Steel welded vertical large oil tank

Abstract

The invention provides a large steel welded vertical oil tank. The large steel welded vertical oil tank is provided with a tank bottom, a tank wall and a tank top. A transition connecting ring is arranged between the tank bottom and the tank wall and provided with an annular bottom section, an arc-shaped transition section and a vertical cylindrical section. The tank bottom is connected with the annular bottom section of the transition connecting ring in a welded mode. The tank wall is connected with the vertical cylindrical section of the transition connecting ring in a welded mode. The tank top can be a fixed top and can also be an outwards-floating top. The large steel welded vertical oil tank has the advantages that T-shaped joints of a tank wall and a tank bottom of an existing large oil tank and large fillet welds on the joints are omitted, main danger points of the whole oil tank are eliminated, and safe operation of the large oil tank is guaranteed, wherein the transition position between the tank wall and the tank bottom is not prone to low-cycle fatigue damage, an attachment weld of the transition portion between the tank wall and the tank bottom is not prone to tearing damage, the anti-seismic property of the large oil tank is greatly improved, and the anti-seismic property of the large oil tank is good.

Description

technical field [0001] The invention belongs to the field of chemical equipment, in particular to a steel welded vertical large oil tank. Background technique [0002] Oil tanks are the main equipment in the oil industry, used to store crude oil and refined oil. [0003] With the continuous increase of the national economy's demand for oil and the establishment of the national oil reserve system, the storage of crude oil continues to increase, and the capacity of the oil tanks built is also expanding. At present, the capacity of a single oil tank for crude oil reserves in my country has reached 15×10 4 m 3 , the capacity of the largest single unit abroad has reached 20×10 4 m 3 , therefore, the capacity of a single unit is 20×10 4 m 3 Large-scale oil tanks will become the focus of my country's future crude oil storage tank construction (see the paper "20 × 10 4 m 3 Stress Analysis and Safety Assessment of Extra Large Floating Roof Crude Oil Storage Tank" introduc...

AI Technical Summary

Problems solved by technology

[0016] Once a large oil tank full of oil is damaged, a large amount of oil will rush out of the tank in an instant, and the fire embankment may be washed away, and even cause a large-scale fire and explosion accident, and cause irreparable catastrophic environmental damage (see Introduction to the paper "Study on Leakage Characteristics of Large Oil Tank Rupture" written by Liu Qiang and others published in the third issue of "Contemporary Chemical Industry" in 2015)

[0017] It can be seen from the above that the existing vertical cylindrical steel welded large oil tank has the disadvantage that the edge of the large oil tank wall and the T-shaped joint at the bottom of the tank is caused by a large additional bending moment. Stress, and there is a large peak stress in the large fillet weld area, which makes the T-shaped joint a dangerous point of the entire oil tank, which brings great harm to the safe operation of large oil tanks: 1. Large oil tanks are entering and exiting During oil operation, as the liquid level in the oil tank changes, the stress at the T-shaped joint also changes, so this part is prone to low-cycle fatigue damage (see "Journal of Wuhan Engineering University" 2014 No. 2 The paper "Reliability Analysis of Large Fillet Weld Cracks of Large Storage Tanks" written by Wei Huazhong published in the journal, and the paper "Large Fillet Welds of Large Oil Tanks" written by Chen Zhiping published in the fifth issue of "Pressure Vessel" magazine in 2005 cited above Analysis of Peak Stress at Joints" and the paper "12.5×10 4 m 3 The main structure design of crude oil storage tank with external floating roof" introduction); 2. When uneven settlement of the foundation occurs, or when an earthquake causes the bottom of the oil tank to lift off (see "Sichuan Building Science Research" magazine, Issue 1, 2015 Published papers by Zhang Rulin et al., "Summary of the Current Situation and Development of Large-Scale Storage Tank Seismic Research", and the above-quoted paper by Wei Shulian, published in the third issue of "International Earthquake Dynamics" in 1995, "We Must Pay Attention to the Seismic Problems of Large Oil Storage Tanks" "Introduction, in GB50341-2003 "Code for Design of Vertical Cylindrical Steel Welded Oil Tanks" D.5 "Seismic Checking", the term "lifting off" is used instead of "lifting off"), the T-shaped joints of large oil tanks The large fillet welds in the large fillet welds are subjected to the tension in the vertical direction in a local area, and are prone to cracks and expansion to cause tear damage (see the paper written by Sun Jiangang et al. Research on Seismic Vulnerability of Vertical Storage Tanks Based on Probability Estimation Method", "Study on Leakage Characteristics of Large Oil Tank Rupture" written by Liu Qiang et al. published in the third issue of "Contemporary Chemical Industry" magazine in 2015, and "Petrochemical Equipment" magazine in 2003 The paper "12.5×10 4 m 3 The design of the main structure of crude oil storage tanks with external floating roofs”); 3. When a large oil tank encounters the dynamic load impact caused by an earthquake, the lower part of the tank wall will buckle like a foot (see “Oil and Gas Storage and Transportation” magazine, No. 12, 2008 The published paper "Stress Analysis and Buckling Stability of Large Oil Tanks" written by Chen Zhiping, and the paper "Seismic Research Status of Large Storage Tanks" written by Zhang Rulin et al. Introduced in "Summary of Development and Development", a large additional bending moment will be generated at the T-shaped joint of the large oil tank, and the edge stress caused by the additional bending moment will be superimposed on the original stress, which will greatly exceed the maximum stress that this part can bear. This part is prone to impact damage, so the seismic performance of large oil tanks is relatively poor (see the paper "We must pay attention to the seismic problems of large oil storage tanks" written by Wei Shulian published in the third issue of "International Earthquake Dynamics" magazine in 1995). "Introduction, and the introduction of the last part of the paper "China's Energy Issues and National Petroleum Reserves" written by Pan Jiahua published in the 12th issue of "Oil and Gas Storage and Transportation" in 2004, "The main types of oil tank accidents that occurred in history are as follows", " Introduction to the paper "Fault Tree Analysis Method for Assessing Earthquake Secondary Fires of Oil Storage Tanks" written by Zhong Jiangrong et al., published in the 6th issue of the Journal of Natural Disasters in 2013)

Images