The Simulation Calculation of Temperatures on Valve Seats of Combustion Engine and its Verification

2014 ◽  
Vol 1016 ◽  
pp. 577-581 ◽  
Author(s):  
Pavel Brabec ◽  
Aleš Dittrich
Keyword(s):  
Cylinder Head ◽  
Combustion Engine ◽  
Combustion Process ◽  
Exhaust Valve ◽  
Gas Temperature ◽  
Si Engine ◽  
Simulation Calculation ◽  
Exhaust Gas Temperature ◽  
Cooling And Lubrication ◽  
Complex Parts

The paper deals with the load of the head of the engine. Head of SI engine, which has molded seat of intake and exhaust valve, is one of the most complex parts of the engine. It contains intake and exhaust ports, spark plugs, timing of the mechanism and channels for cooling and lubrication. Much of the final form of this component also contributes its load, which is both heat and mechanical. The biggest influence on the deformation of embedded saddles exhaust valve has a temperature distribution in the cylinder head. These temperatures are influenced by many factors, especially temperature and coolant flow, load and engine speed, which affect the combustion process and exhaust gas temperature (the engine mode is constantly changing, therefore the thermal load on the valve seats is different). In our paper we will only deal with the heat load of the cylinder head of the engine. Currently, the most common use of appropriate software tools for determining the distribution as voltage or temperature. The simulation results may not always be identical to the actual situation, so it is necessary to perform by verification. The paper described measurements of temperature on the inserted valve seats cylinder head of the engine.

Use of Early Exhaust Valve Opening to Improve Combustion Efficiency and Catalyst Effectiveness in a Multi-Cylinder RCCI Engine System: A Simulation Study

2014 ◽  
Author(s):  
Anand Nageswaran Bharath ◽  
Nitya Kalva ◽  
Rolf D. Reitz ◽  
Christopher J. Rutland
Keyword(s):  
System Simulation ◽  
Combustion Efficiency ◽  
Exhaust Valve ◽  
Exhaust Gas ◽  
Gas Temperature ◽  
Flow Rates ◽  
Low Load ◽  
Valve Opening ◽  
Engine System ◽  
Exhaust Gas Temperature

Low Temperature Combustion (LTC) strategies such as Reactivity Controlled Compression Ignition (RCCI) can result in significant improvements of fuel economy and emissions reduction. However, they can produce significant carbon monoxide and unburnt hydrocarbon emissions at low load operating conditions due to poor combustion efficiencies at these operating points, which is a consequence of the low combustion temperatures that cause the oxidation rates of these species to slow down. The exhaust gas temperature is also not high enough at low loads for effective performance of turbocharger systems and diesel oxidation catalysts (DOC). The DOC is extremely sensitive to exhaust gas temperature changes and lights off only when a certain temperature is reached, depending on the catalyst specifications. Uncooled EGR can increase combustion temperatures, thereby improving combustion efficiency, but high EGR concentrations of 50% or more are required, thereby increasing pumping work and reducing volumetric efficiency. However, with early exhaust valve opening, the exhaust gas temperature can be much higher, allowing lower EGR flow rates, and enabling activation of the DOC for more effective oxidization of unburnt hydrocarbons and CO in the exhaust. In this paper, a multi-cylinder engine system simulation of RCCI at low load operation with early exhaust valve opening is presented, along with consideration of the exhaust aftertreatment system. The combustion process is modeled using the 3D CFD code, KIVA, and the heat release rates obtained from this combustion are used in a GT-Power model of a turbocharged, multi-cylinder light-duty RCCI engine for a full system simulation. The post-turbine exhaust gas is fed into GT-Power’s aftertreatment model of the engine’s DOC to determine the catalyst response. It is confirmed that opening the exhaust valve earlier increases the exhaust gas temperature, and hence lower EGR flow rates are needed to improve combustion efficiency. It was also found that exhaust temperatures of around 457 K are required to light off the catalyst and oxidize the unburnt hydrocarbons and CO effectively. Performance of the DOC was drastically improved and higher amounts of unburnt hydrocarbons were oxidized by increasing the exhaust gas temperature.

Rapid Prototyping for Optimization of the Charge Motion in Internal Combustion Engines Driven by Sewage Gas

2019 ◽  
Vol 141 (12) ◽  
Author(s):  
Lucas Konstantinoff ◽  
Thomas Steiner ◽  
Dominik Mairegger ◽  
Guenther Herdin ◽  
Martin Pillei ◽  
...  
Keyword(s):  
Rapid Prototyping ◽  
Cylinder Head ◽  
Internal Combustion Engines ◽  
Test Bench ◽  
Positive Impact ◽  
Combustion Engine ◽  
Combustion Process ◽  
Charge Motion ◽  
Lean Combustion ◽  
Static Flow

Abstract This paper presents a newly developed method using rapid prototyping (RP) to develop gas engine cylinder heads with optimized charge motion characteristics to adapt to lean-burn and Miller combustion process requirements. The geometry in close vicinity to the inlet valve seats was designed to increase swirl and flow performance of the cylinder heads. A three-dimensional (3D) printer was used to realize a rapid prototyping concept for the testing of multiple designs; the effects of the different designs were measured using a static flow test bench and a laser-optical method to visualize the flow patterns. The results of the static flow bench tests showed potentially higher flow and swirl performance, with one high-swirl version proving beneficial specifically for lean-combustion and one high-flow version matching the Miller combustion requirements. The two cylinder head versions were then manufactured and the lean-combustion version was tested for on-engine performance on a 150 kW sewage-gas driven lean-combustion engine. It has been shown that the cylinder head generates higher swirl on the test bench but achieves only a slight increase in combustion speed on the test engine. The potential to increase engine efficiency by intensifying swirl is, therefore, considered exploitable. Research has further shown the coefficient of variance (CoV) was reduced by 0.3–1.2%. Charge exchange losses have also been demonstrated to decrease at all tested engine settings. It has further been found that higher swirl intensity has a positive impact on engine emission levels, as the engine out carbon monoxide (CO) emission can be reduced by approximately 70 mg·m−3.

scholarly journals Potential of hydrogen addition to natural gas or ammonia as a solution towards low- or zero-carbon fuel for the supply of a small turbocharged SI engine

2021 ◽  
Vol 312 ◽  
pp. 07022
Author(s):  
Alfredo Lanotte ◽  
Vincenzo De Bellis ◽  
Enrica Malfi
Keyword(s):  
Alternative Fuels ◽  
Laminar Flame ◽  
Combustion Engine ◽  
Numerical Study ◽  
Combustion Process ◽  
Pollutant Emissions ◽  
Si Engine ◽  
Hydrogen Addition ◽  
Emission Regulations ◽  
Zero Carbon

Nowadays there is an increasing interest in carbon-free fuels such as ammonia and hydrogen. Those fuels, on one hand, allow to drastically reduce CO2 emissions, helping to comply with the increasingly stringent emission regulations, and, on the other hand, could lead to possible advantages in performances if blended with conventional fuels. In this regard, this work focuses on the 1D numerical study of an internal combustion engine supplied with different fuels: pure gasoline, and blends of methane-hydrogen and ammonia-hydrogen. The analyses are carried out with reference to a downsized turbocharged two-cylinder engine working in an operating point representative of engine operations along WLTC, namely 1800 rpm and 9.4 bar of BMEP. To evaluate the potential of methane-hydrogen and ammonia-hydrogen blends, a parametric study is performed. The varied parameters are air/fuel proportions (from 1 up to 2) and the hydrogen fraction over the total fuel. Hydrogen volume percentages up to 60% are considered both in the case of methane-hydrogen and ammonia-hydrogen blends. Model predictive capabilities are enhanced through a refined treatment of the laminar flame speed and chemistry of the end gas to improve the description of the combustion process and knock phenomenon, respectively. After the model validation under pure gasoline supply, numerical analyses allowed to estimate the benefits and drawbacks of considered alternative fuels in terms of efficiency, carbon monoxide, and pollutant emissions.

Simulation Research on the Application of Thermoelectric Waste Heat Recovery of Internal Combustion Engine

2010 ◽  
Author(s):  
Maohai Wang ◽  
Thomas Josef Daun ◽  
Yangjun Zhang ◽  
Weilin Zhuge
Keyword(s):  
Internal Combustion Engine ◽  
Waste Heat ◽  
Combustion Engine ◽  
Internal Combustion ◽  
Parameter Study ◽  
Exhaust Gas ◽  
Gas Temperature ◽  
Simulation Research ◽  
Exhaust Gas Temperature ◽  
Engine Power

In this paper, the development of a thermoelectric generator (TEG) simulation model and its implementation into an internal combustion engine (ICE) system model are demonstrated. The TEG model is calibrated with respect to an experimental basis presented in a previously published paper. A TEG parameter study, an analysis of the overall system and the interaction between the TEG and the ICE are carried out. The simulation results indicate that the exhaust gas temperature has a much more significant influence on the TEG performance than the exhaust gas mass flow rate. Without considering the influence of additional backpressure, the application of a TEG shows potential to increase the effective engine power; thereby improving the overall efficiency by approximately 0.6 to 1.7% (depending on engine speed and load). However, when taking additional backpressure into account, this gain in effective engine power is reduced slightly, resulting in a change of the efficiency range to between 0.2 and 1.7%. This illustrates the importance of taking the backpressure into account when designing a real world TEG.

Experimental and Numerical Investigations in a Gas-Fired Boiler With Combustion Stabilizing Device

2019 ◽  
Vol 141 (11) ◽  
Author(s):  
Zhengming Yi ◽  
Zheng Zhou ◽  
Qian Tao ◽  
Zhiwei Jiang
Keyword(s):  
Heat Exchange ◽  
Combustion Process ◽  
Side Surface ◽  
Coke Oven ◽  
Combustion Stability ◽  
Nox Emissions ◽  
Gas Temperature ◽  
Safety And Reliability ◽  
Set Up ◽  
Exhaust Gas Temperature

The combustion stability has a significant influence on safety and reliability of a gas-fired boiler. In this study, a numerical model was first established and validated to investigate the effect of combustion stabilizing device on flow and combustion characteristics of 75 t/h blast furnace gas (BFG) and coke oven gas (COG) mixed-fired boiler. The results indicated that the device coupled with four corner burners enables the flame to spin upward around its side surface, which facilitates heat exchange between BFG and the device. Under stable combustion condition, the combustion stabilizing device can be used as a stable heat source and enhance heat exchange in the furnace. Then, to obtain optimal COG ratio, combustion process of different blending ratios were experimentally investigated. The experimental results revealed that the energy loss due to high exhaust gas temperature is relatively high. COG ratio should be set up taking into account both boiler efficiency and NOX emissions. When COG blending ratio is maintained about 20%, the thermal efficiency of the boiler is 88.84% and the NOX concentration is 152 mg/m3 at 6% O2, meeting NOX emissions standard for the gas boiler.

scholarly journals Engine Performance Analysis by Studying Heat Transfer in the Valve Seat through Steady-State Thermal Simulation

2021 ◽  
Vol 2129 (1) ◽  
pp. 012097
Author(s):  
M A S M Hassan ◽  
A B Shahriman ◽  
Z M Razlan ◽  
N S Kamarrudin ◽  
W K N Khairunizam ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Steady State ◽  
High Speed ◽  
Thermal Loading ◽  
Combustion Engine ◽  
Combustion Process ◽  
Optimal Operation ◽  
Exhaust Valve ◽  
Valve Seat

Abstract As the engine reached high speed, the exhaust valve temperature increased exponentially due to the exhaust gas produced by the combustion process between the mixture of air and fuel within the combustion chamber of the internal combustion engine. The valve is subjected to thermal loading due to high temperature and pressure within the cylinder, which must withstand a material temperature for sustainable and optimal operation. To avoid this loss, a perfect medium must be prepared to ensure that the heat is extracted smoothly. This can be done when the valve is in contact with the seat and there is a periodic heat transfer contact. Therefore, it is imperative to research the correlation between valve and valve seat to understand the two sections’ heat transfer mechanism. In this study, thermal contact analysis was used to identify heat transfer between the valve and the valve seat as both parts are interconnected. This research also has an interest in studying the two surface conduction mechanisms as the exhaust valve closed in steady-state conditions. Thus, this study portrays a significant method, particularly for the determining the distribution of temperature, heat flux, and heat flux direction between the valve and its seat using ANSYS Workbench.

scholarly journals Experimental study of carbide as an alternative fuel using in Internal Combustion Engine

2019 ◽  
pp. 106-114
Author(s):  
Ganesh M ◽  
Jagadeesan S ◽  
Bharathwaj S
Keyword(s):  
Internal Combustion Engine ◽  
Combustion Engine ◽  
Internal Combustion ◽  
Alternative Fuel ◽  
Exhaust Gas ◽  
Gas Temperature ◽  
Smoke Emission ◽  
Brake Thermal Efficiency ◽  
Hydrocarbon Emission ◽  
Exhaust Gas Temperature

The emerging world need alternative fuel for diesel and petrol. This is the experiment that using the carbide as the alternative fuel for internal combustion engine by converting the carbide as the acetylene using water. The brake thermal efficiency, exhaust gas temperature, smoke emission, CO2 emission, NOx emission, hydrocarbon emission, performance of the engine is studied under this Experiment

Combustion Characteristics of HCCI in Motorcycle Engine

2009 ◽  
Author(s):  
Yuh-Yih Wu ◽  
Bo-Liang Chen
Keyword(s):  
Cylinder Head ◽  
Peak Pressure ◽  
Combustion Engine ◽  
Pressure Rise ◽  
Combustion Characteristics ◽  
Gas Temperature ◽  
Hcci Combustion ◽  
Excess Air ◽  
Intake Air Heating ◽  
Motorcycle Engine

Homogeneous charge compression ignition (HCCI) is recognized as an advanced combustion system of internal combustion engine for reducing fuel consumption and exhaust emissions. This paper studied a 150 cc air-cooled four-stroke motorcycle engine operating HCCI combustion. The compression ratio was increased from 10.5 to 12.4 by modifying the cylinder head. The kerosene fuel was used without intake air heating and operated at various excess air ratios (λ), engine speeds, and EGR rates. The combustion characteristics and emissions on the target engine were measured. It was found that keeping the cylinder head temperature at around 120–130°C is important for stable experiment. Two-stage ignition was observed from the heat release rate curve, which was calculated from the cylinder pressure. Higher first stage ignition temperature causes higher peak cylinder gas temperature. Higher λ or EGR causes lower peak pressure, lower maximum rate of pressure rise (MRPR), and higher emission CO. However, EGR is better than excess air for decreasing the peak pressure and MRPR without deteriorating the engine output.

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