Stability Analysis of Supercritical Water-Cooled Reactors Using Two-Zone and Three-Zone Lumped Parameter Models

Highlights• Comparative analysis of lumped parameter models with two and three-zone configurations has been carried out.• Investigations into the stability of thermal hydraulic systems have been completed.• The study has produced stability maps illustrating how system stability varies with different operational parameters.• The research includes a comprehensive mathematical formulation of a three-zone lumped parameter model.• The study's findings endorse the two-zone lumped parameter model as the more favorable option based on the analysis conducted.

Recent trends in metallic nanocomposites for sensing and electrochemical devices

Recent years have witnessed an exponential rise in the development of sensor devices with enhanced characteristics. The research arena of sensing has been devoted to increasing the sensitivity, stability, scalability, selectivity, responsiveness, reactivity, cost-effectiveness, and ease of operation. Nanocomposites, owing to their size and shape-dependent interatomic bond lengths, exceptional mechanical properties, high chemical reactivity, good optical and electronic features, specific biocompatibility, and other excellent physiochemical properties, have exhibited immense potential in the intensification of these properties in sensors. Electrochemical devices employed for sensing have emerged as one of the most significant types of sensors. Electrochemical sensors are characterized by their reactivity, which depends on electrochemical signals, and their functionality is determined by ion and electron transportation.

Design of Low-Cost Solar Powered E-Rickshaw: A Case Study

Concern has increased over the use of fossil fuels in passenger transport vehicle. In Indian cities, autorickshaws are making a huge quantity of air effluence. There are two types of rickshaw are seen running on the road, first one manual type which is pulled by human being and another one is motorized which is using electricity. Here, the proposed e-Rickshaw is designed with respect to a stable design at optimum ground clearance and its aerodynamics. The functionality, construction and mechanisms of solar power-driven rickshaw are briefly discussed in this paper. This paper shows how this conceptual autorickshaw provides passenger comfortable and safe ride upto a speed of 25–30 km/h.

Nonlinear analysis of coupled neutronic-thermohydraulic stability characteristics of supercritical water-cooled reactor

The Supercritical Water-Cooled Reactor (SCWR) exhibits significant changes in thermophysical properties of the coolant, but its dynamic characteristics are different from existing reactors, due to the supercritical conditions of the coolant. This necessitates the study of the stability behaviour of SCWR, which requires a dynamic model of the reactor. In this work, a simple unsteady lumped parameter model (LPM) for SCWR has been developed. The LPM includes point reactor kinetics for neutron balance and a two-region model for fuel and coolant thermal hydraulics. The two regions are separated from each other by a boundary that depends on the pseudocritical temperature of the coolant. Regions of stable and unstable operation are identified in the parameter space by linear stability analysis. Bifurcation analysis is carried out to capture the non-linear dynamics of the system

Thermal hydraulic stability analysis of supercritical water-cooled reactor under the effect of seismic-wave acceleration

The effect of seismic waves on the SCWR is investigated in this work. Only vertical motion has been considered in the current study to reduce complexity. A sinusoidal curve representing the vertical seismic acceleration has been used for the analysis. The axial power distribution, the sine wave's effects, and the degree of instability in the system's initial state, controlled by the ratio of power-to-flow at its core, will be investigated. The preliminary results are described in this paper using simpler models and substantial computed outcomes. The main goal of this research is to provide quantitative data that can be used to identify the critical effects of seismic waves on the SCWR system utilizing LPM. To achieve the goal, the short thermal-hydraulic in-house code is employed, which has been adjusted to account for external acceleration and gravity.

Study on Design of Scaled Down Test Facilities for Investigation of Instabilities in Supercritical Water Reactor

TSupercritical Water Reactor (SCWR) proposes higher thermal efficiency and simpler plant design compared to modern Boiling Water Reactors. High pressure, temperature and power requirement in SCWR, however, escalates the cost of an experimental facility significantly. Present work, therefore, focuses on designing downscaled test facilities for stability analysis of SCWR. The facilities are conceptualized to model the European reference design of SCWR under both forced and natural circulation condition. R-134a is identified as the scaling fluids through fluid-to-fluid modeling, along with two others from literature. Similarity variables are obtained following two different approaches, starting from fundamental conservation equations. Dimensional and non-dimensional representations of important geometric, kinematic and dynamic parameters are evaluated and compared. Comparisons between two different. 

Modelling and Performance Simulation of a Solar Powered e-rickshaw Retrofit in the North East Region of India

E-rickshaws, which are highly popular in developing countries like India, are categorized as a primary source of income for many commercial drivers/operators. Though conventional e-rickshaws may seem environmentally friendly as they are charged through the national electricity grid, a significant portion of the electricity from the grid is contributed by thermal coal-based powerplants that cause substantial carbon emissions. Additionally, the current study focuses on the North-Eastern region of India, where charging e-rickshaws are a problem primarily due to the erratic supply of electricity from the grid. To tackle this, some operators have integrated their e-rickshaws with solar PV modules to increase operation time and reduce charging costs. Most e-rickshaw operators are hesitant to adapt to this technology. Thus, to address this problem, this paper presents a perspective through simulation and mathematical.

Quantum Impact on Organizational Performance

Organisations thrive to go global as globalisation provides businesses with increased revenue, hire new talent, access the latest technology and investments. By doing so organizations need for solving complex problems (permutations & combinations) and security issues at the same global scale also increases. The possible solution for solving these complex problems is by using a Quantum Computer. This chapter explores the details of how Quantum computers solve a lot of unanswered questions in the fields of cryptography, cyber security, chemical, pharma, bio-medical, finance and many fields that require intense complex calculations. The author explains further about the impact such computational power has on organisations while simultaneously discussing implementation, cost analysis, challenges and the road ahead for the organisations that take the Quantum Leap.

Generation of Temperature Profile by Artificial Neural Network in Flow of Non-Newtonian Third Grade Fluid Through Two Parallel Plates Under Noisy Data

Artificial neural network (ANN) is explored to generate temperature profile for a non-Newtonian third grade fluid flowing through two parallel plates. Both the plates are supplied with a constant and uniform heat flux. A semi-analytical approach (Least Square Method LSM) is used to solve the governing equations under with required boundary conditions. The velocity and the temperature profile obtained from the LSM are perturbed by different levels of noise to mimic error in measurement. Thus, velocity and temperature profiles are fed into ANN for training. In ANN, scaled conjugate gradient (SCG) algorithm is used for training the neurons. Once training of ANN is completed, an unknown velocity profile is fed as input, and the temperature profile is obtained as output. The temperature profile obtained from ANN found to be in very good agreement with the LSM results.

Parametric Analysis of Coupled Thermal Hydraulic Instabilities in Forced Flow Channel Using Reduced-Order Three-Zone Model

One of the significant issues of supercritical water reactor (SCWR) is the variation of coolant density along its axial direction of flow, which further creates a stability issue in the reactor. This causes the dynamic instability in the coolant channel. Present work is focused to study the parametric effects on the stability of the system using a simplified three-zone lumped parameter model by considering the neutronics coupled with thermal hydraulics. The coolant channel is divided into three zones, namely heavy fluid region, light fluid region, and intermediate heavy and light mixture fluid region. The interface of these hypothetical regions is separated by time dependence boundaries. A set of governing equations are solved for the individual zones that provide another set of algebraic and ODEs, which has coolant enthalpy and the length of each boundary as a primary variable. 

Coupled-neutronic-thermalhydraulic stability appraisal of supercritical forced flow channels following lumped parameter approach

Possible appearance of instabilities is of major concern for the operation of Supercritical Water Reactor (SCWR), owing to the substantial density variation experienced by the fluid during its passage through the cooling channels. Any supercritical fluid suffers drastic variation in all thermophysical properties around the pseudocritical point, which is the primary reason for instigating dynamic instabilities in such channels. Present study aims towards thorough exploration of the same, while coupling the thermalhydraulic characteristics with related fuel rod dynamics and neutronics, through a reduced-order model. A lumped-parameter-based approach is adopted to get a simple, yet robust, mathematical framework. The entire flow region is divided into three zones, namely, a heavyfluid region, a light-fluid region and an intermediate heavy and light fluid mixture region.

Investigating the role of crystalline TiO2 Nanotubes on the Photoelectrochemical performance of gC 3N4/TiO2 Composites.

Sunlight driven photoelectrochemical (PEC) water splitting has garnered excessive attention as an eco-friendly technique to produce renewable hydrogen. Designing TiO2 based composites have evolved as an efficient strategy to extend the photoactivity of TiO2, inhibit their charge recombination and increase their stability. Owing to its well-matched energy bands, graphitic carbon nitride (gC 3N4) has emerged as an effective counterpart of TiO2. The present work reports the synthesis of gC3N4/TiO2 composites from a three-step process where bulk gC 3N4 was electrodeposited on separated TiO2 nanotubes from a constantly rotating organic suspension at a voltage of about~ 90 V for desired time. To explore the role of crystalline TiO2 nanotubes on the composite formation, gC 3N4 was similarly electrodeposited on amorphous separated nanotubes etched from Ti Foil to obtain gC 3N4/amorphous TiO2 nanotube