焦炭塔熱應力分析計算

趙志陽，欒江峰，謝騰騰, 崔明吉

（1. 遼寧石油化工大學 機械工程學院，遼寧 撫順 113001; 2. 撫順遠宏石化設備科技開發制造有限公司，遼寧 撫順 113008）

焦炭塔熱應力分析計算

趙志陽1，欒江峰1，謝騰騰1, 崔明吉2

（1. 遼寧石油化工大學 機械工程學院，遼寧 撫順 113001; 2. 撫順遠宏石化設備科技開發制造有限公司，遼寧 撫順 113008）

利用ABAQUS軟件模擬出了焦炭塔工作周期內的溫度變化、應力變化。采用順序耦合的方法分析焦炭塔所受的熱應力。分析從新塔準備直至老塔處理，其中共包括５個工作階段。結果顯示，幾個階段的溫度場分布對應力結果有顯著影響。試壓、油氣預熱、生焦的初始階段比較類似，都處于溫度上升階段，最大應力出現在裙座部位，分別為183.6、242.7、250.4 MPa，且焊縫處應力大于筒體。吹汽階段塔體溫度下降，焊縫處應力小于筒體應力。水冷階段的應力分布類似于溫度分布，存在一個隨冷焦水不斷移動的高應力截面，其中最大應力可達400.4 MPa，已超過了材料的屈服極限，導致筒體出現了局部塑性變形。經反復循環，會引發“熱應力棘輪”現象，由于塑性變形的不斷積累，故造成焦炭塔的鼓脹現象。

焦炭塔；溫度；熱應力；耦合分析

Abstract:Software ABAQUS was used to simulate the changes of temperature and stress of coke tower in the working period. The sequential coupling method was used to analyze the thermal stress of coke tower. Thermal stress analysis of the five periods was conducted firstly. The results showed that, the temperature field distribution obviously affected the thermal stress results. There was a temperature rising during the period of pressure test, oil preheating and coking,the thermal stress of these three periods was similar, the max stress located in the skirt and the maximum values were 183.6, 242.7 and 250.4 MPa, respectively. The stress of the weld was greater than that of the cylinder. The temperature reduced at the stage of steam blowing, and the stress of the weld was less than that of the cylinder. The stress distribution was similar to the temperature distribution during water cooling. There was a high stress gradient section which was moving with the water. The max stress was 400.4 MPa, which exceeded the yield limit of the material to cause the local plastic deformation. Thermal stress ratchet will occur after lots of process cycles. The plastic deformation will accumulate constantly, which can eventually lead to the distortion of the tower.

Key words:Coke tower; Temperature;Thermal stress;Coupling analysis

延遲焦化屬于煉廠二次加工方式，其工藝簡單，成本低，被廣泛應用在重質油的加工中，同時也是提高煉油廠輕質油收率的重要手段。作為延遲焦化裝置中核心設備的焦炭塔，向大型化發展是其必然趨勢。焦炭塔是典型的高應力低周循環的壓力容器，操作工藝嚴格，具有很長的循環周期，并且循環過程中不斷承受著熱載荷與機械載荷的反復作用。……