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Search results for: EXHAUST GAS TEMPERATURE
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Analysis of Airport Runoff Waters
PublicationA particularly important facet of airport operation is the impact of the pollution caused byrunoff waters. Runoff waters at an airport may contain relatively high concentrations of differentcontaminants resulting from the various aspects of its operation: de/anti-icing operations,washing and cleaning operations, spills of fuel and lubricants, exhaust fumes, and weed removal.The pollution caused by airport operations affects soil,...
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Carbon dioxide potential reduction using Start-Stop system in a car
PublicationOperating fuel consumption increases significantly when the vehicle stops frequently while driving or when the engine is idling during braking. In such cases, the internal combustion engine consumes the fuel but the mechanical energy is not used by the drive system. The amount of fuel that is consumed in this time by the engine can potentially be saved if the car is equipped with a Stop-Start system. Start-Stop system automatically...
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Investigation of Narrow Transverse and Longitudinal Electrostatic Precipitators
PublicationDiesel engines emit fine particles, which are harmful to human and animal health. There are several methods for decrease particulate emission from a diesel engines, but up to now, these methods are not enough effective or very expensive. An electrostatic precipitation was proposed as an alternative method for control of a diesel particulate emission. Therefore, narrow electrostatic precipitators (ESPs) have become a subject of...
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Resistive gas sensors – Perspectives on selectivity and sensitivity improvement
PublicationResistive gas sensors are very popular and relatively inexpensive; they can operate at elevated or room temperature for years on end. The main disadvantage of resistive gas sensors is their limited selectivity and sensitivity, but various methods have been applied to improve their behavior. The composition of the porous gas sensing layer, or changes in the sensor’s operating temperature, can enhance the gas detection ability. Furthermore, emerging...
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Analysis of Signalized Intersections in the Context of Pedestrian Traffic
PublicationGdynia is a city in the Pomeranian Voivod e ship of Poland with a population of about 250,000. It faces a growing motorization rate th at needs to be addressed. Car ownership in Gdynia now exceed s 500 vehicles per 1000 residents. Travel by public transport is decreasing and the rate of walking and cycling remains low. It is necessary to reverse these negative trends by implementing solu tions based...
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APPLICABILITY OF INLET AIR FOGGING TO MARINE GAS TURBINE
PublicationThe dependency of marine gas turbine on the ambient temperature leads to a decrease of the gas turbine power output in arid areas. Very often gas turbine power output demand is high and the power margins originally designed into the driver , has been exhausted. In such circumstances the inlet air fogging is an effective compensation of gas turbine power. In this paper an analysis of inlet air fogging applicability to marine gas...
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A calibration model for gas sensor array in varying environmental conditions
PublicationAbstract: Gas-analyzing systems based on gas sensors, commonly referred to as electronic noses, are the systems which enable the recognition of volatile compounds in their working environment and provide the on-line results of analysis. The most commonly used type of sensors in such systems is semiconductor gas sensors. They are considered to be the most reliable in the long-term applications (more than 1 year), however,...
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A calibration model for gas sensor array in varying environmental conditions
PublicationAbstract: Gas-analyzing systems based on gas sensors, commonly referred to as electronic noses, are the systems which enable the recognition of volatile compounds in their working environment and provide the on-line results of analysis. The most commonly used type of sensors in such systems is semiconductor gas sensors. They are considered to be the most reliable in the long-term applications (more than 1 year), however,...
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A review on application of artificial neural network (ANN) for performance and emission characteristics of diesel engine fueled with biodiesel-based fuels
PublicationBiodiesel has been emerging as a potential and promising biofuel for the strategy of reducing toxic emissions and improving engine performance. Computational methods aiming to offer numerical solutions were inevitable as a study methodology which was sometimes considered the only practical method. Artificial neural networks (ANN) were data-processing systems, which were used to tackle many issues in engineering and science, especially...
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Utilization of the zero unitarization method for the building of a ranking for diagnostic marine engine parameters
PublicationChanging some of the parameters of the engine structure affects the emission of harmful components in the exhaust gases This primarily concerns damage in the cargo exchange system as well as in the fuel system and engine boost system. Changes in emissions of harmful compounds are often ambiguous, depending largely on the parameters that shape the combustion process. An additional problem is that often simple but undesired interactions...
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GRAPHENE IN GAS CHEMIRESISTORS
PublicationGraphene has a range of unique physical properties which could be exploited in gas sensing. Every atom of graphene may be considered as a surface atom, able to interact even with single molecule of the target gas or vapour species resulting in the ultrasensitive sensor response. In this paper the potential of graphene as a nanomaterial for fabricating chemiresistors was described. Recent development in graphene sensors was considered...
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Gas Detection Using Resistive Gas Sensors And Radial Basis Function Neural Networks
PublicationWe present a use of Radial Basis Function (RBF) neural networks and Fluctuation Enhanced Sensing (FES) method in gas detection system utilizing a prototype resistive WO3 gas sensing layer with gold nanoparticles. We investigated accuracy of gas detection for three different preprocessing methods: no preprocessing, Principal Component Analysis (PCA) and wavelet transformation. Low frequency noise voltage observed in resistive gas...
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Noise related to gas bottles explosions
PublicationModern industrialized world is in a never ending danger of accidents and catastrophes of technical nature. Some of them may involve fires and explosions of gas storage bottles or containers. Technical University of Gdansk, Poland performed numerous tests where bottles containing acetylene, oxygen, hydrogen, CO2, LPG, LNG or CNG were blown due to excessive temperature caused by fire. Although those experiments were not focused on...
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Investigation of the Combustion Processes in the Gas Turbine Module of an FPSO Operating on Associated Gas Conversion Products
PublicationIn this paper, we consider the issue of thermo-chemical heat recovery of waste heat from gas turbine engines for the steam conversion of associated gas for offshore vessels. Current trends in the development of offshore infrastructure are identified, and the composition of power plants for mobile offshore drilling units and FPSO vessels is analyzed. We present the results of a comparison of power-to-volume ratio, power-to-weight...
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New approaches for improving selectivity and sensitivity of resistive gas sensors: A review
PublicationResistive gas sensors are very popular and reliable but suffer from low selectivity and sensitivity. Various methods have been suggested to improve both features without increasing the number of sensors in gas detection systems. Fluctuation enhanced gas sensing was proposed to improve gas detection efficiency by analyzing low-frequency resistance fluctuations, and noise parameters can be more informative than the single DC resistance...
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Limited selectivity of amperometric gas sensors operating in multicomponent gas mixtures and methods of selectivity improvement
PublicationIn recent years, smog and poor air quality have became a growing environmental problem. There is a need to continuously monitor the quality of the air. The lack of selectivity is one of the most important problems limiting the use of gas sensors for this purpose. In this study, the selectivity of six amperometric gas sensors is investigated. First, the sensors were calibrated in order to find a correlation between the concentration...
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Gas boiler as a heat source for the domestic micro-CHP
PublicationIn the presented analysis a commercially available domestic gas boiler as a heat source for domestic ORC is considered. The applicability of the gas boiler (De Dietrich with thermal power 25 kW) coupled with the laboratory prototype micro ORC setup has experimentally studied. The main aim of the study is to determine the working fluid temperature, attainable heat rates and efficiencies of the whole system. Preliminary investigations...
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Gas boiler as a heat source for the domestic micro-CHP
PublicationThis analysis considers a commercially available domestic gas boiler as a heat source for a domestic organic Rankine cycle system. An experimental study was made into the applicability of the gas boiler (De Dietrich with thermal power 25 kW) coupled with the laboratory prototype micro ORC setup. The main aim of the study is to determine the working fluid temperature, attainable heat rates and effciencies of the whole system. Preliminary...
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Problems of modelling toxic compounds emitted by a marine internal combustion engine for the evaluation of its structure parameters
PublicationThe paper presents the possibility of using an analytical study of the engine exhaust ignition to evaluate the technical condition of the selected components. Software tools available for the analysis of experimental data commonly use multiple regression model that allows the study of the effects and iterations between model input quantities and one output variable. The use of multi-equation models gives a lot of freedom in the...
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New approaches for improving selectivity and sensitivity of resistive gas sensors: a review
PublicationPurpose – This paper aims to present the methods of improving selectivity and sensitivity of resistance gas sensors. Design/methodology/approach – This paper compares various methods of improving gas sensing by temperature modulation, UV irradiation or fluctuation-enhanced sensing. The authors analyze low-frequency resistance fluctuations in commercial Taguchi gas sensors and the recently developed tungsten trioxide (WO3) gas-sensing...
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Analysis of the influence of external conditions on temperature readings in thermograms and adaptive adjustment of the measured temperature value
PublicationMeasuring human temperature is a crucial step in preventing the spread of diseases such as COVID-19. For the proper operation of an automatic body temperature measurement system throughout the year, it is necessary to consider outdoor conditions. In this paper, the effect of atmospheric factors on facial temperature readings using infrared thermography is investigated. A thorough analysis of the variation of facial temperature...
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Thermal failure of a second rotor stage in heavy duty gas turbine
PublicationThe impulse mode of operation and the supply of various types of fuels causes frequent failures even in the heavy duty gas turbines. The paper presents the ravages of second rotor stage failure in a gas turbine. The excessive thermal elongation rise caused by fuel change was indicated as the main cause. We applied nonlinear numerical analysis, preceded by thermodynamic calculations of the turbine and visual inspection of the effects...
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Polypyrrole based gas sensor for ammonia detection
PublicationThe nature of polypyrrole response to toxic gases does not allow using the sensor in a conventional way. The main aim of this study is to acquire the information about the concentration using different approaches: a linear approximation, a non-linear approximation and a tangent method. In this paper a two-steps procedure for sensor response measurements has been utilized. Polypyrrole films were electrochemically synthesized on...
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Extraction and evaluation of gas-flow-dependent features from dynamic measurements of gas sensors array
PublicationGas analyzers based on gas sensors are the devices which enable recognition of various kinds of volatile compounds. They have continuously been developed and investigated for over three decades, however there are still limitations which slow down the implementation of those devices in many applications. For example, the main drawbacks are the lack of selectivity, sensitivity...
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INVESTIGATION OF THE CHARACTERISTICS OF A LOWEMISSION GAS TURBINE COMBUSTION CHAMBER OPERATING ON A MIXTURE OF NATURAL GAS AND HYDROGEN
PublicationT his article is devoted to the investigation of the characteristics of a low-emission gas turbine combustion chamber, which can be used in Floating Production, Storage and Offloading (FPSO) vessels and operates on a mixture of natural gas and hydrogen. A new approach is proposed for modelling the processes of burning out a mixture of natural gas with hydrogen under preliminary mixing conditions in gaseous fuel with an oxidizer...
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Negative carbon dioxide gas power plant integrated with gasification of sewage sludge
PublicationOne of the primary objectives of the negative carbon dioxide gas power plant (nCO2PP) is to develop an innovative technology confirming the possibility of the use of sewage sludge to produce electricity while having a positive impact on the environment. In this paper, a mathematical model is presented to estimate thermodynamic parameters of the system in relation to the gasification process and changes in such parameters in the...
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Gas mixtures recognition using an array of amperometric gas sensors with drifting or faulty sensors
PublicationIn this study, the possibility of using selected methods for diagnostics of performance of matrix composed with six amperometric electrochemical gas sensors is investigated. Measurements of sensor responses in selected concentrations of single toxic gases or gas mixtures were performed and were repeated over time to show sensor drift. Additionally, the studies on the sensors’ drift were performed. The drift has been recognized...
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Hydrogen sulphide electrocatalytic gas sensor
PublicationIn this article measurement results of the electrocatalytic gas sensor in different concentrations of hydrogen sulphide are presented. Working principle of such sensor is based on electric current acquisition, while voltage ramp is applied to the sensor. During voltage sweep oxidation and reduction reactions occurs on the sensor electrodes. Obtained current-voltage plot has unique shape connected...
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Decomposition of Acoustic and Entropy Modes in a Non-Isothermal Gas Affected by a Mass Force
PublicationDiagnostics and decomposition of atmospheric disturbances in a planar flow are considered in this work. The study examines a situation in which the stationary equilibrium temperature of a gas may depend on the vertical coordinate due to external forces. The relations connecting perturbations are analytically established. These perturbations specify acoustic and entropy modes in an arbitrary stratified gas affected by a constant...
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Devices for the production of reference gas mixtures
PublicationFor many years there has been growing demand for gaseous reference materials, which is connected with development in many fields of science and technology. As a result, new methodological and instrumental solutions appear that can be used for this purpose. Appropriate quality assurance/quality control (QA/QC) must be used to make sure that measurement data are a reliable source of information. Reference materials are a significant...
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Transportable, Portable and Micro Gas Chromatographs
PublicationSignificant benefits can be obtained by miniaturization of conventional benchtop gas chromatographs. The attractive features arising from miniaturization include low-power requirements, low heat capacity of separation columns, low consumption of mobile phase, enhanced performance, higher portability, and easily coupling to detectors and secondary chromatographic systems. In separation sciences, including gas phase separations,...
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Efficiency of linear and non-linear classifiers for gas identification from electrocatalytic gas sensor
PublicationElectrocatalytic gas sensors belong to the family of electrochemical solid state sensors. Their responses are acquired in the form of I-V plots as a result of application of cyclic voltammetry technique. In order to obtain information about the type of measured gas the multivariate data analysis and pattern classification techniques can be employed. However, there is a lack of information in literature about application of such...
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Fluctuation enhanced gas sensing with WO3-based nanoparticle gas sensors modulated by UV light at selected wavelengths
PublicationThe sensitivity and selectivity of WO3-based gas sensors can be enhanced by UV-irradiation-induced modulation, especially if different wavelengths are employed. We used fluctuation-enhanced gas sensing, based on measurements of resistance fluctuations in the gas sensor, to study the effects of such modulation on the noise intensity for ambient atmospheres of synthetic air without and with additions of small amounts of ethanol,...
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INFLUENCE OF TEMPERATURE ON THE TYRE ROLLING RESISTANCE
PublicationTemperature is a very important factor controlling rolling resistance of road vehicle tyres. There are at least three different temperatures that may be considered as important factors controlling thermal conditions of the rolling tyre. The most common measure of the thermal conditions during tyre rolling is ambient air temperature. The other two are: pavement temperature and “tyre” temperature. Tyre temperature is the most difficult...
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Interaction of Acoustic and Thermal Modes in the Gas with Nonequilibrium Chemical Reactions: Possibilities of Acoustic Cooling
PublicationNonlinear generation of thermal mode during propagation of dominative sound in a chemically reacting gas is considered. The dynamic equation of excess temperature associated with the thermal mode is derived. It is instantaneous and includes quadratic nonlinear acoustic source reflecting the nonlinear character of interaction between acoustic and non-acoustic types of gas motion. Both periodic and aperiodic sound may be considered...
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Shooting Gas Cylinders to Prevent Their Explosion in Fire
PublicationGas cylinders in general, and particularly cylinders containing acetylene, constitute a great potential danger to fire and rescue services involved in salvage operations. Experiments show that gas cylinders with acetylene, oxygen, hydrogen, CNG, LPG or CO2 may blow after short exposition to heat with very destructive effect as fragments of blown cylinder may fly even several hundred meters. In the case of acetylene the explosion...
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Study of the influence of thermal factors on the welding process of polyethylene gas pipelines,
PublicationA one-dimensional calculation scheme is proposed with the help of which it is possible to determine and set the technological parameters with the accuracy to be realized in production conditions: the temperature of the heating element and the heating time, which allows maximum mechanization of the technological operations of polyethylene gas pipelines welding. The numerical value of the coefficient of temperature for polyethylene...
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Method of selecting the LS-SVM algorithm parameters in gas detection process
PublicationIn this paper we showed the method of resistive gas sensors data processing. The UV irradiation and temperature modulation was applied to improve gas sensors’ selectivity and sensitivity. Noise voltage across the sensor’s terminals (proportional to its resistance fluctuations) was recorded to estimate power spectral density. This function was an input data vector for LS-SVM (least squares – support vector machine) algorithm, which...
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Quantum dots in gas sensing a review
PublicationAir pollution becomes an increasing problem in the recent years. There is a need to develop more sensitive gas sensors. Much effort has been performed to develop different types of gas sensors, such as electrochemical sensors or polymer sensors. One of the most promising approaches to improve sensors performance is the application of the nanostructures as sensing materials. State of the art of quantum...
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Evaluation of the Commercial Electrochemical Gas Sensors for the Monitoring of CO in Ambient Air
PublicationAir pollution is a growing concern of civilized world, which has a significant impact on human health and the environment. Recent studies highlight that the exposure to polluted air can increase the incidence of diseases and deteriorate the quality of life. Hence, it is necessary to develop tools for real-time air quality monitoring. For air pollution monitoring a wide range of stationary gas and particulate analysers can be used....
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Real-time working gas recognition system based on the array of semiconductor gas sensors and portable computer Raspberry PI
PublicationThe gas-analyzing systems based on the array of partially selective gas sensors and pattern-recognition techniques are potentially fast and low-cost alternative for other devices, like gas analysers. They give the possibility of recognition the type and the concentration of measured volatile compounds in their working environment. In this work we present the implementation of gas recognition system, in which the signals from an...
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Numerical analysis of high temperature minichannels heat exchanger performance
PublicationNowadays, the most difficult technological challenge in energy sector is connected with the gas micro-CHP units, dedicated to the distributed power generation. They are expected to be of high efficiency and at the same time of compact in size. Regarding the first reason, significant increase in microturbine efficiency can only be achieved by increase in the engine operating temperature. Therefore, one of the critical elements in...
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Embedded gas sensing setup for air samples analysis
PublicationThis paper describes a measurement setup (eNose) designed to analyze air samples containing various volatile organic compounds (VOCs). The setup utilizes a set of resistive gas sensors of divergent gas selectivity and sensitivity. Some of the applied sensors are commercially available and were proposed recently to reduce their consumed energy. The sensors detect various VOCs at sensitivities determined by metal oxide sensors’ technology...
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Domestic ORC micro-CHP combined with a commercial gas boiler
PublicationThe chapter presents the results of experimental studies conducted during the launch of the first in Poland demonstration prototype of the micro ORC coupled to a domestic gas boiler. The accomplished studies indicated the possibility for the ORC module to work with such boiler (autonomous source of heat) with a prototype single-stage axial micro turbine as the expansion machine. Confirmation of that fact has been delineated in...
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Pulsed UV-irradiated Graphene Sensors for Ethanol Detection at Room Temperature
PublicationA graphene-based gas sensor fabricated in a FET (GFET) configuration and its sensitivity towards ethanol and methane is reported. Detection of ethanol at the level of 100 ppm was observed under pulsed UV irradiation and after cleaning by UV light in the N2 ambient. Reduction of the frequency of UV irradiation pulses resulted in increased changes in sensor resistance in the presence of ethanol. Improved sensing behavior was ascribed...
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AUTOMATED SYSTEM FOR FLUCTUATION ENHANCED GAS SENSING
PublicationResistance gas sensors exhibit random phenomena (resistance noise) which can be utilized to improve gas sensitivity and selectivity. That new emerging technique has to be investigated to recognize optimal parameters for gas detection. It means that a measurement system has to have ability of numerous parameters adjustment (e.g., sampling frequency, heater voltage, polarization current, voltage noise amplification). That fact induced...
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ENERGY EFFICIENT AND ENVIRONMENTALLY FRIENDLY HYBRID CONVERSION OF INLAND PASSENGER VESSEL
PublicationThe development and growing availability of modern technologies, along with more and more severe environment protection standards which frequently take a form of legal regulations, are the reason why attempts are made to find a quiet and economical propulsion system not only for newly built watercraft units, but also for modernised ones. Correct selection of the propulsion and supply system for a given vessel affects significantly...
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Perforating systems in shale gas recovery
PublicationHydraulic fracturing is common method of shale gas recovery. Due to environmental, economical and technological problems many alternative technologies have been developed. One of the most promising group of technologies is based on perforating systems. This paper describes theoretical and practical aspects of best known technologies used to create perforations. New perforating/fracturing technologies which can replace hydraulic fracturing...
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Determination Of Gas Mixture Components Using Fluctuation Enhanced Sensing And The LS-SVM Regression Algorithm
PublicationThis paper analyses the effectiveness of determining gas concentrations by using a prototype WO3 resistive gas sensor together with fluctuation enhanced sensing. We have earlier demonstrated that this method can determine the composition of a gas mixture by using only a single sensor. In the present study, we apply Least-Squares Support-Vector-Machine-based (LS-SVM-based) nonlinear regression to determine the gas concentration...
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Comparative analysis of thermodynamic cycles of selected nuclear ship power plants with high-temperature helium-cooled nuclear reactor
PublicationThis paper presents a comparative analysis of thermodynamic cycles of two ship power plant systems with a high-temperature helium- cooled nuclear reactor. The first of them is a gas system with recuperator , in which classical gas chamber is substituted for a HTGR reactor (High Temperature Gas-cooled Reactor) . The second of the considered cycles is a combined gas-steam system where working medium flux from gas turbine outlet...