scholarly journals Characteristic Curves of Iridium-Rhodium Sensing Elements in High-Temperature Transducer Applications

2021 ◽  
Vol 7 (1) ◽  
pp. 62-67
Author(s):  
Vasyl Fedynets ◽  
◽  
Yaroslav Yusyk ◽  
Ihor Vasylkivskyi

In order to increase the capacity and efficiency factor of gas turbines and internal combustion engines while preserving their high reliability, the gas temperature and its distribution need to be measured in combustion chambers. Values of these temperatures can exceed 1800°С in an oxidizing atmosphere. Therefore, designing temperature transducers for measurements in such severe environments, special attention should be paid to the selection of thermometric materials. The requirements of the necessary accuracy and temperature range over 1800°С in an oxidizing atmosphere are fulfilled only by the temperature transducer based on iridium-rhodium alloys. The characteristic curve of such sensing elements is individual and each temperature transducer is to be calibrated. The paper discusses a technique of determining the individual characteristic curve of iridium-rhodium sensing elements of high-temperature transducers. The preparation steps to be taken prior to the calibration and the main stages of determining the characteristic curve are described. The general view of the experimental set for calibrating the sensing elements is presented. Based on the calibration results, the form of approximating polynomial of the individual characteristic curve is proposed.

2019 ◽  
Vol 2019 (HiTen) ◽  
pp. 000001-000006
Author(s):  
John R. Fraley ◽  
Alan Mantooth ◽  
Sajib Roy ◽  
Robert Murphree ◽  
Affan Abassi ◽  
...  

ABSTRACT As advanced natural gas power generation systems evolve, the thrust for increased efficiencies and reduced emissions results in increasingly harsh conditions inside the turbine environment. These high temperatures, pressures, and corrosive atmospheres result in accelerated rates of degradation, leading to failure of turbine materials and components. The University of Arkansas (UA) and Siemens, in collaboration with the DoE's National Energy Technology Laboratory (NETL), are developing a reliable and long-term monitoring capability in the turbine hot gas path in the form of novel ceramic-based thermocouples and integrated wide band gap instrumentation electronics that will contribute to the overall reliability of gas turbines. When equipped with better monitoring and controls, power plants can operate with increased fuel-burning efficiency, improved process dynamics and gas concentrations, and increased overall longevity of the power plant components. This will result in increased turbine availability and a reduction in outages and maintenance costs. One of the key aspects to driving forward turbine monitoring capability is the development of high temperature capable integrated circuit (IC) electronics. Previous papers have described 500 °C + electronics that were developed primarily from a combination of discrete single transistors combined with supporting high temperature passive components. While these circuits have been tested successfully in high temperature spin test environments, the move to an IC approach will greatly increase the performance and reliability of turbine monitoring systems. This program is developing such capability through the implementation of silicon carbide (SiC) based ICs, and this paper details the initial approach and early testing of the developed devices. This research represents an important step towards the realization of a field deployable high reliability turbine condition monitoring system.


1963 ◽  
Vol 85 (2) ◽  
pp. 99-106 ◽  
Author(s):  
R. W. Kelly ◽  
G. M. Wood ◽  
H. V. Marman

High performance, mobile, nuclear power plants utilizing liquid metals require high temperature pumps to circulate these heat transport fluids. These pumps must have moderately high efficiency, small size, low weight, and high reliability. In order to satisfy these requirements, centrifugal pumps directly coupled to gas turbines are utilized. As part of the aircraft nuclear power plant development program, the 3000 gpm stainless steel turbopump described in this paper was designed and tested in NaK at temperatures up to 1300 F.


Author(s):  
QI CHEN ◽  
◽  
JINTAO SUN ◽  
JIANYU LIU ◽  
BAOMING ZHAO ◽  
...  

Plasma-assisted ignition and combustion, widely applied in gas turbines, scramjets, and internal combustion engines, has been considered as a promising technique in shortening ignition delay time, improving combustion energy efficiency, and reducing emission. Nonequilibrium plasma can excite the gas molecules to higher energy states, directly dissociate or ionize the molecules and, thereby, has the potential to produce reactive species at residence time and location in a combustible mixture and then to efficiently accelerate the overall pyrolysis, oxidation, and ignition. Previous studies have demonstrated the effectiveness of plasma-assisted combustion by using direct current, alternating currant, microwave, radio frequency, and pulsed nanosecond discharge (NSD). Due to the complicated interaction between plasma and combustion in different types of plasma, detailed plasma-combustion chemistry is still not well understood.


Alloy Digest ◽  
1963 ◽  
Vol 12 (8) ◽  

Abstract Carpenter SIL No. 1 is a hardenable silicon-chromium alloy steel that is used in applications where the operating temperatures are below 1000 F. It is widely used for intake valves and for exhaust valve stems in internal combustion engines. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, and machining. Filing Code: SA-152. Producer or source: Carpenter.


Alloy Digest ◽  
1963 ◽  
Vol 12 (1) ◽  

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.


2006 ◽  
Vol 527-529 ◽  
pp. 999-1002
Author(s):  
Junji Senzaki ◽  
Atsushi Shimozato ◽  
Kenji Fukuda

Low-temperature post-oxidation annealing (POA) process of high-reliability thermal oxides grown on 4H-SiC using new apparatus that generates atomic hydrogen radicals by high-temperature catalyzer has been investigated. Atomic hydrogen radicals were generated by thermal decomposition of H2 gas at the catalyzer surface heated at high temperature of 1800°C, and then exposed to the sample at 500°C in reactor pressure of 20 Pa. The mode and maximum values of field-to-breakdown are 11.0 and 11.2 MV/cm, respectively, for the atomic hydrogen radical exposed sample. In addition, the charge-to-breakdown at 63% cumulative failure of the thermal oxides for atomic hydrogen radical exposed sample was 0.51 C/cm2, which was higher than that annealed at 800°C in hydrogen atmosphere (0.39 C/cm2). Consequently, the atomic hydrogen radical exposure at 500°C has remarkably improved the reliability of thermal oxides on 4H-SiC wafer, and is the same effect with high-temperature hydrogen POA at 800°C.


2014 ◽  
Vol 907 ◽  
pp. 139-149 ◽  
Author(s):  
Eckart Uhlmann ◽  
Florian Heitmüller

In gas turbines and turbo jet engines, high performance materials such as nickel-based alloys are widely used for blades and vanes. In the case of repair, finishing of complex turbine blades made of high performance materials is carried out predominantly manually. The repair process is therefore quite time consuming. And the costs of presently available repair strategies, especially for integrated parts, are high, due to the individual process planning and great amount of manually performed work steps. Moreover, there are severe risks of partial damage during manually conducted repair. All that leads to the fact that economy of scale effects remain widely unused for repair tasks, although the piece number of components to be repaired is increasing significantly. In the future, a persistent automation of the repair process chain should be achieved by developing adaptive robot assisted finishing strategies. The goal of this research is to use the automation potential for repair tasks by developing a technology that enables industrial robots to re-contour turbine blades via force controlled belt grinding.


Processes ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 996
Author(s):  
Venera Giurcan ◽  
Codina Movileanu ◽  
Adina Magdalena Musuc ◽  
Maria Mitu

Currently, the use of fossil fuels is very high and existing nature reserves are rapidly depleted. Therefore, researchers are turning their attention to find renewable fuels that have a low impact on the environment, to replace these fossil fuels. Biogas is a low-cost alternative, sustainable, renewable fuel existing worldwide. It can be produced by decomposition of vegetation or waste products of human and animal biological activity. This process is performed by microorganisms (such as methanogens and sulfate-reducing bacteria) by anaerobic digestion. Biogas can serve as a basis for heat and electricity production used for domestic heating and cooking. It can be also used to feed internal combustion engines, gas turbines, fuel cells, or cogeneration systems. In this paper, a comprehensive literature study regarding the laminar burning velocity of biogas-containing mixtures is presented. This study aims to characterize the use of biogas as IC (internal combustion) engine fuel, and to develop efficient safety recommendations and to predict and reduce the risk of fires and accidental explosions caused by biogas.


2021 ◽  
Vol 13 (7) ◽  
pp. 4006
Author(s):  
Lisa Branchini ◽  
Maria Chiara Bignozzi ◽  
Benedetta Ferrari ◽  
Barbara Mazzanti ◽  
Saverio Ottaviano ◽  
...  

Ceramic tile production is an industrial process where energy efficiency management is crucial, given the high amount of energy (electrical and thermal) required by the production cycle. This study presents the preliminary results of a research project aimed at defining the benefits of using combined heat and power (CHP) systems in the ceramic sector. Data collected from ten CHP installations allowed us to outline the average characteristics of prime movers, and to quantify the contribution of CHP thermal energy supporting the dryer process. The electric size of the installed CHP units resulted in being between 3.4 MW and 4.9 MW, with an average value of 4 MW. Data revealed that when the goal is to maximize the generation of electricity for self-consumption, internal combustion engines are the preferred choice due to higher conversion efficiency. In contrast, gas turbines allowed us to minimize the consumption of natural gas input to the spray dryer. Indeed, the fraction of the dryer thermal demand (between 600–950 kcal/kgH2O), covered by CHP discharged heat, is strictly dependent on the type of prime mover installed: lower values, in the range of 30–45%, are characteristic of combustion engines, whereas the use of gas turbines can contribute up to 77% of the process’s total consumption.


Author(s):  
Michele Scervini ◽  
Catherine Rae

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.


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