2018
Development and analysis of thermosyphon based on mini-channels operating with phase change
Concentration area:
Nature of the Project: Research
Starting Data:
Research line:
Project Status: In progress
Description:
The research project proposed as its main objective the development and evaluation of thermosyphons based on mini-channels operating with phase change. From the literature review, it can be seen that there is a reduced number of experimental investigations on heat transfer coefficient, pressure loss, flow patterns and mass flow during two-phase flows in thermosyphons based on mini-channels. However, there is the potential for applying this type of system for thermal control of various equipment such as power electronic devices, photovoltaic cells with solar concentrators, electrical machines and equipment. From the review presented the proposal, it is concluded that these dominant mechanisms of heat transfer and momentum during flows in thermosyphons with natural circulation are different from the mechanisms selected for forced convection conditions. Therefore, there is a lack of experimental studies to precisely determine interruptions in two-phase flow, which can contribute to a better understanding of the characteristics that occur during boiling and convective condensation in systems with natural circulation, as well as to the development of prediction methods. For the development of the experimental stage of this research project, the aim is to design and build an experimental apparatus with the objective of evaluating the heat transfer coefficient, flow patterns and mass flow rate for thermosyphons based on mini-channels operating with deionized water and ethanol. , in vertical channels with an internal diameter between 2.0 and 4.0 mm. The aim is to obtain experimental results for different conditions of heat flow, filling ratio, and saturation temperatures.
Team:
Students involved: Undergraduate: (1) / Specialization: (0) / Academic master’s degree: (1) / Professional master’s degree: (0) / Doctorate: (1) .
Members: Fabio Toshio Kanizawa – Coordinator / Gustavo Moreira dos Santos – Member / Rian Maurício Santana – Member / Jaqueline Diniz da Silva – Member.
Financiers: Carlos Chagas Filho Foundation for Research Support in the State of RJ – Financial assistance. Number of productions C, T and A: 3
Evaluation of thermo-hydraulic parameters during boiling and convective condensation inside channels with forced vibration
Concentration area:
Nature of the Project: Research
Start date:
Research line:
Project status: In progress
Description:
This research proposal refers to the request for resources to carry out a research project in accordance with Universal Call MCTIC / CNPq 28/2018, Range A. The proposed project’s main objective is the theoretical and experimental evaluation of thermal and hydraulic parameters during boiling and convective condensation in horizontal circular channels, of conventional and reduced dimensions, subjected to forced vibration. From the literature review, it can be seen that there is a reduced number of experimental investigations on active techniques for intensifying heat transfer coefficients during convective boiling and condensation. The imposition of vibrations in the channels is an active technique applied to intensify the heat transfer coefficient reported in the literature, however there is no experimental investigation for boiling conditions and convective convection with forced vibrations of the channels. Bearing in mind that fluid circulation in refrigeration systems is generally carried out through compressors, which eventually transmits vibrations to the system’s heat exchangers, this intensification mechanism is intrinsic to many systems.In the case of convective condensation inside horizontal channels, it is expected that the vibration of the channel favors the rupture or reduction in thickness of the liquid film along the wall, thus resulting in an increase in the heat transfer coefficient. For convective boiling inside channels subject to forced vibration, the rupture of liquid films along the wall can result in a reduction in the heat transfer coefficient or even in anticipation of wall drying. Therefore, the present research project aims to develop an apparatus for experimental evaluation of the heat transfer coefficient, pressure loss and flow patterns during boiling and convective condensation inside horizontal channels subject to forced vibration. The aim is to evaluate circular channels with internal diameters between 3 and 10 mm, flows of refrigerants R134a, R410A, R600a and R290, and saturation temperatures between -5 and 40 °C. Additionally, it is intended to use an electromechanical actuator to impose vibration frequencies between 20 and 60 Hz of up to 10 m/s², with the aim of covering the operating range of compressors driven by frequency inverters, with vertical and horizontal vibration modes. , axial and mixed..
Team:
Students involved: Undergraduate: (0) / Specialization: (0) / Academic master’s degree: (2) / Professional master’s degree: (0) / Doctorate: (0) .
Members: Fabio Toshio Kanizawa – Coordinator / Rian Maurício Santana – Member / Matheus Coitinho Constantino – Member.
Funders: National Council for Scientific and Technological Development – Financial assistance.
CNPq Grant 310328/2017-9: ?Modeling the cyclic inelastic behavior of polymeric materials?
Concentration area:
Nature of the Project: Research
Start date:
Research line:
Project status: In progress
Description:
Team:
Members: Heraldo Silva da Costa Mattos – Coordinator.
Funders:
PETROBRAS-UFF-FEC Agreement. Cooperation agreement 5850.0107860.18.9. ? Low-cost composition repairs?. 2018-2020.
Concentration area:
Nature of the Project: Research
Starting Data:
Research line:
Project Status: In progress
Description:
Team:
Members: Heraldo Silva da Costa Mattos – Coordinator.
Funders:
FAPERJ Project E-26/203.069/2017 – Grant in the Cientistas de Nosso Estado Program – ?Modeling the cyclic inelastic behavior of polymeric materials?
Concentration area:
Nature of the Project: Research
Start date:
Research line:
Project Status: In progress
Description:
Team:
Members: Heraldo Silva da Costa Mattos – Coordinator.
Funders:
FAPERJ Project E-03/2018 – Grant in the Scientists of Our State Program Characterization of Fatigue Behavior of Modified Polymeric Composites
Concentration area:
Nature of the Project: Research
Start date:
Research line:
Project Status: In progress
Description:
SCIENTIST OF OUR STATE – 2018.
Team:
Members: João Marciano Laredo dos Reis – Coordinator.
Funders: