LW – 9354 Heat Pipe Thermal Performance Measurement Apparatus

To evaluate the performance of heat pipes, we have a state-of-the-art heat pipe tester provided from Long Win Science and Technology Corporation. It is equipped with a water-cooler circulating system, heating control system, attitude adjustment device, measurement system, data acquisition, and test analysis. With the attitude adjustment device, heat pipes can be tested at different angles and directions to evaluate the performance of heat pipes given different testing conditions.

Tests Available:

1. Thermal Performance Steady-State Test
2. Thermal Resistance Measurement at different Angles
3. Thermal Response Rate Measurements

Principle

The principle of the heat pipe testing equipment is to set a simulated heating source at one end of the heat pipe, and set a cooling device at the other end of the heat pipe to simulate the heat sink. We can then measure the temperature difference between the hot and cold ends of the heat pipe (∆T=Thavg − Tcavg) through the heat absorbed by the heat pipe (Q), the thermal resistance (R) and equivalent thermal conductivity (Keff) of the heat pipe can be calculated. We can evaluate the thermal performance steady-state of a heat pipe, thermal resistance measurement of a heat pipe at different angles and the thermal response rate of a heat pipe.

Specifications

Measurement Range:

• Maximum heat power: 90W
• 1.2 Based on the horizontal attitude, ±90° stepless adjustment, with digital angle display.

Measuring Instruments:

• Temperature measurement, including 4 sets of T-Type thermocouples and 1 set of resistance thermometer
• Heating end temperature Th
• Temperature at the condensing end Tc1
• Temperature of cooling water at the water block Tcw
• Condensing end heating temperature Tc2
• Angle display of attitude platform

Test Equipment:

• Programmable power supply: 0~30V DC, 3A, 90W
• Hot-end and cold-end pressing jigs, each jig has a fulcrum with springs, and the force and relative positions of the fulcrums can be adjusted steplessly
• Round and flat heat pipe pressing modules
• Cold end and the hot end are suitable for 4, 5, 6, 8, 10mm diameter and flat heat pipe fixtures, 1 set each
• Cooling module is a water-cooled structure, providing water with constant temperature Tcw for cooling
• Cold end has a positioning module that can be moved and adjusted conveniently
• Contact area of the cold end and the hot end are both 30 × 30 mm
• Cooling water temperature range: From room temperature +5℃ to 50℃

Heat Pipe Response Rate Measurement Plateform:

• Constant-temperature water tank with automatic temperature control
• Temperature holding fixtures for long heat pipes (round and flat)
• Temperature holding fixture for short heat pipes (round and flat)
• Elevated rack for constant temperature water tank

Control System:

• The automatic mode is directly controlled by the PC to automatically start the test
• Digital data acquisition and transmission
• RS-232 communication interface
• Computer calculation control and automatic power adjustment

Use Environment:

• Operating temperature range: 4 ~ 40℃
• Indoor environment, avoid direct sunlight

Dimensions:

• Dimensions: 0.8 (W) × 1.2 (L) × 1.7 (H) M
• The power supply is AC 110V, single-phase, 15Amp

Steady–State Test and Curve

Step 1:

Place the test object between the heating end and the condensation end.

Step 2:

Input heat from a controllable heat source and remove the heat from the water cooling through the specimen.

Step 3:

Measure the heating end, the reference temperature of the condensing end and the temperature of other points (Tc1, Tc2, Thc, Thb) on the heat pipe.

Calculation Method

Thermal Resistance

The thermal resistance of the test object： Tc：Reference temperature of the condensing end
Th: Reference temperature of heating end
Q：Heat flux

Effective Thermal Conductivity

Equivalent thermal conductivity coefficient of the test object：

Q: Heat flux
A: Sectional Area of test object
ΔX: Distance from the heating end to the condensation end
ΔT: Difference between the reference temperature of the heating end and the reference temperature of the condensation end

Thermal Resistance of Heat Pipes Example

In this example, we used heat pipes with different diameters and lengths to compare the thermal resistance of each heat pipe.


Heat pipes with larger diameters transfer more heat than heat pipes with smaller diameters. Shorter length heat pipes can also transfer more heat than heat pipes with longer lengths.

Heat Pipe Power at Different Angles Example

Below are the results of a 6mm diameter and 200mm length heat pipe tested at different angles using the attitude adjustment device.

Thermal Response Rate Example

In this example, a heat pipe with a diameter of 6mm and a length of 200mm is used again. The thermostatic water is set to 65°C and the initial temperature of the heat pipe is approximately ~20°C. After about 7 seconds, the hot end temperature rises to about ~55°C and approaches steady state.


Tt: Water Temperature
Tc: Heat Pipe Temperature

Reserve Laboratory: