//EQUATIONS
//Units: SI, Temperatures in Celsius, pressures in bar
//Project file: D:\_classement\_Thopt\THERMOPTIM_Pro_282\proj\refrigIT_R134a.prj
//Date and Time: 2024-08-14 14:12:26

//Flow rate unit: kg/s

//GAS COMPOSITIONS

//PROCESSES

//Process: Compressor
//Equation: 1
m_dot_Compressor = m_dot_Evaporator // Upstream process - Evaporator
//Equation: 2
s_1 = s_Ph("R134a",p_1,h_1) // Upstream point - 1 - Downstream point - 2
// Comment = Isentropic reference
//Equation: 3
hs_2 = h_Ps("R134a",p_2,s_1) // Downstream point - 2
//Equation: 4
etaT_Compressor = 0.8// Isentropic efficiency
//Equation: 5
h_2 = h_1 + (hs_2 - h_1)/etaT_Compressor // Upstream point - 1 - Downstream point - 2
//Equation: 6
T_2 = T_Ph("R134a",p_2,h_2) // Downstream point - 2
// Comment = Given outlet pressure
//Equation: 7
p_2 = 14.0088// Outlet pressure
//Equation: 8
W_dot_Compressor = m_dot_Compressor*(h_2 - h_1) // DeltaH 

//Process: Desuperheating
//Equation: 9
m_dot_Desuperheating = m_dot_Compressor // Upstream process - Compressor
// Comment = isobaricExchange
//Equation: 10
p_3a = p_2 // Upstream point - 2 - Downstream point - 3a
// Comment = mDeltaH not set
//Equation: 11
Q_dot_Desuperheating/m_dot_Desuperheating = h_3a - h_2 // Upstream point - 2 - Downstream point - 3a - DeltaH/flow

//Process: Condensor
//Equation: 12
m_dot_Condensor = m_dot_Desuperheating // Upstream process - Desuperheating
// Comment = isobaricExchange
//Equation: 13
p_3 = p_3a // Upstream point - 3a - Downstream point - 3
// Comment = mDeltaH not set
//Equation: 14
Q_dot_Condensor/m_dot_Condensor = h_3 - h_3a // Upstream point - 3a - Downstream point - 3 - DeltaH/flow

//Process: Evaporator
// Comment = isobaricExchange
//Equation: 15
p_1 = p_4 // Upstream point - 4 - Downstream point - 1
// Comment = mDeltaH not set
//Equation: 16
Q_dot_Evaporator/m_dot_Evaporator = h_1 - h_4 // Upstream point - 4 - Downstream point - 1 - DeltaH/flow

//Process: Expansion valve
//Equation: 17
m_dot_Expansionvalve = m_dot_Condensor // Upstream process - Condensor
// Comment = Isenthalpic throttling
//Equation: 18
p_4 = 4.49// Given outlet pressure
//Equation: 19
xl_4 = 0.// Saturated liquid quality
//Equation: 20
Tl_4 = T_4- 0.01// Saturated liquid temperature
//Equation: 21
xv_4 = 1.// Saturated vapor quality
//Equation: 22
Tv_4 = T_4+ 0.01// Saturated vapor temperature
//Equation: 23
hl_4 = hsat_Px("R134a",p_4,xl_4)// Saturated liquid enthalpy
//Equation: 24
hv_4 = hsat_Px("R134a",p_4,xv_4)// Saturated vapor enthalpy
//Equation: 25
x_4 = (h_3 - hl_4)/(hv_4 - hl_4)// Quality
//Equation: 26
T_4 = Tsat_P("R134a",p_4) // Downstream point - 4
//Equation: 27
h_4 = hsat_Px("R134a",p_4,x_4) // Enthalpy

//NODES

//HEAT EXCHANGERS

//Number of equations: 27

//POINTS WITH SATURATION TEMPERATURE SET


//Point 3

//Outlet point of process Condensor
//Equation: 28
x_3 = 0.0// Quality
//Equation: 29
dTsat_3 = 0.0// Deviation from Tsat
//Equation: 30
T_3 = Tsat_P("R134a",p_3)+dTsat_3// set Tsat (Celsius)
//Equation: 31
h_3 = hsat_Px("R134a",p_3,x_3)// Enthalpy


//Point 3a

//Outlet point of process Desuperheating
//Equation: 32
x_3a = 1.0// Quality
//Equation: 33
dTsat_3a = 0.0// Deviation from Tsat
//Equation: 34
T_3a = Tsat_P("R134a",p_3a)+dTsat_3a// set Tsat (Celsius)
//Equation: 35
h_3a = hsat_Px("R134a",p_3a,x_3a)// Enthalpy


//Point 4
//Equation: 36
//p_4 = 4.49// P (bar)
//Equation: 37
//x_4 = 0.309543457// Quality
//Equation: 38
dTsat_4 = 0.0// Deviation from Tsat
//Equation: 39
T_4 = Tsat_P("R134a",p_4)+dTsat_4// set Tsat (Celsius)
//Equation: 40
//h_4 = hsat_Px("R134a",p_4,x_4)// Enthalpy


//Point 1

//Outlet point of process Evaporator
//Equation: 41
x_1 = 1.0// Quality
//Equation: 42
dTsat_1 = 0.0// Deviation from Tsat
//Equation: 43
T_1 = Tsat_P("R134a",p_1)+dTsat_1// set Tsat (Celsius)
//Equation: 44
h_1 = hsat_Px("R134a",p_1,x_1)// Enthalpy


//OTHER POINTS WITH PRESSURE SET


//SET FLOW RATES

//Equation: 45
m_dot_Evaporator = 0.0088// Given flow 

//OVERALL BALANCE

//Equation: 46
usefulEnergy = Q_dot_Evaporator
//Equation: 47
purchasedEnergy = W_dot_Compressor
//Equation: 48
eta0 = usefulEnergy/purchasedEnergy
//Equation: 49
eta = abs(eta0)