Non-invasive, energy-autonomous and wireless temperature sensor for the process industy
Temperature sensors for application in the process industry are typically mounted in a thermowell. These tubular fittings penetrate the surface of e.g. a pipe and allow to insert a temperature sensing element into the process medium. Although this invasive sensing is state-of-the-art, thermowells suffer from significant drawbacks: Any pipe penetration is a potential cause for leakage and the thermowell itself is prone to corrosion, abrasion and bending stress. Avoiding the thermowell by measuring temperature on the surface of the process container was so far not considered a widespread alternative to invasive sensing. The temperature of the surface is generally not considered representative for the temperature of the process medium. A surface sensor is strongly exposed to the ambient condition and, furthermore, the calibration of such a surface sensor is challenging. In this paper we demonstrate how to overcome these limitations by an optimized thermo-mechanical design and enhanced model-based sensing. In combination with energy autonomous operation and wireless communication our novel non-invasive sensor offers a remarkable flexibility enabling scenarios discussed within the context of internet of things (IoT).
Accurate and quickly responsive surface temperature measurement: a step to widespread non-invasive T-measurement in industry
Non-invasive temperature sensing has the potential to considerably enhance the safety and simplicity of temperature measurement in industrial process facilities. By accurately and reliably measuring the outer wall temperature of a piping conveying a liquid, the needs for a traditional invasive device can be eliminated in many common process circumstances. However, surface sensors are not widely used largely due to two factors: ambiguity of the process conditions that allow for surface measurements and inaccuracies that arise from improper device design and installation. This paper outlines the key process conditions where surface measurements would suffice. It also subsequently presents a framework for modeling a surface measurement sensor with insights on how to improve the measurement accuracy. Experiments with a device that utilizes the derived insights are presented which demonstrate temperature measurement performance equivalent to traditional invasive sensors.
A New Vacuum Pressure Infiltration CFRP Method and Preparation Experimental Study of Composite
In order to prepare a carbon-fiber-reinforced polymer composite (CFRP) with ideal microstructure and properties, a new vacuum pressure infiltration CFRP method is proposed based on an analysis of existing CFRP preparation process methods. Research on composite material preparation systems was carried out by using this new method principle. The system mainly includes a fiber pre-forming module, a vacuum heating infiltration module, a hot-press curing molding module, and a data acquisition control module. Under the conditions of natural curing at 0 MPa + 6 h + 25 °C, vacuum heating curing at –0.05 MPa + 30 min + 80 °C, and hot-press curing at 0.7 MPa + 5 min + 50 °C, a two-dimensional (2D) CFRP with excellent microstructure and properties was successfully prepared. Observing the microstructure of the prepared composite material, it can be found that the inside of the composite material was sufficiently and uniformly infiltrated, and common preparation defects such as holes and delamination were effectively controlled. Through the performance test, the bending strength of the material reached 790 MPa.