共查询到18条相似文献,搜索用时 78 毫秒
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研究将一种可改善气固化学热泵循环性能的周期性强制流向变换的动态操作引入双反应器氯化钙─甲醇化学热泵系统,在文献[3~5]的基本循环过程研究的基础上,建立了描述这类换向循环过程的动态分布参数模型。由此通过数值模拟分析了固相床层内的热波现象。对不同换向操作方式的研究结果表明:周期反向操作确实可以改善常规的同向操作的循环性能,而半周期反向操作则比常规的性能还要差。 相似文献
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氯化钙-甲醇化学热泵循环特性的模拟与分析 总被引:5,自引:0,他引:5
本文应用模型化方法研究了装料量为3 kg氯化钙的实验室规模氯化钙-甲醇化学热泵的循环特性,结果表明:热泵系统的供热、制冷性能系数可分别达到1.55和0.57左右。系统的性能对反应器的传热参数及其热容量非常敏感。采用强化反应器传热和降低其热质的方法,可有效地提高系统的性能系数,增大系统的供热、制冷能力。 相似文献
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连续回热型气-固化学热泵制冷系统的操作优化 总被引:3,自引:0,他引:3
对连续回热型气-固化学热泵制冷系统,以制冷功率最大为优化目标,通过建立数学模型及模拟计算,考察了平均制冷功率随循环时间的变化,并确定最优循环时间。此外,还考察系统在一个最优循环周期各个阶段的温度动态以及不同操作条件对最优循环时间和最优制冷功率的影响。文中介绍的操作优化方法对类似的热泵制冷系统有一定的实用参考价值。 相似文献
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采用柱状阳离子交换树脂S-54作催化剂研究了叔丁醇脱水的反应精馏过程.在实验基础上建立了该过程的数学模型,采用超松弛法,并以动态方程逼近计算稳态过程对模型进行了求解,计算结果与实验结果吻合良好.在以上研究基础上考察了不同进料流量、进料组成、进料位置以及不同回流比等对反应转化率的影响,进行了上述工艺操作参数的模拟寻优,得到以下结论:反应精馏操作实现了水从反应体系中的有效移除,减小了水对反应的阻害作用,使叔丁醇接近完全分解;同时改变操作压力可以适用不同温度热源的热量回收要求. 相似文献
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0 引言 兖矿国宏化工有限责任公司500kt/a甲醇项目低温甲醇洗装置由德国鲁奇公司承担基础设计,中国五环化学工程公司承担详细设计,设计处理气量为218000m3/h. 相似文献
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我国能源结构决定了以煤为主的甲醇生产路线。传统煤制甲醇过程主要存在过程能量效率低、CO2捕集能耗高等问题。本文提出了一种化学链空分联合化学链制氢的煤制甲醇新过程,以降低能耗、二氧化碳排放及提高能源效率。化学链空分技术的集成可以替代传统煤制甲醇过程的空气分离单元,并在一定程度上降低能耗。化学链制氢技术的集成,一方面可以替代水煤气变换装置,并且可以极大程度降低二氧化碳捕集能耗;另一方面,化学链制氢技术还可生产用于调整合成气氢与碳比的氢。本文对新过程的核心单元进行了参数优化以及全流程的模拟,基于模拟对新过程的性能进行了分析,结果表明新过程与传统的煤制甲醇过程相比,空分和二氧化碳捕集能耗分别降低了41%和89%。同时,新过程的能量效率提高了18%,二氧化碳排放量降低了45%。 相似文献
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S. Karthikeyan 《电镀与涂饰》2008,27(10)
化学镀镍是一个采用合适的还原剂(如次磷酸钠)使镍离子在某催化界面上可控地自催化还原的过程,所生成的膜层附着良好,应用广泛.以次磷酸盐作为还原剂时,化学镀镍的沉积速率通常低于20 μm/h,故研究了在有少量硫脲或其衍生物作为加速剂的条件下,次磷酸盐体系中镍的化学沉积过程.通过动电位阴,阳极极化和循环伏安研究,评价了镀覆过程中各种加速剂的性能.结果表明,所研究的硫化物都有明显的阳极去极化作用.各种加速剂性能的优劣顺序为:甲基硫脲>N,Nr-乙烯硫脲>烯丙基硫脲>乙酰硫脲>对甲苯基硫脲>硫脲>二苯基硫脲.此外,氯基硫脲的性能优于巯基琥珀酸. 相似文献
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Polypropylene (PP) flame retardant composites filled with aluminum hydroxide (Al(OH)3), magnesium hydroxide (Mg(OH)2) as well as zinc borate (ZB) were prepared with a twin‐screw extruder. The melt volume flow rate (MVR) and density of the composites were measured by means of a melt flow rate instrument under experimental conditions with temperature of 180°C and load varying from 2.16 to 5 kg, to identify the effects of the particle size and content. The results showed that MVR of the composites decreased with an increase of the filler weigh fraction (?f) when ?f was more than 10 phr. The MVR decreased first and then increased with an increase of the filler diameter (d). The melt density (ρm) of the composites increased linearly with an increase of ?f and decreased linearly with the increase of d. In addition, the ρm increased with an increase of load. Under the same experimental conditions, the MVR decreased slightly while the ρm increased somewhat with addition of ZB for the PP/Al(OH)3/Mg(OH)2 composite systems. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 相似文献
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氢氧化铝和氢氧化锶复合粉末的制备及热处理 总被引:1,自引:0,他引:1
采用活化铝-锶合金粉末水解反应制备氢氧化铝和氢氧化锶复合粉末,并在700℃下进行热处理,利用XRD,SEM,BET和TG—DTG等分析技术对复合粉末结构、性能及热处理进行研究。结果表明,铝-锶合金粉末水解反应产物为氢氧化铝和氢氧化锶的复合粉末,微观形貌为1~3μm片状小颗粒叠加的团聚颗粒,BET比表面积较大。达到45.2m^2/g。TG—DTG结果显示,在70~190℃,八水氢氧化锶中8个结晶水脱水,在190~650℃,氢氧化铝和氢氧化锶热分解。经700℃下热处理1h后,其相组成、微观形貌、BET比表面积都将发生较大的变化。 相似文献
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The operability of a thermally driven chemical heat pump using the magnesium oxide/water reaction system was demonstrated experimentally. The heat pump system, consisting of a packed bed reactor and a water reservoir, was operated thermally with no mechanical work. The thermal output performance of the reactor bed was measured under pressures between SO and 202 kPa. The heat pump was expected to be applicable as a heat storage system for high efficiency energy utilization in cogeneration. 相似文献
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制备了PP/Al(OH)_3/Mg(OH)_2阻燃复合材料,利用熔体流动速率仪测定了复合材料的熔体体积流动速率(MVR),并计算出其密度。结果表明:MVR随着阻燃剂质量分数的增加而减小,随着阻燃剂粒径的增加先降后升;复合材料密度随阻燃剂用量的增加呈近似线性增加,随阻燃剂粒径的增加呈近似线性降低,随着载荷的增加而提高。 相似文献
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Monodispersed Cu2(OH)3Cl nanoplatelets, Cu(OH)2 nanowires, CuO nanoparticles and nanoribbons with a spherical morphology were synthesized using hydrothermal and heat-treatment reactions, and their H2 storage characteristics were examined. The Cu2(OH)3Cl nanoplatelets particles formed immediately after mixing the reactant, which subsequently formed larger uniform spherical particles in the submicron range. This procedure highlights a practical strategy for producing spherical Cu(OH)2 and CuO materials consisting of monodispersed nanocrystals. The spherical aggregates of Cu2(OH)3Cl nanoplatelets heat-treated at 473 K could reversibly store up to 2.35 wt.% H2 at 38 bar and 293 K. 相似文献
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Polymeric materials are used extensively, but their applications are limited because many of them are flammable. Therefore ways to make them flame retardant have received much attention. In this work, polypropylene (PP) was used as the matrix resin, aluminium hydroxide (Al(OH)3) and magnesium hydroxide (Mg(OH)2) as flame‐retardant additives and zinc borate (ZB) as a flame‐retardant synergist. PP/Al(OH)3/Mg(OH)2 and PP/Al(OH)3/Mg(OH)2/ZB flame‐retardant composites were prepared with a twin‐screw extruder. The flame‐retardant properties, i.e. oxygen index (OI), burning velocity and smoke density, of the composites were measured. The results showed that OI increased with an increase of the filler content and decreased with an increase of the filler particle diameter. The burning velocity decreased with an increase of the filler content, while it first increased and then decreased with an increase of the filler particle diameter. The smoke density decreased with an increase of the filler content and increased with an increase of the filler particle diameter. There was a flame‐retardant synergy between Al(OH)3/Mg(OH)2 and ZB in the composites, and the smoke suppression effect was marked when ZB was added. Copyright © 2009 Society of Chemical Industry 相似文献
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