New steam generation system for lead-cooled fast reactors, based on steam re-circulation through ejector

A thermal energy storage system is a critical component in concentrating solar power plants (CSPP), owing to which concentrating solar power (CSP) has superiorities over photovoltaic and wind power. Currently, the sole thermal energy storage (TES) system which is commercially applied to parabolic trough solar power (PTSP) plants worldwide is the two-tank indirect TES. In this study, the dynamic models of a solar field (SF), a two-tank indirect TES system, and a steam generation system (SGS) in a PTSP plant were developed and validated. Control and operation strategies on a clear day and a cloudy day were provided, and the dynamic simulations of the coupled operation using actual meteorological data were conducted. The influence of the two-tank indirect TES system on the dynamic characteristics of SGS on a system level was analyzed. Other key parameter variations were also presented. The results show that during the transition from the charge to the discharge process, the steam parameters slowly decrease. The variation of the molten salt height is further affected by the molten salt mass flow rate at the inlet and outlet of the molten salt tank. We adopted the PI control to adjust the thermal oil mass flow rate, thermal oil temperature, and water height. The developed dynamic models are useful in guiding system operation and control.

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Research progress on novel solar steam generation system based on black nanomaterials

The Canadian Journal of Chemical Engineering ◽

10.1002/cjce.23315 ◽

2018 ◽

Vol 96 (10) ◽

pp. 2086-2099 ◽

Cited By ~ 4

Author(s):

Chao Xu ◽

Qian Yang ◽

Fuxian Wang ◽

Xiaoming Fang ◽

Zhengguo Zhang

Keyword(s):

Research Progress ◽

Steam Generation ◽

Generation System ◽

Solar Steam Generation

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Brayton Cycle As an Alternate Power Conversion Option for Sodium Cooled Fast Reactor

Volume 2: Combustion, Fuels, and Emissions; Renewable Energy: Solar and Wind; Inlets and Exhausts; Emerging Technologies: Hybrid Electric Propulsion and Alternate Power Generation; GT Operation and Maintenance; Materials and Manufacturing (Including Coatings, Composites, CMCs, Additive Manufacturing); Analytics and Digital Solutions for Gas Turbines/Rotating Machinery ◽

10.1115/gtindia2019-2455 ◽

2019 ◽

Author(s):

Jofred Joseph ◽

Satish Kumar ◽

Tanmay Vasal ◽

N. Theivarajan

Keyword(s):

Power Conversion ◽

Rankine Cycle ◽

Inlet Temperature ◽

Brayton Cycle ◽

Generation System ◽

Fast Reactors ◽

Turbine Inlet Temperature ◽

Power Cycle ◽

Power Generation System ◽

Cycle Efficiency

Abstract Enhancing the safety and economic competitiveness are major objectives in the development of advanced reactor designs with emphasis on the design of systems or components of the nuclear systems. Innovative power cycle development is another potential option to achieve these objectives. Sodium cooled fast reactor (SFR) is one among the six reactor design concepts identified by the Gen IV International Forum for development to meet the technology goals for new nuclear energy system. Similar to the power cycle used in conventional fossil fuel based thermal power plants, sodium-cooled fast reactors have adopted the Rankine cycle based power conversion system. However, the possibility of sodium water reaction is a major concern and it becomes necessary to adopt means of early detection of leaks and isolation of the affected SG module for mitigating any adverse impact of sodium water reaction. The high exothermic nature of the reaction calls for introducing an intermediate sodium heat transport loop, leading to high overall plant cost hindering commercialization of sodium fast reactors. The Indian Prototype Fast Breeder Reactor (PFBR) also uses Rankine cycle in the power generation system. The superheated steam temperature has been set at 490 degree Celsius based on optimisation studies and material limitations. Additional Fast Breeder reactors are planned in near future and further work is being done to develop more advanced sodium cooled fast reactors. The closed Brayton cycle is a promising alternative to conventional Rankine cycle. By selecting an inert gas or a gas with milder reaction with sodium, the vigorous sodium water reaction can be avoided and significant cost savings in the turbine island can be achieved as gas turbine power conversion systems are of much smaller size than comparable steam turbine systems due to their higher power density. In the study, various Brayton cycle designs on different working gases have been explored. Supercritical-CO2 (s-CO2), helium and nitrogen cycle designs are analyzed and compared in terms of cycle efficiency, component performance and physical size. The thermal efficiencies at the turbine inlet temperature of Indian PFBR have been compared for Rankine cycle and Brayton cycle based on different working fluids. Also binary mixtures of different gases are investigated to develop a more safe and efficient power generation system. Helium does not interact with sodium and other structural materials even at very high temperatures but its thermal performance is low when compared to other fluids. Nitrogen being an inert gas does not react with sodium and can serve to utilise existing turbomachinery because of the similarity with atmospheric air. The supercritical CO2 based cycle has shown best thermodynamic performance and efficiency when compared to other Brayton cycles for the turbine inlet temperature of Indian PFBR. CO2 also reacts with sodium but the reaction is mild compared to sodium water reaction. The cycle efficiency of the s-CO2 cycle can be further improved by adopting multiple reheating, inter cooling and recuperation.

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Nonlinear Dynamic Model of a Fluidized-Bed Steam Generation System

Journal of Engineering for Power ◽

10.1115/1.3230224 ◽

1980 ◽

Vol 102 (1) ◽

pp. 202-208 ◽

Cited By ~ 4

Author(s):

A. Ray ◽

D. A. Berkowitz ◽

V. H. Sumaria

Keyword(s):

Fluidized Bed ◽

Dynamic Model ◽

Controller Design ◽

Digital Simulation ◽

Steam Generation ◽

Generation System ◽

Nonlinear Dynamic Model ◽

Continuous Time Model ◽

Design Data ◽

Time Model

A dynamic model of an atmospheric pressure fluidized-bed steam generation system is presented which allows digital simulation and analytical controller design. The nonlinear, time-invariant, deterministic, continuous-time model is derived in state-space form from conservation relations, empirical correlations and system design data. The model has been verified for steady-state and transient performance with measured data from experimental test runs. Transient responses of several process variables, following independent step disturbances in coal feed rate and air flow, are illustrated.

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