Development of 1 MWe Supercritical CO2 Test Loop

Recent studies have demonstrated that sCO2 in a closed-loop recompression. Brayton cycle offers equivalent or higher cycle efficiency when compared with supercritical- or superheated-steam cycles at temperatures relevant for CSP applications. With funding under the SunShot initiative, the authors are developing a high-efficiency sCO2 turbo-expander for the solar power plant duty cycle profile and novel compact heat exchangers for the sCO2 Brayton cycle. However, no test loop exists to test the turbine and heat exchangers under development. Therefore, a customized test loop is being developed at Southwest Research Institute that will accommodate the full test pressures (80 to 280 bar) and temperatures (45 to 700°C) of the proposed Brayton cycle. The paper describes the design methodology to predict the pipe flow behavior and thermal growths as well as material selection. A customized natural gas fired heater is currently being designed, since no heater like it is available currently.

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A process for the dimensioning of the high efficiency plate fins of compact heat exchangers

International Journal of Heat and Mass Transfer ◽

10.1016/0017-9310(67)90137-8 ◽

1967 ◽

Vol 10 (6) ◽

pp. 771-781 ◽

Cited By ~ 2

Author(s):

L. Szücs ◽

C.S. Tasnádi

Keyword(s):

Heat Exchangers ◽

High Efficiency ◽

Compact Heat Exchangers

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Effect of High Coolant Velocity on Heat Transfer in Compact Heat Exchangers

Heat Transfer, Volume 1 ◽

10.1115/imece2006-14042 ◽

2006 ◽

Author(s):

P. L. Sathyanarayanan ◽

N. Venkateswaran ◽

R. Ramprabhu

Keyword(s):

Heat Transfer ◽

Heat Exchangers ◽

High Efficiency ◽

Fluid Velocity ◽

Small Diameter ◽

Space Applications ◽

Compact Heat Exchangers ◽

Military Vehicle ◽

Transfer Capability ◽

Lower Fluid

Compact Heat Exchangers were developed to have very high efficiency in transfer of heat within a very small space or volume and are being used in the automotive, aircraft and space applications. In order to obtain much higher heat transfer, these Heat Exchangers uses closely packed fins, narrow or small diameter passages and turbulators or turbulence promoters. Though these arrangements result in much higher pressure drop for the fluids, this disadvantage is expected to be off-set with a larger increase in heat transfer capability. Generally it is known that turbulence enables better mixing of the fluid and results in enhancing the heat being transferred. However in practice it has been observed that there is a limit to this enhancement and the heat transfer does not improve beyond certain turbulence levels. The higher turbulence level probably results in carrying the heat away along with the fluid without transferring all the heat to the cooling medium. The presence of turbulence promoters was found to be beneficial at a lower fluid velocity level, where they conduct the heat away more by surface conduction than by convection in the fluid. Detailed experimental investigation and findings of this phenomenon using a compact heat exchanger for a military vehicle is described in this paper.

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Development of a High-Efficiency Hot Gas Turbo-expander and Low-Cost Heat Exchangers for Optimized CSP Supercritical CO2 Operation

10.2172/1560368 ◽

2019 ◽

Author(s):

Jeff Moore ◽

Keyword(s):

Heat Exchangers ◽

Supercritical Co2 ◽

High Efficiency ◽

Low Cost ◽

Hot Gas ◽

Turbo Expander

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Fluid Dynamic Simulation and Optimization of Compact Heat Exchangers with Louver Fins

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.798.205 ◽

2015 ◽

Vol 798 ◽

pp. 205-209

Author(s):

Diego Amorim Caetano de Souza ◽

Lúben Cabezas Gómez ◽

José Antônio da Silva

Keyword(s):

Heat Exchangers ◽

Energy Use ◽

Fluid Dynamic ◽

Flow Behavior ◽

Mechanical Energy ◽

The Body ◽

Compact Heat Exchangers ◽

Simulation And Optimization ◽

Wide Range ◽

Computational Fluid Dynamics Cfd

Every technological process developed since the beginning of humanity to the present day always involves some kind of energy use, either mechanical energy of the body or energy from burning fuel or the solar energy obtained from the sun. To manipulate and use that energy, the man always developed resources and equipment to allow it. Among the wide range of equipment, heat exchangers, designed to transfer heat from one fluid to another, will be analyzed in this work. To do this analysis, are used computational fluid dynamics (CFD) techniques to analyze the flow behavior of a compact heat exchanger, of tube and louvered fins type. After this step that aims to pull the parameters of efficiency, optimization features will be used to be able to propose a model for more efficient fin.

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Lead-to-CO2 Heat Exchangers for Coupling of the STAR-LM LFR to a Supercritical Carbon Dioxide Brayton Cycle Power Converter

12th International Conference on Nuclear Engineering, Volume 1 ◽

10.1115/icone12-49303 ◽

2004 ◽

Author(s):

Anton V. Moisseytsev ◽

James J. Sienicki ◽

David C. Wade

Keyword(s):

Carbon Dioxide ◽

Heat Exchanger ◽

Supercritical Carbon Dioxide ◽

Heat Exchangers ◽

High Efficiency ◽

Natural Circulation ◽

Power Converter ◽

Working Fluid ◽

Brayton Cycle ◽

Supercritical Carbon

Recent development of the Secure Transportable Autonomous Reactor-Liquid Metal (STAR-LM) lead-cooled natural circulation fast reactor (LFR) has been directed at coupling to an advanced power conversion system that utilizes a gas turbine Brayton cycle with supercritical carbon dioxide (S-CO2) as the working fluid. A key ingredient in achieving a coupled plant having a high efficiency are the modular lead-to-CO2 heat exchangers that must fit within the available volume inside the reactor vessel and must heat the S-CO2 to a high temperature. Thermal hydraulic performance and feasibility of seven different heat exchanger concepts has been investigated with respect to the achievement of a suitably high Brayton cycle efficiency for the coupled LFR-S-CO2 plant. The relative merits of the different heat exchanger configurations are revealed by the analysis which provides a basis to select the most promising concepts for further development.

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Modeling and Analyzing of Simple Combined Cycle of Modular High Temperature Gas Cooled Reactor

Volume 5: Student Paper Competition ◽

10.1115/icone24-60576 ◽

2016 ◽

Author(s):

Xinhe Qu ◽

Xiaoyong Yang ◽

Jie Wang

Keyword(s):

High Temperature ◽

High Efficiency ◽

Rankine Cycle ◽

Combined Cycle ◽

Inlet Temperature ◽

Outlet Temperature ◽

Brayton Cycle ◽

Reactor Outlet ◽

Cycle Efficiency ◽

High Temperature Gas

High temperature gas cooled reactor (HTGR) which is one of generation IV reactor has been widely given attention in many countries since the sixties of the last century because of its inherent safety and high efficiency. Currently, the HTGR commonly uses regenerative Brayton cycle. However, as reactor outlet temperature (ROT) rising, regenerative Brayton cycle has a higher reactor inlet temperature (RIT) than 500°C and is limited by reactor materials. Combined cycle of HTGR not only can solve the problem of high RIT, but also can get a higher cycle efficiency than 50%. In this paper an accurate model of combined cycle consisting of topping Brayton cycle, bottoming Rankine cycle and heat recovery steam generator (HRSG) was established. In terms of new model of combined cycle, this paper analyzed the main properties of simple combined cycle. And put forward two optimization schemes improving the cycle efficiency of combined cycle.

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Modeling and Testing of a Novel Ultra-Low Temperature sCO2 Opposing Piston Expander

10.1115/gt2021-60251 ◽

2021 ◽

Author(s):

Joshua Schmitt ◽

Jordan Nielson

Keyword(s):

Low Temperature ◽

Full Scale ◽

Small Scale ◽

Brayton Cycle ◽

The Novel ◽

Transient Effects ◽

Cold Temperatures ◽

Piston Cylinder ◽

Southwest Research Institute ◽

Cycle Efficiency

Abstract Southwest Research Institute (SwRI) along with Thermal Tech Holdings (TTH) have modeled, built, and tested a piston expander for generating power from low temperature heat sources. The piston was developed with the goal of creating an engine that operates as a recuperated sCO2 Ericsson cycle. A cycle model based on fluid properties from REFPROP is applied for various hot and cold temperatures to demonstrate the potential of the novel expander to improve cycle efficiency. Cycle modeling results demonstrate the potential improvements in cycle efficiency when compared to the sCO2 Brayton cycle. Small-scale bench testing is used to validate the novel piston concept for achieving a sCO2 Ericsson cycle. The concept is scaled up to a full-sized, opposing piston cylinder that acts as an expander in the theoretical Ericsson cycle. Testing is performed on the full-scale piston cylinder for a variety of inlet temperatures and pressures. The full-scale tests are run continuously to track the transient effects. The results of the full-scale test are discussed. The expander piston cylinder test results show high temperatures at the outlet, better than the ideal sCO2 Brayton cycle, but less than an ideal recuperated sCO2 Ericsson cycle. Comparisons are made to demonstrate the projected cycle efficiency improvements over a sCO2 Brayton cycle.

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