作者Jerryamd (Let's go cubbies)
看板Physics
标题[题目] 热力学的问题
时间Thu Nov 25 00:03:45 2010
[领域] (题目相关领域)
热力学
[来源] (课本习题、考古题、参考书...)
课本习题
[题目]
Water flows steadily through a feedwater heater, being heated by two sources:
one source adds 1000 kW from a 100 deg-C reservoir and the other source adds
heat from a 200 deg-C reservoir. Water enters with a mass flow rate of 5 kg/s
at 5 MPa, 20 deg-C and leaves at 5 MPa and 180 deg-C. (a) Determine the rate
of entropy generation in the system's universe in kW/K. (b) the exergetic
efficiency in percent. Use the SL model for water.
[瓶颈] (写写自己的想法，方便大家为你解答)
想请问一下版上的前辈一题热力学的习题.
想请问一下.在这种有两个热源的情况下.
应该要怎麽处理..?
应该要把它当成两个不同的 single flow 再做平均嘛 ??
假设没有输出功...(题目没写就当作他没有罗..XD)
我有试着直接代入 entropy equation ,可是一直得到负值.
应该是不可能的吧..@@~
感谢回答的前辈..谢谢
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