scholarly journals Operational malfunctions of turbochargers – reasons and consequences

2016 ◽  
Vol 164 (1) ◽  
pp. 13-21
Author(s):  
Tadeusz DZIUBAK ◽  
Mirosław KARCZEWSKI

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.

2017 ◽  
Vol 171 (4) ◽  
pp. 269-273
Author(s):  
Jerzy CISEK

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


2011 ◽  
Vol 63-64 ◽  
pp. 237-240
Author(s):  
Qi Xin Sun ◽  
Limin Chen

In recent years, the internal combustion engine has been widely used through technological advances to improve its environmental performance. Mechanical and electrical integration of the engine turbocharging system is based on conventional turbocharging system to increase motor in parallel with the turbocharger and the corresponding reversible energy storage components, so that achieve by adjusting the energy input or output direction and the size of the motor to adjust the exhaust turbocharger operating point and the gas supply function. According to matching requirements of light vehicle diesel engine, the analysis model of exhaust gas energy is obtained through qualitative analysis of exhaust gas energy in turbocharged diesel engine.


2019 ◽  
Vol 252 ◽  
pp. 05012
Author(s):  
Łukasz Grabowski ◽  
Konrad Pietrykowski ◽  
Paweł Karpiński

The analysis of the distribution of thermal energy generated during the combustion process in internal combustion engines and the estimation of individual losses are important regarding performance and efficiency. The article analyses the energy balance of the designed two-stroke opposed piston diesel engines with offset, i.e. the angle by which the crankshaft at the side of exhaust ports is ahead of the crankshaft at the side of intake ports. Based on the developed zero-dimensional engine model, a series of simulations were performed in steady-state conditions using the AVL BOOST software. The values of individual energy losses, including cooling losses, exhaust gas losses, friction losses were obtained. The influence of decreasing and increasing the offset on the performance of the tested engine was analysed.


Author(s):  
Jaspreet Hira ◽  
Basant Singh Sikarwar ◽  
Rohit Sharma ◽  
Vikas Kumar ◽  
Prakhar Sharma

In this research work, a surge tank is developed and utilised in the diesel engine for controlling the NOX emission. This surge tank acts as a damper for fluctuations caused by exhaust gases and also an intercooler in reducing the exhaust gas temperature into the diesel engine intake manifold. With the utilisation of the surge tank, the NOX emission level has been reduced to approximately 50%. The developed surge tank is proved to be effective in maintaining the circulation of water at appropriate temperatures. A trade-off has been established between the engine performance parameters including the brake thermal efficiency, brake specific fuel consumption, exhaust gas temperature and all emission parameters including HC and CO.


2021 ◽  
Vol 2061 (1) ◽  
pp. 012065
Author(s):  
I I Libkind ◽  
A V Gonturev

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.


Author(s):  
Yunfan Zhang ◽  
Guoxiang Lu ◽  
Hongming Xu ◽  
Ziyang Li

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.


Energies ◽  
2017 ◽  
Vol 10 (11) ◽  
pp. 1888
Author(s):  
Zhaojie Shen ◽  
Wenzheng Cui ◽  
Xiaodong Ju ◽  
Zhongchang Liu ◽  
Shaohua Wu ◽  
...  

2014 ◽  
Vol 70 (1) ◽  
Author(s):  
A. Supee ◽  
R. Mohsin ◽  
Z. A. Majid ◽  
M. I. Raiz

In Diesel-CNG (Compressed Natural Gas) Dual Fuel (DDF) system, CNG is generally inducted in the intake manifold by CNG injector which is mounted on the intake manifold whereas diesel fuel is directly injected into engine cylinder using existing diesel fuel injector system. Status quo of optimum CNG injector position on intake manifold will  provide better gaseous fuel mixing quality, produce high turbulence kinetic energy and thus improve the performance of the diesel engine under DDF system. Thus, under full load condition at 2750 rpm, the engine performance and exhaust gas emissions tests such as nitric oxides (NOx), carbon dioxide (CO2), carbon monoxide (CO) and hydrocarbon (HC) were conducted on a diesel engine under DDF system for optimization of CNG injector position. Four CNG injector position on intake manifold were selected and optimum position of CNG injector was found to be at "position 2" which results in higher power output and less exhaust gas emissions. Further analysis by Computational Fluid Dynamics (CFD) shows that CNG injector at "position 2" exhibit better quality of homogeneous CNG-air mixture and higher turbulence kinetic energy compared to other position. Based on the findings, an optimization of CNG injector position on intake manifold provide promising modification method due to the simple, cheaper and commercially acceptable.


2019 ◽  
Vol 20 (1-2) ◽  
pp. 241-245
Author(s):  
Karol Grab-Rogaliński

One of the major problems in internal combustion engines is emission of pollutants with exhaust gases. Those pollutants are not only harmful for environment but also for humans. To decrease emission of pollutants many mechanical and chemical methods are used in internal combustion engines especially in exhaust system such as TWC, DPF, SCR. Alternative way for decrease in exhaust gas pollutants is use of alternative fuel as a primary energy carrier or as an additional fuel for base hydrocarbon one. In this studies the hydrogen was used as a additional fuel to methane. Both fuels were delivered to intake manifold. The share of the fuel was 100/0 methane/hydrogen and 70/30 methane/hydrogen. The addition of hydrogen to base fuel shown decrease of exhaust pollutants from engine and increase in engine operating parameters.


Author(s):  
Kareem Emara ◽  
Ahmed Emara ◽  
Elsayed Abdel Razek

As the intake system design is significant for the optimal performance of internal combustion engines, this work aims to optimize the geometry of an intake system in a direct injection (DI) diesel engine. The study concerns the geometry effects of three different intake manifolds mounted consecutively on a fully instrumented, six cylinders, in line, water cooled, 19.1 liters displacement, DI heavy duty diesel engine. A 3D numerical simulation of the turbulent flow through these manifolds is applied. The model is based on solving Navier-Stokes and energy equations in conjunction with the standard K-ε turbulence model and hypothetical boundary conditions using ANSYS- CFX 15. Numerical results of this simulation are presented in the form of flow field velocity as well as pressure field. Optimal design of the intake system is performed and the modeling made it possible to provide a fine knowledge of in-flow structures, in order to examine the adequate manifold. Engine performance characteristics such as brake torque, brake power, thermal efficiency and specific fuel consumption are also carried out to evaluate the effects of the variation in the intake manifold geometry and to validate the optimal design. Simulation and experimental results confirmed the effectiveness of the optimized manifold geometry on the engine performances.


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