查询词典 convection heat transfer

The thesis can be divided into five parts as follows: First, the structural characteristics of finned-pipe evaporator are analyzed. After selecting suitable microelement controller, the heat-transfer and mass-transfer processes are analyzed for every microelement under the conditions of dryness, wetness and frostiness. Based on previous equations, some parameters of frostiness are confirmed and the frost-growing model is set up under frost condition. Some hypotheses are postulated and with the help of the equation of mass-conservation, energy-conservation and momentum-conservation, the evaporation model which fits in the dynamic simulation is built, which set a solid foundation for system simulation. Second, the starting and stopping behaviors under disturbed condition are analyzed and calculated by using the dynamic concentrative parameter model, which gives some advice to better prescribe refrigeration system and set theoretic foundation for carrying out automatic control of refrigeration system. Third, the normal running process is analyzed and calculated by means of rational matching theory, which gives some advice on how to better understand the parameter change under steady state and the affection of inlet-parameter on evaporator. Fourth, the simulation software with dynamic characteristic is designed, which can be applied to calculate thernio-parameter of cryogen, air humidity and frost thickness under different initial and boundary conditions, and to carry out dynamic simulation under conditions of dryness, wetness and frostiness, at the same time, to achieve detection and simulation at any stage from starting to stopping.

本文的主要内容如下：1对翅片管蒸发器结构特点进行分析，选取适当的微元控制体，就干、湿和霜工况下对每个微元分别进行传热传质分析，基于经验关系式确定霜的有关参数，对于霜工况下的霜生长建立模型，经适当假设，运用质量守恒、能量守恒和动量守恒方程建立适合动态仿真的蒸发器数学模型，为系统仿真奠定基础； 2对蒸发在大扰动下的开、停机过程，运用动态集中参数模型进行分析和计算，为更好地描述制冷系统运行的全过程奠定基础，同时也为制冷系统实现自动控制提供一定的理论基础； 3对蒸发器正常运行过程，运用动态分布参数和参数间定量耦合的观点来分析和计算，为更好地了解稳态工况下各点参数的变化情况及各入口参数对蒸发器动态特性的影响即蒸发器性能对各参数变化的敏感性； 4编写翅片管蒸发器动态特性仿真计算程序，可以计算不同边界条件和初始条件下的制冷剂热力参数、空气温湿度和霜厚度分布场，实现对翅片管蒸发器在干、湿和霜工况下的动态仿真。

In order to get higher energy transfer rate and optimumcomprehensive performance of the heat transfer system, the best matching geometrical parameters of W-shaped single eddying tube are sought by optimize design.

通过对W形旋流管的优化设计，使旋流管的结构参数得到合理匹配，以达到更高的能量传递速率，并使换热系统的综合性能最优。

This model was used to analysis the temperature profiles and the relative relationship of latent heat transfer and mass transfer.

并利用该模型，定量分析了不同壁面热流密度、液相进口温度和空气速度下竖直板面的温度分布、气-液界面处潜热和显热换热量的相对关系。

With aim to develop this advanced gasification process, a great deal of experiments have been made on the technique of solids transfer between parallel fluidized beds, which is commonly regarded as the key problem concerning the success of the whole system, and detail theoretic investigation into the gas-solid 2-phase flow characteristics and heat transfer in fluidized-bed reactors are also made.

本文研究的目的在于研制和发展并列流化床煤气化这一先进的工艺过程，对流化床间颗粒循环这一关键技术进行了大量的实验研究，并对流化床反应器中气固两相流动特性和主要传热过程进行了理论探讨。

Based on the theory of heat-transfer and mass-transfer, a set of mathematical model for combustion of pulverized coal has been derived.

这和烟煤具有较好的燃烧性一致。

Viscous flow patterns are set up in the motor, increasing heat transfer to the propellant surface through greater mass transfer.

粘性流场的模式成立，在电机，增加传热推进剂表面通过更大的传质。

English Outline Describes the classification and characteristics of biochemical reactions, major metabolic pathways; biochemical thermodynamics, biokinetics, immobilization technology, bioreactor construction, experimental design, mass transfer, heat transfer, and flow pattern; mathematical modeling, computer simulation, and optimization; the classification of reactors, aerobic and anaerobic, their operational characteristics and applications.

Chinese Outline 探讨生物化学反应种类及其特性，主要代谢路径；生物热力学、生物动力学、酵素特性探讨与酵素动力学，固定化技术、生物反应器之组装、实验设计、反应器内质传、热传及流动型态解析；数学模式，电脑模拟及最适化；简介反应器种类：好氧及厌氧反应器，其操作特性与应用。

The integrated mathematic model of solidification is then established, which includes heat transfer, solute transfer, liquid flow and the movement of equiaxial crystals in solidification process.

本文通过两相流理论建立了等轴晶在对流金属液中移动的非稳态数学模型，推导了求解等轴晶在非稳态、非均匀液相流场中非稳态移动的数值表达式，并进一步推导了描述等轴晶在凝固过程中迁移、堆积规律的局部堆积方程式。

A detailed description of the heat transfer and mass transfer during ammonia-water bubble absorption in air-cooled vertical finned tube is presented.

详细描述了垂直风冷翅片管吸收器中氨水鼓泡吸收的传热和传质过程。

Methods of forming a pattern of filled dielectric material on a substrate by thermal transfer processes are disclosed comprising exposing to heat a thermally imageable donor element comprising a substrate and a transfer layer of dielectric material.

公开了通过热转移工艺在基底上形成填充介电材料图案的方法，包括将包含基底和介电材料转移层的热成像供体元件向热暴露。

You can snipe the second and third union leaders from this position.

您可以鹬第二和第三工会领袖从这一立场出发。

Aiming at the currently shortage of XML streams quality detecting, this paper proposes a new forecasting method of XML streams quality by least squares support vector machines, which is used the method of XML keys' vector matrix as windows, and vector product wavelet transform to multilevel decompose and refactor the XML streams series, that can fulfill real-time checking demand of XML quality, and ensure constraint, consist- ency and integrality. For even more adapting net load, it proposes a control strategy by weight and adaptive adjustment to ensure XML streams quality.

针对当前XML数据流质量检测存在的不足，提出构建XML键的矢量矩阵作为窗口，利用矢量积小波变换多级分解与重构XML数据流，再结合最小二乘支持向量机对XML数据流质量进行预测的一种方法，满足XML数据流质量重构时实时检测的要求，保证XML数据的约束性、一致性与完整性；为了更好的适应网络负载，采取加权与自适应窗口调整等调度策略充分保证XML数据流的质量检测。