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Showing papers on "Thermal efficiency published in 2015"


Journal ArticleDOI
TL;DR: In this article, the effect of 10, 20, and 50% Karanja biodiesel blends on injection rate, atomization, engine performance, emissions and combustion characteristics of common rail direct injection (CRDI) type fuel injection system were evaluated in a single cylinder research engine at different start of injection timings and constant engine speed of 1500 rpm.

268 citations


Journal ArticleDOI
TL;DR: In this paper, a single cylinder, naturally aspirated, air cooled, constant speed compression ignition engine, fuelled with two modified fuel blends, B20 (Diesel-soybean biodiesel) and D80SBD15E4S1+ alumina fuel blend, with alumina as a nanoadditive, was compared with those of neat diesel.

259 citations


Journal ArticleDOI
TL;DR: In this article, the authors proposed a combined heat and power cycle combining a gas turbine (GT) and an ORC through a single-pressure heat recovery steam generator (HRSG), and the results revealed that the increase in pressure ratio and isentropic efficiency of air compressor and gas turbine efficiency improves thermodynamic performance of the system, however, the more increase of these parameters deteriorates the total cost rates.

235 citations


Journal ArticleDOI
15 Sep 2015-Fuel
TL;DR: In this paper, the effects of pentanol addition to diesel and biodiesel fuels in different ratios on the combustion and emission of a single-cylinder direct-injection diesel engine were revealed.

232 citations


Journal ArticleDOI
TL;DR: In this paper, detailed energy and exergy analysis of four different supercritical CO2 Brayton cycle configurations were performed with and without reheat, and the effect of turbine inlet temperature and the cycle configuration on the thermal performance was analyzed.

228 citations


Journal ArticleDOI
15 Mar 2015-Energy
TL;DR: In this article, a thermodynamic comparison of five supercritical carbon dioxide Brayton cycles integrated with a solar power tower was conducted, where a heliostat field layout was generated and then optimized on an annual basis using the differential evolution method, which is an evolutionary algorithm.

222 citations


Journal ArticleDOI
TL;DR: In this article, a novel micro solar Combined Cooling, Heating, and Power (CCHP) cycle integrated with ORC for summer and winter seasons is proposed, where the thermal storage tank is installed to correct the mismatch between the supply of the solar energy and the demand of thermal source consumed by the CCHP subsystem, thus the desired system could continuously and stably operate.

217 citations


Journal ArticleDOI
TL;DR: In this paper, an investigation was conducted for the improvement of jatropha biodiesel-diesel blend with the addition of 5-10% n-butanol and diethyl ether by vol.

198 citations


Journal ArticleDOI
TL;DR: In this paper, a discussion on the application of oxygenated alternative fuels such as biodiesel, acetone-butanol-ethanol (ABE) solution and water-addition as green fuel reformulation strategies aimed at achieving engine pollutant reduction, while maintaining the integrity of the energy performance of the diesel engine.

197 citations


Journal ArticleDOI
15 Mar 2015-Energy
TL;DR: In this paper, two separated ORC apparatuses for the waste heat from both the jacket cooling water and the engine exhaust gas are designed as the traditional recovery system, and the maximum net power output is chosen as the evaluation criterion to select the suitable working fluid and define the optimal system parameters.

188 citations


Journal ArticleDOI
TL;DR: In this paper, a thermodynamic analysis is presented based on traditional cycle calculations coupled with a Schumann-style model of the packed beds, and results of an optimisation study are then given in the form of trade-off surfaces for roundtrip efficiency, energy density and power density.

Journal ArticleDOI
TL;DR: In this paper, the performance of a flat plate solar collector with SiO2/ethylene glycol (EG) nanofluid with volume fractions up to 1% was investigated.

Journal ArticleDOI
TL;DR: In this article, a small parabolic trough collector model is designed and simulated for different operating conditions to predict the efficiency of this model and to analyze the heat transfer phenomena that take place.

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.

Journal ArticleDOI
TL;DR: In this article, the authors investigated the thermodynamic and economic performances optimization for an ORC system recovering the waste heat of exhaust gas from a large marine diesel engine of the merchant ship.

Journal ArticleDOI
TL;DR: In this article, an experimental investigation was carried out to assess the effects of using plastic oil in a DI diesel engine and the results indicated that the thermal efficiency of all blends and neat plastic oil is lower than diesel at all loading conditions.

Journal ArticleDOI
TL;DR: This work quantifies the residual heat generated by U.S. thermal power plants and assesses the intermittency and transport issues that must be considered when planning to utilize this heat, and characterize the temperature, spatial distribution, and temporal availability of this residual heat at the plant level.
Abstract: Secondary application of unconverted heat produced during electric power generation has the potential to improve the life-cycle fuel efficiency of the electric power industry and the sectors it serves. This work quantifies the residual heat (also known as waste heat) generated by U.S. thermal power plants and assesses the intermittency and transport issues that must be considered when planning to utilize this heat. Combining Energy Information Administration plant-level data with literature-reported process efficiency data, we develop estimates of the unconverted heat flux from individual U.S. thermal power plants in 2012. Together these power plants discharged an estimated 18.9 billion GJth of residual heat in 2012, 4% of which was discharged at temperatures greater than 90 °C. We also characterize the temperature, spatial distribution, and temporal availability of this residual heat at the plant level and model the implications for the technical and economic feasibility of its end use. Increased impleme...

Journal ArticleDOI
TL;DR: In this article, a 100kW regenerative Brayton heat engine driven by the hybrid of fossil fuel and solar energy was considered for optimization based on multiple criteria, such as power output, thermal efficiency and dimensionless thermo-economic performance.

Journal ArticleDOI
TL;DR: In this article, an experimental investigation of a small scale (1kW range) organic Rankine cycle system for net electrical power output ability, using low-grade waste heat from steam.

Journal ArticleDOI
TL;DR: In this article, a single cylinder, common rail direct injection (CRDI) system assisted diesel engine using diesel with 25 percentage of zizipus jujube methyl ester blended fuel (ZJME25) was evaluated.
Abstract: Experiments were conducted to determine engine performance, exhaust emissions and combustion characteristics of a single cylinder, common rail direct injection (CRDI) system assisted diesel engine using diesel with 25 percentage of zizipus jujube methyl ester blended fuel (ZJME25). Along with this ZJME25 aluminium oxide nanoparticles were added as additive in mass fractions of 25 ppm (AONP 25) and 50 ppm (AONP 50) with the help of a mechanical Homogenizer and an ultrasonicator. It was observed that aluminium oxide nanoparticles blended fuel exhibits a significant reduction in specific fuel consumption and exhaust emissions at all operating loads. At the full load, the magnitude of HC and smoke emission for the ZJME25 before the addition of aluminium oxide nanoparticles was 13.459 g/kW h and 79 HSU, whereas it was 8.599 g/kW h and 49 HSU for the AONP 50 blended ZJME25 fuel respectively. The results also showed a considerable enhancement in brake thermal efficiency and heat release rate due to the influence of aluminium oxide nanoparticles addition in biodiesel–diesel blend.

Journal ArticleDOI
TL;DR: In this article, the principles, transfer mechanism and thermal efficiency characterization of the Membrane Distillation (MD) process were introduced and various factors affecting the thermal efficiency were analyzed.

Journal ArticleDOI
TL;DR: In this paper, the effects of thermo-physical properties of short Single Wall Carbon Nanotubes (SWCNTs) suspended in water was investigated in order to enhance thermal efficiency of a flat plate solar collector.

Journal ArticleDOI
Wang Pan1, Chunde Yao1, Guopeng Han1, Hongyuan Wei1, Quangang Wang1 
15 Dec 2015-Fuel
TL;DR: In this article, a parametric study concerned with methanol mass fraction and intake air temperature was conducted to better understand how the intake air and methanoline fumigation affect the performance and emissions of diesel engine.

Journal ArticleDOI
TL;DR: In this article, an exergy analysis of a DI diesel engine running on several biodiesel/diesel blends (B5) containing various quantities of expanded polystyrene (EPS) was carried out.

Journal ArticleDOI
01 Feb 2015-Energy
TL;DR: In this article, the authors reveal the combustion and emission characteristics of pentanol in a single-cylinder direct-injection diesel engine and show that NO x and soot emissions decrease significantly for pentanol with comparable efficiencies under single injection strategy without EGR (exhaust gas recirculation).

Journal ArticleDOI
TL;DR: In this paper, a dual-loop organic Rankine cycle (ORC) system is designed to recover the waste heat of a diesel engine, where water is selected as the working fluid for the HT loop and wet steam expansion, which can be implemented through screw expanders, is exploited.

Journal ArticleDOI
TL;DR: In this article, the influence of compression ratio on the performance, combustion and emission characteristics of a single cylinder four stroke direct injection naturally aspirated diesel engine was investigated and varied by altering the dimensions of piston bowl by keeping the standard stroke volume.
Abstract: The present work investigates the influence of compression ratio on the performance, combustion and emission characteristics of a single cylinder four stroke direct injections naturally aspirated diesel engine. Compression ratios such as 17.5:1, 18.5:1 and 19.5:1 were considered and varied by altering the dimensions of piston bowl by keeping the standard stroke volume. Tests were performed with five different blends of ethanol [E0, E10, E20, E30 and E40]. To maintain homogeneity and to prevent the phase separation, 1% of Ethyl Acetate plus 1% diethyl carbonate are added to ethanol diesel blend. The brake thermal efficiency found to increase at full load with higher percentage of ethanol at maximum compression ratio. The increase in compression ratio and ethanol blended fuel improves combustion and improves the performance of engine. Further there is a significant decrease in hydrocarbon (HC), Carbon monoxide (CO) and smoke emissions however there is an increase in Nitrogen oxides (NOx).

Journal ArticleDOI
15 Mar 2015-Energy
TL;DR: In this paper, a finite element numerical model is developed for the accurate 3D analysis of transient diffusive and convective heat exchange phenomena taking place in geothermal structures, which is validated by reproducing both the outcome of a thermal response test carried out on a test pile, and the average response of the linear heat source analytical solution.

Journal ArticleDOI
TL;DR: In this paper, an exergoeconomic and enviroeconomic analysis of partially covered photovoltaic thermal (PVT) flat plate collector (FPC) integrated solar distillation system known as PVT-FPC active solar dis-tillation system is presented.

Journal ArticleDOI
TL;DR: In this article, the effect of bio-diesel on a diesel engine when compared to diesel and evolves conclusions with respect to performance and emissions are evaluated, even though the performance reduces slightly when the engine is fueled with biodiesel, significant changes in the combustion parameters observed in case of biodiesel blends are significant to note.