复式波纹板型一次表面回热器传热及阻力特性的研究

Performance of Heat Transfer and Drag Characteristics for Recuperator with Corrugated-Undulated Primary Surfaces

采用单吹瞬变法对自行设计的3种CU型一次表面回热器的传热与阻力特性进行了试验研究．建立了数学模型，由数值解求得流体的出口温度与时间及传热单元数NTU间的函数关系．通过配比，获得了换热表面在测定工况下的NTU值．在紧凑式回热器常用的Re=200～800范围内，获得3种CU表面的j因子和f因子的试验关联式．换热面当量直径仅为1．35～1．48mm，属微小尺度，交错角为52．5°～67．5°．采用综合评价因子j／f对3种表面的性能进行了分析，结果表明1号试件表面具有较佳的性能．经误差分析，所提供的实验关联式的拟合误差不大于16％，具有足够的工程精度．

Based on the single blow transient technique, experimental research on the performance of heat transfer and drag characteristics for self-designed three types of test piece with corrugated-undulated （CU） primary surfaces was conducted. A mathematical model was established, and the functional relations be- tween outlet temperature and time and number of heat transfer units （NTU） were obtained by numerical solution. The value of NTU under testing condition was obtained by a matching method. Within the normal range of Re= 200-1200 for the compact recuperator, the correlations of heat transfer factor j and friction factor f for three types of CU surface were obtained. The equivalent diameter of heat transfer surface is only from 1.35 to 1.48 mm, belonging to mini scale, and with alternate angle of 52.5°-67.5°. Performance analysis was made for three types of heat transfer surfaces based on the comprehensive evaluating index j/f. Results show that number one test piece has good comprehensive performance. By error analyzing, the regressive errors of correlations were less than 16% with sufficient engineering accuracy.