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超临界直流锅炉螺旋管圈水冷壁动态特性 总被引:1,自引:1,他引:0
从过程基本方程出发,建立了两相受热管动态特性基本方程。在此基础上,针对所研究的问题,推导了超临界直流锅炉螺旋管因水冷壁集总参数动态微分方程组,用数值积分法进行了求解。最后针对600MW超临界直流锅炉水冷壁在3种典型工况下的动态特性进行了研究,所得结果对进一步研究直流锅炉全工况动态仿真具有一定的参考意义。 相似文献
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对垂直管圈和螺旋管圈水冷套进行了结构形式、结构特点和设计事项归纳总结.并重点介绍了垂直管圈四角切圆水冷套与螺旋管圈单隔墙水冷套设计注意事项.通过对垂直管圈和螺旋管圈水冷套的结构形式和结构特点的对比,从设计和制造角度进行了分析,不同锅炉形式,不同燃烧器布置需要的水冷套结构也不同. 相似文献
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当前电网运行要求提供大功率调峰机组,而塔式螺旋管圈直流锅炉是一种适合的炉型.它具有优良的水动力特性、热偏差小、煤种适应性好、防蚀性能优越、金属耗量少及占地面积小等优点.故本文提出应发展塔式螺旋管圈直流锅炉作为我国的一种新炉型. 相似文献
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本文对亚临界参数下的控制循环锅炉,自然循环锅炉,半塔式布置螺旋管圈直流锅炉和垂直管圈的UP型直流锅炉的主要部件的制造和安装进行了简要介绍和比较。并提出上海锅炉厂目前已具有开发和制造半塔式螺旋管圈直流锅炉的能力。 相似文献
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针对余热驱动吸附式冷管单元(直径16mm,总长1020mm)制冷循环过程的变压吸/脱附特性,采用线性驱动力(LDF)模型,建立了动态的传热传质数学模型。对吸附式冷管的主要部件——吸附器和冷凝/蒸发器在加热解吸和冷却吸附不同阶段的工作过程,分别建立了耦合的动态方程。对所提出的模型进行分析和合理简化后,利用数值方法对模型进行了求解,获得了冷管单元吸附器、冷凝/蒸发器的循环工作参数的动态变化规律,计算结果与实验结果较好地吻合。为吸附式冷管单元及其组合式制冷系统进一步的优化设计和实用化的改进研究提供了重要参考。 相似文献
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M.K. Mittal Ravi Kumar Akhilesh Gupta 《International Journal of Thermal Sciences》2009,48(7):1348-1354
In the present work, a homogenous model including the metastable liquid region has been developed for the adiabatic flow of refrigerant through the spiral capillary tube. In order to develop the model, both liquid region and two phase region have been discretized into infinitesimal segments to take into account the effect of varying radius of curvature of spiral tube on the friction factor. The effect of the pitch of spiral on the mass flow rate of refrigerant and capillary tube length has been investigated. A comparison of flow characteristics of refrigerant R22 and its alternatives, i.e., R407C and R410A has been made at different operating conditions at the inlet of the capillary tube and it has been found that the flow characteristics of R22 and R407C are almost similar for a given condenser pressure and degree of subcooling at the inlet of capillary tube. 相似文献
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根据螺旋槽管的结构特点及传热特性,建立了三种不同槽口形状的螺旋槽管与光滑管换热器的三维模型。以水为工质,运用 Fluent流体分析软件,采用k-ε湍流模型,研究了三种不同槽口形状的螺旋槽管与光滑管换热器在换热过程中的速度场和温度场,得到了不同槽口形状和光滑管的壁面Nusselt数。结果表明。在相同壳程和雷诺数的情况下,螺旋槽管比光滑管的换热能力提高了6.7%-37.6%,其中三角彤槽和矩形槽螺旋槽管的换热能力提高最大,从而强化了传热。为谊产品的理论进一步研究和实验研究奠定了基础,为谊产品的设计和推广应用提供了依据。 相似文献
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Regenerative cooling with fuel as the coolant is used in the scramjet engine.In order to grasp the dynamic characteristics of engine fuel supply processes,this article studies the dynamic characteristics of hydrocarbon fue lwithin the channel.A one-dimensional dynamic model was proved,the thermal energy storage effect,fuel volume effect and chemical dynamic effect have been considered in the model,the ordinmy differential equations were solved using a 4th order Runge-Kutta method.The precision of the model was validated by three groups of experimental data.The effects of input signal,working condition,tube size on the dynamic characteristics of pressure,flow rate,temperature have been simulated.It is found that cracking reaction increased the compressibility of the fuel pyrolysis mixture and lead to longer responding time of outlet flow.The responding time of outlet flow can reach 3s when tube is 5m long which will greatly influence the conmo1 performance of the engine thrust system.Meanwhile,when the inlet flow rate appears the step change,the inlet pressure leads to overshoot,the overshoot can reach as much as 100%,such highly transient impulse will result in detrimental effect on fuel pump. 相似文献
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对相同质量流量下的光管、双层光管、带冷却结构(肋、扰流柱、凹坑、螺旋通道)的双层管等不同结构的管流动进行了流固耦合三维数值模拟,获取了固体壁温的分布特征;对各结构下,外层壁冷热侧温差、冷气温升、流动特性及综合换热效率进行了研究分析。研究结果表明:相同质量流量下,带螺旋通道双层管的外层壁冷热侧温差最小、综合换热效率最高;凹坑结构双层管与双层光管的流动及换热特性相似,流阻较小但换热效果也较差;扰流柱和肋结构双层管的流动换热特性相近,其温度分布均匀性、换热量介于双层光管和螺旋通道双层管之间,其流阻大且综合换热效率低。 相似文献
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《Applied Thermal Engineering》2001,21(11):1161-1173
A new kind of nickel alloy spiral tube has been developed, which can meet the requirements of the advanced triple-effect LiBr/H2O absorption chiller. This paper presents the experimental results of corrosion-resisting characteristics under the LiBr/H2O solution temperature which ranges from 210°C to 250°C. The tensile strength, wearability, and leaktightness of expanded tube bundles were measured. Experiments indicated that nickel alloy spiral tube bundles could withstand corrosion attack in high temperature LiBr/H2O solution, which has good characteristics of high tensile strength, wearability as well as leaktightness of expanded tube bundles. The characteristic of heat transfer will be greatly improved by enhancing treatment on the tube. 相似文献