Proportional-Integral Disturbance Observer of Nuclear Reactors

2020 ◽  
Author(s):  
Zhe Dong
Keyword(s):  
Disturbance Observer ◽  
Nuclear Reactors ◽  
Coolant Temperature ◽  
State Variables ◽  
Theoretic Analysis ◽  
Primary Coolant ◽  
Nuclear Heating Reactor ◽  
Neutron Kinetics ◽  
Proportional Integral ◽  
Nuclear Heating

Abstract A proportional-integral disturbance observer (PI-DO) for monitoring nuclear reactors is newly proposed, which is driven by the measurements of neutron flux and coolant temperature at reactor inlet as well as their integrations. This PI-DO provides a globally asymptotic estimation with a bounded steady-state error for the reactor key process variables as well as the total disturbances in channels of the neutron kinetics and primary coolant thermal-hydraulics. Moreover, the PI-DO is applied to reconstruct the unmeasurable state variables and total disturbances of a nuclear heating reactor (NHR). Numerical simulation results not only verify the theoretic analysis but also show both the satisfactory performance and the influence of observer parameters.

Construction of an Elementary Model for the Dynamic Analysis of a Pressurized Water Reactor

2013 ◽  
Vol 284-287 ◽  
pp. 652-656 ◽  
Author(s):  
Chiung Wen Tsai ◽  
Chun Kuan Shih ◽  
Jong Rong Wang
Keyword(s):  
Transfer Functions ◽  
Feedback Loops ◽  
Dynamic Responses ◽  
Coolant Temperature ◽  
Inlet Temperature ◽  
Pressurized Water Reactor ◽  
Elementary Model ◽  
Pressurized Water ◽  
Water Reactor ◽  
Neutron Kinetics

A lumped-parameter numerical model was constructed based on the conservation laws of mass and energy and the point neutron kinetics with 6 groups of delayed neutron to represent the dynamics of primary loop of a pressurized water reactor (PWR) core. On the viewpoint of control theory, the coupled phenomenon of neutron kinetics and thermohydraulics can be recognized as a dynamic system with feedback loops which is caused by the Doppler effect and the coolant temperature difference. Scilab was implemented to representing the equivalent transfer functions and associated feedback loops of a PWR core. The dynamic responses were performed by the perturbations of coolant inlet flow, coolant inlet temperature, and reactivity insertion.

The fuel assembly of the 5 MWt Nuclear Heating Reactor

1995 ◽  
Vol 154 (2) ◽  
pp. 219-223
Author(s):  
Y. Xu ◽  
X. Wei ◽  
Z. Zhang
Keyword(s):  
Fuel Assembly ◽  
Nuclear Heating Reactor ◽  
Nuclear Heating

Dynamic Modeling of the NSSS Based on NHR200-II Nuclear Heating Reactor

2018 ◽  
Author(s):  
Zhe Dong ◽  
Yifei Pan ◽  
Miao Liu ◽  
Xiaojin Huang
Keyword(s):  
Control System ◽  
System Design ◽  
Dynamic Modeling ◽  
Primary Circuit ◽  
Control System Design ◽  
Plant Design ◽  
Pressurized Water ◽  
Nuclear Heating Reactor ◽  
System Verification ◽  
Nuclear Heating

The nuclear heating reactor (NHR) is a typical integral pressurized water reactor (iPWR) developed by the institute of nuclear and new energy technology (INET) of Tsinghua University, which has the safety advanced features such as the primary circuit integral arrangement, full-range natural circulation, self-pressurization. Power-level control is crucial for the operational stability and efficiency of the NHR, and the dynamic modeling is a basis for control system design and verification. From the conservation laws of mass, energy and momentum, a lumped-parameter dynamical model is proposed for the nuclear steam supply system (NSSS) based on the 200MWth nuclear heating reactor II (NHR200-II). The steady-state model validation is given by the comparing the parameter values of this model and that for plant design. Then, both the open-loop responses under the disturbances of reactivity and coolant flowrates as well as the closed-loop responses under the case of power ramp are given, where the rationality of the responses are analyzed from the viewpoint of plant physics and thermal-hydraulics. This model can be utilized for not only the control system design but also the development of a real-time simulator for the hardware-in-loop control system verification.

Super-twisting disturbance observer-based finite- time attitude stabilization of flexible spacecraft subject to complex disturbances

2018 ◽  
Vol 25 (5) ◽  
pp. 1008-1018 ◽  
Author(s):  
Ruidong Yan ◽  
Zhong Wu
Keyword(s):  
Attitude Control ◽  
Disturbance Observer ◽  
Sliding Mode ◽  
State Variables ◽  
Attitude Dynamics ◽  
Attitude Control System ◽  
Terminal Sliding Mode ◽  
Nonlinear Disturbance Observer ◽  
Attitude Stabilization ◽  
Nonsingular Terminal Sliding Mode

There exist complex disturbances in the attitude control system of flexible spacecrafts, such as space environmental disturbances, flexible vibrations, inertia uncertainties, payload motions, etc. To suppress the effects of these disturbances on the performance of attitude stabilization, a super-twisting disturbance observer (STDO)-based nonsingular terminal sliding mode controller (NTSMC) is proposed in this paper. First, STDO is designed for a second-order dynamical system constructed by applying the lumped disturbance and its integral as state variables, and applying the integral as virtual measurement. Since the virtual measurement is obtained by integrating the inverse attitude dynamics, STDO not only avoids the differential operation of angular velocity, but also fully utilizes the information of a nonlinear model. By combining STDO with NTSMC, a composite controller is designed to achieve high-accuracy spacecraft attitude stabilization. Since most of the disturbances are compensated for by a STDO-based feedforward compensator, only a small switching gain is required to deal with the residual disturbances and uncertainties. Thus, the chattering phenomenon of the controller can be alleviated to a great extent. Finally, numerical simulations for the comparison between STDO-based NTSMC and nonlinear disturbance observer-based NTSMC are carried out in the presence of complex disturbances to verify the effectiveness of the proposed approach.

A Simulation of Small Break Loss of Coolant Accident in Nuclear Heating Reactor Based on RELAP5

2018 ◽  
Author(s):  
Meng Lu ◽  
Heng Xie
Keyword(s):  
Thermal Power ◽  
Heat Removal ◽  
Injection System ◽  
Water Volume ◽  
Nuclear Heating Reactor ◽  
Removal Capacity ◽  
Loss Of Coolant ◽  
Nuclear Heating ◽  
Residual Heat

Nuclear heating reactor is integrated designed without main pump and safety injection system. The loss of coolant accidents are mainly in the form of small break LOCA. As no safety injection system is designed for coolant makeup, the water volume in the reactor vessel is critical since it determines whether the reactor will be submerged during the whole scenario. Therefore, the study on coolant loss in this pool system is indispensable. The RELAP5 code has been developed for best-estimate transient simulation of light water reactor coolant systems during postulated accidents. The long term effect in nuclear heating reactor is important. In this paper we investigated the influential factors on SBLOCA scenario and found the long term residual heat removal capacity is decisive in determining the loss of coolant. The residual heat removal capacity should be greater than 2% of reactor thermal power if ensuring the core submerged in the long run.

Status of District Heating Reactor and its Development Prospects in China

2018 ◽  
Author(s):  
Jing Zhao ◽  
Fei Xie ◽  
Zhihong Liu
Keyword(s):  
Low Temperature ◽  
Nuclear Reactor ◽  
District Heating ◽  
Heating System ◽  
Inherent Safety ◽  
Nuclear Heating Reactor ◽  
New Type ◽  
Nuclear Heating ◽  
Safety Features ◽  
Temperature Heating

Nuclear heating reactor is a new type of power plant that uses nuclear energy as heat source. Low temperature nuclear heating reactor should be the forerunner and main force for developing nuclear heating plant in China. Due to the lower water temperature required by the heating system, this dedicated, non-power generating nuclear reactor works at low temperatures and pressures with inherent safety features. The design, construction and operation of the nuclear heating reactors in various countries in the world were reviewed in this paper, and China’s new demonstration nuclear heating project and NHR-200 low-temperature heating reactor which would be used was discussed in the paper. We put forward the developing route and suggestion for the development of low-temperature heating reactor in China.

Some features of the nuclear heating reactor (NHR) design in China

1995 ◽  
Vol 155 (3) ◽  
pp. 597-602 ◽  
Author(s):  
Shi Yongchang ◽  
Chang Huajian ◽  
Dong Duo
Keyword(s):  
Nuclear Heating Reactor ◽  
Nuclear Heating
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