battery_cooling.py

class openconcept.thermal.battery_cooling.LiquidCooledBattery(**kwargs)

Bases: Group

A battery with liquid cooling

Inputs:

  • q_in (float) – Heat produced by the operating component (vector, W)

  • mdot_coolant (float) – Coolant mass flow rate (vector, kg/s)

  • T_in (float) – Instantaneous coolant inflow temperature (vector, K)

  • battery_weight (float) – Battery weight (scalar, kg)

  • n_cpb (float) – Number of cells long per “bandolier” actual count is 2x (scalar, default 82, Tesla)

  • t_channel (float) – Thickness (width) of the cooling channel in the bandolier (scalar, default 1mm)

  • T_initial (float) – Initial temperature of the battery (only required in thermal mass mode) (scalar, K)

  • duration (float) – Duration of mission segment, only required in unsteady mode

Outputs:

  • T_out (float) – Instantaneous coolant outlet temperature (vector, K)

  • T (float) – Battery volume averaged temperature (vector, K)

  • T_core (float) – Battery core temperature (vector, K)

  • T_surface (float) – Battery surface temperature (vector, K)

Options:

  • num_nodes (int) – Number of analysis points to run

  • quasi_steady (bool) – Whether or not to treat the component as having thermal mass num_nodes : float The number of analysis points to run

  • coolant_specific_heat (float) – Specific heat of the coolant (J/kg/K) (default 3801, glycol/water)

  • fluid_k (float) – Thermal conductivity of the coolant (W/m/K)

  • nusselt (float) – Nusselt number of the coolant channel (default 7.54 for uniform surf temp)

  • cell_kr (float) – Thermal conductivity of the cell in the radial direction (W/m/k)

  • cell_diameter (float) – Battery diameter (default 21mm for 2170 cell)

  • cell_height (float) – Battery height (default 70mm for 2170 cell)

  • cell_mass (float) – Battery weight (default 70g for 2170 cell)

  • cell_specific_heat (float) – Mass average specific heat of the battery (default 900, LiIon cylindrical cell)

  • battery_weight_fraction (float) – Fraction of battery by weight that is cells (default 0.72 knocks down Tesla by a bit)

class openconcept.thermal.battery_cooling.BandolierCoolingSystem(**kwargs)

Bases: ExplicitComponent

Computes battery heat transfer for a parameteric battery based on Tesla’s Model 3 design.

Assumptions: Heat generated uniformly in the cell Weight per cell and thermal resistance stay constant even as specific energy varies parametrically (this means that cell count is constant with pack WEIGHT, not pack ENERGY as technology improves) Cylindrical cells attached to Tesla-style thermal ribbon Liquid cooling Heat transfer through axial direction only (not baseplate) 2170 cells (21 mm diameter, 70mm tall) Battery thermal model assumes unsteady cell temperature, quasi-steady temperature gradients

Note

See the LiquidCooledBattery for a group that already integrates this component with a battery.

Inputs:

  • q_in (float) – Heat generation rate in the battery (vector, W)

  • T_in (float) – Coolant inlet temperature (vector, K)

  • T_battery (float) – Volume averaged battery temperature (vector, K)

  • mdot_coolant (float) – Mass flow rate of coolant through the bandolier (vector, kg/s)

  • battery_weight (float) – Weight of the battery (overall). Default 100kg (scalar)

  • n_cpb (float) – Number of cells long per “bandolier” actual count is 2x (scalar, default 82, Tesla)

  • t_channel (float) – Thickness (width) of the cooling channel in the bandolier (scalar, default 1mm)

Outputs:

  • dTdt (float) – Time derivative dT/dt (Tbar in the paper) (vector, K/s)

  • T_surface (float) – Surface temp of the battery (vector, K)

  • T_core (float) – Center temp of the battery (vector, K)

  • q (float) – Heat transfer rate from the motor to the fluid (vector, W)

  • T_out (float) – Outlet fluid temperature (vector, K)

Options:

  • num_nodes (float) – The number of analysis points to run

  • coolant_specific_heat (float) – Specific heat of the coolant (J/kg/K) (default 3801, glycol/water)

  • fluid_k (float) – Thermal conductivity of the coolant (W/m/K)

  • nusselt (float) – Nusselt number of the coolant channel (default 7.54 for uniform surf temp)

  • cell_kr (float) – Thermal conductivity of the cell in the radial direction (W/m/k)

  • cell_diameter (float) – Battery diameter (default 21mm for 2170 cell)

  • cell_height (float) – Battery height (default 70mm for 2170 cell)

  • cell_mass (float) – Battery weight (default 70g for 2170 cell)

  • cell_specific_heat (float) – Mass average specific heat of the battery (default 900, LiIon cylindrical cell)

  • battery_weight_fraction (float) – Fraction of battery by weight that is cells (default 0.72 knocks down Tesla by a bit)