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Advanced Sensors and Instrumentation Systems for Combustion Processes (Ref. No. 2000/080) IEE Seminar

Date 2000

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Displaying Results 1 - 13 of 13
  • The possibilities for high temperature electronics in combustion monitoring

    Page(s): 9/1 - 9/3
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (352 KB)  

    High temperature electronics will increasingly penetrate the market for combustion monitoring and control; particularly where distributed systems and/or improved performance are required. HTE will enable sensors with increased functionality to be placed nearer to the actual point of combustion, which in turn will allow improved combustion efficiency. HITEN is a network of excellence in high temperature electronics whose mission is to encourage and support the development and application of high temperature electronics, worldwide View full abstract»

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  • Advanced monitoring and characterisation of combustion flames

    Page(s): 3/1 - 3/4
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (348 KB)  

    This paper describes the advanced monitoring and characterisation of a gaseous flame in a 10 MWth utility boiler using a recently developed instrumentation system. The physical properties of the flame are characterised in terms of a set of geometrical and luminous parameters, which are derived from the digital images of the flame. Results obtained have demonstrated that the system is capable of characterising the flame both qualitatively and quantitatively. The results have also revealed that the geometrical and luminous parameters have close relationships with the air/fuel flow rates and emissions of the boiler View full abstract»

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  • Measurement of emissions from offshore combustion-user's requirements

    Page(s): 7/1 - 7/3
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (276 KB)  

    UK offshore legislation has just been introduced that requires monitoring of pollutants from gas turbines. This has meant a marked change in culture and technology as traditionally there has been a `fuel is free' mentality. Also emissions have rarely been measured. The remote location of offshore platforms means that unique solutions are required, especially regarding any changes in the plant that are necessary to install instrumentation. Accuracy and reliability of the instrumentation is crucial. No solutions are proposed in this paper. The objective is to review the background to the user's requirements in light of the change in culture and the new legislation. A challenge is set to the industry to produce cost effective and accurate monitoring methods View full abstract»

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  • Robust instrumentation for high accuracy temperature measurement

    Page(s): 10/1 - 10/4
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (304 KB)  

    A robust, highly stable, resistance thermometry instrument has been developed for use in the on-board calibration system of a space-borne infrared radiometer. At the beginning of its life, the reproducibility has been demonstrated to be better than 2.5 mK. The instrument uses an AC bridge based on novel miniature inductive components and nonelectromechanical inter-stage switching which results in a unit weighing ~1.5 kg. Several units of similar design have been built to withstand high levels of mechanical vibration and shock, extended temperature ranges, operation in vacuum and exposure to ionising radiation View full abstract»

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  • Analysis methodology of diesel spray and flame by means of in-cylinder endoscopic imaging

    Page(s): 13/1 - 13/4
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (508 KB)  

    In-cylinder endoscopic imaging has been presented as an optical diagnostic tool for diesel spray injection and combustion studies. The basic methodology for the tests and subsequent image processing has been discussed, together with some limitations to be taken into account. The results show that endoscopy can provide additional information about some important processes related to the development of combustion, for which conventional non-optical procedures can give no account View full abstract»

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  • A combustion scientist's view of thermocouple temperature measurement

    Page(s): 11/1 - 11/4
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (268 KB)  

    This paper is concerned with applications of thermoelectric thermometry to certain combustion applications. The author is of the view that in such applications all due care in setting up and operating thermocouple circuits should be taken. However, in combustion applications perhaps more than in most others, measurement errors having their origin in such things as calibration uncertainties and unwanted e.m.f.'s are minute in comparison with potential errors from heat transfer effects View full abstract»

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  • Acoustic temperature measurement of combustion chambers

    Page(s): 5/1 - 5/4
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (332 KB)  

    The phenomenon of the noise given off by burners and flames has been the subject of much study. However all of these studies have concentrated on laboratory scale experiments and thus while noting complex relationships between temperature, noise and pressure signals these results have not been replicated on an operational system. This paper will examine an attempt to look at the noise and pressure variations generated by a full scale operational plant and correlate them to the temperature of the chamber View full abstract»

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  • All-optoelectronic sensors for combustion-related processes

    Page(s): 8/1 - 8/4
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (448 KB)  

    Control of combustion processes can be enabled by monitoring the spatial distribution of chemical species, imaged by an appropriate tomographic technique. The overall performance of a system for optical tomographic imaging is determined by the performance of the individual sensors. Two particular sensor designs, based on optical beam attenuation have been investigated for in-situ and real-time monitoring of hydrocarbon concentration in the cylinder of an internal combustion engine, and for monitoring of NO2 concentration in the exhaust plume of a turbine engine View full abstract»

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  • Fuel characterisation for pulverised coal combustion

    Page(s): 2/1 - 213
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (724 KB)  

    Two inherent challenges in coal characterisation for pulverised fuel (PF) combustion which this paper addresses are: (a) the very large scale and severe conditions at which PF combustion takes place, (b) the heterogeneous and diverse properties that coal, as a natural material, displays. Since it is not possible to reproduce full scale PF combustion in the laboratory it is difficult to apply sufficiently-high heating rates and temperatures to reproduce actual PF combustion conditions for coal combustion processes. Results from a novel captive-sample reactor, which can apply well-controlled heating rates of 10,000 K/s and above to peak temperatures up to 2000"C, will be used to illustrate the importance of applying realistically-severe conditions when characterising coals for NOx performance and inherent char reactivity. It will be shown how properly-obtained coal characterisation data can be related directly to full-scale utility plant performance View full abstract»

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  • PF flow meter demonstration trials on a 500 MWe boiler

    Page(s): 1/1 - 1/6
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (512 KB)  

    Since the installation of low NOx burners, the optimisation and control of PF distribution and PF size distribution have assumed greater significance. Balanced PF distribution and satisfactory fineness are two of the fundamental criteria for effective low NOx burner operation in terms of both NO, and combustion efficiency (carbon in ash). Maldistribution of fuel between burners caused by fuel roping leads to uncontrolled differences in the fuel to air ratio between burners. This results in localised rich and lean regions in the furnace leading to unacceptably high levels of unburned carbon. This leads to difficulty in meeting stringent emission levels, boiler efficiency loss and potential loss of ash sales due to increased carbon content Presently extractive sampling techniques are used for assessing fuel distribution; however, such approaches can only provide data as a spot reading over a limited period and fail to show the dynamic nature of fuel distribution. Accurate measurement of pulverised fuel/airflow has been a long-standing problem for utility operators. Recent years have seen developments from a number of manufacturers that could potentially provide operators with the information to fully optimise the coal combustion process View full abstract»

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  • Fundamental flame flicker monitoring for power plant boilers

    Page(s): 4/1 - 4/4
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (256 KB)  

    A system for optically monitoring flames in large power plant boilers that indicates not only if the flames are present but also provides an indication of combustion quality View full abstract»

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  • Neural network models of the combustion derivatives emanating from a chain grate stoker fired boiler plant

    Page(s): 6/1 - 6/4
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (400 KB)  

    This paper is concerned with the use of neural networks as a means to represent the formation of pollutant emissions, resulting from the combustion of coal with a 1 MWth chain grate stoker test facility located at CRE Group Ltd. (CRE), Stoke Orchard, Cheltenham. The resultant `black-box' models of the pollutant emissions, namely the nitrogen oxides and carbon monoxide emissions, were able to represent the dynamics of the process and delivered reasonably accurate estimates over a wide range of unseen data. This system identification approach is in many ways a simplistic approach to that of the more daunting route of mathematically modelling the physical processes. The neural network model, although lacking in model transparency and elegance, is able to produce estimates of the derivatives of combustion with acceptable accuracy considering its relative simple model design. This has been demonstrated not only with data sets that were obtained from the same series of experiments but also from data with a temporal separation of 8 months from the training data. The work presented here addresses some of the deficiencies in the modelling of lump coal combustion on grates reported in the literature and the method adopted in this paper could be used to develop a `software sensor' that when linked to a combustion control system could help to minimise pollutant emissions of chain or travelling grate stokers View full abstract»

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  • Imaging combustion using electrical capacitance tomography

    Page(s): 12/1 - 12/4
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (460 KB)  

    It is well known that flames are rich in charged particles, ions and free electrons and such electrical activity will modify the permittivity and conductivity of the reaction zone. Work at UMIST over the past decade has led to the development of sensitive circuitry to detect such electrical changes within an enclosed volume. A commercially available electrical capacitance tomography (ECT) system, based on a switched capacitor circuit, was used in the investigations reported in this paper. Although nominally a capacitance measuring circuit, e.g. monitoring changes in permittivity, the ECT system also responds to changes in conductivity. In flames, the latter is normally the dominant effect. The ECT system has been connected to six electrodes inside a sealed combustion chamber, and used to monitor laminar methane/air flame propagation. The results were encouraging but inferior in spatial and temporal resolution to those obtained using high-speed Schlieren photography. A new (open) combustion can has been built, which has 12 electrodes, thus giving better spatial resolution. The new model is aimed at jet engine combustion studies. Here two factors are of particular importance: 1. Is the flame centrally located? and 2. Is the flame stable? The sensitivity of the ECT system increases rapidly as the flame approaches the electrodes and can thus be expected to highlight the two factors noted above View full abstract»

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