scholarly journals Удосконалення процесу сумішоутворення в камерах згоряння теплових двигунів

2021 ◽  
pp. 29-34
Author(s):  
Ирина Владимировна Морозова ◽  
Юрий Матвеевич Терещенко
Keyword(s):  
Combustion Chamber ◽  
Fuel Efficiency ◽  
Experimental Studies ◽  
Hydrocarbon Fuel ◽  
Fuel Combustion ◽  
Main Process ◽  
Gas Temperature ◽  
Operating Cycle ◽  
Environmental Friendliness ◽  
Working Cycle

Improving the mixture formation and combustion of various types of fuels in the combustion chamber is one the ways for the development of modern engines. Requirements for reliability, durability, tactical and technical characteristics and, importantly, for environmental friendliness pose new problems in this area of science and technology. This is largely determined by the degree of perfection individual processes in the engine operating cycle. An increase in power in accordance with the requirements for an increase in energy saturation and productivity of transport vehicles is limited by the resource and reliability of the engine due to an increase in thermal and mechanical loading of the main parts. The expansion the scope of application is limited by increased emissions harmful substances with exhaust gases, levels noise and vibration a running engine. Consumption increasing amounts liquid fuels requires further improvements in fuel efficiency. The main process of the working cycle a piston engine is the process fuel combustion. Fuel efficiency, power, service life and environmental performance depend on its quality. Therefore, the greatest attention is paid to the improvement of this process. The development of modern engines consists in the study and improvement of the working process on liquid and gaseous fuel components. Based on the foregoing and in accordance with the urgency of this problem, the method of electromagnetic action on fuel was studied. The results of experimental studies have shown the effectiveness the use of electro physical effects on hydrocarbon fuel to improve the parameters and characteristics of heat engines. It has been established that the electro physical effect on hydrocarbon fuel increases the completeness of fuel combustion by 4 ... 6% and reduces the deposition of carbon deposits in the combustion chamber of a gas turbine engine by 20 ... 25%. Improvement the fuel combustion processes in the previous phases leads to a reduction in the afterburning phase, which entails a decrease in the exhaust gas temperature, a decrease in the concentration of carbon monoxide by 0.64 ... 0.7%, the concentration of hydrocarbons by 25 ... 35% and the concentration of nitrogen oxide by 12 ... 16%.

scholarly journals IMPROVING FUEL EFFICIENCY OF MARINE SWIRL-CHAMBER DIESEL ENGINE BY INCREASED THERMAL RESISTANCE OF HEAT TRANSFER

2019 ◽  
pp. 80-87
Author(s):  
Alexander Fedorovich Dorokhov ◽  
Pavel Aleksandrovitch Dorokhov
Keyword(s):  
Heat Transfer ◽  
Diesel Engine ◽  
Thermal Resistance ◽  
Combustion Chamber ◽  
Fuel Consumption ◽  
Diesel Engines ◽  
Fuel Efficiency ◽  
Working Fluid ◽  
Gas Temperature ◽  
Swirl Chamber

The article considers ship swirl-chamber diesel engines used in shipbuilding as the main and auxiliary engines. Two reasons for low profitability of the swirl chamber diesel engines are highlighted: large heat losses of the cooling working fluid due to the extended heat transfer surface of the chamber, and significant aerodynamic energy losses of compressed air during its passage through a relatively narrow channel connecting the piston chamber with the combustion chamber and the flow of gases from the swirl chamber on top the piston space. There have been proposed the methods for improving the operational performance of swirl-chamber diesels in production, in particular, their fuel efficiency. The scheme of the swirl-chamber and a section of the swirl-chamber cylinder head are presented. It has been stated that the total coefficient of thermal conductivity can be reduced if the wall of the swirl- chamber is made multi-layer. The layouts of a multi-layer cylinder-spherical wall of a swirl combustion chamber with a titanium cylinder-spherical insertion and thermal insulation of a vortex combustion chamber are given. The total thermal resistance of the spherical wall was calculated, heat loss through the multilayer spherical wall was determined, gas temperature in the vortex chamber was calculated, according to the average cycle temperature diagram. It was inferred that the amount of heat removed from the working fluid to cooling through the thermally insulated wall of the swirl-chamber will be 40% less than the amount of heat released to the cooling through the wall of the swirl-chamber of a commercial diesel engine. The difference in heat will be used to increase the indicator gas operation, which, with the same cyclic fuel supply, will lead to a decrease in the specific indicator fuel consumption, and at a constant level of internal engine losses - to a decrease in the specific effective fuel consumption.

Influence of the distribution of fuel supply in a double-circuit burner on the concentration of harmful substances in combustion products

2021 ◽  
pp. 10-13
Author(s):  
A.V. Baklanov
Keyword(s):  
Nitrogen Oxides ◽  
Combustion Chamber ◽  
Experimental Studies ◽  
Combustion Products ◽  
Combustion Efficiency ◽  
Fuel Combustion ◽  
Minimum Concentration ◽  
Fuel Supply ◽  
Low Emission ◽  
Harmful Substances

The design of a double-circuit burner of a low-emission combustion chamber of a gas turbine engine working on natural gas is considered. The distribution of the fuel supply in the double-circuit burner is investigated and its influence on the emissions of harmful substances is determined. Bench equipment, features of experimental studies of the concentration of gas mixture components in combustion products and calculations of the fuel combustion efficiency are presented. The ratio of fuel consumption along the circuits at a minimum concentration of nitrogen oxides and maximum combustion efficiency of carbon oxide in combustion products is determined. Keywords: double-circuit burner, low-emission combustion chamber, experiment, fuel, combustion efficiency, combustion products, nitrogen oxides. [email protected]

Investigation on wall and gas temperatures inside a swirled oxy-fuel combustion chamber using thermographic phosphors, O2 rotational and vibrational CARS

Fuel ◽  
2021 ◽  
Vol 289 ◽  
pp. 119787
Author(s):  
Christian Meißner ◽  
Henrik Schneider ◽  
Evaggelos Sidiropoulos ◽  
Jonas I. Hölzer ◽  
Tim Heckmann ◽  
...  
Keyword(s):  
Combustion Chamber ◽  
Fuel Combustion ◽  
Thermographic Phosphors

Experimental Studies on Diesel Engine with Piston Crown Modification Using an Optimum Alternative Fuel

2015 ◽  
Vol 813-814 ◽  
pp. 830-835
Author(s):  
Akkaraju H. Kiran Theja ◽  
Rayapati Subbarao
Keyword(s):  
Diesel Engine ◽  
Combustion Chamber ◽  
Experimental Studies ◽  
Alternative Fuel ◽  
Air Gap ◽  
The Body ◽  
Injection Timing ◽  
Positive Trend ◽  
Piston Crown ◽  
Karanja Oil

The drawbacks associated with bio-fuels can be minimized by making modifications to combustion chamber. Modification of combustion chamber is achieved by providing an air gap in between the crown and the body of the piston with the top crown made of low thermal conductivity material. Experimentation is carried on a diesel engine with brass as piston crown material and karanja as test fuel, which is found to be a better alternative fuel based on the tests carried out prior to modification. Investigations are carried out on the performance of the engine with modified combustion chamber consisting of air gap insulated piston with 2 mm air gap with brass crown when fuelled with karanja oil. Comparative studies are made between the two configurations of engine with and without modification at an injection timing of 29obTDC. Performance, heat balance and emission plots are made with respect to brake power. Fuel consumption increased with modification. The mechanical and volumetric efficiencies are similar in both the cases. Indicated and brake thermal efficiencies got reduced with modification. But, it is good to see that HC and CO emissions are showing positive trend. Thus, the present investigation hints the possibility of improvements while making piston modification and providing air gap insulation.

Stabilization of liquid hydrocarbon fuel combustion by using a programmable microwave discharge in a subsonic airflow

2012 ◽  
Vol 38 (6) ◽  
pp. 503-512 ◽  
Author(s):  
P. V. Kopyl ◽  
O. S. Surkont ◽  
V. M. Shibkov ◽  
L. V. Shibkova
Keyword(s):  
Microwave Discharge ◽  
Hydrocarbon Fuel ◽  
Liquid Hydrocarbon ◽  
Fuel Combustion

Turbine Split Rings Thermal Design Using Conjugate Numerical Simulation

2013 ◽  
Author(s):  
Aleksei S. Tikhonov ◽  
Andrey A. Shvyrev ◽  
Nikolay Yu. Samokhvalov
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Gas Turbine ◽  
Gas Dynamics ◽  
Thermal Condition ◽  
Fuel Efficiency ◽  
Thermal Design ◽  
Design Practice ◽  
Gas Temperature ◽  
Split Ring

One of the key factors ensuring gas turbine engines (GTE) competitiveness is improvement of life, reliability and fuel efficiency. However fuel efficiency improvement and the required increase of turbine inlet gas temperature (T*g) can result in gas turbine engine life reduction because of hot path components structural properties deterioration. Considering circumferential nonuniformity, local gas temperature T*g can reach 2500 K. Under these conditions the largest attention at designing is paid to reliable cooling of turbine vanes and blades. At present in design practice and scientific publications comparatively little attention is paid to detailed study of turbine split rings thermal condition. At the same time the experience of modern GTE operation shows high possibility of defects occurrence in turbine 1st stage split ring. This work objective is to perform conjugate numerical simulation (gas dynamics + heat transfer) of thermal condition for the turbine 1st stage split ring in a modern GTE. This research main task is to determine the split ring thermal condition by defining the conjugate gas dynamics and heat transfer result in ANSYS CFX 13.0 package. The research subject is the turbine 1st stage split ring. The split ring was simulated together with the cavity of cooling air supply from vanes through the case. Besides turbine 1st stage vanes and blades have been simulated. Patterns of total temperature (T*Max = 2000 °C) and pressure and turbulence level at vanes inlet (19.2 %) have been defined based on results of calculating the 1st stage vanes together with the combustor. The obtained results of numerical simulation are well coherent with various experimental studies (measurements of static pressure and temperature in supply cavity, metallography). Based on the obtained performance of the split ring cooling system and its thermal condition, the split ring design has been considerably modified (one supply cavity has been split into separate cavities, the number and arrangement of perforation holes have been changed etc.). All these made it possible to reduce considerably (by 40…50 °C) the split ring temperature comparing with the initial design. The design practice has been added with the methods which make it possible to define thermal condition of GTE turbine components by conjugating gas dynamics and heat transfer problems and this fact will allow to improve the designing level substantially and to consider the influence of different factors on aerodynamics and thermal state of turbine components in an integrated programming and computing suite.

SPECTRAL DIAGNOSTICS OF THE HYDROCARBON FUEL COMBUSTION PROCESS

2021 ◽  
pp. 12-17
Author(s):  
M. A. Vaganov
Keyword(s):  
Combustion Process ◽  
Hydrocarbon Fuel ◽  
Combustion Products ◽  
Combustible Mixture ◽  
Fuel Combustion ◽  
Propane Combustion ◽  
Gaseous Hydrocarbon ◽  
Spectral Bands ◽  
Air Supply ◽  
Spectral Diagnostics

It is proposed to use the methods of applied optical spectroscopy to solve the problem of control and diagnostics of gaseous hydrocarbon fuel combustion in this work. The results of an experimental study of spectroscopic informative parameters characterizing the propane combustion process are presented for three modes: combustion of pure propane without air supply, stoichiometric combustion and combustion with a change in the amount of supplied air relative to stoichiometric combustion. As a result of the experiment, it was found that the most intense bands in the emission spectrum of the flame arising from the combustion of propane correspond to the spectral bands of radicals of combustion products: OH, CH, and C2. While the intensities of various systems of bands in the flame spectrum depend significantly on the composition of the combustible mixture.

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