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Steady-state HELP

  1. Aug 30, 2011 #1
    Steady-state HELP!!

    Hi guys, I really need some help with this!

    I have this set of equations for an evaporator which I want to calculate x0 and u0 for the steady state

    mdotin(hin - hg) + (B1/Ltot)*L1(Tw1 - Tr1) = 0
    mdotout(hg - hout) + (B2/Ltot)*L2(Tw2 - Tr2) = 0
    mdotin - mdotout = 0
    B3(Ta - Tw1) -B1(Tw1 - Tr1)
    B3(Ta - Tw2) -B2(Tw2 - Tr2)

    where B1,2,3 are constant values
    Ta is the surrounding air on the evaporator
    Ltot is the total length of the evaporator
    L2 = Ltot - L1
    hg the enthalpy of the vapor refrigerant

    My state variables are x = [L1 P hout Tw1 Tw2] and my control inputs are u = [mdotin mdotout hin] which results in the following set of equations

    u1(u3 - hg) + (B1/Ltot)*x1(x4 - Tr1) = 0
    u2(hg - x3) + (B2/Ltot)*(Ltot - x1)(x5 - Tr2) = 0
    u1 - u2 = 0
    B3(Ta - x4) - B1(x4 - Tr1) = 0
    B3(Ta - x5) - B2(x5 - Tr2) = 0

    I don't really know how to find the values of x0 and u0 from here.
    I would highly appreciate some help!

    Thanks in advance,
    Last edited: Aug 30, 2011
  2. jcsd
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