板壳式换热器波纹倾角对换热和阻力性能影响

研究了波纹倾角（α=45°，60°，75°）对板壳式换热器单流道内单相流动与换热过程的影响，分析了波纹流道内的速度分布、湍动能分布、压力分布和温度分布；基于范宁摩擦阻力因子f和Nu与Re的关系，提出了板壳式换热器不同波纹倾角下换热特性和流动阻力特性的预测关联式；通过计算不同波纹倾角下的综合性能评价指标（performance evaluation criteria，PEC）和面积质量因子（j/f）综合评价了流动与换热性能。结果表明：波纹倾角是影响圆形板间流体流动形态的因素之一，随着波纹倾角增大，会出现“十字交叉流”向“曲折流”转变；所提出的关联式能够很好地预测板壳式换热器内阻力与换热性能，阻力特性偏差在±14%范围内，换热特性偏差在±7%范围内；α为45° 时，j/f较大，流道内阻力相对小；α为60° 时，PEC较大，流道内换热性能相对强。

INFLUENCE OF CORRUGATED INCLINATION ANGLE ON HEAT TRANSFER AND FLOW CHARACTERISTICS OF SHELL-PLATE HEAT EXCHANGER

In this paper, the numerical simulation of single-phase flow and heat transfer is carried out for the single channel of the shell-plate heat exchanger with the corrugation inclination angle α of 45°, 60° and 75°, respectively. The velocity distribution, turbulent kinetic energy distribution, pressure distribution and temperature distribution in the circular corrugated channel under different corrugation inclination angles are analyzed. Based on the relationship between fanning friction factor f, Nu and Re, empirical correlations for predicting the flow resistance and heat transfer characteristics in the shell-plate heat exchangers under the different corrugation inclination angles are proposed. The comprehensive performance of the heat exchanger is evaluated by calculating PEC and j/f under different corrugation inclination angles. Results show that the inclination angle of corrugation is one of the factors affecting the flow pattern between the circular plates. With the increase of the inclination angle of the corrugation, the flow line of fluid changes from “cross flow” to “longitudinal flow”. The proposed correlation is capable of accurately predicting the resistance and heat transfer performance of the shell-plate heat exchanger. The characteristic deviation of flow resistance and heat transfer is within the range of ±14% and ±7%, respectively. When α is 45°, the heat exchanger has a higher value of j/f , but the resistance in the flow channel is relatively small. When α is 60°, the PEC is large, which indicates the heat transfer performance in the flow channel is much more severe.