Components.TubeFinHEX
Tube-fin heat exchanger with refrigerant side and moist-air side.
The refrigerant side enters at refPort_a and leaves at refPort_b; m_flow > 0 means flow enters refPort_a. It is split into n_flows_distributor parallel circuits, each a discretised StraightPipe. The air side enters at airPort_a and leaves at airPort_b (m_flow > 0 means flow enters airPort_a) and crosses the same number of HEXCrossflow elements coupled to the refrigerant through a shared one-temperature wall. Supply refrigerant friction, two-phase heat- transfer, and air-side fin/tube geometry through the ref** and air** / airflow** parameters; ref_medium_data must be a refrigerant medium and air*medium_data a moist-air medium.
Usage
HVACComponents.Components.TubeFinHEX(ref_p_in_start, ref_p_out_start, ref_h_in_start, ref_h_out_start, ref_m_flow_start, ref_length, ref_diameter, ref_roughness=2e-5, ref_height_ab=0.0, ref_dp_nominal, ref_m_flow_nominal, ref_K_dp, ref_dp_exp, ref_alpha0, ref_alpha_vap, ref_alpha_2ph, ref_alpha_liq, ref_xdot_1, ref_xdot_2, ref_medium_data, air_p_in_start, air_p_out_start, air_T_in_start, air_T_out_start, air_Xi_in_start, air_Xi_out_start, air_m_flow_start, air_Q_start, wall_T_in_start, wall_T_out_start, wall_cp, wall_m, air_A, air_d0, air_delta, air_S_t, air_S_l, air_At_tube, air_Af_tube, air_htc_nominal, air_CF_MassTransfer, air_CF_HeatTransfer, air_kfin, air_Ka, air_k_mair, air_rho_constant, air_medium_data, airflow_A=air_A, airflow_d0=air_d0, airflow_delta=air_delta, airflow_S_t=air_S_t, airflow_S_l=air_S_l, airflow_At_tube=air_At_tube, airflow_Af_tube=air_Af_tube, airflow_htc_nominal=air_htc_nominal, airflow_CF_MassTransfer=air_CF_MassTransfer, airflow_CF_HeatTransfer=air_CF_HeatTransfer, airflow_kfin=air_kfin, airflow_Ka=air_Ka, airflow_k_mair=air_k_mair, airflow_rho_constant=air_rho_constant, airflow_p_in_start=air_p_in_start, airflow_p_out_start=air_p_out_start, airflow_m_flow_start=air_m_flow_start, airflow_T_in_start=air_T_in_start, airflow_T_out_start=air_T_out_start, airflow_Xi_in_start=air_Xi_in_start, airflow_Xi_out_start=air_Xi_out_start, airflow_Q_start=air_Q_start, airflow_eta_fin_start=0.8, airflow_Qdot_lat_start, airflow_Qdot_sens_start, airflow_xsat_w_start, airflow_eta_start, airflow_psat_w_start, airflow_psat_w_1K_start, airflow_xsat_w_1K_start, airflow_der_xsat_w_dT_start, airflow_mtc_start, airflow_dgradient_start, airflow_heff_start, airflow_h_in_start, airflow_h_out_start, airflow_mcond_flow_start, airflow_d_mean_start, airflow_Q_water_start, airflow_cp_mean_start)
Parameters:
| Name | Description | Units | Default value |
|---|---|---|---|
n_seg | Number of axial segments per circuit (currently informational) | – | 4 |
n_tube | Number of refrigerant tubes per circuit (currently informational) | – | 1 |
n_flows_distributor | Number of parallel refrigerant circuits and air-side cross-flow elements | – | 4 |
ref_model_structure | Staggered-grid model structure for each refrigerant circuit | – | HVACComponents.ModelStructure.av_b() |
ref_p_in_start | Initial refrigerant inlet pressure [Pa] | Pa | |
ref_p_out_start | Initial refrigerant outlet pressure [Pa] | Pa | |
ref_h_in_start | Initial refrigerant inlet specific enthalpy [J/kg] | J/kg | |
ref_h_out_start | Initial refrigerant outlet specific enthalpy [J/kg] | J/kg | |
ref_m_flow_start | Initial total refrigerant mass flow [kg/s] | kg/s | |
ref_length | Length of each refrigerant circuit [m] | m | |
ref_diameter | Refrigerant tube inner diameter [m] | m | |
ref_roughness | Refrigerant tube wall roughness [m] | m | 0.00002 |
ref_height_ab | Elevation difference along a refrigerant circuit (port_b above port_a) [m] | m | 0 |
ref_dp_nominal | Nominal refrigerant-side pressure drop for the friction correlation [Pa] | Pa | |
ref_m_flow_nominal | Nominal refrigerant mass flow for the friction correlation [kg/s] | kg/s | |
ref_K_dp | Refrigerant friction-correlation gain coefficient | – | |
ref_dp_exp | Refrigerant friction-correlation exponent | – | |
ref_alpha0 | Reference refrigerant heat-transfer coefficient [W/(m^2.K)] | – | |
ref_alpha_vap | Refrigerant vapor-phase heat-transfer coefficient [W/(m^2.K)] | – | |
ref_alpha_2ph | Refrigerant two-phase heat-transfer coefficient [W/(m^2.K)] | – | |
ref_alpha_liq | Refrigerant liquid-phase heat-transfer coefficient [W/(m^2.K)] | – | |
ref_xdot_1 | Lower vapor-quality blending bound between liquid and two-phase [-] | – | |
ref_xdot_2 | Upper vapor-quality blending bound between two-phase and vapor [-] | – | |
ref_medium_data | Refrigerant medium properties | – | |
air_p_in_start | Initial air inlet pressure [Pa] | Pa | |
air_p_out_start | Initial air outlet pressure [Pa] | Pa | |
air_T_in_start | Initial air inlet temperature [K] | K | |
air_T_out_start | Initial air outlet temperature [K] | K | |
air_Xi_in_start | Initial air inlet water-vapor mass fraction [-] | – | |
air_Xi_out_start | Initial air outlet water-vapor mass fraction [-] | – | |
air_m_flow_start | Initial total air mass flow [kg/s] | kg/s | |
air_Q_start | Initial total air-side heat flow [W] | – | |
wall_T_in_start | Initial wall temperature at the refrigerant inlet end [K] | K | |
wall_T_out_start | Initial wall temperature at the refrigerant outlet end [K] | K | |
wall_cp | Wall material specific heat capacity [J/(kg.K)] | J/(kg.K) | |
wall_m | Total wall mass [kg] | kg | |
air_A | Air-side total heat-transfer surface area per element [m^2] | – | |
air_d0 | Tube outer diameter on the air side [m] | – | |
air_delta | Fin thickness [m] | – | |
air_S_t | Transverse tube pitch [m] | – | |
air_S_l | Longitudinal tube pitch [m] | – | |
air_At_tube | Bare-tube surface area per element [m^2] | – | |
air_Af_tube | Fin surface area per element [m^2] | – | |
air_htc_nominal | Nominal air-side heat-transfer coefficient [W/(m^2.K)] | – | |
air_CF_MassTransfer | Air-side mass-transfer correction factor | – | |
air_CF_HeatTransfer | Air-side heat-transfer correction factor | – | |
air_kfin | Fin thermal conductivity [W/(m.K)] | – | |
air_Ka | Air-side mass-transfer scaling constant | – | |
air_k_mair | Moist-air molar mass constant used in psychrometrics | – | |
air_rho_constant | Constant air density used in dry-air evaluations [kg/m^3] | – | |
air_medium_data | Moist-air medium properties | – | |
airflow_A | Air-side heat-transfer surface area per element [m^2] (defaults to air_A) | – | air_A |
airflow_d0 | Tube outer diameter on the air side [m] (defaults to air_d0) | – | air_d0 |
airflow_delta | Fin thickness [m] (defaults to air_delta) | – | air_delta |
airflow_S_t | Transverse tube pitch [m] (defaults to air_S_t) | – | air_S_t |
airflow_S_l | Longitudinal tube pitch [m] (defaults to air_S_l) | – | air_S_l |
airflow_At_tube | Bare-tube surface area per element [m^2] (defaults to air_At_tube) | – | air_At_tube |
airflow_Af_tube | Fin surface area per element [m^2] (defaults to air_Af_tube) | – | air_Af_tube |
airflow_htc_nominal | Nominal air-side heat-transfer coefficient [W/(m^2.K)] (defaults to air_htc_nominal) | – | air_htc_nominal |
airflow_CF_MassTransfer | Air-side mass-transfer correction factor (defaults to air_CF_MassTransfer) | – | air_CF_MassTransfer |
airflow_CF_HeatTransfer | Air-side heat-transfer correction factor (defaults to air_CF_HeatTransfer) | – | air_CF_HeatTransfer |
airflow_kfin | Fin thermal conductivity [W/(m.K)] (defaults to air_kfin) | – | air_kfin |
airflow_Ka | Air-side mass-transfer scaling constant (defaults to air_Ka) | – | air_Ka |
airflow_k_mair | Moist-air molar mass constant (defaults to air_k_mair) | – | air_k_mair |
airflow_rho_constant | Constant air density used in dry-air evaluations [kg/m^3] (defaults to air_rho_constant) | – | air_rho_constant |
airflow_p_in_start | Initial air inlet pressure used inside the HEXCrossflow elements [Pa] | Pa | air_p_in_start |
airflow_p_out_start | Initial air outlet pressure used inside the HEXCrossflow elements [Pa] | Pa | air_p_out_start |
airflow_m_flow_start | Initial air mass flow per circuit-shared element [kg/s] | kg/s | air_m_flow_start |
airflow_T_in_start | Initial air inlet temperature inside the HEXCrossflow elements [K] | K | air_T_in_start |
airflow_T_out_start | Initial air outlet temperature inside the HEXCrossflow elements [K] | K | air_T_out_start |
airflow_Xi_in_start | Initial air inlet water-vapor mass fraction [-] | – | air_Xi_in_start |
airflow_Xi_out_start | Initial air outlet water-vapor mass fraction [-] | – | air_Xi_out_start |
airflow_Q_start | Initial air-side heat flow per element [W] | W | air_Q_start |
airflow_eta_fin_start | Initial fin efficiency [-] (solver guess) | – | 0.8 |
airflow_Qdot_lat_start | Initial latent heat flow per element [W] (solver guess) | – | |
airflow_Qdot_sens_start | Initial sensible heat flow per element [W] (solver guess) | – | |
airflow_xsat_w_start | Initial wall-side saturation humidity ratio [-] (solver guess) | – | |
airflow_eta_start | Initial dehumidification effectiveness [-] (solver guess) | – | |
airflow_psat_w_start | Initial wall-side saturation pressure [Pa] (solver guess) | – | |
airflow_psat_w_1K_start | Initial wall-side saturation pressure 1 K above the wall temperature [Pa] (solver guess) | – | |
airflow_xsat_w_1K_start | Initial wall-side saturation humidity ratio 1 K above the wall temperature [-] (solver guess) | – | |
airflow_der_xsat_w_dT_start | Initial derivative of saturation humidity ratio with respect to temperature [1/K] (solver guess) | – | |
airflow_mtc_start | Initial mass-transfer coefficient [kg/(m^2.s)] (solver guess) | – | |
airflow_dgradient_start | Initial humidity-ratio gradient driving condensation [-] (solver guess) | – | |
airflow_heff_start | Initial effective heat-transfer coefficient including fin efficiency [W/(m^2.K)] (solver guess) | – | |
airflow_h_in_start | Initial air inlet specific enthalpy used inside the HEXCrossflow elements [J/kg] | J/kg | |
airflow_h_out_start | Initial air outlet specific enthalpy used inside the HEXCrossflow elements [J/kg] | J/kg | |
airflow_mcond_flow_start | Initial condensate mass flow per element [kg/s] (solver guess) | kg/s | |
airflow_d_mean_start | Initial mean air density used in the HEXCrossflow elements [kg/m^3] (solver guess) | – | |
airflow_Q_water_start | Initial heat flow into condensate per element [W] (solver guess) | W | |
airflow_cp_mean_start | Initial mean air specific heat capacity [J/(kg.K)] (solver guess) | – |
Connectors
refPort_a- (FluidPort)refPort_b- (FluidPort)airPort_a- (MoistAirFluidPort)airPort_b- (MoistAirFluidPort)
Variables
| Name | Description | Units |
|---|---|---|
dP_ref_hx | Total refrigerant-side pressure drop refPort_a - refPort_b [Pa] | Pa |
Q_tot | Total heat-exchanger duty summed over all circuits [W] | W |
Qsen_tot | Total sensible heat-exchanger duty summed over all circuits [W] | W |
Qlat_tot | Total latent heat-exchanger duty summed over all circuits [W] | W |
Mtot | Total refrigerant mass inventory in all circuits [kg] | kg |
Tair_out | Air outlet temperature at airPort_b [K] | K |
mcond_out | Total condensate mass flow summed over all circuits [kg/s] | kg/s |