矩形通道内沸腾换热特性及可视化研究
|
摘要
考虑到内燃机缸盖结构的复杂性,其内部冷却通道的换热特性及沸腾状态难以用试验手段进行准确的分析与监测。以简化的矩形流道作为有效的研究对象,针对于流速、压力、温度等流动参数对沸腾换热的影响展开试验研究,并利用高速相机监测不同过热度下的沸腾现象。研究表明:适当的降低流速可以在不影响换热的情况下优化冷却系统的结构尺寸,而提高冷却介质的温度和压力反而会降低沸腾换热效率。气泡的数量、尺寸均可反应出不同的沸腾换热状态,同时气泡的演化行为(生成、滑移、聚合、脱离、消失)可以在冷却介质中造成扰动,从而促进换热的发生。为内燃机缸盖沸腾换热方式的设计提供一定的理论参考。
Considering the complex structure of the cylinder head of internal combustion engine, The heat transfer characteristics of internal cooling passages and boiling state are difficult for analysis and monitoring accurately by means of tests. Simplified rectangular channel as a valid object of study,Analyzes the impact of flow rate,pressure,temperature and other parameters on the boiling heat transfer,And using high-speed cameras to detect the phenomenon of boiling under different agree of super heat.Studies have shown that:Appropriate reducing the flow rate of the cooling system can optimize the structure size without affecting the heat transfer,but increasing the cooling medium temperature and pressure will reduce the boiling heat transfer efficiency. Number of the bubbles,the size of the reaction may be a different state of boiling heat,at the same time,evolutionary behavior of bubbles(growth,slip,aggregation,detachment,disappearance)can cause disturbance in the cooling medium,thus contributing to the occurrence of heat transfer. Providing a theoretical reference for boiling transfer design manner of the internal combustion engine cylinder head.
Considering the complex structure of the cylinder head of internal combustion engine, The heat transfer characteristics of internal cooling passages and boiling state are difficult for analysis and monitoring accurately by means of tests. Simplified rectangular channel as a valid object of study,Analyzes the impact of flow rate,pressure,temperature and other parameters on the boiling heat transfer,And using high-speed cameras to detect the phenomenon of boiling under different agree of super heat.Studies have shown that:Appropriate reducing the flow rate of the cooling system can optimize the structure size without affecting the heat transfer,but increasing the cooling medium temperature and pressure will reduce the boiling heat transfer efficiency. Number of the bubbles,the size of the reaction may be a different state of boiling heat,at the same time,evolutionary behavior of bubbles(growth,slip,aggregation,detachment,disappearance)can cause disturbance in the cooling medium,thus contributing to the occurrence of heat transfer. Providing a theoretical reference for boiling transfer design manner of the internal combustion engine cylinder head.
引文
[1]易刚,林剑峰,侯延星.发动机缸盖加工关键工艺研究[J].机械设计与制造,2011(6):84-85.(Yi Gang,Lin Jian-feng.Research on key technics for machining cylind-er Head[J].Machinery Design&Manufacture,2011(6):84-85.)
[2]傅松.缸盖冷却水套内沸腾换热特性的研究[D].济南:山东大学,2010.(Fu Song.Research on boiling heat transter characteristics of coolingwater-jacket in cylinder head[D].Ji’nan:Shandong University,2010.)
[3]李智,黄荣华,程晓军.内燃机缸盖水腔内过冷沸腾数值模型研究[J].内燃机学报,2010,28(3):247-252.(Li Zhi,Huang Rong-hua.Research of subcooled boiling numerical mod-els in cylinder-head water-jacket of internal combustion engines[J].Transactions of CSICE,2010,28(3):247-252.)
[4]何联格,左正兴,向建华.气缸盖冷却水腔内两相流动沸腾传热仿真研究[J].西安交通大学学报,2013,47(1):21-26.(He Lian-luo,Zuo zheng-xing,Xiang Jian-hua.Simulation of two-phaseflow boiling heat transfer in cylinder head cooling water jacket[J].Jour-nal of Xi’an Jiaotong University,2013,47(1):21-26.)
[5]Klimenko,V. V.Heat transfer intensity at forced flow boiling of cryogenicLiquids in Tubes[J].Cryogenics,1982,22(11):569-576.
[6]张萍,童亚拉,欧阳光耀.基于红外成像技术的缸盖热裂纹探测方法[J].激光与光电子学进展,2010(11):49-53.(Zhang Ping,Tong Ya-la,Ouyang Guang-yao.Detecting thermal flaw in-ner cylinder herd based on infrared thermograph technology[J].Laser&Optoelectronics Progress,2010(11):49-53.)
[7]李智,黄荣华.内燃机缸盖水腔内过冷沸腾现象的数值模拟方法综述[J].湖北省内燃机学会2009年学术年会论文集,2009.(Li Zhi,Huang Rong-hua.Methods of numerical simulation engine headcooling water cavity boiling phenomenon[J].Hubei Internal CombustionEngine Society 2009 Annual Conference Proceedings,2009.)
[8]Ajotikar N,Eggart B J,Miers S A.Nucleate boiling identification and ut-ilization for improved internal combustion engine efficiency[C]//ASME2010 Internal Combustion Engine Division Fall Technical Conference.American Society of Mechanical Engineers,2010:949-958.
[9]董非,郭晨海,范秦寅.发动机冷却水腔内沸腾传热的模拟研究[J].内燃机工程,2011,32(4):76-82.(Dong Fei,Guo Chen-hai,Fan Qin-yan.Simulation boiling heat transferin cooling water jacked of engine[J].Chinese Internal Combustion Eng-ine Engineering,2011,32(4):76-82.)
[10]Lee H S.Heat transfer predictions using the chen correlation on subco-oled flow boiling in a standard IC engine[R].SAE Technical Paper,2009,2009-01-1530.
[2]傅松.缸盖冷却水套内沸腾换热特性的研究[D].济南:山东大学,2010.(Fu Song.Research on boiling heat transter characteristics of coolingwater-jacket in cylinder head[D].Ji’nan:Shandong University,2010.)
[3]李智,黄荣华,程晓军.内燃机缸盖水腔内过冷沸腾数值模型研究[J].内燃机学报,2010,28(3):247-252.(Li Zhi,Huang Rong-hua.Research of subcooled boiling numerical mod-els in cylinder-head water-jacket of internal combustion engines[J].Transactions of CSICE,2010,28(3):247-252.)
[4]何联格,左正兴,向建华.气缸盖冷却水腔内两相流动沸腾传热仿真研究[J].西安交通大学学报,2013,47(1):21-26.(He Lian-luo,Zuo zheng-xing,Xiang Jian-hua.Simulation of two-phaseflow boiling heat transfer in cylinder head cooling water jacket[J].Jour-nal of Xi’an Jiaotong University,2013,47(1):21-26.)
[5]Klimenko,V. V.Heat transfer intensity at forced flow boiling of cryogenicLiquids in Tubes[J].Cryogenics,1982,22(11):569-576.
[6]张萍,童亚拉,欧阳光耀.基于红外成像技术的缸盖热裂纹探测方法[J].激光与光电子学进展,2010(11):49-53.(Zhang Ping,Tong Ya-la,Ouyang Guang-yao.Detecting thermal flaw in-ner cylinder herd based on infrared thermograph technology[J].Laser&Optoelectronics Progress,2010(11):49-53.)
[7]李智,黄荣华.内燃机缸盖水腔内过冷沸腾现象的数值模拟方法综述[J].湖北省内燃机学会2009年学术年会论文集,2009.(Li Zhi,Huang Rong-hua.Methods of numerical simulation engine headcooling water cavity boiling phenomenon[J].Hubei Internal CombustionEngine Society 2009 Annual Conference Proceedings,2009.)
[8]Ajotikar N,Eggart B J,Miers S A.Nucleate boiling identification and ut-ilization for improved internal combustion engine efficiency[C]//ASME2010 Internal Combustion Engine Division Fall Technical Conference.American Society of Mechanical Engineers,2010:949-958.
[9]董非,郭晨海,范秦寅.发动机冷却水腔内沸腾传热的模拟研究[J].内燃机工程,2011,32(4):76-82.(Dong Fei,Guo Chen-hai,Fan Qin-yan.Simulation boiling heat transferin cooling water jacked of engine[J].Chinese Internal Combustion Eng-ine Engineering,2011,32(4):76-82.)
[10]Lee H S.Heat transfer predictions using the chen correlation on subco-oled flow boiling in a standard IC engine[R].SAE Technical Paper,2009,2009-01-1530.