A Study on the Characteristics of Natural Gas Combustion at a High Compression Ratio by Using a Rapid Compression and Expansion Machine

2012 ◽  
Author(s):  
Akira Kikusato ◽  
Hiroyuki Fukasawa ◽  
Kazutoshi Nomura ◽  
Jin Kusaka ◽  
Yasuhiro Daisho
Keyword(s):  
Natural Gas ◽  
Compression Ratio ◽  
High Compression Ratio ◽  
Gas Combustion ◽  
High Compression ◽  
Compression And Expansion ◽  
Rapid Compression ◽  
Natural Gas Combustion

Operation of a Spark Ignition Engine With High Compression Ratio Using Biogas Blended With Natural Gas, Propane, and Hydrogen

2018 ◽  
Vol 141 (5) ◽  
Author(s):  
Juan Pablo Gómez Montoya ◽  
Andrés A. Amell ◽  
Daniel B. Olsen
Keyword(s):  
Natural Gas ◽  
Output Power ◽  
Compression Ratio ◽  
Maximum Output Power ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Maximum Output ◽  
High Compression Ratio ◽  
Operational Conditions ◽  
High Compression

This research evaluated the operational conditions for a diesel engine with high compression ratio (CR) converted to spark ignition (SI), under stable combustion conditions close to the knocking threshold. The main fuel used in the engine was biogas, which was blended with natural gas, propane, and hydrogen. The engine limit to test the maximum output power was using the knocking threshold; just below the knocking threshold, the output power and generating efficiency are the highest for each blend. Leaner mixtures increased the engine knocking tendency because the required increase in the % throttle reduced the pressure drop at the inlet stroke and increased the mixture pressure at the end of the compression stroke, which finally reduced the ignition delay time of the end gas and increased the knocking tendency of the engine for all the blends. Therefore, the output power should be decreased to operate the engine below to the knocking threshold. Purified biogas achieved the highest output power and generating efficiency compared with the other blends and the original diesel operation; this blend was operated with five equivalence ratios. Purified biogas exhibits an optimal balance between knocking resistance, low heating value, flame speed, and energy density.

scholarly journals Combustion and energy distribution of hydrogen-enriched compressed natural gas engines with low heat rejection based on Atkinson cycle

2019 ◽  
Vol 11 (1) ◽  
pp. 168781401881958 ◽  
Author(s):  
Yang Liu ◽  
Yituan He ◽  
Cuijie Han ◽  
Chenheng Yuan
Keyword(s):  
Natural Gas ◽  
Heat Loss ◽  
Compression Ratio ◽  
Thermal Efficiency ◽  
High Compression Ratio ◽  
Compressed Natural Gas ◽  
Heat Rejection ◽  
Natural Gas Engines ◽  
High Compression ◽  
Atkinson Cycle

In order to reduce the heat loss and improve the indicated thermal efficiency of hydrogen-enriched compressed natural gas engines, this article presents a combination of Atkinson cycle with high compression ratio and low heat rejection on the hydrogen-enriched compressed natural gas prototype engine with 55% hydrogen blend. The combustion characteristics and energy distribution of the prototype and modified engines were investigated by simulation, and the conclusions are as follows: the pressure and temperature of modified engines are higher than those of the prototype during the combustion process. Compared with the prototype, the modified engines present lower peak heat release rate, but faster combustion after ignition, and their CA50 are closer to top dead center. Although the high compression ratio engine with Atkinson cycle generates more heat loss, its indicated thermal efficiency still increases by 0.6% with the decrease in the exhaust energy. Furthermore, the high compression ratio engine with low heat rejection and Atkinson cycle combines the advantages of low heat loss and relatively longer expansion stroke, so its heat loss reduces obviously, and 61.6% of the saved energy from low heat rejection and Atkinson cycle can be converted into indicated work that indicates a 4.5% improvement in indicated thermal efficiency over the prototype, which makes it perform better in terms of power and fuel economy simultaneously.

Study on the combustion characteristics of a high compression ratio HCCI engine fueled with natural gas

Fuel ◽  
2019 ◽  
Vol 255 ◽  
pp. 115701 ◽  
Author(s):  
Zhongshu Wang ◽  
Guizhi Du ◽  
Zhijie Li ◽  
Xiaoyan Wang ◽  
Dan Wang
Keyword(s):  
Natural Gas ◽  
Compression Ratio ◽  
Combustion Characteristics ◽  
High Compression Ratio ◽  
Hcci Engine ◽  
High Compression

Research of pressure influence in the gas supply system on the energy consuption level of gas devices

2019 ◽  
Vol 6 (2) ◽  
pp. 56-63
Author(s):  
L. D. Pylypiv ◽  
І. І. Maslanych
Keyword(s):  
Natural Gas ◽  
Residential Buildings ◽  
Supply System ◽  
Normal Operation ◽  
Gas Combustion ◽  
Efficient Operation ◽  
Gas Consumption ◽  
Natural Gas Combustion ◽  
Gas Supply

There are investigated the influence of operating pressures in the gas supply system on the level of such energy indicators as efficiency, gas flow and gas overrun by gas equipment in residential buildings. There is established a relationship between the values of operating pressures in the gas supply system and the gas consumption level of household appliances. The causes of insufficient pressure in the gas networks of settlements are analyzed in the article. There is also developed an algorithm for calculating the change in the efficiency of gas appliances depending on the operational parameters of the gas network. It has been found that the most efficient operation of gas appliances is observed at an overpressure at the inlet of gas appliances of about 1200 Pa.To ensure the required quality of natural gas combustion among consumers and minimize gas consumption there are justified the following measures in the article: coordinating a domestic regulatory framework for assessing the quality of natural gas with international norms and standards; improving the preparation of gas coming from local wells before supplying it to gas distribution networks; auditing low pressure gas pipelines and reconstructing areas affected by corrosion; ensuring standard gas pressure in the network for the normal operation of domestic gas appliances; stating quality indicators of natural gas combustion by gas sales organizations.

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