本文選題：含蠟原油 + 管道和泵站　； 參考：《西南石油大學(xué)》2015年碩士論文

【摘要】：我國生產(chǎn)的大部分原油為含蠟原油,且管輸含蠟原油的工藝多采用加熱輸送。在含蠟原油加熱輸送的過程中,管壁結(jié)蠟會給管道輸送帶來很大的安全隱患,同時(shí)也會造成很大的能量(熱能和壓能)損耗。因此,研究站間結(jié)蠟規(guī)律,弄清蠟沉積對于管道和泵站系統(tǒng)工作特性的影響,建立模型預(yù)測管道中蠟沉積分布情況,對于提高管道系統(tǒng)的輸送效率,確保原油的安全輸送和制定合理的清管方案有著重要的實(shí)際意義。為此,本文以含蠟熱油管道系統(tǒng)為研究對象,展開了以下主要研究內(nèi)容。 在站間含蠟熱油管道實(shí)際運(yùn)行過程中,原油物性及摩阻特性會隨沿線油溫的降低而不斷變化,結(jié)蠟段管道的有效流通面積和傳熱系數(shù)將隨著蠟層厚度的增加而不斷減小,綜合以上因素,同時(shí)計(jì)入沿程摩擦熱的影響,對壓降反算蠟層厚度的水力學(xué)平均蠟層厚度算法進(jìn)行了改進(jìn),并利用MATLAB7.0編制了相應(yīng)的計(jì)算程序。 通過OLGA建立了站間等距的水平輸油管道系統(tǒng)模型,各站間在相同的外界條件和輸送同樣油品的情況下,依次對不同的泵站升壓方式：定速單泵、定速雙泵串聯(lián)和變速單泵進(jìn)行了站間管道蠟沉積過程的模擬。根據(jù)模擬結(jié)果,分析了站間管道蠟沉積對不同型號離心泵的工作特性影響,研究了站間管道蠟沉積的分布規(guī)律和泵型選擇對站間蠟沉積分布的影響。 根據(jù)大慶原油隨溫度變化的物性數(shù)據(jù),采用最小二乘法回歸求得物性公式中的常數(shù)項(xiàng)。根據(jù)鐵嶺至鞍山沿線在四季輸油中的運(yùn)行參數(shù),應(yīng)用本文結(jié)蠟段平均蠟層厚度模型計(jì)算了不同季節(jié)、不同運(yùn)行時(shí)間段下的蠟層厚度,并結(jié)合OLGA模擬結(jié)果與大慶原油蠟沉積速率預(yù)測模型,對鐵嶺站與沈陽站站間管線的蠟沉積規(guī)律及其蠟沉積對管道系統(tǒng)工作特性的影響作了分析。 通過以上的分析與研究,得出以下結(jié)論：析蠟高峰點(diǎn)以后的管壁處剪切應(yīng)力、原油黏度以及徑向溫度梯度是影響蠟沉積速率的主要因素,其中徑向溫度梯度是首要影響因素,而當(dāng)?shù)販厣邥r(shí),徑向溫度梯度對于蠟沉積速率的影響有所減弱,且地溫升高越多,減弱幅度越大；站間沿線結(jié)蠟分布情況與泵站所選泵型直接相關(guān),對于含蠟熱油長輸管道,泵站在選擇用泵時(shí),更應(yīng)選擇揚(yáng)程與流量特性曲線較陡降的泵；大慶原油站間析蠟高峰區(qū)的溫度區(qū)間為40℃左右,此溫度區(qū)間正好處于站間II區(qū)(析蠟點(diǎn)與反常點(diǎn)之間)內(nèi),一年四季中,若1I區(qū)長度越長,則站間管道結(jié)蠟情況越嚴(yán)重。另外,結(jié)蠟高峰區(qū)內(nèi)的蠟沉積速率相差不大,因此,站間高峰區(qū)越長,蠟沉積分布將越近視為“階梯型”。
[Abstract]:Most of the crude oil produced in China is waxy crude oil, and the process of pipe transportation of waxy crude oil is mostly heated. In the process of heating and transporting waxy crude oil, wax deposit on pipe wall will bring great hidden trouble to pipeline transportation, and also cause great loss of energy (heat energy and pressure energy) at the same time. Therefore, the law of wax deposition between stations, the influence of wax deposition on the working characteristics of pipeline and pumping station system, and the establishment of model to predict the distribution of wax deposition in pipeline system can improve the transportation efficiency of pipeline system. It is of great practical significance to ensure the safe transportation of crude oil and to formulate a reasonable pipe-clearing scheme. Therefore, this paper takes the waxy hot oil pipeline system as the research object, and carries out the following main research contents. During the actual operation of the waxy hot oil pipeline between stations, the physical properties and friction characteristics of crude oil will change with the decrease of oil temperature along the line, and the effective circulation area and heat transfer coefficient of the pipeline will decrease with the increase of wax thickness. Based on the above factors and taking into account the influence of the heat of friction along the path, the average thickness of wax layer in hydraulics with pressure drop is improved, and the corresponding calculation program is compiled by MATLAB7.0. The model of horizontal oil pipeline system with equal distance between stations is established by OLGA. Under the same external conditions and the same oil products, the pressure of different pumping stations is increased in turn: constant speed single pump, The process of wax deposition in pipeline between stations was simulated by two constant speed pumps in series and one pump with variable speed. Based on the simulation results, the effects of pipeline wax deposition on the working characteristics of different types of centrifugal pumps are analyzed, and the distribution law of wax deposition between stations and the influence of pump type selection on the distribution of wax deposition between stations are studied. According to the physical property data of Daqing crude oil varying with temperature, the constant term in the physical property formula is obtained by least square regression. According to the operating parameters of Tieling to Anshan in the four seasons oil transportation, the wax layer thickness of different seasons and different operating periods is calculated by using the average wax layer thickness model of the wax deposit section in this paper. Combined with OLGA simulation results and Daqing crude oil wax deposition rate prediction model, the wax deposition law of pipeline between Tieling station and Shenyang station and the influence of wax deposition on the working characteristics of pipeline system are analyzed. Through the above analysis and research, the following conclusions are drawn: the shear stress at the pipe wall after the peak point of wax evolution, the viscosity of crude oil and the radial temperature gradient are the main factors affecting the wax deposition rate, among which the radial temperature gradient is the primary factor. When the ground temperature rises, the influence of radial temperature gradient on wax deposition rate is weakened, and the more the ground temperature rises, the greater the weakening amplitude is, and the distribution of wax deposition along the interstation is directly related to the pump type selected by the pump station, and for the waxy hot oil long distance transportation pipeline, the distribution of wax deposition along the interstation is directly related to the pump type selected by the pump station. When the pump is selected for pump use, the pump with steep drop of lift and flow characteristic curve should be selected, and the temperature range of wax precipitation peak area between Daqing crude oil stations is about 40 鈩，

本文編號：1932513