集箱与并联管屏系统单相流体的流动特性

对沿集箱轴向各屏结构相同、而同一屏内各管圈结构不同的集箱与并联管屏系统内单相流体的流动特性的空间分布进行了理论研究 .集箱对轴向各屏与对同一屏内各管的分流和汇流分别采用连续模型和离散模型 ,屏内工质比容沿支管长度的分布引进线性变化假设 .建立了描述系统流动的封闭方程组 ,并获得了集箱及并联管屏内静压和速度分布的理论解 .在引进局部线性化假设、考虑集箱内沿程摩阻影响的条件下 ,得到了修正的理论解 .理论解及其修正解为沿集箱轴向引入、引出并联管屏系统的通解 ,其中集箱内流动参数为一维解 ,管组区流动参数为三维解 .该研究结果可直接应用于电站锅炉过热器、再热器及工业上同类型换热器的流动分析与设计 .

Single Phase Fluid Flow Characteristics in the Headers and Parallel Tube Platen Systems

The single phase fluid flow characteristics in the headers and parallel tube platen systems were studied, in which every piece of platen's structure is the same along the header axes, but each tube structure in one platen is not. Continuous and dispersed flow models are separately taken in distributing combining flow between headers to the platens which are along the header axes arrangement and to each tube in the same platen. The specific volume of working fluid is hypothesized as linear varying to the tube in length. Based on these models, the closed equations describing the flow characteristics of the systems are built. By deducing, their theoretical solutions about the pressure and flow distribution of the systems are made. By introducing the part linear hypothesis to consider the fricition in header, the corrective analytical solutions are also made. The theoretical solutions and corrective solutions are 1 demension in headers and 3 demension in space of parallel platen arrangements. These results provide an effective theoretical method for the analysis and design of the superheaters and reheaters of power boiler, and the industrial heater exchanger as well.