南京理工大学学报（自然科学版）
南京理工大學學報（自然科學版）
남경리공대학학보（자연과학판）
JOURNAL OF NANJING UNIVERSITY OF SCIENCE AND TECHNOLOGY
2014年
3期
419-423
,共5页
R134a%锯齿型翅片%沸腾换热%质量流速%Bertsch 关联式%板翅式蒸发器%表面温度%对流换热系数%平直通道%制冷量
R134a%鋸齒型翅片%沸騰換熱%質量流速%Bertsch 關聯式%闆翅式蒸髮器%錶麵溫度%對流換熱繫數%平直通道%製冷量
R134a%거치형시편%비등환열%질량류속%Bertsch 관련식%판시식증발기%표면온도%대류환열계수%평직통도%제랭량
R134a%offset strip fins%boiling heat transfer%mass flow rates%Bertsch correlation%plate-fin evaporators%surface temperature%convective heat transfer coefficients%straight channels%cooling capacities
为设计板翅式蒸发器,采用实验方法研究不同质量流速下 R134a 在锯齿型翅片中的沸腾换热系数。对比 Bertsch 关联式计算值与实验值得到其沸腾换热系数修正式,并通过相同型面板翅式蒸发器实验对该修正式进行验证。实验结果表明：在不同入口条件下,沿流动方向,锯齿型翅片表面温度变化趋势一致,由起初较平稳状态到距入口290 mm 处显著增大；在相同质量流速下,R134a 在锯齿型翅片中的对流换热系数远大于平直通道；Bertsch 关联式沸腾换热系数修正式计算的制冷量与实验值误差约为10%。
為設計闆翅式蒸髮器,採用實驗方法研究不同質量流速下 R134a 在鋸齒型翅片中的沸騰換熱繫數。對比 Bertsch 關聯式計算值與實驗值得到其沸騰換熱繫數脩正式,併通過相同型麵闆翅式蒸髮器實驗對該脩正式進行驗證。實驗結果錶明：在不同入口條件下,沿流動方嚮,鋸齒型翅片錶麵溫度變化趨勢一緻,由起初較平穩狀態到距入口290 mm 處顯著增大；在相同質量流速下,R134a 在鋸齒型翅片中的對流換熱繫數遠大于平直通道；Bertsch 關聯式沸騰換熱繫數脩正式計算的製冷量與實驗值誤差約為10%。
위설계판시식증발기,채용실험방법연구불동질량류속하 R134a 재거치형시편중적비등환열계수。대비 Bertsch 관련식계산치여실험치득도기비등환열계수수정식,병통과상동형면판시식증발기실험대해수정식진행험증。실험결과표명：재불동입구조건하,연류동방향,거치형시편표면온도변화추세일치,유기초교평은상태도거입구290 mm 처현저증대；재상동질량류속하,R134a 재거치형시편중적대류환열계수원대우평직통도；Bertsch 관련식비등환열계수수정식계산적제랭량여실험치오차약위10%。
In order to design plate-fin evaporators,the boiling heat transfer coefficients of R134a in offset strip fins are studied experimentally under different mass flow rates. A modified formula of the boiling heat transfer coefficient of Bertsch correlation is obtained by comparing the calculation data of Berstch correlation with the experimental data, and it is verified by experiments of a plate-fin evaporator with the same structure. The experimental results show that the surface temperature of offset strip fins along the flow direction has the same changing trend under different entrance conditions,which almost has no change in the beginning but increase significantly at 290 mm position;under the same mass flow rates,the convective heat transfer coefficients of R134a in offset strip channels are much larger than those in straight channels;the deviations of cooling capacities calculated by the boiling heat transfer coefficient modified formula of Berstch correlation from experimental results are about 10% .
