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121.
The time series of heat-transfer film coefficient for an evaporator with a vapor-liquid two-phase boiling flow were forecasted by the chaotic prediction or the local nonlinear short-term prediction. The forecasting method was based on the phase space reconstruction theory and a mathematic model in the form of datum driving had been developed to carry out the prediction. The signals of heat-transfer film coefficients predicted by this method were compared with those obtained from the experimental measurements. Different from the previous work, the comparisons in this work were done both from the point of view of the time trajectory and from the point of view of macroscopic or general characters. Besides the time-averaged statistics characteristics, such as the average value, average deviation and standard deviation, the power spectrum, phase plane map and chaotic invariants including the correlation dimension and Kolmogorov entropy had been calculated and been compared for the time series obtained both from the experimental measurement and from the forecast. The comparison for each parameter between the value calculated from the time series measured and that estimated from the time series forecasted by the chaotic forecast method shows satisfactory agreement. The limited length in time with an accuracy prediction indicates that the system is chaotic. The agreement of the comparison of the general parameter indicates that the chaotic prediction is effective for the estimations of the heat transfer characteristics of the two-phase flow boiling system and that the chaotic prediction method may be a potential tool for the effective thermo-fluid control for such evaporators. 相似文献
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《矿业科学技术学报(英文版)》2017,27(4):651-655
Heat management must be maintained within the mine working environment to minimize stress on equipment and personnel. The issue is a growing concern as mines continue to expand in size, depth and infrastructure. Heat management is a concern as it relates to both heat sensitive equipment and more importantly the health and safety of the workers found within the mine. Proper application of engineering protocols and work practice controls will have a direct impact on the health and safety of workers and increased productivity. Using continuous monitoring stations placed in strategic locations throughout the mine to capture the environmental conditions, various strategies can be used in the planning and prevention of potential hazard exposure. Economic analysis is used to select the most feasible strategy for heat stress control. This paper presents a step by step methodology that may be considered by ventilation specialists to effectively implement a heat management control system. A case study based on a detailed heat management assessment conducted for a potash mine in Saskatchewan, Canada is presented. 相似文献
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为了对比纳米流体在内置扭带管中的强化传热效果,建立了以Cu-水纳米流体和水为传热介质的内置扭带强化换热管的管式换热器物理模型,采用RNG k-ε进行数值模拟研究,并与实验结果对比,得到了内置扭带换热管流体流动的速度、温度、湍流强度场的分布规律及特性。比较了两种质量分数的纳米流体与水在六种不同扭转比的扭带换热管中和两种不同材质的内置扭带分别对强化传热的影响。结果表明,以Cu-水纳米流体为工质的内置扭带管的换热效果明显优于纯水;质量分数为0.8%的Cu-水纳米流体换热效果优于0.5%的Cu-水纳米流体,扭转比越小,则换热效果越好,质量分数为0.5%的Cu-水纳米流体在扭转比为2.5的内置扭带管中相对于水在光管的强化幅度为0.51;铜制扭带的换热效果优于铝制扭带。 相似文献
125.
介质热管锅炉成套供热系统是哈工大的科研成果,属于国家级新技术产品.该项技术的成功引进和应用,填补了我市供热领域的一项空白.现已成功投入运行100余台套,供热面积20万m2.该系统的突出特点是:1、节电、节水、节煤;2、抗寒冻;3、系统简单、启动快;供热惰性少,供热均匀,传热效率高,4、投资少,使用方便;安全可靠.特别适用于中、小学校、影剧院、生产厂房等间歇式供热的用户.该技术是现代锅炉技术和热管技术结合而创立的新一代供热系统.其推广和应用有广泛的发展前景. 相似文献
126.
邓军 《江汉石油职工大学学报》2014,(2):59-61
针对坪北经理部储油罐人工检尺装置(以下简称量油管)在实际使用过程中出现的问题,对原有的量油管进行优化改造,成功推广应用新的量油管。改造后的量油管在使用过程中真实的反映储油罐中原油含水率、界位、液位的实际情况,以及储油罐中原油的实际品质,取得了较好的使用效果。 相似文献
127.
Silica gel or zeolites AlPO-5 and SAPO-34 are recommended as adsorbents in water-driven heat pumps because of their selective water uptake. Secondary energy, like solar energy, can be used for regeneration of loaded adsorbers. In case of the availability of only low energy levels, the use of dealuminated Y zeolite (DAY) is the better choice because of the infinitely variation of its hydrophilic properties by tailoring of the framework Si/Al ratio. Actual data on the hydrothermal stability of DAY are lacking. Thus, we report on the long-term behavior of DAY zeolites with different Si/Al ratios. 相似文献
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