scholarly journals Study of the influence of temperature on the parameters of natural fuel gas

2021 ◽  
Vol 36 ◽  
pp. 52-60
Author(s):  
V. Konovaliuk ◽  
Yu. Yu. Franchuk
Keyword(s):  
Natural Gas ◽  
Combustion Products ◽  
Heat Of Combustion ◽  
Fuel Gas ◽  
Energy Value ◽  
Normative Documents ◽  
Influence Of Temperature On ◽  
Wobbe Index ◽  
Definition Of ◽  
Gas Volume

Differences in normative documents on the definition of "standard conditions" and parameters at which the heat of combustion of natural gas is determined are analyzed. When determining the energy value of natural gas in European countries, different values of the final temperature of combustion products, values of higher or lower heat of combustion are used. This causes a deviation of up to 19 % of the values of the heat of combustion of natural gas of the same composition, depending on the standard conditions established in a particular country. The dynamics of temperature change in some sections of the network and its influence on the determination of gas volumes were studied on the example of the urban-type settlement of Yampil, Khmelnytsky region. On the basis of actual values of the basic gas parameters in characteristic pointss of the settlement network, influence of ambient temperature on the basic parameters of the gas is investigated. Graphical dependences of gas density, Wobbe index, and gas volume on temperature are constructed. Based on the calculations, it was determined that when the temperature changes in the range from 0 to 40 °C, the volume of gas increases by 0.34 m3 per 1 °C. The density decreases by 0.002 kg/m3 per 1 °C. The maximum value of the Wobbe index is reached at temperatures of 10 and 25 °C. The same volume of gas can have different energy value, as it directly depends on the composition and percentage of the components of the gas mixture. There are special metters, which analyze the gas components. But they are installed only at large consumers. The presence of a corrector for temperature and pressure at the gas metering unit allows to increase the reliability of metering, but does not completely solves the problem. The amount of gas measured by the meters must be brought to standard conditions and converted into units of energy.

scholarly journals Impact of Grid Gas Requirements on Hydrogen Blending Levels

2021 ◽  
Vol 25 (1) ◽  
pp. 688-699
Author(s):  
Eduard Latõšov ◽  
Ieva Pakere ◽  
Lina Murauskaite ◽  
Anna Volkova
Keyword(s):  
Natural Gas ◽  
Specific Gravity ◽  
Hydrogen Content ◽  
Calorific Value ◽  
Quality Parameters ◽  
Heat Of Combustion ◽  
Gas Network ◽  
Technical Requirements ◽  
Wobbe Index ◽  
Methane Number

Abstract The aim of the article is to determine what amount of hydrogen in %mol can be transferred/stored in the Estonian, Latvian and Lithuanian grid gas networks, based on the limitations of chemical and physical requirements, technical requirements of the gas network, and quality requirements. The main characteristics for the analysis of mixtures of hydrogen and natural gas are the Wobbe Index, relative density, methane number, and calorific value. The calculation of the effects of hydrogen blending on the above main characteristics of a real grid gas is based on the principles described in ISO 6976:2016 and the distribution of the grid gas mole fraction components from the grid gas quality reports. The Wärtsila methane number calculator was used to illustrate the effects of hydrogen blending on the methane number of the grid gas. The calculation results show that the maximum hydrogen content in the grid gas (hydrogen and natural gas mix), depending on the grid gas quality parameters (methane number, gross heat of combustion, specific gravity, and the Wobbe Index), is in the range of 5–23 %mol H2. The minimum hydrogen content (5 %mol H2) is limited by specific gravity (>0.55). The next limitation is at 12 %mol H2 and is related to the gross heat of combustion (>9.69 kWh/m3). It is advisable to explore the readiness of gas grids and consumers in Estonia, Latvia and Lithuania before switching to higher hydrogen blend levels. If the applicability and safety of hydrogen blends above 5 %mol is approved, then it is necessary to analyse the possible reduction of the minimum requirements for the quality of the grid gas and evaluate the associated risks (primarily related to specific gravity).

Further studies of the role of radiative ignition in the propagation of large explosions

1987 ◽  
Vol 409 (1836) ◽  
pp. 1-20 ◽  
Keyword(s):  
Combustion Products ◽  
Theoretical Modelling ◽  
Combustion Properties ◽  
Radiation Induced ◽  
Path Lengths ◽  
Basic Hypothesis ◽  
Definition Of ◽  
Explosive Composition ◽  
Radiance Distribution ◽  
Gas Volume

Following previous work demonstrating that the anomalously high rates of propagation of unconfined vapour cloud explosions could be caused, or aggravated, by radiation-induced multi-point ignition due to small fibrous particles ahead of the main flame front, the investigation is extended towards more practical criteria. Ignition lag measurements are carried out in various hydrocarbons, at different relative velocities between particle and mixture, in a radiation flux that is varied in magnitude, direction and range of wavelengths. An image furnace with a tungsten filament as source is used as an alternative to a CO 2 laser, to obtain a closer approximation to radiation from combustion products. Measurements on particles of clean insulating and cotton wool are complemented by more ‘practical’ dusts collected from, for example, vacuum cleaners and shelves. The spectral absorption of various particles is compared with the radiance distribution due to various path lengths of combustion products, and the effect of coating clean particles with lamp black (to simulate the effect of dirt) is assessed. The basic hypothesis is reassessed in terms of a more detailed theoretical model that allows for slip between particle and gas velocity, radiation from secondary ignition centres and a definition of flame speed based on the rate of product gas volume generation. It is found that the susceptibility of various hydrocarbons and mixtures to this type of ignition accords with other combustion properties such as ignition temperatures and burning velocities. While the absorp­tive properties of certain particles and the propensity of others to emit inert blanketing vapour renders them less effective in producing ignition in the laboratory, all particles become hazardous when blackened by dirt and particularly, when subjected to previous exposure to radiation while not surrounded by a mixture of explosive composition. Theoretical modelling confirms that flame speeds of the order required to account for the damage observed in practice are generated by this mechanism and that this result applies for surprisingly low concentrations of hazardous particles. Thus, given the facility with which agglomerates of fibres are raised in suspension and the likelihood of their presence in numbers sufficient for this mechanism, the hazard warning implied by the previous work is reinforced.

Experimental Study of a 200 kW Partial Oxidation Gas Turbine (POGT) for Co-Production of Power and Hydrogen-Enriched Fuel Gas

2009 ◽  
Author(s):  
Joseph Rabovitser ◽  
Stan Wohadlo ◽  
John M. Pratapas ◽  
Serguei Nester ◽  
Mehmet Tartan ◽  
...  
Keyword(s):  
Experimental Study ◽  
Gas Turbine ◽  
Partial Oxidation ◽  
Synthesis Gas ◽  
Combustion Products ◽  
Working Fluid ◽  
Fuel Gas ◽  
Lean Combustion ◽  
Start Up ◽  
Oxidation Reactor

Paper presents the results from development and successful testing of a 200 kW POGT prototype. There are two major design features that distinguish POGT from a conventional gas turbine: a POGT utilizes a partial oxidation reactor (POR) in place of a conventional combustor which leads to a much smaller compressor requirement versus comparably rated conventional gas turbine. From a thermodynamic perspective, the working fluid provided by the POR has higher specific heat than lean combustion products enabling the POGT expander to extract more energy per unit mass of fluid. The POGT exhaust is actually a secondary fuel gas that can be combusted in different bottoming cycles or used as synthesis gas for hydrogen or other chemicals production. Conversion steps for modifying a 200 kW radial turbine to POGT duty are described including: utilization of the existing (unmodified) expander; replacement of the combustor with a POR unit; introduction of steam for cooling of the internal turbine structure; and installation of a bypass air port for bleeding excess air from the compressor discharge because of 45% reduction in combustion air requirements. The engine controls that were re-configured for start-up and operation are reviewed including automation of POGT start-up and loading during light-off at lean condition, transition from lean to rich combustion during acceleration, speed control and stabilization under rich operation. Changes were implemented in microprocessor-based controllers. The fully-integrated POGT unit was installed and operated in a dedicated test cell at GTI equipped with extensive process instrumentation and data acquisition systems. Results from a parametric experimental study of POGT operation for co-production of power and H2-enriched synthesis gas are provided.

scholarly journals Definition of validated membrane reactor model for 5 kW power output CHP system for different natural gas compositions

2016 ◽  
Vol 41 (42) ◽  
pp. 19141-19153 ◽  
Author(s):  
Gioele Di Marcoberardino ◽  
Fausto Gallucci ◽  
Giampaolo Manzolini ◽  
Martin van Sint Annaland
Keyword(s):  
Natural Gas ◽  
Power Output ◽  
Membrane Reactor ◽  
Reactor Model ◽  
Chp System ◽  
Definition Of

Gas Turbine Combined Cycle With CO2-Capture Using Auto-Thermal Reforming of Natural Gas

2000 ◽  
Author(s):  
Thormod Andersen ◽  
Hanne M. Kvamsdal ◽  
Olav Bolland
Keyword(s):  
Natural Gas ◽  
Gas Turbine ◽  
Process Integration ◽  
Combined Cycle ◽  
Co2 Removal ◽  
Gas Turbine Combustor ◽  
Chemical Absorption ◽  
Fuel Gas ◽  
The Impact ◽  
Water Gas

A concept for capturing and sequestering CO2 from a natural gas fired combined cycle power plant is presented. The present approach is to decarbonise the fuel prior to combustion by reforming natural gas, producing a hydrogen-rich fuel. The reforming process consists of an air-blown pressurised auto-thermal reformer that produces a gas containing H2, CO and a small fraction of CH4 as combustible components. The gas is then led through a water gas shift reactor, where the equilibrium of CO and H2O is shifted towards CO2 and H2. The CO2 is then captured from the resulting gas by chemical absorption. The gas turbine of this system is then fed with a fuel gas containing approximately 50% H2. In order to achieve acceptable level of fuel-to-electricity conversion efficiency, this kind of process is attractive because of the possibility of process integration between the combined cycle and the reforming process. A comparison is made between a “standard” combined cycle and the current process with CO2-removal. This study also comprise an investigation of using a lower pressure level in the reforming section than in the gas turbine combustor and the impact of reduced steam/carbon ratio in the main reformer. The impact on gas turbine operation because of massive air bleed and the use of a hydrogen rich fuel is discussed.

scholarly journals Reengineering of capital construction objects and reengineering of technological processes

Vestnik MGSU ◽  
2019 ◽  
pp. 1321-1330 ◽  
Author(s):  
Sergey B. Sborshikov ◽  
Lubov A. Maslova
Keyword(s):  
Construction Projects ◽  
Living Environment ◽  
Building Site ◽  
Normative Documents ◽  
Technological Processes ◽  
Functional Relations ◽  
Mutual Relations ◽  
Definition Of ◽  
Capital Construction ◽  
Corporate Level

Introduction. The article discusses two types of corporate-level reengineering of investment and construction activities: the qualitative transformation of capital construction projects (CCP) and technological processes. The implementation of the reengineering measures in respect of the CCP is studied as a dominant. All the mutual relations and interactions of anthropotechnical system elements and external environment are assembled around the CCP. The CCP is considered as the expression of the achieved result. Materials and methods. The study used legislative and normative documents regulating investment and construction activities in the Russian Federation as well as papers of domestic and foreign scientists. The examined normative and methodological materials allowed identifying criteria and factors of classification of reengineering measures at the level of “building project – building site” and on this basis establishing the composition of the reengineering of a CCP and reengineering of technological processes. Results. The article examines the normative component of the practical activity of the reengineering. It provides the following terms regulated by the current legislative base of construction: reconstruction, major repair, technical re-equipment, restoration. Separately, the definition of CCP reprofiling is suggested. Structural and functional relations within CCP and technological processes reengineering are studied. Conclusions. The research has demonstrated that the reengineering is an efficient mechanism of formation of a comfortable living environment based on achievements of science and technology, record and complete satisfaction of consumers’ demands, as well as the creation of competitive advantages for not only domestic construction establishments but also the whole national construction industry. All this made it possible to determine the genesis of the corporate level reengineering of investment and construction activities and to establish a structure of the CCP reengineering. In conclusion, the article presented the main directions for improving the efficiency of the reengineering mechanism. The role of information and analytical activity organization quality in this system of the measures is specially marked.

scholarly journals ANALYSIS OF METHODS AND MEASURES OF MEASUREMENT OF HEAT OF COMBUSTION OF NATURAL GAS IN UKRAINE AND ABROAD

2019 ◽  
pp. 78-87
Author(s):  
K. M. Shynkaruk
Keyword(s):  
Natural Gas ◽  
Calorific Value ◽  
Energy Performance ◽  
Heat Of Combustion ◽  
Indirect Methods ◽  
Global Trends ◽  
The Relationship ◽  
Direct And Indirect Methods ◽  
Qualitative Characteristics

In connection with the increase in prices for natural gas, the urgent issue is to calculate not only the amount of gas consumed, but also its quality precisely with the consumer. The quality of gas is the compliance of its physicochemical parameters with established regulatory documents. With the current gas accounting and payment system in Ukraine, consumers using the same number of cubic meters receive different heat of combustion. The paper analyzes the regulatory framework for assessing the energy performance of natural gas. The necessity of the transition to accounting for natural gas in energy units is substantiated. Existing methods and means for determining the calorific value of natural gas that are used in Ukraine and abroad are considered. Currently, direct and indirect methods are used to determine the calorific value of natural value of natural gas. The most common is the calculation method based on chromatographic analysis, the implementation of which requires expensive equipment. Other methods for determining the calorific value of natural gas is correlation. The essence of which is to establish the relationship between a certain physicochemical property of natural gas and calorific value, which can be established by experimental observations and based on theoretical analysis, which makes it possible to draw a conclusion about the calorific value of natural gas. Based on the analysis, it was found that currently there are no simple in design and not expensive means of controlling the qualitative characteristics of natural gas commercially available. Therefore, it is relevant to solve the problem of operational control of the quality of natural gas, through scientific justification, development and improvement of tools that enable the indirect accounting of the energy value of natural gas in accordance with global trends in energy accounting. A correlation analysis was carried out to establish the relationship between the thermal conductivity and the calorific value of natural gas. The use of the thermocatalytic method for determining the calorific value of gas is proposed, which will allow designing a relatively cheap and easy-to-use device for monitoring the quality of natural gas specifically for the consumer.

scholarly journals Guidelines for the Use of Voice Alarm Systems Based on the Analysis of Normative and Legal Documents Used in Selected European Countries

2021 ◽  
Vol 57 (1) ◽  
pp. 6-24
Author(s):  
Keyword(s):  
Speech Intelligibility ◽  
Research Evaluation ◽  
Fire Detection ◽  
Research Process ◽  
European Countries ◽  
Theoretical Research ◽  
Normative Documents ◽  
Legal Documents ◽  
Alarm Systems ◽  
Definition Of

Purpose: The aim of this publication is to present the results of theoretical research – evaluation of normative and legal documents used for the design and installation of voice alarm systems (VAS) in selected European countries. The aim of the research was to analyze and compare the functioning of voice alarm systems in Poland against the background of selected European countries. Introduction: Voice alarm systems are systems installed in buildings that enable the broadcast of warning signals and voice messages for the safety of people in the building. Mandatory use of voice alarm systems in selected buildings became applicable in Poland on January 16, 2006. In Europe, these systems have been present before. Over the years, there has been development of both the devices included in the systems, as well as the normative documents and legal acts that describe these systems. Methods: Within the research process, theoretical research was used, such as: analysis of literature and legal documents, synthesis, generalization, inference, comparison and analogy. As part of the research, documents from such countries as Poland, Great Britain (mainly England), Sweden, Norway, Germany and the Netherlands were analyzed. The selection of individual countries was guided by the level of development of these systems in a given country and the availability of source documents. Conclusions: The presented analysis of the requirements for the use of voice alarm systems shows how different the approach to the use of this type of systems is. Depending on individual experiences and the administrative structure of a given country, a variety of regulations, whether legal or normative (not always normative documents issued by state standardization institutions), can be seen in the field of voice alarm systems application. Unfortunately, one can get the impression that voice alarm systems are still not as popular as fire detection systems. The definition of the requirements for buildings in which the use of voice alarm systems should be obligatory and the requirements for the determination of the required level of speech intelligibility consti- tute the basis for the consistent development of this type of fire protection equipment. Such requirements should be specified either in legal regulations or in normative acts dedicated to voice alarm systems. Keywords: safety of evacuation, evacuation of buildings, voice alarm system, EN 54-16, EN 54-24, guidelines Type of article: review article

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