【作者】 郑海啸；

【导师】 程乐鸣； 倪明江；

【作者基本信息】 浙江大学 ， 热能工程， 2006， 硕士

【摘要】 论文在试验验证自激式脉动流化床概念的基础上，对Rijke自激式脉动流化床的流化、脉动和传热特性进行了试验研究。论文工作主要分五部分： (1) 综述了国内外脉动燃烧技术的研究进展，讨论了流态化燃烧技术和脉动燃烧技术的特点，创新性地提出了将两者相结合的设想。 (2) 讨论了Rijke管脉动燃烧器的结构和脉动机理，实验研究了Rijke管脉动燃烧器的声学脉动特性和传热特性。分析了热释放强度和热源温度对激励Rijke管声脉动频率和强度的影响，得知热释放强度越大，脉动激励越容易，热源温度越高，脉动强度越高；以及脉动与否对换热系数的影响。 (3) 设计、搭建和运行了Rijke自激式脉动流化床，并通过可视化实验台观察到了燃烧温度650℃以上，静止床料高度≤30mm且空截面风速≤1.8m／s时，激励起声脉动的同时能够保持良好的流化状态，证明了自激式脉动流化床的可行性。 (4) 在该Rijke自激式脉动流化床实验台上进行了流化和脉动特性实验。获得了临界流化风速；时域和频域分析了床内各测点的压力信号，获得了脉动流化床的压力脉动特性，床内各点处压力为该点各次谐波压力分量和未建立脉动时原有的压力的叠加；分析了不同的流化风速和不同的静止床层高度对压力脉动的基波频率和振幅以及声脉动的基波频率和声压级的影响，确定了保证脉动流化的重要条件为：在使得充分流化的风速下，较高的燃烧温度，较低的流化风速和床层高度。 (5) 在该Rijke自激式脉动流化床实验台上进行了床内四种不同情况下的传热特性实验。研究了风速、脉动强度和静止床层高度对水冷夹套的换热系数的影响；表明脉动对传热有明显的促进作用，其中脉动流化床的换热系数最高，比Rijke管燃烧器和流化床高出约10％～20％，并确定了该Rijke管型脉动流化床最佳的运行工况。 在试验研究中脉动压力信号的测量较为困难，利用LabVIEW平台开发了高频脉动压力测量软件，并建立了高频压力信号测量系统，有效解决了床内高频脉动压力的测量问题。更多还原

【Abstract】 The thesis proved the concept of Self-pulsating Fluidized Bed and studied the fluidized, pulsating and heat transfer characteristic of a Rijke-type Self-pulsating Fluidized Bed experimentally. It mainly includes the five parts as following:(1) References on pulsating combustion technology were reviewed. Based on discussion of the characteristics of fluidized combustion technology and pulsating combustion technology, a novel concept Self-pulsating Fluidized Bed which combining both techniques’ advantages was brought forward.(2) As a research base, a Rijke tube pulsating combustor test rig was built. The pulsating and heat transfer characteristics of the Rijke tube were tested. The effects of heat release intensity and the heat source temperature on inspirng the pulsating frequency and intensity of Rijke tube were investigated. It was concluded that the pulsating would be stimulated more easily as the heat release intensity was higher, and the pulsating intensity was stronger as the heat source temperature was higher. The effect of pulsating on heat transfer was also measured.(3) A Rijke-type Self-pulsating Fluidized Bed test rig was designed and constructed. It was observed the bed material fluidized very well and the bed remained at a good fluidizing state with the inspired acoustic pulse when the bed operated at about 650℃ and the air velocity is below 1.8m/s. The concept of Self-pulsating Fluidized Bed was proved by a feasibale test.(4) The fluidizing and pulsating characteristics of the Rijke- type Self-pulsating Fluidized Bed was studied experimentally. The minumin iluidized velocity was obtained. With analyzing pressure signals along the tube by frequency time-domain and frequency-domain method, the pressure pulsating characteristics of the pulsating fluidized bed was obtained. The section also presented the effects of air velocity and static bed height on the fundamental wave frequency, amplitude of the pressure pulse, the fundamental wave acoustic frequency and the sound pressure level of the acoustic pulse. And it was confirmed that the main operation conditions of this Self-pulsating Fluidized Bed were higher combustion temperature, lower air velocity which insured fluidizing adequately and lower static bed height.(5) Heat transfer characteristics of the Rijke- type Self-pulsating Fluidized Bed at were researched by experiments at four different states. The influences of the air velocity, pulsating intensity and static bed height to the heat transfer coefficient were studied. The experiment results indicates that the heat transfer of the combustor was enhanced strongly when the pulse occurd. It was found the heat transfer coefficient of the Pulsating Fluidized Bed was the highest and its values were 10%~20% higher than a Rijke tube and a fluidized bed. The research gave the optimal operation state of the Rijke- type Self-pulsating Fluidized Bed.A special pressure measurement system and a related software based on Lab VIEW were developed to measure the high frequency pressure signals in the research. This work helps solving the measurement problem of high frequency pressure singals in the Rijke- type Self-pulsating Fluidized Bed successfully.更多还原