Effect of Streamlined Fins on the Heat Transfer and Pressure Drop Characteristics in Printed Circuit Heat Exchangers for Super Critical Carbon dioxide Cycle

2019 ◽  
Author(s):  
Rajendra Prasad KS ◽  
Kamal Raj K ◽  
Jeevan Devagiri ◽  
Ganesh Pratheek KM ◽  
V. Krishna ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Carbon Dioxide ◽  
Pressure Drop ◽  
Heat Exchangers ◽  
Printed Circuit ◽  
Critical Carbon Dioxide

Heat Transfer of Supercritical Carbon Dioxide in Printed Circuit Heat Exchanger Geometries

2010 ◽  
Author(s):  
Alan Kruizenga ◽  
Mark Anderson ◽  
Roma Fatima ◽  
Michael Corradini ◽  
Aaron Towne ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Carbon Dioxide ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Supercritical Carbon Dioxide ◽  
Test Section ◽  
Heat Exchangers ◽  
Total Power ◽  
Printed Circuit ◽  
Supercritical Carbon

The increasing importance of improving efficiency and reducing capital costs has lead to significant work studying advanced Brayton cycles for high temperature energy conversion. Using compact, highly efficient, diffusion-bonded heat exchangers for the recuperators, has been a noteworthy improvement in the design of advanced carbon dioxide Brayton Cycles. These heat exchangers will operate near the pseudocritical point of carbon dioxide, making use of the drastic variation of the thermo-physical properties. This paper focuses on the experimental measurements of heat transfer under cooling conditions, as well as pressure drop characteristics within a prototypic printed circuit heat exchanger. Studies utilize type-316 stainless steel, nine channel, semi-circular test section, and supercritical carbon dioxide serves as the working fluid throughout all experiments. The test section channels have a hydraulic diameter of 1.16mm and a length of 0.5m. The mini-channels are fabricated using current chemical etching technology, emulating techniques used in current diffusion bonded printed circuit heat exchanger manufacturing. Local heat transfer values were determined using measured wall temperatures and heat fluxes over a large set of experimental parameters that varied system pressure, inlet temperature, and mass flux. Experimentally determined heat transfer coefficients and pressure drop data are compared to correlations and earlier data available in literature. Modeling predictions using the CFD package FLUENT are included to supplement experimental data. All nine channels were modeled using known inlet conditions and measured wall temperatures as boundary conditions. The FLUENT results show excellent agreement in total power removal for the near pseudocritical region, as well as regions where carbon dioxide is a high or low density fluid.

Heat Transfer of Supercritical Carbon Dioxide in Printed Circuit Heat Exchanger Geometries

2011 ◽  
Vol 3 (3) ◽  
Author(s):  
Alan Kruizenga ◽  
Mark Anderson ◽  
Roma Fatima ◽  
Michael Corradini ◽  
Aaron Towne ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Carbon Dioxide ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Supercritical Carbon Dioxide ◽  
Test Section ◽  
Heat Exchangers ◽  
Working Fluid ◽  
Printed Circuit ◽  
Supercritical Carbon

The increasing importance of improving efficiency and reducing capital costs has led to significant work studying advanced Brayton cycles for high temperature energy conversion. Using compact, highly efficient, diffusion-bonded heat exchangers for the recuperators has been a noteworthy improvement in the design of advanced carbon dioxide Brayton cycles. These heat exchangers will operate near the pseudocritical point of carbon dioxide, making use of the drastic variation of the thermophysical properties. This paper focuses on the experimental measurements of heat transfer under cooling conditions, as well as pressure drop characteristics within a prototypic printed circuit heat exchanger. Studies utilize type-316 stainless steel, nine channel, semi-circular test section, and supercritical carbon dioxide serves as the working fluid throughout all experiments. The test section channels have a hydraulic diameter of 1.16 mm and a length of 0.5 m. The mini-channels are fabricated using current chemical etching technology, emulating techniques used in current diffusion-bonded printed circuit heat exchanger manufacturing. Local heat transfer values were determined using measured wall temperatures and heat fluxes over a large set of experimental parameters that varied system pressure, inlet temperature, and mass flux. Experimentally determined heat transfer coefficients and pressure drop data are compared to correlations and earlier data available in literature. Modeling predictions using the computational fluid dynamics (CFD) package FLUENT are included to supplement experimental data. All nine channels were modeled using known inlet conditions and measured wall temperatures as boundary conditions. The CFD results show excellent agreement in total heat removal for the near pseudocritical region, as well as regions where carbon dioxide is a high or low density fluid.

scholarly journals Heat Transfer and Pressure Drop Characteristics in Straight Microchannel of Printed Circuit Heat Exchangers

Entropy ◽  
2015 ◽  
Vol 17 (5) ◽  
pp. 3438-3457 ◽  
Author(s):  
Jang-Won Seo ◽  
Yoon-Ho Kim ◽  
Dongseon Kim ◽  
Young-Don Choi ◽  
Kyu-Jung Lee
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Heat Exchangers ◽  
Printed Circuit

Heat Transfer Performance of Supercritical Carbon Dioxide in Microchannels

2015 ◽  
Author(s):  
Chien-Yuh Yang ◽  
Kun-Chieh Liao
Keyword(s):  
Heat Transfer ◽  
Carbon Dioxide ◽  
Pressure Drop ◽  
Critical Point ◽  
Test Section ◽  
Heat Transfer Performance ◽  
Transfer Performance ◽  
Test Results ◽  
Test Conditions ◽  
Critical Carbon Dioxide

This paper provides an experimental investigation of heat transfer performance and pressure drop of supercritical carbon dioxide cooling in microchannel heat exchanger. An extruded flat aluminum tube with 37 parallel channels and each channel of 0.5 mm × 0.5 mm cross section was used as the test section. Super critical carbon dioxide at pressure of 7.5 MPa and inlet temperature varied from 55 to 25 °C was tested. The temperature drops of CO2 cooled inside the test section was controlled at 2, 4 and 8 °C separately for each test to investigate the effect of properties change on the friction and heat transfer performance at various temperature cooling ranges near the critical point. The test results showed that while the test conditions were away from (approximately 5 °C higher or lower) the critical point, both heat transfer and pressure drop performance agreed very well with those predicted by convention correlations. However, while the test conditions near the critical point, the difference between the present test results and the prediction values is very high. From the experiment results of various temperature change range inside the test section, we can find that both heat transfer and pressure drop were strongly affected by the temperature cooling ranges near the critical point. Since there is a drastic peak of the properties change near the critical point, neither fluid properties at the average temperature nor the average properties at the inlet and exit temperatures may appropriately present the actual properties change in the test process. If we use the properties integrated but not averaged from inlet to the exit temperatures, we may obtain the results that agree well with the values predicted by conventional correlations. The heat transfer and pressure drop performance of super critical carbon dioxide are indeed similar to these at normal conditions if its properties were appropriately evaluated.

Investigation of Supercritical CO2 Thermal Hydraulic Characteristics in a Printed Circuit Heat Exchanger

2018 ◽  
Author(s):  
Wen Fu ◽  
Xizhen Ma ◽  
Peiyue Li ◽  
Minghui Zhang ◽  
Sheng Li
Keyword(s):  
Heat Transfer ◽  
High Temperature ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Heat Exchangers ◽  
Supercritical Co2 ◽  
Three Dimensional ◽  
Working Fluid ◽  
Printed Circuit ◽  
Carbon Dioxide Co2

Printed circuit heat exchangers are considered for use as the intermediate heat exchangers (IHXs) in high temperature gas-cooled reactors (HTGRs), molten salts reactors (MSRs) and other advanced reactors. A printed circuit heat exchanger (PCHE) is a highly integrated plate-type compact heat exchanger with high-temperature, high-pressure applications and high compactness. A PCHE is built based on the technology of chemical etching and diffusion bonding. A PCHE with supercritical carbon dioxide (CO2) as the working fluid was designed in this study based on the theory correlations. Three-dimensional numerical analysis was then conducted to investigate the heat transfer and pressure drop characteristics of supercritical CO2 in the designed printed circuit heat exchanger using commercial CFD code, FLUENT. The distributions of temperature and velocity through the channel were modeled. The influences of Reynolds number on heat transfer and pressure drop were analyzed. The numerical results agree well with the theory calculations.

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