The Miller cycle effects on improvement of fuel economy in a highly boosted, high compression ratio, direct-injection gasoline engine: EIVC vs. LIVC

2014 ◽  
Vol 79 ◽  
pp. 59-65 ◽  
Author(s):  
Tie Li ◽  
Yi Gao ◽  
Jiasheng Wang ◽  
Ziqian Chen
Keyword(s):  
Compression Ratio ◽  
Fuel Economy ◽  
Gasoline Engine ◽  
Direct Injection ◽  
Miller Cycle ◽  
High Compression Ratio ◽  
High Compression ◽  
Direct Injection Gasoline Engine

Experimental study of knock combustion and direct injection on knock suppression in a high compression ratio methanol engine

Fuel ◽  
2021 ◽  
pp. 122505
Author(s):  
Qimeng Duan ◽  
Xiaojun Yin ◽  
Xiaochen Wang ◽  
Hailiang Kou ◽  
Ke Zeng
Keyword(s):  
Experimental Study ◽  
Compression Ratio ◽  
Direct Injection ◽  
High Compression Ratio ◽  
High Compression

scholarly journals Experimental study on the effects of the Miller cycle on the performance and emissions of a downsized turbocharged gasoline direct injection engine

2020 ◽  
Vol 12 (5) ◽  
pp. 168781402091872
Author(s):  
Zhao-Ming Huang ◽  
Kai Shen ◽  
Li Wang ◽  
Wei-Guo Chen ◽  
Jin-Yuan Pan
Keyword(s):  
Compression Ratio ◽  
Fuel Economy ◽  
Direct Injection ◽  
Gasoline Direct Injection ◽  
Miller Cycle ◽  
Power Performance ◽  
Direct Injection Engine ◽  
Performance And Emission ◽  
Gasoline Direct Injection Engine ◽  
Partial Load

The Miller cycle has been proven to be an effective way to improve the thermal efficiency for gasoline engines. However, it may show insufficient power performance at certain loads. In this study, the objective is to exploit the advantages of the Miller-cycle engines over the original Otto-cycle engines. Therefore, a new camshaft profile with early intake valve closure was devised, and two various pistons were redesigned to obtain higher compression ratio 11.2 and 12.1, based on the original engine with compression ratio 10. Then, a detailed comparative investigation of the effects of Miller cycle combined with higher compression ratio on the performance and emission of a turbocharged gasoline direct injection engine has been experimentally carried out based on the engine bench at full and partial loads, compared to the original engine. The results show that, at full load, for a turbocharged gasoline direct injection engine utilizing the Miller cycle, partial maximum power is compromised about 1.5% while fuel consumption shows a strong correlation with engine speed. At partial load, since the Miller effect can well reduce the pumping mean effective pressure, thus improves the fuel economy effectively. In addition, the suppression of the in-cylinder combustion temperature induced by the lower effective compression ratio contributes to the reduction of nitrogen oxide emission greatly. However, the total hydrocarbon emission increases slightly. Therefore, a combination of the Miller cycle and highly boosted turbocharger shows great potential in further improvement of fuel economy and anti-knock performance for downsized gasoline direct injection engines.

scholarly journals Analysis of Fuel Economy in Petrol Engines Due To High Compression of Steppes

2020 ◽  
Vol 9 (1) ◽  
pp. 1744-1748
Keyword(s):  
Internal Combustion Engine ◽  
Compression Ratio ◽  
Fuel Economy ◽  
Gasoline Engine ◽  
Combustion Engine ◽  
Internal Combustion ◽  
High Compression ◽  
The Relationship ◽  
Thermodynamic Processes

All known automotive concerns and institutes specialized in ICE problems have worked to identify the relationship between the compression ratio of ICE and its efficiency and to investigate the nature of thermodynamic processes taking place in ICE. Numerous experiments have also been carried out to increase the compression ratio of ICE. But these works had a negative result. Building on this negative result, ICE theory adopted, as axioms, claims that the compression ratio of a gasoline engine cannot be higher than 14. That the most effective compression ratio of the diesel internal combustion engine is in the region 17-23, and at the compression ratio 40 it becomes zero. Experts and theorists were so established in the correctness of these provisions that at this stage the slightest attempt to question them caused a sharp reaction.

Limits of compression ratio in spark-ignition combustion with methanol

2021 ◽  
pp. 146808742110433
Author(s):  
Christian Wouters ◽  
Patrick Burkardt ◽  
Stefan Pischinger
Keyword(s):  
Compression Ratio ◽  
Direct Injection ◽  
Spark Ignition ◽  
Combustion Stability ◽  
High Compression Ratio ◽  
Lean Burn ◽  
Promising Alternative ◽  
Excess Air ◽  
High Compression ◽  
Lean Limit

A shift toward a circular and [Formula: see text]-neutral world is required, in which rapid defossilization and lower emissions are realized. A promising alternative fuel that has gained traction is methanol, thanks to its favorable and clean-burning fuel properties as well as its ability to be produced in a carbon-neutral process. Especially methanol’s high knock resistance and its combustion stability offer the opportunity to operate an engine at both a high compression ratio and a high excess air dilution. Although methanol has been investigated in series-production engines for passenger car applications, there is a lack of investigations on a dedicated engine that can operate at methanol’s knock limit. In this paper, methanol’s knock limitation is experimentally assessed by applying high compression ratios to a direct injection spark-ignition single-cylinder research engine. To that end, four compression ratios were investigated: 10.8, 15.0, 17.7, and 20.6. With compression ratios of 15.0 and 17.7, the lean-limit was increased to excess air ratios of 2.0 and 2.1, respectively, compared to 1.7 at a compression ratio of 10.8. For the highest compression ratio of 20.6, the maximum lean burn limit was increased to an excess air ratio of 1.9 due to achieving the maximum cylinder pressure limit. Despite the minor increase in lean-limit, a maximum indicated efficiency of 48.7% was achieved with the highest compression ratio of 20.6. However, even at this high compression ratio, methanol did not show a knock limitation. The investigations in this work provide profound knowledge for future engine investigations with methanol.

209 Effects of combustion systems and various hydrocarbons on performance of high compression ratio gasoline engine

2012 ◽  
Vol 2012.51 (0) ◽  
pp. 55-56
Author(s):  
Takahiro KAWADA ◽  
Shingo OKAYA ◽  
Jin KUSAKA ◽  
Takashi YOUSO ◽  
Masahisa YAMAKAWA ◽  
...  
Keyword(s):  
Compression Ratio ◽  
Gasoline Engine ◽  
High Compression Ratio ◽  
High Compression ◽  
Combustion Systems
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