螺旋扭片换热器壳程传热与流阻研究

STUDY ON THE SHELL SIDE HEAT TRANSFER AND FLOW RESISTANCE OF HELICAL RIBBON HEAT EXCHANGER

在水-水系统下对新型螺旋扭片换热器与普通弓型折流板换热器进行壳程传热与流阻对比试验,考察了扭片开孔与否对螺旋扭片换热器壳程传热性能的影响规律。结果表明,在相同流量下,螺旋扭片换热器单位压降下的壳程传热膜系数为普通弓型折流板换热器的1.4～8.0倍;而开孔扭片换热器的传热效果优于无孔扭片换热器。说明螺旋扭片换热器是一种结构更为合理的新型换热设备,有较好的传热与流阻特性,应用前景广阔。

A new type of shell tube heat exchanger having longitudinal-helical flows was studied, in which heat transfer on the shell side of the exchanger was enhanced by inserting helical ribbons between tubes. Using hot water in shell side and cool water in tube side, experiments were carried out to compare the heat transfer performance and flow resistance in the shell side between the new type of heat exchanger and the conventional bow-type baffle heat exchanger. Besides, the effect of ribbons with and without holes on the heat transfer performance was investigated as well. Results showed that under the same pressure drop, the heat transfer coefficient in shell side for helical ribbon heat exchanger was 1.4-8.0 times of that for baffle heat exchanger ; the heat transfer performance of heat exchanger having ribbons with holes was better than that of heat exchanger having ribbons without hole. This type of new helical ribbon heat exchanger had good performance of heat transfer and flow resistance due to its improved structure, thus it might have a promising application prospect.