A、<span style="font-size: 10.5pt; font-family: 宋体;">管内对流传热系数减小</span>
B、<span style="font-size: 10.5pt; font-family: 宋体;">对数平均温差减小</span>
C、<span style="font-size: 10.5pt; font-family: 宋体;">管内阻力减小</span>
D、<span style="font-size: 10.5pt; font-family: 宋体;">总对流传热系数减小</span>