Effect of Thermodynamic Irreversbility of Internal Combustion Engines on Power Output and Thermal Efficiency

2002 ◽  
Author(s):  
Kun Zi ◽  
Xuguang Lan
Keyword(s):  
Power Output ◽  
Thermal Efficiency ◽  
Internal Combustion Engines ◽  
Internal Combustion ◽  
Combustion Engines

Applying Thermodynamics in Search of Superior Engine Efficiency

2005 ◽  
Vol 127 (3) ◽  
pp. 670-675 ◽  
Author(s):  
Charles A. Amann
Keyword(s):  
Thermal Efficiency ◽  
Internal Combustion Engines ◽  
Combustion Engine ◽  
Heat Engine ◽  
Internal Combustion ◽  
Combustion Engines ◽  
Closed Cycle ◽  
Engine Efficiency ◽  
Operating Cycles ◽  
Thermodynamic Processes

Historically, a succession of thermodynamic processes has been used to idealize the operating cycles of internal combustion engines. In this study, the 256 possible combinations of four reversible processes—isentropic, isothermal, isochoric, and isobaric—are surveyed in search of cycles promising superior thermal efficiency. Regenerative cycles are excluded. The established concept of the air-standard cycle, which mimics the internal combustion engine as a closed-cycle heat engine, is used to narrow the field systematically. The approach relies primarily on graphical interpretation of approximate temperature-entropy diagrams and is qualitative only. In addition to identifying the cycles offering the greatest efficiency potential, the compromise between thermal efficiency and mean effective pressure is addressed.

scholarly journals A Review of Energy Loss Reduction Technologies for Internal Combustion Engines to Improve Brake Thermal Efficiency

Energies ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6656
Author(s):  
Zhijian Wang ◽  
Shijin Shuai ◽  
Zhijie Li ◽  
Wenbin Yu
Keyword(s):  
Energy Loss ◽  
Thermal Efficiency ◽  
Internal Combustion Engines ◽  
Fuel Efficiency ◽  
Ghg Emissions ◽  
Internal Combustion ◽  
Combustion Engines ◽  
Loss Reduction ◽  
Low Carbon ◽  
To Come

Today, the problem of energy shortage and climate change has urgently motivated the development of research engaged in improving the fuel efficiency of internal combustion engines (ICEs). Although many constructive alternatives—including battery electric vehicles (BEVs) and low-carbon fuels such as biofuels or hydrogen—are being put forward, they are starting from a very low base, and still face significant barriers. Nevertheless, 85–90% of transport energy is still expected to come from combustion engines powered by conventional liquid fuels even by 2040. Therefore, intensive passion for the improvement of engine thermal efficiency and decreasing energy loss has driven the development of reliable approaches and modelling to fully understand the underlying mechanisms. In this paper, literature surveys are presented that investigate the relative advantages of technologies mainly focused on minimizing energy loss in engine assemblies, including pistons and rings, bearings and valves, water and oil pumps, and cooling systems. Implementations of energy loss reduction concepts in advanced engines are also evaluated against expectations of meeting greenhouse gas (GHG) emissions compliance in the years to come.

scholarly journals A review of split-cycle engines

2018 ◽  
Vol 21 (6) ◽  
pp. 897-914 ◽  
Author(s):  
Joshua Finneran ◽  
Colin P Garner ◽  
Michael Bassett ◽  
Jonathan Hall
Keyword(s):  
Thermal Management ◽  
Thermal Efficiency ◽  
Internal Combustion Engines ◽  
Combustion Engine ◽  
Internal Combustion ◽  
Combustion Engines ◽  
Engine Design ◽  
Work Assessment ◽  
In Series ◽  
Management Issues

This article reviews split-cycle internal combustion engine designs. The review includes historical work, assessment of prototypes and discussion of the most recent designs. There has been an abundance of split-cycle engine designs proposed since the first in 1872. Despite this, very few prototypes exist, and no split-cycle engines are reported to be in series production. The few split-cycle prototypes that have been developed have faced practical challenges contributing to limited performance. These challenges include air flow restrictions into the expansion cylinder, late combustion, thermal management issues, and mechanical challenges with the crossover valve actuation mechanism. The main promoted advantage of split-cycle engines is the increased thermal efficiency compared to conventional internal combustion engines. However, an efficiency improvement has not thus far been demonstrated in published test data. The thermodynamic studies reviewed suggest that split-cycle engines should be more efficient than conventional four-stroke engines. Reasons why increased thermal efficiency is not realised in practice could be due to practical compromises, or due to inherent architectural split-cycle engine design limitations. It was found that the number of split-cycle engine patents has increased significantly over recent years, suggesting an increased commercial interest in the concept since the possibility of increased efficiency becomes more desirable and might outweigh the drawbacks of practical challenges.

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