Investigation of convective boiling of quasi-critical fluids focusing on its application on organic Rankine cycles

• Grant number: 19/22105-5
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date until: April 01, 2020
• End date until: November 21, 2024
• Field of knowledge: Engineering - Mechanical Engineering - Thermal Engineering
• Principal Investigator: Gherhardt Ribatski
• Grantee: Daniel Borba Marchetto
• Host Institution: Escola de Engenharia de São Carlos (EESC). Universidade de São Paulo (USP). São Carlos , SP, Brazil
• Associated research grant: 16/09509-1 - Phase change heat transfer processes of high performance applied to solar energy recovery, AP.TEM
• Associated scholarship(s): 20/06705-0 - Experimental evaluation of the high-pressure flow boiling heat transfer of R245fa and R1233zd(E) in a microchannel, BE.EP.DR

Abstract

The Organic Rankine Cycle has potential of application in systems involving heat rejection remaining from processes and also in solar energy harvesting. As well as in heat pumps, in certain applications, the Organic Rankine Cycle may be subjected to evaporation pressures near the thermodynamic critical point. However, despite the growing interest in such applications, studies involving pressure drop and heat transfer under convective boiling conditions inside ducts are generally based on results for reduced saturation pressures and temperatures typical of refrigeration applications and most recently of electronic components cooling. Near the critical point, thermodynamic and transport properties present different values and behaviors from those observed at lower pressures, which drastically affects the thermohydraulic behavior of the fluid during evaporation. On contrary to supercritical fluids for which a considerable number of papers is available, it is noticed in literature that there is a shortage of experimental studies involving the convective boiling at near-critical pressures inside minichannels, and most studies used water or carbon dioxide as working fluids. In this context, the present proposal deals with the experimental survey of an extensive database for flow patterns, pressure drop, heat transfer coefficient and critical heat flux involving convective boiling and single-phase flow of R245fa and HFOs R1336mzz (Z) and R1233ze in small diameter channels and different flow inclinations. Based on these results, the thermohydraulic performance of convective boiling and single-phase flow near the critical point will be parametrically analyzed. In addition, pressure drop, heat transfer coefficient and critical heat flux prediction methods from literature will be evaluated for these experimental conditions and, if necessary, new methods will be developed to be used as design and optimization tools. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

MARCHETTO, D. B.; MOREIRA, D. C.; REVELLIN, R.; RIBATSKI, G.. A state-of-the-art review on flow boiling at high re duce d pressures. INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER, v. 193, p. 27-pg., 2022-09-01. (19/22105-5, 15/24834-3)

MARCHETTO, DANIEL BORBA; RIBATSKI, GHERHARDT. An experimental study on flow boiling heat transfer of HFO1336mzz(Z) in microchannels-based polymeric heat sinks. APPLIED THERMAL ENGINEERING, v. 180, p. 14-pg., 2020-11-05. (19/22105-5)