Solena燃料公司在英国选择牛津催化剂微通道费托合成技术

总部设在美国的Solena燃料公司于2012年7月上旬宣布,在英国开发生物质制油(BTL)项目将选用牛津催化剂集团公司的微通道费托合成(FT)技术。Fluor公司代表Solena对现有技术进行正式评估后,决定选择牛津催化剂集团FT技术作为Solena燃料公司绿天伦敦(GreenSky London)项目的唯一供应商。     

Multiphysics simulation of a novel concept of MEMS-based solid propellant thruster for space propulsion

This work analyzes a novel MEMS-based architecture of submillimeter size thruster for the propulsion of small spacecrafts, addressing its preliminary characterization of performance. The architecture of microthruster comprises a setup of miniaturized channels surrounding the solid-propellant reservoir filled up with a high-energetic polymer. These channels guide the hot gases from the combustion region towards the nozzle entrance located at the opposite side of the thruster. Numerical simulations of the transient response of the combustion gases and wafer heating in thruster firings have been conducted with FLUENT under a multiphysics modelling that fully couples the gas and solid parts involved. The approach includes the gas-wafer and gas-polymer thermal exchange, burnback of the polymer with a simplified non-reacting gas pyrolysis model at its front, and a slip-model inside the nozzle portion to incorporate the effect of gas-surface and rarefaction onto the gas expansion. Besides, accurate characterization of thruster operation requires the inclusion of the receding front of the polymer and heat transfer in the moving gas-solid interfaces. The study stresses the improvement attained in thermal management by the inclusion of lateral micro-channels in the device. In particular, the temperature maps reveal the significant dependence of the thermal loss on the instantaneous surface of the reservoir wall exposed to the heat flux of hot gases. Specifically, the simulations stress the benefit of implementing such a pattern of micro-channels connecting the exit of the combustion reservoir with the nozzle. The results prove that hot gases flowing along the micro-channels exert a sealing action upon the heat flux at the reservoir wall and partly mitigate the overall thermal loss at the inner-wall vicinity during the burnback. The analysis shows that propellant decomposition rate is accelerated due to surface preheating and it suggests that a delay of the flame extinction into the reservoir is possible. The simulated operation of the thruster concept shows encouraging performance.     

争议煤炭运输第四通道

一条输煤管道的设计完成,引发了第四种运输方式的大讨论,不缺技术,也不缺资金的中国能否将这种方式商业化推广？     

300MW汽轮机排汽通道出口速度分布对凝汽器传热端差的影响

介绍了300MW汽轮机组排汽通道出口速度分布对凝汽器传热端差的影响.通过对模型吹风实验,测出不同状态下的流场分布.理论分析和计算表明排汽通道出口速度分布不均匀会使凝汽器传热端差变大.通过改造排汽通道的结构,可使排汽通道出口速度分布均匀,因此可以提高电厂运行的经济性和安全性.     

CNG地下储气井安全控制装置设计

针对目前国内没有用于CNG汽车的高压气地下储气井安全控制装置的现状，设计出了一套CNG汽车高压气地下储气井安全控制装置，它由地下储气井、节能蓄能器、液压泵、微机控制装置、传感器等组成。当地面出现火灾、地震及其它不可预见的事故，使储气井地面设备遭到破坏的紧急情况时，能自动及时关闭储气井与地面的通道，增强高压气地下储气井的安全性和可靠性，大大减少城市环境污染，为CNG汽车的推广应用提供进一步的技术支持。     

地层测试器施工工艺问题讨论

SFT地层测试器在施工过程中容易出现通道堵塞的情况，影响测井成功率。文章结合工作原理，对这一问题的原因进行了分析，提出了一些切实可行的解决方案以及其它需要注意的施工工艺问题。     

Research on performance of centrifugal pump with different-type open impeller

To investigate the influence of impeller type on the performance and inner flow of centrifugal pump, the numeri- cal simulation and experimental research were carried out on the same centrifugal pump with straight-blade and curved-blade open impeller. Based on SIMPLEC algorithm, time-averaged N-S equation and the standard k-e turbulence model, the numerical results are obtained. The pressure distribution in the different type impellers is uniform, while the low pressure area in straight-blade inlet is larger. The vortexes in the passage of impeller exist in both cases. Relative to curved-blade impeller, there are larger vortexes in most of the flow passages except the passage near the tongue in straight-blade impeller. Also some small backflow regions are found at the blade inlet of two impellers. The characteristic curves achieved by numerical simulation basieaUy agree with those by experiment, and straight-blade open impeller centrifugal pump has a better hydraulic performance.     

光伏散热扁管内部流场的数值模拟

本文将换热器用扁管应用到光伏电池散热中,将光伏电池散失的热量用于提高扁管内流体的温度,实现能源的高效利用.采用fluent软件,对设置在光伏电池板背面以水为介质的扁管通道进行了数值模拟,获得了内部的流场和温度场,并分析了入口流速、入口水温、有无隔板及隔板数目对出口水温的影响,结果表明适当降低入口流速和入口水温、在通道内设置隔板或者增加隔板数目,均可提高出口水温.     

“北极能源通道”进行时

一条冰封已久的航道已经开启,一场开发北极大陆架的热潮已经来临,于是,一条新的能源贸易通道正在悄悄成型之中。     

七棒束内超临界流体流动传热的数值分析

在7棒束内超临界氟利昂流体传热试验数据的基础上,采用ω类湍流模型SST和RSO以及ε类湍流模型RNG和SSG对三组典型工况进行了数值计算.结果表明:近壁面区域采用低雷诺数模型处理的ω类模型能定性捕捉到壁面的局部传热弱化现象,而壁面函数法的处理方式不能预测到此类现象;受7棒束非对称热边界条件和强浮力的影响,棒束不同通道内流率分布存在强烈的不均匀性,中心棒和周边加热棒的传热特性存在显著差异.为了准确预测棒束内超临界流体的传热特性特别是典型传热弱化现象,应重点完善湍流模型的近壁面区域处理方式.