Ion Current Detection During Cold Starting and Idling in Diesel Engines

2012 ◽  
Author(s):  
Sanket Gujarathi ◽  
Tamer Badawy ◽  
Naeim Henein
Keyword(s):  
Feedback Control ◽  
Signal Detection ◽  
Fuel Consumption ◽  
Diesel Engines ◽  
Ion Current ◽  
Current Signal ◽  
Gasoline Engines ◽  
Cold Starting ◽  
High Concentrations ◽  
Current Detection

Cold starting of diesel engines is characterized by inherent problems such as long cranking periods and combustion instability leading to an increase in fuel consumption and the emission of high concentrations of hydrocarbons which appear as white smoke. The ion current signal has been considered for the feedback control of both gasoline and diesel engines. However, the ion current signal produced from the combustion of the heterogeneous charge in diesel engines is weaker compared to that produced from the combustion of the homogeneous charge in gasoline engines. This presents a problem in the detection of the ion current signal in diesel engines, particularly during starting and idling operations. This paper investigates and addresses the ion current detection problems pertaining to cold starting and various idling speeds. Also, different approaches have been investigated to improve the signal detection under these conditions.

The Detection System of Adaptive Electrochemical Micro Electric Current

2013 ◽  
Vol 313-314 ◽  
pp. 304-307
Author(s):  
Sheng Qian Ma ◽  
Man Hong Fan
Keyword(s):  
Signal Detection ◽  
Detection System ◽  
Current Signal ◽  
Weak Current ◽  
Large Size ◽  
Detection Circuit ◽  
Circuit Structure ◽  
Electrochemical Current ◽  
High Degree ◽  
Current Detection

The existing micro current detecting apparatus is of large size and is manual controlled. When the detected currents sensitivity is higher, however, stability will be worse. In order to solve this problem, an adaptive detection system is proposed in this paper. The system designed a micro current signal detection circuit based on OK6410 embedded with development board. The Weak current signal is collected with the high precision ADC. Automatic adjustment circuit gain is from 1 to 10000. Spectrometer wavelength size is changed in real-time. Current resolution can reach nA. The experimental results show that this system can collect the micro current effectively. The main characteristics of the system are simple circuit structure, small volume, high degree of automation, and strong reliability, and it greatly improves the anti-interference performance of the circuit. The system can not only be applied in electrochemical current detection, but also be widely used in weak signal detection.

3D CFD Modeling and Validation of Ion Current Sensor in a Gen-Set Diesel Engine Using Chemical Kinetic Mechanism

2016 ◽  
Author(s):  
Tamer Badawy ◽  
Naeim Henein
Keyword(s):  
Diesel Engine ◽  
Combustion Chamber ◽  
Diesel Engines ◽  
Combustion Process ◽  
Ion Current ◽  
Cfd Modeling ◽  
Ionization Mechanism ◽  
Current Signal ◽  
Current Sensing ◽  
Cycle Simulation

The control of the combustion process is becoming a necessity for diesel engines in order to meet the upcoming stringent emission regulations. Ion current sensing technology has the potential to provide real-time feedback of the combustion process while using a fairly inexpensive sensor. 3D computational fluid dynamics (CFD) cycle simulation is becoming more complementary in understanding the complex combustion process in diesel engines. In this paper, a CFD study is focused on investigating the characteristics of the ion current signal produced during the combustion process of a Gen-set turbocharged diesel engine. Multiple virtual ion sensing probes are defined in different locations inside the combustion chamber to understand the influence of sensor location on signal characteristics. The n-heptane reaction mechanism and NO mechanism, combined with an ionization mechanism developed at WSU with 11 species, are used in the model to predict the chemical kinetics of combustion and the mole fraction of ionized species produced during combustion. Since the charge in diesel engines is heterogeneous and due to the sensing nature of the ion sensor, this paper explores the effect of sensor sensing diameter and its protrusion depth inside the combustion chamber on the ion current signal development. The simulation is validated by comparing in-cylinder pressure traces, the rate of heat release, and the ion current signal. Further, the model results are validated under different engine loads and injection pressures. This study utilizes the ionization mechanism to give further understanding of the complex formation of ionization species and their amplitudes, particularly at local sensing locations. This can be very vital to identify the potentials of using the ion current sensing and highlight its viability in feedback closed loop combustion control.

scholarly journals The efficiency engine – cost-effective alternative to downsizing

2012 ◽  
Vol 149 (2) ◽  
pp. 3-9
Author(s):  
Michael WEISSBÄCK ◽  
Mike HOWLETT ◽  
Norbert AUSSERHOFER ◽  
Stefan KRAPF
Keyword(s):  
Diesel Engine ◽  
Fuel Consumption ◽  
Power Density ◽  
Diesel Engines ◽  
Peak Pressure ◽  
Cost Effective ◽  
Gasoline Engines ◽  
Moderate Power ◽  
Cost Effective Alternative ◽  
Efficiency Engine

As an alternative to the familiar option of downsizing diesel engines, AVL has developed the so-called efficiency engine in collaboration with Renault. Because of the engine’s moderate power density, its peak pressure requirements are lower in some areas than those of turbocharged gasoline engines. Consequently, its mechanical friction and fuel consumption can be significantly reduced, as the comparison with a conventional and a downsized diesel engine demonstrates.

In-cycle combustion feedback control for abnormal combustion based on digital ion current signal

2017 ◽  
Vol 19 (2) ◽  
pp. 241-249 ◽  
Author(s):  
Yintong Liu ◽  
Jun Deng ◽  
Zongjie Hu ◽  
Liguang Li
Keyword(s):  
Feedback Control ◽  
Direct Injection ◽  
Gasoline Direct Injection ◽  
Ion Current ◽  
Processing Unit ◽  
Current Signal ◽  
Post Processing ◽  
Direct Injection Engine ◽  
Gasoline Direct Injection Engine

For better stability of ion current employed for in-cycle combustion diagnosis and feedback control, this research develops a digital post-processing unit for in-cylinder ion current signals. Based on the processed digital ion current signal, abnormal combustion in gasoline direct injection engine is successfully detected, and the in-cycle remedy feedback control is achieved as well. Both re-ignition and re-injection are utilized for misfiring remedy, and only re-injection is employed for knocking inhibition. The accuracy of misfiring diagnosis is achieved no less than 94%, and the re-injection combined with re-ignition operation is shown to be feasible for misfiring remedy as well. The accuracy of knocking diagnosis is around 85% (knocking rate = 20%). The re-injection under the pre-knocking condition is shown to be effective for knocking inhibition.

Experimental Study of Ion Current Signals and Characteristics in an Internal Combustion Rankine Cycle Engine Based on Water Injection

2018 ◽  
Vol 140 (11) ◽  
Author(s):  
Zhe Kang ◽  
Zhijun Wu ◽  
Lezhong Fu ◽  
Jun Deng ◽  
Zongjie Hu ◽  
...  
Keyword(s):  
Water Vapor ◽  
Water Injection ◽  
Rankine Cycle ◽  
Internal Combustion ◽  
Operating Conditions ◽  
Ion Current ◽  
Pure Oxygen ◽  
Current Signal ◽  
Injection Process ◽  
Current Detection

The internal combustion Rankine cycle (ICRC) engine utilizes pure oxygen as the oxidant instead of air during combustion to prevent the generation of nitrogen oxide emissions and lower the cost of CO2 recovery. To control combustion intensity and increase efficiency, water injection technology is implemented as it can increase the in-cylinder working fluid during combustion process. To further enhance the system thermal efficiency, the injected water is heated using coolant and waste heat before being directly injected into combustion chamber. The main challenge of controlling the ICRC engine is the interaction between water injection process and combustion stability. Ion current detection provides a potential solution of real-time detection of in-cylinder combustion status and water injection process simultaneously. In this paper, the characteristics of ion current signal in an ICRC engine were studied. The results indicate the ion current signal is primarily affected by the combination of trapped water vapor injected in the last cycle and in-cylinder combustion intensity. The water vapor contributes to the ionization reactions, which lead to enhanced ion current signals under water cycle. The ion current signal is capable of reflecting the operating conditions of the in-cylinder water injector. The phase of the ion current peak value has a linear relation as the water injection timing is delayed, and ion current detection technology has the potential to detect the combustion phase under different engine loads in an internal combustion Rankine cycle engine.

An Improvement of Part Load Performance of Diesel Engines Operating at Constant Speed Conditions

1994 ◽  
Vol 208 (1) ◽  
pp. 21-25 ◽  
Author(s):  
A A Abdel-Rahman ◽  
M K Ibrahim ◽  
A A Said
Keyword(s):  
Fuel Consumption ◽  
Diesel Engines ◽  
Petroleum Refining ◽  
Specific Fuel Consumption ◽  
Constant Speed ◽  
Maximum Pressure ◽  
Brake Specific Fuel Consumption ◽  
Part Load ◽  
Generating Sets ◽  
In Series

This paper discusses the possibility of improving the part load performance of diesel electric turbocharged engines operating at constant speed conditions. A sequential turbocharged system is proposed, where the compressors are connected In series. The study focused on two turbocharged diesel–electric generating sets existing at Ameria Petroleum Refining Company in Alexandria, Egypt. The results of the prediction showed that, at part load, both the maximum pressure and temperature were increased, and the brake specific fuel consumption was reduced considerably (by about 10 per cent).

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