9 h-hs 吸热量 2992.4-154.82=2837.58kJ/kg 放热量 92=h2a-h = 2012.43-151.47=1860.96kJ/kg 循环净功 Wnet=q1-q2≈W =2837.58-1861.96=975.62kJ1kg 汽耗率 d 3600 3600 3.69kg/kW.h Wnet 975.62 热效率 W吨 975.62 34.38% 91 2837.58
吸热量 kJ kg q h h 2992.4 154.82 2837.58 / 1 1 4 = − = = − 放热量 kJ kg q h a h 2012.43 151.47 1860.96 / 2 2 3 = − = = − 循环净功 kJ kg wnet q q wt 2837.58 1861.96 975.62 / 1 2 = − = = − ≈ 汽耗率 kg kW h w d net 3.69 / . 975.62 3600 3600 = = = 热效率 34.38% 2837.58 975.62 1 = = = q wnet η
举例1b(P235) p1=3MPa,ta=300°C,p2=0.006MPa,tb=500°C 求：91=？92=？；w=?wn=? wne=?X2=?;7=?;d=? 解：查表 p1=3MPa;t6=500°C h6=3454.9kJ1kg b S1b =7.2314kJ/kg.K 2a
举例1b（P235） p MPa t a C p MPa t b C 3 , 300 , 0.006 , 500 1 = 1 = 2 = 1 = ? ?; ?; ? ?; ?; ?; ?; 2 1 2 = = = = = = = = w x d q q w w net T p η 求： p MPa t b C 1 = 3 ; 1 = 500 解：查表 s kJ kg K h kJ kg b b 7.2314 / . 3454.9 / 1 1 = = 1 4 3 2a T s 2b 1b 1a
s26=S16=7.2314kJ/kg.K p2=0.006MPa =0.5208kJ/g.K;s"=8.3283kJ/kg.K s26-S7.2314-0.5208 X2b =0.8595 s"-s' 8.3283-0.5208 h'=151.47kJ/kg h"=2566.48kJ/kg h2b=x26h"+(1-x26)h =2566.48×0.8595+(1-0.8595)×151.47 2227.17kJ/kg
s ′ = 0.5208kJ / kg.K;s ′′ = 8.3283kJ / kg.K p MPa s b s b kJ kg K 0.006 7.2314 / . 2 2 1 = = = 0.8595 8.3283 0.5208 2 7.2314 0.5208 2 = − − = ′′ − ′ − ′ = s s s s x b b h kJ kg h kJ kg 2566.48 / 151.47 / ′′ = ′ = kJ kg h b x bh x b h 2227.17 / 2566.48 0.8595 (1 0.8595) 151.47 (1 ) 2 2 2 = = × + − × = ′′ + − ′ 2b 4 3 2a T s 2b 1b 1a
s3=s'=0.5208kJ/kg.K h,=h'=151.47kJ/kg S4=S3=0.5208kJ/kg.K P=3MPa h4=154.82kJ1kg 汽轮机作功 w,=h-h 3454.9-2227.17=1227.73kJ/kg 水泵作功 wp =hs -hs =154.28-151.47=3.35kJ/kg
3 h h kJ kg s s kJ kg K 151.47 / 0.5208 / . 3 3 = ′ = = ′ = 4 p MPa s s kJ kg K 3 0.5208 / . 4 4 3 = = = h4 =154.82kJ / kg 汽轮机作功 kJ kg wt h h 3454.9 2227.17 1227.73 / 1 2 = − = = − 水泵作功 kJ kg wp h h 154.28 151.47 3.35 / 4 3 = − = = −
9 h-ha 吸热量 =3454.9-154.82=3300.08kJ1kg 放热量 92=h26-h3 = 2227.17-151.47=2075.17kJ/kg 循环净功 Wnet =91-92 =Wi =3300.08-2075.17=1224.91kJ/kg 3600 3600 汽耗率 = 2.939kg/kW.h Wnet 1224.91 1224.9 热效率 net = 37.12% 91 3300.08
吸热量 kJ kg q h h 3454.9 154.82 3300.08 / 1 1 4 = − = = − 放热量 kJ kg q h b h 2227.17 151.47 2075.17 / 2 2 3 = − = = − 循环净功 kJ kg wnet q q wt 3300.08 2075.17 1224.91 / 1 2 = − = = − = 汽耗率 kg kW h w d net 2.939 / . 1224.91 3600 3600 = = = 热效率 37.12% 3300.08 1224.9 1 = = = q wnet η