China
Africa
Explore chapters and articles related to this topic
The End of Compromise
Published in Patrick Hossay, Automotive Innovation, 2019
Defining the CR of an engine has long been the very epitome of automotive engineering trade-offs. An engine’s compression ratio is not a variable that can typically be altered, like timing or fuel mixture; it is fundamental to the engine design. So, it needs to be defined carefully at the start. At lighter loads and lower engine speeds, a high compression ratio can provide improved fuel consumption, since higher compression means higher efficiency. An increase in the CR from 8 to 12 might produce a 20% or more improvement in an engine’s ability to turn combustion into mechanical work, called thermal efficiency (Image 2.15).19 While you might expect higher pressure to mean increased knocking, the risk of preignition is low given the low load. However, at high loads, as combustion chamber temperatures rise, the same compression ratio would likely lead to autoignition. And of course, a lower CR could allow for greater boost at high loads.
Performance of Ethanol as a Transportation Fuel
Published in Charles E. Wyman, Handbook on Bioethanol, 2018
The high octane number of ethanol compared to gasoline means higher compression ratios can be used in an optimized Otto-cycle engine. Higher compression ratios result in greater engine efficiencies and higher power from a given engine size. The standard tests for research octane number and motor octane number result in an average octane number (R+M)/2, which ranges from 96 to 113. Ethanols excellent anti-knock properties lead to improved engine efficiencies [5], which range from 6% to 10%. Conversely for diesel engines, the high octane rating is correlated to a low cetane rating, which makes ethanol difficult to use in CI engines.
Emergency Generators
Published in Michael F. Hordeski, Emergency and Backup Power Sources:, 2020
Diesel engines are simple in principle, and require little routine maintenance, although this maintenance is essential to their longevity. In a diesel engine, a piston compresses air in a cylinder. The compression is measured as a compression ratio, where the cylinder volume with the piston at the bottom of the cylinder is compared with the volume when the piston is at the top of its stroke. The more air that is compressed, the hotter it becomes. At compression ratios between 16:1 and 23:1, the air temperature rises to over 1,000°F (580°C), which is well above the diesel fuel’s ignition temperature of 750°F (400°C).
Impact analysis of emulsified Calophyllum oil biodiesel B100-WIC and B50-WIC on performance and emission characteristic of a diesel engine under variation in compression ratio
Published in International Journal of Ambient Energy, 2022
Rahul Krishnaji Bawane, A. Muthuraja, Gajanan N. Shelke, Chetan Choudhary
In the present experimental work, diesel engine (Table 3) is used to study performance and emission characteristics. The engine setup (Figure 3) consists of single-cylinder, four-stroke, VCR diesel engine connected to eddy current type dynamometer for loading. The compression ratio can be changed without stopping the engine and without altering the combustion chamber geometry by specially designed tilting cylinder block arrangement. Addition to the original set CR (17:1), the effect of lowering CRs (16, 15, and 14:1) has been studies. The adjustment of CRs with the tilting head type arrangement was carried out in four steps. (Step-1; loosening Allen bolts at clamping of tilting block to some extent. Step-2; loosening the lock nut adjuster and turning the adjuster to the required CR marking on the indicator. Step-3; locking the adjuster by the lock nut. And in step-4; gently tightening all Allen bolts to clamp tilting head.)
Impact analysis of Calophyllum Inophyllum oil biodiesel on performance and emission characteristic of diesel engine under variation in compression ratio, engine load, and blend proportion
Published in International Journal of Ambient Energy, 2022
Rahul Krishnaji Bawane, A. Muthuraja, Gajanan N. Shelke, Anshul Gangele
The engine setup consists of single-cylinder, four-stroke, VCR diesel engine connected to eddy current type dynamometer for loading. The compression ratio can be changed without stopping the engine and without altering the combustion chamber geometry by specially designed tilting cylinder block arrangement. During adjusting compression ratio, tilting block Allen bolts are slightly loosened and lock nut on the adjuster is rotated so that the compression ratio is set to maximum value marked. Lock the adjuster by the lock nut, and then tighten all the Allen bolts of the tilting block. The centre distance between two pivot pins of the compression ratio indicator is measure and after changing the compression ratio, the difference can be used to know the new compression ratio.
Effects of Nano additives on performance and emission characteristics of Mentha longifolia biodiesel
Published in International Journal of Ambient Energy, 2020
S. Ganesan, S. Mahalingam, R. Arul Shyam Daniel Raj, S. Rajesh
The setup consists of single cylinder, four stroke, VCR (Variable Compression Ratio) Electric start Diesel engine connected to eddy current type dynamometer for loading (Figure 1). The compression ratio can be changed without stopping the engine and without altering the combustion chamber geometry by specially designed tilting cylinder block arrangement. Setup is provided with necessary instruments for combustion pressure and crank-angle measurements (Table 1).