【作者】 王书中；

【导师】 由世俊；

【作者基本信息】 天津大学 ， 供热供燃气通风及空调工程， 2004， 硕士

【摘要】 伴随着我国能源政策与能源结构的不断调整，天然气将成为 21 世纪能源发展与利用的重点。以燃气为主的直燃型溴化锂吸收式制冷机组在减少污染气体排放、缓解电力紧张压力、调节电力和燃气高峰负荷等方面显示出其独特的优势，发展燃气为主的直燃机将对传统的压缩式电制冷系统起到巨大的促进作用。吸收式制冷系统是换热器的组合，其中吸收器和发生器的传热传质过程都包含着二元溶液两相流动传热与传质，即使是一元溶液的蒸发器和冷凝器为了增加传热系数，减小换热面积也采取了降膜蒸发与冷凝的技术，这种复杂的热力过程使得要想建立正确描述其传热传质现象的物理数学模型非常的困难，而要实现整个吸收式制冷系统的仿真还有很多有待研究的内容。为此，本文选择了吸收器这一吸收式制冷机中最具有代表性的复杂的热力部件作为部件仿真的对象，在整理溴化锂水溶液以及纯水的物性方程的基础上，通过 Fortran 与 Matlab 混合编程，利用 Matlab 强大的矩阵计算、图形绘制及编辑功能，基于面向对象的图形用户界面（GUI）技术编制人机交互界面，实现了溴化锂吸收式制冷的可视化计算，并编制了溴化锂吸收式制冷系统工具箱，为今后的仿真设计、可视化计算提供了方便、实用的工具。与以往广泛采用的单管模型相比，本文采用了实际中应用较多的水平管束式吸收器作为研究的对象，对吸收器内二元溶液两相流动传热传质机理做了深入细致的分析，引入了润湿率 WR 这一参数来衡量实际运行中出现的管壁的不完全润湿特性，并将其作为可变参数分析它对吸收器总体性能以及蒸发器制冷能力的影响。吸收器部件仿真采用贴近实际运行状况的滴状降膜吸收模型，将每一根水平管的蒸气吸收过程分为三个区域，即：沿管壁的降膜区，管底部的液滴形成区和管间的液滴降落区。将三部分的控制微分方程组联立，分析了不同结构参数（如水平管排数、管径、管长、管轴向间距）、运行工况（如溶液质量流量、温度、浓度、冷却水质量流量、进口温度、蒸发温度等）对吸收器总体性能与蒸发器制冷量造成的影响，基于 Matlab 的仿真技术，实现了吸收器部件的仿真与可视化计算。吸收器建模与仿真的思路和方法可以扩展到其它的热力部件如发生器、蒸发器、冷凝器之中去，从而实现吸收式制冷系统的稳态/动态建模与仿真。更多还原

【Abstract】 With the frequently adjustment of energy policy and structure in China, natural gas issure to be the emphasis of energy development and utilization in 21 century. Fire-directedabsorption chiller shows the unique predominance in reducing the polluted gas exhausting,relaxing the power stress and adjusting the high load of power and natural gas supplement.So the fire-directed absorption chiller will play a promote role on traditional compressrefrigeration system. It’s very known that absorption refrigeration system is units of many heat exchangers.Absorber and generator have the complicate dual-solution two-phase flow heat and masstransfer. In order to improve the heat and mass transfer coefficient and reduce the heatexchange area of each component, even in the evaporator and condenser which onlycontains the monadic-solution flow, absorption refrigeration system utilizes the falling filmevaporation and condensing technology. This complicate thermodynamic process makesthe modeling and description of each component harder and much work to realize thesimulation of whole absorption refrigeration system. Hence, this paper chooses the mostrepresentative absorber as the component-simulation object. Based on the thermodynamicproperties function of LiBr/Water solution and pure water, through mixing programming ofFortran and Matlab, and utilizes the powerful matrix computation, graph drawing, editperformance and graphic user interface of Matlab, comes true the visualizationcomputation and develops the toolbox of absorption refrigeration which supplies thefacilitate and useful tool for the following simulation design and visualization computation. Compared with the general single-tube model, this paper takes the horizontal bundleabsorber as the research object, analyses the principal of dual-solution two-phase flow heatand mass transfer in absorber, introduces the wetting ratio to describe the incompletewetting performance and view it as the changeable parameter to explain it’s influence tototal performance of absorber and cooling capability of evaporator. The componentsimulation of absorber uses the falling and droplet model which divides the whole steamabsorption process of single tube into three zones, that is to say, falling film along the tubewall, droplet formation zone at the bottom of the tube and droplet fall between the tubes.Connecting with the three control differential function group, analyses the influence ofdifferent structure parameters such as number of horizontal tube, tube diameter, tube length,axial distance between tubes and running conditions such as solution mass flow rate,temperature, concentration, cooling water mass flow rate, inlet temperature andevaporative etc. to total performance of absorber and cooling capability of evaporator, andoriented from the simulation of Matlab, comes true the component simulation andvisualization computation of absorber. The way of modeling and simulation of absorber can also be expanded to otherthermodynamic component such as generator, evaporator and condenser, which will bebasis of the static and dynamic modeling and simulation of absorption refrigeration system.更多还原