For capturing and recycling of CO2 in the internal combustion engine, Rankle cycle engine can reduce the exhaust pollutants effectively under the condition of ensuring the engine thermal efficiency by using the techni...For capturing and recycling of CO2 in the internal combustion engine, Rankle cycle engine can reduce the exhaust pollutants effectively under the condition of ensuring the engine thermal efficiency by using the techniques of spraying water in the cylinder and optimizing the ignition advance angle. However, due to the water spray nozzle need to be installed on the cylinder, which increases the cylinder head design difficulty and makes the combustion conditions become more complicated. In this paper, a new method is presented to carry out the closing inlet and exhaust system for internal combustion engines. The proposed new method uses liquid oxygen to solidify part of cooled CO2 from exhaust system into dry ice and the liquid oxygen turns into gas oxygen which is sent to inlet system. The other part of CO2 is sent to inlet system and mixed with oxygen, which can reduce the oxygen-enriched combustion detonation tendency and make combustion stable. Computing grid of the IP52FMI single-cylinder four-stroke gasoline-engine is established according to the actual shape of the combustion chamber using KIVA-3V program. The effects of exhaust gas recirculation （EGR） rate are analyzed on the temperatures, the pressures and the instantaneous heat release rates when the EGR rate is more than 8%. The possibility of enclosing intake and exhaust system for engine is verified. The carbon dioxide trapping device is designed and the IP52FMI engine is transformed and the CO2 capture experiment is carried out. The experimental results show that when the EGR rate is 36% for the optimum EGR rate. When the liquid oxygen of 35.80-437.40 g is imported into the device and last 1-20 min, respectively, 21.50-701.30 g dry ice is obtained. This research proposes a new design method which can capture CO2 for vehicular internal combustion engine.展开更多
Homogeneous and stable combustion can be realized in a porous medium (PM) engine where a chemically inert PM is mounted in the combustion chamber. To understand the mechanism of the PM engine, we simulated the working...Homogeneous and stable combustion can be realized in a porous medium (PM) engine where a chemically inert PM is mounted in the combustion chamber. To understand the mechanism of the PM engine, we simulated the working process of a PM engine fueled with natural gas (CH4) using an improved version of KIVA-3V and investigated the effects of the initial PM temperature, the PM structure as well as the fuel injection timing on the compression ignition of the engine. The im- proved version of KIVA-3V was verified by simulating the experiment of Zhdanok et al. for the superadiabatic combustion of CH4-air mixtures under filtration in a packed bed. The numerical results are in good agreement with experimental data for the speed of combustion wave. Computational results for the PM engine show that the initial PM temperature is the key factor in guaranteeing the onset of com- pression ignition of the PM engine at a given compression ratio. The PM structure affects greatly both convective heat transfer between the gas and solid phase in the PM and the dispersion effect of the PM. Pore diameter of the PM is a crucial factor in determining the realization of combustion in the PM engine. Over-late fuel injec- tion timing (near TDC) cannot assure a compression ignition of the PM engine.展开更多
To improve mesh quality for KIVA-3V a method has been developed for rapid mesh generation and dynamic mesh management with moving valves for internal combustion engines. Two phases are included in rapid mesh generatio...To improve mesh quality for KIVA-3V a method has been developed for rapid mesh generation and dynamic mesh management with moving valves for internal combustion engines. Two phases are included in rapid mesh generation： the initial mesh generation and the mesh pre-treatment. In the second step （pre-treatment）, the connectivity of those cells is generated by a new algorithm added to the KIVA-3V code after the initial mesh generated. In dynamic mesh management phase, a new rezoning algorithm is developed and the basic principle is that the rezoning starts from the moving part. The movement of the adjustment is treated as an ＂earth quake wave＂ propagating to the surrounding vertexes. The amount of coordinate adjustment of the surrounding vertexes is determined by the movement of the epicenter and the distance between the vertexes and the ＂epicenter＂. Finally, a real IC engine mesh is generated and managed aceording to the new method. It gives a new theory and a new method for creating and managing the mesh in IC engine.展开更多
基金Supported by National Natural Science Foundation of China(Grant No.51176082)Importation and Development of High-Caliber Talents Project of Beijing Municipal Institutions of China(Grant No.CIT&TCD20140311)Beijing Municipal Natural Science Foundation of China(Grant No.SQKZ201510016004)
文摘For capturing and recycling of CO2 in the internal combustion engine, Rankle cycle engine can reduce the exhaust pollutants effectively under the condition of ensuring the engine thermal efficiency by using the techniques of spraying water in the cylinder and optimizing the ignition advance angle. However, due to the water spray nozzle need to be installed on the cylinder, which increases the cylinder head design difficulty and makes the combustion conditions become more complicated. In this paper, a new method is presented to carry out the closing inlet and exhaust system for internal combustion engines. The proposed new method uses liquid oxygen to solidify part of cooled CO2 from exhaust system into dry ice and the liquid oxygen turns into gas oxygen which is sent to inlet system. The other part of CO2 is sent to inlet system and mixed with oxygen, which can reduce the oxygen-enriched combustion detonation tendency and make combustion stable. Computing grid of the IP52FMI single-cylinder four-stroke gasoline-engine is established according to the actual shape of the combustion chamber using KIVA-3V program. The effects of exhaust gas recirculation （EGR） rate are analyzed on the temperatures, the pressures and the instantaneous heat release rates when the EGR rate is more than 8%. The possibility of enclosing intake and exhaust system for engine is verified. The carbon dioxide trapping device is designed and the IP52FMI engine is transformed and the CO2 capture experiment is carried out. The experimental results show that when the EGR rate is 36% for the optimum EGR rate. When the liquid oxygen of 35.80-437.40 g is imported into the device and last 1-20 min, respectively, 21.50-701.30 g dry ice is obtained. This research proposes a new design method which can capture CO2 for vehicular internal combustion engine.
基金Supported by the National Natural Science Foundation of China (Grant No. 50476073)
文摘Homogeneous and stable combustion can be realized in a porous medium (PM) engine where a chemically inert PM is mounted in the combustion chamber. To understand the mechanism of the PM engine, we simulated the working process of a PM engine fueled with natural gas (CH4) using an improved version of KIVA-3V and investigated the effects of the initial PM temperature, the PM structure as well as the fuel injection timing on the compression ignition of the engine. The im- proved version of KIVA-3V was verified by simulating the experiment of Zhdanok et al. for the superadiabatic combustion of CH4-air mixtures under filtration in a packed bed. The numerical results are in good agreement with experimental data for the speed of combustion wave. Computational results for the PM engine show that the initial PM temperature is the key factor in guaranteeing the onset of com- pression ignition of the PM engine at a given compression ratio. The PM structure affects greatly both convective heat transfer between the gas and solid phase in the PM and the dispersion effect of the PM. Pore diameter of the PM is a crucial factor in determining the realization of combustion in the PM engine. Over-late fuel injec- tion timing (near TDC) cannot assure a compression ignition of the PM engine.
基金Sponsored by the Ministerial Level Foundation (1003)Beijing Municipal Commission of Education Foundation (KM200710016013)
文摘To improve mesh quality for KIVA-3V a method has been developed for rapid mesh generation and dynamic mesh management with moving valves for internal combustion engines. Two phases are included in rapid mesh generation： the initial mesh generation and the mesh pre-treatment. In the second step （pre-treatment）, the connectivity of those cells is generated by a new algorithm added to the KIVA-3V code after the initial mesh generated. In dynamic mesh management phase, a new rezoning algorithm is developed and the basic principle is that the rezoning starts from the moving part. The movement of the adjustment is treated as an ＂earth quake wave＂ propagating to the surrounding vertexes. The amount of coordinate adjustment of the surrounding vertexes is determined by the movement of the epicenter and the distance between the vertexes and the ＂epicenter＂. Finally, a real IC engine mesh is generated and managed aceording to the new method. It gives a new theory and a new method for creating and managing the mesh in IC engine.
