Teaching experimental device for measuring convective heat-transfer coefficient of micro-pipe

Abstract

The invention discloses a teaching experimental device for measuring a convective heat-transfer coefficient of a micro-pipe. The teaching experimental device comprises a vacuum adiabatic chamber, a power-adjustable heating unit, a data acquisition card and a computer which are connected with one another. An insulation sealing connection panel is connected with a stainless steel outer cavity through a bolt; a connection terminal is fixed to the insulation sealing connection panel; one side of a metal two-way joint is connected with a micron-sized metal pipe and fixed by a fluoro-rubber washer mounted in the metal two-way joint; the other side of the metal two-way joint is connected with a mixing chamber; one end of a fluid inlet / outlet pipeline is connected with the mixing chamber, while the other end is connected with the insulation sealing connection panel through a fastener; a platinum (PT) 100 temperature measurement probe is mounted at the upper end of the mixing chamber; a pressure sensor is mounted at the lower end of the mixing chamber; and a 50-mu m thermoelectric coupler is connected to an outer wall of the micron-sized metal pipe. For the use of a teaching experiment, the device provided by the invention has the advantages of low cost, simple operation, high stability and the like; operation and data acquisition processing are accomplished; and remote teaching can berealized.

Description

technical field [0001] The invention relates to the field of measuring convective heat transfer coefficients, in particular to a teaching experiment device for measuring microtube convective heat transfer coefficients. Background technique [0002] In the chemical industry, many processes and unit operations require heat transfer, and convective heat transfer is the most common application, which is the basis of heat transfer calculation in chemical industry and an important way to explore the enhancement or weakening of heat transfer. Convective heat transfer in engineering is the heat transfer process of convection and conduction that occurs when the fluid flows through the solid surface. The convective heat transfer coefficient reflects the heat exchange capacity between the fluid and the solid surface. When the temperature difference between them is 1K, the heat that can be transferred per unit wall area per unit time, the unit is W / (m 2 K). For students majoring in ch...

AI Technical Summary

Problems solved by technology

However, because the size of metal micropipes is usually only on the order of 100 microns, and the experiment needs to be carried out under adiabatic conditions, there are many difficulties in the measurement of fluid temperature and the connection of pipeline lines. method, but the operation is complicated when replacing the test pipeline, and methods of measuring temperature such as infrared detection and thermal liquid crystal have also been proposed, but the requirements for equipment are relatively high, and the investment is also large.

[0004] So far, the convective heat transfer coefficient measurement equipment used in the laboratory is mainly aimed at conventional pipe diameters (inner diameter greater than 1mm), for teaching and experimental purposes, simple operation, low cost, and high stability experiments for measuring convective heat transfer coefficients at the micro scale device not yet reported

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