Contents - index

HeatExchanger6_CL

HeatExchanger5_CL models a counterflow heat exchanger with any type of fluids except 'AirH2O'.  The model divides the heat exchanger into sub heat exchangers in order to capture the impact of fluid heat capacity variation.  HeatExchanger5_CL takes in the inlet conditions associated with the hot and cold flows and the effectiveness and returns the conductance and pinch point DT of the HX.

Inputs:

F_H\$ = hot fluid (can be anything but AirH2O)

C_H = concentration of solvent in hot fluid (used only for brines, otherwise ignored)

P_H_in = inlet pressure of hot fluid

h_H_in = enthalpy of hot fluid at inlet

m_dot_H = mass flow rate of hot fluid

F_C\$ = cold fluid (can be anything but AirH2O)

C_C = concentration of solvent in cold fluid (used only for brines, otherwise ignored)

P_C = inlet pressure of cold fluid

h_C_in = enthalpy of cold fluid at inlet

m_dot_C = mass flow rate of cold fluid

DT_pp = pinchpoint temperature difference of heat exchanger

DPoverP_H = pressure drop normalized by inlet pressure on hot side

DPoverP_C = pressure drop normalized by inlet pressure on cold side

N = number of sub heat exchanger (if set to any value <1 then default of N = 10 is used)

Outputs:

h_H_out = enthalpy of hot fluid leaving

h_C_out = enthalpy of cold fluid leaving

UA = conductance of heat exchanger

eff = effectiveness of heat exchanger

Example:

\$UnitSystem SI Mass J K Pa

\$VarInfo h_C_in, h_C_out, h_H_in, h_H_out Units=J/kg

\$VarInfo P_C_out, P_H_out units=Pa

\$VarInfo T_H_Out, T_C_out, DT_pp Units=K AltUnits=C

F_C\$='EG'

C_C=25 [%]

P_C_in=200e3 [Pa]

T_C_in = converttemp(C,K,20 [C])

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

DPoverP_C = 0.01

m_dot_C = 0.25 [kg/s]

F_H\$='Dowtherm_T'

P_H_in = 400e3 [Pa]

T_H_in = converttemp(C,K,110 [C])

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

C_H = 0

m_dot_H = 0.5 [kg/s]

DPoverP_H = 0.02

N = 10

DT_pp = 42 [K]

Call heatexchanger6_cl(F_H\$, C_H, P_H_in, h_H_in, m_dot_H, F_C\$, C_C, P_C_in, h_C_in, m_dot_C, DT_pp, DPoverP_H, DPoverP_C, N: h_H_out, h_C_out, UA, eff)

P_H_out = P_H_in*(1-DPoverP_H)

h_H_out = enthalpy(F_H\$,T=T_H_out, P=P_H_out)

P_C_out = P_C_in*(1-DPoverP_C)

h_C_out=enthalpy(F_C\$,P=P_C_out,T=T_C_out,C=C_C)

{Solution:

UA = 1036 [W/K]

eff = 0.5273

T_H_out = 340.3 [K] or 67.18 [C]

T_C_out = 341.2 [K] or 68.00 [C]}