Sunday, February 6, 2011

Final thermodynamics


NO.
QUESTIONS

1
  • Properties table

Compress liquid and superheated x is (-)
           Saturated liquid x =0
      [No pressure in table compress liquid water A7] and [For refrigerant-134a no compress table] so take saturated liquid for example Vf


T                     V
300’           2.6389
 360’           ?
400’            3.1027
 Solution:
360-300 =     ?    -   2.6389
400-300              3.1027-2.6389

havg=hf + x hfg

T<TSAT  compress liquid

u>u
g superheated vapor

       





        
     
        
   

        






2
  • Theory

The first of thermodynamics is essentially an expression of the conservation of energy principle(prinsip pemuliharaan tenaga).
Energy cannot be created or destroy. Energy can only transform from one form to another.

Apllication- 
·         Cyclic process
·         Isobaric
·         Isothermal


  • Calculate Q, boundary work(closed system)
W= P
Q-W=∆U
Q=∆U+W
(U2-U1)+P(V2-V1)
m(u2-u1) + Pm(v2-v1)
m( u2+P v2)-( u1+P v1)
m(h2)-m(h1)
m(h2-h1)




    


















    3
    • Theory(maybe open closed system)
    Open system is matter may flow in and out of the system boundaries
    Closed system is energy can cross the boundaries the form of heat or work
         

    • Calculation nozzle & turbin
    LOOK EXAMPLE( ALREADY DISCUSS)




                       
    4
    • Theory carnot,clausis/Kelvin

    Kelvin-it is impossible for any device that operates on  a cycle, to receive heat from a single reservoir and produce a net amout of work 
    ( Kelvin-tidak mungkin untuk setiap peranti yang beroperasi pada kitaran, untuk menerima panas dari reservoir tunggal dan menghasilkan amout bersih kerja)

    Clausius-it is impossible to construct a device that operates in a cycle and produces no effect other than the transfer of heat from a lower temperature body to a higher temperature body
    ( Clausius-tidak mungkin untuk membina sebuah peranti yang beroperasi dalam kitaran dan tidak menghasilkan kesan lain selain transfer panas dari suhu tubuh lebih rendah ke suhu badan lebih tinggi)


    • Calculation(toturial 4)
    {heat engine & heat pump}

    LOOK NOTE LEC.GIVE










    5
    • Theory carnot

    Theory carnot—carnot was the first to introduce the concept of cyclic operation and devised a reversible cycle that is composed of four reversible processes, two isothermal and two adiabatic.


    • Calculation,Sgen
    LOOK NOTE LEC.GIVE


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