The Effects of Engine Variables and Exhaust Gas Recirculation on Emissions, and Fuel Economy - Part IV

1978 ◽  
Author(s):  
P. W. Kirklin ◽  
S. S. Wise
Keyword(s):  
Fuel Economy ◽  
Exhaust Gas Recirculation ◽  
Exhaust Gas ◽  
Gas Recirculation

Effect of balance valve on an asymmetric twin-scroll turbine for heavy-duty diesel engine

2020 ◽  
pp. 146808742093016
Author(s):  
Jianjiao Jin ◽  
Jianfeng Pan ◽  
Zhigang Lu ◽  
Qingrui Wu ◽  
Lizhong Xu
Keyword(s):  
Fuel Economy ◽  
High Speed ◽  
Engine Speed ◽  
Flow Parameter ◽  
Engine Performance ◽  
Exhaust Gas Recirculation ◽  
Exhaust Gas ◽  
Engine Fuel ◽  
Recirculation Rate ◽  
Gas Recirculation

A conventional asymmetric twin-scroll turbine with wastegate is capable of effectively tackling down the contradiction between fuel economy degradation and low nitrogen oxide emissions. However, as the engine speed has been rising at middle- and high-speed ranges, the pressure of small scroll inlet will be increasingly higher as compared with the intake pressure, thereby worsening fuel economy. In this study, a novel turbocharging technology of asymmetric twin-scroll turbine with a balance valve was first analyzed to more effectively balance the engine fuel economy and emission. The experiments on turbine test rig and engine performance were performed to explore the effects of balance valve on turbine performance, asymmetric ratio, exhaust gas recirculation rate, as well as engine performance. As the balance valve open degree was elevated, the turbine flow parameter was being extended, while the turbine efficiency was enhanced. Moreover, a lower asymmetric ratio could lead to a broader flow parameter range between that of partial admission and equal admission, thereby resulting in a broader regulating range of exhaust gas recirculation rate. In contrast with the asymmetric twin-scroll turbine with wastegate, the turbine running efficiency of asymmetric twin-scroll turbine with balance valve was enhanced by nearly 2%–11% at middle and high engine speed ranges, while the fuel economy was improved by nearly 1.5%–8%.

Effects of high-pressure and donor-cylinder exhaust gas recirculation on fuel economy and emissions of marine diesel engines

Fuel ◽  
2022 ◽  
Vol 309 ◽  
pp. 122226
Author(s):  
Xuyang Tang ◽  
Peng Wang ◽  
Zhongyuan Zhang ◽  
Fengli Zhang ◽  
Lei Shi ◽  
...  
Keyword(s):  
High Pressure ◽  
Fuel Economy ◽  
Diesel Engines ◽  
Exhaust Gas Recirculation ◽  
Exhaust Gas ◽  
Marine Diesel ◽  
Gas Recirculation

Development of a Miller cycle engine with single-stage boosting and cooled external exhaust gas recirculation

2016 ◽  
Vol 231 (6) ◽  
pp. 766-780 ◽  
Author(s):  
Yongsheng He ◽  
Jim Liu ◽  
Bin Zhu ◽  
David Sun
Keyword(s):  
Fuel Consumption ◽  
Compression Ratio ◽  
Fuel Economy ◽  
Exhaust Gas Recirculation ◽  
Operating Conditions ◽  
Single Stage ◽  
Exhaust Gas ◽  
Brake Specific Fuel Consumption ◽  
Miller Cycle ◽  
Gas Recirculation

In this paper, the development of a Miller cycle gasoline engine which has a high compression ratio from 11.5:1 to 12.5:1, single-stage turbocharging and external cooled exhaust gas recirculation is described. The improvement in the fuel economy by adding external cooled exhaust gas recirculation to the Miller cycle engine at different geometric compression ratios were experimentally evaluated in part-load operating conditions. The potential of adding external cooled exhaust gas recirculation in full-load conditions to mitigate pre-ignition in order to allow higher geometric compression ratios to be utilized was also assessed. An average of 3.2% additional improvement in the fuel economy was achieved by adding external cooled exhaust gas recirculation to the Miller cycle engine at a geometric compression ratio of 11.5:1. It was also demonstrated that the fuel consumption of the engine with external cooled exhaust gas recirculation was reduced by 3–7% in a wide range of part-load operating conditions and that the engine output of the Miller cycle engine at a geometric compression ratio of 12.5:1 increased at 2000 r/min in the full-load condition. The Miller cycle engine with external cooled exhaust gas recirculation at a geometric compression ratio of 12.5:1 achieved a broad brake specific fuel consumption range of 220 g/kW h or lower, with the lowest brake specific fuel consumption of 215 g/kW h. While there are still challenges in implementing external cooled exhaust gas recirculation, the Miller cycle engine with single-stage turbocharging and external cooled exhaust gas recirculation showed its potential for substantial improvement in the fuel economy as one of the technical pathways to meet future requirements in reducing carbon dioxide emissions.

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