中国机械工程
中國機械工程
중국궤계공정
CHINA MECHANICAl ENGINEERING
2014年
18期
2489-2495
,共7页
等温容器%对流换热系数%经验关系式%多孔介质%高压缩
等溫容器%對流換熱繫數%經驗關繫式%多孔介質%高壓縮
등온용기%대류환열계수%경험관계식%다공개질%고압축
isothermal chamber%convection heat transfer coefficient%empirical formula%porous media%high compression
为了提高等温容器的性能，对等温容器放气过程中的对流换热模型进行了研究。用4个已知流量特性的电磁阀分别对4种等温容器进行了放气实验，采集放气过程中的压力曲线，并采用“停止法”得到放气过程中的温度曲线。基于等温容器放气过程的热力学模型，结合放气过程中的压力曲线和温度曲线，确定了放气过程中的对流换热系数，最后利用相似原理拟合得到了放气过程中声速阶段和亚声速阶段的对流换热经验关系式。声速阶段和亚声速阶段的经验关系式不仅体现了放气速度对对流换热的影响，还反映了铜丝填充密度，也就是孔隙率对换热的影响；声速阶段的经验关系式中还引入了空气压缩比，体现了空气在高压缩状态下压缩性对对流换热的影响。
為瞭提高等溫容器的性能，對等溫容器放氣過程中的對流換熱模型進行瞭研究。用4箇已知流量特性的電磁閥分彆對4種等溫容器進行瞭放氣實驗，採集放氣過程中的壓力麯線，併採用“停止法”得到放氣過程中的溫度麯線。基于等溫容器放氣過程的熱力學模型，結閤放氣過程中的壓力麯線和溫度麯線，確定瞭放氣過程中的對流換熱繫數，最後利用相似原理擬閤得到瞭放氣過程中聲速階段和亞聲速階段的對流換熱經驗關繫式。聲速階段和亞聲速階段的經驗關繫式不僅體現瞭放氣速度對對流換熱的影響，還反映瞭銅絲填充密度，也就是孔隙率對換熱的影響；聲速階段的經驗關繫式中還引入瞭空氣壓縮比，體現瞭空氣在高壓縮狀態下壓縮性對對流換熱的影響。
위료제고등온용기적성능，대등온용기방기과정중적대류환열모형진행료연구。용4개이지류량특성적전자벌분별대4충등온용기진행료방기실험，채집방기과정중적압력곡선，병채용“정지법”득도방기과정중적온도곡선。기우등온용기방기과정적열역학모형，결합방기과정중적압력곡선화온도곡선，학정료방기과정중적대류환열계수，최후이용상사원리의합득도료방기과정중성속계단화아성속계단적대류환열경험관계식。성속계단화아성속계단적경험관계식불부체현료방기속도대대류환열적영향，환반영료동사전충밀도，야취시공극솔대환열적영향；성속계단적경험관계식중환인입료공기압축비，체현료공기재고압축상태하압축성대대류환열적영향。
In order to improve the performance of isothermal chamber ,a convection heat transfer model of isothermal chamber was studied during discharge .Four solenoid valves with known flow rate characteristics were used in four different isothermal chambers deflated experiments respectively ,pres-sure curve during discharge was collected ,and the temperature curve was collected by“stop method” . Based on the convection heat transfer model and combined with pressure curve and temperature curve during discharge ,the convection heat transfer coefficient was determined .Finally ,the convection heat transfer empirical formulae in sound velocity and subsonic speed phases were fitting by similarity prin-ciple respectively .The two empirical formulae include deflated speed and the copper wire filling densi-ty .That is to say the deflated speed and porosity can influence the heat transfer .The air compression ratio was introduced in the empirical formula of sound velocity phase .It can explain the problem that the heat transfer is influenced by compressibility w hile the air in the conditions of high compression .
