Razvoj naprednih numeričnih modelov pretočnih komor za obdelavo s pulzirajočim električnim poljem

Lombergar, Peter (author), Miklavčič, Damijan (mentor), Mahnič-Kalamiza, Samo (comentor)

Obdelava s pulzirajočim električnim poljem (angl. PEF treatment) je obetavna tehnologija na področju prehranske industrije, biotehnologije in okoljevarstva, ki temelji na dovajanju kratkih, visokonapetostnih pulzov. Ena glavnih komponent sistema za obdelavo s pulzirajočimi polji je pretočna komora, saj je v njej obdelovanec izpostavljen električnim pulzom. Numerični modeli pretočnih komor nam omogočajo edinstven vpogled v porazdelitev električnega polja, pretok obdelovanca in temperaturo znotraj komore, ki eksperimentalno ni mogoč. Obstoječa literatura opisuje le stacionarne simulacije, ki ne zajemajo vpliva posameznih električnih pulzov, temveč operirajo s časovnim povprečenjem napetosti na elektrodi. Namen magistrske naloge je bil zgraditi časovno-odvisni numerični model pretočne komore za obdelavo s pulzirajočim električnim poljem in njegovo pravilnost preveriti s poskusi. Glavni poudarek pri izgradnji modela je bila zmožnost upoštevanja vsakega električnega pulza posebej. V poskusih in simulacijah so bile uporabljene tri pretočne komore različnih oblik in dimenzij (manjša in večja linearna komora ter obročna komora) ter različni parametri električnih pulzov in vrednosti volumskih pretokov za vodno raztopino NaCl. V numeričnem modelu je bila zgrajena geometrija komor v treh dimenzijah in zajeto dovajanje električnih pulzov, pretok tekočine, segrevanje zaradi ohmskega gretja in prenos toplote. Model je bil validiran s primerjavo vrednosti pridobljenimi z numeričnimi simulacijami z eksperimentalno izmerjenimi vrednostmi električnega toka in spremembe temperature tekočine v iztoku pretočnih komor med dovajanjem električnih pulzov. Z uporabo numeričnega modela je bila za vsako pretočno komoro narejena analiza in primerjava profilov električnega polja in temperature tekočine v komorah. Na koncu je prikazana še uporaba modela za simulacije obdelave s PEF pri različnih parametrih, ki zaradi omejitev eksperimentalne opreme niso bili izvedljivi.

• Language: Slovenian
• Keywords: obdelava s pulzirajočim električnim poljem, pretočna komora, numerično modeliranje, elektroporacija
• Work type: Master's thesis/paper
• Organization: FE - Faculty of Electrical Engineering
• Year: 2020
• PID: 20.500.12556/RUL-120064
• Publication date in RUL: 15.09.2020

LOMBERGAR, Peter, 2020, Razvoj naprednih numeričnih modelov pretočnih komor za obdelavo s pulzirajočim električnim poljem [online]. Master’s thesis. [Accessed 6 July 2025]. Retrieved from: https://repozitorij.uni-lj.si/IzpisGradiva.php?lang=eng&id=120064

Secondary language

• Language: English
• Title: Development of advanced numerical models of continuous flow chambers for pulsed electric field treatment

Abstract

Pulsed electric field (PEF) treatment is a promising novel technique in the field of food processing industry, biotechnology, and environmental engineering. It is based on applying short, high-intensity electric pulses. One of the main components of a PEF treatment system is a treatment chamber, in which the product is exposed to electric pulses. Numerical modeling provides a unique insight into the distribution of the electric field, fluid flow, and temperature inside the treatment chamber, which cannot be provided experimentally. Existing literature is reporting only on stationary state simulations that do not account for the influence of individual electric pulses, but rather employ a time-averaging of the voltage applied to electrodes. The purpose of the thesis was to build a time-dependent numerical model of a continuous PEF treatment chamber and to validate the model by experiments. The main focus in building the model was to account for the influence of each individual electric pulse. In the experiments and simulations, three different treatment chambers (smaller and larger parallel plate chamber and co-linear chamber) and different pulse parameters with different values of the volumetric flow of aqueous NaCl solution were used. In the numerical model, the geometry of treatment chambers was constructed in three dimensions, and the applications of electrical pulses, fluid flow, heating of fluid due to ohmic heating, and heat transfer were described. The model was validated by comparing the values obtained by numerical simulations with the experimentally measured electric current and changes in temperature of the fluid within the outlet of treatment chambers during pulse application. Using the numerical model, an analysis and comparison of the electric field and temperature profiles was made for each treatment chamber. Finally, the model was used to study the effect of different PEF treatment parameters within ranges that could not be performed due to the limitations of the experimental equipment.

• Keywords: pulsed electric field treatment, treatment chamber, numerical modeling, electroporation