Plasma arc welding¶

def requirement_electricity(output_amount, *,
                            welding_voltage, welding_current, vacuum_power,
                            welding_speed, number_of_seams, electrode_diameter,
                            ti64_density, ecoinvent):
    r"""Electricity exchange for welding ``output_amount`` kg of electrode.

    Specific energy per kg of welded electrode, with weld length per unit
    mass ``l`` from [`auxiliary_weld_length_per_mass`][acap_ti64.plasma_arc_welding.model.auxiliary_weld_length_per_mass]:

    \[ E = \frac{V\,I + p_\mathrm{vac}}{v}\, l, \qquad
       l = \frac{4\,N_\mathrm{seams}}{\rho_\mathrm{Ti64}\,\pi\,D_\mathrm{electrode}^{2}} \]

    The result is multiplied by ``output_amount`` and unit-converted to
    ``ecoinvent["unit"]`` (joule → kilowatt hour by default).

    Returns
    -------
    dict
        ``{**ecoinvent, "amount": ...}``.
    """
    l = auxiliary_weld_length_per_mass(number_of_seams, electrode_diameter, ti64_density)
    energy_J_per_kg = (welding_voltage * welding_current + vacuum_power) * (1.0 / welding_speed) * l
    amount = _dispatch.convert(energy_J_per_kg * output_amount, "joule", ecoinvent["unit"])
    return {**ecoinvent, "amount": amount}

def requirement_argon(output_amount, *,
                      argon_flow_rate, welding_speed, number_of_seams,
                      electrode_diameter, ti64_density, ecoinvent):
    r"""Argon exchange for welding ``output_amount`` kg of electrode.

    Continuous make-up flow during welding only (chamber back-fill is out of
    scope), with weld length per unit mass ``l`` from
    [`auxiliary_weld_length_per_mass`][acap_ti64.plasma_arc_welding.model.auxiliary_weld_length_per_mass]:

    \[ w_\mathrm{Ar} = \frac{r}{v}\, l \]

    Returns an exchange dict.
    """
    l = auxiliary_weld_length_per_mass(number_of_seams, electrode_diameter, ti64_density)
    argon_kg_per_kg = argon_flow_rate * (1.0 / welding_speed) * l
    amount = _dispatch.convert(argon_kg_per_kg * output_amount, "kilogram", ecoinvent["unit"])
    return {**ecoinvent, "amount": amount}

def requirement_titanium_sponge(output_amount, *, ti_mass_fraction, ecoinvent):
    r"""Ti-sponge exchange for welding ``output_amount`` kg of electrode.

    \[ m_\mathrm{Ti} = w_\mathrm{Ti}\, m \]
    """
    amount = _dispatch.convert(ti_mass_fraction * output_amount, "kilogram", ecoinvent["unit"])
    return {**ecoinvent, "amount": amount}

def requirement_aluminum(output_amount, *, al_mass_fraction, ecoinvent):
    r"""Aluminium-ingot exchange for welding ``output_amount`` kg of electrode.

    \[ m_\mathrm{Al} = w_\mathrm{Al}\, m \]
    """
    amount = _dispatch.convert(al_mass_fraction * output_amount, "kilogram", ecoinvent["unit"])
    return {**ecoinvent, "amount": amount}

def requirement_vanadium(output_amount, *, v_mass_fraction, vanadium_gwp,
                         ecoinvent):
    r"""Vanadium-attributable cradle-to-gate CO2 emission.

    \[ m_{\mathrm{CO_2}} = w_\mathrm{V}\, m\, \mathrm{GWP}_\mathrm{V} \]

    Ecoinvent does not carry a representative vanadium-metal activity,
    so the vanadium term is added as a direct fossil-CO2 biosphere flow
    sized by a literature cradle-to-gate GWP factor
    (Nuss & Eckelman 2014). The flow target in ``exchanges/*.yaml`` is
    ``Carbon dioxide, fossil`` with ``location: biosphere``.

    Parameters
    ----------
    output_amount : float or numpy.ndarray
        Mass of welded electrode produced (kg).
    v_mass_fraction : float or numpy.ndarray
        Vanadium mass fraction of Ti-6Al-4V (dimensionless).
    vanadium_gwp : float or numpy.ndarray
        Cradle-to-gate GWP100 of pure vanadium metal (kg CO2-eq / kg V).
    ecoinvent : dict
        Biosphere target dict, ``{name, location, unit}``.

    Returns
    -------
    dict
        ``{**ecoinvent, "amount": kg CO2 emitted to air per output_amount}``.
    """
    co2_kg = v_mass_fraction * output_amount * vanadium_gwp
    amount = _dispatch.convert(co2_kg, "kilogram", ecoinvent["unit"])
    return {**ecoinvent, "amount": amount}

def auxiliary_weld_length_per_mass(N_seams, D_electrode, rho_Ti64):
    r"""Meters of weld per kilogram of Ti-6Al-4V processed.

    \[ l = \frac{4\,N_\mathrm{seams}}{\rho_\mathrm{Ti64}\,\pi\,D_\mathrm{electrode}^{2}} \]

    The electrode rod length cancels in the per-mass normalisation.

    Parameters
    ----------
    N_seams : float or numpy.ndarray
    D_electrode : float or numpy.ndarray
        Electrode diameter (m).
    rho_Ti64 : float or numpy.ndarray
        Bulk density of Ti-6Al-4V (kg/m^3).

    Returns
    -------
    float or numpy.ndarray
        Weld length per kg of welded electrode (m/kg).
    """
    return 4.0 * N_seams / (rho_Ti64 * np.pi * D_electrode**2)