Metrological Study of the Operation of a Thermocatalytic Converter Under the Conditions of Measuring the Combustion Heat of Natural Gas

2019 ◽  
Author(s):  
H. Shynkaruk ◽  
S. Chekhovskyy ◽  
N. Pindus
Keyword(s):  
Natural Gas ◽  
Combustion Heat ◽  
Metrological Study

scholarly journals Gas Turbines and Biodiesel: A Clarification of the Relative NOX Indices of FAME, Gasoil, and Natural Gas

2009 ◽  
Author(s):  
Pierre A. Glaude ◽  
Rene´ Fournet ◽  
Roda Bounaceur ◽  
Michel Moliere
Keyword(s):  
Natural Gas ◽  
Gas Turbines ◽  
Methyl Esters ◽  
Flame Temperature ◽  
Field Tests ◽  
Animal Origin ◽  
Combustion Heat ◽  
Independent Field ◽  
Key Factor ◽  
The Usa

There is currently a sustained interest in biofuels as they represent a potential alternative to petroleum derived fuels. Biofuels are likely to help decrease greenhouse gases emissions and the dependence on oil resources. Biodiesels are Fatty Acid Methyl Esters (FAMEs) that are mainly derived from vegetable oils; their compositions depend from the parent vegetables: rapeseed (“RME”), soybean (“SME”), sunflower, palm etc. A fraction of biodiesel has also an animal origin (“tallow”). A key factor for the use of biofuels in gas turbines is their Emissions Indices (NOx, CO, VOC, PM) in comparison with those of conventional “petroleum gasoils”. While biodiesels reduce carbon-containing pollutants, experimental data from diesel engines show a slight increase in NOx. The literature relating to gas turbines is very scarce. Two recent, independent field tests carried out in Europe (RME) and in the USA (SME) showed slightly lower NOx while a lab test on a microturbine showed the opposite effect. To clarify the NOx index of biodiesels in gas turbines, a study has been undertaken, taking gasoil and natural gas (NG) as reference fuels. In this study, a calculation of the flame temperature developed by the 3 classes of fuels has been performed and the effect of their respective compositions has been investigated. The five FAMEs studied were RME, SME and methyl esters of sunflower, palm and tallow; these are representative of most widespread vegetable and animal oil bases worldwide. The software THERGAS has been used to calculate the enthalpy and free energy properties of the fuels and GASEQ for the flame temperature (Tf), acknowledging the fact that “thermal NOx” represents the predominant form of NOx in gas turbines. To complete the approach to structural effects, we have modeled two NG compositions (rich and weak gas) and three types of gasoil using variable blends of eleven linear/branched/cyclic molecules. The results are consistent with the two recent field tests and show that the FAMEs lie close to petroleum gasoils and higher than NG in terms of NOx emission. The composition of the biodiesel and regular diesel fuel influences their combustion heat: methyl esters with double bonds see a slight increase of their Tf and their NOx index while that of gasoil is sensitive to the aromatic content.

scholarly journals Research of the Influence of Temperature Factor on Express Control of Natural Gas Combustion Heat

2020 ◽  
pp. 44-50
Author(s):  
O. E. Seredyuk ◽  
N. M. Malisevich
Keyword(s):  
Natural Gas ◽  
Temperature Measurement ◽  
Flow Rate ◽  
Gas Flow ◽  
Flame Temperature ◽  
Operating Conditions ◽  
Gas Flow Rate ◽  
Combustion Heat ◽  
Gas Combustion ◽  
Functional Scheme

The article is devoted to the study of the influence of the qualitative and quantitative composition of gas environments on the flame temperature of the combusted gas at different values of gas flow rate and changes volume ratio gas-air in its combustion. The functional scheme of the developed labo­ratory stand (Fig. 1), which provides temperature measurement during combustion of natural gas or propane-butane mixture, is considered. The design of the developed burner is described and the expe­rimental researches are carried out when measuring the flame temperature of the combusted gas during the operation of the laboratory stand. The opera­ting conditions of different thermocouples in measuring the temperature of the flared gas are investigated (Fig. 2). The temperature instability in the lower and upper flames was experimentally determined (Fig. 3) and its difference from the reference data [12, 13]. The measurement of the flame temperature with a uncased thermocouple and two thermocouples of different types with protective housings is reali­zed. Methodical error of temperature measurement by different thermocouples was estimated (Fig. 5). An algorithm for the implementation of measurement control in determining the heat of combustion of natural gas according to the patented method is outlined [11]. Experimental studies of temperature changes of combusted gas mixtures at different gas flow rates and different ratios with air, which is additionally supplied for gas combustion, were carried out (Figs. 4, 7). The computer simulation (Figs. 6, 8) of the change in the flame temperature was performed on the basis of the experimental data, which allowed to obtain approximate equations of the functional dependence of the flame temperature on the gas flow rate and the ratio of the additional air and gas consumption. The possibility of realization of the device of express control of the heating value of natural gas by measuring the combustion temperature of the investigated gases, which is based on the expe­rimentally confirmed increase in the flame temperature of the investigated gases with increasing their calorific value, is substantiated (Fig. 9). The necessity of further investigation of the optimization design characteristics of the burner and the operating conditions of combustion of the gases under rapid cont­rol of their combustion heat was established (Fig. 9).

Modeling of Combustion Noise in Turbulent, Premixed Flames

2006 ◽  
Author(s):  
Jim B. W. Kok ◽  
Bram de Jager
Keyword(s):  
Steady State ◽  
Natural Gas ◽  
Source Term ◽  
Pressure Fluctuations ◽  
Combustion Noise ◽  
Volume Integral ◽  
Combustion Heat ◽  
Thermoacoustic Instabilities ◽  
Gas Flame ◽  
Turbulent Premixed

In regular operation all gas turbine combustors have a significant noise level induced by the turbulent high power flame. This noise is characteristic for the operation as it is the result of the interaction between turbulence and combustion. Pressure fluctuations may also be generated by thermoacoustic instabilities induced by amplification by the flame of the acoustic field in the combustor. This paper focuses on prediction of the former process of the noise generation in a premixed natural gas combustor. In order to predict noise generated by turbulent combustion, a model is proposed to calculate the power spectrum of combustion noise in a turbulent premixed natural gas flame on the basis of a steady state RaNS CFD analysis. The instantaneous propagation of acoustic pressure fluctuations is described by the Lighthill wave equation, with the combustion heat release acting as a monopole source term. For a semi infinite tube the solution can be written as a volume integral over the acoustic domain using a Green’s function. The source term is written as a function of a reaction progress variable for combustion. Finite chemical kinetics is taken into account by using the TFC model, and turbulence is described by the k-ε model. Subsequently the volume integral for the noise field is evaluated for the turbulent situation on basis of the calculated steady state combustion solution and presumed shape probability density function weighting. The k- ε model provides the parameters for the presumed spectrum shape. Experiments have been performed in a 100 kW preheated premixed natural gas combustor. Comparison of predicted sound spectra with experimental results shows that the model is capable of prediction of the Sound Pressure Level. The modeled spectrum agrees well with the trends observed in the measured spectra.

scholarly journals Features of application of the methane-hydrogen fraction as fuel for thermal power plant boiler

2019 ◽  
Vol 21 (3) ◽  
pp. 109-116
Author(s):  
M. A. Taymarov ◽  
V. K. Ilyin ◽  
E. G. Chiklyaev ◽  
R. G. Sungatullin
Keyword(s):  
Heat Flux ◽  
Natural Gas ◽  
Burning Rate ◽  
Hydrogen Content ◽  
Power Plants ◽  
Thermal Power ◽  
Petroleum Products ◽  
Heat Of Combustion ◽  
Combustion Heat ◽  
Gaseous Hydrocarbon

The methane-hydrogen fraction is a gaseous hydrocarbon by-product during oil processing for obtaining petroleum products. Until recently, the methane-hydrogen fraction was used as furnace oil in internal technological processes at a refinery. Some of the low-calorie methane-hydrogen fraction was burned in flares. Driven by the prospect of the methane-hydrogen fraction use as a fuel alternative to natural gas for burning in thermal power plants boilers, it became necessary to study the methane-hydrogen fraction combustion processes in large volumes. The conversion of ON-1000/1 and ON-1000/2 furnaces from the combustion of the methane- hydrogen fraction with combustion heat of 25.45 MJ/m3 to the combustion of the composition with combustion heat of 18.8 MJ/m3 leads to a decrease in temperature in the flame core for 100 °C as an average. The intensity of flame radiation on the radiant tubes decreases. Therefore, the operation of furnaces during combustion of methane-hydrogen fraction with a low heat of combustion at the gas oil hydro-treating unit is carried out only with a fresh catalyst, which allows lower flame temperatures in the burner.The experiments to determine the concentration of nitrogen oxides NOx and the burning rate w of the methane-hydrogen fraction in the ON-1000/1 furnace and natural gas in the TGM-84A boiler, depending upon the heat of combustion Qnr were carried out. The obtained results showed that the increase in the hydrogen content Н2 from 10.05 % to 18.36% (by mass) results in an increase in the burning rate w by 45%. The burning rate of natural gas with methane CH4 content of 98.89% in the TGM-84A boiler is 0.84 m/s, i.e. it is 2.5 times lower than the burning rate of the methane- hydrogen fraction with H2 content of 10.05%. The distributions of heat flux from the flame qf over the burner height h in the TGM-84A boiler were obtained in case of natural gas burning and calculation of burning of the methane-hydrogen fraction with a hydrogen content of 10.05% and methane of 28.27%. The comparison of the obtained data shows that burning of methane- hydrogen fraction causes an increase in the incident heat flux qf at the outlet of the burner.

scholarly journals Ways of reproduction and transfer of the natural gas combustion heat and density units in Ukraine

2018 ◽  
Vol 0 (4) ◽  
pp. 14-24
Author(s):  
Ігор Степанович Петришин ◽  
Олександр Анатолійович Бас ◽  
Людмила Олександрівна Присяжнюк
Keyword(s):  
Natural Gas ◽  
Combustion Heat ◽  
Gas Combustion ◽  
Natural Gas Combustion

scholarly journals NATURAL GAS HEAT COMBUSTION DETERMINATION ON MEASURING SYSTEMS WITH DUPLICATE GAS UNITS

2020 ◽  
Author(s):  
Igor Petryshyn ◽  
◽  
Olexandr Bas ◽  
◽  
Keyword(s):  
Natural Gas ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Volume Flow Rate ◽  
Molar Fraction ◽  
Volume Flow ◽  
Combustion Heat ◽  
Measuring Systems ◽  
Gas Volume

The paper focuses on the need to determine the natural gas heat combustion in order to transition to gas metering in units of energy. The technical organization of gas transportation in the main and distribution pipelines on the territory of Ukraine is shown. A detailed analysis of regulatory and legal support, which regulates the definition and accounting of quantitative and qualitative characteristics of natural gas at gas metering units. The draft Rules for determining the natural gas volume are considered in detail. Specified variants of determining the weighted average value of combustion heat in the case of complex gas supply systems with the use of flow measuring means of gas combustion heat. The necessity and urgency of determining the natural gas heat combustion on measuring systems, which are equipped with duplicate metering units without the installation flow means measuring the heat combustion. Emphasis is placed on the fact that a large number of measuring systems are built on the method of variable pressure drop with the use of standard orifice devices. It is pointed out that this method, according to its physical principle, measures the mass gas flow rate. It is also stipulated that ultrasonic gas meters are often used to complete duplicate metering units. The advantages of ultrasonic meters are given. Attention is drawn to the availability of technical metrological support in Ukraine on the basis calibration prover, which includes two secondary standards gas volume and volume flow rate units. Methods and technical means for determining the natural gas heat combustion are analyzed. The calculation of the gas heat combustion and the Wobbe number based on the density values is shown. It is noted that the value of the gas mass flow rate is related to the value of the gas volume flow rate precisely the value of density. The nonlinear dependence of the gas mass heat combustion for the density, which is associated with a disproportionate change in the percentage of carbon atoms to hydrogen atoms, is shown. The structural scheme of the measuring system with the duplicating metering unit for gas density definition and gas heat combustion calculation is developed. The density calculation and natural gas heat combustion depending on the molar fraction of nitrogen and carbon dioxide in the gas from the minimum to the maximum value is carried out. The linear dependence of the change in the gas heat combustion for the molar fraction of nitrogen is established, on the basis of which the method of controlling the gas heat combustion for measuring systems with a duplicate metering unit is proposed. It is shown that the developed procedure for determining the natural gas heat combustion based on the value of density, which is obtained from the calculation of gas mass flow rate and gas volume flow rate consumption on measuring systems with duplicate metering units exactly satisfies class B and C according to DSTU OIML R 140.

Theoretical Analyses of Heat Balance in a Diesel/Natural Gas Dual-Fuel Engine at Low and Medium Loads Based on Experimental Values

2020 ◽  
Vol 142 (5) ◽  
Author(s):  
Zhongshu Wang ◽  
Guizhi Du ◽  
Ming Li ◽  
Yun Xu ◽  
Fangyuan Zhang
Keyword(s):  
Heat Transfer ◽  
Natural Gas ◽  
Thermal Efficiency ◽  
Hot Water ◽  
Energy Utilization ◽  
Dual Fuel ◽  
Exergy Destruction ◽  
Energy Fraction ◽  
Combustion Heat ◽  
Diesel Injection

Abstract In order to propose the control strategies based on exergy to realize efficient and energy-saving operation of the engine, the energy and exergy balance under sensitive boundary conditions were analyzed with the first and second laws of thermodynamics on a six-cylinders, four strokes, turbocharged, intercooled, and high-pressure common rail diesel/natural gas (NG) dual-fuel engine in this paper. The results depicted that the thermal efficiency and exergy efficiency decrease with the increase of NG percentage energy substitution rate (PES). Compared with other conditions, at medium load, 1978 rpm and 90% PES, the exergy destruction caused by irreversibility process including mixing combustion, heat transfer and mechanical friction reaches 72.33%. With the advance of diesel injection time (Tinj), thermal efficiency and energy fraction of heat transfer increase first and then decrease. However, diesel injection pressure (Pinj) has little effect on improving energy utilization. Compared with single diesel injection, appropriate multiple diesel injection can improve combustion performance and energy utilization. When the first Tinj is 35 deg CA BTDC and second Tinj is 25 deg CA BTDC, nearly 50% of the energy lost in heat transfer can be converted into useful work. The lost exergy can be reduced by choosing appreciate Tinj and Pinj, adding exhaust gas recirculation (EGR) to reduce in-cylinder temperature to improve combustion and using thermal insulation materials to reduce heat transfer or using the lost heat in other processes such as preheating intake air and producing the hot water or steam of external consumption to reduce the exergy destruction.

Review of Theory and Practice on Natural Gas Hydrate

2011 ◽  
Vol 361-363 ◽  
pp. 149-160
Author(s):  
Bing Xiang Huang ◽  
Wei Chao Xue ◽  
You Zhuang Wang ◽  
Tong Zhang
Keyword(s):  
Natural Gas ◽  
Gas Hydrate ◽  
Clean Energy ◽  
High Energy ◽  
Research Field ◽  
Theory And Practice ◽  
High Energy Density ◽  
Natural Gas Hydrate ◽  
Combustion Heat ◽  
The World

Research on Natural Gas Hydrate（NGH）is very popular in recent years. NGH is a potential, new and clean energy with the characteristics of high energy density, high combustion heat, high proven reserves, no pollution, wide distribution and shallow burial and so on. It has been identified that NGH is widely distributed in the plateau, arctic permafrost and some eligible areas in the seabed of epicontinental and continental slope all around the world. According to the research data on NGH at home and abroad, the mineralizing, formation, distribution and exploration technology of NGH are introduced as well as the NGH research status of countries in the world, including China. Many theories and techniques about the exploitation of NGH are not mature yet. Numerous problems still exist in industrial mining NGH, such as environmental, geological problems induced by mining NGH and storage and transportation problems after mining. Finally, the application and mining prospects of NGH are and prospected and summarized to provide a relatively comprehensive reference to this research field.

Determination of the calorific value of natural gas using predictive modelling

2021 ◽  
Vol 103 (3) ◽  
pp. 110-116
Author(s):  
Halyna Kuz ◽  
Leonid Zamikhovskyi ◽  
Vitalii Shulha ◽  
Mykola Kuz
Keyword(s):  
Mathematical Model ◽  
Natural Gas ◽  
Predictive Modeling ◽  
Physical Quantity ◽  
Measurement Data ◽  
Calorific Value ◽  
Measured Data ◽  
Sufficient Accuracy ◽  
Combustion Heat

The analysis of the measured data on the calorific value of natural gas in different regions of Ukraine for 2014–2019, which are in the public domain, has been carried out. Since 2020, such data has not been published. This predetermines the need to use calculation methods for determining this physical quantity for subsequent years in different regions of Ukraine. It is proved that during 2018–2019 there was a trend for the stability of calorific value of natural gas, and fluctuations of calorific value had a smaller amplitude (within the range of 9.31–9.80 kW·h/m3), the spread in the values of the calorific value almost halved: from 0.88 to 0.49 kW·h/m3 compared to 2014–2017. Therefore, the measured data for the calorific value of natural gas for the period 2018–2019 were taken as a basis for predictive modeling of this physical quantity. It has been established that for most regions of Ukraine it is possible to use a single average value of the calorific value of natural gas for the subsequent determination of the energy of this energy carrier. The exceptions are Donetsk, Ivano-Frankovsk, Lugansk and Chernivtsi regions, in which the measurement data of the calorific value of natural gas are described with sufficient accuracy by the trigonometric cosine function. By the method of predictive modeling, a mathematical model has been developed to determine the calorific value of natural gas for a specific month of the year in Ukraine. The adequacy of the developed model has been verified by the example of measuring data on the calorific value of natural gas along route 406 (Ivano-Frankivsk region). It was found that the relative error in calculating the combustion heat of natural gas on this route does not exceed plus 1, minus 3%, which is comparable with the accuracy of measuring the volume of natural gas with household gas meters (the volume of gas and its heat of combustion are parameters for determining the energy of natural gas). Thus, a predictive mathematical model has been developed with sufficient accuracy to describe the change in the calorific value of natural gas and can serve as a basis for calculating this gas parameter in the absence of measurement data.

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