胀接压力与初始间隙对换热器胀接质量的影响

Effect of Expansion Pressure and Initial Clearance on Expansion Joint Quality of Heat Exchanger

为研究换热管-管板胀接压力与初始间隙对换热器胀接质量的影响,采用胀接参数化模拟研究方法对液压胀接进行可靠性研究,建立换热管-管板胀接的弹塑性参数化几何模型,对不同的换热管-管板胀接压力和初始间隙进行研究,得到换热管残余等效应力、残余接触应力大小及分布规律。研究表明:胀接压力相同、间隙不同时,卸载后残余等效应力和残余接触应力值差别较小;初始间隙相同,胀接压力不同时,卸载后残余应力和残余接触应力值差别较大;换热管的残余等效应力和残余接触应力随着胀接压力的增大而增大,其变化趋势一致;当材料为Ti31钛合金、胀接压力为183 MPa时换热管与管板的初始间隙消除。研究结果为换热器最佳胀接性能优化及胀接质量的提高提供了依据。

In order to study the effects of heat transfer tube-tube plate expansion pressure and initial gap on heat exchanger expansion quality, the reliability of the hydraulic expansion joint was studied by the method of expansion parameterized simulation, and the elasto-plastic parameterized geometric model of heat exchange tube-tube plate expansion joint was established, and different expansion joint pressure and initial clearance of heat exchange tube-tube plate were performed. The residual equivalent stress, residual contact stress and distribution law of heat transfer tubes were obtained. The results show that when the expansion joint pressure is the same and the gap is different, the different of residual equivalent stress and residual contact stress value after unloading are smaller;When the initial gap is the same and the expansion pressure is different, residual stress and residual contact stress after unloading are quite different. The residual contact stress on the outer surface of the heat exchange tube increases with the increase of expansion joint pressure, and the residual equivalent stress also increases with the increase of the expansion joint force, and the change trend is consistent. When the material is Ti31 titanium alloy and the expansion pressure is 183 MPa, the initial clearance between heat exchanger tube and tube sheet is eliminated. The results provide the basis for optimizing the optimal expansion joint performance of heat exchangers and improving the quality of expansion joints.