传热学研究中的某些前沿问题(some advances in heat transfer)-刘登瀛

Department of Thermal Power Engineering, North China Electric Power University (Beijing 102206)Research Group of Heat and Mass transfer, Room C125, Teaching Building III. Tel 86-10-80798627 NCEPUBJ传热学研究中的某些前沿问题Some Advances in Heat Transfer刘登瀛Liu Dengying热能动力工程前沿讲座 ：Department of Thermal Power Engineering, North China Electric Power University (Beijing 102206)Research Group of Heat and Mass transfer, Room C125, Teaching Building III. Tel 86-10-80798627 NCEPUBJ内容提纲内容提纲一一 当前当前 传热学发展的重要趋势二二 非平衡传递过程非平衡传递过程 传热学研究的新领域 传热学与其它学科的交叉与融合 先进能源系统中的传热新课题 结束语Department of Thermal Power Engineering, North China Electric Power University (Beijing 102206)Research Group of Heat and Mass transfer, Room C125, Teaching Building III. Tel 86-10-80798627 NCEPUBJ一 当前 传热学发展的重要趋势n 从 “经典 ”到 “超常 ”的转变大大拓宽了传热学的研究领域；极大地丰富和更新了传热学的研究成果n 与其它学科的 交叉 与 融合从根本上改变了传热学的研究目标与研究方法；有可能给传热学带来脱胎换骨的变化。Department of Thermal Power Engineering, North China Electric Power University (Beijing 102206)Research Group of Heat and Mass transfer, Room C125, Teaching Building III. Tel 86-10-80798627 NCEPUBJ内容提纲内容提纲一 当前传热学发展的重要趋势二二 非平衡传递过程非平衡传递过程 传热学研究的新领传热学研究的新领域域三 传热学与其它学科的交叉与融合四 先进能源系统中的传热新课题五 结束语Department of Thermal Power Engineering, North China Electric Power University (Beijing 102206)Research Group of Heat and Mass transfer, Room C125, Teaching Building III. Tel 86-10-80798627 NCEPUBJ二二 非平衡传递过程非平衡传递过程q “经典经典 ”传热理论的共同特征传热理论的共同特征q 热力学平衡状态与局域非平衡问题热力学平衡状态与局域非平衡问题q 热力学局域非平衡传热涉及的领域热力学局域非平衡传热涉及的领域Department of Thermal Power Engineering, North China Electric Power University (Beijing 102206)Research Group of Heat and Mass transfer, Room C125, Teaching Building III. Tel 86-10-80798627 NCEPUBJ宇宙飞船与航天飞机大规模集成电路与纳米计算机循环经济与节能新技术可再生能源与后续能源生命科学与克隆技术环境工程与人类健康Department of Thermal Power Engineering, North China Electric Power University (Beijing 102206)Research Group of Heat and Mass transfer, Room C125, Teaching Building III. Tel 86-10-80798627 NCEPUBJ微尺度传热 典型的超常传热1、超急速传热： 非傅立叶效应 非费克效应 爆发沸腾 温度测量的时空极限2、微纳米传热 : 微纳米传热的尺度效应 分子模拟3、微尺度热输运 : 自激振荡流热管 微型热驱动Department of Thermal Power Engineering, North China Electric Power University (Beijing 102206)Research Group of Heat and Mass transfer, Room C125, Teaching Building III. Tel 86-10-80798627 NCEPUBJ1 超急速传热超急速传热 (微时间与高热流微时间与高热流 )q 物体的温度变化率物体的温度变化率常规传热：常规传热： 10-3 1 K/s超急速传热：超急速传热： 103 107 K/s， 甚至更高甚至更高不是超高温传热，而是在微时间尺度和不是超高温传热，而是在微时间尺度和高热流作用下的高热流作用下的 热力学局域非平衡传热热力学局域非平衡传热Department of Thermal Power Engineering, North China Electric Power University (Beijing 102206)Research Group of Heat and Mass transfer, Room C125, Teaching Building III. Tel 86-10-80798627 NCEPUBJA. 非傅立叶导热效应非傅立叶导热效应q 傅立叶导热定律：傅立叶导热定律：隐含着热量传播速度为无穷大的隐含着热量传播速度为无穷大的假定，在超急速传热条件下，上述假定假定，在超急速传热条件下，上述假定不再成立。不再成立。 Department of Thermal Power Engineering, North China Electric Power University (Beijing 102206)Research Group of Heat and Mass transfer, Room C125, Teaching Building III. Tel 86-10-80798627 NCEPUBJCottano -Vemotte 非非 傅立叶模型（傅立叶模型（ C-V模型）模型）：展开得：展开得：q(r, t+)= -T(r, t) Department of Thermal Power Engineering, North China Electric Power University (Beijing 102206)Research Group of Heat and Mass transfer, Room C125, Teaching Building III. Tel 86-10-80798627 NCEPUBJ非傅立叶导热现象非傅立叶导热现象Department of Thermal Power Engineering, North China Electric Power University (Beijing 102206)Research Group of Heat and Mass transfer, Room C125, Teaching Building III. Tel 86-10-80798627 NCEPUBJ非傅立叶导热效应的实验验证非傅立叶导热效应的实验验证Department of Thermal Power Engineering, North China Electric Power University (Beijing 102206)Research Group of Heat and Mass transfer, Room C125, Teaching Building III. Tel 86-10-80798627 NCEPUBJ非傅立叶导热效应的实验验证非傅立叶导热效应的实验验证Department of Thermal Power Engineering, North China Electric Power University (Beijing 102206)Research Group of Heat and Mass transfer, Room C125, Teaching Building III. Tel 86-10-80798627 NCEPUBJ产生非傅立叶导热效应的条件产生非傅立叶导热效应的条件由 C-V模型可知，要修正项 大，必需：q 松弛时间 要大，在室温条件下：固体 =10-1410-10s； 气体 =10-1010-8s；多孔材料与生物质材料的 要长很多；在低温下， 将延长q 要高，即在微时间尺度和高热流作用下更容易产生非傅立叶效应Department of Thermal Power Engineering, North China Electric Power University (Beijing 102206)Research Group of Heat and Mass transfer, Room C125, Teaching Building III. Tel 86-10-80798627 NCEPUBJB. 非斐克扩散效应非斐克扩散效应Department of Thermal Power Engineering, North China Electric Power University (Beijing 102206)Research Group of Heat and Mass transfer, Room C125, Teaching Building III. Tel 86-10-80798627 NCEPUBJ传递机理与影响范围q 与导热不同的传递机理q 比非傅立叶效应更常见，影响范围更广Department of Thermal Power Engineering, North China Electric Power University (Beijing 102206)Research Group of Heat and Mass transfer, Room C125, Teaching Building III. Tel 86-10-80798627 NCEPUBJC. 爆发沸腾爆发沸腾q 沸腾机理：均质核沸腾过程控制因素不再是壁面状态，而是液体性质q 区别与常规沸腾的特征：气泡生长与上升速度快气泡数量大 4个数量级沸腾起始点和临界热负荷显著不同Department of Thermal Power Engineering, North China Electric Power University (Beijing 102206)Research Group of Heat and Mass transfer, Room C125, Teaching Building III. Tel 86-10-80798627 NCEPUBJ0 1s 2s 20s 40s 100s140s 200s 300s 450s 600s 900s典型的丙酮超急速爆发沸腾系列照片爆发沸腾时的气泡生长照片Department of Thermal Power Engineering, North China Electric Power University (Beijing 102206)Research Group of Heat and Mass transfer, Room C125, Teaching Building III. Tel 86-10-80798627 NCEPUBJD. 温度测量的时空极限温度测量的时空极限q 温度的微观表征在系统达到热平衡时，体系中个基本载热粒子的热运动速度应满足一定的统计分布规律q 微观载热粒子应满足的统计分布规律：分子系统： Maxwell-Boltzmann分布；电子系统： Fermi-Dirac分布；质子、声子系统： Bose-Einstein分布 .Department of Thermal Power Engineering, North China Electric Power University (Beijing 102206)Research Group of Heat and Mass transfer, Room C125, Teaching Building III. Tel 86-10-80798627 NCEPUBJ温度的微观极限温度的微观极限q 时间极限建立某种统计分布所需要的最小时间 热松弛时间；q 空间极限稳定满足该统计分布规律所需要的最小粒子数 平均自由程 .载热 粒子 气体分子 液体分子 金属 电 子 晶体声子平均自由程(nm)200 0.11 10 510热 松弛 时间 (s) (0.11)10-9 (0.11)10-12 (0.1100)10-15 (0.11)10-12Department of Thermal Power Engineering, North China Electric Power University (Beijing 102206)Research Group of Heat and Mass transfer, Room C125, Teaching Building III. Tel 86-10-80798627 NCEPUBJ微尺度温度测量方法微尺度温度测量方法q 光学方法q 扫描热量显微镜q 高频响应热敏电阻Department of Thermal Power Engineering, North China Electric Power University (Beijing 102206)Research Group of Heat and Mass transfer, Room C125, Teaching Building III. Tel 86-10-80798627 NCEPUBJ光学方法Department of Thermal Power Engineering, North China Electric Power University (Beijing 102206)Research Group of Heat and Mass transfer, Room C125, Teaching Building III. Tel 86-10-80798627 NCEPUBJ飞秒激光测量系统照片Department of Thermal Power Engineering, North China Electric Power University (Beijing 102206)Research Group of Heat and Mass transfer, Room C125, Teaching Building III. Tel 86-10-80798627 NCEPUBJ扫描热量显微镜Department of Thermal Power Engineering, North China Electric Power University (Beijing 102206)Research Group of Heat and Mass transfer, Room C125, Teaching Building III. Tel 86-10-80798627 NCEPUBJDepartment of Thermal Power Engineering, North China Electric Power University (Beijing 102206)Research Group of Heat and Mass transfer, Room C125, Teaching Building III. Tel 86-10-80798627 NCEPUBJDepartment of Thermal Power Engineering, North China Electric Power University (Beijing 102206)Research Group of Heat and Mass transfer, Room C125, Teaching Building III. Tel 86-10-80798627 NCEPUBJ2 微纳米传热q 微纳米传热与流动的尺度效应表现为：连续流动假定不再成立 , N-S方程和傅立叶定律被打破支配力变化，面体比非常大，表面影响变得非常重要Department of Thermal Power Engineering, North China Electric Power University (Beijing 102206)Research Group of Heat and Mass transfer, Room C125, Teaching Building III. Tel 86-10-80798627 NCEPUBJ尺度效应导致： Nu Gr 1/4