Microchannels have attracted significant attention in the thermal management of integrated circuits due to their small size and high heat transfer efficiency.Motivated by further improving the thermal management capacity of microchan-nels in multi-core chips with a lower pressure drop penalty,a comparative investigation on four different configurations was conducted through numerical simulation for the Reynolds number(Re)ranging from 200 to 800 to analyze the comprehensive effects of filling mode and rib arrangement on the flow and heat transfer characteristics,including microchannel completely filled with aligned ribs(MCFAR),microchannel incompletely filled with aligned ribs(MIFAR),microchannel completely filled with staggered ribs(MCFSR)and microchannel incompletely filled with staggered ribs(MIFSR).Moreover,the en-tropy generation rate was used to estimate the irreversibility of flow and heat transfer based on the second law of thermodynam-ics.The performance evaluation criteria(PEC)was adopted to estimate the overall performance.The results show that the flow patterns in the MIFAR and the MIFSR are different from those in the MCFAR and the MCFSR due to the incomplete fill-ing mode,which could induce more dramatic disturbance and further break the downstream boundary layer,thus the heat transfer could be enhanced under a lower pressure drop penalty.The entropy generated by heat transfer contributes the major-ity of the total entropy generation,thus enhancing the heat transfer is a more important and effective approach in reducing the irreversibility.Among the four configurations,the microchannel MIFAR shows the best overall performance(PEC=1.76)when Re=400.
为减小水击波动,保障机场加油系统安全平稳运行,基于实际机场加油管线路由图,考虑油库并联泵机组建立机场加油系统水力仿真模型;采用节点压力法进行稳态计算,用特征线法进行瞬态计算,并在波速调整法的基础上引入惯性元件,以线程池的形式进行多线程计算,并与商业软件SPS对比.结果表明:稳态工况下节点压力偏差小于 10 kPa,瞬态工况下最大水击压力偏差小于50 kPa,验证了计算的准确性;克服了大量短管造成的计算缓慢问题,进一步提高了管网水力模拟的计算速度,能够应用于管线设计、操作培训、离线仿真等多方面,保障机场加油系统安全运行.
电场改性是一种新兴的含蜡原油改性方法,带电胶粒(胶质、沥青质)在电场作用下聚集于蜡晶表面是其主要机制.为明确带电胶粒与蜡晶的作用机制,选取电场降黏效果差异显著的两种含蜡原油,测试并分析电场作用前后油样的表观黏度、阻抗以及蜡晶晶胞参数.结果表明:电场作用后降黏效果显著的 1#原油阻抗上升,但作用温度下蜡晶晶胞参数不变,再降温至 2℃后,蜡晶晶胞参数变化显著;对于无降黏效果的 2#原油,电场作用后其阻抗不变,降温后的蜡晶晶胞参数也没有变化;电场作用下含蜡原油中的带电胶粒吸附于蜡晶表面,是电场发挥降黏效果的必要条件;部分含蜡原油中带电胶粒自缔合从而无法在电场作用下吸附于蜡晶表面,是该类原油不具有电场降黏效果的原因.
An accurate and efficient prediction of the oil ring volume in condensate gas reservoirs with high CO 2 content is very important for the development of the reservoir. However, it is difficult to detect the oil ring volume for offshore deep-water condensate gas reservoirs through large-scale drilling, and the extraction effect of CO 2 can make the oil ring volume more complex. In this study, in order to establish a machine learning model to predict the oil ring volume, the reservoir forming process of high CO 2 condensate gas reservoirs was firstly simulated through CO 2 filling experiments, and data fusion processing was conducted based on the numerical simulation results to establish a sample database, and optimize its main controlling factors through correlation analysis. The variation of oil ring volume under different formation conditions and gas cap composition was then clarified. Finally, the oil ring volume prediction training was carried out based on a support vector machine learning method, and the prediction model of the oil ring volume was established with formation conditions and main gas cap compositions as the main input and control parameters. The prediction results show that the errors between the machine learning model using a cubic kernel function with numerical simulation, experiment and actual oil ring volume are 3.43%, 5.10% and 7.21%, respectively.
渤海湾盆地胜利油区经过 60 多年开发,整装、断块油藏已处于特高含水开发阶段,含水率超过 90%,稠油油藏进入高轮次吞吐开发阶段,整体采出程度不到 40%,仍有大幅度提高采收率的潜力,需要攻关进一步提高采收率技术.针对整装油藏特高含水后期高耗水层带发育、低效水循环严重,断块油藏剩余油分布差异大、有效动用难度大,深层、薄层超稠油注汽难、热损失大,有碱复合驱油体系结垢严重,聚合物驱后油藏动态非均质性更强、剩余油更加分散以及特高含水后期套损井多、出砂加剧、精细分层注采要求高等难题,明确地质及剩余油分布特征,深化驱油机制认识,围绕整装油藏经济有效开发、断块油藏高效均衡开发、稠油油藏转方式开发、高温高盐油藏化学驱开发开展技术攻关,形成整装油藏精细流场调控技术、复杂断块油藏立体开发技术、稠油油藏热复合驱提高采收率技术、高温高盐油藏化学驱技术、特高含水期主导采油工程技术等特高含水油田提高采收率技术系列,开辟先导试验区,取得显著开发效果,实现工业化应用,支撑胜利油区持续稳产.
