强化换热螺旋管成型工艺及其自动化设计

Design of Equipment for Manufacturing Helically-Coiled Tubes and Its Automatic Control System

螺旋管以其独特的构造在换热器设计中倍受青睐,其强化换热性能的研究必须以螺旋管的精确制作为前提.基于三点确定一个圆的原理以及螺旋升角计算方法,设计了以三个模具靠轮为支点,通过伺服电机并借助精密线性滑动电位器和PID闭环控制位置编码调整靠轮位置,达到准确确定螺旋管参数并自动化加工制作的目的.模具靠轮采用耐磨钢车制,设计适于弯制304不锈钢管外径6～50mm,螺旋径100～700mm,螺旋节距10～50mm,工作过程由软件控制,平均制作速度为0.6m/min,成品螺旋管螺旋径和螺旋节距最大误差分别为-3%和-4.3%,螺旋管管径截面最大圆度误差为0.09mm.

Helically-coiled tubes have been widely used for design of heat exchangers,and the manufacturing parameters are very important for heat transfer enhancement.All the important parameters could be designed more accurately based on the theorem＂three given points determine a circle＂and the calculation method of helix angle.Three die wheels made of wearable steel were used to determine the values of the diameter and pitch of coil by servo motors which worked with precision linear sliding rheostat and PID closed-loop control function.The design diameter range for 304steel was 6-50mm,coil diameter 100-700mm and pitch 10-50mm.A piece of software was developed to control the whole working process.The working velocity and the maximum manufacture error was about 0.6m/min and-4.3%,respectively,and the maximum roundness error of tubes was only 0.09mm.