Direct contact condensation intensification by droplet forming during breakup of liquid jet in a gaseous medium

• Applicant: Privatdozent Dr. Mathias Joachim Krause
• Subject Area: Mechanical Process Engineering
• Term: since 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 544939191

The use of sprayed liquids in combination with heat exchange processes, particularly phase change processes, is used in many critical technologies, especially in the energy industry. Such technologies are found, e.g., in steam power plants, where cold water is injected into hot steam to lower the temperature of the steam supplied to the turbine, as well as in contact condensers, where cold contact of wet or superheated steam allows it to condense and form a condensate. The scientific goal of the project is to thoroughly understand the liquid stream's breakup process during outflow from a subcritical nozzle and assess the impact of the stream parameters on the process of heat exchange with the gaseous medium. A particular focus is placed on water vapor condensation in direct contact (Direct Contact Condensation - DCC) with the drop surface. Specifically, the physically complex spray formation from the inlet jet (liquid jet breakup) will be researched, thanks to sophisticated non-contact experiments using optical methods, as well as thermodynamically consistent multi-phase fluid flow simulations based on novel mathematical modeling approaches and resulting efficient numerical schemes (such as Lattice Boltzmann Methods) implemented in the open source code OpenLB. Thus, we provide the simultaneous mapping of mechanisms in liquid stream formation and the processes of liquid spraying, drop formation, and condensation. The correct understanding of these mechanisms, depending on the geometric parameters of the outlet nozzle and boundary conditions, will enable the analysis of the stream properties impact on the heat transfer efficiency and phase change. In consequence, the project will push forward the large-scale usability and technology outsourcing of DCC systems in energy industry applications and beyond.

• DFG Programme: Research Grants
• International Connection: Poland
• Cooperation Partner: Professor Dr. Pawel Madejski