Transient Analysis of Primary Feed Pump Trip for 700 MWe IPHWR

700 MWe Indian Pressurized Heavy Water Reactor (IPHWR) is a horizontal channel type reactor with two loops of Primary Heat Transport (PHTS) system. Three (two operating and one stand by) main boiler feed water pumps (BFP) supply feed water to Steam Generators (SGs). In the event of one of the running BFP trip, standby comes on line on auto. Transient analysis for this event is performed using in- house computer code ATMIKA.T .The transient has been initiated by tripping one of the pumps. Two cases are postulated: 1: BFP Trip and Standby BFP available on auto 2: BFP Trip and Standby pump not available. This paper provides timelines of following sequence of events which is important for operator’s action to maneuver the event, and the main findings of the study are: Following the tripping of one BFP, feed flow reduces and SGs level start falling. As SGs level fall, feed control valves open up in level control mode and system resistance in feed water circuit reduces. If the standby pump comes on auto, the SGs level recovers with a slight dip in level. The feed flow increases and settles down to normal value. Subsequently all the parameters converge to steady state value. Reactor continues to operate at 100% FP. In the event of main BFP trip without the availability of standby BFP, feed flow rate drops. SGs pressure rise slightly due to reduction in sub cooled feed flow and SGs level start to decrease. Reactor setback starts as SG level goes below set back limit. SG level continues to fall and reactor trips on SG Level very very low trip setting

Spatiotemporal Compound Wavelet Matrix Framework for Multiscale/Multiphysics Reactor Simulation: Case Study of a Heterogeneous Reaction/Diffusion System

We present a mathematical method for efficiently compounding information from different models of species diffusion from a chemically reactive boundary. The proposed method is intended to serve as a key component of a multiscale/ multiphysics framework for heterogeneous chemically reacting processes. An essential feature of the method is the merging of wavelet representations of the different models and their corresponding time and length scales. Up-and-downscaling of the information between the scales is accomplished by application of a compounding wavelet operator, which is assembled by establishing limited overlap in scales between the models. We show that the computational efficiency gain and potential error associated with the method depend on the extent of scale overlap and wavelet filtering used. We demonstrate the method for an example problem involving a two-dimensional chemically reactive boundary and first order reactions involving two species

Improvement in hot corrosion resistance of dissimilar alloy 825 and AISI 321 CO2-laser weldment by HVOF coating in aggressive salt environment at 900°C

This study investigated the hot corrosion performance of a dissimilar weldment of Ni-based superalloy and stainless steel joined by CO2-laser welding and improved by high-velocity oxy-fuel (HVOF) coating in a Na2SO4-60wt%V2O5 environment at 900°C. A dissimilar butt joint of AISI 321 and alloy 825 was fabricated by CO2-laser welding with low heat input after obtaining the optimum welding parameters by bead-on-plate trials. The metallurgical and mechanical properties of the laser weldment were evaluated. The tensile test results indicated the occurrence of fracture in the base metal AISI 321 side. The HVOF process was employed to coat Ni-20wt%Cr on the weldment. To evaluate the surface morphology of the corrosion products formed on the uncoated and Ni-20wt%Cr-coated weldments, scanning electron microscopy (SEM) analysis was performed. Energy-dispersive spectroscopy (EDS) was used to determine the different elements present on the surface scales. The existence of oxide phases on the weldments was determined by X-ray diffraction (XRD). The cross sections of the weldments were characterized by SEM with EDS line mapping analysis. The results indicated that the Ni-20wt%Cr-coated weldment exhibited superior hot corrosion resistance due to the development of Cr2O3 and NiCr2O4 protective oxide scales

A REAL TIME IMPLEMENTATION OF SMART AUTOMATION SYSTEM & DIGITAL CIRCULAR BOARD USING ANDROID, GSM, ARM-7 BASED TECHNOLOGIES

The project presents a digital circular board and a smart home automation system for hospitals, railway stations, bus stops, institutions & industries using Android, GSM Module and ARM-7. This idea provides the users with a simple, fast and reliable way to keep up important circulars in Liquid Crystal Display (LCD). The message can be sent through an android application by using proposed system to the GSM SIM900 module. Similarly, a smart automation system has been developed to control appliances like lights, fans, machines and digital boards in hospitals, railway stations, bus stops, institutions & industries These Appliance can be switched ON or OFF using the android application, the appliances can be controlled and notices or circulars can be put up in an LCD display from any location in the world. The project consists of a 32-bit ARM based microcontroller LPC2148 Development Board, GSM SIM900 module, an LCD, The proposed system can be used anywhere irrespective of the place of deployment provided mobile network connectivity is available. A GSM MOBILE based system is flexible, durable without any risk of getting hacked. Such a system has a low cost of installation and maintenance

A Cost Efficient Resource Provisioning Approach Using Virtual Machine Placement

Abstract-Cloud computing is evolving technology in which pool of resources are provided as services. Resource provisioning in cloud computing achieves systematic services on client registration using services present in cloud computing. In resources provisioning there is tremendous query formation for each client for utilizing their resources i.e. memory utilization, CPU utilization, and other resources are utilizing capabilities in cloud computing. For resource provisioning in cloud two popular mechanisms are reservation and on-demand plan services. According to the cost estimation process of the cloud services there is challenging task in optimization of capacity utilization in deploying virtual machine placement. In this paper, we suggest an optimal virtual machine placement algorithm to implement optimized resource provisioning operations. The proposed OVMP algorithm makes a decision process on cloud service provider with consistent stochastic integer programming to dedicate resources from cloud service providers. These service professional accepts the cloud computing services with resource provisioning with suitable services. Our experimental results show the minimized budgets with provisioning resources in emerging cloud computing environments

Deep Reinforcement Learning Based Control of a Grid Connected Inverter With LCL-Filter for Renewable Solar Applications

This research paper presents a novel approach to current control in Grid-Connected Inverters (GCI) using Deep Reinforcement Learning (DRL) based Twin Delayed Deep Deterministic Policy Gradient (TD3) method. The study focuses on addressing the limitations of traditional control techniques and state of the art techniques, particularly Proportional-Integral (PI) control and Model Predictive Control (MPC), by leveraging the adaptive and autonomous learning capabilities of DRL. The proposed novel modified TD3-based DRL method learns an optimal control policy directly from raw data, enabling the controller to adapt and improve its performance in real-time. The research includes a comprehensive analysis of the implementation and validation of the modified TD3-based DRL control in a grid-connected three phase three level Neutral Point Clamped (NPC) inverter system with Inductor-Capacitor-Inductor (LCL) filter. Real-time validation experiments are conducted to evaluate the control performance, power transfer capability in grid compliance. Furthermore, a detailed comparison is presented with experimentation, highlighting the advantages of the TD3-based DRL control over PI and MPC control techniques. Robustness checking is performed under various operating conditions, including parameter variations and dynamic conditions in the grid. The results analysis demonstrates that the TD3-based DRL control outperforms traditional PI control techniques in terms of static, dynamic response, and robustness. Additionally, The DRL based grid connected inverter current control method is validated in Renewable Energy Source (RES) solar PV grid integration application

New insights on recovery and early recrystallization of ferrite-pearlite banded cold rolled high strength steels by high speed nanoindentation mapping

This work unravels structure-property correlations at the micrometer length scale during recovery and early recrystallization of a cold rolled high strength steel comprised of ferrite and pearlite. High resolution nano-indention mapping is used to measure the hardness of ferrite, pearlite and the transition zone between them, which correlates well with the local microstructure obtained from scanning and transmission electron microscopy. A clustering algorithm is used to determine the properties of the constituent microstructural features. The variation in the hardness of the phases with annealing temperature agrees well with the dislocation activity observed using Transmission Electron Microscopy (TEM) and a simple mechanism to reconcile the observations is presented. © 2020 Acta Materialia Inc