The Diesel Engine for Cars—Is There a Future?

1998 ◽  
Vol 120 (3) ◽  
pp. 641-647 ◽  
Author(s):  
F. F. Pischinger

The diesel engine is known as the most fuel efficient combustion engine. Its acceptance for use in passengers cars, however, varies geographically. Today, the diesel car plays an important role in Europe; in France, for instance, it is achieving a remarkable market share of about 42 percent, while in the US its market penetration can be neglected. Many questions are expressed concerning the future of diesel powered cars. The question affecting market acceptance is as follows: can the significantly better fuel efficiency of a diesel car outweigh perceived detrimental characteristics? Such unfavorable properties are thought to be low specific power, objectionable noise, higher exhaust emissions (including smoke), and higher vehicle price. These features are closely influenced by the state of passenger car diesel engine technology. This technology state and its potential must be evaluated with respect to current and future demands, for instance, tighter exhaust emission regulations. In addition, the commercial value and consumer acceptance of high fuel economy must be evaluated. It is clear that the ultimate result of weighing the pros and cons will depend not only on technological factors, but also on political factors such as fuel taxation. Regarding the state of technology, the diesel car is very promising. First, by employing a direct injection combustion system, the fuel efficiency can be improved by about 15 percent over current swirl chamber engines. Furthermore, the specific power (hp/ltr) can be increased by efficient supercharging to achieve values of today’s gasoline engines. By tuning the combustion system, low noise engine design features and incorporation of careful noise reduction measures on the vehicle, the noise behavior of a spark ignited vehicle can be reached. Exhaust emissions can currently be reduced to a level to satisfy today’s European and US Tier 1 emission limits. However, significant development effort remains. More stringent emission levels (California US, Tier 2 ULEV, and Stage 3 in Europe) require further advancements in diesel combustion. The strong development potential of 4-value engines and new unique injection systems is evident. In addition, there are promising developments with lean NOx catalysts and regenerative particulate filters. These technologies offer the potential to meet the very stringent future emission standards. It is anticipated that the sophisticated technology needed to meet these standards will make the future diesel car more expensive compared to a gasoline fueled vehicle. This raises the issue of what price will the consumer pay for the higher fuel economy of a diesel car. In light of the worldwide rapid increase in passenger car population and of the dwindling oil reserves and their global distribution, the fuel efficient diesel engine will play an important role in the future of passenger cars.

Author(s):  
A. K. Kathpal ◽  
Anirudh Gautam ◽  
Avinash Kumar Agarwal ◽  
R. Baskaran

The diesel fuel-injection system of ALCO DLW 251 engine consists of single cylinder injection pumps, delivery pipes, and fuel injector nozzles. Fuel injection into the combustion chamber through multi-hole nozzles delivers designed power and fuel efficiency. The two most important variables in a fuel injection system of a diesel engine are the injection pressure and injection timing. Proper timing of the injection process is essential for satisfactory diesel engine operation and performance. Injection timing needs to be optimised for an engine based on requirements of power, fuel economy, mechanical and thermal loading limitations, smoke and emissions etc. Since each of these requirements varies with the operating conditions, sometimes contrary to the requirements of the other parameters, the map of optimised injection timing can be very complex. The ALCO DLW 251 engine’s fuel injection pump is jerk type to permit accurate metering and timing of the fuel injected. The pump has a ported barrel and constant-stroke plunger incorporating a bottom helix for fuel delivery control with constant injection timing. From the point of view of good power and fuel economy, combustion should take place so that the peak firing pressure occurs at about 10–15° after TDC and is usually a few degrees after combustion starts. For this to happen, fuel should be injected at an appropriate time, depending on Injection delay and Ignition delay. Both these factors are dependent on the speed and load. Changing the operating point of the engine may change either one or both types of delay, altering the moment of start of combustion. Various researchers have shown that both the Injection and the Ignition delay are reduced as the engine speed is decreased resulting in advancement of injection timing at lower speeds (and loads). This condition will be corrected by varying the static injection timing, which can be achieved by providing a modified helix on the plunger to delay the start of fuel injection, for the lower speeds and loads. A new double helix (upper and lower helix) fuel injection pump for the ALCO DLW 251 16 V engine has been designed. The new fuel injection pump has been tested on the engine test cell at Research Designs & Standards Organisation and has shown an improvement of 1.2% in locomotive duty cycle fuel consumption. This paper describes the design & development of double helix fuel injection pump and discusses the engine tests completed to verify the projected improvements in fuel efficiency.


2013 ◽  
Author(s):  
Prakash Kamat ◽  
Yogesh Aghav ◽  
Nitin Gokhale ◽  
Vikas Helchel ◽  
Ajit Patil ◽  
...  

2000 ◽  
Author(s):  
K. M. Jefferd ◽  
J. S. Rogerson ◽  
D. E. Copp ◽  
R. L. Brundle ◽  
M. A. Huntly

Author(s):  
Pingen Chen ◽  
Junmin Wang

The applications of diesel engines in ground vehicles have attracted much attention over the past decade for the reasons of outstanding fuel economy, power capability, and reliability. With the increasing demand of less greenhouse gas emissions, the current diesel engine fuel efficiency remains unsatisfactory partially due to the conflict between the engine fuel efficiency and engine-out NOx emissions. While advanced aftertreatment systems, such as selective catalytic reduction (SCR) systems or lean NOx trap, have been integrated to diesel engines for reducing the tailpipe NOx emissions, the integrated controls for coordinating diesel engine and SCR system to achieve high engine efficiency and low tailpipe emissions are still limited. The purpose of this study is to develop such an integrated diesel engine and SCR system control method using nonlinear model predictive control (NMPC) approach with both start of injection (SOI) timing and urea solution injection rate as the control inputs. Control-oriented engine models were developed to quantify the influences of SOI timing on engine efficiency and engine-out NOx emissions. Simulation results under US06 driving cycle demonstrate that, given the same catalyst size in total, the proposed controllers are capable of reducing total engine fuel consumption over the driving cycle by 9.36% and 9.50%, respectively, for lumped SCR system and two-cell SCR system, while maintaining high NOx conversion efficiencies and low tailpipe ammonia slip.


2012 ◽  
Vol 5 (3) ◽  
pp. 1426-1435 ◽  
Author(s):  
Ashok Permude ◽  
Mehul Pathak ◽  
Venkatesh Kumar ◽  
Sachleen Singh

Sign in / Sign up

Export Citation Format

Share Document