Fouling Detection with Heat Flux Sensing Technology
This short review describes how heat flux sensing technologies can be employed to perform fouling detection for a broad range of research and industrial applications.
Introduction to Fouling Detection
Fouling is a process that occurs when an unwanted material that can consist of either living organisms or a non-living substance, accumulates and creates a layer on the solid surface where it is deposited (e.g. furring in a water pipe). This layer increases the absolute thermal resistance of the component.
The increase of the absolute thermal resistance can be measured by combining a heat flux sensor with two temperature sensors. Fouling occurs in various industrial or research environments.
How to perform Fouling Detection with Heat Flux Sensors
Absolute thermal resistance calculation
The absolute thermal resistance between the measurement points T1 and T2 are defined by the following:
Rth = ∆T / HF with
Rth = Absolute thermal resistance, in K/W
HF = Heat Flux, in W
∆T = Temperature difference, in K
Fig 1. and Fig 2. represents a standard structure for heat exchangers with and without fouling.
Fig 1. Absolute thermal resistance without fouling
Fig 2. Absolute thermal resistance with fouling
It is observed that as soon as fouling occurs and a layer of material (bacterial film for instance) deposes on the heat exchanger fins, the Absolute Thermal Resistance Rth increases.
When the temperature gradient, ∆T and the Heat flux, HF are measured, this change in Absolute thermal resistance can be evaluated, and fouling, detected.
This detection process can be applied for many fields of application because fouling can occur in many processes.
Other interesting deposition examples are ice formation (e.g. on plane wings), and algae formation (e.g. on ship hulls) or even bacterial formation in medical devices/tubings.
Advantages of using gSKIN® Heat Flux Sensor for Fouling detection
gSKIN® Heat Flux Sensor is suited to performed fouling detection:
- Miniature & compact heat flux sensor
- Highly sensitive sensor
- Facilitated integration into the application setups
- Non-invasive measurement technique for determining fouling
- Flexible, easy to mount on pipes and boilers
More R&D Uses Cases where the gSKIN® Heat Flux Sensor is employed are available here.