Non-invasive Temperature Measurement By Dr. Guruprasad Sosale

Summary

The speaker introduces a non-invasive temperature sensor technology that could potentially replace traditional thermal wells in industrial processes. By turning the pipe itself into a sensor, this approach promises increased safety, reduced installation time, and lower costs. The presentation delves into the physics behind the technology, demonstrating through models and experiments that under turbulent flow conditions, there's minimal temperature difference between the process medium and the pipe surface. The innovation is positioned as a game-changer for process engineers, offering a simpler, more cost-effective, and safer method for temperature measurement.

Takeaways

• 🌡️ The presentation introduces a non-invasive temperature sensor that aims to eliminate the need for thermal wells in industrial processes.
• 🔧 It proposes a paradigm shift where the pipe itself acts as the sensor, removing the need for invasive temperature measurements.
• 🔄 The non-invasive method simplifies temperature measurement by avoiding the need for different size thermo wells and reducing installation and engineering time.
• 🛠️ Traditional temperature measurements in the industry often involve thermo wells, which, despite being accurate and replaceable, have drawbacks such as erosion, corrosion, and potential for measurement errors.
• 🔬 An alternative to thermo wells is skin temperature sensing or surface sensors, which, while safer, are often considered inaccurate and slow, and are sensitive to ambient conditions.
• 📚 The speaker references a journal publication to underline the physics behind the non-invasive temperature measurement approach.
• 🔍 The physics model suggests that under certain conditions (turbulent liquid-like medium in a metal pipe), there is virtually no temperature difference between the medium and the surface, allowing for accurate surface measurements.
• 🛑 The developed model-based non-invasive temperature sensor uses two RTD sensors to compensate for errors associated with surface temperature sensors, providing an accurate and dynamic measurement.
• 📉 The non-invasive approach can match or outperform traditional thermal well performance, as demonstrated in a dynamic step response test in a research facility.
• 💡 The potential benefits of non-invasive sensors include safety, lower cost of ownership, and simplification of temperature measurement processes.
• 🌐 The non-invasive principle is scalable and can be applied to pipes ranging from DN40 to DN2500, offering a versatile solution for various industrial applications.

Q & A

What is the main topic of the speaker's presentation?

The main topic of the presentation is the introduction and explanation of a non-invasive temperature sensor technology that could potentially eliminate the need for thermal wells in process industry applications.

What is a thermal well, and why is it currently used?

A thermal well is a protruding unit inserted into a process flow to house a temperature sensor, such as an RTD or thermometer. It is currently used because it allows for accurate temperature measurements within the process fluid and is easily replaceable.

What are the drawbacks of using thermal wells?

The drawbacks of using thermal wells include the need for engineering to ensure they can withstand process conditions, potential for erosion, wear, and corrosion, and the inability to detect issues without inspections, which can lead to catastrophic damage if not addressed.

What is the concept of non-invasive sensing as discussed in the presentation?

Non-invasive sensing, in this context, refers to the idea of using the pipe itself as a sensor by measuring the surface temperature of the pipe without the need for inserting a thermal well into the process fluid.

Why might skin temperature sensors, another form of non-invasive measurement, be inaccurate or slow?

Skin temperature sensors might be inaccurate or slow because they measure the wall temperature of the pipe, which can be influenced by ambient conditions, and they may not respond quickly to changes in the process medium due to thermal resistance and other factors.

What is the theoretical basis for the claim that surface measurements can be as accurate as invasive measurements?

The theoretical basis is rooted in heat transfer principles, where if the insulation resistance is significantly higher than the combined resistance of the boundary layer and the wall, the temperature difference between the medium and the surface can approach zero, suggesting that surface temperature can accurately represent the process temperature.

What is the significance of the model-based non-invasive temperature sensor developed by the speaker's team?

The model-based non-invasive temperature sensor is significant because it uses a two-step approach involving a process model to predict medium temperature from surface temperature and a sensor that can accurately and dynamically measure the surface temperature of the pipe, compensating for common errors associated with surface temperature sensors.

How does the non-invasive temperature sensor overcome the limitations of traditional skin temperature sensors?

The non-invasive temperature sensor overcomes the limitations by using a thermal model of the entire sensor, which allows for compensation of common errors such as those caused by ambient conditions, and by measuring temperature at two different points close together to capture the dynamics of the pipe's temperature changes.

What are the potential benefits of adopting non-invasive temperature sensing in the process industry?

The potential benefits include increased safety by eliminating the need for drilling holes in pipes, reduced engineering and installation time, lower stocking requirements, and the simplification of temperature measurement processes.

How does the non-invasive approach compare to traditional thermal well measurements in terms of performance?

The non-invasive approach can match or even outperform traditional thermal well measurements by accurately predicting the medium temperature based on surface temperature measurements and using a sensor that captures the dynamics of the pipe's temperature changes.

What is the range of pipe diameters for which the non-invasive temperature sensor is applicable?

The non-invasive temperature sensor is applicable to a wide range of pipe diameters, from DN40 up to DN2500, allowing for its use in both small and large diameter piping across various process industry applications.