enex_analysis.heat_transfer

Heat transfer and fluid dynamics calculations.

Functions

TRIDIAG_MATRIX_ALGORITHM(a_M, a_P, a_E, a_W, b_P)

Solve tridiagonal matrix system using Thomas algorithm.

calc_LMTD_counter_flow(Th_in, Th_out, Tc_in, ...)

Calculate Log-Mean Temperature Difference for counter-flow heat exchanger.

calc_LMTD_parallel_flow(Th_in, Th_out, ...)

Calculate Log-Mean Temperature Difference for parallel-flow heat exchanger.

calc_UA_tank_arr(arr_D_in, arr_D_out, arr_L, ...)

Calculate thermal conductance (UA) of a multi-layer cylindrical tank.

calc_h_vertical_plate(T_s, T_inf, L[, ...])

Calculate natural convection heat transfer coefficient for a vertical plate.

calc_simple_tank_UA([r0, H, x_shell, x_ins, ...])

Calculate simple tank UA value.

darcy_friction_factor(Re, e, d[, is_active])

Calculate the Darcy friction factor.
enex_analysis.heat_transfer.darcy_friction_factor(Re, e, d, is_active=True)[source]

Calculate the Darcy friction factor.

Uses Haaland equation.

Parameters:

  • Re (float) – Reynolds number.

  • e (float) – Surface roughness [m].

  • d (float) – Diameter [m].

  • is_active (bool, optional) – If False, returns np.nan.

Returns:

Friction factor.

Return type:

float

enex_analysis.heat_transfer.calc_h_vertical_plate(T_s, T_inf, L, fluid='Air', is_active=True)[source]

Calculate natural convection heat transfer coefficient for a vertical plate.

Parameters:

  • T_s (float) – Surface temperature [K].

  • T_inf (float) – Fluid temperature [K].

  • L (float) – Characteristic length [m].

  • fluid (str, optional) – Fluid name. Default is ‘Air’.

  • is_active (bool, optional) – If False, returns np.nan.

Returns:

Heat transfer coefficient [W/m2K].

Return type:

float

enex_analysis.heat_transfer.calc_UA_tank_arr(arr_D_in, arr_D_out, arr_L, arr_k, h_in, h_out)[source]

Calculate thermal conductance (UA) of a multi-layer cylindrical tank.

Parameters:

  • arr_D_in (array_like or list) – Inner diameters of layers [m].

  • arr_D_out (array_like or list) – Outer diameters of layers [m].

  • arr_L (array_like or list) – Lengths of layers [m].

  • arr_k (array_like or list) – Thermal conductivities of layers [W/mK].

  • h_in (float) – Inner convection coefficient [W/m2K].

  • h_out (float) – Outer convection coefficient [W/m2K].

Returns:

Thermal conductance [W/K].

Return type:

float

enex_analysis.heat_transfer.calc_simple_tank_UA(r0=0.2, H=0.8, x_shell=0.01, x_ins=0.1, k_shell=25.0, k_ins=0.03, h_o=10.0)[source]

Calculate simple tank UA value.

Parameters:

  • r0 (float) – Tank radius [m]

  • H (float) – Tank height [m]

  • x_shell (float) – Shell thickness [m]

  • x_ins (float) – Insulation thickness [m]

  • k_shell (float) – Shell thermal conductivity [W/mK]

  • k_ins (float) – Insulation thermal conductivity [W/mK]

  • h_o (float) – External convective heat transfer coefficient [W/m²K]

Returns:

Tank UA value [W/K]

Return type:

float

enex_analysis.heat_transfer.calc_LMTD_counter_flow(Th_in, Th_out, Tc_in, Tc_out)[source]

Calculate Log-Mean Temperature Difference for counter-flow heat exchanger.

Parameters:

  • Th_in (float) – Hot stream inlet temp [K].

  • Th_out (float) – Hot stream outlet temp [K].

  • Tc_in (float) – Cold stream inlet temp [K].

  • Tc_out (float) – Cold stream outlet temp [K].

Returns:

LMTD [K].

Return type:

float

enex_analysis.heat_transfer.calc_LMTD_parallel_flow(Th_in, Th_out, Tc_in, Tc_out)[source]

Calculate Log-Mean Temperature Difference for parallel-flow heat exchanger.

Parameters:

  • Th_in (float) – Hot stream inlet temp [K].

  • Th_out (float) – Hot stream outlet temp [K].

  • Tc_in (float) – Cold stream inlet temp [K].

  • Tc_out (float) – Cold stream outlet temp [K].

Returns:

LMTD [K].

Return type:

float

enex_analysis.heat_transfer.TRIDIAG_MATRIX_ALGORITHM(a_M, a_P, a_E, a_W, b_P)[source]

Solve tridiagonal matrix system using Thomas algorithm.

Parameters:

  • a_M (list[float]) – Main diagonal (a_P in standard notation).

  • a_P (list[float]) – Not used directly, maintained for signature compatibility.

  • a_E (list[float]) – Upper diagonal.

  • a_W (list[float]) – Lower diagonal.

  • b_P (list[float]) – RHS vector.

Returns:

Solution vector.

Return type:

list[float]