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实验研究了超临界RP-3管内换热特性。实验段为2100mm长、外径2.2mm,内径1.8mm不锈钢管(材质:1Cr18Ni9Ti)。RP-3在5MPa压力下流经该实验管,采用近似等热流加热方式将其从127℃加热至427℃。通过测量0min,20min,30min,45min和60min时管外壁和流体温度得到管内对流换热系数hin沿流向分布、结焦对管内传热系数Kin影响。研究结果表明:在远离临界点的亚临界区域,hin随着RP-3温度上升逐渐增大;在近临界区管内对流换热系数迅速增加;而进入超临界区域后,hin保持在1.8×104W/(m·℃)附近;结焦对管内传热影响显著,Kin随结焦增多逐渐降低,而降幅逐渐减小。
Experimental study of the supercritical RP-3 tube heat transfer characteristics. Experimental section is 2100mm long, outer diameter 2.2mm, inner diameter 1.8mm stainless steel tube (material: 1Cr18Ni9Ti). RP-3 was passed through the test tube at a pressure of 5 MPa and heated from 127 ° C to 427 ° C using an approximately isothermal heat flow. By measuring the outer wall and the fluid temperature at 0min, 20min, 30min, 45min and 60min, the influence of the convective heat transfer coefficient hin along the flow direction and the heat transfer coefficient Kin of the coke on the tube was obtained. The results show that in the subcritical region away from the critical point, hin increases with the increase of RP-3 temperature, and the convective heat transfer coefficient increases rapidly in the near-critical region. When entering the supercritical region, the hin remains at 1.8 × 104W / (m · ℃); coking has a significant effect on the heat transfer inside the tube, Kin decreases gradually with the increase of coking, and decreases gradually.