發(fā)布時間：2018-06-30 02:23

  本文選題：高含硫天然氣 + 加熱爐盤管　； 參考：《中國石油大學(xué)(華東)》2015年碩士論文

【摘要】：在高含硫氣田濕氣輸送過程中,由于存在H_2S、CO_2和水,天然氣加熱爐盤管處于H_2S和CO_2共存的的酸性環(huán)境中,加熱爐盤管腐蝕比較嚴(yán)重,影響了加熱爐的正常運(yùn)行,降低了換熱效果。本文基于H_2S/CO_2共存體系中的反應(yīng)過程,對高硫酸性濕天然氣加熱爐盤管的腐蝕規(guī)律開展研究。通過對含硫氣田常用管材L360鋼進(jìn)行腐蝕實驗和數(shù)據(jù)分析,總結(jié)腐蝕速率的變化規(guī)律,并運(yùn)用SPSS軟件對腐蝕數(shù)據(jù)進(jìn)行回歸分析,建立了天然氣加熱爐盤管腐蝕預(yù)測模型。實驗結(jié)果表明,對腐蝕速率影響較大的因素是H_2S分壓、CO_2分壓、溫度和Cl-濃度。L360鋼中的合金元素Cr可增強(qiáng)鋼在酸性環(huán)境中的耐蝕性;均勻腐蝕速率隨H_2S分壓的升高逐漸升高;不同CO_2分壓下,L360鋼在H_2S/CO_2中腐蝕速率在CO_2分壓為2.5MPa時高達(dá)0.6297mm/a,且隨著CO_2分壓的升高,腐蝕速率呈現(xiàn)先下降后上升規(guī)律;腐蝕速率隨總壓的增大而增大,先緩慢升高后趨于平緩,但增幅不多,基本穩(wěn)定在同一水平;腐蝕速率隨溫度的變化呈現(xiàn)先升高后降低的趨勢,在70～90℃達(dá)到最大;隨著Cl-濃度的升高,L360鋼的腐蝕速率逐漸升高,當(dāng)Cl-濃度達(dá)到30mg/mL時,L360鋼的腐蝕速率達(dá)到最大,Cl-濃度大于30mg/mL后,L360鋼的腐蝕速率逐漸降低;pH4.76時,均勻腐蝕速率隨著腐蝕體系pH值的增大而逐漸降低,當(dāng)pH4.76時,腐蝕速率隨著腐蝕體系pH值的增大而逐漸增大。腐蝕速率與H_2S分壓、CO_2分壓、溫度和Cl-濃度間呈非線性關(guān)系,擬合了腐蝕預(yù)測模型為:V =-21.553P_(H_2S)~2 +5.875P_(H_2S) +0.065P_(CO_2)~2-0.138P_(CO_2)-0.00005561T~2 +0.009T-0.00002132 C_(Cl~-)~3 +0.001C_(Cl~-)~2-0.016C_(Cl~-)+0.116自變量P_(H_2S)~2,P_(H_2S),P_(CO_2)~2,P_(CO_2),T~2,T,C_(Cl~-)~3,C_(Cl~-)~2,C_(Cl~-)的回歸系數(shù)的顯著性水平在數(shù)值上均遠(yuǎn)遠(yuǎn)小于0.05,可以判定,所有的回歸模型的回歸系數(shù)都是顯著的。擬合的腐蝕預(yù)測模型驗證表明,最大誤差為9.87%,平均誤差為8.07%,腐蝕預(yù)測模型精度滿足現(xiàn)場要求。研究結(jié)果對于高含硫氣田天然氣加熱爐盤管的腐蝕預(yù)測提供實驗數(shù)據(jù)及借鑒意義。
[Abstract]:In the process of wet gas transportation in high sulfur gas field, due to the existence of H2SCO2 and water, the coils of natural gas reheating furnace are in the acidic environment where H _ 2S and CO _ 2 coexist. The corrosion of reheating furnace coil is serious, which affects the normal operation of heating furnace and reduces the heat transfer effect. Based on the reaction process of H _ 2s / CO _ 2 co-existing system, the corrosion law of high sulfur acid wet natural gas heating furnace coils is studied in this paper. Through the corrosion experiment and data analysis of L360 steel, a common pipe material in sulfur-bearing gas field, the variation law of corrosion rate is summarized, and the corrosion prediction model of natural gas heating furnace coils is established by using SPSS software to carry out regression analysis of corrosion data. The experimental results show that the major factors affecting the corrosion rate are the partial pressure of H _ 2S and CO _ 2, the alloy element Cr in Cl-concentration. L360 steel can enhance the corrosion resistance of steel in acid environment, and the uniform corrosion rate increases with the increase of partial pressure of H _ 2S. Under different CO2 partial pressures, the corrosion rate of L360 steel in H2s / COS-2 is as high as 0.6297mm / a when the partial pressure is 2.5MPa, and with the increase of CO _ 2 partial pressure, the corrosion rate decreases first and then rises; the corrosion rate increases with the increase of total pressure, and then increases slowly. The corrosion rate of L360 steel increased gradually with the increase of Cl-concentration, and the corrosion rate of L360 steel increased gradually with the increase of Cl-concentration, and then decreased with the change of temperature, and the corrosion rate of L360 steel increased gradually with the increase of Cl-concentration, and the corrosion rate of L360 steel increased gradually with the increase of Cl-concentration. When the concentration of Cl- is 30 mg / mL, the corrosion rate of L360 steel reaches the maximum when the concentration of Cl- is more than 30 mg / mL, and the corrosion rate of L360 steel decreases gradually with the increase of pH value of corrosion system, and when pH value is 4.76, the corrosion rate of L360 steel decreases gradually with the increase of pH value of corrosion system, and the corrosion rate of L360 steel decreases gradually with the increase of pH value of corrosion system. The corrosion rate increases with the increase of pH value. There is a nonlinear relationship between corrosion rate and H _ 2S partial pressure, CO _ 2 partial pressure, temperature and Cl-concentration. 鎷熷悎浜嗚厫铓，

本文編號：2084434