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.

A highly efficient combined multi-effect evaporation-absorption heat pump and vapor-compression refrigeration part 2: Thermoeconomic and flexibility analysis

Janghorban Esfahani, I.,Yoo, C. Pergamon Press 2014 ENERGY Vol.75 No.-

This paper continues Part 1 of our study and develops a thermoeconomic model of the system with low and high pressure compressors. The thermoeconomic model was used to assess the unit cost of the fresh water and cooling and to evaluate the flexibility of the system for fuel allocation from different electricity and heat energy sources. A parametric analysis was carried out to investigate the effects of the RR (refrigerant flow-rate ratio) from the high pressure compressor to the low pressure compressor of the VCR (vapor compression refrigeration) system, the price of steam, and the price of electricity on the product cost rate and the exergy efficiency of the system. The results showed that the system with two compressors had high flexibility to allocate the different energy sources when the availability of the sources was limited for a given value of fresh water and cooling production.

A Cost Approach for Optimization of a Combined Power and Thermal Desalination System through Exergy and Environmental Analysis

Esfahani, I. Janghorban,Kim, J. T.,Yoo, C. K. American Chemical Society 2013 INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH - Vol.52 No.32

<P>In this Article, a systematic approach of cost analysis and optimization for combining the multieffect thermal vapor compression (METVC) desalination system with the gas turbine power plant (GT) was proposed on the basis of thermodynamic, economic, and environmental attributes. The total annual cost (TAC) of the combined system, including annual capital and operating costs, was modified to define an efficient cost objective function by adding the exergy destruction cost as a lost opportunity cost, and environmental emissions cost as a damage cost of the system to the operating cost. A parametric analysis was conducted to evaluate the effects of the key thermodynamic parameters for combining the GT and METVC systems, including the gas turbine inlet temperature (TIT), the HRSG outlet temperature (HOT), and the temperature difference between the effects of the METVC system (Δ<I>T</I><SUB>METVC</SUB>) on the modified total annual cost (MTAC). The parameter optimization was achieved using a genetic algorithm (GA) to find the optimal key thermodynamic parameters with minimization of the MTAC of the combined system. In addition, the methodology was applied to optimize the combining of a METVC desalination system with a GT power plant located in Mahshar, Iran. The optimization results indicated that the METVC systems with less than five effects cannot be combined with the current GT power plant because the combined systems cannot produce the power and fresh water requirements. Among the combined systems with more than four effects in the METVC system, the combined system with five effects in the METVC system was selected as the best system, which can produce 28 543 m<SUP>3</SUP>/day fresh water and 127 MW power, respectively, and reduce the NO<SUB><I>x</I></SUB> emission by 3.6% as compared to the current power plant.</P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ie401068c'>ACS Electronic Supporting Info</A></P>

A high efficient combined multi-effect evaporation-absorption heat pump and vapor-compression refrigeration part 1: Energy and economic modeling and analysis

Janghorban Esfahani, I.,Kang, Y.T.,Yoo, C. Pergamon Press 2014 ENERGY Vol.75 No.-

A novel combined system that combines a MEE-ABHP (multi-effect evaporation-absorption heat pump) with a VCR (vapor-compression refrigeration) cycle is proposed to simultaneously generate cooling and fresh water. In the combined system, the condenser of the VCR system is replaced by the MEE-ABHP system, where a portion of the fresh water produced in the last effect of the MEE (multi-effect evaporation) system is used as the refrigerant for the VCR system. In Part 1 of this two-part paper, model-based energy and cost analysis is developed to quantify and qualify the performance of the combined system. Parametric analysis is carried out to investigate the effects of absorber pressure (P<SUB>A</SUB>), temperature difference between effects of the MEE subsystem (ΔT<SUB>MEE</SUB>), temperature of the strong solution from absorber (T<SUB>1</SUB>), and temperature of the weak solution from generator (T<SUB>4</SUB>) on the performance of the system. In Part 2, thermo-economic and exergy analysis is conducted to evaluate the flexibility of the system for fuel allocation from different available power and heat energy sources. The results of Part 1 showed that the combined system can save 57.12%, 5.61%, and 25.6% in electric power, heat energy, and total annual cost compared to the stand-alone VCR and MEE-ABHP systems, respectively.

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>

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>

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.

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.

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>