Adapting an Internal Combustion Engine to Oxy-Fuel Combustion With In-Situ Oxygen Production

2021 ◽  
Author(s):  
Francisco Arnau ◽  
Ricardo Novella ◽  
Luis Miguel García-Cuevas ◽  
Fabio Gutiérrez

Abstract In transport applications, reciprocating internal combustion engines still have important advantages in terms of endurance and refueling time and available infrastructure when compared against fuel cell or battery-based powertrains. Although conventional internal combustion engine configurations produce important amounts of greenhouse gases and pollutant emissions, oxyfuel combustion can be used to mitigate to a great extent such emissions, mainly producing NOx-free, CO2 and H2O exhaust gases. However, the oxygen needed for the combustion, which is mixed with flue gases before entering the cylinder, has to be stored in an additional tank, which hinders the adoption of this technology. Fortunately, the latest developments in gas separation membranes are starting to produce extremely-high selectivity and high permeability oxygen-separation membranes. Using the waste heat of the exhaust gases to heat up a mixed ionic-electronic conducting membrane, and feeding it with pressurized air, it is possible to produce all the oxygen needed by the combustion process while keeping the whole system compact. This works presents a design of an oxy-fuel combustion engine with in-situ oxygen production. The numerical simulations show also that this concept keeps a competitive brake specific fuel consumption, while the high concentration of CO2 in the exhaust gases facilitates the introduction of carbon sequestration technologies, leading to potentially carbon-neutral internal combustion engines.

2020 ◽  
Author(s):  
Chiriac Rares ◽  
Anghel Chiru

Abstract Internal combustion engines have an operating efficiency that can be exploited to increase their performance. Some of the waste gases can be recovered through technical solutions such as turbocharging. The turbocharging solution is one of the most popular technical solutions for increasing the energy performance of internal combustion engines. This requires an analysis of the energy balance of the internal combustion engine. This shows that there is a significant reserve of energy in the exhaust gases, which can be used to increase the engine efficiency. One solution is to use this energy to drive a turbine coupled with an electric generator. This article aims to present the result of the experimental research of the hybrid turbocharger, simulating and validating the new solutions for increasing the energy performance of internal combustion engines through hybrid turbochargers using a coupled electric generator. The simulations will be performed using AMESim software developed by Siemens to demonstrate through calculations the efficiency of new solutions, such as a hybrid turbocharger. The tests will be performed using an diesel internal combustion engine with a cylinder capacity of 1.9 liters which is also simulated with AMESim software. The residual exhaust gases of the internal combustion engine will drive the hybrid turbocharger turbine and generate electricity. Electricity can then be used for storage in the car battery or for consumption by the car's electrical system. The article also includes a comparative study between the power and torque of the naturally aspirated internal combustion engine equipped with a hybrid turbocharger.


Author(s):  
Yuriy Paladiychuk ◽  
Inna Telyatnuk

Mechanization of labor on small farms and individual farms is a very important issue of modern agriculture. The use of small agricultural machinery with a capacity of up to 16 kW is quite relevant today. Small-sized machinery is divided into: small 4-wheeled tractors, 2-wheeled motoblocks, cultivators, machines and equipment. With the help of this technique perform various agricultural and other types of work in crop production, horticulture, gardening on small plots, livestock and more. Despite its rather small size, small equipment also has various mechanisms that fail over time. Most often, the parts of the internal combustion engine fail. In general, the cost of repairing the internal combustion engine during operation may exceed the total cost of the engine by 5-6 times. Thus, there is a question of improving the system of technical service of engines of small tractors. This article considers the issue of increasing the efficiency of operation of internal combustion engines for small tractors, due to the effective conduct of after-sales or post-repair running-in and improving the maintenance system. Types of small-sized equipment are presented. The analysis of possible loading and speed modes of cold and hot running-in of internal combustion engines and means for their realization is carried out. Technical means for running-in and testing of internal combustion engines are analyzed. The following formulas are given for determination: smoke of exhaust gases at running-in of engines; light transmission of exhaust gases; speed control range; load torque; the content of harmful substances (Q) in the exhaust gases on the j-th components. The necessity of bench running-in of engines of small-sized agricultural machinery is substantiated. The functional scheme of the stand for running-in and testing of internal combustion engines is considered. The stages of cold and hot running-in of small-sized engines are described. With the help of the received information, the results are made and the analysis of methods of running-in of internal combustion engines of small-sized agricultural machinery is carried out.


Author(s):  
Mauro Francesco Sgroi

The concern related to global warming is generating a legislative pressure on reducing CO2 emissions that is forcing automotive industry to find alternative and more efficient solutions to internal combustion engines. In Europe, the current regulation for passenger vehicles limits the CO2 emissions calculated as fleet average to 130 g/km and fix a target value of 95 g/km to be achieved by 2021. Car manufacturers will have to pay heavy penalties for each registered vehicle exceeding the CO2 limits (€95 per exceeding gram by 2019). Concurrently, the regulations on toxic emissions (CO, NOx, unburned hydrocarbons, particulate matter) is also becoming more and more stringent and requires complex and costly abatement systems to respect the strict limitations imposed on NOx and particulate matter emissions. On the other hand, zero emission electric vehicles, based on batteries, are still not mature enough for a replacement of the internal combustion engine in extra-urban applications, since they are not able to guarantee the driving range required by customers. Hydrogen fuelled vehicles, could meet the same performance of conventional cars, but the cost of materials used in the fuel cell stack is preventing the penetration into the market. Therefore, even though characterized by low energy efficiency, the internal combustion engine will remain, in the short-medium term, the reference technology for the transport industry but the environmental regulations will impose its hybridization with electric systems. Hybrid architectures allow circulating in electric mode in urban areas, limiting the local pollution, and increase the efficiency of the car through energy recovery during breaking phases. An energetic analysis of conventional internal combustion engine reveals that about 70% percent of the chemical energy stored in the fuel is converted in to mechanical energy for traction: the remaining part is dissipated as heat in the exhaust gases (30%) and in the cooling circuit (40%). So a great amount of thermal energy (tens of kW) is available on a car and its effective recovery can dramatically increase the efficiency of the system. Hybrid systems facilitate this task, since the produced electric energy can be stored in the battery pack. Thermoelectric generators (TEGs) offer the possibility to directly convert thermal energy into electricity with a reduced complexity and potential low cost. Even though available semiconducting junctions are characterized by low efficiency and limited operating temperatures, coupling a TEG to the internal combustion engine would allow recovering about 1 kW of electric power on a medium size car, with a reduction of CO2 emissions of about 10 g/km.


2020 ◽  
Vol 67 (1) ◽  
pp. 104-110
Author(s):  
Aleksandr V. Gritsenko ◽  
Grigoriy N. Salimonenko ◽  
Maksim V. Nazarov

The introduction of methods for timely diagnostics of internal combustion engines allows maintaining the environmental indicators of the car fleet at the highest level. (Research purpose) The research purpose is in increasing the reliability of diagnostics of internal combustion engines by using data obtained by selective sampling of exhaust gases. (Materials and methods) Informational, mathematical and experimental research methods, including methods for statistical processing of results and analysis of data obtained during experiments were used during the study. (Results and discussion) The main systems that affect the environmental performance of internal combustion engines has been identified: the fuel supply system, the ignition system and the exhaust gas neutralization system. The article describes a generalized mathematical model for calculating the characteristics of exhaust gases. Authors conducted operational tests on 35 internal combustion engines with justification of their number according to standard methods. The actual value of diagnostic parameters was processed into relative percentages for drawing a nomogram. A zero value has been set for the reference state of the elements specified by the manufacturer. (Conclusions) It was found that the dominant number of failures accounted for internal combustion engines, in detail: the ignition system produces 15-25 percent of failures, the power system produces 30-44 percent, the exhaust system produces 10-15 percent. It was found that for unambiguous identification of any combination of factors, it is necessary to have output values of at least three evaluation criteria. It was found that the most sensitive parameters for evaluating the technical condition of the three systems are: changes in the engine crankshaft speed, the parameters of exhaust gas toxicity, CO, CO2, CH, O2 when providing test modes (operation of the internal combustion engine on 1 cylinder at 20 and 40 percent of the throttle opening). The article describes designed a gasoline engine loader for the implementation of diagnostic modes and control of diagnostic parameters, that allows to create operating loads with an accuracy of 0.1 percent.


2020 ◽  
Vol 221 ◽  
pp. 01002
Author(s):  
Yury Matveev ◽  
Marina Cherkasova ◽  
Viktor Rassokhin ◽  
Viktor Barskov ◽  
Victor Chernikov ◽  
...  

The article is devoted to the investigation and development of microsteam turbine unit of the LPI design for utilization of heat of exhaust gases of internal combustion engines. This installation will reduce the world carbon dioxide emissions, as well as add useful power for the needs of the consumer. Efficiency and environmental friendliness of the engine will increase. The article discusses development of the main directions of improvement of high-loaded steps of LPI, expansion of modern outlooks on the directions of MRI development and the use of LPI steps in the systems of heat recovery of exhaust gases of the internal combustion engine. The possibility to utilize the heat of exhaust gases of internal combustion engines by means of a turbine unit and the subsequent receipt of additional useful capacities are investigated in many developed countries of the world. Germany, Sweden, Japan, PRC and other leading countries in the automotive industry are intensively conducting works in this direction. The results of such studies have already found application in some freight cars. In the Russian market, this type of turbine is spread very weakly. Turbine unit behind the internal combustion engine works in conditions of low volumetric consumption of the working fluid, which leads to a decrease in the heights of the flow parts of the guides and working grids, because of which the relative gaps in the seals increase. This leads to the growth of leakage of the working fluid. On the other hand, a high degree of pressure reduction when choosing single-stage turbines leads to supersonic


2019 ◽  
Vol 178 (3) ◽  
pp. 182-186
Author(s):  
Zbigniew SROKA ◽  
Maciej DWORACZYŃSKI

The modification of the downsizing trend of internal combustion engines towards rightsizing is a new challenge for constructors. The change in the displacement volume of internal combustion engines accompanying the rightsizing idea may in fact mean a reduction or increase of the defining swept volume change factors and thus may affect the change in the operating characteristics as a result of changes in combustion process parameters - a research problem described in this publication. Incidents of changes in the displacement volume were considered along with the change of the compression space and at the change of the geometric degree of compression. The new form of the mathematical dependence describing the efficiency of the thermodynamic cycle makes it possible to evaluate the opera-tion indicators of the internal combustion engine along with the implementation of the rightsizing idea. The work demonstrated the in-variance of cycle efficiency with different forms of rightsizing.


2021 ◽  
Vol 4 (30) ◽  
pp. 99-105
Author(s):  
A. V. Summanen ◽  
◽  
S. V. Ugolkov ◽  

This article discusses the issues of assessing the technical condition of the camshaft, internal combustion engine. The necessary parameters for assessing the technical condition of the engine camshaft have been determined. How and how to measure and calculate this or that parameter is presented in detail. Methods for calculating the parameters are presented. A scheme and method for measuring neck wear, determining the height of the cam, determining the beating of the central journal of the camshaft are proposed. The main defects of the camshafts are presented. The issues of the influence of these parameters on the operability of the camshaft and the internal combustion engine as a whole are considered.


2021 ◽  
pp. 13-20
Author(s):  

The prospects of using the gas-static suspension of the internal combustion engine piston in transport vehicles and power plants are considered. The diagram of the piston and the method for calculating the stiffness and bearing capacity of the gas layer surrounding the piston are presented, as well as the results of experiments that showed the relevance of this method. The possibility of gas and static centering of the engine piston is confirmed. Keywords: internal combustion engine, piston, gasstatic suspension, stiffness, bearing capacity, gas medium. [email protected]


2019 ◽  
pp. 146808741989358 ◽  
Author(s):  
Mostafa A ElBahloul ◽  
ELsayed S Aziz ◽  
Constantin Chassapis

Fuel conversion efficiency is one of the main concerns in the field of internal combustion engine systems. Although the Otto cycle delivers the maximum efficiency possible in theory, the kinematics of the slider–crank mechanism of the conventional internal combustion engines makes it difficult to reach this level of efficiency in practice. This study proposes using the unique hypocycloid gear mechanism instead of the conventional slider–crank mechanism for the internal combustion engines to increase engine efficiency and minimize frictional power losses. The hypocycloid gear mechanism engine’s kinematics provides the means for the piston-rod assembly to reciprocate in a straight-line motion along the cylinder axis besides achieving a nonlinear rate of piston movement. As a result, this characteristic allows for a true constant-volume combustion, which in turn would lead to higher work output. An in-cylinder gas volume change model of the hypocycloid gear mechanism engine was developed and incorporated into the thermodynamic model for the internal combustion engine cycle. The thermodynamic model of the hypocycloid gear mechanism engine was developed and simulated using MATLAB/Simulink software. A comparison between the conventional engine and the hypocycloid gear mechanism engine in terms of engine performance characteristics showed the enhancements achieved using hypocycloid gear mechanism for internal combustion engine applications. The hypocycloid gear mechanism engine analysis results indicated higher engine efficiency approaching that of the Otto cycle.


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