The Experts below are selected from a list of 213 Experts worldwide ranked by ideXlab platform
Mehdi Ali Ehyaei - One of the best experts on this subject based on the ideXlab platform.
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Feasibility study of using organic Rankine and Reciprocating Engine systems for supplying demand loads of a residential building
Advances in Building Energy Research, 2017Co-Authors: Moein Yousefi, Mehdi Ali EhyaeiAbstract:ABSTRACTIn this paper, the potentials of the combined use of organic Rankine cycle (ORC) and Reciprocating Engine for supplying electric power, as well as heating and cooling loads of a residential building in Tehran, are discussed. The studied building is a 10-floor building with a total area of 8000 m2. The type of Reciprocating Engine and ORC was selected based on CHP (cooling, heating and power) data and consequently, the number of required Engines and ORC systems was calculated. It was concluded that, at most, three Reciprocating Engines with a rated power of 145 kW and three ORCs with a nominal power of 35 kW should be used to meet all loads of studied building. The cost of electricity is about 0.18 (US$/kWh). This system is not economical in comparison with electricity cost incurred by IC (internal combustion) Engine employing natural gas as a fuel, but it is more economical than using micro gas turbine.
Volker Sick - One of the best experts on this subject based on the ideXlab platform.
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experimental and numerical investigation of temperature fluctuations in the near wall region of an optical Reciprocating Engine
Proceedings of the Combustion Institute, 2021Co-Authors: Mohammad K Alzuabi, Volker SickAbstract:Abstract Accurate prediction of in-cylinder heat transfer processes within internal combustion Engines (ICEs) requires a comprehensive understanding of the boundary layer effects in the near-wall region (NWR). This study investigates near-wall temperature fluctuations of an optical Reciprocating Engine using a combined approach of planar laser-induced fluorescence (PLIF) thermometry and numerical conjugate heat transfer modeling. Single-line excitation of toluene and subsequent one-color emission detection is employed for PLIF thermometry, while large-eddy simulations (LES) using commercial CFD software (CONVERGE v2.4.18) is utilized for modeling. The PLIF signal is calibrated to predicted in-cylinder temperatures from a GT-POWER simulation, and precision uncertainty of temperature is found to be ±1.5 K within the calibration region. Near-wall temperature fluctuations are determined about the multi-cycle mean, and the development of thermal stratification is captured in the NWR under motored and fired conditions during the compression stroke. Regions of the largest cycle-to-cycle temperature fluctuations are identified closer to the in-cylinder head surface indicating the unsteadiness of the thermal boundary layer. Analysis includes an assessment of cyclic variability of near-wall temperature fluctuation, and the effects of compression on temperature fluctuations. Additionally, thermal stratification is found to be similar under motored and fired conditions before ignition timing. Lastly, spatial correlation analysis of temperature fluctuations is performed in the wall-normal direction, and it reveals higher correlations under fired conditions. Spatial correlations experience an initial drop outside of the buffer layer in the NWR, and the location of the drop is well captured in the simulations. Analysis of fluctuating temperatures needs to be extended to fluctuations about the spatial average temperature which directly affects the spatial thermal gradients relevant to Engine heat transfer.
H S Mukunda - One of the best experts on this subject based on the ideXlab platform.
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biomass derived producer gas as a Reciprocating Engine fuel an experimental analysis
Biomass & Bioenergy, 2001Co-Authors: G Sridhar, P J Paul, H S MukundaAbstract:This paper uncovers some of the misconceptions associated with the usage of producer gas, a lower calorific gas as a Reciprocating Engine fuel. This paper particularly addresses the use of producer gas in Reciprocating Engines at high compression ratio (17 : 1), which hitherto had been restricted to lower compression ratio (up to 12 : 1). This restriction in compression ratio has been mainly attributed to the auto-ignition tendency of the fuel, which appears to be simply a matter of presumption rather than fact. The current work clearly indicates the breakdown of this compression ratio barrier and it is shown that the Engine runs smoothly at compression ratio of 17 : 1 without any tendency of auto-ignition. Experiments have been conducted on multi-cylinder spark ignition Engine modified from a production diesel Engine at varying compression ratios from 11.5 : 1 to 17 : 1 by retaining the combustion chamber design. As expected, working at a higher compression ratio turned out to be more efficient and also yielded higher brake power. A maximum brake power of 17.5 kWe was obtained at an overall efficiency of 21% at the highest compression ratio. The maximum de-rating of power in gas mode was 16% as compared to the normal diesel mode of operation at comparable compression ratio, whereas, the overall efficiency declined by 32.5%. A careful analysis of energy balance revealed excess energy loss to the coolant due to the existing combustion chamber design. Addressing the combustion chamber design for producer gas fuel should form a part of future work in improving the overall efficiency.
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Biomass derived producer gas as a Reciprocating Engine fuel—an experimental analysis
Biomass and Bioenergy, 2001Co-Authors: G Sridhar, P J Paul, H S MukundaAbstract:This paper uncovers some of the misconceptions associated with the usage of producer gas, a lower calorific gas as a Reciprocating Engine fuel. This paper particularly addresses the use of producer gas in Reciprocating Engines at high compression ratio (17 : 1), which hitherto had been restricted to lower compression ratio (up to 12 : 1). This restriction in compression ratio has been mainly attributed to the auto-ignition tendency of the fuel, which appears to be simply a matter of presumption rather than fact. The current work clearly indicates the breakdown of this compression ratio barrier and it is shown that the Engine runs smoothly at compression ratio of 17 : 1 without any tendency of auto-ignition. Experiments have been conducted on multi-cylinder spark ignition Engine modified from a production diesel Engine at varying compression ratios from 11.5 : 1 to 17 : 1 by retaining the combustion chamber design. As expected, working at a higher compression ratio turned out to be more efficient and also yielded higher brake power. A maximum brake power of 17.5 kWe was obtained at an overall efficiency of 21% at the highest compression ratio. The maximum de-rating of power in gas mode was 16% as compared to the normal diesel mode of operation at comparable compression ratio, whereas, the overall efficiency declined by 32.5%. A careful analysis of energy balance revealed excess energy loss to the coolant due to the existing combustion chamber design. Addressing the combustion chamber design for producer gas fuel should form a part of future work in improving the overall efficiency.
Moein Yousefi - One of the best experts on this subject based on the ideXlab platform.
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Feasibility study of using organic Rankine and Reciprocating Engine systems for supplying demand loads of a residential building
Advances in Building Energy Research, 2017Co-Authors: Moein Yousefi, Mehdi Ali EhyaeiAbstract:ABSTRACTIn this paper, the potentials of the combined use of organic Rankine cycle (ORC) and Reciprocating Engine for supplying electric power, as well as heating and cooling loads of a residential building in Tehran, are discussed. The studied building is a 10-floor building with a total area of 8000 m2. The type of Reciprocating Engine and ORC was selected based on CHP (cooling, heating and power) data and consequently, the number of required Engines and ORC systems was calculated. It was concluded that, at most, three Reciprocating Engines with a rated power of 145 kW and three ORCs with a nominal power of 35 kW should be used to meet all loads of studied building. The cost of electricity is about 0.18 (US$/kWh). This system is not economical in comparison with electricity cost incurred by IC (internal combustion) Engine employing natural gas as a fuel, but it is more economical than using micro gas turbine.
A. D. Kiverin - One of the best experts on this subject based on the ideXlab platform.
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Combustion of hydrogen-based mixtures in gas-fueled Reciprocating Engines
Thermal Engineering, 2015Co-Authors: A. E. Smygalina, V. M. Zaitchenko, M. F. Ivanov, A. D. KiverinAbstract:The research is devoted to the possibility for application of hydrogen accumulated from renewable energy sources as a fuel for a Reciprocating Engine, which serves as an electrical generator drive. Hydrogen combustion in the chamber of a Reciprocating Engine, as a rule, occurs in a detonation mode. In order to obtain less hard modes, the present research proposes the usage of steam additions to hydrogen–air mixture or lean hydrogen–air mixtures. Mathematical simulation is used for investigation of combustion of mentioned mixtures in the combustion chamber of a Reciprocating Engine with a spark-plug ignition. The comparison of the usage of hydrogen–steam–air mixtures and lean hydrogen–air mixtures as fuels is given. The dependence of arising combustion modes and its quantitative characteristics on hydrogen content in combustible composition is investigated. The analysis of optimal combustion is presented, which is based on the consideration of two parameters: peak pressure in one cycle and the crankshaft angle corresponding to the achievement of the peak pressure.
