scholarly journals The influence of non-cooled exhaust gas recirculation on the diesel engine parameters

2017 ◽  
Vol 171 (4) ◽  
pp. 269-273
Author(s):  
Jerzy CISEK
Keyword(s):  
Diesel Engine ◽  
Control Unit ◽  
Energy Performance ◽  
Intake Manifold ◽  
Total Efficiency ◽  
Exhaust Gas ◽  
Engine Torque ◽  
Exhaust Gases ◽  
Start Of Injection ◽  
Gas Recirculation

This paper presents the results of the diesel engine research on the energy performance, components of exhaust gases and smoke and parameters related to the supply system for VW 1.9 TDI working in 2 modes: with standard, non-cooled EGR system, and without this system. All of measurements were carried out on the some engine speed – 2000 rpm (speed of maximum engine torque) and various engine loads. It was found that the serial engine control unit switches the EGR system off above 150 Nm engine load (Momax = 295 Nm). In this range of load the engine running with EGR is characterized by higher fuel consumption (lower total efficiency) ca. 5%, compared with engine without EGR. Concentration of NOx in exhaust gases was lower up to 45% but, at the same time, exhaust gas smoke and concentration of carbon oxides were strongly increasing. It can be seen that EGR system increases the temperature (up to 110oC) and changes the composition of air-exhaust gas in the intake manifold. One of reason of this fact is self-changing start of injection. Additional effect of EGR is lower air pressure behind turbocharger, because the flow of exhaust gases (into EGR) is taken before the

scholarly journals The influence of non-cooled exhaust gas recirculation on the indicator diagrams and heat release parameters in diesel engine cylinder

2017 ◽  
Vol 171 (4) ◽  
pp. 283-288
Author(s):  
Jerzy CISEK
Keyword(s):  
Diesel Engine ◽  
Heat Release ◽  
Exhaust Gas Recirculation ◽  
Exhaust Gas ◽  
Engine Torque ◽  
Exhaust Gases ◽  
Measurement Systems ◽  
Start Of Injection ◽  
Rate Of Heat Release ◽  
Gas Recirculation

This paper presents the results of the diesel engine research on the indicator and heat realized diagrams for VW 1.9 TDI working in 2 modes: with standard, non-cooled EGR system, and without this system. All of measurement was carried out on the some engine speed – 2000 rpm (speed of maximum engine torque) and various engine load. Some of the analyzed parameters were read directly from the measurement systems (e.g. indicator diagrams) or engine controller (e.g. start of injection) and the rest of them had to be calculated. The calculation of rate of heat release (dQ/dα) was based on the well-known mathematical model. When the exhaust gas recirculation valve is open, the maximum of combustion pressure and rate of maximum kinetic heat release (dQk/dα)max are smaller than when the valve is closed. These facts are connected with the shorter self-combustion delay for engine working with EGR. But this is also associated with reduction of the rate of maximum diffusion heat release (dQd/dα)max, which means that more particulates (PM) are excreted into the atmosphere. This fact explains e.g. significantly higher smog of exhaust gases for diesel engine which works with EGR system. The analysis results show that exhaust gas recirculation system slightly deteriorates the energetic parameters of VW 1.9 TDI engine, but, at the same time, significantly reduces the level of toxic nitrogen oxides in exhaust gases

An experimental investigation on performance, emissions, and combustion in a manifold injection for different exhaust gas recirculation flowrates in hydrogen—diesel dual-fuel operations

2008 ◽  
Vol 222 (11) ◽  
pp. 2131-2145 ◽  
Author(s):  
N Saravanan ◽  
G Nagarajan
Keyword(s):  
Experimental Investigation ◽  
Exhaust Gas Recirculation ◽  
Intake Manifold ◽  
Dual Fuel ◽  
Injection Timing ◽  
Exhaust Gas ◽  
Exhaust Gases ◽  
Injection Duration ◽  
Performance And Emissions ◽  
Gas Recirculation

Hydrogen is receiving considerable attention as an alternative fuel to replace the rapidly depleting petroleum-based fuels. Its clean burning characteristics help to meet the stringent emission norms. In this experimental investigation a single-cylinder diesel engine was converted to operate in hydrogen—diesel dual-fuel mode. Hydrogen was injected in the intake manifold and the diesel was injected directly inside the cylinder. The injection timing and the injection duration of hydrogen were optimized on the basis of performance and emissions. Best results were obtained with hydrogen injection at gas exchange top dead centre with an injection duration of 30° crank angle. The flowrate of hydrogen was optimized as 7.5l/min with optimized injection timing and duration. The optimized exhaust gas recirculation (EGR) flowrate was 20 per cent at 75 per cent load. The optimized timings were chosen on the basis of performance, emission, and combustion characteristics. The EGR technique was adopted in the hydrogen—diesel dual-fuel mode by varying the EGR flowrate from 0 per cent to 25 per cent in steps of 5 per cent. The maximum quantity of exhaust gases recycled during the test was 25 per cent (up to 75 per cent load); beyond that unstable combustion was observed with an increase in smoke. The brake thermal efficiency with 20 per cent EGR decreases by 9 per cent compared with diesel. The nitrogen oxide (NO x) emission in hydrogen manifold injection decreases by threefold with 20 per cent EGR operation at full load. The NO x emission tends to reduce drastically with increase in the EGR percentage at all load conditions owing to the increase in heat capacity of the exhaust gases. The smoke decreases by 80 per cent in the dual-fuel operation compared with diesel at 75 per cent load.

scholarly journals Calculation studies of the influence of exhaust gas recirculation on the characteristics of the natural gas-fueled diesel engine

2021 ◽  
Vol 2061 (1) ◽  
pp. 012065
Author(s):  
I I Libkind ◽  
A V Gonturev
Keyword(s):  
Diesel Engine ◽  
Natural Gas ◽  
Fuel Mixture ◽  
Exhaust Gas Recirculation ◽  
Intake Manifold ◽  
Nox Emissions ◽  
Exhaust Gas ◽  
Diesel Cycle ◽  
Gas Fueled ◽  
Gas Recirculation

Abstract When converting diesel engines to run on natural gas on the gas-diesel cycle, additional problems arise associated with the high thermal stress of the exhaust valves and valve seats at high loads and engine speeds. There is also an increase in NOx emissions due to higher combustion temperatures of natural gas. One of the ways to improve the economic and environmental performance of engines operating on a gas-diesel cycle with a lean air-fuel mixture is to optimize the combustion of the air-fuel mixture by using an exhaust gas recirculation system (EGR). The principle of operation of this system is as follows: exhaust gas entering the intake manifold and further into the combustion chamber reduces the oxygen concentration in the air-fuel mixture, which leads to a dilution effect and, accordingly, to a decrease in combustion temperature and a decrease in NOx content. In order to study the influence of EGR on the dual-fuel gas and diesel engine parameters in the AVL Boost software package, a computer model of the existing 6ChN13/15 engine was developed. A low-pressure EGR system with an exhaust gas cooler was simulated on this engine. Values of NOx emissions, brake specific fuel consumption (BSFC) and brake efficiency have been obtained at different recirculation rate by calculation method. These values allow to estimate the feasibility of using a cooled EGR in a natural gas-fueled diesel engine.

Evaluation of the Integral toxicity of Exhaust Gases of a Diesel Engine Operating on Natural Gas and Alcohol Emulsions

2019 ◽  
Vol 23 (9) ◽  
pp. 60-65 ◽  
Author(s):  
V.A. Likhanov ◽  
O.P. Lopatin
Keyword(s):  
Particulate Matter ◽  
Diesel Engine ◽  
Natural Gas ◽  
Diesel Exhaust ◽  
Operating Conditions ◽  
Exhaust Gas ◽  
Exhaust Gases ◽  
Gas Recirculation ◽  
Total Hydrocarbons ◽  
Weight Coefficients

The results of studies of the integral toxicity of exhaust gases of a diesel engine operating on natural gas and alcohol emulsions are presented. At the same time, the regimes characterizing the specific toxicity of a diesel engine under its operating conditions were determined, and emissions of toxic components on these regimes were determined taking into account their weight coefficients. The results of research specific toxic diesel exhaust toxicity indicators, in accordance with the requirements of UNECE Regulation No. 49, show that when a diesel engine operates on natural gas with exhaust gas recirculation and an ethanol-fuel emulsion, the content of nitrogen oxides (NOx) and carbon dioxide (CO) in the exhaust gases conforms to "EURO 3", particulate matter – "EURO 5", total hydrocarbons (CHx) – "EURO 2". When the diesel engine is running on a methanol-fuel emulsion, the content of NOx, СНx and CO in the exhaust gases complies with the standards "EURO 3", particulate matter – "EURO 5".

Tuneable model predictive control of a turbocharged diesel engine with dual loop exhaust gas recirculation

2017 ◽  
Vol 232 (8) ◽  
pp. 1105-1120 ◽  
Author(s):  
Yunfan Zhang ◽  
Guoxiang Lu ◽  
Hongming Xu ◽  
Ziyang Li
Keyword(s):  
Diesel Engine ◽  
Model Predictive Control ◽  
Predictive Control ◽  
Mimo System ◽  
Exhaust Gas Recirculation ◽  
Intake Manifold ◽  
Exhaust Gas ◽  
Strong Nonlinearity ◽  
Turbocharged Diesel Engine ◽  
Gas Recirculation

The air path of a turbocharged diesel engine is a multi-input multi-output (MIMO) system with strong nonlinearity, coupling effect, delay and actuator constraints. This makes the design and tuning of the controller complex. In this paper, a tuneable model predictive control (TMPC) controller for a diesel engine’s air path with dual loop exhaust gas recirculation (DLEGR) is presented. The objective is to regulate the intake manifold pressure and exhaust gas recirculation (EGR) mass flow in each loop to meet the time-varying setpoints through coordinated control of the variable geometry turbocharger (VGT) and EGR valves. The TMPC controller adopts the design framework of an MPC controller. This controller is also able to provide a map-based switching scheme for the local controller and the controller’s weightings. A comparison between the TMPC controller and a conventional PID controller is conducted on a validated real-time engine model. The simulation results show that the TMPC controller achieves lower overshoot, faster response and a shorter settling time on the manipulated objects. These improvements are beneficial for obtaining lower fuel consumption. In order to test the capability of the TMPC controller, it is validated on a hardware in the loop (HIL) platform. The results show that the agreement between the simulation and the actual ECU’s response is good.

scholarly journals Enhancement of combustion characteristics of VCR diesel engine by optimizing engine parameters

2021 ◽  
Vol 3 (8) ◽  
Author(s):  
Prabhakara Rao Ganji ◽  
Rajesh Khana Raju Vysyaraju ◽  
Srinivasa Rao Surapaneni ◽  
B. Karuna Kumar
Keyword(s):  
Diesel Engine ◽  
Compression Ratio ◽  
Fuel Injection ◽  
Injection Pressure ◽  
Exhaust Gas Recirculation ◽  
Exhaust Gas ◽  
Performance And Emission ◽  
Start Of Injection ◽  
Fuel Injection Pressure ◽  
Gas Recirculation

AbstractIn recent years, engine emissions have been one of the important problems which are of great concern. Hence, there is a growing need to develop engines with reduced emission. In the present study, Variable Compression Ratio diesel engine model has been validated by comparing the simulation results with the experimental. The study is aimed at analyzing the effect of compression ratio, exhaust gas recirculation, fuel injection pressure and start of injection on engine performance and emission characteristics. Using composite desirability technique, the engine parameters have been optimized to achieve lower NOx, soot and ISFC. The optimum combination has been observed at Compression ratio 17.52, Start of injection −30.1 °aTDC, Fuel injection pressure 736.06 bar and Exhaust gas recirculation 28.29%. ISFC, NOx and soot are reduced by 2.37%, 29.11% and 83.81% respectively. Higher Target Fuel Distribution Index indicates the improved mixture homogeneity for the optimized parameters.

scholarly journals Experimental Investigation on Establishing the HCCI Process Fueled by N-Heptane in a Direct Injection Diesel Engine at Different Compression Ratios

2018 ◽  
Vol 10 (11) ◽  
pp. 3878 ◽  
Author(s):  
Tuan Anh ◽  
Vinh Duy ◽  
Ha Thi ◽  
Hoi Xa
Keyword(s):  
Diesel Engine ◽  
Compression Ratio ◽  
Direct Injection ◽  
Intake Manifold ◽  
Exhaust Emission ◽  
Exhaust Gas ◽  
Compression Ignition ◽  
Low Load ◽  
Cylinder Head Gasket ◽  
Gas Recirculation

Establishing the homogeneous charge compression ignition (HCCI) process in a diesel engine, in order to improve exhaust emission quality while extending the HCCI regime, is one of the challenges in applying HCCI in worldwide applications. This can be done by decreasing the compression ratio, and controlling the exhaust gas recirculation (EGR) rate and charging temperature. In this paper, an original single cylinder diesel engine was converted to n-heptane-fueled HCCI with the fuel injected into the intake manifold. At the designed compression ratio of 20:1, the HCCI engine could operate stably at low speed (from 1600 rpm to 2000 rpm) and low load (10% to 20% load). In addition, reducing the compression ratio from 20:1 to 14.87:1 by changing the thickness of the cylinder head gasket and with no EGR applied extended the operating range to 50% load and 3200 rpm speed.

scholarly journals Operational malfunctions of turbochargers – reasons and consequences

2016 ◽  
Vol 164 (1) ◽  
pp. 13-21
Author(s):  
Tadeusz DZIUBAK ◽  
Mirosław KARCZEWSKI
Keyword(s):  
Diesel Engine ◽  
Intake Manifold ◽  
Exhaust Gas ◽  
Combustion Engines ◽  
Effective Parameters ◽  
Engine Torque ◽  
Intake System ◽  
Foreign Objects ◽  
Turbocharging System ◽  
Pressure Maximum

The paper discusses the most frequently occurring types of damage in turbochargers fitted in modern combustion engines and their influence on the engine basic operational indexes. The following causes of turbocharger malfunctions have been discussed: no lubrication, low lubricant pressure, reduced lubricant quality, foreign objects in the charged air and in the exhaust gas. Example malfunctions resulting from the said causes have been shown. The experimental part discusses the influence of a reduction of the charging pressure resulting from a leakage in the intake system on the effective parameters of a diesel engine fitted in light-duty and heavy-duty vehicles. The leakage in the intake system has been simulated by boring holes of the diameter of 3 and 12 mm in the intake manifold downstream of the turbocharger. The influence has been determined of the leakage of the turbocharging system on the value of the charging pressure, maximum effective power, engine torque, unit and hourly fuel consumption and the concentration of the exhaust components. A significant impact has been observed of the leakage of the turbocharging system on the effective parameters of the tested diesel engine and exhaust gas composition.

scholarly journals Mapping of exhaust gas recirculation and combustion-residual backflow in the intake ports of a heavy-duty diesel engine using a multiplexed multi-species absorption spectroscopy sensor

2017 ◽  
Vol 19 (5) ◽  
pp. 542-552 ◽  
Author(s):  
Gurneesh Jatana ◽  
Lyle Kocher ◽  
Suk-Min Moon ◽  
Sriram Popuri ◽  
Kevin Augustin ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Diesel Engine ◽  
Absorption Spectroscopy ◽  
Exhaust Gas Recirculation ◽  
Intake Manifold ◽  
Exhaust Gas ◽  
Engine Operation ◽  
Crank Angle ◽  
Gas Recirculation

The combustion-residual backflow into the intake ports of a commercial diesel engine (Cummins ISX series) was spatiotemporally mapped using a multiplexed multi-species absorption spectroscopy sensor system; the resulting cycle- and cylinder-resolved measurements are applicable for assessing cylinder charge uniformity, control strategies, and computational fluid dynamics tools. On-engine measurements were made using four compact (3/8 in Outside Diameter) stainless steel probes which enabled simultaneous multi-point measurements, required minimal engine hardware modification, and featured a novel tip design for measurement of gas flows parallel to the probe axis. Three sensor probes were used to perform simultaneous backflow measurements in intake runners corresponding to three of the six engine cylinders, and a fourth probe was installed in the intake manifold plenum for tracking dynamics introduced by an external exhaust gas recirculation mixer. Near-crank-angle resolved measurements (5 kHz, that is, 1.2 crank angle resolution at 1000 RPM) were performed during steady-state engine operation at various levels of external exhaust gas recirculation to measure the gas properties and penetration distance of the backflow into the intake runners on a cylinder- and cycle-basis. Validation of computational fluid dynamics model results is also presented to demonstrate the utility of such measurements in advancing engine research.

scholarly journals Robust Control Approach on Diesel Engines With Dual-Loop Exhaust Gas Recirculation Systems

2010 ◽  
Author(s):  
Benjamin Haber ◽  
Junmin Wang
Keyword(s):  
Diesel Engine ◽  
Robust Control ◽  
Exhaust Gas Recirculation ◽  
Intake Manifold ◽  
Exhaust Gas ◽  
Compression Ignition ◽  
Independent Control ◽  
Control Approach ◽  
Control Authority ◽  
Gas Recirculation

This paper presents a robust control approach to achieve an independent control authority over the intake manifold conditions of a medium-duty, V8, Diesel engine with the use of a complex air-path system. The intake manifold conditions in question include gas temperature, pressure, and oxygen mass fraction. The purpose of achieving such a high control authority over these intake manifold conditions is to explore the possibilities of extending the operating ranges of advanced combustion modes like low temperature diffusion combustion (LTDC), homogenous charge compression ignition (HCCI), and pre-mixed charge compression ignition (PCCI). Independent control of these air-path variables is made possible by using a dual-loop exhaust gas recirculation (EGR) system with a two-stage, variable geometry turbocharging (VGT) system. A multi-input-multi-output robust air-path controller was designed based on a control-oriented model identified using a high-fidelity GT-Power model of a medium-duty Diesel engine. Simulation results illustrate the effectiveness of the controller over a limited engine operating range.

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