coil

Package

Modules

coil_torch_system module

class CoilTorchSystem(**kwargs)[source]

Bases: System, Module

A coil system model implemented with PyTorch for gradient-based optimization.

This model represents a heating/cooling coil that transfers heat between air and water, calculating the required heating or cooling power based on air flow rate and temperature differences.

Mathematical Formulation

The heating/cooling power is calculated using the following equations:

For heating mode (when \(T_{in} < T_{out,set}\)):

\[P_{heat} = \dot{m}_{air} \cdot c_{p,air} \cdot (T_{out,set} - T_{in})\]
\[P_{cool} = 0\]

For cooling mode (when \(T_{in} \geq T_{out,set}\)):

\[P_{heat} = 0\]
\[P_{cool} = \dot{m}_{air} \cdot c_{p,air} \cdot (T_{in} - T_{out,set})\]
where:

  • \(P_{heat}\) is the heating power [W]

  • \(P_{cool}\) is the cooling power [W]

  • \(\dot{m}_{air}\) is the air flow rate [kg/s]

  • \(c_{p,air}\) is the specific heat capacity of air [J/(kg·K)]

  • \(T_{in}\) is the inlet air temperature [°C]

  • \(T_{out,set}\) is the outlet air temperature setpoint [°C]

Notes

Model Assumptions:

  • Perfect heat transfer (outlet temperature equals setpoint)

  • Constant specific heat capacity of air

  • No heat losses to the environment

  • No water-side calculations (focus on air-side performance)

Implementation Details:

  • If air flow rate is below threshold (1e-5 kg/s), both heating and cooling powers are set to zero

  • The model uses PyTorch tensors for gradient-based optimization

  • All calculations are performed in SI units

  • The specific heat capacity is stored as a non-trainable PyTorch parameter

do_step(secondTime, dateTime, step_size, stepIndex)[source]

Perform one step of the coil system simulation.

The model calculates heating/cooling power based on: - Air flow rate - Inlet air temperature - Outlet air temperature setpoint

If the air flow rate is zero, the output power is set to 0.

Return type:

None

initialize(start_time, end_time, step_size, simulator)[source]

Initialize the coil system.

Return type:

None

property config

Get the configuration of the coil system.

property input: dict

Get the input ports of the coil system.

Returns:

Dictionary containing input ports:

  • ”inletAirTemperature”: Inlet air temperature [°C]

  • ”outletAirTemperatureSetpoint”: Outlet air temperature setpoint [°C]

  • ”airFlowRate”: Air flow rate [kg/s]

Return type:

dict

property output: dict

Get the output ports of the coil system.

Returns:

Dictionary containing output ports:

  • ”heatingPower”: Heating power [W]

  • ”coolingPower”: Cooling power [W]

  • ”outletAirTemperature”: Outlet air temperature [°C]

Return type:

dict

property specificHeatCapacityAir: Parameter

Get the specific heat capacity of air.

Returns:

Specific heat capacity of air [J/(kg·K)].

Return type:

tps.Parameter