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Noam Lior - One of the best experts on this subject based on the ideXlab platform.

  • fuel allocation in a combined steam injected gas turbine and thermal seawater Desalination System
    Desalination, 2007
    Co-Authors: Yongqing Wang, Noam Lior
    Abstract:

    Fuel allocation in a combined steam-injected gas turbine (STIG) power generation and multi-effect thermal vapor compression (METVC) Desalination System is studied, using seven methods: (1) Products Energy Method, (2) Products Exergy Method, (3) Power-Generation-Favored Method, (4) Heat-Production-Favored Method, (5) Basic Exergetic Cost Theory, (6) Functional Approach and (7) Splitting Factor Method. The latter three are thermoeconomics-based. Two sample cases are calculated. The methods and results are compared and discussed. The main conclusions are: it is important to carefully choose suitable methods to perform fuel allocation in a dual purpose Desalination Systems (here a combined STIG-METVC System) since different methods produce very different results; The results obtained from Methods (1) and (5) are unreasonable, and those from Methods (3) and (4) set the range within which the fuel allocation values must reside; Although thermoeconomic methodologies are considered to be the most rational for cost attribution of multi-product Systems, false results could be reached if they are not suitably used; When sufficient information is unavailable for performing a thermoeconomic analysis, Method (2) can be taken as an approximation for fuel allocation, as well as for the distribution of fuel cost and combustion pollutant emission, between power and water in a STIG-METVC System. A recommended fuel allocation analysis procedure, based on this study and with some generality for other gas-turbine power plant dual purpose thermal Desalination Systems, was outlined.

  • performance analysis of combined humidified gas turbine power generation and multi effect thermal vapor compression Desalination Systems part 1 the Desalination unit and its combination with a steam injected gas turbine power System
    Desalination, 2006
    Co-Authors: Yongqing Wang, Noam Lior
    Abstract:

    Abstract Humidified gas turbines (HGT) have been identified as a promising way of producing power. The use of the steam-injected gas turbine (STIG) HGT cycle in a combined power and water Desalination System was analyzed using energy and exergy performance criteria. A brief description and rationale of the background of HGT cycles and dual-purpose power and water Systems is given. A thermal Desalination unit was modeled and analyzed, and the results led to the selection of a multi-effect thermal vapor compression (METVC) unit for producing fresh water from seawater for both general use and humidification; then the performance of a STIG-based combined System was investigated. The analysis performed improved the understanding of the combined STIG power and water Desalination process and of ways to improve and optimize it. Some specific conclusions are that: (1) a METVC Desalination System is preferred to a multieffect evaporation one when the pressure of the motive steam is high enough, >∼3 bar, to run a steam jet ejector; (2) the steam injection rate in the STIG cycle has a strong effect on water and power production, offering good flexibility for design and operation; (3) higher pressure ratios and higher steam injection rates in the STIG cycle increase power generation, but decrease water production rates, and higher turbine inlet temperatures increased both power and water production; (4) a distinct water production gain can be obtained by recovering the stack gas energy. The results indicate that such dual-purpose Systems have good synergy, not only in fuel utilization, but also in operation and design flexibility.

  • thermal performance and exergy analysis of a thermal vapor compression Desalination System
    Energy Conversion and Management, 1996
    Co-Authors: Osman A. Hamed, Abdelqader M Zamamiri, Noam Lior
    Abstract:

    Abstract A thermodynamic analysis based on the first and second laws is conducted to evaluate the performance of a thermal vapor compression (TVC) Desalination System. The performance of the analytical model is compared with operational data obtained from tests performed on a four-effect, low temperature TVC Desalination System with performance ratios of 6.5–6.8, located in the U.A.E. The effect of the process variables on the plant's performance ratios is investigated. The exergy losses due to irreversibilities in different subSystems of the TVC System are evaluated and compared with those of the conventional multi-effect boiling (MEB) and mechanical vapor compression (MVC) Desalination Systems. The TVC System yields the least exergy destruction among the three Systems. SubSystem exergy analysis shows that most of the exergy destruction in the TVC System occurs in the first effect and in the thermo-compressor. Overall exergy losses can be significantly reduced by increasing the number of effects and the thermo-compressor entrainment ratio, and by decreasing the top brine and heating steam temperatures.

Joh H Lienhard - One of the best experts on this subject based on the ideXlab platform.

  • thermodynamic balancing of a fixed size two stage humidification dehumidification Desalination System
    Desalination, 2015
    Co-Authors: Karim M Chehayeb, Syed M Zubai, Prakash G Naraya, Joh H Lienhard
    Abstract:

    Abstract Humidification dehumidification (HDH) is a Desalination technology that has shown promise in small scale, decentralized applications. Previous studies on the multi-staging of HDH have used fixed-effectiveness models which do not explicitly account for transport processes in the components. However, to fully understand the effect of the variation of the mass flow rate ratio, it is necessary to implement heat and mass transfer models of the HDH System. In this paper, we model an HDH System consisting of a packed-bed humidifier and a multi-tray bubble column dehumidifier. We study the effect of the mass flow rate ratio on the performance of a fixed-size System, and we consider its effect on the entropy generation and the driving forces for heat and mass transfer. In addition, we define a generalized energy effectiveness for heat and mass exchangers. We also implement an air extraction/injection and simulate a wide range of operating conditions. We define criteria for the best System performance, and we study the effect of the distribution of available area between separate stages. We also present a thorough explanation of why the direction of extraction should always be from the humidifier to the dehumidifier.

  • treating produced water from hydraulic fracturing composition effects on scale formation and Desalination System selection
    Desalination, 2014
    Co-Authors: Gregory P Thiel, Joh H Lienhard
    Abstract:

    Abstract Produced water from unconventional gas and oil extraction may be hypersaline with uncommon combinations of dissolved ions. The aim of this analysis is to aid in the selection of produced water treatment technology by identifying the temperature, pH, and recovery ratio under which mineral solid formation from these produced waters is likely to occur. Eight samples of produced water from the Permian Basin and the Marcellus shale are discussed, with an average TDS of about 177 g/L but significant variability. Crystallization potential is quantified by the saturation index, and activity coefficients are calculated using the Pitzer model. The method is applied to estimate solid formation in the treatment of two design case samples: a 183 g/L sample representing the Permian Basin water and a 145 g/L sample representing the Marcellus. Without pretreatment, the most likely solids to form, defined by highest saturation index, are: CaCO3, FeCO3, MgCO3, MnCO3, SrCO3, BaSO4, CaSO4, MgSO4 and SrSO4. Some options for mitigating the formation of these scales are discussed. With appropriate pretreatment, it is estimated that recovery ratios of as high as 40–50% are achievable before NaCl, a major constituent, is likely to limit further concentration without significant crystallization.

  • use of multiple extractions and injections to thermodynamically balance the humidification dehumidification Desalination System
    International Journal of Heat and Mass Transfer, 2014
    Co-Authors: Karim M Chehayeb, Syed M Zubai, Prakash G Naraya, Joh H Lienhard
    Abstract:

    Abstract Humidification dehumidification (HDH) Desalination Systems are well suited for small scale, off-grid Desalination. These Systems are very robust and can tolerate a wide range of feed salinities, making them a good candidate for treating produced water from hydraulically fractured natural gas wells. A primary engineering challenge for these Systems is their high thermal energy consumption. In this study, we examine the use of multiple air extractions and injections to thermodynamically balance the HDH System, so as to make it more energy efficient. The effect of the number of extractions on several performance parameters is studied. In addition, we study the effect of the enthalpy pinch, which is a measure of performance for a heat and mass exchanger, on these performance parameters. Finally, we present results that can be used as guidelines in designing HDH Systems. These results include the identification of appropriate temperatures for the extracted/injected air streams, the division of the heat duty between stages, and the value of the mass flow rate ratio in each stage at various values of enthalpy pinch.

  • thermodynamic balancing of the humidification dehumidification Desalination System by mass extraction and injection
    International Journal of Heat and Mass Transfer, 2013
    Co-Authors: Prakash G Naraya, Syed M Zubai, Karim M Chehayeb, Rona K Mcgove, Gregory P Thiel, Joh H Lienhard
    Abstract:

    Abstract Humidification dehumidification (HDH) is a promising technology for small scale seawater Desalination and has received widespread attention in recent years. The biggest roadblock to commercialization of this technology is its relatively high energy consumption. In this paper, we propose thermodynamic balancing of the humidifier or the dehumidifier through mass extraction and injection as a potential means of reducing the energy consumption of these Systems. Balancing minimizes the entropy generation caused by imbalance in driving temperature and concentration differences. We outline a procedure to model the System, using on-design component variables, such that continuous or discrete extraction and/or injection of air from the humidifier to the dehumidifier or vice versa can be analyzed. We present an extraction profile (mass flow rate ratio versus non-dimensional position) in the dehumidifier and the humidifier for attaining close to complete thermodynamic reversibility in an HDH System with a 100% effective humidifier and dehumidifier. Further, we have examined in detail the effect of having finite-sized Systems, of balancing the humidifier versus the dehumidifier, and that of the number of extractions.

  • thermodynamic analysis of a reverse osmosis Desalination System using forward osmosis for energy recovery
    ASME 2012 International Mechanical Engineering Congress and Exposition, 2012
    Co-Authors: Leonardo David Anchik, Joh H Lienhard
    Abstract:

    Thermodynamic analysis is applied to assess the energy efficiency of hybrid Desalination cycles that are driven by simultaneous mixed inputs, including heat, electrical work, and chemical energy. A seawater Desalination cycle using work and a chemical input stream is analyzed using seawater properties. Two System models, a reversible separator and an irreversible component based model, are developed to find the least work required to operate the System with and without osmotic recovery. The component based model represents a proposed Desalination System which uses a reverse osmosis membrane for solute separation, a pressure exchanger for recovering a fraction of the flow work associated with the pressurized discharge brine, and a forward osmosis (FO) module for recovering some of the chemical energy contained within the concentrated discharge brine. The energy attained by the addition of the chemical input stream serves to lower the amount of electrical work required for operation. For this analysis, a wastewater stream of varying solute concentration, ranging from feed to brackish water salinity, is considered as the chemical stream. Unlike other models available in the literature, the FO exchanger is numerically simulated as a mass exchanger of given size which accounts for changing stream concentration, and consequently, stream-wise variations of osmotic pressure throughout the length of the unit. A parametric study is performed on the models by varying input conditions. For the reversible case it is found that significant work reductions can be made through the use of an energy recovery device when the inlet wastewater salinity used is less than the feed salinity of 35 g/kg. For the irreversible case with a typical recovery ratio and feed salinity, significant work reductions were only noted for a wastewater inlet of less than half of the feed salinity due to pump work losses. In the irreversible case, the use of a numerical model to simulate the FO exchanger resulted in a maximum work reduction when the pressure difference between streams was around one half of the osmotic pressure difference as opposed to the precise value of one half found in zero-dimensional exchanger models.Copyright © 2012 by ASME

Wang Yongqing - One of the best experts on this subject based on the ideXlab platform.

  • thermal performance analysis of single effect evaporation mechanical vapor compression seawater Desalination System
    Chemical Engineering(China), 2012
    Co-Authors: Wang Yongqing
    Abstract:

    As the only thermal Desalination process is run by mechanical energy,the mechanical vapor compression distillation System has advantages of higher quality of production water,higher energy efficiency,and lower thermal pollution to the environment.A thermal performance analysis of a single-effect evaporation mechanical vapor compression(SEE-MVC) seawater Desalination System was presented.The mathematic model was built,and a parametric analysis was performed.The results show that lower compression ratio,higher isentropic efficiency of compressor and lower evaporation temperature of seawater lead to lower power consumption and higher recovery rate of water production.The suitable range of evaporation temperature is 55-70 ℃,and that of compression ratio is 1.2-1.3.Taking the minimum specific work consumption as objective function,the main parameters of several cases were given for reference.

  • exergy analysis of a single effect evaporation mechanical vapor compression seawater Desalination System
    Journal of Jimei University, 2012
    Co-Authors: Wang Yongqing
    Abstract:

    An exergy analysis of a single-effect evaporation mechanical vapor compression(SEE-MVC) seawater Desalination System was given in this paper.A mathematic model of SEE-MVC was built,The calculation results from energetic balance and exergetic balance were compared.The exegetic performance of SEE-MVC,including the influence of the compression ratio,the isentropic efficiency of compressor and the evaporation temperature of seawater,was analyzed.The ways to improve the performance improvement of SEE-MVC were discussed.

M. A. Alghoul - One of the best experts on this subject based on the ideXlab platform.

  • design and experimental performance of brackish water reverse osmosis Desalination unit powered by 2 kw photovoltaic System
    Renewable Energy, 2016
    Co-Authors: P Poovanaesvaran, M H Mohammed, Assim Modhafar Fadhil, Ali F Muftah, Mahmud M Alkilani, M. A. Alghoul, Kamaruzzaman Sopian
    Abstract:

    Small-scale brackish water reverse osmosis (BWRO) Desalination units are not a major commercial success compared to its large-scale counterpart. Integrating renewable power Systems with small-scale units would theoretically aid in their deployment and subsequent commercial success. In fact, RO units are constructed using a modular approach; this would allow them to adapt to a renewable power supply. Small-scale PV-RO would be a promising form of Desalination System in remote areas, where BW is more common. The aim of this study is to quantify the effect of climatic-design-operation conditions on the performance and durability of a PV-BWRO Desalination System. A small-scale unit is designed, constructed, and tested for 6 months. The design was limited to a 2 kWp PV power System, five different membranes, a feed TDS of 2000 mg/l, and a permeate TDS of less than 50 mg/l. Data pertaining to solar radiation and temperature were subsequently analyzed to determine their respective influences on current and future operations of the unit. The results showed that the optimum RO load, membrane type, and design configuration were 600 W, (4″x40″ TW30-4040), and a two-stage configuration, respectively. The PV System was able to supply the load without any significant disturbances; while the RO unit showed stable levels of permeate flow and salinity. Operating the PV-BWRO System for 10 h during the day would produce 5.1 m3 of fresh water at a specific energy of 1.1 kWh/m3. It was confirmed that there are many hours of high temperatures during the operation of the PV module (exceeding 45 °C) and battery room conditions (exceeding 35 °C), both of which could negatively affect the power output and battery autonomy. This negative effect is compounded annually; therefore, optimizing thermal regulation of PV modules and battery bank room conditions is essential in maintaining excellent operating temperatures.

Yogi D Goswami - One of the best experts on this subject based on the ideXlab platform.

  • theoretical analysis of a water Desalination System using low grade solar heat
    Journal of Solar Energy Engineering-transactions of The Asme, 2004
    Co-Authors: S Alkharabsheh, Yogi D Goswami
    Abstract:

    Theoretical analysis of a solar Desalination System utilizing an innovative new concept, which uses low-grade solar heat, is presented. The System utilizes natural means of gravity and atmospheric pressure to create a vacuum, under which liquid can be evaporated at much lower temperatures and with less energy than conventional techniques. The uniqueness of the System is in the way natural forces are used to create vacuum conditions and its incorporation in a single System design where evaporation and condensation take place at appropriate locations without any energy input other than low grade heat. The System consists of solar heating System, an evaporator, a condenser, and injection, withdrawal, and discharge pipes. The effect of various operating conditions, namely, withdrawal rate, depth of water body, temperature of the heat source, and condenser temperature were studied. Numerical simulations show that the proposed System may have distillation efficiencies as high as 90% or more. Vacuum equivalent to 3.7 kPa (abs) or less can be created depending on the ambient temperature at which condensation will take place. @DOI: 10.1115/1.1669450#

  • analysis of an innovative water Desalination System using low grade solar heat
    Desalination, 2003
    Co-Authors: S Alkharabsheh, Yogi D Goswami
    Abstract:

    Abstract This paper presents a theoretical analysis and preliminary experimental results for an innovative water Desalination System using low-grade solar heat. The System utilizes natural means (gravity and atmospheric pressure) to create a vacuum under which water can be rapidly evaporated at much lower temperatures and with less energy than conventional techniques. The System consists of an evaporator connected to a condenser. The vapor produced in the evaporator is driven to the condenser where it condenses and is collected as a product. The effect of various operating conditions, namely, withdrawal rate, depth of water body in the evaporator, temperature of the heat source, and condenser temperature, on the System performance were studied. Numerical simulations and preliminary experimental results show that the performance of this System is superior to a flat basin solar still, and the output may be twice that of a flat-basin solar still for the same input. Vacuum equivalent to 4 kPa (abs) or less can be created depending on the ambient temperature at which condensation takes place.

  • theoretical analysis of a water Desalination System using low grade solar heat
    Solar Energy, 2003
    Co-Authors: S Alkharabsheh, Yogi D Goswami
    Abstract:

    Theoretical analysis of a solar Desalination System utilizing an innovative new concept, which uses low-grade solar heat, is presented. The System utilizes natural means of gravity and atmospheric pressure to create a vacuum, under which liquid can be evaporated at much lower temperatures and with less energy than conventional techniques. The uniqueness of the System is in the way natural forces are used to create vacuum conditions and its incorporation in a single System design where evaporation and condensation take place at appropriate locations without any energy input other than low grade heat. The System consists of solar heating System, an evaporator, a condenser, and injection, withdrawal, and discharge pipes. The effect of various operating conditions, namely, withdrawal rate, depth of water body, temperature of the heat source, and condenser temperature were studied. Numerical simulations show that the proposed System may have distillation efficiencies as high as 90% or more. Vacuum equivalent to 3.7 kPa (abs) or less can be created depending on the ambient temperature at which condensation will take place.Copyright © 2003 by ASME