發(fā)布時間：2018-03-01 09:26

  本文關(guān)鍵詞： 磁共振成像 溫度分布 多孔介質(zhì) 均質(zhì)流體 同步測量　出處：《大連理工大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

【摘要】：碳封存(CCS, Carbon Capture and Storage)技術(shù)捕集二氧化碳、運(yùn)輸并將其封存于儲層以緩解溫室效應(yīng),特別是二氧化碳驅(qū)油技術(shù),在減少二氧化碳排放量同時增產(chǎn)原油和天然氣。本文利用磁共振成像技術(shù)測量了大體積均質(zhì)流體及多孔介質(zhì)的溫度分布特性,探討了大體積均質(zhì)流體速度溫度同步測量技術(shù),研究成果可為CO2咸水層和二氧化碳強(qiáng)化采油封存場地安全性及高效性提供依據(jù)。具體研究內(nèi)容如下：設(shè)計了測量均質(zhì)流體及多孔介質(zhì)內(nèi)部溫度分布和流體速度溫度同步測量的實驗系統(tǒng),包括磁共振成像(MRI)、液體注入排出、溫度監(jiān)控、溫度壓力控制系統(tǒng)等。該系統(tǒng)可以精確控制樣品的溫度,并使用熱電偶測量樣品的溫度及流動進(jìn)出口溫度,從而驗證MRI溫度測量精度,該實驗平臺可用于確定均質(zhì)流體和多孔介質(zhì)的速度溫度分布。利用磁共振成像技術(shù),標(biāo)定了純水、飽和二氧化碳水及正癸烷大體積均質(zhì)樣品的縱向弛豫時間、縱向平衡磁化強(qiáng)度及自擴(kuò)散系數(shù)與溫度的關(guān)系。實驗結(jié)果表明一定溫度范圍內(nèi)這三個參數(shù)均與溫度存在良好的線性關(guān)系,自擴(kuò)散系數(shù)法測量均質(zhì)流體樣品精度最高、溫度敏感度最高；而縱向弛豫時間法和縱向平衡磁化強(qiáng)度法測量均質(zhì)流體樣品溫度分布耗時較長,精度有限。隨后利用自擴(kuò)散系數(shù)法測量純水樣品冷卻過程中的溫度分布,隨著溫度梯度的減小,測得的流體溫度變化減慢且核磁管壁面溫度低于樣品中心。開發(fā)了磁共振成像同步測量流體溫度速度的技術(shù),開展了測量不同流速下流體的速度溫度實驗,獲得了不同速度分布及溫度分布圖。用FLUENT模擬同實驗條件下的速度分布及溫度分布,模擬結(jié)果表明該方法不僅可以可視化流場速度分布,而且可以獲得較高精度溫度測量結(jié)果,溫度測量誤差在2℃以內(nèi)。模擬結(jié)果與實驗測得的溫度速度場結(jié)果吻合很好。開發(fā)了多孔介質(zhì)內(nèi)流體溫度分布的測量方法,研究了多孔介質(zhì)內(nèi)飽和水的自擴(kuò)散系數(shù)、縱向弛豫時間與溫度關(guān)系特性,并用自擴(kuò)散系數(shù)法得到多孔介質(zhì)冷卻過程的降溫趨勢圖和溫度分布圖,MRI自擴(kuò)散系數(shù)法測量的溫度值與熱電偶測量值誤差基本在1℃以內(nèi),探析了多孔介質(zhì)內(nèi)溫度分布特性。本研究確立了MRI技術(shù)測量均質(zhì)流體及水飽和多孔介質(zhì)溫度分布的有效性,能準(zhǔn)確地得到儲層巖心的微觀孔隙結(jié)構(gòu)和多孔介質(zhì)模擬巖心的溫度分布,為以后詳細(xì)研究多孔介質(zhì)和均質(zhì)流體內(nèi)的傳質(zhì)傳熱特性提供了重要實驗方法和實驗手段、為二氧化碳封存的高效及安全性提供了保障。
[Abstract]:CCS (Carbon Capture and Storage) technology traps, transports and stores carbon dioxide in reservoirs to ease Greenhouse Effect, especially carbon dioxide displacement. In this paper, the temperature distribution characteristics of large volume homogeneous fluid and porous medium are measured by magnetic resonance imaging, and the simultaneous measurement technology of velocity temperature of large volume homogeneous fluid is discussed. The research results can provide the basis for the safety and efficiency of CO2 salt water layer and CO2 enhanced oil recovery storage site. The specific contents of the study are as follows: the temperature distribution and velocity temperature in homogeneous fluid and porous media are measured. An experimental system for synchronous measurement, This system can accurately control the temperature of the sample, and use thermocouple to measure the temperature of the sample and the inlet and outlet temperature of the flow. The experimental platform can be used to determine the velocity and temperature distribution of homogeneous fluid and porous media. The pure water is calibrated by magnetic resonance imaging. Longitudinal relaxation time of saturated carbon dioxide water and decane bulk homogenized samples, The experimental results show that there is a good linear relationship between the three parameters and temperature in a certain temperature range, and the self-diffusion coefficient method has the highest accuracy in measuring homogeneous fluid samples. The temperature distribution of homogeneous fluid samples measured by the longitudinal relaxation time method and the longitudinal equilibrium magnetization method is the highest, and the temperature distribution in the cooling process of the pure water sample is measured by the self-diffusion coefficient method. With the decrease of temperature gradient, the measured fluid temperature changes slowly and the wall temperature of nuclear magnetic tube is lower than the center of the sample. A technique for simultaneous measurement of fluid temperature velocity by magnetic resonance imaging (MRI) is developed. In this paper, the velocity and temperature distribution of fluid at different velocity is measured, and the velocity distribution and temperature distribution are obtained. The velocity distribution and temperature distribution under the same experimental conditions are simulated by FLUENT. The simulation results show that this method can not only visualize the velocity distribution of the flow field, but also obtain high precision temperature measurement results. The temperature measurement error is less than 2 鈩，

本文編號：1551342