摘要脉动传热作为非稳态流动换热技术工程应用的一类典型代表,具有重要的研究价 值。本文设计了往复泵脉动发生器为实验提供脉动源,提出了合理的脉动流流量测量 方案和温度测量方法,搭建起包括水循环系统、脉动源系统、板式换热器以及数据采 集系统在内的实验台。在冷水入口压力值分别为 0。03MPa、0。07MPa 的两种压力情况 下,雷诺数 Re 范围为 3774-7313,脉动频率ƒ范围为 0。55-1。06Hz,通过实验方法对 板式换热器换热特性进行了研究。研究发现:脉动的存在能够显著的提高换热器的对 流换热系数,脉动强化换热效果主要与雷诺数、压力等因素有关。稳态时,对流换热 系数随着雷诺数的增大而增大。脉动条件下,压力相同,雷诺数越大,脉动流对强化 换热的提高就越显著;雷诺数相同,压力越高,脉动流产生的换热性能就越好。 81368
毕业论文关键词:脉动流;板式换热器;往复泵
Abstract Pulsating heat transfer as a typical representative of non-steady flow for thermal engineering application, has its important research value。 This paper designed a reciprocating pump pulse generator to provide pulsation source for experiment, put forward the reasonable pulsating flow measurement scheme and temperature measuring method, set up a test bench, including water circulation system, pulsation source system, plate heat exchanger and data acquisition system。 When the cold water inlet pressure values were 0。03 MPa, 0。07 MPa, the experiments were performed over a range of 3174≤Re≤7313 and 0。55Hz≤ƒ≤1。06Hz。 Also, the thesis made a research on the heat transfer characteristics of the plate heat exchanger by using controlling variable method, and the study found that the existence of the pulsation can significantly improve the convective heat transfer coefficient of heat exchanger and that the effect of pulsating strengthening heat transfer is mainly related to factors like the Reynolds number and pressure。 At steady state, the convective heat transfer coefficient increases as the Reynolds number increases。 However, under the condition of pulsating, with the same pressure, the greater the Re, the more significant the enhancement of the pulsating strengthening heat transfer ; but, with the same Re, the higher the pressure, the better performance of the pulsating flow the heat transfer。
Keywords: Pulsating flow; Plate heat exchanger; Reciprocating pump
目 录
第一章 绪论 1
1。1 课题选题背景及意义 1
1。2 脉动流换热研究文献综述 1
1。2。1 国内研究现状 2
1。2。2 国外研究现状 3
1。3 脉动流换热机理认识 4
第二章 脉动流换热实验系统及装置 8
2。1 实验系统和实验方法 8
2。1。2 换热实验台的搭建 8
2。1。2 实验测试方法 9
2。2 脉动源描述 10
2。2。1 脉动发生器 10
2。2。2 脉动特性 10
2。3 压力与流量的测量 11
2。3。1 进出口压力的测量 11
2。3。2 脉动流量的测量 11
2。4 板式换热器与温度测量 12
2。4。1 板式换热器