high temperature performance as well as forming, heat treating, machining, and joining. Filing Code: SA-140. Producer or source: Jessop-Saville Ltd, Brightside Works.

scholarly journals Effect of material properties on heat transfer during cooling of high-temperature cylindrical bodies in liquids

2020 ◽  
Vol 1683 ◽  
pp. 032043
Author(s):  
I A Molotova ◽  
A R Zabirov ◽  
V V Yagov ◽  
M M Vinogradov ◽  
I A Belyaev
Keyword(s):  
Heat Transfer ◽  
High Temperature ◽  
Material Properties

An Improved Nickel Based MIMS Thermocouple for High Temperature Gas Turbine Applications

2012 ◽  
Author(s):  
Michele Scervini ◽  
Catherine Rae
Keyword(s):  
High Temperature ◽  
Gas Turbine ◽  
High Temperatures ◽  
Gas Turbines ◽  
Material Science ◽  
University Of Cambridge ◽  
Type K ◽  
Metallurgical Analysis ◽  
The University ◽  
High Temperature Gas

A new Nickel based thermocouple for high temperature applications in gas turbines has been devised at the Department of Material Science and Metallurgy of the University of Cambridge. This paper describes the new features of the thermocouple, the drift tests on the first prototype and compares the behaviour of the new sensor with conventional mineral insulated metal sheathed Type K thermocouples: the new thermocouple has a significant improvement in terms of drift and temperature capabilities. Metallurgical analysis has been undertaken on selected sections of the thermocouples exposed at high temperatures which rationalises the reduced drift of the new sensor. A second prototype will be tested in follow-on research, from which further improvements in drift and temperature capabilities are expected.

A Model for Predicting Temperature of Electrofusion Joints for Polyethylene Pipes

2009 ◽  
Vol 131 (6) ◽  
Author(s):  
Jianfeng Shi ◽  
Jinyang Zheng ◽  
Weican Guo ◽  
Ping Xu ◽  
Yongquan Qin ◽  
...  
Keyword(s):  
Thermal Contact ◽  
Power Input ◽  
Ultrasonic Test ◽  
Thermal Contact Conductance ◽  
Transfer Model ◽  
Contact Conductance ◽  
One Dimensional ◽  
Polyethylene Pipes ◽  
Heating Wire ◽  
Good Agreement

With the increasing application of electrofusion (EF) welding in connecting polyethylene (PE) pipes for gas distribution, more effort has been invested to ensure the safety of the pipeline systems. The objective of this paper is to investigate and understand the temperature distribution during EF welding. A one-dimensional transient heat-transfer model was proposed, taking the variation in the rate of power input, the phase transition of PE, and the thermal contact conductance between heating wire and PE into consideration. Then, experiments were designed to verify the power input and the temperature. The measured values of the power input were shown to be in good agreement with the analytical results. Based on ultrasonic test (UT), a new “Eigen-line” method was presented, which overcomes the difficulties found in the thermocouples’ temperature measurements. The results demonstrate good agreements between prediction and experiment. Finally, based on the presented model, a detailed parametric study was carried out to investigate the influences of the variation in the power input, the physical properties of PE, and the thermal contact conductance between heating wire and surrounding PE.

The Effect of Heat Treatment on Mechanical Properties of Car Interior Fabric Used for Injection Molding

2012 ◽  
Vol 532-533 ◽  
pp. 234-237
Author(s):  
Wei Lai Chen ◽  
Ding Hong Yi ◽  
Jian Fu Zhang
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
High Temperature ◽  
Injection Molding ◽  
High Temperatures ◽  
Material Properties ◽  
Injection Molding Process ◽  
Molding Process ◽  
Composite Fabrics

The purpose of this paper is to study the effect of high temperature in injection molding process on mechanical properties of the warp-knitted and nonwoven composite fabrics (WNC)used in car interior. Tensile, tearing and peeling properties of WNC fabrics were tested after heat treatment under120, 140,160,180°C respectively. It was found that, after 140°C heat treatment, the breaking and tearing value of these WNC fabrics are lower than others. The results of this study show that this phenomenon is due to the material properties of fabrics. These high temperatures have no much effect on peeling properties of these WNC fabrics. It is concluded that in order to preserve the mechanical properties of these WNC fabrics, the temperature near 140°C should be avoided possibly during injection molding process.

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