交叉式多股流板翅式换热器数值研究

借鉴顺逆式板翅式换热器研究成果,分析了交叉式多股流板翅式换热器传热机理,建立了基于有限容积法的多股流板翅式换热器传热数学模型,经过合理假设将翅片间距与单元格尺寸独立,拓展了前人数学模型适用范围.同时,以机载交叉式3股流板翅式换热器为例,对单元格尺寸选取进行了探讨,对同一通道单元格内流体流动横向传热进行了分析,证明了忽略流动横向传热的可行性,从而在保证精度不变条件下提高了计算效率;并在流体变入口参数条件下进行试验,对数值计算方法进行验证,通过与试验数据对比,理论计算误差小于7.9%,证明了数值计算方法的合理性. 

Numerical study on cross-type multi-stream plate-fin heat exchanger

Heat transfer mechanism of cross-type multi-stream plate-fin heat exchanger (MPFHE) was analyzed and the mathematical model by finite volume method was established based on the research of parallel-counter type MPFHE, and then the distance between fins was separated with cell size by reasonable assumption, expanding the application of former mathematical model. Besides, discussion about choice of cell size was conducted for the airborne cross-type three-stream plate-fin heat exchanger; while the analysis of transverse heat transfer of flow within a cell on the same channel was applied to demonstrate the possibility of ignoring the transverse heat transfer in this direction, so as to increase calculation efficiency under the constant computational accuracy; moreover, experiment of different inlet flow rates or temperatures was carried out to verify the veracity of numerical method. The calculation uncertainty is less than 7.9% compared with the test record, thus proving the rationality of numerical method.