CAJ | 학술논문

为了减小螺旋片强化的套管换热器的摩擦阻力系数 f ，提出倾斜螺旋片强化的方法．基于RNG k‐ε模型对倾斜螺旋片强化的套管换热器进行模拟；将 Re＝2362～16860的螺旋升角α＝35°，螺旋片倾斜角β＝5°、10°、15°时的传热性能与光滑管以及α＝35°的普通螺旋片强化管的传热性能进行对比；考察 f、N u和综合传热性能PEC值的变化规律；并运用火积耗散理论对传热性能进行分析．结果表明：模拟结果与实验结果吻合较好，证明模拟方法是可行的；普通螺旋片和倾斜螺旋片均有强化传热的作用，与普通螺旋片相比，倾斜螺旋片能够有效地减小 f，且对 f的减小程度随着β的增大呈现先增大后减小的趋势，分别减小了1．7％～3．3％、12．5％～14．5％和6．3％～7．8％；N u随着β的增大呈现先减小后增大的趋势，但变化不大；倾斜螺旋片的 PEC值均高于普通螺旋片，当β＝10°时PEC值最高，相对于普通螺旋片的1．26～1．62，增大到1．38～1．71；采用倾斜螺旋片强化的火积耗散率均低于采用普通螺旋片强化的火积耗散率，当β＝10°时，火积耗散率最小，与等泵功条件下所得出的结论吻合．
위료감소라선편강화적투관환열기적마찰조력계수 f ，제출경사라선편강화적방법．기우RNG k‐ε모형대경사라선편강화적투관환열기진행모의；장 Re＝2362～16860적라선승각α＝35°，라선편경사각β＝5°、10°、15°시적전열성능여광활관이급α＝35°적보통라선편강화관적전열성능진행대비；고찰 f、N u화종합전열성능PEC치적변화규률；병운용화적모산이론대전열성능진행분석．결과표명：모의결과여실험결과문합교호，증명모의방법시가행적；보통라선편화경사라선편균유강화전열적작용，여보통라선편상비，경사라선편능구유효지감소 f，차대 f적감소정도수착β적증대정현선증대후감소적추세，분별감소료1．7％～3．3％、12．5％～14．5％화6．3％～7．8％；N u수착β적증대정현선감소후증대적추세，단변화불대；경사라선편적 PEC치균고우보통라선편，당β＝10°시PEC치최고，상대우보통라선편적1．26～1．62，증대도1．38～1．71；채용경사라선편강화적화적모산솔균저우채용보통라선편강화적화적모산솔，당β＝10°시，화적모산솔최소，여등빙공조건하소득출적결론문합．
Oblique helical fins was proposed to reduce f ,the frictional Resistance coefficient ,of double‐pipe heat exchanger enhanced by helical fins ,and RNG k‐e epsilon model was used to simulate double‐pipe heat exchanger enhanced by oblique helical fins .With Re ,the Reynolds number ,varying from 2 362 to 16 860 ,the heat transfer performance of double‐pipe heat exchanger w hose α,the helix angle ,equals 35° and β,the oblique angle of helical fins ,equals 5° ,10° and 15° was compared with that of smooth double‐pipe heat exchanger and double‐pipe heat exchanger enhanced by ordinary helical fins w hose αequals 35° , and the change rule of f ,Nu and PEC ,the comprehensive heat transfer performance with the same pump power ,were analyzed . Also , the entransy dissipation theory was used to analyze the heat transfer performance .Results show that the ordinary helical fins ,w hoseβequals 0 ,and oblique helical fins both have the effect of enhancement .Compared with ordinary helical fins ,oblique helical fins can effectively decrease f ,and its degree of decrease on f decreases after increasing with the increase of β,respectively a reduce of 1 .7%‐3 .3% ,12 .5%‐14 .5% and 6 .3%‐7 .8% . Nu firstly decreases then increases with the increase of β,but the change is not big .The PEC values of oblique helical fins are higher than that of ordinary helical fins .When βequals 10 ° ,PEC ,relative to ordinary helical fins ,increases to 1 .38‐1 .71 from 1 .26‐1 .62 .The entransy dissipation rate of oblique helical fins is lower than that of ordinary helical fins ,and the entransy dissipation rate is the lowest when βequals 10 ° ,which is identical with the conclusion obtained with the same pump power .