含不凝气(空气)的水蒸汽在波纹槽道内凝结换热实验研究

TWO PHASE-FLOW CONDENSATION WITH NONCONDENSABLE GASES IN A VERTICAL CORRUGATED DUCT

为了突破板式换热器的传统应用范围,1990年日本千代田公司与西德巴伐利亚合作,开发了称为“千代田-BAVEX”的全焊板式换热器,其传热系数为列管式换热器的2—3倍,压降为列管式的1/2—1,最高使用温度达720℃,最高工作压力达4.5MPa。这为板式换热器在炼油和石化中的应用开辟了广阔的前景。我国研制这种换热设备。

An experimental investigation of two phase-flow condensation with noncondensable gases in a vertical corrugated duct was conducted. The duct was constructed of two corrugated plates with corrugation inclination angles of β = 0° and β=45°, respectively (i.e., the angle between the corrugation and the bulk flow direction is indicated by β). The data was correlated as follows:For corrugated plate with β = 0°C0=0.0251Re0.246x-0.473200 ≤ Re ≤ 600 and 3.3%≤ x ≤ 24.6%For corrugated plate with β = 45°C0 = 0.031 3Re0 175x-0.525220 ≤ Re ≤ 740 and 3.3% ≤ x ≤ 24.6%The condensation with noncondensable gases heat transfer coefficient in the corrugated duct was much higher than that for bulk condensation with noncondensable gases on a vertical plate. A physical model was proposed to explain the heat transfer enhancement. Results of parametric studies involving the effect of air content, x, on the heat transfer coefficient were reported showing the significant difference from the case of bulk condensation with noncondensable gases on a vertical plate.