标准大气压下,沸点-195.8℃时,液态氮的汽化热是2.7928千焦/摩尔.
液氮密度810千克每立方米
液氮分子量28
所以一立方液氮气化吸收热量=(1*810/28)*2.7928=80.79千焦.
汽化热依赖于温度和压力,以下列几个数据作为例子:
Temperature (C) → Pressure (atm) → Vaporization Heat (kJ/kg)
-55 → 5.4672 → 347.899
-50 → 6.7342 → 339.737
-45 → 8.2096 → 331.26
-40 → 9.9136 → 322.42
-35 → 11.867 → 313.18
-30 → 14.091 → 303.48
-25 → 16.607 → 293.27
-20 → 19.439 → 282.44
-15 → 22.608 → 270.93
-10 → 26.14 → 258.62
-5 → 30.06 → 245.33
0 → 34.396 → 230.89