This paper aims to design a special exchanger to recover the exhaust gas heat of marine diesel engines used in small and medium-sized fishing vessels,which can then be used to heat water up to 55°C–85°C for...This paper aims to design a special exchanger to recover the exhaust gas heat of marine diesel engines used in small and medium-sized fishing vessels,which can then be used to heat water up to 55°C–85°C for membrane desalination devices to produce fresh water.A new exhaust-gas heat exchanger of fins and tube,with a reinforced heat transfer tube section,unequal spacing fins,a mixing zone between the fin groups and four routes tube bundle,was designed.Numerical simulations were also used to provide reference information for structural design.Experiments were carried out for exhaust gas waste heat recovery from a marine diesel engine in an engine test bench utilizing the heat exchanger.The experimental results show that the difference between heat absorption by water and heat reduction of exhaust gas is less than 6.5%.After the water flow rate was adjusted,the exhaust gas waste heat recovery efficiency was higher than 70%,and the exhaust-gas heat exchanger’s outlet water temperature was 55°C–85°C at different engine loads.This means that the heat recovery from the exhaust gas of a marine diesel engine meets the requirement to drive a membrane desalination device to produce fresh water for fishers working in small and medium-sized fishing vessels.展开更多
A hardware-in-the-loop simulating platform is developed to avoid designing defects caused by the complicated logical structure and multiple-functional buildup of the dectronic control unit（ECU）in modem diesel engine...A hardware-in-the-loop simulating platform is developed to avoid designing defects caused by the complicated logical structure and multiple-functional buildup of the dectronic control unit（ECU）in modem diesel engines, and to diminish potential damages on components or human exposure to dangers in R＆D en- deavor. This plat-form consists of a computer installed with software Matlab/Simulink/RTW and dSPACE/ ControlDesk; a diesel engine ECU, and a dSPACE autobox which runs a real-time diesel engine model. A typical model of diesel engine with turbocharger and intercooler is presented. Based on this model our research is carried out with a real ECU to test its software control strategies. Results show that by using the diesel engine model downloaded inside, the hardware-in-the-loop platform can simulate diesel engine＇s working conditions and generate all kinds of sensor signals which ECU needs on a real-time basis. So the ECU control strategies can be validated and relevant parameters roughly calibrated.展开更多
为了研究不同比例的异戊醇/柴油混合燃料在4190Z L C-2型船用中速柴油机中的燃烧和排放特性,运用AVL_FIRE仿真软件建立柴油机燃烧室模型,并通过台架实验验证其仿真模型的准确性。在仿真软件中通过调整异戊醇在柴油中的掺混比来研究混合...为了研究不同比例的异戊醇/柴油混合燃料在4190Z L C-2型船用中速柴油机中的燃烧和排放特性,运用AVL_FIRE仿真软件建立柴油机燃烧室模型,并通过台架实验验证其仿真模型的准确性。在仿真软件中通过调整异戊醇在柴油中的掺混比来研究混合燃料对柴油机燃烧和排放性能的影响。结果表明:掺混异戊醇有助于改变NO的生成规律,使NO在速燃期的生成量上升,在缓燃期与后燃期的生成量减少,并且总体生成的NO质量分数降低;随着异戊醇掺混比的上升,CO最终生成质量分数下降,Soot最终生成质量分数上升,同时生成的Soot质量分数峰值降低,在缓燃期的氧化速率增快,并因为较快的耗氧量使得最终生成的Soot质量分数比纯柴油的高。展开更多
In comparison to onshore facilities,ships,and their machinery are subjected to challenging external influences such as rolling,vibration,and continually changing air&cooling water temperatures in the marine enviro...In comparison to onshore facilities,ships,and their machinery are subjected to challenging external influences such as rolling,vibration,and continually changing air&cooling water temperatures in the marine environment.However,these factors are typically neglected,or their consequences are deemed to have little effect on machinery,the environment,or human life.In this study,seasonal air&seawater temperature effects on marine diesel engine performance parameters and emissions are investigated by using a full-mission engine room simulator.A tanker ship two-stroke main engine MAN B&W 6S50 MC-C with a power output of 8600 kW is employed during the simulation process.Furthermore,due to its diverse risks,the Marmara Region is chosen as the application area for real-time average temperature data.Based on the research findings,even minor variations in seasonal temperatures have a significant influence on certain key parameters of a ship’s main engine including scavenge pressure,exhaust temperatures,compression and combustion pressures,fuel consumption,power,and NOx-SOx-COx emissions.For instance,during the winter season,the cylinder compression pressure(pc)is recorded at 94 bar,while the maximum pressure(pz)reaches 110 bar.In the summer,pc experiences a decrease of 81 bar,while pz is measured at 101 bar.The emission of nitrogen oxides(NOx)exhibits a measurement of 784 parts per million(ppm)during winter and 744 in summer.The concentration of sulfur oxides(SOx)is recorded at 46 ppm in winter and 53 in summer.Given the current state of global warming and climate change,it is an undeniable fact that the impact of these phenomena will inevitably escalate.展开更多
为研究掺烧不同比例的乙醚对柴油机燃烧及排放特性的影响,以4190Z L C-2型船用中速机为研究对象,利用AVL_FIRE仿真软件构建燃烧室高压循环模型,在全负荷工况下对比实测与仿真缸压和放热率曲线,验证模型的准确性。在全负荷工况下,通过仿...为研究掺烧不同比例的乙醚对柴油机燃烧及排放特性的影响,以4190Z L C-2型船用中速机为研究对象,利用AVL_FIRE仿真软件构建燃烧室高压循环模型,在全负荷工况下对比实测与仿真缸压和放热率曲线,验证模型的准确性。在全负荷工况下,通过仿真模拟实验,在柴油中分别掺混体积分数为0%、5%、10%、15%的4种比例的乙醚,研究其对柴油机燃烧和排放特性的影响。结果表明:与燃烧纯柴油相比,使用柴油-乙醚混合燃料,缸内最大爆发压力和缸内最高温度均有所下降,对应的曲轴转角也稍有延后。增加乙醚的掺混比例,CO和NO的排放量均呈现降低趋势,碳烟排放略有增加。在反应过程中,乙醚加入延长了混合燃料的滞燃期,油气混合更加充分,放热过程稳定,提升柴油机的稳定性。当乙醚掺混体积分数为15%时,NO排放量较原机降低12.7%,CO排放量降低7.8%,碳烟排放量增大10.7%。展开更多
基金supported by the National Key Research and Development Program of China[Grant No.2017YFE0116100]the Postgraduate Research&Practice Innovation Program of Jiangsu Province,China[Grant No.KYCX20_2821].
文摘This paper aims to design a special exchanger to recover the exhaust gas heat of marine diesel engines used in small and medium-sized fishing vessels,which can then be used to heat water up to 55°C–85°C for membrane desalination devices to produce fresh water.A new exhaust-gas heat exchanger of fins and tube,with a reinforced heat transfer tube section,unequal spacing fins,a mixing zone between the fin groups and four routes tube bundle,was designed.Numerical simulations were also used to provide reference information for structural design.Experiments were carried out for exhaust gas waste heat recovery from a marine diesel engine in an engine test bench utilizing the heat exchanger.The experimental results show that the difference between heat absorption by water and heat reduction of exhaust gas is less than 6.5%.After the water flow rate was adjusted,the exhaust gas waste heat recovery efficiency was higher than 70%,and the exhaust-gas heat exchanger’s outlet water temperature was 55°C–85°C at different engine loads.This means that the heat recovery from the exhaust gas of a marine diesel engine meets the requirement to drive a membrane desalination device to produce fresh water for fishers working in small and medium-sized fishing vessels.
基金Sponsored by the Ministerial Level Advanced Research(10660060220)
文摘A hardware-in-the-loop simulating platform is developed to avoid designing defects caused by the complicated logical structure and multiple-functional buildup of the dectronic control unit（ECU）in modem diesel engines, and to diminish potential damages on components or human exposure to dangers in R＆D en- deavor. This plat-form consists of a computer installed with software Matlab/Simulink/RTW and dSPACE/ ControlDesk; a diesel engine ECU, and a dSPACE autobox which runs a real-time diesel engine model. A typical model of diesel engine with turbocharger and intercooler is presented. Based on this model our research is carried out with a real ECU to test its software control strategies. Results show that by using the diesel engine model downloaded inside, the hardware-in-the-loop platform can simulate diesel engine＇s working conditions and generate all kinds of sensor signals which ECU needs on a real-time basis. So the ECU control strategies can be validated and relevant parameters roughly calibrated.
文摘为了研究不同比例的异戊醇/柴油混合燃料在4190Z L C-2型船用中速柴油机中的燃烧和排放特性,运用AVL_FIRE仿真软件建立柴油机燃烧室模型,并通过台架实验验证其仿真模型的准确性。在仿真软件中通过调整异戊醇在柴油中的掺混比来研究混合燃料对柴油机燃烧和排放性能的影响。结果表明:掺混异戊醇有助于改变NO的生成规律,使NO在速燃期的生成量上升,在缓燃期与后燃期的生成量减少,并且总体生成的NO质量分数降低;随着异戊醇掺混比的上升,CO最终生成质量分数下降,Soot最终生成质量分数上升,同时生成的Soot质量分数峰值降低,在缓燃期的氧化速率增快,并因为较快的耗氧量使得最终生成的Soot质量分数比纯柴油的高。
文摘In comparison to onshore facilities,ships,and their machinery are subjected to challenging external influences such as rolling,vibration,and continually changing air&cooling water temperatures in the marine environment.However,these factors are typically neglected,or their consequences are deemed to have little effect on machinery,the environment,or human life.In this study,seasonal air&seawater temperature effects on marine diesel engine performance parameters and emissions are investigated by using a full-mission engine room simulator.A tanker ship two-stroke main engine MAN B&W 6S50 MC-C with a power output of 8600 kW is employed during the simulation process.Furthermore,due to its diverse risks,the Marmara Region is chosen as the application area for real-time average temperature data.Based on the research findings,even minor variations in seasonal temperatures have a significant influence on certain key parameters of a ship’s main engine including scavenge pressure,exhaust temperatures,compression and combustion pressures,fuel consumption,power,and NOx-SOx-COx emissions.For instance,during the winter season,the cylinder compression pressure(pc)is recorded at 94 bar,while the maximum pressure(pz)reaches 110 bar.In the summer,pc experiences a decrease of 81 bar,while pz is measured at 101 bar.The emission of nitrogen oxides(NOx)exhibits a measurement of 784 parts per million(ppm)during winter and 744 in summer.The concentration of sulfur oxides(SOx)is recorded at 46 ppm in winter and 53 in summer.Given the current state of global warming and climate change,it is an undeniable fact that the impact of these phenomena will inevitably escalate.
文摘为研究掺烧不同比例的乙醚对柴油机燃烧及排放特性的影响,以4190Z L C-2型船用中速机为研究对象,利用AVL_FIRE仿真软件构建燃烧室高压循环模型,在全负荷工况下对比实测与仿真缸压和放热率曲线,验证模型的准确性。在全负荷工况下,通过仿真模拟实验,在柴油中分别掺混体积分数为0%、5%、10%、15%的4种比例的乙醚,研究其对柴油机燃烧和排放特性的影响。结果表明:与燃烧纯柴油相比,使用柴油-乙醚混合燃料,缸内最大爆发压力和缸内最高温度均有所下降,对应的曲轴转角也稍有延后。增加乙醚的掺混比例,CO和NO的排放量均呈现降低趋势,碳烟排放略有增加。在反应过程中,乙醚加入延长了混合燃料的滞燃期,油气混合更加充分,放热过程稳定,提升柴油机的稳定性。当乙醚掺混体积分数为15%时,NO排放量较原机降低12.7%,CO排放量降低7.8%,碳烟排放量增大10.7%。
