机械工程学报
機械工程學報
궤계공정학보
CHINESE JOURNAL OF MECHANICAL ENGINEERING
2010年
4期
99-104
,共6页
万忠民%刘伟%明廷臻%刘志春
萬忠民%劉偉%明廷臻%劉誌春
만충민%류위%명정진%류지춘
毛细抽吸两相流体回路%蒸发器%多孔介质%耦合计算
毛細抽吸兩相流體迴路%蒸髮器%多孔介質%耦閤計算
모세추흡량상류체회로%증발기%다공개질%우합계산
Capillary pumped loop%Evaporator%Porous media%Coupling computation
提出一种新型微小型平板毛细抽吸两相流体回路(Capillary pumped loop,CPL)的蒸发器结构,使其能够适应高热流密度散热的要求.分析蒸发器由于微型化后侧壁导热对系统传热能力的影响.建立新型蒸发器毛细多孔芯内的传热传质数学模型和液体补偿腔的流动与传热模型以及蒸汽槽道和金属外壁区域的导热模型,并用SIMPLE算法对蒸发器进行整场耦合求解.数值结果表明,工质蒸发发生在多孔芯上表面以及侧壁附近,采用热导率较大的铝外壁时,蒸发器加热表面的温度水平较低且温度均匀性较好,但侧壁导热的影响导致CPL的传热能力不高.外壁采用热导率较小的不锈钢可以明显提高CPL的传热极限能力,但同时却较大地增加了加热表面的温度水平以及不均匀性.采用组合结构的蒸发器一方面可以提高系统的传热能力,同时降低了加热表面的温度水平和温度梯度.
提齣一種新型微小型平闆毛細抽吸兩相流體迴路(Capillary pumped loop,CPL)的蒸髮器結構,使其能夠適應高熱流密度散熱的要求.分析蒸髮器由于微型化後側壁導熱對繫統傳熱能力的影響.建立新型蒸髮器毛細多孔芯內的傳熱傳質數學模型和液體補償腔的流動與傳熱模型以及蒸汽槽道和金屬外壁區域的導熱模型,併用SIMPLE算法對蒸髮器進行整場耦閤求解.數值結果錶明,工質蒸髮髮生在多孔芯上錶麵以及側壁附近,採用熱導率較大的鋁外壁時,蒸髮器加熱錶麵的溫度水平較低且溫度均勻性較好,但側壁導熱的影響導緻CPL的傳熱能力不高.外壁採用熱導率較小的不鏽鋼可以明顯提高CPL的傳熱極限能力,但同時卻較大地增加瞭加熱錶麵的溫度水平以及不均勻性.採用組閤結構的蒸髮器一方麵可以提高繫統的傳熱能力,同時降低瞭加熱錶麵的溫度水平和溫度梯度.
제출일충신형미소형평판모세추흡량상류체회로(Capillary pumped loop,CPL)적증발기결구,사기능구괄응고열류밀도산열적요구.분석증발기유우미형화후측벽도열대계통전열능력적영향.건립신형증발기모세다공심내적전열전질수학모형화액체보상강적류동여전열모형이급증기조도화금속외벽구역적도열모형,병용SIMPLE산법대증발기진행정장우합구해.수치결과표명,공질증발발생재다공심상표면이급측벽부근,채용열도솔교대적려외벽시,증발기가열표면적온도수평교저차온도균균성교호,단측벽도열적영향도치CPL적전열능력불고.외벽채용열도솔교소적불수강가이명현제고CPL적전열겁한능력,단동시각교대지증가료가열표면적온도수평이급불균균성.채용조합결구적증발기일방면가이제고계통적전열능력,동시강저료가열표면적온도수평화온도제도.
A novel evaporator of miniature flat plate capillary pumped loop (CPL) is presented for application of dissipating high heat flux. Based on the structure characteristics of miniature flat plate CPL evaporator, the effect of metal side wall conduction of evaporator on the CPL work limit is analyzed. An overall numerical model for the miniature flat plate CPL evaporator is presented, which includes heat and mass transfer in the porous wick structure, liquid flow and heat transfer in the compensation cavity and heat transfer in the vapor grooves and metallic wall. The entire evaporator is solved with SIMPLE algorithm as a conjugate problem. The numerical results show that liquid evaporation takes place near the upper and left surfaces of wick structure in the evaporator. The flat plate evaporator with single aluminum wall results in lower heat transfer limit, but leads to low temperature level and good isothermal behavior of the heated surface. On the other hand, the evaporator with single stainless steel wall leads to higher heat transport capacity, but to higher temperature level of the heated surface. The evaporator with combined wall (upper wall with aluminum, side and bottom wall with stainless steel) increases heat transfer limit, and decreases temperature level and temperature gradient on the heated surface, which implies that the CPL can operate safely and cooled apparatus also can work effectively under high heat fluxes.