Fouling Detection in an Optically Accessible Microstructured Heat Exchanger

Abstract

The application of highly effective microstructured devices in continuous production and industrial environments is frequently prone to fouling. A new method is presented to characterize fouling in these microstructures. Thermal fouling of aqueous solutions containing whey protein were used as a test system. Different fouling effects could be observed and distinguished. Integral fouling indicators, such as thermal fouling resistance and pressure drop, as conventional criteria for the occurrence of fouling were compared with direct local optical observation. Low thermal fouling resistances could be detected.

Numerical and Experimental Investigation of Flow Maldistribution due to Blockage in Microstructured Heat Exchanger

“…To validate the computational modelling and the results obtained from CFD simulations, several experiments were conducted first to receive data for different scenarios. The experimental setup is an improved iteration of the experimental setup described in detail in [7]. Figure 1 Figure 2 shows an explosion draft of the used microstructured heat exchanger.…”

“…To realize different scenarios the actual number of free channels was varied, according to Figure 3, by blocking selected channels on purpose with silicone rubber mastic. To exclude flow cross contamination, as described in previous publications [7], and to ensure a complete blockage of the chosen microchannels, a blue color tracer was set before each experiment. Figure 4 demonstrates an example of the optical inspection before and after the application of the color tracer for experimental case 0, showing no cross flow between adjacent microchannels.…”

“…Since fouling will change the original geometry of the flow path during operation, it is not sufficient to optimize the flow distributors for clean cases, as has been done before [4 -6]. Therefore, the investigation of possible flow maldistribution due to partial or complete blockage of single flow paths is mandatory to understand and predict the fluid dynamic and thermal behavior of microstructured heat exchangers [7].…”

CFD Simulation of Flow Maldistribution due to Blockage in Microstructured Heat Exchanger

“…Modern technologies intend to use micro-scaled systems in a wide variety of chemical, biological and heat exchange applications to increase reliability and enhance process and heat transfer efficiency [1]. However, on the downside they can suffer from continuous fouling processes or complete blockage of single flow paths [2,3]. Such perturbations inside the fluid domain have a significant impact on flow distribution and continuous mass flow rate in microstructure geometry which is essential for heat exchangers performance [4].…”

Application of Machine Learning in Industrial Boilers: Fault Detection, Diagnosis, and Prognosis

“…Conversely, maintenance cost could make up to 15-70 % of total boiler heat production cost and likely to increase with the rising price of labour and materials [13,14]. Besides, the fuel property is another important factor to determine the maintenance duration as low-quality fuels may have severe the ash-related issues such as slagging and fouling [15][16][17]. These encourage the extension of regular maintenance duration by the boiler users provided that the boiler is functioning normally.…”