Improving the specific,technical,economic,and environmental characteristics of piston engines(ICE)operating on alternative gaseous fuels is a pressing task for the energy and mechanical engineering industries.The aim ...Improving the specific,technical,economic,and environmental characteristics of piston engines(ICE)operating on alternative gaseous fuels is a pressing task for the energy and mechanical engineering industries.The aim of the study was to optimize the parameters of the ICE working cycle after replacing the base fuel(propane-butane blend)with syngas from wood sawdust to improve its technical and economic performance based on mathematical modeling.The modeling results were verified through experimental studies(differences for key parameters did not exceed 4.0%).The object of the study was an electric generator based on a single-cylinder spark ignition engine with a power of 1 kW.The article describes the main approaches to creating a mathematical model of the engine working cycle,a test bench for modeling verification,physicochemical properties of the base fuel(propane-butane blend),and laboratory syngas.It was shown that replacing the fuel from a propane-butane blend to laboratory syngas caused a decrease in engine efficiency to 33%(the efficiency of the base ICE was 0.179 vs.the efficiency of 0.119 for the converted ICE for the 0.59 kW power mode).Engine efficiency was chosen as the key criterion for optimizing the working cycle.As a result of optimization,the efficiency of the converted syngas engine was 6.1%higher than that of the base engine running on the propane-butane blend,and the power drop did not exceed 8.0%.Thus,careful fine-tuning of the working cycle parameters allows increasing the technical and economic characteristics of the syngas engine to the level of ICEs running on traditional types of fuel.展开更多
Industry and energy continue to require piston engines(PICE)at a high level worldwide.Therefore,science and technology must urgently work on improving the PICE working cycle.Improving the quality of the intake process...Industry and energy continue to require piston engines(PICE)at a high level worldwide.Therefore,science and technology must urgently work on improving the PICE working cycle.Improving the quality of the intake process of theworking fluid into the cylinder is one of the most effective ways to improve the operational performance of PICE.The purpose of the study was to assess the impact of various cylinder head(CylH)designs on the gas-dynamic and heat-exchange qualities of air flows within an engine model’s intake system.Three different CylH designs were studied:the basic configuration and upgraded cylinder heads with a square valve and a square valve port.These designs are innovative.Laboratory conditions were used to conduct the studies for stationary air flow.The experiments covered the range of Reynolds numbers from 8500 to 96,000.The intake system’s gas dynamics and heat transfer were determined using the thermal anemometry method,which was based on constant-temperature hot-wire anemometers.It has been established that the use of upgraded CylHs causes an increase in the turbulence number of flow by an average of 13.5%.Additionally,itwas found that the increase in the turbulence number of flowin the cylinder is about 19%when installing new CylH designs.It was shown that therewas an increase in the heat transfer coefficient in the intake pipe by 10%–40%when installing modernized CylH designs in the intake system.The article focused on the problems of increasing the turbulence level and intensifying the heat transfer of stationary air flow in the intake system,specifically in PICEs.The study’s findings are novel in the areas of applied gas dynamics and PICEs.展开更多
Experimental research into the boiling-up of a free jet of superheated water discharging through a short cylindrical nozzle with sharp inlet and outlet edges into the atmosphere has been carried out.The change in the ...Experimental research into the boiling-up of a free jet of superheated water discharging through a short cylindrical nozzle with sharp inlet and outlet edges into the atmosphere has been carried out.The change in the shape of a liquid jet has been traced through changes in thermodynamic parameters(temperature,pressure)along the saturation line in both the visible range and the infrared spectrum.The flow shapes corresponding to various modes of boiling-up have been identified.With thermal-imaging diagnostics,heterogeneities in the spray plume of a superheated liquid jet have been recorded and temperature distributions have been obtained in various sections of a boiling-up flow.The maximum temperature in the flare of a boiling-up jet has been determined at different distances from the short nozzle’s exit edge.展开更多
Heat engines based on reciprocating machines remain in demand as energy converters in a variety of industries around the world.The aim of the study was to evaluate the gas-dynamic,consumable and heat exchange characte...Heat engines based on reciprocating machines remain in demand as energy converters in a variety of industries around the world.The aim of the study was to evaluate the gas-dynamic,consumable and heat exchange characteristics of non-stationary air flows in a supply system with transverse profiling of valve channels based on experimental studies.Valve channels with cross sections in the form of a circle,square and triangle were used to control the consumable and heat exchange characteristics of the flows in the supply system of the reciprocatingengine model.The article presents data on changes in local velocity,volumetric airflow and instantaneous heat transfer coefficient of non-stationary airflow in supply systems with different valve channel designs.A spectral analysis of the pulsations of the local heat transfer coefficient was also performed.The Nusselt number was calculated for the studied supply systems.The figured valve channels lead to an increase in the volumetric airflow through the supply systemupto32%comparedwiththe basic configuration.The useof a square valve channel leads to suppression of heat transfer(drop is about 15%)compared to the basic supply system,and the use of a triangular valve channel causes an intensification of heat transfer(growth is about 17.5%).The obtained data can be useful for refining mathematical models,adjusting machine learning algorithms,and improving design methods for supply systems of reciprocating machines to improve their technical,economic,and environmental characteristics.展开更多
基金the Ministry of Science and Higher Education of the Russian Federation(Ural Federal University Program of Development within the Priority-2030 Program)is gratefully acknowledged.
文摘Improving the specific,technical,economic,and environmental characteristics of piston engines(ICE)operating on alternative gaseous fuels is a pressing task for the energy and mechanical engineering industries.The aim of the study was to optimize the parameters of the ICE working cycle after replacing the base fuel(propane-butane blend)with syngas from wood sawdust to improve its technical and economic performance based on mathematical modeling.The modeling results were verified through experimental studies(differences for key parameters did not exceed 4.0%).The object of the study was an electric generator based on a single-cylinder spark ignition engine with a power of 1 kW.The article describes the main approaches to creating a mathematical model of the engine working cycle,a test bench for modeling verification,physicochemical properties of the base fuel(propane-butane blend),and laboratory syngas.It was shown that replacing the fuel from a propane-butane blend to laboratory syngas caused a decrease in engine efficiency to 33%(the efficiency of the base ICE was 0.179 vs.the efficiency of 0.119 for the converted ICE for the 0.59 kW power mode).Engine efficiency was chosen as the key criterion for optimizing the working cycle.As a result of optimization,the efficiency of the converted syngas engine was 6.1%higher than that of the base engine running on the propane-butane blend,and the power drop did not exceed 8.0%.Thus,careful fine-tuning of the working cycle parameters allows increasing the technical and economic characteristics of the syngas engine to the level of ICEs running on traditional types of fuel.
文摘Industry and energy continue to require piston engines(PICE)at a high level worldwide.Therefore,science and technology must urgently work on improving the PICE working cycle.Improving the quality of the intake process of theworking fluid into the cylinder is one of the most effective ways to improve the operational performance of PICE.The purpose of the study was to assess the impact of various cylinder head(CylH)designs on the gas-dynamic and heat-exchange qualities of air flows within an engine model’s intake system.Three different CylH designs were studied:the basic configuration and upgraded cylinder heads with a square valve and a square valve port.These designs are innovative.Laboratory conditions were used to conduct the studies for stationary air flow.The experiments covered the range of Reynolds numbers from 8500 to 96,000.The intake system’s gas dynamics and heat transfer were determined using the thermal anemometry method,which was based on constant-temperature hot-wire anemometers.It has been established that the use of upgraded CylHs causes an increase in the turbulence number of flow by an average of 13.5%.Additionally,itwas found that the increase in the turbulence number of flowin the cylinder is about 19%when installing new CylH designs.It was shown that therewas an increase in the heat transfer coefficient in the intake pipe by 10%–40%when installing modernized CylH designs in the intake system.The article focused on the problems of increasing the turbulence level and intensifying the heat transfer of stationary air flow in the intake system,specifically in PICEs.The study’s findings are novel in the areas of applied gas dynamics and PICEs.
文摘Experimental research into the boiling-up of a free jet of superheated water discharging through a short cylindrical nozzle with sharp inlet and outlet edges into the atmosphere has been carried out.The change in the shape of a liquid jet has been traced through changes in thermodynamic parameters(temperature,pressure)along the saturation line in both the visible range and the infrared spectrum.The flow shapes corresponding to various modes of boiling-up have been identified.With thermal-imaging diagnostics,heterogeneities in the spray plume of a superheated liquid jet have been recorded and temperature distributions have been obtained in various sections of a boiling-up flow.The maximum temperature in the flare of a boiling-up jet has been determined at different distances from the short nozzle’s exit edge.
基金supported by the Russian Science Foundation(Grant No.23-29-00022).
文摘Heat engines based on reciprocating machines remain in demand as energy converters in a variety of industries around the world.The aim of the study was to evaluate the gas-dynamic,consumable and heat exchange characteristics of non-stationary air flows in a supply system with transverse profiling of valve channels based on experimental studies.Valve channels with cross sections in the form of a circle,square and triangle were used to control the consumable and heat exchange characteristics of the flows in the supply system of the reciprocatingengine model.The article presents data on changes in local velocity,volumetric airflow and instantaneous heat transfer coefficient of non-stationary airflow in supply systems with different valve channel designs.A spectral analysis of the pulsations of the local heat transfer coefficient was also performed.The Nusselt number was calculated for the studied supply systems.The figured valve channels lead to an increase in the volumetric airflow through the supply systemupto32%comparedwiththe basic configuration.The useof a square valve channel leads to suppression of heat transfer(drop is about 15%)compared to the basic supply system,and the use of a triangular valve channel causes an intensification of heat transfer(growth is about 17.5%).The obtained data can be useful for refining mathematical models,adjusting machine learning algorithms,and improving design methods for supply systems of reciprocating machines to improve their technical,economic,and environmental characteristics.
