ABSTRACT

The current research presents an experimental study on heat transfer and fluid flow characteristics of a helical plate heat exchanger (HP-HEx). Helical plate with different pitches and cross sectional area of the flow channel was investigated for various fluid mass flow rates and inlet temperatures. The results show that the proposed heat exchanger performed an overall heat transfer coefficient (U) and exergy efficiency (η_ex) about 279.77 W/m².K and 60.87% respectively. Also, the HP-HEx showed effectiveness (ε) and number of transfer unit (NTU) reach about 0.694 and 1.79 respectively with pressure loss reached 202 kPa, for hot and cold fluids flow rate 0.083 kg/s and 0.07 kg/s at inlet hot and cold fluid temperature 45°C and 28°C respectively, and pitch = 56 mm. The pitch and cross sectional area of the flow channel variation can augment heat transfer rate and decrease the pressure loss. For pitch decreasing from 76 mm to 46 mm, the U, ε, NTU, η_ex, and pressure loss increase by 50.60%, 22.39%, 50.60%, 10.35%, and 20.87% respectively. Empirical general correlations were obtained from the experimental data of the present study with maximum deviations about ±16.81%, ±13.33%, ±17.73%, ±16.60% and ±15.60% for U, ε, NTU, η_ex, and pressure loss, respectively.

摘要

目前的研究对螺旋板式换热器 (HP-HEx) 的传热和流体流动特性进行了实验研究。针对各种流体质量流量和入口温度，研究了具有不同螺距和流道横截面积的螺旋板。结果表明，所提出的换热器的总传热系数 ( U ) 和火用效率 ( η _ex ) 分别约为 279.77 W/m ² .K 和 60.87%。此外，HP-HEx 显示了有效性 ( ε ) 和转移单元数 ( NTU) 分别达到约 0.694 和 1.79，压力损失达到 202 kPa，热流体和冷流体流速分别为 0.083 kg/s 和 0.07 kg/s，入口热流体和冷流体温度分别为 45°C 和 28°C，螺距 = 56毫米。流道的间距和横截面积的变化可以增加传热速率并降低压力损失。对于间距从 76 mm 减小到 46 mm，U、ε、NTU、η _ex和压力损失分别增加了 50.60%、22.39%、50.60%、10.35% 和 20.87%。从本研究的实验数据中获得经验一般相关性，U、ε、NTU、η _ex和压力损失的最大偏差约为 ±16.81%、±13.33%、±17.73%、±16.60% 和 ±15.60%，分别。