【摘要】 进行了不同真空度下单管的凝结试验,研究了真空状态下等离子注入铜管管束的换热特性,以及其换热系数随Re数的变化情况,并与普通铜管管束的换热性能进行比较。研究表明:两种管束的凝结换热系数和总换热系数都随着真空度的提高而增大,而且真空状态下等离子注入铜管表面较普通铜管有更好的换热性能。在较高真空度(0.05 MPa)和较大Re数(34755)下,等离子管束的总换热系数约为普通铜管管束的1.43倍,凝结换热系数约为普通铜管管束的2倍。图6表1参11更多还原

【Abstract】 Different from condensation tests,performed with single tubes under atmospheric pressure,condensation tests of brass tube bundles with implanted ions were carried out under various vacuum conditions for the purpose of studying their their heat-transfer properties.Their heat-transfer coefficients for varying Re numbers are shown,accompanied by a comparison with heat-transfer properties of common brass tube bundles.Test results show that the condensation heat-transfer coefficient,as well as the overall coefficient of common and of ion implanted brass tube bundles,both increase with rising vacuum,and that the latter ones have better heat-transfer properties under vacuum conditions.Under higher vacuum(0.05 MPa) condition,for larger Re number(34755),the overall coefficients of ion implanted tube tube bundles are about 1.43 times those of the common ones,and the condensation heat-transfer coefficient around 2 times.Figs 6,table 1 and refs 11.更多还原