摘要: 这次课题的是根据给定的不同制热量,给定进水温度,出口水温。运用VB设计出以焊接钛螺纹管换热器。通过计算综合传热系数K和钛光管的换热面积A,根据螺纹管换热器外形尺寸,使螺纹管的换热量等于光管的换热量,分析计算在不同螺纹的节距、螺旋角度、螺纹深度、肋片厚度所需螺纹管长度,通过对长度的对比,设计最佳螺纹管换热器。在设计过程中,螺纹管的阻力计算是主要的难题,由于没有可参考的资料,我选择了微翅片式的方式来计算各项阻力。最后通过课题研究发现,无论是管内热媒还是管外冷媒的阻力都大了很多,同时相同长度的螺纹管的换热效果是光管的1-2倍,不仅仅面积增大了,也因为管内液膜厚度的减小,降低液阻,大大提高了换热器的效果,减小了换热器的体积。35845
毕业论文关键词: 螺纹管;换热量;微翅片;换热效果增强;阻力增大
The Program Design of Heat Exchanger Hot Water Pipe Thread
Abstract: This subject is using VB to design the welding of titanium threaded pipe heat exchanger according to different given heat capacity, given inlet temperature, given outlet temperature. By calculating the area of titanium tube heat exchange A and integrated heat transfer coefficient K , according to the spiral tube heat exchanger dimensions, make tube heat exchange equal to thread tube the heat exchange , analysis and calculation in different thread pitch, helix angle, thread depth, fin thickness required for threaded pipe length, by comparison the length, the optimal design of spiral tube heat exchanger. In the design process, the threaded pipe resistance calculation is the main problem, because there is no reference information, I chose the way to calculate the resistance in micro fin type. The research found that, both heat medium into tube or refrigerant resistance out tube is much larger, at the same time the same the length of the threaded tube heat transfer effect is 1-2 times of light pipe, not only the area increased, but also because of tube film thickness reduced, reduce fluid resistance, greatly improves the heat transfer the effect, reduce the volume of the heat exchanger.
Keywords: Threaded pipe; Heat transfer; Micro-finned; The effect of heat transfer enhancement; The resistance increases;
目录
摘要 i
Abstract i
目录 iii
1 绪论 1
1.1 钛炮介绍 1
1.2 轧制成螺纹的原因及优势 2
2 分析 3
2.1 螺纹管的加工方法与传热特性 3
2.2 螺纹盘管的使用寿命分析 3
3 设计 4
3.1 光管的传热计算 4
3.1.1 计算钛光管热媒换热流速 4
3.1.2 计算钛光管热媒换热系数 10
3.1.3 光管冷媒换热系数计算: 18
3.1.4 综合换热系数计算 26
3.1.5 光管阻力计算 30
3.2 螺纹管的传热及阻力计算 40
3.2.1 螺纹管管外热媒流速计算 40
3.2.2 计算钛螺纹管热媒换热系数 43
3.2.3 螺纹管管内换热系数计算 46
3.2.4 螺纹管长度计算 51
3.2.5 螺纹管阻力计算 75
4 结论 81
致谢 83
参考文献 84
1 绪论
换热器是化工、石油、制药及能源等行业中应用相当广泛的单元设备之一。据统计,在现代化学工业中所用换热器的投资大约占设备总投资的30%,在炼油厂中换热器的占全部工艺设备的比重要更大,而海水淡化工艺装置则几乎全部是由换热器组成的。上世纪发生的能源危机,有利的促进了传热强化技术的发展。为了节能减低能耗,提高工业生产的经济效益,要求开发适用不同工业过程的高效能换热设备。因此,高效换热器的开发与研究始终是人们关注的课题,国内外也先后推出一系列的新型高效换热器[ ]。 VB螺纹管热水换热器的程序设计+源程序:http://www.youerw.com/zidonghua/lunwen_33998.html