def flatesteam_feed(Q_feed, r_steam):
    """
    Calculates the flow rate steam of boiler.
    Parameters
    ----------
    Q_feed : float
        The heat load feed of heat exchanger, [W] [J/s]
    r_steam : float
        The heat vaporazation of dist [J/kg]
    Returns
    -------
    flatesteam_feed : float
        The flow rate steam of feed heat exchanger, [W] [J/s]
    References
    ----------
    Дытнерский, формула 2.3, стр.45
    """               
    return Q_feed / r_steam