第八章 热量衡算
8.1 塔顶热量衡算
表8-1苯—甲苯的蒸发潜热与临界温度
物质 苯 甲苯
由： QC?(R?1)?D?(IVD?ILD)
其中 IVD?ILD?XD??HVA?(1?XD)??HVB
1?Tr20.38) ?HV2??HV1?(1?Tr1沸点0C 80.1 110.63
蒸发潜热KJ/Kg
394 363
临界温度TC/K
288.5 318.57
则: t D = 81.7 0C时 苯:
Tr2?(81.7?273.15)/288.5?1.23Tr1?(80.1?273.15)/288.5?1.22
1?Tr20.381?1.230.38)?394?()?400.71kJ/kg 蒸发潜热 ?HV2??HV1?(1?Tr11?1.22甲苯: Tr 2 = (81.7 + 273.15) / 318.57 = 1.11
Tr1 = (110.63 + 273.15) / 318.57 = 1.2
1?Tr20.381?1.110.38)?363?()?289.23kJ/kg 蒸发潜热 ?HV2??HV1?(1?Tr11?1.2 M D = 78.59g / mol
D ' = M D × D = 78.587 × 15.31=1203.21kJ / kg
IVD –I LD = X D ×△HVA -(1 -X D ) ×△HVB
= 0.966 × 400.71- (1- 0.966) × 289.23
= 377.25kJ / kg
QC = ( R + 1) × D ' × ( IVD- I LD )
= (2.46+1) × 1203.21 × 377.25 =1.571×106 kJ / kg
8.2塔底热量衡算
QC?(R?1)?D?(IVD?ILD)
其中 IVD?ILD?XD??HVA?(1?XD)??HVB
1?Tr20.38 ?HV2??HV1?()
1?Tr1则: tw=107.80C
苯: Tr 2 = (107.8 + 273.15) / 288.5 = 1.32
Tr1 = (80.1 + 273.15) / 288.5 = 1.22
蒸发潜热 △HV 1 = △HV 1 ×[( 1- Tr 2) /(1-Tr1)]0.38
= 394 ×[( 1-1.32) /(1-1.22)]0.38=454.29 kJ / kg
甲苯: Tr 2 = (107.8 + 273.15) / 318.57 = 1.196
Tr1 = (110.63 + 273.15) / 318.57 = 1.2047
蒸发潜热 △HV 2 = △HV 1 ×[( 1- Tr 2) /(1-Tr1)]0.38
= 363×[( 1-1. 1995) /(1-1.2047)]0.38=357.058
MW = 91.47kg / mol
D ' = MW × W = 91.47× 16.362= 1496.362J / kg IVw- I Lw = (1- X w) ×△HV2- X w×△HV1
= (1- 0.0468) × 359.47 -0.00.468× 454.29 = 319.09kJ / kg
QC = ( R + 1) × D ' × ( IVD- I LD