What is the thermal resistance of Shenyang Xinyang explosion-proof heater? - Yangzhou Darui

What is the thermal resistance of Shenyang Xinyang explosion-proof heater? - Yangzhou Darui

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What is the thermal resistance of a cast aluminum heating tube?Cast aluminum heater The working fluid also affects the thermal resistance of the cast aluminum heater. First, the working fluid should be operated in a region where the saturation vapor pressure-temperature curve has a steep slope, so that under a certain vapor pressure drop, the vapor temperature difference is small, reducing the axial thermal resistance of the cast aluminum heater. The influence of the working fluid on the radial thermal resistance of the cast aluminum heater can be discussed in several cases.

For high-temperature liquid metal working fluid cast aluminum heaters, since the thermal conductivity of the working fluid and the metal wick are of the same order of magnitude, the equivalent thermal conductivity of the wick filled with working fluid is comparable to that of the metal. It can be seen that the working fluid has a certain influence on the radial thermal resistance, but not very large, and its radial thermal resistance is relatively low. For medium and low temperature cast aluminum heaters, many experimental data show that because the thermal conductivity of the working fluid itself is low, the temperature difference mainly depends on the wick structure and whether the liquid boils. Of course, for the same wick structure, a liquid with higher thermal conductivity has correspondingly lower thermal resistance, but there is no linear relationship between the two.

In a cast aluminum heater, whether the working fluid liquid boils has a significant impact on thermal resistance. Generally speaking, when the heat flux is high, the liquid in the evaporator wick will boil. For different wicks, the effect of boiling is different. For axial groove wicks, vapor bubbles generated by boiling can easily escape to the vapor space, so boiling does not affect the liquid flow in the wick, but instead enhances heat transfer.

However, for wicks with mesh on axial grooves or annular flow channel wicks, the vapor generated by boiling in the liquid channel is not easy to escape due to the obstruction of the liquid film on the fine mesh, thereby increasing the resistance to liquid flow and even causing local dryout in the evaporator section. These can cause unpredictable degradation in the performance of the cast aluminum heater. Therefore, for such wicks, it is necessary to choose a working fluid that is not prone to boiling.

Note: The above information and technical parameters are compiled and released by Yangzhou Darui Electric Co., Ltd.