【摘要】：壓力容器是常見(jiàn)的過(guò)程裝備，由于工藝和結(jié)構(gòu)上的要求，經(jīng)常需要在壓力容器上安裝斜向或切向的非徑向接管，這種非徑向接管需要在容器上開(kāi)橢圓孔。開(kāi)孔的結(jié)果，，不僅削弱了壓力容器器壁的強(qiáng)度，而且在在開(kāi)孔附近產(chǎn)生嚴(yán)重的應(yīng)力集中，其峰值應(yīng)力往往高達(dá)容器薄膜應(yīng)力的數(shù)倍。因此，如何正確分析非徑向開(kāi)孔附近的應(yīng)力集中，采用合適的補(bǔ)強(qiáng)方法，是目前壓力容器設(shè)計(jì)中令人關(guān)注的課題。 本文以承受內(nèi)壓作用的壓力容器非徑向開(kāi)孔接管為研究對(duì)象，用有限元法分別模擬研究了非徑向接管的非徑向角度、接管厚度、接管內(nèi)伸長(zhǎng)度以及補(bǔ)強(qiáng)圈厚度等四個(gè)因素對(duì)非徑向接管開(kāi)孔區(qū)附近應(yīng)力分布的影響和應(yīng)力集中系數(shù)。 本文主要工作及所得結(jié)論如下： (1)非徑向接管的應(yīng)力集中系數(shù)隨著非徑向角度的增大而顯著增大，但并不是單調(diào)增大。容器的非徑向角度在25—45時(shí)，應(yīng)力集中系數(shù)較大。同時(shí)通過(guò)加圓倒角處理對(duì)比分析，發(fā)現(xiàn)打磨焊縫對(duì)于消除容器開(kāi)孔的殘余應(yīng)力具有積極的效果。 (2)接管補(bǔ)強(qiáng)的效果較好，但接管與筒體剛度差不應(yīng)過(guò)大，當(dāng)接管筒體厚度比達(dá)到1.2時(shí)，補(bǔ)強(qiáng)效果開(kāi)始降低。本文認(rèn)為，接管筒體厚度比t T一般取0.8—1.2之間較為合適。 (3)內(nèi)伸接管的補(bǔ)強(qiáng)效果有限，當(dāng)補(bǔ)強(qiáng)滿足要求時(shí)，不必再增加接管的內(nèi)伸長(zhǎng)度，否則會(huì)造成彎曲應(yīng)力的增加。如確需采用接管內(nèi)伸式補(bǔ)強(qiáng)，建議接管內(nèi)伸長(zhǎng)度控制在h2≤0.5T。 (4)補(bǔ)強(qiáng)圈補(bǔ)強(qiáng)效果僅次于接管補(bǔ)強(qiáng)。但是，由于補(bǔ)強(qiáng)圈使筒體局部壁厚加大，造成局部彎曲應(yīng)力增大，并且補(bǔ)強(qiáng)圈與筒體之間不能完全貼合，難以與筒體形成一個(gè)整體，所以抗疲勞性能差。通過(guò)有限元模擬結(jié)果可知，補(bǔ)強(qiáng)圈厚度在0.8T至1.2T之間較為合適。補(bǔ)強(qiáng)圈補(bǔ)強(qiáng)結(jié)構(gòu)不宜在高壓高溫容器上使用。 (5)本文借助空間解析幾何坐標(biāo)變換的理論以及回歸分析方法，推導(dǎo)出了半經(jīng)驗(yàn)半理論的非徑向接管應(yīng)力快速計(jì)算公式。通過(guò)這兩個(gè)形式簡(jiǎn)單的公式，可以比較容易地得到非徑向接管的應(yīng)力分布情況。
[Abstract]:Pressure vessel is a common process equipment. Due to the requirements of process and structure, it is often necessary to install oblique or tangential non-radial nozzle on the pressure vessel, which needs to open elliptical hole in the vessel. The results of opening not only weaken the strength of the wall of the pressure vessel, but also produce serious stress concentration near the hole. The peak stress is often several times higher than that of the membrane stress of the vessel. Therefore, how to correctly analyze the stress concentration near non-radial openings and adopt appropriate reinforcement methods is a subject of concern in the design of pressure vessels at present. In this paper, the non-radial nozzle of pressure vessel subjected to internal pressure is studied, and the non-radial angle and thickness of the non-radial nozzle are simulated by finite element method. The influence of four factors such as the elongation of the nozzle and the thickness of the reinforcing ring on the stress distribution and the stress concentration factor near the opening zone of the non-radial nozzle. The main work and conclusions are as follows: (1) the stress concentration factor of the non-radial nozzle increases significantly with the increase of the non-radial angle, but it is not monotonous. When the non-radial angle of vessel is 25-45, the stress concentration factor is larger. At the same time, it is found that grinding weld has a positive effect on eliminating the residual stress of the open hole of the vessel through the comparative analysis of adding circle chamfering. (2) the effect of nozzle reinforcement is better, but the stiffness difference between nozzle and cylinder should not be too big. When the thickness ratio of nozzle tube reaches 1.2, the reinforcement effect begins to decrease. In this paper, it is considered that the thickness ratio of the tubing tube to t T is generally between 0.8-1.2. (3) the reinforcement effect of the inner extension nozzle is limited. When the reinforcement meets the requirement, it is not necessary to increase the extension length of the nozzle, otherwise, the bending stress will be increased. If it is necessary to adopt the nozzle extension reinforcement, it is suggested that the extension of the pipe should be controlled at H2 鈮

本文編號(hào)：2374774