A multi-point film thermocouple structure for fluid dynamic temperature measurement

Abstract

The invention relates to a thin-film thermocouple temperature measurement sensor structure for fluid dynamic temperature measurement, which is composed of several single-point thin-film thermocouples evenly distributed in the circumferential direction, and each thin-film thermocouple is composed of thermocouple wires and wires embedded in a columnar main structure. The composition of the coating layer exposed on the surface of the main structure. Each single-point thermocouple has exactly the same structure and material, but the thickness of the coating layer is different. The multi-point thin-film thermocouple of the present invention can be used to measure the dynamic temperature of the fluid, and multiple different measured values ​​can be obtained due to the different response speeds of each point. The compensation algorithm matched with the multi-point thin-film thermocouple can save a lot of numerical calculation and calibration experiments, and effectively improve the measurement accuracy of dynamic temperature.

Description

technical field [0001] The invention relates to a multi-point thin-film thermocouple structure, which can be used for dynamic temperature measurement of a fluid, and can improve the measurement accuracy of the dynamic temperature of the fluid with a matching compensation algorithm. Background technique [0002] Thermocouple is one of the most widely used temperature sensors, which has the advantages of low cost and wide application range. However, due to the thermal inertia of the thermocouple sensing part, it is impossible to accurately measure the dynamically changing temperature, and it can only be used for steady-state temperature measurement: the thermocouple sensing part is the node of two thermocouple wires. When measuring temperature, the measured object (or Fluid) continuously heats (or cools) the thermocouple node, when the two reach thermal equilibrium, the temperature measured by the thermocouple is the temperature of the measured object (or fluid). In actual us...

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Problems solved by technology

[0004] However, the above methods have their own disadvantages: 1. The thin-wire thermocouple has a fragile structure and is very easy to damage, and the heat transfer area decreases with the reduction of the diameter of the wire, so the response speed of the thin-wire thermocouple is also limited.

2. Thin-film thermocouples have low heat capacity and fast response, but due to the large contact surface between the film and the substrate, even if the substrate with low thermal conductivity is used, the heat conduction is still very fast, which will cause the measured temperature to be different from the measured temperature. There is an error in the measured fluid temperature, which needs to be corrected

3. Due to changes in the flow conditions of the measured fluid, a large number of theoretical calculations and calibration experiments are required to establish a universal compensation relationship, which will greatly increase the cost

[0005] In summary, there is still a lack of thermocouples with fast response, high precision and low cost in the prior art that can be used to measure the dynamic temperature of fluids

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