Dynamic Control Analysis of the AFR-100 SMR SFR With a Supercritical CO2 Cycle and Dry Air Cooling: Part I — Plant Control Optimization

2018 ◽  
Author(s):  
Anton Moisseytsev ◽  
James J. Sienicki
Keyword(s):  
Dynamic Control ◽  
Air Cooling ◽  
Control Analysis ◽  
Brayton Cycle ◽  
Control Mechanisms ◽  
Dry Air ◽  
Load Following ◽  
Control Optimization ◽  
Cooling Part ◽  
Plant Control

Supercritical carbon dioxide Brayton cycle power converters can benefit advanced nuclear reactors, as well as small modular reactors, by reducing the plant cost and increasing plant electrical output. The sCO2 cycles can also be designed for operation under direct dry air cooling. This paper presents the results of the coupled control analysis of a sCO2 cycle for a 100 MWe sodium-cooled fast reactor. The plant control mechanisms were investigated and optimized for load following operation.

Dynamic Control Analysis of the AFR-100 SMR SFR With a Supercritical CO2 Cycle and Dry Air Cooling: Part II — Plant Control Under Varying Ambient Conditions

2018 ◽  
Author(s):  
Anton Moisseytsev ◽  
James J. Sienicki
Keyword(s):  
Dynamic Control ◽  
Ambient Air ◽  
Air Cooling ◽  
Control Analysis ◽  
Brayton Cycle ◽  
Ambient Conditions ◽  
Dry Air ◽  
Air Temperatures ◽  
Cooling Part ◽  
Plant Control

Supercritical carbon dioxide Brayton cycle power converters can benefit advanced nuclear reactors, as well as small modular reactors, by reducing the plant cost and increasing plant electrical output. The sCO2 cycles can also be designed for operation under direct dry air cooling. The paper presents the results of the coupled control analysis of a sCO2 cycle for a 100 MWe sodium-cooled fast reactor under changing ambient air temperatures. The optimum plant operation modes are identified.

Heat Exchanger Options for Dry Air Cooling for the sCO2 Brayton Cycle

2017 ◽  
Author(s):  
Anton Moisseytsev ◽  
Qiuping Lv ◽  
James J. Sienicki
Keyword(s):  
Heat Exchanger ◽  
Heat Exchangers ◽  
Cost Effective ◽  
Finned Tube ◽  
Air Cooling ◽  
Brayton Cycle ◽  
Dry Air ◽  
Air Atmosphere ◽  
Air Cooler ◽  
Forced Air

The capability to utilize dry air cooling by which heat is directly rejected to the air atmosphere heat sink is one of the benefits of the supercritical carbon dioxide (sCO2) energy conversion cycle. For the selection and analysis of the heat exchanger options for dry air cooling applications for the sCO2 cycle, two leading forced air flow design approaches have been identified and analyzed for this application; an air cooler consisting of modular finned tube air coolers; and an air cooler consisting of modular compact diffusion-bonded heat exchangers. The commercially available modular finned tube air cooler is found to be more cost effective and is selected as the reference for dry air cooling.

scholarly journals Dry-Cooled Supercritical CO2 Power for Advanced Nuclear Reactors

2014 ◽  
Author(s):  
T. M. Conboy ◽  
M. D. Carlson ◽  
G. E. Rochau
Keyword(s):  
Power Systems ◽  
Nuclear Energy ◽  
Energy Systems ◽  
Air Cooling ◽  
Brayton Cycle ◽  
Heat Rejection ◽  
Ambient Temperatures ◽  
Power Cycle ◽  
Dry Air ◽  
Compressor Inlet

Currently, waste heat rejection from electrical power systems accounts for the largest fraction of water withdrawals from the US fresh water table. Siting of nuclear power plants is limited to areas with access to a large natural supply of fresh or sea water. Due to a rise in energy needs and increased concern over environmental impact, dry air cooling systems are poised to play a large role in the future energy economy. In practice, the implementation of dry air-cooled condensing systems at steam plants has proven to be capital-intensive and requires the power cycle to take a significant efficiency penalty. These shortcomings are fundamental to dry-air steam condensation, which must occur at a fixed temperature. Closed-cycle gas turbines are an alternative to the conventional steam Rankine plant that allow for much improved dry heat rejection compatibility. Recent research into advanced nuclear energy systems has identified the supercritical CO2 (s-CO2) Brayton cycle in particular as a viable candidate for many proposed reactor types. The s-CO2 Brayton cycle can maintain superior thermal efficiency over a wide range of ambient temperatures, making these power systems ideally suited for dry air cooling, even in warm climates. For an SFR operating at 550°C, thermal efficiency is calculated to be 43% with a 50°C compressor inlet temperature. This is achieved by raising CO2 compressor inlet pressure in response to rising ambient temperatures. Preliminary design studies have shown that s-CO2 power cycle hardware will be compact and therefore well-matched to near-term and advanced integral SMR designs. These advantages also extend to the cooling plant, where it is estimated that dry cooling towers for an SFR-coupled s-CO2 power cycle will be similar in cost and scale to the evaporative cooling tower for an LWR. The projected benefits of the s-CO2 power cycle coupled to dry air heat rejection may enable the long-awaited rise of next-generation nuclear energy systems, while re-drawing the map for siting of small and large nuclear energy systems.

Dry Air Cooling and the sCO2 Brayton Cycle

2017 ◽  
Author(s):  
James J. Sienicki ◽  
Anton Moisseytsev ◽  
Qiuping Lv
Keyword(s):  
Nuclear Power ◽  
High Efficiency ◽  
Electrical Power ◽  
Cost Effective ◽  
Finned Tube ◽  
Inlet Temperature ◽  
Air Cooling ◽  
Brayton Cycle ◽  
Water Cooling ◽  
Dry Air

Commercially available and cost effective finned tube air coolers are an enabling technology that makes practical dry air cooling for the supercritical carbon dioxide (sCO2) Brayton cycle by which heat is directly rejected from CO2 to the air atmospheric heat sink. With dry air cooling, sCO2 Brayton cycle conditions need to be re-optimized to increase the main compressor inlet temperature and pressure (e.g., 35 °C and 8.2 MPa) relative to water cooling to limit the air cooler size to a practical value, and to increase the compressor outlet pressure (e.g., 25 MPa) to maintain a high efficiency. With reoptimization, the plant efficiency for the AFR-100 Sodium-Cooled Fast Reactor Nuclear Power Plant (NPP) is similar to that with once-through water cooling, while the NPP capital cost per unit output electrical power ($/kWe) is roughly estimated to be only 2 % greater. For the AFR-100 application, no unique benefit is identified for the sCO2 Brayton cycle relative to the superheated steam cycle with respect to the capability to use dry air cooling.

High Flux Reactor Review and Reactivity Control Analysis

2021 ◽  
Author(s):  
Wang Lin ◽  
Xu Wei ◽  
Xie Fei
Keyword(s):  
Control Analysis ◽  
Control Mechanisms ◽  
General Description ◽  
High Flux ◽  
High Flux Reactor ◽  
Wide Range ◽  
Versatile Tool ◽  
Flux Reactor ◽  
Safety Operation ◽  
Reactivity Insertion

Abstract For over 60 years, research reactors have provided the world with a versatile tool to test materials and promote irradiation research, as well as to produce radioisotopes for medical treatments. The High Flux Reactor (HFR), as a water moderated and cooled, beryllium-reflected reactor has awarded more attention in recent years. There is a wide range of designs and applications for HFRs that based on their own situation to meet research requirements. For the purpose of reducing the volume and mass of the reactor, as well as ensuring the safety operation, it is necessary to determine the most effective reactivity control scheme, and analyze the corresponding reactivity insertion accidents. This paper is going to investigate typical high flux reactors within the same type with HFETR, summarize general description and characteristics, the uses of the high flux reactor, and reactivity control mechanisms. In addition, the associated reactivity insertion accidents were presented and analyzed. The analysis result will provide some references to further design and construction of high flux reactor.

Dynamic control mechanisms for revenue management with flexible products

2010 ◽  
Vol 37 (11) ◽  
pp. 2027-2039 ◽  
Author(s):  
Anita Petrick ◽  
Jochen Gönsch ◽  
Claudius Steinhardt ◽  
Robert Klein
Keyword(s):  
Revenue Management ◽  
Dynamic Control ◽  
Control Mechanisms ◽  
Flexible Products

scholarly journals Handedness results from complementary hemispheric dominance, not global hemispheric dominance: evidence from mechanically coupled bilateral movements

2018 ◽  
Vol 120 (2) ◽  
pp. 729-740 ◽  
Author(s):  
Elizabeth J. Woytowicz ◽  
Kelly P. Westlake ◽  
Jill Whitall ◽  
Robert L. Sainburg
Keyword(s):  
Motor Control ◽  
Dynamic Control ◽  
The Other ◽  
Hemispheric Dominance ◽  
Control Mechanisms ◽  
Left Hand ◽  
Right Hand ◽  
Other Hand ◽  
Task Component ◽  
The Right

Two contrasting views of handedness can be described as 1) complementary dominance, in which each hemisphere is specialized for different aspects of motor control, and 2) global dominance, in which the hemisphere contralateral to the dominant arm is specialized for all aspects of motor control. The present study sought to determine which motor lateralization hypothesis best predicts motor performance during common bilateral task of stabilizing an object (e.g., bread) with one hand while applying forces to the object (e.g., slicing) using the other hand. We designed an experimental equivalent of this task, performed in a virtual environment with the unseen arms supported by frictionless air-sleds. The hands were connected by a spring, and the task was to maintain the position of one hand while moving the other hand to a target. Thus the reaching hand was required to take account of the spring load to make smooth and accurate trajectories, while the stabilizer hand was required to impede the spring load to keep a constant position. Right-handed subjects performed two task sessions (right-hand reach and left-hand stabilize; left-hand reach and right-hand stabilize) with the order of the sessions counterbalanced between groups. Our results indicate a hand by task-component interaction such that the right hand showed straighter reaching performance whereas the left hand showed more stable holding performance. These findings provide support for the complementary dominance hypothesis and suggest that the specializations of each cerebral hemisphere for impedance and dynamic control mechanisms are expressed during bilateral interactive tasks. NEW & NOTEWORTHY We provide evidence for interlimb differences in bilateral coordination of reaching and stabilizing functions, demonstrating an advantage for the dominant and nondominant arms for distinct features of control. These results provide the first evidence for complementary specializations of each limb-hemisphere system for different aspects of control within the context of a complementary bilateral task.

Sign in / Sign up

Export Citation Format

Share Document