SCIENTIFIC AND ENGINEERING PRINCIPLES OF EFFICIENT FUEL USE AND ENVIRONMENTALLY FRIENDLY GAS COMBUSTION IN STOVE PLATES. PART 1. MODERN STATE-OF-THE-ART AND DIRECTIONS FOR IMPROVEMENT THE GAS BURNING IN DOMESTIC GAS COOKERS

2017 ◽  
pp. 3-18 ◽  
Author(s):  
B.S. Soroka ◽  
V.V. Horupa
Keyword(s):  
Natural Gas ◽  
Flow Rate ◽  
Gas Flow ◽  
Renewable Energy Sources ◽  
Combustion Process ◽  
Orifice Diameter ◽  
Firing Process ◽  
Gas Flow Rate ◽  
Gas Combustion ◽  
Gas Stoves

Natural gas NG consumption in industry and energy of Ukraine, in recent years falls down as a result of the crisis in the country’s economy, to a certain extent due to the introduction of renewable energy sources along with alternative technologies, while in the utility sector the consumption of fuel gas flow rate enhancing because of an increase the number of consumers. The natural gas is mostly using by domestic purpose for heating of premises and for cooking. These items of the gas utilization in Ukraine are already exceeding the NG consumption in industry. Cooking is proceeding directly in the living quarters, those usually do not meet the requirements of the Ukrainian norms DBN for the ventilation procedures. NG use in household gas stoves is of great importance from the standpoint of controlling the emissions of harmful components of combustion products along with maintenance the satisfactory energy efficiency characteristics of NG using. The main environment pollutants when burning the natural gas in gas stoves are including the nitrogen oxides NOx (to a greater extent — highly toxic NO2 component), carbon oxide CO, formaldehyde CH2O as well as hydrocarbons (unburned UHC and polyaromatic PAH). An overview of environmental documents to control CO and NOx emissions in comparison with the proper norms by USA, EU, Russian Federation, Australia and China, has been completed. The modern designs of the burners for gas stoves are considered along with defining the main characteristics: heat power, the natural gas flow rate, diameter of gas orifice, diameter and spacing the firing openings and other parameters. The modern physical and chemical principles of gas combustion by means of atmospheric ejection burners of gas cookers have been analyzed from the standpoints of combustion process stabilization and of ensuring the stability of flares. Among the factors of the firing process destabilization within the framework of analysis above mentioned, the following forms of unstable combustion/flame unstabilities have been considered: flashback, blow out or flame lifting, and the appearance of flame yellow tips. Bibl. 37, Fig. 11, Tab. 7.

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).

scholarly journals Improving the blast furnace process by raising the natural gas flow rate in the upper heat exchnage stage

2017 ◽  
Vol 15 (1) ◽  
pp. 37-44 ◽  
Author(s):  
Salavat K. Sibagatullin ◽  
◽  
Aleksandr S. Kharchenko ◽  
Vitaly A. Beginyuk ◽  
Valentin N. Selivanov ◽  
...  
Keyword(s):  
Blast Furnace ◽  
Natural Gas ◽  
Flow Rate ◽  
Gas Flow ◽  
Blast Furnace Process ◽  
Gas Flow Rate ◽  
Furnace Process ◽  
Natural Gas Flow

Study on the Kinetics of Chemical Looping Combustion of Copper-Based Oxygen Carrier

2013 ◽  
Vol 724-725 ◽  
pp. 1140-1144
Author(s):  
Yong Qiang Liu ◽  
Zhi Qi Wang ◽  
Jing Li Wu ◽  
Jin Hu Wu
Keyword(s):  
Particle Size ◽  
Reaction Temperature ◽  
Flow Rate ◽  
Conversion Rate ◽  
Gas Flow ◽  
Oxygen Carrier ◽  
Combustion Process ◽  
Chemical Looping Combustion ◽  
Chemical Looping ◽  
Gas Flow Rate

Kinetics is the study of rates of chemical processes, which includes investigations of how different experimental conditions can influence the speed of a chemical reaction and the reactions mechanism. In this paper, the influences of several parameters including particle size and mass of copper-based oxygen carrier, reaction gas flow rate and temperature on the conversion rate of oxygen carrier in chemical looping combustion was investigated. The results of experiment reveal that the conversion rate of oxygen carrier is influenced by the reaction temperature, mass of the oxygen carrier and the reaction gas flow rate. The conversion rate of oxygen carrier is improved with decreasing the mass of the oxygen carrier and increasing the reaction gas flow rate within a certain extent in the chemical looping combustion process. The particle size has very little effect on the conversion rate, and 800 °C is an advisable reaction temperature for chemical looping combustion process of copper-based oxygen carrier with methane and air.

scholarly journals Dynamic Characteristics of Offshore Natural Gas Hydrate Dissociation by Depressurization in Marine Sediments

Geofluids ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Xinfu Liu ◽  
Chunhua Liu ◽  
Jianjun Wu
Keyword(s):  
Natural Gas ◽  
Water Flow ◽  
Marine Sediments ◽  
Flow Rate ◽  
Gas Flow ◽  
Water Flow Rate ◽  
Water Production ◽  
Gas Flow Rate ◽  
Natural Gas Hydrate ◽  
Natural Gas Flow

Dynamic characteristics of offshore natural gas hydrate (NGH) dissociation will provide the theoretical basis to analyze technical issues of oceanic hydrate exploitation. A mathematical model is developed to simulate offshore NGH dissociation by depressurization in marine sediments. Different phase combination statuses are involved in the process of NGH dissociation by taking ice melting and water freezing into account. The proposed methodology can analyze the processes of hydrate and water phase transitions, decomposition kinetics and thermodynamics, viscosity and permeability, ice-water phase equilibrium, and natural gas and water production. A set of an experimental system is built and consists of one 3-D visual reactor vessel, one isothermal seawater vessel, one natural gas and water separator, and one data acquisition unit. The experiments on offshore NGH dissociation by depressurization in 3-D marine sediments are carried out, and this methodology is validated against the full-scale experimental data measured. The results show that during the prophase, natural gas flow is preceded by water flow into the production wellbore and natural gas occupies more continuous flow channels than water under a large pressure gradient. Then, the natural gas flow rate begins to decline accompanied by an increase of water production. During the second phase, natural gas flow rate decreases slowly because of the decreased temperature of hydrate-bearing formation and low pressure gradient. The lower the intrinsic permeability in marine sediments, the later the water flow rate reaches the peak production. And the space interval of the production wellbore should be enlarged by an increase of the intrinsic permeability. The stable period of natural gas production enhances, and the water flow rate reduces with the increase of bottom-hole pressure in production wellbores. The main reason is the slow offshore NGH dissociation under the low producing pressure and the restriction of heat conductivity under the low temperature.

Static performance of the aerostatic journal bearing with grooves

2019 ◽  
Vol 234 (7) ◽  
pp. 1114-1130
Author(s):  
Xinglong Chen ◽  
James K Mills ◽  
Gang Bao
Keyword(s):  
Flow Rate ◽  
Gas Flow ◽  
Journal Bearing ◽  
Load Capacity ◽  
Groove Depth ◽  
Load Force ◽  
Orifice Diameter ◽  
Geometrical Parameters ◽  
Gas Flow Rate ◽  
Static Performance

Aerostatic bearings are widely employed in precision machines due to their properties of low friction, low heat conduction, and long-life operation. In this work, static performance of the journal bearing with rectangular grooves is investigated numerically. The effect of geometrical parameters such as axial groove length [Formula: see text], circumferential groove length [Formula: see text], orifice diameter df, groove depth gh, misalignment angles [Formula: see text] and [Formula: see text] on the load capacity [Formula: see text], stiffness [Formula: see text], and gas flow rate [Formula: see text] are analyzed systematically. The resistance network method (RNM) is utilized to solve the Reynolds equation required in the analysis. Performance parameters including pressure distribution P, load force [Formula: see text], stiffness [Formula: see text], and gas flow rate [Formula: see text] are examined in the simulations. It is revealed from the simulations that the proper value of axial groove length [Formula: see text] to obtain a better static performance varies from 1/8 to 1/2 when df varies between 0.11 and 0.29 mm, respectively. Therefore, a larger load force and stiffness can be obtained if [Formula: see text] is chosen to be 1/4, when diameter of the bearing orifice df equals 0.17 mm. It is also suggested that [Formula: see text] be chosen from the range of 1/6 and 1/3 to obtain a better static performance and a smaller gas flow rate. [Formula: see text] decreases with an increase in df when [Formula: see text] is set to be 1/8. However, the load force [Formula: see text] increases with an increase in df when [Formula: see text] varies from 3/8 to 1/2. [Formula: see text] has a significant influence on the changes of [Formula: see text] with df when [Formula: see text] is set to be constant. Therefore, df should be selected according to [Formula: see text] for an optimal design. The increase of misalignment angle [Formula: see text] leads to an increase in the load force [Formula: see text]. [Formula: see text] has little influence on the load force [Formula: see text]. Misalignment angles [Formula: see text] and [Formula: see text] have little influence on stiffness [Formula: see text] and gas flow rate [Formula: see text]. Therefore, it is preferable if [Formula: see text] is larger than 0 rad.

The Physical Characteristics of Bio-Oil from Fast Pyrolysis of Rice Straw

2011 ◽  
Vol 328-330 ◽  
pp. 881-886 ◽  
Author(s):  
Shou Yin Yang ◽  
Chih Yung Wu ◽  
Kun Ho Chen
Keyword(s):  
Rice Straw ◽  
Flow Rate ◽  
Gas Flow ◽  
Ph Value ◽  
Renewable Energy Sources ◽  
Fast Pyrolysis ◽  
Gas Flow Rate ◽  
Carrier Gas ◽  
Bio Oil ◽  
Carrier Gas Flow

Rice straw is one of the main renewable energy sources in central and south Taiwan. In this study, bio-oil was produced from rice straw using a bench-scale plant that included a fluidized bed, a char removal system, and an oil collection system using an oil-recycling spray condenser. We investigated the effects of pyrolysis temperature and carrier gas flow rate on the distribution of products and on the properties of the bio-oil obtained. Experiments were conducted at reactor temperatures of 350–500 °C with carrier gas flow rates of 7.5–15 L/min and a feed rate of 1 kg/h. The results indicated that the optimum reaction temperature and carrier gas flow rate for the production of bio-oil were 450 °C and 10 L/min, respectively. The highest percentage of bio-oil in the products in these experiments was 41.3 wt%. The pH value of the bio-oil was ~4.1 and the viscosity was ~9 cSt (at 25 °C), depending on the storage time, temperature, and char content. This study establishes the operating parameters of a biomass fast pyrolysis system and provides some properties of rice straw bio-oil relevant to storage and use.

Simulation of CO2 removal from pressurized natural gas stream contains high CO2 concentration by absorption process using membrane contactors

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Hamza A. Ahmed ◽  
Harith N. Mohammed ◽  
Omar S. Lateef ◽  
Ghassan H. Abdullah
Keyword(s):  
High Pressure ◽  
Natural Gas ◽  
Removal Efficiency ◽  
Flow Rate ◽  
Contact Area ◽  
Gas Flow ◽  
Membrane Properties ◽  
Operating Pressure ◽  
Gas Flow Rate ◽  
Membrane Contactors

AbstractDespite the importance of natural gas (NG) as an energy source, there is a lot of pressurized landfill gas not exploited so far because it contains high CO2 concentration. Therefore, this study aimed to develop a 2-D mathematical model to simulate CO2 removal from NG stream contains high CO2 concentration up to 70% at high-pressure up to 60 bar using three different dimensions of polyvinylidene fluoride (PVDF) hollow fiber membrane contactors. Aqueous solutions of activated methyldiethanolamine (MDEA) with piperazine (PZ) were adopted. The performance of considered absorbent at high-pressure was evaluated at the non-wetting mode condition of membrane contactor. Moreover, the effect of pressure, contact area, gas flow rate, MDEA concentration into the amine mixture, PZ concentration, temperature and membrane properties were theoretically investigated. The findings stated that activated MDEA had different performance in terms of membrane wetting compared with other amines, which used at high pressure in previous studies. In addition, the simulation results showed that CO2 removal efficiency was significantly enhanced, when the operating pressure, contact area, PZ concentration and temperature were increased. However, increasing gas flow rate leads to reduce CO2 removal efficiency. Furthermore, the CO2 absorption was significantly improved by adding a small amount of PZ to MDEA. The predicted model results showed a good agreement with experimental data obtained from the literature.

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