from dataclasses import dataclass
from enum import Enum
[docs]
@dataclass
class ThermalCoeff:
# Convective heat transfer coefficients (e.g. solid-fluid)
h_water_w_per_m2k: float = 3000.0 # Internal pipe – water to pipe wall [W/m²K]
h_surface_w_per_m2k: float = 200.0 # To ambient air [W/m²K]
h_channel_w_per_m2k: float = 100.0 # To channel wall [W/m²K]
h_soil_w_per_m2k: float = 3.0 # To surrounding soil [W/m²K]
# Conductivity coefficients (e.g. conduction through the materials)
k_pipe_w_per_mk: float = 43.0 # Thermal conductivity of the pipe material [W/mK]
k_ins_w_per_mk: float = 0.03 # Normal insulation [W/mK]
k_ins_damaged_w_per_mk: float = 0.03 # Damaged insulation (same value for now) [W/mK]
[docs]
class PipeSectionLocation(Enum):
loc1 = "channel"
loc2 = "surface"
loc3 = "soil"
"""
PIPE SECTION PROPERTIES
Physical properties of the pipeline materials and environment.
Sources:
- Water-to-steel convection: Engineers Edge
- Steel conductivity: Engineering Toolbox
- Polyurethane insulation conductivity: Engineering Toolbox
── Water-to-pipe convection ─────────────────────────────────────────────────
h_water_w_per_m2k = 3000 # internal water-side heat transfer coefficient [W/m²K]
k_pipe_w_per_mk = 43 # thermal conductivity of steel pipe [W/mK]
── Insulation ───────────────────────────────────────────────────────────────
k_ins_w_per_mk = 0.03 # thermal conductivity of new insulation (PUR) [W/mK]
k_ins_damaged_w_per_mk = 0.03 # thermal conductivity of damaged insulation (same) [W/mK]
── External convection coefficients ─────────────────────────────────────────
h_ambent_w_per_m2k = 200 # external air-side heat transfer coefficient (outdoor) [W/m²K]
h_channel_w_per_m2k = 100 # in-channel natural convection estimate [W/m²K]
h_soil_w_per_m2k = 3 # buried pipes, rough guess for soil convection [W/m²K]
"""