Study of the Boiling Process in Electric Jet Boilers – Optimization of Equipment Durability Based on Experimental Data Analysis and Multiphysics CFD Process Modeling

Industrial systems are increasingly transitioning toward renewable energy in order to reduce carbon emissions and reliance on fossil fuels.[1] In this context, boilers remain major consumers of fossil fuels for heat generation, highlighting the need for efficient electrified alternatives.[2] Among these solutions, jet electrode boilers provide an efficient method for converting electrical energy into steam.[1] These boilers operate by discharging conductive water as high-velocity jets onto high-voltage electrodes to allow current to flow through the fluid and generate volumetric Joule heating. This mechanism leads to rapid steam production with high efficiency, making these systems well suited for grid balancing by using surplus electricity from intermittent renewable sources.[1] Despite their long-standing use, electrode jet boilers face durability and stability challenges under dynamic conditions.[1] Transient regimes during start-up and shutdown may lead to electric arc formation. This phenomenon results in localized high-intensity electric fields, accelerating electrode degradation.[1] Moreover, boiling may induce vapor priming and droplet entrainment, degrading steam purity.[3] Additional complexities arise from electrochemical reactions, resulting in the generation of hydrogen and oxygen gases.[1] The coupled interactions between fluid dynamics, heat transfer, phase change, and electromagnetic fields within the jet region remain poorly understood. This PhD project, conducted within a CIFRE collaboration between AIT Stein Energy Boilers and the LEMTA (Universite de Lorraine), aims to develop a comprehensive multiphysics framework to investigate these phenomena by investigating the boiling process within jet electrode boilers through a combined numerical and experimental approach. A computational fluid dynamics model will be developed to capture the coupled interactions within the jet region supported by experimental validation. Parametric studies will be conducted to evaluate the effects of water conductivity, current frequency, and nozzle geometry on system stability and performance. The main objectives are to reduce electrode wear, prevent arcing, improve steam quality, and enhance operational flexibility under dynamic conditions. The expected outcomes include improved understanding of vapor formation and electric-field interactions, and the development of optimized design concepts to enhance the durability and reliability of jet electrode boilers. References [1] Zhao, Z., Hu, R., Zhang, Y., Dong, H., & Du, Q. (2025). Current Research Status and Prospects of Electrode Boilers Under the Background of the "Dual Carbon" Goals. Energies, 18(4), 769. [2] Rissman, J. (2022). Decarbonizing low-temperature industrial heat in the U.S. Energy Innovation Policy and Technology LLC. [3] He, X., Ruan, Y., & Wang, W. (2024). Three-Dimensional Transient Electric Field Characteristics of High-Pressure Electrode Boilers. Electronics, 13(9), 1615.

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