課程名稱︰熱力學
課程性質︰必修
課程教師︰黃美嬌
開課學院：工學院
開課系所︰機械系
考試日期（年月日）︰2007/11/10
考試時限（分鐘）：180
是否需發放獎勵金：是
（如未明確表示，則不予發放）
試題 :
1.(10%)Describe the characteristics of the following terminologies:
(a)a closed system
(b)an isolated system
(c)a simple compressible system
(d)a quasi-equilibrium process
(e)the gage pressure
2.(20%)A gasoline line is connected to a pressure gage through a double-U
manometer as shown below. If the reading of the pressure gage is 200Kpa,
determine the gage pressure of the gasoline line.
(圖有點難畫，反正就是高中學的U形管氣壓計的加深題)
3.(20%)Consider a well-insulated tank that is divided into two compartments by
a piston that is free to move but does not allow either gas to leak into the
other side. Initially, one side of the piston contains 0.8m^3 of N2 gas at
500kpa and 95度C while the other side contains 1.3m^3 of He gas at 500kpa
and 25度C. The piston is made of 6.4kg of iron initially at 60度C. Determine
the final equilibrium temperature and pressure when a thremal equilibrium is
established as a result of heat transfer through the piston.
4.(25%)Steam at 48度C condenses on the outside of a 6-m-long, 4-cm-diameter
thin horizontal copper tube by cooling water that enter the tube at 24度C
and 5Mpa at an average velocity of 2.2m/s and leaves at 37度C and 5Mpa.
Determin the rat of condensation of steam by
(a)using the compressed liquid tables.
(b)by approximating the water as asaturated liquid.
(c)by using the pressure correction.
5.(25%)An air compressor is to be powered by a direct-coupled steam turbine
that is also driving a generator. Steam enters the turbine at 13Mpa and
550度C at a rate of 22kg/s and exits at 12kpa and a quality of 0.88. Air
enters the compressor at 102Kpa and 296K at a rate of 12kg/s and exits at
1Mpa and 630K. The efficiencies of the air compressor and the steam turbine
are 0.9 and 0.82, respectively. Determine
(a)the net power delivered to the generator by the turbine and
(b)the total heat loss of the compressor and the turbine.
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