Thermodynamic analysis and optimization of a Closed Regenerative Brayton Cycle for nuclear space power systems

Ribeiro, Guilherme B.; Filho, Francisco A. Braz; Guimarães, Lamartine Nogueira Frutuoso

doi:10.1016/j.applthermaleng.2015.06.093

Cited by 39 publications

(13 citation statements)

References 16 publications

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“…Similarly, the NASA Space Station Freedom selected a solar-powered CBC for space power system application. To this end, there are several pieces of research and development programs been deployed to show the technology readiness of the closedcycle gas turbine in aerospace application [15,24,28].…”

Section: The Brayton Closed-cycle Enginesmentioning

confidence: 99%

Feasibility of a Helium Closed-Cycle Gas Turbine for UAV Propulsion

2020

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When selecting a design for an unmanned aerial vehicle, the choice of the propulsion system is vital in terms of mission requirements, sustainability, usability, noise, controllability, reliability and technology readiness level (TRL). This study analyses the various propulsion systems used in unmanned aerial vehicles (UAVs), paying particular focus on the closed-cycle propulsion systems. The study also investigates the feasibility of using helium closed-cycle gas turbines for UAV propulsion, highlighting the merits and demerits of helium closed-cycle gas turbines. Some of the advantages mentioned include high payload, low noise and high altitude mission ability; while the major drawbacks include a heat sink, nuclear hazard radiation and the shield weight. A preliminary assessment of the cycle showed that a pressure ratio of 4, turbine entry temperature (TET) of 800 °C and mass flow of 50 kg/s could be used to achieve a lightweight helium closed-cycle gas turbine design for UAV mission considering component design constraints.

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Section: The Brayton Closed-cycle Enginesmentioning

confidence: 99%

Feasibility of a Helium Closed-Cycle Gas Turbine for UAV Propulsion

2020

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“…Some scholars have also studied space power plants with FTT theory [45][46][47][48][49]. References [45][46][47][48][49] established simple and regenerative CBC models in space nuclear plants and applied the thermal conductances of the HEXs to predict the energy conversion performance and analyze the effects of thermal conductances on the performances of the plants.…”

Section: Introductionmentioning

confidence: 99%

Optimal Heat Exchanger Area Distribution and Low-Temperature Heat Sink Temperature for Power Optimization of an Endoreversible Space Carnot Cycle

Wang

Chen

et al. 2021

Entropy

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Using finite-time thermodynamics, a model of an endoreversible Carnot cycle for a space power plant is established in this paper. The expressions of the cycle power output and thermal efficiency are derived. Using numerical calculations and taking the cycle power output as the optimization objective, the surface area distributions of three heat exchangers are optimized, and the maximum power output is obtained when the total heat transfer area of the three heat exchangers of the whole plant is fixed. Furthermore, the double-maximum power output is obtained by optimizing the temperature of a low-temperature heat sink. Finally, the influences of fixed plant parameters on the maximum power output performance are analyzed. The results show that there is an optimal temperature of the low-temperature heat sink and a couple of optimal area distributions that allow one to obtain the double-maximum power output. The results obtained have some guidelines for the design and optimization of actual space power plants.

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“…Nonetheless, the assistant thaw system is necessary, and it would increase the system complexity and specific mass. The gas‐cooled space reactor can achieve a fairly low specific mass benefiting from the closed direct Brayton cycle 10 . It offers the convenience of only a single coolant phase in both the reactor core and the thermal‐to‐electric conversion system, leading to simpler system facilities.…”

Section: Introductionmentioning

confidence: 99%

Thermal‐hydraulic analysis of an open‐grid megawatt gas‐cooled space nuclear reactor core

et al. 2020

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Summary The development of deep space exploration requires space nuclear reactor with higher power and better endurance. In order to meet the increasing high power requirements for space applications, an Open‐grid MEgawatt Gas‐cooled spAce nuclear reactor (OMEGA) is proposed in the paper, which is featured with low specific mass and high energy conversion coefficients. A set of models, including neutron kinetics model, reactivity feedback model and heat transfer model are established. Besides, the space nuclear system analysis code (System Analysis code of MEgawatt gas‐cooled space Reactor [SAMER]) is developed by finite volume method and staggered grid technique for the preliminary safety analysis of the OMEGA conceptual design. Furthermore, the calculation results provided by the SAMER code agree well with the computational fluid dynamics simulation, validating the reliability of the code. Moreover, the transient thermal‐hydraulic responses of the OMEGA under the unprotected reactivity insertion accident (URIA) and the unprotected loss of partial coolant flow accident (LOFA) are obtained and analyzed. The maximum fuel temperature after the URIA has a margin of 262 K from the fuel temperature limit value. The total power after the LOFA is about 68.7% of the rated power, meanwhile, the fuel radial temperature distribution tends to be more uniform with the fuel average temperature unchanged. It can be found that the OMEGA design shows satisfactory safety characteristic and reliability under the URIA and the LOFA scenarios. This paper is the stage summary of the conceptual design work of the OMEGA, and it may provide useful reference for megawatt space nuclear system design and thermal‐hydraulic analysis.

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Thermodynamic analysis and optimization of a Closed Regenerative Brayton Cycle for nuclear space power systems

Cited by 39 publications

References 16 publications

Feasibility of a Helium Closed-Cycle Gas Turbine for UAV Propulsion

Feasibility of a Helium Closed-Cycle Gas Turbine for UAV Propulsion

Optimal Heat Exchanger Area Distribution and Low-Temperature Heat Sink Temperature for Power Optimization of an Endoreversible Space Carnot Cycle

Thermal‐hydraulic analysis of an open‐grid megawatt gas‐cooled space nuclear reactor core

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