scholarly journals Improving the Uncertainty of Exhaust Gas Temperature Measurements in Internal Combustion Engines

2020 ◽  
Vol 142 (7) ◽  
Author(s):  
Nick Papaioannou ◽  
Felix Leach ◽  
Martin Davy
Keyword(s):  
Measurement Errors ◽  
Internal Combustion Engines ◽  
Internal Combustion ◽  
Operating Conditions ◽  
Exhaust Gas ◽  
Combustion Engines ◽  
Gas Temperature ◽  
Crank Angle ◽  
Reconstructed Temperature ◽  
Exhaust Gas Temperature

Abstract Accurate measurement of exhaust gas temperature (EGT) in internal combustion engines (ICEs) is a challenging task. The most common, and also the most practical, method of measurement is to insert a physical probe, for example, a thermocouple or platinum resistance thermometer, directly into the exhaust flow. Historically, consideration of the measurement errors induced by this arrangement has focused on the effects of radiation and the loss of temporal resolution naturally associated with a probe of finite thermal inertia operating within a pulsating flow with a time-varying heat input. However, a recent numerical and experimental study has shown that conduction errors may also have a significant effect on the measured EGT, with errors approaching ∼80 K depending on engine operating conditions. In this work, the authors introduce a new temperature compensation method that can correct for the combined radiation, conduction, and dynamic response errors introduced during the measurement and thereby reconstruct the “true” crank-angle resolved EGT to an estimated accuracy of ±1.5%. The significance of this result is demonstrated by consideration of a first law energy balance on an engine. It is shown that the exhaust gas enthalpy term is underestimated by 15–18% when calculated using conventional time-averaged data as opposed to using the mass-average exhaust enthalpy that is obtained by combining the reconstructed temperature data with crank angle-resolved exhaust flow rates predicted by a well-validated one-dimensional (1D) simulation.

scholarly journals Exhaust Gas Temperature Measurements in Diagnostics of Turbocharged Marine Internal Combustion Engines Part I Standard Measurements

2015 ◽  
Vol 22 (1) ◽  
pp. 47-54 ◽  
Author(s):  
Zbigniew Korczewski
Keyword(s):  
Internal Combustion Engines ◽  
Internal Combustion ◽  
Technical Condition ◽  
Temperature Measurements ◽  
Injection System ◽  
Exhaust Gas ◽  
Combustion Engines ◽  
Gas Temperature ◽  
Measuring Signal ◽  
Exhaust Gas Temperature

Abstract The article discusses the problem of diagnostic informativeness of exhaust gas temperature measurements in turbocharged marine internal combustion engines. Theoretical principles of the process of exhaust gas flow in turbocharger inlet channels are analysed in its dynamic and energetic aspects. Diagnostic parameters are defined which enable to formulate general evaluation of technical condition of the engine based on standard online measurements of the exhaust gas temperature. A proposal is made to extend the parametric methods of diagnosing workspaces in turbocharged marine engines by analysing time-histories of enthalpy changes of the exhaust gas flowing to the turbocompressor turbine. Such a time-history can be worked out based on dynamic measurements of the exhaust gas temperature, performed using a specially designed sheathed thermocouple. The first part of the article discusses possibilities to perform diagnostic inference about technical condition of a marine engine with pulse turbocharging system based on standard measurements of exhaust gas temperature in characteristic control cross-sections of its thermal and flow system. Selected metrological issues of online exhaust gas temperature measurements in those engines are discusses in detail, with special attention being focused on the observed disturbances and thermodynamic interpretation of the recorded measuring signal. Diagnostic informativeness of the exhaust gas temperature measurements performed in steady-state conditions of engine operation is analysed in the context of possible evaluations of technical condition of the engine workspaces, the injection system, and the fuel delivery process.

Misfire detection on internal combustion engines using exhaust gas temperature with low sampling rate

2011 ◽  
Vol 31 (17-18) ◽  
pp. 4125-4131 ◽  
Author(s):  
Masayuki Tamura ◽  
Hitoshi Saito ◽  
Yukimaro Murata ◽  
Kunihiro Kokubu ◽  
Satoshi Morimoto
Keyword(s):  
Internal Combustion Engines ◽  
Sampling Rate ◽  
Internal Combustion ◽  
Exhaust Gas ◽  
Combustion Engines ◽  
Gas Temperature ◽  
Exhaust Gas Temperature ◽  
Misfire Detection

Numerical Modelling of Internal Combustion Engines Fuelled by Hydrogen-Natural Gas Blends

2008 ◽  
Author(s):  
Antonio Mariani ◽  
Biagio Morrone ◽  
Andrea Unich
Keyword(s):  
Natural Gas ◽  
Internal Combustion Engines ◽  
Exhaust Gas Recirculation ◽  
Internal Combustion ◽  
Flame Speed ◽  
Operating Conditions ◽  
Nox Emissions ◽  
Exhaust Gas ◽  
Combustion Engines ◽  
Gas Recirculation

The strict rules that European Community has given for reducing vehicle emissions require new views on the choice of combustion engines and fuels. In fact, the rules will probably introduce in the near future limitations on carbon dioxide (CO2) emissions. Internal combustion engines are responsible for emission of unburned hydrocarbons (HC), nitrogen oxides (NOx) and particulate matter (PM). The aim of the present paper is the study of the effects of hydrogen-natural gas blends (HCNG) on the performance, efficiency and NOx emissions of internal combustion engines (ICE). A numerical engine model has been developed to display how the presence of hydrogen in such mixtures impacts on flame speed and burn rates. The model allows the comparison of different fuels, in terms of engine brake efficiency and pollutant emissions. An important variable for the combustion process is the ignition timing which is set employing Maximum Brake Torque (MBT) spark advance. Engine operating conditions considered in the numerical analysis have been obtained by imposing engine speed and load. Brake power, efficiency and NOx emissions are calculated for the most frequent operating conditions met by automotive engines, i.e. part load and low speed. The effect of natural gas (NG) enrichment by hydrogen on flame speed has been considered. Thus, faster combustion and the reduction of energy content in the air-fuel mixtures due to the lower density of hydrogen are taken into account. Hydrogen enrichment of natural gas improves combustion stability in critical conditions, allowing the use of extremely lean mixtures or high Exhaust Gas Recirculation rates. The results show that by employing an MBT spark advance, the HCNG blends furnish improvements of engine brake efficiency compared with compressed natural gas (CNG), which are more relevant at part loads and for the higher hydrogen content. Anyway, higher NOx emissions are observed due to the increased temperatures into the cylinders. Thus, the analysis also takes into account the Exhaust Gas Recirculation (EGR) dilution technique to reduce the NOx emissions. A large reduction of such pollutant, which has been estimated greater than 50%, can be achieved by using a 10% EGR. Furthermore higher engine efficiency is obtained using EGR due to reduced pumping work, reduced heat loss to the walls because of lower gas temperature and a reduction in the degree of dissociation in the high temperature burned gases.

scholarly journals The influence of centrial forces on crankshaft bearing lubrication is in emergency modes of the engine of the car

2021 ◽  
Vol 12 (2) ◽  
pp. 112-121
Author(s):  
Oleksandr Khrulev ◽  
◽  
Olexii Saraiev ◽  
Iryna Saraieva ◽  
◽  
...  
Keyword(s):  
Internal Combustion Engines ◽  
Operating Mode ◽  
Internal Combustion ◽  
Technical Condition ◽  
Operating Conditions ◽  
Combustion Engines ◽  
Connecting Rod ◽  
Oil Supply ◽  
Technical Expert ◽  
The Difference

The analysis of the crankshaft bearing condition of the automotive internal combustion engines in the case of insufficiency and breakage of oil supply to them is carried out. It is noted that this fault is one of the most common causes of damage to rubbing pairs in operation. At the same time, the different groups of bearings are often damaged, which cannot be explained within the framework of existing models of plain bearing lubrication. The objective of the work is to develop a mathematical model of oil supply to connecting rod bearings in emergency mode, taking into account the characteristic features of the bearing design. The model also, depending on the nature of the damage, should help to determine and explain the causes of bearing failures if they occur in different modes when operating conditions are broken. A computational model has been developed that makes it possible to assess the effect of design differences in the features of oil supply and the action of the centrifugal forces during crankshaft rotation on the oil column in the lubrication hole where oil is supplied to the conrod bearing. Calculations of the change in time of the oil supply pressure to the connecting rod bearings for the various designs of the crankshaft lubrication holes have been performed. It is shown that, depending on the operating mode of the engine and its design, the oil pressure in front of the connecting rod bearings does not disappear immediately after oil supply failure to crankshaft. Moreover, the lower the crankshaft speed is, the longer the lubrication of the conrod bearings will continue. The calculation results are confirmed by the data of the expert studies of the engine technical condition, in which the crankshaft was wedged in the damaged main bearings was found in the absence of serious damage to the connecting rod ones. It has been found that such features of the damage correspond to an rapid breakage of the oil supply to the crankshaft in the case of such operational damage as the oil pump and pressure reducing valve failure, the oil filter seal and oil pan destruction, etc. The developed model explains the difference in lubrication conditions and in the damage feature to the main and connecting rod bearings in the emergency cases of the oil supply breakage, which are observed during operation, and helps to clarify the failure causes. This makes it possible to use the model and the obtained data when providing auto technical expert studies of the failure causes of automobile internal combustion engines This makes it possible to use the model and the obtained data when providing auto technical expert studies of the failure causes of automobile internal combustion engines when the operating conditions are broken.

Effect of Fuel Injection Strategy on DPF Regeneration in Single Cylinder Diesel Engine

2015 ◽  
Author(s):  
Sungjun Yoon ◽  
Hongsuk Kim ◽  
Daesik Kim ◽  
Sungwook Park
Keyword(s):  
Diesel Engine ◽  
Fuel Injection ◽  
Operating Conditions ◽  
Experimental Results ◽  
Exhaust Gas ◽  
Post Injection ◽  
Gas Temperature ◽  
Injection Strategy ◽  
Dpf Regeneration ◽  
Exhaust Gas Temperature

Stringent emission regulations (e.g., Euro-6) force automotive manufacturers to equip DPF (diesel particulate filter) on diesel cars. Generally, post injection is used as a method to regenerate DPF. However, it is known that post injection deteriorates specific fuel consumption and causes oil dilution for some operating conditions. Thus, an injection strategy for regeneration becomes one of key technologies for diesel powertrain equipped with a DPF. This paper presents correlations between fuel injection strategy and exhaust gas temperature for DPF regeneration. Experimental apparatus consists of a single cylinder diesel engine, a DC dynamometer, an emission test bench, and an engine control system. In the present study, post injection timing covers from 40 deg aTDC to 110 deg aTDC and double post injection was considered. In addition, effects of injection pressures were investigated. The engine load was varied from low-load to mid-load and fuel amount of post injection was increased up to 10mg/stk. Oil dilution during fuel injection and combustion processes were estimated by diesel loss measured by comparing two global equivalences ratios; one is measured from Lambda sensor installed at exhaust port, the other one is estimated from intake air mass and injected fuel mass. In the present study, the differences in global equivalence ratios were mainly caused from oil dilution during post injection. The experimental results of the present study suggest an optimal engine operating conditions including fuel injection strategy to get appropriate exhaust gas temperature for DPF regeneration. Experimental results of exhaust gas temperature distributions for various engine operating conditions were summarized. In addition, it was revealed that amounts of oil dilution were reduced by splitting post injection (i.e., double post injection). Effects of injection pressure on exhaust gas temperature were dependent on combustion phasing and injection strategies.

scholarly journals The use of thermography in the diagnosis of ship piston internal combustion engines

2018 ◽  
Vol 182 ◽  
pp. 01027
Author(s):  
Jan Monieta
Keyword(s):  
Infrared Thermography ◽  
Internal Combustion Engines ◽  
Experimental Studies ◽  
Internal Combustion ◽  
Technical Condition ◽  
Operating Conditions ◽  
Combustion Engines ◽  
Destructive Testing ◽  
Fault State ◽  
Floating Objects

The intensity of infrared radiation emitted by objects depends mainly on their temperature. One of the diagnostic signals may be the temperature field. In infrared thermography, this quantity is used as an indicator of the technical condition of marine objects. The article presents an overview of the use of infrared thermography for the diagnosis mainly of marine piston floating objects and various types of reciprocating internal combustion engines as well as examples of own research results. A general introduction to infrared thermography and common procedures for temperature measurement and non-destructive testing are presented. Experimental research was carried out both in laboratory conditions and in the operating conditions of sea-going vessels. Experimental studies consisted of the presentation of photographs of the same objects made in visible light and the use of infrared thermography. The same objects were also compared, but for different cylinders of the tested internal combustion engines as well as for the up state and fault state. The characteristics of the temperature values at selected points were taken depending on the engine load along with the approximation mathematical models of these dependencies.

Sign in / Sign up

Export Citation Format

Share Document