IMPRESS-U Call Partner Search Tool

General Information

• Type: Partner looking for project
• Organisation: Koszalin University of Technology, Faculty of Mechanical and Energy Engineering, Department of Power Engineering
• Country: Polska (PL)

Research area

• NSF calls:
  • EAGER
  • International Supplements
• Keywords:

  Phase transformations of eco-friendly refrigerants compact heat exchangers built with mini-channels 3D printing of metal powders

• Brief description of your expertise / expertise you are looking for:

  Objective of the research The assumed purpose of the research is to perform an analysis of the condensation process of new pro-environmental refrigerants in compact heat exchangers manufactured by 3D printing from metal powders. For this purpose, it is planned to conduct experimental tests on a group of new refrigerants with sufficiently low parameters: ODP (Ozone Depletion Potential), related to Freon R11, for which ODP = 1 is assumed, and GWP (Global Warming Potential), related to CO2, for which GWP = 1 is assumed. These are intended to be replacements for a group of mixtures R507, R407C, R407F, R419A, R422D, R448A R449A, R452A, R455A used, as replacements for R404A.

• Brief description of your project / the project you would like to join:

  Research methodology used Within the framework of the project, it is planned to use experiment, as a basic research tool, as an authoritative criterion for evaluating the correctness of analytical solutions. The experiment creates conditions for learning about new flow phenomena that accompany the phase transformation of liquefaction. The research will be carried out under laboratory conditions. Accordingly, it is planned in the descriptive range: • recognition and qualitative and quantitative description of the phenomena accompanying the liquefaction of substitutes for end-of-life refrigerants in compact heat exchangers • theoretical and experimental analysis of these phenomena, in order to expand the current state of knowledge in this area, • analysis of the applicability of existing computational methods to the condensation in mini-channels of new environmentally friendly refrigerants, • proposals for modification of the computational methods used so far in describing the phenomena accompanying the process of condensation of refrigerants in compact heat exchangers. In the practical field, it is planned to make compact heat exchangers by 3D printing from metal powders such as 316L steel and Cu. First of all, designs of heat exchangers with circular and rectangular channels with a hydraulic diameter of 1 mm will be made. The assumed external dimensions and the number of channels present will be determined by the working field of the printers. Currently, such devices are available at the Rapid Prototyping Center of the Mechanical Faculty of the Koszalin University of Technology and the Mechanical Faculty of the Opole University of Technology. The compact heat exchangers will be made using Selective Laser Melting (SLM) technology. The SLM process makes it possible to produce a component with features that cannot be achieved by conventional manufacturing techniques. It will allow the use of a design that enables the implementation of the refrigerant liquefaction process as a result of heat extraction by water, the temperature of which will be stabilized by means of heating-cooling baths. An important element in the condensation process in mini-channels is the capillary interaction caused by small spaces and the inner surface (roughness) of the channels. Under certain conditions, these properties can cause the initiation of the phase transformation process or have an adverse effect, causing, for example, blockage of flow in areas of single-phase subcooled liquid. In the literature, such a phenomenon is described as Cappilary Blocking. Thanks to the cooperation with the Opole University of Technology and Germany, research will be carried out on the quality of the compact heat exchanger prints made, the permeability and the degree of roughness of the internal surfaces of the channels. The impact of the expected results on the development of science, civilization, society The main role in the issues of operation of machinery and power equipment is played by two aspects, which are: rational use of energy and environmental protection. Current development trends for these systems strive for their miniaturization. The design of compact heat exchangers capable of transferring significant values of heat flux density is part of this issue. The design of these exchangers is based on micro- and mini-channels, which form multiports. Learning about the mechanism of the liquefaction process in compact heat exchangers fabricated by 3D printing from metal powders, the proposed F-gas replacements, will make it possible to assess the feasibility of such processes in such structures. This will result in the need to formulate modifications or new relationships for the characteristic quantities describing this phenomenon.

Waldemar Kuczyński

• Organisation: Koszalin University of Technology, Faculty of Mechanical and Energy Engineering, Department of Power Engineering
• Position: Profesor/Dean of the Faculty of Mechanical and Energy Engineering
• E-mail: waldemar.kuczynski@tu.koszalin.pl
• Phone: 48 943478437
• Web: tu.koszalin.pl/wm/kat/544/pracownicy