The enhancement of heat transfer rate in heat exchangers has been considered a major concern. In this research, the impacts of inserting twisted tapes in horizontal two-phase flow heat exchangers are discussed, and different values of vapor qualities (in the range of 0.1 to 0.7) and mass velocities (in the range of 119 to 367 kgm⁻²s⁻¹) are considered during forced convective condensation of R600a (Isobutane). The test case is a pipe made from copper with an inner diameter of 8.1 mm and a length of 1000 mm. Furthermore, three twisted tape inserts with various twist ratios (defined as the ratio of the twisted tape pitch to the test pipe inner diameter) of 4, 10, and 15 are used. The results illustrated that installing twisted tapes results in the increment of pressure drops and the rate of heat transfer in comparison to the smooth case. Furthermore, the pressure drops and heat transfer rates augment as the refrigerant mass velocity and vapor quality increase. Depending on the inserts type and operating conditions, the performance factor (a criterion to assess the performance modification compared to the primary test case) between 0.39 to 1.05 was obtained. It was also observed that there exists an optimum amount of the refrigerant mass velocity at which the performance factor is higher. Results showed that generally using twisted tapes in heat exchangers is not instrumental unless when the main concern is to improve the heat transfer rate or when the augmented power consumed by pump can be justified.

人们认为，提高热交换器中的传热速率是一个主要问题。在这项研究中，讨论了在水平两相流热交换器中插入扭曲带的影响，并给出了不同的蒸汽质量值（在0.1至0.7范围内）和质量速度值（在119至367 kgm ^-2范围内）s ^-1R600a（异丁烷）的强制对流冷凝期间应考虑）。测试用例是内径为8.1毫米，长度为1000毫米的铜制管道。此外，使用具有4、10和15的各种扭曲比（定义为扭曲带间距与试管内径之比）的三个扭曲带插入件。结果表明，与光滑情况相比，安装扭曲带会导致压降和传热速率的增加。此外，随着制冷剂质量速度和蒸气质量的增加，压降和传热速率增加。根据刀片的类型和操作条件，可以获得0.39至1.05之间的性能因子（与主要测试案例相比，评估性能改进的标准）。还观察到，存在最佳的制冷剂质量速度量，在该速度下性能因子较高。结果表明，除非在主要考虑提高传热率或可以合理地增加泵的功率消耗的情况下，否则在换热器中使用扭曲带通常无济于事。