Thermal Simulation Report of Norpero 7 inch LED Headlight ...€¦ · Thermal Simulation Report of...

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Thermal Simulation Report of Norpero 7 inch LED Headlight

Eyer Series

Design: Jack Deng Date: 20140915


1. Thermal radiation judgment standard of the LED chips:

1.1 The maximum junction temperature of LED chips:

1.1.1 High and Low beam LED chips Model: OSRAM KW H2L531.

The maximum junction temperature : Tj=150℃.

1.1.2 Angel eyes LED chips: HL‐A‐3014H378W‐S1‐08‐HR1.

The maximum junction temperature: Tj=110℃.

1.2 Judgement standard:

Test in the 28℃ condition while the thermal stability:

Requirement: High and Low beam LED chips junction temperature < Tstandard=145℃=Tj150℃-5℃.

Requirement: Angel eyes LED chips junction temperature < Tstandard=105℃=Tj110℃-5℃.


2. Thermal simulation model and simulate conditions (High

beam and Angel eyes). 2.1 simulate conditions:

Project parameters

Product model 7’’ high low beam

led headlight

High beam LED chips

model

KW H2L531

High beam LED chips 2 PCS

High beam LED chips

junction temperature 150℃

High beam thermal

resistance

1.2K/W

High beam power 13.6W

Thermal power 10.88W

Angel eyes LED chips

model HL‐A‐

3014H378W‐S1

‐08‐HR1

Angel eyes LED chips 80 PCS



Angel eyes thermal

resistance

125K/W

Angel eyes power 3.6W

Thermal power 2.88W

The direction of gravity

Model

Inner Structure


Test temperature 28℃

2.2 Thermal simulation (High beam and Angel eyes). 2.2.1 Simulation process:

2.2.2 Conclusion:

The circuit board temperature of high beam:59.16℃；The circuit board temperature of angel eyes:72.57℃.

High beam LED junction temperature=59.16+13.6/2*1.2=67.32℃<Tstandard=145℃.So the thermal radiation is

fine.

Angel eyes LED junction temperature=72.57+3.6/80*125=78.195℃<Tstandard=105℃. So the thermal radiation is

Air flow inner The temperature distribution of the lights

Temperature ℃


fine.

3. Thermal simulation (Low beam and Angel eyes). 3.1 Simulations condition:

Project parameters

Product model 7’’ high low beam led

headlight

Low beam LED

chips model

KW H2L531

Low beam LED

chips

2 PCS

Low beam LED

chips junction

temperature

150℃

Low beam thermal

resistance

1.2K/W

Low beam power 13.6W

Thermal power 10.88W

Angel eyes LED

chips model HL‐A‐3014H378W

‐S1‐08‐HR1

Angel eyes LED

chips

80 PCS

Angel eyes LED

chips junction

temperature

110℃

Angel eyes thermal

resistance

125K/W


Thermal power 2.88W

Inner Structure

Direction of gravity

Model


Test temperature 28℃

3.2 Thermal simulation (Low beam and Angel eyes). 3.2.1 Simulation process:

3.2.2 Conclusion:

The circuit board temperature of high beam:61.51℃；The circuit board temperature of angel eyes:71.67℃.

Low beam LED junction temperature=61.51+13.6/2*1.2=69.67℃<Tstandard=145℃. So the thermal radiation is

fine.


Air flow inner The temperature distribution of the lights

Temperature ℃


fine.

4. Thermal simulation (High, Low beam and Angel eyes). 4.1 Simulation condition: Project parameters

Product model 7’’ high low beam led

headlight

High and Low beam

LED chips model

KW H2L531

High and Low beam

LED chips

2 PCS

High and Low beam

LED chips junction

temperature

150℃

High and Low beam

thermal resistance

1.2K/W

High beam power 13.6W


High beam Thermal power

10.88W

Low beam Thermal power

10.88W


model HL‐A‐3014H378W‐S1‐08‐HR1

Angel eyes LED chips 80 PCS



Angel eyes thermal

resistance

125K/W


Thermal power 2.88W

Direction of gravity

Model

Inner structure


Initial temperature 28℃

4.2 Thermal simulation (High, Low beam and Angel eyes). 4.2.1 Simulation process:

4.2.2 Conclusion:

The circuit board temperature of high beam:73.91℃;The circuit board temperature of low beam:75.79℃;The light

board temperature of angel eyes:85.57℃.

High beam LED junction temperature=73.91+13.6/2*1.2=80.71℃<Tstandard=145℃. So the thermal radiation is

fine.

Low beam LED junction temperature=75.79+13.6/2*1.2=82.59℃<Tstandard=145℃. So the thermal radiation is

fine


flow trajectories The temperature contoured of the lights

Temperature ℃


fine.

5. Experimental Verification. 5.1 Goal:

1) Verify the thermal radiation.

2) Compare the simulation result to the realistic.

3) Sample for test:

Model: 7 inch high low beam led headlight.

High beam LED chips: OSRAM KW H2L531, 2PCS; Low beam LED chips: OSRAM KW H2L531, 2PCS

Angel eyes LED chips: HL A 3014H378W S1 08 HR1, 80PCS


5.2 Experimental test (High beam and Angel eyes). 5.2.1 Working conditions test:

Front side

Input Volt and current

Condition temperature and Humidity

Working conditions test

(High beam and Angel eyes)


5.2.2 Experimental test (High beam and Angel eyes). Tested Results:

Project Results

Sample High beam

+Angel eyes

Input current 1.72A

Input volt 12V

Input power 20.64W

High beam

power

13.39W

Angel eyes

power

3.65W

The initial

temperature of

the condition

28℃

High beam

thermal

resistance

1.2K/W

Angel eyes

thermal

resistance

125K/W

High beam LED

chips junction

temperature

67.73℃

Angel eyes LED

chips junction

temperature

74.51℃

Test points and results


5.3 Experimental test (Low beam and Angel eyes). 5.3.1 Working conditions test:


(Low beam and angel eyes) Condition temperature and Humidity

Input Volt and current

Front side


5.3.2 Experimental test (Low beam and Angel eyes). Tested Results

Project Result

Sample Low beam +Angel

eyes

Input current 1.72A

Input volt 12V

Input power 20.47W

Low beam

power

13.48W

Angel eyes

power

3.65W

The initial

temperature of

the condition

28℃

Low beam

thermal

resistance

1.2K/W

Angel eyes

thermal

resistance

125K/W

Low beam LED

chips junction

temperature

72.19℃

Angel eyes LED

chips junction

temperature

72.81℃



5.4 Experimental test (High, Low beam and Angel eyes). 5.4.1 Working conditions test:

Front side


(High beam, Low beam and angel eyes)

Condition temperature and Humidity

Input current


5.4.2 Experimental test (High, Low beam and Angel eyes).

Tested Results: Project Result

Sample High+low beam

+Angel eyes

Input current 3.06A

Input volt 12V

Input power 36.72W

Hihg beam 13.39W



The initial

temperature of the

condition

28℃

High beam

thermal resistance

1.2K/W

Low beam

thermal resistance

1.2K/W

Angel eyes

thermal resistance

125K/W

Low beam LED

chips junction

temperature

84.23℃

Low beam LED

chips junction

temperature

87.79℃

Angel eyes LED

chips junction

temperature

89.30℃



6. Data collection In 28℃ tested condition: NO. Function Experimental

Input current

(A)

Input volt

(V)

LED

power(W)

Thermal

resistance

(K/W)

Temperature of

Circuit board

(℃)

LED chips junction

temperature

(℃)

Working condition 1. High beam 1.72 12.0 13.39 1.20 59.7 67.73

Angel eyes 3.65 125 68.8 74.51

Working condition 2. Low beam 1.72 11.9 13.48 1.20 64.1 72.19

Angel eyes 3.65 125 67.1 72.81


Low beam 13.48 1.20 79.7 97.79

Angel eyes 3.65 1.25 83.6 89.30

NO. Function Simulation

Input current

(A)

Input volt

(V)

LED

power(W)

Thermal power

(K/W)

Temperature of

Circuit board

(℃)

LED chips junction

temperature

(℃)


Angel eyes 3.60 2.88 72.57 78.195


Angel eyes 3.60 2.88 71.67 77.295


Low beam 13.60 10.88 75.79 82.59

Angel eyes 3.60 2.88 85.57 91.20


The test result in 55℃ working condition calculated base on the above tested result: NO. Function Experimental

Input current

(A)

Input volt

(V)

LED

power(W)

Thermal

resistance

(K/W)

Temperature of

Circuit board

(℃)

LED chips junction

temperature

(℃)


Angel eyes 3.65 125 95.80 101.51


Angel eyes 3.65 125 94.10 99.81


Low beam 13.48 1.20 106.70 124.79

Angel eyes 3.65 1.25 110.60 116.30

Conclusion: 1. The experimental tested results of these three working condition were close to the simulative results in the 28℃ working condition.

2. The tested result of angel eyes were lower than the simulative results as the decorative component were chrome-plated to help

radiating.

3. The all LED chips Junction temperature TJ<Tstandard in 28℃ working condition.

4. The LED chips Junction temperature calculated in the Working condition 3:

High beam LED chips Junction temperature: 84.23+(55-28)=111.23℃<Tstandard=145℃, thermal radiation is ok.

Low beam LED chips Junction temperature: 97.79+(55-28)=124.79℃<Tstandard=145℃, thermal radiation is ok.

Angel eyes LED chips Junction temperature: 89.30+(55-28)=116.30℃> Tstandard=105℃, thermal radiation is insufficient.

5. Suggest: when the High low beam were on the angel eyes should be off.


Thank you!

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