Heat Transfer Calculator & Simulator

by

🚀 Heat Transfer Calculator & Simulator

HEAT TRANSFER

Multi-layer Composite Wall Heat Transfer Calculator & Real-time 1D Simulator
Real-time Numerical Heat Transfer Analysis in Progress

Wall & Boundary Condition Controls

Min: 50°C / Max: 600°C
°C
Min: -20°C / Max: 50°C
°C
mm
mm
mm

Wall Configuration Presets

Real-time Multi-layer Wall Temperature Gradient (Temperature Gradient Line)

Heat FluxHeat Flux – q”
256.4 W/m²
Total Thermal Resistance (R_tot)
1.500 m²·K/W
Overall Heat Transfer Coefficient (U-Value)
0.667 W/m²·K
Inner Surface Temperature (T_s,c)
20.4 °C
Outer Surface Temperature (T_s,h)
374.5 °C

Multi-layer Wall Total Thermal Resistance Formula

R = 1/h_h + Σ(L_i/k_i) + 1/h_c
Disclaimer: The calculation results of this simulator are provided for educational and reference purposes only. For actual product design or manufacturing, please verify with the latest engineering standards and official design codes. The integrity of the calculated values is not guaranteed, and the developer and this blog assume no liability for any direct or indirect damages arising from their use.
💡 💡 Quick User Guide
  1. Set fluid boundary temperatures: Set the hot fluid temperature (Tf,h) and cold fluid temperature (Tf,c).
  2. Design wall layers: Enter the materials (steel, concrete, red brick, glass wool insulation, etc.) and thicknesses (L) for the three layers making up the composite wall.
  3. Adjust convective heat transfer coefficients: Model convection resistance by setting the convective boundary layer coefficients (h) for the hot left side and cold right side.
  4. Analyze the temperature gradient diagram: Visually monitor which layer exerts dominant thermal resistance by observing the temperature drop slopes across the convective boundary layers and solid walls.
📚 Review Theoretical Formulas for Conduction and Convective Thermal Resistance in Multi-Layer Walls ▼

1. Theory of 1D Steady-State Heat Transfer

Thermal behavior in engineering insulation design, boiler walls, and heat exchanger tubes can be approximated as one-dimensional heat flow through multi-layered solids. Steady-state conditions refer to a hypothetical equilibrium state where temperatures at all points do not change over time. In this state, the heat rate flowing from the hot fluid through the wall to the cold fluid is conserved across all sections.

  • Convective Heat Transfer: The mechanism by which heat is transferred between a fluid and an adjacent solid interface through the combined action of molecular vibration and macroscopic fluid motion (Q = h·A·ΔT).
  • Conductive Heat Transfer: Heat is sequentially transferred by lattice vibrations of atoms/electrons within a substance without physical movement of the material itself (Fourier's Law: q'' = -k·dT/dx).

2. Thermal Network Analysis and Overall Heat Transfer Coefficient

When complex conduction and convection are linked in series, they can be easily analyzed as a Thermal Resistance Network by introducing the concept of resistance from electrical circuits.

① Individual Thermal Resistance Formulas (Based on Area A = 1 m²):

  • Convective boundary thermal resistance: R_conv = 1 / h  [K/W]
  • Solid conductive thermal resistance: R_cond = L / k  [K/W] (L: thickness m, k: thermal conductivity W/m·K)

② Total Thermal Resistance and Heat Flux (q''):

R_tot = (1 / h_h) + (L1 / k1) + (L2 / k2) + (L3 / k3) + (1 / h_c)  [m²·K/W]

q'' = Q / A = (T_f,h - T_f,c) / R_tot  [W/m²]

③ Calculating Node-by-Node Surface Temperature Drop: Just like electric potential difference, temperature drops in direct proportion as heat passes through each thermal resistance:

T_s,h = T_f,h - q'' × (1 / h_h)  [°C]

T_12 = T_s,h - q'' × (L1 / k1)  [°C]

Using these formulas, you can determine the interface temperatures of the composite wall to monitor whether the materials stay within safe thermal limits.

3. Characteristics and Thermal Conductivities of Key Engineering Insulation Materials

For efficient thermal management, insulation materials with extremely low thermal conductivity are placed in the middle layer of the wall.

  • Glass/Mineral Wool: With approximately k ≈ 0.035–0.045 W/m·K, it provides excellent high-temperature insulation performance and minimizes heat conduction by trapping air in micropores.
  • Red Brick: With k ≈ 0.7–0.8 W/m·K, it offers structural durability, but its heat loss prevention performance is more than 20 times lower than that of standard insulation.
  • Concrete: With k ≈ 1.3–1.5 W/m·K, it has very high thermal conductivity, making it a primary cause of winter condensation and thermal bridging.

Leave a Comment