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HeatExchanger2_CL

 

 

The procedure HeatExchanger2_CL models a heat exchanger in which two fluids interact with one another.  The approach temperature difference is specified.  In this model, the pinchpoint must occur at either the hot or cold end; this model will not work if there is a chance that the pinchpoint will occur within the heat exchanger.  The procedure supports real fluids, ideal gas, incompressible, or brines on either side.  See HeatExchanger3_CL for a model that calculates the heat transfer coefficients to determine the heat exchanger performance.

 

Inputs:

 F_H$: hot fluid string identifier

 C_H: concentration of hot fluid - only necessary when hot fluid is brine, otherwise set C_H=0

 m_dot_H: mass flow rate of hot fluid (kg/s or lbm/hr)

 h_H_in: inlet specific enthalpy of hot fluid (J/kg, kJ/kg, or Btu/lbm)

 P_H_in: inlet pressure of hot fluid (bar, atm, Pa, kPa, MPa)

 F_C$: cold fluid string identifier

 C_C: concentration of cold fluid - only necessary when cold fluid is brine, otherwise set C_C=0

 m_dot_C: mass flow rate of cold fluid (kg/s or lbm/hr)

 h_C_in: inlet specific enthalpy of cold fluid (J/kg, kJ/kg, or Btu/lbm)

 P_C_in: inlet pressure of cold fluid (bar, atm, Pa, kPa, MPa)

 DT: approach temperature difference (K, C, R, or F)

 DPoverP_H: pressure drop normalized by absolute pressure on hot side (-)

 DPoverP_C: pressure drop normalized by absolute pressure on cold side (-)

 

Outputs:

 h_H_out: outlet specific enthalpy of hot fluid (J/kg, kJ/kg, or Btu/lbm)

 P_H_out: outlet pressure of hot fluid (bar, atm, Pa, kPa, MPa)

 h_C_out: outlet specific enthalpy of cold fluid (J/kg, kJ/kg, or Btu/lbm)

 P_C_out: outlet pressure of cold fluid (bar, atm, Pa, kPa, MPa)

 Q_dot: heat transfer rate from hot to cold (W, kW or Btu/hr)

 eff: effectiveness (-)

 

Example: 

$Load Component Library

$UnitSystem SI Mass J K Pa

F_H$='CarbonDioxide'

m_dot_H=0.1 [kg/s]

T_H_in=380 [K]  

P_H_in=4e6 [Pa]

h_H_in=enthalpy(F_H$,T=T_H_in,P=P_H_in)

m_dot_C=0.03 [kg/s]

T_C_in=300 [K]

P_C_in=6e6 [Pa]

C_C=10 [%]

h_C_in=enthalpy(F_C$,T=T_C_in,C=C_C,P=P_C_in)

F_C$='PG'

DT=5 [K]

DPoverP_H=0.01

DPoverP_C=0.01

Call heatexchanger2_cl(F_H$, 0, m_dot_H, h_H_in, P_H_in, F_C$, C_C, m_dot_C, h_C_in, &

 P_C_in, DT, DPoverP_H, DPoverP_C: h_H_out, P_H_out, h_C_out, P_C_out, Q_dot, eff)

 

{Solution:

h_H_out = -36618 [J/kg]

P_H_out = 3.960e6 [Pa]

h_C_out = 384988 [J/kg]

P_C_out = 5.940e6 [Pa]

Q_dot = 8544 [W], 

eff = 0.9271} 

 

Index