GROUP 8 REPORT TOPIC heating iron bars with heat

The current induced in the coil generates heat, and as the temperature increases, the conductivity of the copper wire also changes.. One challenge in induction heating is that high curre

GROUP 8 REPORT

TOPIC: Heating Iron Bars With Heat

1. Global Definitions

Parameters 1

2. Model 1 (mod1)

Definitions

Geometry 1

Materials

Induction Heating (ih)

Mesh 1

3. Study 1

Frequency-Transient

4 Results

Data Sets

Tables

Plot Groups

This is a simulation inspired by a high-rise kiln Here, we use induction coil and metal ingot to perform the simulation The heating process for the workpiece is based on the phenomenon of electromagnetic induction The current induced in the coil generates heat, and as the temperature increases, the conductivity of the copper wire also changes Heating caused by induced current is called induced heating One challenge in induction heating is that high currents in the induction coils require active cooling This can be achieved by emptying the coil conductors and circulating water inside Even for a rather modest flow rate, the coolant flow becomes highly turbulent making heat transfer between the conductor and the liquid very efficient This model illustrates a simplified water cooling model based on the assumption of turbulent flow and instantaneous mixing For mechanical support and electrical insulation, the cylinder and coil are embedded with FR4 composite material

Model Definition

The system to be solved is given by

jωσ( T )A +ωσ( T )A + ∇×( μ -1 ∇ × A) = 0

where ρ is the density, Cp is the specific heat capacity, k is the thermal conductivity, and Q is the inductive heating

The electric conductivity of copper, σ, is given by the expression

σ¿

[ ρ o (1+α (1

T −T o))]))]]

Where ρ ois the resistivity at the reference temperature To = 293 K, α is the temperature coefficient of the resistivity, and T is the actual temperature in the domain The time average of the inductive heating over one period, is given by

Q= 1

2 σ|E|2

The coil conductor is cooled by a turbulent water flow in an internal cooling channel

This is emulated by a combination of a high effective thermal conductivity and

a homogenized out-of-plane convective loss term:

dM Cp (T ¿−T ))]

Q

c= dt 2 πrArA

where dM

dt is the water mass flow, Tin is the water inlet temperature, r is the

radial coordinate and A is the cross-section area of the cooling channel

Global Definitions

Parameters 1

Parameters

r0 1.754e-8[ohm*m] Resistivity at T=T0

alpha 0.0039[1/K] Temperature coefficient

Mt 1[kg/min] Cooling water mass flow rate Tin 10[degC] Cooling water inlet temperature

Model 1 (mod1)

Definitions

Coordinate Systems

Boundary System 1

Coordinate system type Boundary system

Geometry 1

Geometry 1

units

Length unit m

Angular unit deg

FR4 (Circuit Board)

FR4 (Circuit Board)

Selection

Copper

Selection

level

3

Water, liquid

Water, liquid

Selection

Geometric entity level Domain

Selection Domain 4

Induction Heating (ih)

Induction Heating

Features

Induction Heating Model 1

Electromagnetic Heat Source 1

Boundary Electromagnetic Heat Source 1

Axial Symmetry 1

Magnetic Insulation 1

Thermal Insulation 1

Initial Values 1

Induction Heating Model 3

Single-Turn Coil Domain 1

Temperature 1

Heat Source 1

Mesh 1

Mesh 1

Study 1

Frequency-Transient

Mesh selection

Geometry Mesh

Geometry 1 (geom1) mesh1

Physics selection

Physics Discretization

Data Sets

Solution 1

Selection

Solution

Revolution 2D 1

Data

Name Value

set

Revolution layers

Start angle Revolution angle

Cut Point 2D 1

13

Name Value

set

Cut Plane 1

Data

Data set Revolution 2D 1

Plane data

Name Value

Plane type General

Advanced

Space variables {cpl1x, cpl1y}

Tables

Evaluation 2D

Interactive 2D values

Evaluation 2D

-5.55112e-17 -0.03553 0.10362 22.52961

14

Plot Groups

Temperature, 3D (ih)

Time=6000 Surface: Temperature (degC)

1D Plot Group 2

Point Graph: Temperature (K) Point Graph: Temperature (K)

15

2D Plot Group 3

Time=36000 Surface: Temperature (K)

2D Plot Group 4

Contour: Temperature (K) Surface: Temperature (K)