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Thermal efficiency

About: Thermal efficiency is a research topic. Over the lifetime, 20911 publications have been published within this topic receiving 302373 citations. The topic is also known as: thermodynamic efficiency & efficiency.


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Journal ArticleDOI
TL;DR: In this article, the performance of an ammonia-water Rankine cycle with a positive displacement expander was evaluated and compared to four organic Rankine cycles and a Kalina-type cycle and showed that, in order to determine the best cycle configuration and parameters, energy efficiency must be used only in conjunction with the amount of the heat recovered from the source.

152 citations

Proceedings ArticleDOI
TL;DR: In this article, the trade-off between inlet air temperature and Compression Ratio (CR) was evaluated in a homogeneous charge compression ignition (HCCI) engine with variable compression ratio (VCR).
Abstract: Combustion phasing in a Homogeneous Charge Compression Ignition (HCCI) engine can be achieved by affecting the time history of pressure and temperature in the cylinder. The most common way has been to control the inlet air temperature and thereby the temperature in the cylinder at the end of the compression stroke. However this is a slow parameter to control, especially cycle to cycle. A multi- cylinder engine using Variable Compression Ratio (VCR) for controlling the compression temperature and consequently the combustion phasing is used in the experiments. Operating range in terms of speed and load is investigated in naturally aspirated mode. Trade-off between inlet air temperature and Compression Ratio (CR) is evaluated. Primary reference fuels, isooctane/n-heptane, are used during the tests. High-speed HCCI operation up to 5000 rpm is possible with a fuel corresponding to RON 60. The effect of octane number with and without exhaust cam phasing is also investigated. Brake thermal efficiency of 33% at a maximum load of 4.4 bar BMEP for 2000 rpm is achieved. (Less)

152 citations

Journal ArticleDOI
TL;DR: In this article, the optimization of a combined cycle power plant describing and comparing four different gas turbine cycles: simple cycle, inter-cooled cycle, reheated cycle and intercooled-and-reheated cycle is presented.

152 citations

Journal ArticleDOI
Wei Yanju1, Liu Shenghua1, Li Hongsong1, Yang Rui1, Liu Jie1, Wang Ying1 
TL;DR: In this paper, the effects of different methanol/gasoline ratios on engine power, thermal efficiency, and emissions, especially the exhaust methanols emission, were investigated using three-cylinder, port fuel injection engine.
Abstract: Three typical methanol−gasoline blends M10, M20, and M85 containing 10%, 20%, and 85% of methanol by volume, respectively, were used to investigate the effects of different methanol/gasoline ratios on engine power, thermal efficiency, and emissions, especially the exhaust methanol emission. A three-cylinder, port fuel injection engine was applied. Experimental results show that the engine power/torque ratio under the wide open throttle condition mainly depends on the amount of heat delivered to the engine. The addition of methanol significantly improves the brake thermal efficiency, while the methanol/gasoline ratio has a slight effect on it. Engine out CO and NOx emissions decrease with the increase of the methanol/gasoline ratio. The use of M85 leads to a reduction of CO and NOx by about 25% and 80%, respectively. A gas chromatograph is calibrated and used to measure the methanol emission. Measurement indicates that the addition of methanol in gasoline results in an increase of the unburnt CH3OH emissio...

151 citations

Journal ArticleDOI
TL;DR: In this paper, the effects of natural gas injection timing on the combustion and emissions performance under different pilot injection pressure and timing at low load conditions were investigated for a common rail diesel research engine converted to operate in dual-fuel mode.

150 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
2023418
2022839
20211,279
20201,203
20191,197
20181,145