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31.
32.
羟乙基乙二胺(AEE)水溶液的CO2循环吸收量高(1.2molCO2/molAEE),吸收速度快,稳定性好,但解吸速度慢、解吸量少(0.8mol CO2/mol AEE)是限制该技术广泛应用的主要原因。本文通过向AEE水溶液中添加质量分数为0.05%~0.20%的改性氧化钛(TiO2-MWCNT和TiO2-OH)强化AEE的解吸能力。CO2循环吸收(40℃)-解吸(120℃)实验结果表明改性氧化钛的添加比氧化钛强化CO2解吸效果更好,强化顺序为TiO2-MWCNT>TiO2-OH;其对应的最大解吸速率分别为0.093L/min(质量分数0.15%)和0.083L/min(质量分数0.20%),相对于AEE水溶液,分别提高了32.9%和18.6%;其对应的最大解吸量分别为0.92molCO2/molAEE(质量分数0.15%)和0.88molCO2/molAEE(质量分数0.20%),分别提高了12.2%和9.7%;其对应的CO2循环吸收量分别是0.95molCO2/molAEE(质量分数0.15%)和0.89molCO2/molAEE(质量分数0.15%),分别提高了18.75%和11.25%;5次循环吸收解吸实验结果表明改性氧化钛强化CO2解吸效果稳定,具有较强的化学稳定性。对反应后的改性氧化钛进行XRD、BET、FTIR和SEM表征,结果表明改性氧化钛具有较强的结构稳定性。TiO2-MWCNT和TiO2-OH在促进有机胺溶液解吸CO2方面具有一定的工业应用潜力。 相似文献
33.
设计了一种内插式真空管热水集热器,通过对其能量转换、传输特性研究,建立了内插式真空管集热器的热特性分析模型,并对不同设计参数和气候条件对内插式真空管热特性的影响进行了分析。结果表明,设计的集热器理论热效率最大可达79.5%,但其受环境温度、集热器工作温度等影响较大。此外,设计了由14只内插式真空管组成的太阳能热水器,采用迟滞算法将热水温度控制在50~55℃,实验结果表明,样机系统的日热效率可达55.0%,样机输出热水近120 kg,具有较好的实用价值。 相似文献
34.
The Caputo and Caputo–Fabrizio derivative are applied to study a second‐grade nanofluid over a vertical plate. A comparative analysis is presented to study the unsteady free convection of a second‐grade nanofluid with a new time–space fractional heat conduction. The governing equations with mixed time–space fractional derivatives are non‐dimensionalized and solved numerically, and a comparison between the Caputo and the Caputo–Fabrizio models is made. It is found that the temperature is higher for the Caputo–Fabrizio fractional model than the Caputo model, but the higher velocity only exists near the vertical plate for the Caputo–Fabrizio model than the Caputo model. Moreover, the velocity for the Caputo model will exceed the Caputo–Fabrizio model as y evolves. 相似文献
35.
Mehdi Noorbakhsh Mohsen Pourfallah Seyed S. M. Ajarostaghi Mohammad Zaboli 《亚洲传热研究》2020,49(8):4678-4703
Heat exchangers are extensively used in various industries. In this study, the impact of geometric and flow parameters on the performance of a shell and double helical coil heat exchanger is studied numerically. The investigated geometric parameters include external coil pitch, internal coil pitch, internal coil diameter, and coil diameter. The influences of considered geometrical parameters are analyzed on the output temperature of the hot and cold fluid, convective heat transfer coefficient, pressure drop, and average Nusselt number. Water is considered as working fluid in both shell and tube. As an innovation, double helical coils are used instead of one in the heat exchanger. To compare the obtained results accurately, in each section, the heat transfer area (coil outer surface) is kept constant in all models. The results show that the geometrical parameters of double helical coils significantly affect the heat transfer rate. 相似文献
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37.
Through a combined computational fluid dynamics and discrete element method approach, the effect of the operating parameters on the hydrodynamics and heat‐transfer properties of gas‐solid two‐phase flows in a spouted bed are extensively investigated. Considering the high velocity in the fountain region, gas turbulence is resolved by employing the large‐eddy simulation. The rolling friction model is adopted for more precise predictions of solid behavior near the wall. Subsequently, the gas‐solid flow patterns, gas‐solid velocities, and temperature evolution are investigated. Moreover, different operating conditions and geometry configurations are evaluated with respect to heat‐transfer performance. The results provide a fundamental understanding of heat‐transfer mechanisms in spouted beds. 相似文献
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39.
In this paper, the nonreciprocal properties of a novel kind of 1D magnetized plasma photonic crystals(MPPCs) with the Fibonacci sequence are investigated. The isolation of the proposed 1D MPPCs is also used to analyze the nonreciprocal properties. Compared to the conventional 1D MPPCs with periodic structure, the nonreciprocal performance can be significantly improved.The effects of several parameters of the proposed 1D MPPCs on the nonreciprocal properties are studied by the transfer matrix method, which includes the incident angle, order of the Fibonacci sequence, plasma frequency, plasma cyclotron frequency and plasma filling factor. The obtained results show that the nonreciprocal propagation properties can be improved by increasing the values of the plasma cyclotron frequency and incident angle, but they will worsen by blindly increasing the order of the Fibonacci sequence, plasma frequency and filling factor of plasma.The peaks of transmittance also are obviously reduced. In addition, the value of isolation will increase with increasing the incident angle, order of Fibonacci sequence, plasma frequency and plasma filling factor. However, when the plasma cyclotron frequency is increased, the value of isolation will be increased at lower frequencies, but is almost unchanged at higher frequencies. 相似文献
40.
Abdulaziz Ali Alghamdi Abdulillah Al-Soulami Wassem Sharaf Saeed Abdel-Basit Al-Odayni Abdelhabib Elsamlali Ahmed Abdulaziz Al-Owaais 《国际聚合物材料杂志》2019,68(5):229-242
A series of poly(acrylic acid-co-methylvinylketone–graft–sulfamethoxazole)(AVMDS) species was synthesized for drug carrier applications. The synthesis involved two steps: copolymerization of acrylic acid(AA) with methyl vinyl ketone(MVK) through the free radical route and subsequent grafting of the sulfamethoxazole (SMX) onto the copolymer via the Schiff base reaction of the primary amine of SMX with the carbonyl groups of the MVK units. The structures and properties of the materials were characterized by nuclear magnetic resonance(NMR), X-ray diffraction(XRD), differential scanning calorimetry(DSC), and scanning electronic microscopy (SEM). An in-vitro cytotoxicity test of the drug-carrier systems via MTT assay revealed no significant cytotoxic effect at concentrations up to 100?µg?·?ml?1. The dynamic release of SMX from these systems through a retro-imidation reaction (inverse Schiff base reaction) was investigated in depth, where the diffusion through the polymer matrix, the enhancement of the water solubility of SMX, the influence of the initial drug concentration, the pH of the medium, and the effect of the degree of swelling of the polymer matrix on the release dynamics were evaluated. The AVMGS4 and AVMGS1 drug carrier systems containing 3.58 and 1.18?wt% of SMX were the best performing systems. 相似文献