A.密度较大
B.放热系数较低
C.密度较小
D.比热容较小
第8题
16.8MPa锅炉的再热蒸汽特性参数
t (℃) | u×10-6 [kg/(m·s)] | cp [kJ/(kg·K)] | λ×10-3 [W/(m·K)] | t (℃) | u×10-6 [kg/(m·s)] | cp [kJ/(kg·K)] | λ×10-3 [W/(m·K)] |
280 | 18.96 | 3.015 | 50.23 | 420 | 25.24 | 2.325 | 60.73 |
300 | 19.89 | 2.777 | 50.85 | 440 | 26.10 | 2.307 | 62.88 |
320 | 20.81 | 2.622 | 51.92 | 460 | 26.96 | 2.295 | 65.12 |
340 | 21.72 | 2.516 | 53.30 | 480 | 27.81 | 2.287 | 67.42 |
360 | 22.61 | 2.442 | 54.93 | 500 | 28.65 | 2.283 | 69.79 |
380 | 23.50 | 2.389 | 56.73 | 520 | 29.48 | 2.282 | 72.21 |
400 | 24.37 | 2.352 | 62.88 | 540 | 30.31 | 2.283 | 74.68 |
第9题
13.7MPa锅炉的再热蒸汽特性参数
t (℃) | u×10-6 [kg/(m·s)] | cp [kJ/(kg·K)] | λ×10-3 [W/(m·K)] | t (℃) | u×10-6 [kg/(m·s)] | cp [kJ/(kg·K)] | λ×10-3 [W/(m·K)] |
270 | 18.62 | 2.727 | 46.97 | 420 | 25.24 | 2.254 | 59.70 |
280 | 19.08 | 2.639 | 47.41 | 440 | 26.10 | 2.246 | 61.93 |
300 | 19.99 | 2.509 | 48.57 | 460 | 26.94 | 2.241 | 64.23 |
320 | 20.88 | 2.420 | 50.02 | 480 | 27.79 | 2.240 | 66.58 |
340 | 21.77 | 2.359 | 51.68 | 500 | 28.62 | 2.242 | 68.99 |
360 | 22.65 | 2.316 | 53.51 | 520 | 29.45 | 2.245 | 71.45 |
380 | 23.52 | 2.287 | 55.47 | 540 | 30.28 | 2.249 | 73.94 |
400 | 24.38 | 2.267 | 61.93 |
第10题
已知,亚临界压力锅炉的主蒸汽压力p1=16.8MPa,主蒸汽温度t1=540℃,再热蒸汽压力p2=3.86MPa,再热蒸汽温度t2=540℃,再热蒸汽入口温度t0=280℃,给水温度tgs=270℃,已知条件列于下表。计算该压力下水蒸气热力循环过程中主蒸汽加热过程的Pr并对计算结果进行分析与讨论。
16.8MPa锅炉的主蒸汽特性参数
t (℃) | u×10-6 [kg/(m·s)] | cp [kJ/(kg·K)] | λ×10-3 [W/(m·K)] | t (℃) | u×10-6 [kg/(m·s)] | cp [kJ/(kg·K)] | λ×10-3 [W/(m·K)] |
360 | 23.92 | 9.948 | 113.22 | 460 | 27.76 | 3.375 | 82.9'2 |
370 | 24.13 | 7.396 | 101.17 | 470 | 28.19 | 3.267 | 83.11 |
380 | 24.45 | 6.099 | 94.51 | 480 | 28.62 | 3.174 | 83.44 |
390 | 24.82 | 5.307 | 90.34 | 490 | 29.04 | 3.095 | 83.91 |
400 | 25.22 | 4.770 | 87.57 | 500 | 29.47 | 3.026 | 84.48 |
410 | 25.63 | 4.380 | 85.69 | 510 | 29.89 | 2.967 | 85.15 |
420 | 26.05 | 4.083 | 84.43 | 520 | 30.31 | 2.915 | 85.90 |
430 | 26.48 | 0.000 | 82.91 | 530 | 30.73 | 2.870 | 86.72 |
440 | 26.90 | 3.660 | 83.13 | 540 | 31.15 | 2.830 | 87.60 |
450 | 27.33 | 3.504 | 82.91 |
为了保护您的账号安全,请在“上学吧”公众号进行验证,点击“官网服务”-“账号验证”后输入验证码“”完成验证,验证成功后方可继续查看答案!