Energy valorization of organic waste material is nowadays an assessed practice of circular economy.Combined heat and power(CHP)technologies based on biomass gasification represent viable substitutes to traditional ene...Energy valorization of organic waste material is nowadays an assessed practice of circular economy.Combined heat and power(CHP)technologies based on biomass gasification represent viable substitutes to traditional energy conversion units based on combustion,whose need has recently experienced a huge growth,due to the increasing concerns about the release of greenhouse gases(GHGs)emissions and the related effects on climate changes.At present,only a few solutions have yet achieved a level of full development for commercialization.One of them is the system developed by CMD,the CMD ECO20,made of a gasifier,a syngas cleaning system and a spark ignition internal combustion engine working as a co-generator.In the present work,a numerical model is developed to study this system into detail and search for optimal controlling parameters.The simulation relies on a combined use of the Thermoflex?environment and a proper one-dimensional(1D)model of the engine module built within GT-Suite?.An original contribution is given to the turbulent combustion model that accounts for the laminar flame speed of the specific syngas.The numerical model,that covers the entire biomass-to-energy conversion process,is validated under real operative conditions.The final purpose of the work is the optimization of input parameters,as the initial biomass moisture content,the equivalence ratio at the gasifier or the timing of spark advance,to maximize the system electrical energy output.展开更多
A numerical simulation of a single cylinder research diesel engine fuelled by natural gas and diesel oil in dual fuel mode was conducted to test the reaction mechanism presented by Li and Williams in Ref.[1]for methan...A numerical simulation of a single cylinder research diesel engine fuelled by natural gas and diesel oil in dual fuel mode was conducted to test the reaction mechanism presented by Li and Williams in Ref.[1]for methane ignition.The mechanism made of only 9 reactions can represent a good compromise between reduction of computational time and accuracy of results.Simulations reproduce test cases previously carried out experimentally and numerically with a simpler kinetic mechanism at three different premixed ratios(10%,15% and 22%).Finally,a last case characterized by a supply of methane consistent with the typical load levels for this kind of engines(80%),was investigated only numerically.All the simulations were performed with the KIVA-3V solver on a geometry which includes open valve periods,intake and exhaust ducts.Through a comparison between experimental and numerical results,a calibration of the model has been performed and a quite good fitting of the models has been achieved.展开更多
文摘Energy valorization of organic waste material is nowadays an assessed practice of circular economy.Combined heat and power(CHP)technologies based on biomass gasification represent viable substitutes to traditional energy conversion units based on combustion,whose need has recently experienced a huge growth,due to the increasing concerns about the release of greenhouse gases(GHGs)emissions and the related effects on climate changes.At present,only a few solutions have yet achieved a level of full development for commercialization.One of them is the system developed by CMD,the CMD ECO20,made of a gasifier,a syngas cleaning system and a spark ignition internal combustion engine working as a co-generator.In the present work,a numerical model is developed to study this system into detail and search for optimal controlling parameters.The simulation relies on a combined use of the Thermoflex?environment and a proper one-dimensional(1D)model of the engine module built within GT-Suite?.An original contribution is given to the turbulent combustion model that accounts for the laminar flame speed of the specific syngas.The numerical model,that covers the entire biomass-to-energy conversion process,is validated under real operative conditions.The final purpose of the work is the optimization of input parameters,as the initial biomass moisture content,the equivalence ratio at the gasifier or the timing of spark advance,to maximize the system electrical energy output.
文摘A numerical simulation of a single cylinder research diesel engine fuelled by natural gas and diesel oil in dual fuel mode was conducted to test the reaction mechanism presented by Li and Williams in Ref.[1]for methane ignition.The mechanism made of only 9 reactions can represent a good compromise between reduction of computational time and accuracy of results.Simulations reproduce test cases previously carried out experimentally and numerically with a simpler kinetic mechanism at three different premixed ratios(10%,15% and 22%).Finally,a last case characterized by a supply of methane consistent with the typical load levels for this kind of engines(80%),was investigated only numerically.All the simulations were performed with the KIVA-3V solver on a geometry which includes open valve periods,intake and exhaust ducts.Through a comparison between experimental and numerical results,a calibration of the model has been performed and a quite good fitting of the models has been achieved.
