Computing operation procedures for chemical plants using whole-plant simulation models

Calculations of PHEBUS FPT-1 are performed in the frame of CSNI International Standard Problem ISP-46. The objective of ISP-46 is to assess the capability of computer codes to provide an integral simulation of a severe accident in a Pressurised Water Reactor (PWR), from the initial stages of core heat-up to the behaviour of released fission products in the containment. The present calculations are performed using MELCOR, chosen as the main tool for assessment of Swiss nuclear plants by virtue of its whole-plant simulation capability, using modelling practices as similar as possible to those used in plant analyses. The calculations cover the bundle heat-up, degradation, the release, transport and retention of fission products and other materials, and the thermal-hydraulic and aerosol behaviour in the containment. Comparison between a best-estimate case and experiment demonstrates the code’s ability to capture most aspects of the sequence with fair to good accuracy. Uncertainties remain, particularly in regard to core degradation, and the chemistry and transport of fission products. Weaknesses of code models in these areas largely reflect limitations in current knowledge.

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Reducing Operating Cost With Anammox In Wastewater Treatment -- A Simulation Study

10.32920/ryerson.14662002 ◽

2021 ◽

Author(s):

Eliav J. Eini

Keyword(s):

Total Nitrogen ◽

Simulation Study ◽

Operating Cost ◽

Operational Strategies ◽

Reduce Operating Cost ◽

Start Up ◽

Whole Plant ◽

Plant Simulation ◽

Biological Nitrogen ◽

Anammox Process

A simulation study is presented to investigate the use of the Anammox process for removing nitrogen compounds from wastewater to reduce operating cost. The literature review of technologies for removal of Total Nitrogen includes an overview of the biological nitrogen cycle, the discovery of Anammox, bioreactor design, operational strategies, and start-up of full-scale processes. A facility of 656 MLD with influent loading of 35 mg/L as NH3-N and 250 mg/L as BOD is used as a basis of the simulation study. Preliminary bioreactor sizing calculations are developed for six configurations. Subsequently, eight whole-plant simulation cases are compared to demonstrate operational savings for removal of Total Nitrogen. For the sample facility, this is shown to be on the order of $460 to $680K/year while attaining 66-70% Total Nitrogen removal and reduced greenhouse gas emissions by 2 kt CO2/year. The project concludes with ideas about future development of the Anammox process.

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Developing Functional Relationships between Soil Waterlogging and Corn Shoot and Root Growth and Development

Plants ◽

10.3390/plants10102095 ◽

2021 ◽

Vol 10 (10) ◽

pp. 2095

Author(s):

Charles Hunt Walne ◽

K. Raja Reddy

Keyword(s):

Growth And Development ◽

Simulation Models ◽

Dry Weight ◽

Corn Hybrids ◽

Functional Relationships ◽

Soil Waterlogging ◽

Whole Plant ◽

Short And Long Term ◽

Corn Plants

Short- and long-term waterlogging conditions impact crop growth and development, preventing crops from reaching their true genetic potential. Two experiments were conducted using a pot-culture facility to better understand soil waterlogging impacts on corn growth and development. Two corn hybrids were grown in 2017 and 2018 under ambient sunlight and temperature conditions. Waterlogging durations of 0, 2, 4, 6, 8, 10, 12, and 14 days were imposed at the V2 growth stage. Morphological (growth and development) and pigment estimation data were collected 15 days after treatments were imposed, 23 days after sowing. As waterlogging was imposed, soil oxygen rapidly decreased until reaching zero in about 8–10 days; upon the termination of the treatments, the oxygen levels recovered to the level of the 0 days treatment within 2 days. Whole-plant dry weight declined as the waterlogging duration increased, and after 2 days of waterlogging, a 44% and 27% decline was observed in experiments 1 and 2, respectively. Leaf area and root volume showed an exponential decay similar to the leaf and root dry weight. Leaf number and plant height were the least sensitive measured parameters and decreased linearly in both experiments. Root forks were the most sensitive parameter after 14 days of waterlogging in both experiments, declining by 83% and 80% in experiments 1 and 2, respectively. The data from this study improve our understanding of how corn plants react to increasing durations of waterlogging. In addition, the functional relationships generated from this study could enhance current corn simulation models for field applications.

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Identification of production bottlenecks with the use of Plant Simulation software

Ekonomia i Zarzadzanie ◽

10.1515/emj-2016-0038 ◽

2016 ◽

Vol 8 (4) ◽

pp. 103-112 ◽

Cited By ~ 8

Author(s):

Mateusz Kikolski

Keyword(s):

Computer Simulation ◽

Production Capacity ◽

Simulation Models ◽

Simulation Software ◽

Computer Assisted ◽

Problem Analysis ◽

Production Lines ◽

Major Objective ◽

Plant Simulation ◽

Research Show

Abstract The problem of bottlenecks is a key issue in optimising and increasing the efficiency of manufacturing processes. Detecting and analysing bottlenecks is one of the basic constraints to the contemporary production enterprises. The enterprises should not ignore problems that significantly influence the efficiency of the processes. People responsible for the proper course of production try to devise methods to eliminate bottlenecks and the waiting time at the production line. The possibilities of production lines are limited by the throughput of bottlenecks that disturb the smoothness of the processes. The presented results of the experimental research show the possibilities of a computer simulation as a method for analysing problems connected with limiting the production capacity. A computer-assisted simulation allows for studying issues of various complexities that could be too work-consuming or impossible while using classic analytical methods. The article presents the results of the computer model analysis that involved the functioning of machinery within a chosen technological line of an enterprise from a sanitary sector. The major objective of the paper is to identify the possibility of applying selected simulation tool while analysing production bottlenecks. An additional purpose is to illustrate the subjects of production bottlenecks and creating simulation models. The problem analysis involved the application of the software Tecnomatix Plant Simulation by Siemens. The basic methods of research used in the study were literature studies and computer simulation.

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Automatic derivation of qualitative plant simulation models from legacy piping and instrumentation diagrams

Computers & Chemical Engineering ◽

10.1016/j.compchemeng.2016.04.040 ◽

2016 ◽

Vol 92 ◽

pp. 112-132 ◽

Cited By ~ 25

Author(s):

Esteban Arroyo ◽

Mario Hoernicke ◽

Pablo Rodríguez ◽

Alexander Fay

Keyword(s):

Simulation Models ◽

Plant Simulation

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Development and Use of Whole Plant Simulation Modeling as a Process Control Tool for Operating Enhanced Nutrient Removal Facilities

Proceedings of the Water Environment Federation ◽

10.2175/193864709793901752 ◽

2009 ◽

Vol 2009 (4) ◽

pp. 666-695

Author(s):

Thor Young ◽

John V. Stullken ◽

Dipankar Sen ◽

Doug Abbott

Keyword(s):

Process Control ◽

Nutrient Removal ◽

Simulation Modeling ◽

Whole Plant ◽

Plant Simulation ◽

Control Tool

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Coupled Gas-Exchange Model for C4 Leaves Comparing Stomatal Conductance Models

Plants ◽

10.3390/plants9101358 ◽

2020 ◽

Vol 9 (10) ◽

pp. 1358

Author(s):

Kyungdahm Yun ◽

Dennis Timlin ◽

Soo-Hyung Kim

Keyword(s):

Stomatal Conductance ◽

Gas Exchange ◽

Leaf Gas Exchange ◽

Water Status ◽

Simulation Models ◽

Exchange Model ◽

Modeling Framework ◽

Wide Range ◽

Plant Simulation ◽

Gas Exchange Model

Plant simulation models are abstractions of plant physiological processes that are useful for investigating the responses of plants to changes in the environment. Because photosynthesis and transpiration are fundamental processes that drive plant growth and water relations, a leaf gas-exchange model that couples their interdependent relationship through stomatal control is a prerequisite for explanatory plant simulation models. Here, we present a coupled gas-exchange model for C4 leaves incorporating two widely used stomatal conductance submodels: Ball–Berry and Medlyn models. The output variables of the model includes steady-state values of CO2 assimilation rate, transpiration rate, stomatal conductance, leaf temperature, internal CO2 concentrations, and other leaf gas-exchange attributes in response to light, temperature, CO2, humidity, leaf nitrogen, and leaf water status. We test the model behavior and sensitivity, and discuss its applications and limitations. The model was implemented in Julia programming language using a novel modeling framework. Our testing and analyses indicate that the model behavior is reasonably sensitive and reliable in a wide range of environmental conditions. The behavior of the two model variants differing in stomatal conductance submodels deviated substantially from each other in low humidity conditions. The model was capable of replicating the behavior of transgenic C4 leaves under moderate temperatures as found in the literature. The coupled model, however, underestimated stomatal conductance in very high temperatures. This is likely an inherent limitation of the coupling approaches using Ball–Berry type models in which photosynthesis and stomatal conductance are recursively linked as an input of the other.

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