Control performance evaluation of reverse osmosis desalination system based on model predictive control and PID controllers

Janghorban Esfahani, Iman,Ifaei, Pouya,Rshidi, Jouan,Yoo, ChangKyoo Balaban Publishers 2016 Desalination and Water Treatment Vol. No.

Exergetic Analysis of Power and Freshwater Cogeneration Systems

Iman Janghorban Esfahani,ChangKyoo Yoo 제어로봇시스템학회 2012 제어로봇시스템학회 국제학술대회 논문집 Vol.2012 No.10

This study proposes a systematic approach of energy and exergy analysis of reverse osmosis (RO) desalination system combined with the gas turbine power plant (GT). Three systems of RO for producing freshwater and a gas turbine for generating the power for the pumps and other equipments are compared in energy and exergy aspects. The first system mechanically couples RO with the power plant; while the second and third systems couples are mechanical as well as thermal, using a refrigeration cycle and compressor intercooler. Energy and exergy efficiencies and the rates of exergy destruction for all of the streams and components are identified. The third system with compressor intercooler showed the best performance among three systems, which increases energy and exergy efficiencies by 8.42% and 12.07%, respectively, compared with the first system as the base system.

Design of Hybrid Renewable Energy Systems with Battery/Hydrogen storage considering practical power losses: A MEPoPA (Modified Extended-Power Pinch Analysis)

Janghorban Esfahani, Iman,Ifaei, Pouya,Kim, Jinsoo,Yoo, ChangKyoo Elsevier 2016 ENERGY Vol.100 No.-

<P><B>Abstract</B></P> <P>EPoPA (Extended-Power Pinch Analysis) is a technique to integrate Hybrid Renewable Energy Systems with Battery/Hydrogen storage. Power losses of the storage components due to their inefficiency have not been considered in EPoPA as of yet. This study proposes the MEPoPA (Modified Extended-Power Pinch Analysis) to modify EPoPA to consider the power losses in Hydrogen Storage System components. The MEPoCC (Modified Extended-Power Composite Curve) and MEPoSCT (Modified Extended-Power Storage Cascade Table) are introduced as the MEPoPA graphical and numerical tools to determine the minimum targets of Required External AC (Alternating-Current) and DC (Direct-Current) Electricity Sources as well as the Hydrogen Storage System component sizes. The sensitivity analysis is conducted to investigate the effect of various Hydrogen Storage System components, such as the inverter, converters, Fuel Cell, Electrolyzer and rectifier efficiencies, on the Hydrogen Tank Electricity Capacity and the Required External AC and DC Electricity Sources. The graphical and numerical results of the MEPoPA obtained from a case study showed that the system designed by MEPoPA requires 62.19% more outsourced electricity than the system designed by EPoPA. This means that the integration potential of the Renewable Energy System with Battery/Hydrogen storage is decreased with an increase in the power losses of the storage system.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Construction of Modified Extended-Power Composite Curve. </LI> <LI> Construction of Modified Extended-Power Storage Cascade Table. </LI> <LI> Investigation of the various component efficiencies on the hydrogen tank capacity. </LI> <LI> Optimal systems comparison with and without power losses. </LI> <LI> Power losses decrease the integration potential of the battery/hydrogen system. </LI> </UL> </P>

Extended-power pinch analysis (EPoPA) for integration of renewable energy systems with battery/hydrogen storages

Janghorban Esfahani, Iman,Lee, SeungChul,Yoo, ChangKyoo Elsevier 2015 RENEWABLE ENERGY Vol.80 No.-

<P><B>Abstract</B></P> <P>An extended-power pinch analysis (EPoPA) is proposed as a means of extending the power pinch analysis (PoPA) for optimal design of renewable energy systems with battery and hydrogen storage (RES-BH). The EPoPA concept is based on the storage of wasted electricity that cannot be stored by the battery bank designed by PoPA. This energy is stored in the form of hydrogen and is discharged in the form of electricity when the external electricity source is needed. EPoPA graphical and numerical tools are introduced to determine the minimum required external electricity source, wasted electricity sources, and appropriate hydrogen storage system capacity of the RES-BH system during first and normal operation years. Furthermore, the integration of the RES-BH system with a diesel generator as a high reliable system is investigated in view point of economic. The optimal sizes of diesel generator and hydrogen storage system components, such as electrolyzer, fuel cell and hydrogen tank are obtained with the minimization of the total annual cost (TAC) of the system. The implementation results of the EPoPA tools on three possible case studies indicate that EPoPA, unlike other process integration methodologies such as PoPA, is able to optimally design RES-BH systems.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Proposing the extended-power pinch analysis (EPoPA) for renewable energy systems. </LI> <LI> Definition of extended-power composite curve (EPoCC) as the graphical approach. </LI> <LI> Proposition of extended-power cascade analysis as the numerical tool. </LI> <LI> Determination of the optimal hydrogen storage system and diesel generator sizes. </LI> <LI> Implementation of proposed EPoPA for three possible yearly case studies. </LI> </UL> </P>

Performance assessment and system optimization of a combined cycle power plant (CCPP) based on exergoeconomic and exergoenvironmental analyses

김민현,김동우,Iman Janghorban Esfahani,이승철,김민정,유창규 한국화학공학회 2017 Korean Journal of Chemical Engineering Vol.34 No.1

We propose a systematic approach for performance evaluation and improvement of a combined cycle power plant (CCPP). Exergoeconomic and exergoenvironmental analyses are used to assess CCPP performance and suggest improvement potentials in economic and environmental aspects, respectively. Economic and environmental impacts of individual system components are calculated by cost functions and life cycle assessments. Both analyses are based on a CCPP case study located in Turkey, which consists of two gas turbine cycles and a steam turbine cycle with two different pressure heat recovery units. The results of the exergoeconomic analysis indicate that the combustion chamber and condenser have a high performance improvement potential by increasing capital cost. Furthermore, the exergoenvironmental analysis shows that the exergy destruction of the steam turbine and combustion chamber and/or the capacity of heat recovery units must be reduced in order to improve environmental performance. This study demonstrates that combined exergoeconomic and exergoenvironmental analyses are useful for finding improvement potentials for system optimization by simultaneously evaluating economic and environmental impacts.

Localized indoor air quality monitoring for indoor pollutants’ healthy risk assessment using sub-principal component analysis driven model and engineering big data

시홍란,김민정,이승철,표세희,Iman Janghorban Esfahani,유창규 한국화학공학회 2015 Korean Journal of Chemical Engineering Vol.32 No.10

Indoor air quality (IAQ) in subway systems shows periodic dynamics due to the number of passengers, train schedules, and air pollutants accumulated in the system, which are considered as an engineering big data. We developed a new IAQ monitoring model using a sub-principal component analysis (sub-PCA) method to account for the periodic dynamics of the IAQ big data. In addition, the IAQ data in subway systems are different on the weekdays and weekend due to weekly effect, since the patterns of the number of passengers and their access time on the weekdays and weekend are different. Sub-PCA-based local monitoring was developed for separating the weekday and weekend environmental IAQ big data, respectively. The monitoring results for the test data at the Y-subway station clearly showed that the proposed method could analyze an environmental IAQ big data, improve the monitoring efficiency and greatly reduce the false alarm rate of the local on-line monitoring by comparison with the multi-way PCA.

Integration of reverse osmosis desalination with hybrid renewable energy sources and battery storage using electricity supply and demand-driven power pinch analysis

Li, Qian,Moya, Wladimir,Janghorban Esfahani, Iman,Rashidi, Jouan,Yoo, ChangKyoo Elsevier 2017 PROCESS SAFETY AND ENVIRONMENTAL PROTECTION Vol.111 No.-

<P><B>Abstract</B></P> <P>This study proposes the integration of reverse osmosis desalination with renewable energy sources and battery storage using energy-efficient power pinch analysis methodology for three different scenarios under an energy management strategy considering power supply and demand and power losses of the components in the system. The power cascade table and storage cascade table are introduced as numerical tools of power pinch analysis to determine the minimum outsourced electricity supply and available excess electricity for the next day, as well as the waste electricity, needed electricity, and the battery capacity for the system during a normal operation day. An optimization algorithm was applied based on the storage cascade table for a normal operation year to determine the optimal battery capacity for a dynamic freshwater demand to minimize the outsourced freshwater. Based on the energy management strategy, a case study in London, UK, showed scenario one as the best scenario with an optimum battery capacity of 1170.36kWh and freshwater production of 40,604.5m<SUP>3</SUP>, which can minimize 60,096.9m<SUP>3</SUP> of outsourced freshwater with a reasonable total annual cost of 503,159$/year.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Integrating an RES–RO under energy management strategy for three different scenarios. </LI> <LI> Constructing a power cascade table for an RES–BS–RO system considering power losses. </LI> <LI> Applying an optimization algorithm to optimize battery capacity with minimum freshwater production. </LI> <LI> Identifying the produced freshwater and its total annual cost with optimum battery capacity for a case study in London. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Water Pinch Analysis for a Reverse Osmosis Desalination Network to Increase Fresh Water Production

Srinivas Sahan Kolluri,Iman Janghorban Esfahani,ChangKyoo Yoo 대한환경공학회 2013 대한환경공학회 학술발표논문집 Vol.2013 No.6

Evaluation of multivariate statistical analyses for monitoring and prediction of processes in an seawater reverse osmosis desalination plant

Srinivas Sahan Kolluri,Iman Janghorban Esfahani,Prithvi Sai Nadh Garikiparthy,유창규 한국화학공학회 2015 Korean Journal of Chemical Engineering Vol.32 No.8

Our aim was to analyze, monitor, and predict the outcomes of processes in a full-scale seawater reverse osmosis (SWRO) desalination plant using multivariate statistical techniques. Multivariate analysis of variance (MANOVA) was used to investigate the performance and efficiencies of two SWRO processes, namely, pore controllable fiber filterreverse osmosis (PCF-SWRO) and sand filtration-ultra filtration-reverse osmosis (SF-UF-SWRO). Principal component analysis (PCA) was applied to monitor the two SWRO processes. PCA monitoring revealed that the SF-UF-SWRO process could be analyzed reliably with a low number of outliers and disturbances. Partial least squares (PLS) analysis was then conducted to predict which of the seven input parameters of feed flow rate, PCF/SF-UF filtrate flow rate, temperature of feed water, turbidity feed, pH, reverse osmosis (RO)flow rate, and pressure had a significant effect on the outcome variables of permeate flow rate and concentration. Root mean squared errors (RMSEs) of the PLS models for permeate flow rates were 31.5 and 28.6 for the PCF-SWRO process and SF-UF-SWRO process, respectively, while RMSEs of permeate concentrations were 350.44 and 289.4, respectively. These results indicate that the SF-UF-SWRO process can be modeled more accurately than the PCF-SWRO process, because the RMSE values of permeate flowrate and concentration obtained using a PLS regression model of the SF-UF-SWRO process were lower than those obtained for the PCF-SWRO process.

Assessment of environmental data quality and its effect on modelling error of full-scale plants with a closed-loop mass balancing

Lee, Seungchul,Rao, Sankara,Kim, MinJeong,Janghorban Esfahani, Iman,Yoo, ChangKyoo Informa UK (TaylorFrancis) 2015 Environmental Technology Vol.36 No.24

<P>Environmental plants are notorious for poor data quality and sensor reliability due to the hostile environment in which the measurement equipment has to function, where the measurements and flow rate equipment in plants must be mutually consistent. The aim of this study is to detect any error in the measured data in an environmental plant and reconcile the data with some gross errors by using a closed data reconciliation of mass balance and the Lagrange multiplier method. A data reconciliation method based on closed-loop mass balance is suggested in order to reduce or remove error within data and obtain reliable process data. The proposed method is applied to a full-scale plant to detect the gross error in measured data, investigate the effects of erroneous data on modelling errors and compare the modelling performances of the faulty data and reconciled data. The results show that the proposed method can efficiently detect any gross error in data, estimate the error-free data by a reconciliation method and enhance the modelling accuracy by using reconciled data. This study provides a simple way to incorporate prior knowledge of plant modelling of a closed-loop mass balancing to identify any gross error and reconcile the faulty measurements.</P>