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Sample records for recirculated cooling systems

  1. Preoperational test report, recirculation condenser cooling systems

    International Nuclear Information System (INIS)

    Clifton, F.T.

    1997-01-01

    This represents a preoperational test report for Recirculation Condenser Systems, Project W-030. Project W-030 provides a ventilation upgrade for the four Aging Waste Facility tanks. The four system provide condenser cooling water for vapor space cooling of tanks AY1O1, AY102, AZ1O1, AZ102. Each system consists of a valved piping loop, a pair of redundant recirculation pumps, a closed-loop evaporative cooling tower, and supporting instrumentation; equipment is located outside the farm on concrete slabs. Piping is routed to the each ventilation condenser inside the farm via below-grade concrete trenches. The tests verify correct system operation and correct indications displayed by the central Monitor and Control System

  2. Preoperational test report, recirculation condenser cooling systems

    Energy Technology Data Exchange (ETDEWEB)

    Clifton, F.T.

    1997-11-04

    This represents a preoperational test report for Recirculation Condenser Systems, Project W-030. Project W-030 provides a ventilation upgrade for the four Aging Waste Facility tanks. The four system provide condenser cooling water for vapor space cooling of tanks AY1O1, AY102, AZ1O1, AZ102. Each system consists of a valved piping loop, a pair of redundant recirculation pumps, a closed-loop evaporative cooling tower, and supporting instrumentation; equipment is located outside the farm on concrete slabs. Piping is routed to the each ventilation condenser inside the farm via below-grade concrete trenches. The tests verify correct system operation and correct indications displayed by the central Monitor and Control System.

  3. Cernavoda unit2 recirculated cooling water system transient analysis

    International Nuclear Information System (INIS)

    Nita, I. P.; Pancef, R.

    2015-01-01

    The paper is an approach to calculate the response of Cernavoda NPP Unit 2 RCW System to transient regimes during normal and abnormal regimes. Then one started to analyse the system response to reactor trip on class III and IV of power, LOCA on class IV of power, LOCA on class III power, LOIA on class IV of power, and LOIA on class III power. Moreover, one analysed the system transient due to requirement of changeover of a RCW operating pump, planned and unplanned changeover. This is the first transient approach to this system that took in consideration all building of the system, obtaining a very large system model, with over 900 pipe, 4 pumps, 50 consumers, 21 control valves. The changeover procedure was required to be analysed in order to change the nominal operating mode for Unit 2, from current 2 pumps in operation to 3 pump operations during summer operating mode. (authors)

  4. An implantable centrifugal blood pump with a recirculating purge system (Cool-Seal system).

    Science.gov (United States)

    Yamazaki, K; Litwak, P; Tagusari, O; Mori, T; Kono, K; Kameneva, M; Watach, M; Gordon, L; Miyagishima, M; Tomioka, J; Umezu, M; Outa, E; Antaki, J F; Kormos, R L; Koyanagi, H; Griffith, B P

    1998-06-01

    A compact centrifugal blood pump has been developed as an implantable left ventricular assist system. The impeller diameter is 40 mm, and pump dimensions are 55 x 64 mm. This first prototype, fabricated from titanium alloy, resulted in a pump weight of 400 g including a brushless DC motor. The weight of a second prototype pump was reduced to 280 g. The entire blood contacting surface is coated with diamond like carbon (DLC) to improve blood compatibility. Flow rates of over 7 L/min against 100 mm Hg pressure at 2,500 rpm with 9 W total power consumption have been measured. A newly designed mechanical seal with a recirculating purge system (Cool-Seal) is used for the shaft seal. In this seal system, the seal temperature is kept under 40 degrees C to prevent heat denaturation of blood proteins. Purge fluid also cools the pump motor coil and journal bearing. Purge fluid is continuously purified and sterilized by an ultrafiltration unit which is incorporated in the paracorporeal drive console. In vitro experiments with bovine blood demonstrated an acceptably low hemolysis rate (normalized index of hemolysis = 0.005 +/- 0.002 g/100 L). In vivo experiments are currently ongoing using calves. Via left thoracotomy, left ventricular (LV) apex descending aorta bypass was performed utilizing an expanded polytetrafluoroethylene (ePTFE) vascular graft with the pump placed in the left thoracic cavity. In 2 in vivo experiments, the pump flow rate was maintained at 5-9 L/min, and pump power consumption remained stable at 9-10 W. All plasma free Hb levels were measured at less than 15 mg/dl. The seal system has demonstrated good seal capability with negligible purge fluid consumption (<0.5 ml/day). In both calves, the pumps demonstrated trouble free continuous function over 6 month (200 days and 222 days).

  5. Air-cooled recirculation cooling systems. Technical and economic comparison; Luftgekuehlte Rueckkuehlsysteme. Technisch wirtschaftlicher Vergleich

    Energy Technology Data Exchange (ETDEWEB)

    Dierks, G. [Fa. Jaeggi/Guentner (Schweiz) AG, Trimbach (Switzerland)

    2000-03-01

    There are several air-cooled forced-circulation cooling systems for heat removal from refrigeration systems. Optimum solutions should not be selected on the basis of the cost factor alone; an integrative approach should be used instead. An exemplary investigation is presented. [German] Fuer die Waermeabfuhr aus kaeltetechnischen Anlagen stehen verschiedene luftgekuehlte, zwangsbelueftete Rueckkuehlsysteme zur Verfuegung. Die Auswahl des Systems ist oft von kurzfristigem Kostendenken gepraegt, was in technischer und wirtschaftlicher Hinsicht aber nicht immer der optimalen Loesung entspricht. Erst die genauere Kenntnis der verschiedenen Systeme und eine ganzheitliche Betrachtungsweise ermoeglichen die optimale Wahl fuer den einzelnen Fall. Die hier praesentierte Untersuchung wird anhand eines konkreten Falls dargestellt, wobei Preise und technische Produktdaten auf realen Anfragen beruhen. Der Autor ist um objetive Bewertung bemueht, der Leser moege aber selbst urteilen. (orig./AKF)

  6. Reliability problems in the recirculated cooling water system at Cernavoda NPP and corrective maintenance operations adopted

    International Nuclear Information System (INIS)

    Bucur, Ionel; Metes, Mircea

    2002-01-01

    Between February 18 and March 5, 2002 the Unit 1 of Cernavoda NPP was shutdown in an un-planned outage necessary to repair a crack on the piping of the Recirculated Cooling Water System. The large pipe diameter and the requirement of maintaining the system in operation during the outage, imposed a special technology for fixing the leak (isolation of the line with ice plugs). The paper presents information about the performed repair work. After repair operations the failed duct was checked by non-destructive methods and the results were submitted and approved by regulation authorities. The repair was considered successfully completed and the Unit restarted on March 5, 2002 at 0.57 am when the electric generator was switched on in parallel to the national electric power system. (authors)

  7. Liquid Hydrogen Recirculation System for Forced Flow Cooling Test of Superconducting Conductors

    Science.gov (United States)

    Shirai, Y.; Kainuma, T.; Shigeta, H.; Shiotsu, M.; Tatsumoto, H.; Naruo, Y.; Kobayashi, H.; Nonaka, S.; Inatani, Y.; Yoshinaga, S.

    2017-12-01

    The knowledge of forced flow heat transfer characteristics of liquid hydrogen (LH2) is important and necessary for design and cooling analysis of high critical temperature superconducting devices. However, there are few test facilities available for LH2 forced flow cooling for superconductors. A test system to provide a LH2 forced flow (∼10 m/s) of a short period (less than 100 s) has been developed. The test system was composed of two LH2 tanks connected by a transfer line with a controllable valve, in which the forced flow rate and its period were limited by the storage capacity of tanks. In this paper, a liquid hydrogen recirculation system, which was designed and fabricated in order to study characteristics of superconducting cables in a stable forced flow of liquid hydrogen for longer period, was described. This LH2 loop system consists of a centrifugal pump with dynamic gas bearings, a heat exchanger which is immersed in a liquid hydrogen tank, and a buffer tank where a test section (superconducting wires or cables) is set. The buffer tank has LHe cooled superconducting magnet which can produce an external magnetic field (up to 7T) at the test section. A performance test was conducted. The maximum flow rate was 43.7 g/s. The lowest temperature was 22.5 K. It was confirmed that the liquid hydrogen can stably circulate for 7 hours.

  8. Control of biological growth in recirculating cooling systems using treated secondary effluent as makeup water with monochloramine.

    Science.gov (United States)

    Chien, Shih-Hsiang; Chowdhury, Indranil; Hsieh, Ming-Kai; Li, Heng; Dzombak, David A; Vidic, Radisav D

    2012-12-01

    Secondary-treated municipal wastewater, an abundant and widely distributed impaired water source, is a promising alternative water source for thermoelectric power plant cooling. However, excessive biological growth is a major challenge associated with wastewater reuse in cooling systems as it can interfere with normal system operation as well as enhance corrosion and scaling problems. Furthermore, possible emission of biological aerosols (e.g., Legionella pneumophila) with the cooling tower drift can lead to public health concerns within the zone of aerosol deposition. In this study, the effectiveness of pre-formed and in-situ-formed monochloramine was evaluated for its ability to control biological growth in recirculating cooling systems using secondary-treated municipal wastewater as the only makeup water source. Bench-scale studies were compared with pilot-scale studies for their ability to predict system behavior under realistic process conditions. Effectiveness of the continuous addition of pre-formed monochloramine and monochloramine formed in-situ through the reaction of free chlorine with ammonia in the incoming water was evaluated in terms of biocide residual and its ability to control both planktonic and sessile microbial populations. Results revealed that monochloramine can effectively control biofouling in cooling systems employing secondary-treated municipal wastewater and has advantages relative to use of free chlorine, but that bench-scale studies seriously underestimate biocide dose and residual requirements for proper control of biological growth in full-scale systems. Pre-formed monochloramine offered longer residence time and more reliable performance than in-situ-formed monochloramine due to highly variable ammonia concentration in the recirculating water caused by ammonia stripping in the cooling tower. Pilot-scale tests revealed that much lower dosing rate was required to maintain similar total chlorine residual when pre-formed monochloramine

  9. Recirculating cooling water solute depletion models

    International Nuclear Information System (INIS)

    Price, W.T.

    1990-01-01

    Chromates have been used for years to inhibit copper corrosion in the plant Recirculating Cooling Water (RCW) system. However, chromates have become an environmental problem in recent years both in the chromate removal plant (X-616) operation and from cooling tower drift. In response to this concern, PORTS is replacing chromates with Betz Dianodic II, a combination of phosphates, BZT, and a dispersant. This changeover started with the X-326 system in 1989. In order to control chemical concentrations in X-326 and in systems linked to it, we needed to be able to predict solute concentrations in advance of the changeover. Failure to predict and control these concentrations can result in wasted chemicals, equipment fouling, or increased corrosion. Consequently, Systems Analysis developed two solute concentration models. The first simulation represents the X-326 RCW system by itself; and models the depletion of a solute once the feed has stopped. The second simulation represents the X-326, X-330, and the X-333 systems linked together by blowdown. This second simulation represents the concentration of a solute in all three systems simultaneously. 4 figs

  10. Water supply rates for recirculating evaporative cooling systems in poultry housing

    Science.gov (United States)

    Evaporative cooling (EC) is an important tool to reduce heat stress in animal housing systems. Expansion of ventilation capacity in tunnel ventilated poultry facilities has resulted in increased water demand for EC systems. As water resources become more limited and costly, proper planning and des...

  11. Towards a Better Control of Chemicals Dosing in Condenser Open-Recirculating Cooling Systems Through the Use of Modelling

    International Nuclear Information System (INIS)

    Lambert, Philippa; Lepine, Gaelle; Rapenne, Sophie; Demay, Eric; Jardin, Audrey; Shakourzadeh, Khalil; Alos-Ramos, Olga

    2012-09-01

    The main issue of condenser open recirculating cooling systems remains scaling. This can have high economic consequences due to a loss of thermal exchange, an increase of maintenance costs and potentially plant shutdown. To tackle this problem, EDF is currently designing new chemicals' dosing equipment for anti-scalants or acid. To optimise treatment cost and limit the chemicals' environmental impact, dosing and control systems should be efficient enough to add only the required quantity to prevent scaling without overdosing. CooliSS C , a model developed for simulating the water chemistry of open recirculating cooling systems, can be used to adjust acid dosage and to pre-evaluate selected acid control systems. In circuits with no current treatment, where the scaling situation is being monitored, CooliSS C is a useful tool in predicting scaling potential and could even be used to predict the expected quantity of deposits. In the first case study, CooliSS ST, the static version of the model, was used to evaluate the sulfuric acid injection needs for Golfech nuclear power plant following a modification to the condenser cooling water circuit operating conditions. The results obtained via simulation were compared with manual calculations in order to demonstrate the accuracy of the software. In the second case study, CooliSS DX, the dynamic version of the CooliSS C model, was used to evaluate new acid control systems planned for Cruas nuclear power plant before the systems' commissioning. CooliSS DX predicts the scaling rate in the different parts of the cooling water system as a function of time. In fact, this version is able to calculate the variations of chemical composition along the circuit when operating conditions change (make-up quality, flow rates, evaporation rate, temperature...). A module was combined to CooliSS DX to evaluate acid control equipment. This module allows the initial calculation of the acid flow rate as a function of operating

  12. Use of Produced Water in Recirculated Cooling Systems at Power Generating Facilities

    Energy Technology Data Exchange (ETDEWEB)

    C. McGowin; M. DiFilippo; L. Weintraub

    2006-06-30

    Tree ring studies indicate that, for the greater part of the last three decades, New Mexico has been relatively 'wet' compared to the long-term historical norm. However, during the last several years, New Mexico has experienced a severe drought. Some researchers are predicting a return of very dry weather over the next 30 to 40 years. Concern over the drought has spurred interest in evaluating the use of otherwise unusable saline waters to supplement current fresh water supplies for power plant operation and cooling and other uses. The U.S. Department of Energy's National Energy Technology Laboratory sponsored three related assessments of water supplies in the San Juan Basin area of the four-corner intersection of Utah, Colorado, Arizona, and New Mexico. These were (1) an assessment of using water produced with oil and gas as a supplemental supply for the San Juan Generating Station (SJGS); (2) a field evaluation of the wet-surface air cooling (WSAC) system at SJGS; and (3) the development of a ZeroNet systems analysis module and an application of the Watershed Risk Management Framework (WARMF) to evaluate a range of water shortage management plans. The study of the possible use of produced water at SJGS showed that produce water must be treated to justify its use in any reasonable quantity at SJGS. The study identified produced water volume and quality, the infrastructure needed to deliver it to SJGS, treatment requirements, and delivery and treatment economics. A number of produced water treatment alternatives that use off-the-shelf technology were evaluated along with the equipment needed for water treatment at SJGS. Wet surface air-cooling (WSAC) technology was tested at the San Juan Generating Station (SJGS) to determine its capacity to cool power plant circulating water using degraded water. WSAC is a commercial cooling technology and has been used for many years to cool and/or condense process fluids. The purpose of the pilot test was to

  13. The radon daughter radiation hazard in controlled recirculation systems

    International Nuclear Information System (INIS)

    Rolle, R.; Burton, R.C.

    1987-01-01

    In deep South African gold mines, controlled recirculation systems with air cooling are being used to an increasing extent to improve the thermal environment. Recirculation causes some air to reside in the working area for a longer time than would have occurred without recirculation. Since radon daughters grow spontaneously from radon there is some concern that, with the extended residence time, the potential radiation hazard could increase to an unacceptable level. This paper describes the results obtained from a theoretical model of a controlled recirculation system. Guidelines for the design of recirculation systems to control the radon daughter radiation, and to keep it within acceptable limits are provided. 3 refs., 5 figs

  14. Recirculation system for nuclear reactors

    International Nuclear Information System (INIS)

    Braun, H. E.; Dollard, W. J.; Tower, S. N.

    1980-01-01

    A recirculation system for use in pressurized water nuclear reactors to increase the output temperature of the reactor coolant, thereby achieving a significant improvement in plant efficiency without exceeding current core design limits. A portion of the hot outlet coolant is recirculated to the inlets of the peripheral fuel assemblies which operate at relatively low power levels. The outlet temperature from these peripheral fuel assemblies is increased to a temperature above that of the average core outlet. The recirculation system uses external pumps and introduces the hot recirculation coolant to the free space between the core barrel and the core baffle, where it flows downward and inward to the inlets of the peripheral fuel assemblies. In the unlikely event of a loss of coolant accident, the recirculation system flow path through the free space and to the inlets of the fuel assemblies is utilized for the injection of emergency coolant to the lower vessel and core. During emergency coolant injection, the emergency coolant is prevented from bypassing the core through the recirculation system by check valves inserted into the recirculation system piping

  15. Recirculation nursery systems for bivalves

    NARCIS (Netherlands)

    Kamermans, P.; Blanco Garcia, A.; Joaquim, Sandra; Matias, Domitilia; Magnesen, Thorolf; Nicolas, J.; Petten, Bruno; Robert, Rene

    2016-01-01

    n order to increase production of bivalves in hatcheries and nurseries, the development of new technology and its integration into commercial bivalve hatcheries is important. Recirculation aquaculture systems (RASs) have several advantages: high densities of the species can be cultured resulting in

  16. Preoperational test report, recirculation ventilation systems

    International Nuclear Information System (INIS)

    Clifton, F.T.

    1997-01-01

    This represents a preoperational test report for Recirculation Ventilation Systems, Project W-030. Project W-030 provides a ventilation upgrade for the four Aging Waste Facility tanks. The system provides vapor space cooling of tanks AY1O1, AY102, AZ1O1, AZ102 and supports the ability to exhaust air from each tank. Each system consists of a valved piping loop, a fan, condenser, and moisture separator; equipment is located inside each respective tank farm in its own hardened building. The tests verify correct system operation and correct indications displayed by the central Monitor and Control System

  17. Preoperational test report, recirculation ventilation systems

    Energy Technology Data Exchange (ETDEWEB)

    Clifton, F.T.

    1997-11-11

    This represents a preoperational test report for Recirculation Ventilation Systems, Project W-030. Project W-030 provides a ventilation upgrade for the four Aging Waste Facility tanks. The system provides vapor space cooling of tanks AY1O1, AY102, AZ1O1, AZ102 and supports the ability to exhaust air from each tank. Each system consists of a valved piping loop, a fan, condenser, and moisture separator; equipment is located inside each respective tank farm in its own hardened building. The tests verify correct system operation and correct indications displayed by the central Monitor and Control System.

  18. Effect of emergency core cooling system flow reduction on channel temperature during recirculation phase of large break loss-of-coolant accident at Wolsong unit 1

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Seon Oh; Cho, Yong Jin [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of); Kim, Sung Joong [Dept. of Nuclear Engineering, Hanyang University, Seoul (Korea, Republic of)

    2017-08-15

    The feasibility of cooling in a pressurized heavy water reactor after a large break loss-of-coolant accident has been analyzed using Multidimensional Analysis of Reactor Safety-KINS Standard code during the recirculation phase. Through evaluation of sensitivity of the fuel channel temperature to various effective recirculation flow areas, it is determined that proper cooling of the fuel channels in the broken loop is feasible if the effective flow area remains above approximately 70% of the nominal flow area. When the flow area is reduced by more than approximately 25% of the nominal value, however, incipience of boiling is expected, after which the thermal integrity of the fuel channel can be threatened. In addition, if a dramatic reduction of the recirculation flow occurs, excursions and frequent fluctuations of temperature in the fuel channels are likely to be unavoidable, and thus damage to the fuel channels would be anticipated. To resolve this, emergency coolant supply through the newly installed external injection path can be used as one alternative means of cooling, enabling fuel channel integrity to be maintained and permanently preventing severe accident conditions. Thus, the external injection flow required to guarantee fuel channel coolability has been estimated.

  19. Effect of emergency core cooling system flow reduction on channel temperature during recirculation phase of large break loss-of-coolant accident at Wolsong unit 1

    Directory of Open Access Journals (Sweden)

    Seon Oh Yu

    2017-08-01

    Full Text Available The feasibility of cooling in a pressurized heavy water reactor after a large break loss-of-coolant accident has been analyzed using Multidimensional Analysis of Reactor Safety-KINS Standard code during the recirculation phase. Through evaluation of sensitivity of the fuel channel temperature to various effective recirculation flow areas, it is determined that proper cooling of the fuel channels in the broken loop is feasible if the effective flow area remains above approximately 70% of the nominal flow area. When the flow area is reduced by more than approximately 25% of the nominal value, however, incipience of boiling is expected, after which the thermal integrity of the fuel channel can be threatened. In addition, if a dramatic reduction of the recirculation flow occurs, excursions and frequent fluctuations of temperature in the fuel channels are likely to be unavoidable, and thus damage to the fuel channels would be anticipated. To resolve this, emergency coolant supply through the newly installed external injection path can be used as one alternative means of cooling, enabling fuel channel integrity to be maintained and permanently preventing severe accident conditions. Thus, the external injection flow required to guarantee fuel channel coolability has been estimated.

  20. Device for recirculation cooling of cooling water by natural or forced chaft

    Energy Technology Data Exchange (ETDEWEB)

    Ruehl, H; Honekamp, H; Katzmann, A

    1975-10-23

    The invention is concerned with a device for recirculation cooling of cooling water by natural or forced draft. Through a cascading system mounted on supporting columns at a vertical distance to ground level, cooling air is flowing in cross- or counterflow to the cooling water freely falling from the cascading system. The cooling water collecting zone below the cascading system has an absorption floor arranged nearly horizontal and/or inclined, with a cam-type profile on its upperside, which is bounded on its circumference by at least one cooling water release channel provided below its level and/or which is divided in the sense of a surface subdivision. By these means, a reduction of the amount of material required for the supporting columns and an increase of the stability of the columns is to be achieved. Furthermore, the deposition of mud is to be avoided as for as possible, and noise generation during operation is to be reduced considerably. For this purpose, the absorption floor may be made of material sound insulating and/or may be coated with such a material.

  1. BWR series pump recirculation system

    International Nuclear Information System (INIS)

    Dillmann, C.W.

    1992-01-01

    This patent describes a recirculation system for driving reactor coolant water contained in an annular downcomer defined between a boiling water reactor vessel and a reactor core spaced radially inwardly therefrom. It comprises a plurality of circumferentially spaced second pumps disposed in the downcomer, each including an inlet for receiving from the downcomer a portion of the coolant water as pump inlet flow, and an outlet for discharging the pump inlet flow pressurized in the second pump as pump outlet flow; and means for increasing pressure of the pump inlet flow at the pump inlet including a first pump disposed in series flow with the second pump for first receiving the pump inlet flow from the downcomer and discharging to the second pump inlet flow pressurized in the first pump

  2. Use of Treated Municipal Wastewater as Power Plant Cooling System Makeup Water: Tertiary Treatment versus Expanded Chemical Regimen for Recirculating Water Quality Management

    Energy Technology Data Exchange (ETDEWEB)

    David Dzombak; Radisav Vidic; Amy Landis

    2012-06-30

    Treated municipal wastewater is a common, widely available alternative source of cooling water for thermoelectric power plants across the U.S. However, the biodegradable organic matter, ammonia-nitrogen, carbonate and phosphates in the treated wastewater pose challenges with respect to enhanced biofouling, corrosion, and scaling, respectively. The overall objective of this study was to evaluate the benefits and life cycle costs of implementing tertiary treatment of secondary treated municipal wastewater prior to use in recirculating cooling systems. The study comprised bench- and pilot-scale experimental studies with three different tertiary treated municipal wastewaters, and life cycle costing and environmental analyses of various tertiary treatment schemes. Sustainability factors and metrics for reuse of treated wastewater in power plant cooling systems were also evaluated. The three tertiary treated wastewaters studied were: secondary treated municipal wastewater subjected to acid addition for pH control (MWW_pH); secondary treated municipal wastewater subjected to nitrification and sand filtration (MWW_NF); and secondary treated municipal wastewater subjected nitrification, sand filtration, and GAC adsorption (MWW_NFG). Tertiary treatment was determined to be essential to achieve appropriate corrosion, scaling, and biofouling control for use of secondary treated municipal wastewater in power plant cooling systems. The ability to control scaling, in particular, was found to be significantly enhanced with tertiary treated wastewater compared to secondary treated wastewater. MWW_pH treated water (adjustment to pH 7.8) was effective in reducing scale formation, but increased corrosion and the amount of biocide required to achieve appropriate biofouling control. Corrosion could be adequately controlled with tolytriazole addition (4-5 ppm TTA), however, which was the case for all of the tertiary treated waters. For MWW_NF treated water, the removal of ammonia by

  3. BWR recirculation pump diagnostic expert system

    International Nuclear Information System (INIS)

    Chiang, S.C.; Morimoto, C.N.; Torres, M.R.

    2004-01-01

    At General Electric (GE), an on-line expert system to support maintenance decisions for BWR recirculation pumps for nuclear power plants has been developed. This diagnostic expert system is an interactive on-line system that furnishes diagnostic information concerning BWR recirculation pump operational problems. It effectively provides the recirculation pump diagnostic expertise in the plant control room continuously 24 hours a day. The expert system is interfaced to an on-line monitoring system, which uses existing plant sensors to acquire non-safety related data in real time. The expert system correlates and evaluates process data and vibration data by applying expert rules to determine the condition of a BWR recirculation pump system by applying knowledge based rules. Any diagnosis will be automatically displayed, indicating which pump may have a problem, the category of the problem, and the degree of concern expressed by the validity index and color hierarchy. The rules incorporate the expert knowledge from various technical sources such as plant experience, engineering principles, and published reports. These rules are installed in IF-THEN formats and the resulting truth values are also expressed in fuzzy terms and a certainty factor called a validity index. This GE Recirculation Pump Expert System uses industry-standard software, hardware, and network access to provide flexible interfaces with other possible data acquisition systems. Gensym G2 Real-Time Expert System is used for the expert shell and provides the graphical user interface, knowledge base, and inference engine capabilities. (author)

  4. Production of cobia in recirculating systems

    Science.gov (United States)

    Only limited information exists with respect to rearing juvenile cobia Rachycentron canadum to stocker and marketable sizes using recirculating aquaculture systems (RAS). To investigate this topic, two rearing trials were conducted using commercial scale RAS. In Trial 1, juvenile cobia (29 g) we...

  5. Engineering systems designs for a recirculating heavy ion induction accelerator

    International Nuclear Information System (INIS)

    Newton, M.A.; Barnard, J.J.; Reginato, L.L.; Yu, S.S.

    1991-05-01

    Recirculating heavy ion induction accelerators are being investigated as possible drivers for heavy ion fusion. Part of this investigation has included the generation of a conceptual design for a recirculator system. This paper will describe the overall engineering conceptual design of this recirculator, including discussions of the dipole magnet system, the superconducting quadrupole system and the beam acceleration system. Major engineering issues, evaluation of feasibility, and cost tradeoffs of the complete recirculator system will be presented and discussed. 5 refs., 4 figs

  6. Re-circulating linac vacuum system

    International Nuclear Information System (INIS)

    Wells, Russell P.; Corlett, John N.; Zholents, Alexander A.

    2003-01-01

    The vacuum system for a proposed 2.5 GeV, 10ΜA recirculating linac synchrotron light source [1] is readily achievable with conventional vacuum hardware and established fabrication processes. Some of the difficult technical challenges associated with synchrotron light source storage rings are sidestepped by the relatively low beam current and short beam lifetime requirements of a re-circulating linac. This minimal lifetime requirement leads directly to relatively high limits on the background gas pressure through much of the facility. The 10ΜA average beam current produces very little synchrotron radiation induced gas desorption and thus the need for an ante-chamber in the vacuum chamber is eliminated. In the arc bend magnets, and the insertion devices, the vacuum chamber dimensions can be selected to balance the coherent synchrotron radiation and resistive wall wakefield effects, while maintaining the modest limits on the gas pressure and minimal outgassing

  7. Comparison of biocides for disinfection treatment of open recirculating cooling circuits

    International Nuclear Information System (INIS)

    Soreau, Sylvie; Prisset, Frederic; Carvajal, Nathalie

    2012-09-01

    Open recirculating cooling circuits of nuclear power plants are likely to face pathogenic proliferations like Legionella and amoebae (Naegleria fowleri). To reduce such risks, biocide treatments are usually implemented. However, the selection of a treatment is never easy due to the large size of the cooling circuits. Indeed, the range of treatment options is limited due to potential health or environmental impacts of chemicals in case of chemical treatments or because of the technical difficulties to implement treatment units appropriate to the size of the cooling circuits in case of physical treatments. In the aim of finding the best compromise between efficacy, nature and quantity of chemical releases and industrial feasibility, several biocide treatments were compared at lab and pilot scale using semi-industrial pilot plants simulating recirculating cooling circuit of a nuclear power plant. These pilots were fed with river water or pre-treated water (lime softening or clari-flocculation). They were equipped with materials and surfaces representative of those found on a full-scale plant. These pilots operated at summer temperatures favoring microbial growth. Three industrial biocides were compared: chlorine, monochloramine and chlorine dioxide. The results indicate that the transit in the cooling system strongly affects the consumption of biocides and therefore their efficacy, the quantity of biocide needed and chemical releases so that the ranking of treatments defined on the basis of laboratory tests can be strongly modified. The results show different areas of consumption along the process line depending on biocides and highlight the significant role of the cooling tower. The behavior of biocides in the different compartments of the circuit (cooling tower, condenser, basins) is described and the consequences on pathogenic micro-organisms removal in bio-films and on chemical releases are considered as function of the studied biocide. Moreover, the influence of

  8. Development of fluorocarbon evaporative cooling recirculators and controls for the ATLAS inner silicon tracker

    CERN Document Server

    Bayer, C; Bonneau, P; Bosteels, Michel; Burckhart, H J; Cragg, D; English, R; Hallewell, G D; Hallgren, Björn I; Ilie, S; Kersten, S; Kind, P; Langedrag, K; Lindsay, S; Merkel, M; Stapnes, Steinar; Thadome, J; Vacek, V

    2000-01-01

    We report on the development of evaporative fluorocarbon cooling recirculators and their control systems for the ATLAS inner silicon tracker. We have developed a prototype circulator using a dry, hermetic compressor with C/sub 3/F/sup 8/ refrigerant, and have prototyped the remote-control analog pneumatic links for the regulation of coolant mass flows and operating temperatures that will be necessary in the magnetic field and radiation environment around ATLAS. pressure and flow measurement and control use 150+ channels of standard ATLAS LMB ("Local Monitor Board") DAQ and DACs on a multi-drop CAN network administered through a BridgeVIEW user interface. A hardwired thermal interlock system has been developed to cut power to individual silicon modules should their temperatures exceed safe values. Highly satisfactory performance of the circulator under steady state, partial-load and transient conditions was seen, with proportional fluid flow tuned to varying circuit power. Future developments, including a 6 kW...

  9. Exhaust gas recirculation system for an internal combustion engine

    Science.gov (United States)

    Wu, Ko-Jen

    2013-05-21

    An exhaust gas recirculation system for an internal combustion engine comprises an exhaust driven turbocharger having a low pressure turbine outlet in fluid communication with an exhaust gas conduit. The turbocharger also includes a low pressure compressor intake and a high pressure compressor outlet in communication with an intake air conduit. An exhaust gas recirculation conduit fluidly communicates with the exhaust gas conduit to divert a portion of exhaust gas to a low pressure exhaust gas recirculation branch extending between the exhaust gas recirculation conduit and an engine intake system for delivery of exhaust gas thereto. A high pressure exhaust gas recirculation branch extends between the exhaust gas recirculation conduit and the compressor intake and delivers exhaust gas to the compressor for mixing with a compressed intake charge for delivery to the intake system.

  10. Recirculating ventilation system for radioactive laboratories

    International Nuclear Information System (INIS)

    Kotrappa, P.; Menon, V.B.; Dingankar, M.V.; Chandramoleshwar, K.; Bhargava, B.L.

    1980-01-01

    Radioactive laboratories designed to handle toxic substances such as plutonium are required to have ''once through'' ventilation scheme. This is an expensive proposition particularly when conditioned air is required. A recent approach is to have recirculatory system with exhausted air passing through absolute (HEPA) filters. This scheme not only drastically reduces capital costs but also substantially cuts down maintenance and running costs. Experiments emplyoing aerosol clearance techniques were conducted to specifically establish that this new scheme meets all the health physics safety stipulations laid down for such installations. It is shown that the ''once through'' system is three times more expensive compared to the recirculation system adopted in Purnima Laboratories. Further a saving of 70% is also achieved in running and operating costs. Therefore the new approach deserves serious consideration in future planning of similar projects, particularly in view of the fact that the considerable savings achievable both in terms of money and energy are without in any way compromising on safety. (auth.)

  11. Modelization of cooling system components

    Energy Technology Data Exchange (ETDEWEB)

    Copete, Monica; Ortega, Silvia; Vaquero, Jose Carlos; Cervantes, Eva [Westinghouse Electric (Spain)

    2010-07-01

    In the site evaluation study for licensing a new nuclear power facility, the criteria involved could be grouped in health and safety, environment, socio-economics, engineering and cost-related. These encompass different aspects such as geology, seismology, cooling system requirements, weather conditions, flooding, population, and so on. The selection of the cooling system is function of different parameters as the gross electrical output, energy consumption, available area for cooling system components, environmental conditions, water consumption, and others. Moreover, in recent years, extreme environmental conditions have been experienced and stringent water availability limits have affected water use permits. Therefore, modifications or alternatives of current cooling system designs and operation are required as well as analyses of the different possibilities of cooling systems to optimize energy production taking into account water consumption among other important variables. There are two basic cooling system configurations: - Once-through or Open-cycle; - Recirculating or Closed-cycle. In a once-through cooling system (or open-cycle), water from an external water sources passes through the steam cycle condenser and is then returned to the source at a higher temperature with some level of contaminants. To minimize the thermal impact to the water source, a cooling tower may be added in a once-through system to allow air cooling of the water (with associated losses on site due to evaporation) prior to returning the water to its source. This system has a high thermal efficiency, and its operating and capital costs are very low. So, from an economical point of view, the open-cycle is preferred to closed-cycle system, especially if there are no water limitations or environmental restrictions. In a recirculating system (or closed-cycle), cooling water exits the condenser, goes through a fixed heat sink, and is then returned to the condenser. This configuration

  12. Thermal-hydraulic analyses of the recirculated cooling water from cernavoda n.p.p. unit 1

    International Nuclear Information System (INIS)

    Pancef, R.; Anghel, N.; Nita, I. P.

    2013-01-01

    The paper presents the results from a very complex and large analysis performed for the Recirculated Cooling Water System. The analysis was required in order to increase the flow rate for moderator heat exchangers and introduction of a new consumer: urban heating. The system capability to supply with cooling agent all this consumers at all operating regimes from the design manual of the system had to be checked. One concluded that the required modification to the system had no influence in operating the system in all operating condition but there is an issue is regarding the necessity to recalculate the heat load from the moderator heater. The analysis was calibrated by using measurements from the plant, which have been obtained with ultrasonic flowmeters and local indicators. The analysis concludes that the system can change the requirements to the moderator heat exchangers and a new turbine building consumer (urban heating) can be introduced. (authors)

  13. Modern cooling systems in thermal power plants relieve environmental pollution. Pt. 2

    International Nuclear Information System (INIS)

    Brosche, D.

    1983-01-01

    Direct and indirect dry recirculation cooling, wet cooling tower, natural-draught wet cooling tower, combined cooling processes, hybrid cooling systems, cell cooling systems, auxiliary water preparation, cooling process design, afterheat removal in nuclear power plants, environmental effects, visible plumes as a function of weather conditions, environmental protection and energy supply assurance. (orig.) [de

  14. Freshwater Institute: Focused on improving recirculating aquaculture system technology

    Science.gov (United States)

    Recirculating aquaculture system (RAS) technologies help to overcome barriers to domestic aquaculture expansion and enhance the sustainability of the modern fish farming industry through reduction in environmental impacts. With RAS, fish farm expansion is no longer highly constrained by competition ...

  15. Cooling systems

    International Nuclear Information System (INIS)

    Coutant, C.C.

    1978-01-01

    Progress on the thermal effects project is reported with regard to physiology and distribution of Corbicula; power plant effects studies on burrowing mayfly populations; comparative thermal responses of largemouth bass from northern and southern populations; temperature selection by striped bass in Cherokee Reservoir; fish population studies; and predictive thermoregulation by fishes. Progress is also reported on the following; cause and ecological ramifications of threadfin shad impingement; entrainment project; aquaculture project; pathogenic amoeba project; and cooling tower drift project

  16. Investigation of induced recirculation during planned ventilation system maintenance

    Science.gov (United States)

    Pritchard, C.J.; Scott, D.F.; Noll, J.D.; Voss, B.; Leonis, D.

    2015-01-01

    The Office of Mine Safety and Health Research (OMSHR) investigated ways to increase mine airflow to underground metal/nonmetal (M/NM) mine working areas to improve miners’ health and safety. One of those areas is controlled recirculation. Because the quantity of mine air often cannot be increased, reusing part of the ventilating air can be an effective alternative, if implemented properly, until the capacity of the present system is improved. The additional airflow can be used to provide effective dilution of contaminants and higher flow velocities in the underground mine environment. Most applications of controlled recirculation involve taking a portion of the return air and passing it back into the intake to increase the air volume delivered to the desired work areas. OMSHR investigated a Nevada gold mine where shaft rehabilitation was in progress and one of the two main fans was shut down to allow reduced air velocity for safe shaft work. Underground booster fan operating pressures were kept constant to maintain airflow to work areas, inducing controlled recirculation in one work zone. Investigation into system behavior and the effects of recirculation on the working area during times of reduced primary ventilation system airflow would provide additional information on implementation of controlled recirculation into the system and how these events affect M/NM ventilation systems. The National Institute for Occupational Safety and Health monitored the ventilation district when both main fans were operating and another scenario with one of the units turned off for maintenance. Airflow and contaminants were measured to determine the exposure effects of induced recirculation on miner health. Surveys showed that 19% controlled recirculation created no change in the overall district airflow distribution and a small reduction in district fresh air intake. Total dust levels increased only modestly and respirable dust levels were also low. Diesel particulate matter

  17. Effect of cooling the recirculated exhaust gases on diesel engine emissions

    International Nuclear Information System (INIS)

    Abu-Hamdeh, Nidal H.

    2003-01-01

    Although combustion is essential in most energy generation processes, it is one of the major causes of air pollution. Spiral fin exhaust pipes were designed to study the effect of cooling the recirculated exhaust gases (EGR) of Diesel engines on the chemical composition of the exhaust gases and the reduction in the percentages of pollutant emissions. The gases examined in this study were oxides of nitrogen (NO x ), carbon dioxide (CO 2 ) and carbon monoxide (CO). In addition, O 2 concentration in the exhaust was measured. The two designs adopted in this study were exhaust pipes with solid and hollow fins around them. The first type uses air flow around the fins to cool the exhaust gases. The second type consists of hollow fins around the exhaust pipe to allow cooling water to flow in the hollow passage. Different combinations and arrangements of the solid and hollow fins exhaust pipes were used. It was found that decreasing the temperature of the EGR resulted in reductions in the oxides of nitrogen (NO x ) and carbon dioxide (CO 2 ) but increased the carbon monoxide (CO) in the exhaust gases. In addition, the oxygen (O 2 ) concentration in the exhaust was decreased. As a general trend, the percentages of reduction in the NO x gas concentrations were lower than the percentages of increase in the CO emissions as a result of cooling the EGR of a Diesel engine by a heat exchanger. Using water as a cooling medium decreased the exhaust gases temperature and the amount of pollutants more than did air as a cooling medium. In a separate series of tests, increasing the cooled EGR ratios decreased the exhaust NO x but increased the particulate matter concentrations in the exhaust gases

  18. Effect of cooling the recirculated exhaust gases on diesel engine emissions

    Energy Technology Data Exchange (ETDEWEB)

    Abu-Hamdeh, Nidal H. [Jordan Univ. of Science and Technology, Irbid (Jordan)

    2003-11-01

    Although combustion is essential in most energy generation processes, it is one of the major causes of air pollution. Spiral fin exhaust pipes were designed to study the effect of cooling the recirculated exhaust gases (EGR) of Diesel engines on the chemical composition of the exhaust gases and the reduction in the percentages of pollutant emissions. The gases examined in this study were oxides of nitrogen (NO{sub x}), carbon dioxide (CO{sub 2}) and carbon monoxide (CO). In addition, O{sub 2} concentration in the exhaust was measured. The two designs adopted in this study were exhaust pipes with solid and hollow fins around them. The first type uses air flow around the fins to cool the exhaust gases. The second type consists of hollow fins around the exhaust pipe to allow cooling water to flow in the hollow passage. Different combinations and arrangements of the solid and hollow fins exhaust pipes were used. It was found that decreasing the temperature of the EGR resulted in reductions in the oxides of nitrogen (NO{sub x}) and carbon dioxide (CO{sub 2}) but increased the carbon monoxide (CO) in the exhaust gases. In addition, the oxygen (O{sub 2}) concentration in the exhaust was decreased. As a general trend, the percentages of reduction in the NO{sub x} gas concentrations were lower than the percentages of increase in the CO emissions as a result of cooling the EGR of a Diesel engine by a heat exchanger. Using water as a cooling medium decreased the exhaust gases temperature and the amount of pollutants more than did air as a cooling medium. In a separate series of tests, increasing the cooled EGR ratios decreased the exhaust NO{sub x} but increased the particulate matter concentrations in the exhaust gases. (Author)

  19. Particle surface area and bacterial activity in recirculating aquaculture systems

    DEFF Research Database (Denmark)

    Pedersen, Per Bovbjerg; von Ahnen, Mathis; Fernandes, Paulo

    2017-01-01

    Suspended particles in recirculating aquaculture systems (RAS) provide surface area that can be colonized by bacteria. More particles accumulate as the intensity of recirculation increases thus potentially increasing the bacterial carrying capacity of the systems. Applying a recent, rapid, culture...... but may provide significant surface area. Hence, the study substantiates that particles in RAS provide surface area supporting bacterial activity, and that particles play a key role in controlling the bacterial carrying capacity at least in less intensive RAS. Applying fast, culture-independent techniques......-independent fluorometric detection method (Bactiquant®) for measuring bacterial activity, the current study explored the relationship between total particle surface area (TSA, derived from the size distribution of particles >5 μm) and bacterial activity in freshwater RAS operated at increasing intensity of recirculation...

  20. A very cool cooling system

    CERN Multimedia

    Antonella Del Rosso

    2015-01-01

    The NA62 Gigatracker is a jewel of technology: its sensor, which delivers the time of the crossing particles with a precision of less than 200 picoseconds (better than similar LHC detectors), has a cooling system that might become the precursor to a completely new detector technique.   The 115 metre long vacuum tank of the NA62 experiment. The NA62 Gigatracker (GTK) is composed of a set of three innovative silicon pixel detectors, whose job is to measure the arrival time and the position of the incoming beam particles. Installed in the heart of the NA62 detector, the silicon sensors are cooled down (to about -20 degrees Celsius) by a microfluidic silicon device. “The cooling system is needed to remove the heat produced by the readout chips the silicon sensor is bonded to,” explains Alessandro Mapelli, microsystems engineer working in the Physics department. “For the NA62 Gigatracker we have designed a cooling plate on top of which both the silicon sensor and the...

  1. Economic Feasibility of Recirculating Aquaculture Systems in Pangasius Farming

    NARCIS (Netherlands)

    Pham, T.A.N.; Gielen-Meuwissen, M.P.M.; Le, T.C.; Verreth, J.A.J.; Bosma, R.H.; Oude Lansink, A.G.J.M.

    2016-01-01

    This study aims to analyze the economic feasibility of recirculating aquaculture systems (RAS) in pangasius farming in Vietnam. The study uses a capital budgeting approach and accounts for uncertainty in key parameters. Stochastic simulation is used to simulate the economic performance of medium and

  2. High ratio recirculating gas compressor

    Science.gov (United States)

    Weinbrecht, J.F.

    1989-08-22

    A high ratio positive displacement recirculating rotary compressor is disclosed. The compressor includes an integral heat exchanger and recirculation conduits for returning cooled, high pressure discharge gas to the compressor housing to reducing heating of the compressor and enable higher pressure ratios to be sustained. The compressor features a recirculation system which results in continuous and uninterrupted flow of recirculation gas to the compressor with no direct leakage to either the discharge port or the intake port of the compressor, resulting in a capability of higher sustained pressure ratios without overheating of the compressor. 10 figs.

  3. Process fluid cooling system

    International Nuclear Information System (INIS)

    Farquhar, N.G.; Schwab, J.A.

    1977-01-01

    A system of heat exchangers is disclosed for cooling process fluids. The system is particularly applicable to cooling steam generator blowdown fluid in a nuclear plant prior to chemical purification of the fluid in which it minimizes the potential of boiling of the plant cooling water which cools the blowdown fluid

  4. Thermal tests of large recirculation cooling installations for nuclear power plants

    Science.gov (United States)

    Balunov, B. F.; Lychakov, V. D.; Il'in, V. A.; Shcheglov, A. A.; Maslov, O. P.; Rasskazova, N. A.; Rakhimov, R. Z.; Boyarov, R. A.

    2017-11-01

    The article presents the results from thermal tests of some recirculation installations for cooling air in nuclear power plant premises, including the volume under the containment. The cooling effect in such installations is produced by pumping water through their heat-transfer tubes. Air from the cooled room is blown by a fan through a bundle of transversely finned tubes and is removed to the same room after having been cooled. The finning of tubes used in the tested installations was made of Grade 08Kh18N10T and Grade 08Kh18N10 stainless steels or Grade AD1 aluminum. Steel fins were attached to the tube over their entire length by means of high-frequency welding. Aluminum fins were extruded on a lathe from the external tube sheath into which a steel tube had preliminarily been placed. Although the fin extrusion operation was accompanied by pressing the sheath inner part to the steel tube, tight contact between them over the entire surface was not fully achieved. In view of this, the air gap's thermal resistance coefficient was introduced in calculating the heat transfer between the heat-transferring media. The air gap average thickness was determined from the test results taking into account the gap variation with temperature due to different linear expansion coefficients of steel and aluminum. These tests, which are part of the acceptance tests of the considered installations, were carried out at the NPO TsKTI test facility and were mainly aimed at checking if the obtained thermal characteristics were consistent with the values calculated according to the standard recommendations with introduction, if necessary, of modifications to those recommendations.

  5. Cooled Water Production System,

    Science.gov (United States)

    The invention refers to the field of air conditioning and regards an apparatus for obtaining cooled water . The purpose of the invention is to develop...such a system for obtaining cooled water which would permit the maximum use of the cooling effect of the water -cooling tower.

  6. Engine with exhaust gas recirculation system and variable geometry turbocharger

    Science.gov (United States)

    Keating, Edward J.

    2015-11-03

    An engine assembly includes an intake assembly, an internal combustion engine defining a plurality of cylinders and configured to combust a fuel and produce exhaust gas, and an exhaust assembly in fluid communication with a first subset of the plurality of cylinders. Each of the plurality of cylinders are provided in fluid communication with the intake assembly. The exhaust assembly is provided in fluid communication with a first subset of the plurality of cylinders, and a dedicated exhaust gas recirculation system in fluid communication with both a second subset of the plurality of cylinders and with the intake assembly. The dedicated exhaust gas recirculation system is configured to route all of the exhaust gas from the second subset of the plurality of cylinders to the intake assembly. Finally, the engine assembly includes a turbocharger having a variable geometry turbine in fluid communication with the exhaust assembly.

  7. Dedicated exhaust gas recirculation control systems and methods

    Science.gov (United States)

    Sczomak, David P.; Narayanaswamy, Kushal; Keating, Edward J.

    2018-05-01

    An engine control system of a vehicle includes a fuel control module that controls fuel injection of a first cylinder of an engine based on a first target air/fuel ratio that is fuel lean relative to a stoichiometric air/fuel ratio and that controls fuel injection of a second cylinder of the engine based on a second target air/fuel ratio that is fuel rich relative to stoichiometry. The first cylinder outputs exhaust to a first three way catalyst (TWC), and the second cylinder outputs exhaust to an exhaust gas recirculation (EGR) valve. An EGR control module controls opening of the EGR valve to: (i) a second TWC that reacts with nitrogen oxides (NOx) in the exhaust and outputs ammonia to a selective catalytic reduction (SCR) catalyst; and (ii) a conduit that recirculates exhaust back to an intake system of the engine.

  8. Seismic proving test of BWR primary loop recirculation system

    International Nuclear Information System (INIS)

    Sato, H.; Shigeta, M.; Karasawa, Y.

    1987-01-01

    The seismic proving test of BWR Primary Loop Recirculation system is the second test to use the large-scale, high-performance vibration table of Tadotsu Engineering Laboratory. The purpose of this test is to prove the seismic reliability of the primary loop recirculation system (PLR), one of the most important safety components in the BWR nuclear plants, and also to confirm the adequacy of seismic analysis method used in the current seismic design. To achieve the purpose, the test was conducted under conditions and scale as near as possible to actual systems. The strength proving test was carried out with the test model mounted on the vibration table in consideration of basic design earthquake ground motions and other conditions to confirm the soundness of structure and the strength against earthquakes. Detailed analysis and analytic evaluation of the data obtained from the test was conducted to confirm the adequacy of the seismic analysis method and earthquake response analysis method used in the current seismic design. Then, on the basis of the results obtained, the seismic safety and reliability of BWR primary loop recirculation of the actual plants was fully evaluated

  9. Radiant Floor Cooling Systems

    DEFF Research Database (Denmark)

    Olesen, Bjarne W.

    2008-01-01

    In many countries, hydronic radiant floor systems are widely used for heating all types of buildings such as residential, churches, gymnasiums, hospitals, hangars, storage buildings, industrial buildings, and smaller offices. However, few systems are used for cooling.This article describes a floor...... cooling system that includes such considerations as thermal comfort of the occupants, which design parameters will influence the cooling capacity and how the system should be controlled. Examples of applications are presented....

  10. Cooling water distribution system

    Science.gov (United States)

    Orr, Richard

    1994-01-01

    A passive containment cooling system for a nuclear reactor containment vessel. Disclosed is a cooling water distribution system for introducing cooling water by gravity uniformly over the outer surface of a steel containment vessel using an interconnected series of radial guide elements, a plurality of circumferential collector elements and collector boxes to collect and feed the cooling water into distribution channels extending along the curved surface of the steel containment vessel. The cooling water is uniformly distributed over the curved surface by a plurality of weirs in the distribution channels.

  11. Investigation of a combined gas-steam system with flue gas recirculation

    Directory of Open Access Journals (Sweden)

    Chmielniak Tadeusz

    2016-06-01

    Full Text Available This article presents changes in the operating parameters of a combined gas-steam cycle with a CO2 capture installation and flue gas recirculation. Parametric equations are solved in a purpose-built mathematical model of the system using the Ebsilon Professional code. Recirculated flue gases from the heat recovery boiler outlet, after being cooled and dried, are fed together with primary air into the mixer and then into the gas turbine compressor. This leads to an increase in carbon dioxide concentration in the flue gases fed into the CO2 capture installation from 7.12 to 15.7%. As a consequence, there is a reduction in the demand for heat in the form of steam extracted from the turbine for the amine solution regeneration in the CO2 capture reactor. In addition, the flue gas recirculation involves a rise in the flue gas temperature (by 18 K at the heat recovery boiler inlet and makes it possible to produce more steam. These changes contribute to an increase in net electricity generation efficiency by 1%. The proposed model and the obtained results of numerical simulations are useful in the analysis of combined gas-steam cycles integrated with carbon dioxide separation from flue gases.

  12. Microscreen effects on water quality in replicated recirculating aquaculture systems

    DEFF Research Database (Denmark)

    Fernandes, Paulo; Pedersen, Lars-Flemming; Pedersen, Per Bovbjerg

    2015-01-01

    This study investigated the effects of three microscreen mesh sizes (100, 60 and 20 μm) on water quality and rainbow trout (Oncorhynchus mykiss) performance compared to a control group without microscreens, in triplicated recirculating aquaculture systems (RAS). Operational conditions were kept....... Fish performed similarly in all treatments. Preliminary screening of trout gills did not reveal any pathological changes related to microscreen filtration and the resulting water quality. Biofilter performance was also unaffected, with 0′-order nitrification rates (k0a) being equivalent for all twelve...

  13. Control methodologies based on geothermal recirculating aquaculture system

    International Nuclear Information System (INIS)

    Farghally, Hanaa M.; Atia, Doaa M.; El-madany, Hanaa T.; Fahmy, Faten H.

    2014-01-01

    One of the most common uses of geothermal heat is in RAS (recirculation aquaculture systems) where the water temperature is accurately controlled for optimum growing conditions for sustainable and intensive rearing of marine and freshwater fish. This paper presents a design for RAS rearing tank and plate type heat exchanger to be used with geothermal energy as a source of heating water. A well at Umm Huweitat on the Red Sea is used as a source of geothermal energy. The heat losses from the RAS tank are calculated using Geo Heat Center Software. Then a plate type heat exchanger is designed using the epsilon–NTU (number of transfer units) analysis method. For optimal growth and abundance of production, a different techniques of control system are applied to control the water temperature. The total system is built in MATLAB/SIMULINK to study the overall performance of control unit. Finally, a comparison between PI, Fuzzy-PID, and Fuzzy Logic Control has been done. - Highlights: • Design recirculating aquaculture system using geothermal energy. • Design a PI controller for water temperature control. • Design a Fuzzy logic controller for water temperature control. • Design a Fuzzy-PID controller for water temperature control. • Comparison between different control systems

  14. Design validation and performance of closed loop gas recirculation system

    International Nuclear Information System (INIS)

    Kalmani, S.D.; Majumder, G.; Mondal, N.K.; Shinde, R.R.; Joshi, A.V.

    2016-01-01

    A pilot experimental set up of the India Based Neutrino Observatory's ICAL detector has been operational for the last 4 years at TIFR, Mumbai. Twelve glass RPC detectors of size 2 × 2 m 2 , with a gas gap of 2 mm are under test in a closed loop gas recirculation system. These RPCs are continuously purged individually, with a gas mixture of R134a (C 2 H 2 F 4 ), isobutane (iC 4 H 10 ) and sulphur hexafluoride (SF 6 ) at a steady rate of 360 ml/h to maintain about one volume change a day. To economize gas mixture consumption and to reduce the effluents from being released into the atmosphere, a closed loop system has been designed, fabricated and installed at TIFR. The pressure and flow rate in the loop is controlled by mass flow controllers and pressure transmitters. The performance and integrity of RPCs in the pilot experimental set up is being monitored to assess the effect of periodic fluctuation and transients in atmospheric pressure and temperature, room pressure variation, flow pulsations, uniformity of gas distribution and power failures. The capability of closed loop gas recirculation system to respond to these changes is also studied. The conclusions from the above experiment are presented. The validations of the first design considerations and subsequent modifications have provided improved guidelines for the future design of the engineering module gas system.

  15. Continuous hydroponic wheat production using a recirculating system

    Science.gov (United States)

    Mackowiak, C. L.; Owens, L. P.; Hinkle, C. R.; Prince, R. P.

    1989-01-01

    Continuous crop production, where plants of various ages are growing simultaneously in a single recirculating nutrient solution, is a possible alternative to batch production in a Controlled Ecological Life Support System. A study was conducted at John F. Kennedy Space Center where 8 trays (0.24 sq m per tray) of Triticum aestivum L. Yecora Rojo were grown simultaneously in a growth chamber at 23 C, 65 percent relative humidity, 1000 ppm CO2, continuous light, with a continuous flow, thin film nutrient delivery system. The same modified Hoagland nutrient solution was recirculated through the plant trays from an 80 L reservoir throughout the study. It was maintained by periodic addition of water and nutrients based on chemical analyses of the solution. The study was conducted for 216 days, during which 24 trays of wheat were consecutively planted (one every 9 days), 16 of which were grown to maturity and harvested. The remaining 8 trays were harvested on day 216. Grain yields averaged 520 g m(exp -2), and had an average edible biomass of 32 percent. Consecutive yields were unaffected by nutrient solution age. It was concluded that continual wheat production will work in this system over an extended period of time. Certain micronutrient deficiencies and toxicities posed problems and must be addressed in future continuous production systems.

  16. Exergetic performance analysis of a recirculating aquaculture system

    International Nuclear Information System (INIS)

    Kucuk, Haydar; Midilli, Adnan; Ozdemir, Atilla; Cakmak, Eyuep; Dincer, Ibrahim

    2010-01-01

    This paper examines exergetic aspects of a Recirculation Aquaculture System (RAS) for Black Sea trout (Salmo trutta labrax) fingerling rearing at the Trabzon Central Fisheries Research Institute, Turkey. In its thermodynamic analysis, each component of the RAS is treated as a steady-state steady flow system and its exergetic efficiencies are studied. In addition, the following parameters are measured and recorded in experiments: the mass flow rates, inlet and outlet temperatures and of the system components, surrounding temperatures, and electrical work utilized by the components in the RAS. Based on these experimental data, inlet and outlet exergy values, exergy losses, and exergetic efficiencies of each component in the system are determined to assess their performance. Moreover, the overall system exergy efficiency is determined. The results show that exergy efficiencies of the system components are highly affected by varying input exergy flows as a function of the surrounding temperature and chiller's operating period.

  17. Off-gas recirculation system for nuclear reactors

    International Nuclear Information System (INIS)

    Eppler, M.; Lade, H.J.

    1975-01-01

    According to the invention, it is suggested to provide a buffer vessel in the ring main of the off-gas recirculation system for off-gases of a nuclear reactor to which all chambers or vessels which may contain radioactively contaminated gases are connected, within the connection line to outside air. This is to prevent the immediate release of an appreciable amount of gas to the outside air due to pressure variations conditioned by the sequence of operations - e.g. on the filling of the coolant storage. After the improvement, the released gas may be reduced to the amount of gas corresponding to the leakage gas flow entering the ring mains system. (TK) [de

  18. An evaluation of debris mobility within a PWR reactor coolant system during the recirculation mode

    International Nuclear Information System (INIS)

    Andreychek, T.S.

    1987-01-01

    To provide for the long-term cooling of the nuclear core of a Pressurized Water Rector (PWR) following a hypothetical Loss-of-Coolant Accidnet (LOCA), water is drawn from the containment sump and pumped into the reactor coolant system (RCS). It has been postulated that debris from the containment, such as dirt, sand, and paint from containment walls and in-containment equipment, could be carried into the containment sump due to the action of the RCS coolant that escapes from the breach in the piping and then flows to the sump. Once in the sump, this debris could be pumped into the Safety Injection System (SIS) and ultimately the RCS itself, causing the performance of the SIS to be degraded. Of particular interest is the potential for core blockage that may occur due to debris transport into the core region by the recirculating flow. This paper presents a method of evaluating the potential for debris from the sump to form core blockages under recirculating flow conditions following a hypothetical LOCA for a PWR

  19. Core cooling systems

    International Nuclear Information System (INIS)

    Hoeppner, G.

    1980-01-01

    The reactor cooling system transports the heat liberated in the reactor core to the component - heat exchanger, steam generator or turbine - where the energy is removed. This basic task can be performed with a variety of coolants circulating in appropriately designed cooling systems. The choice of any one system is governed by principles of economics and natural policies, the design is determined by the laws of nuclear physics, thermal-hydraulics and by the requirement of reliability and public safety. PWR- and BWR- reactors today generate the bulk of nuclear energy. Their primary cooling systems are discussed under the following aspects: 1. General design, nuclear physics constraints, energy transfer, hydraulics, thermodynamics. 2. Design and performance under conditions of steady state and mild transients; control systems. 3. Design and performance under conditions of severe transients and loss of coolant accidents; safety systems. (orig./RW)

  20. Simulation Analysis of the Four Configurations of Solar Desiccant Cooling System Using Evaporative Cooling in Tropical Weather in Malaysia

    Directory of Open Access Journals (Sweden)

    M. M. S. Dezfouli

    2014-01-01

    Full Text Available A high demand for air conditioning systems exists in hot and humid regions because of the warm climate during the year. The high energy consumption of conventional air conditioning system is the reason for our investigation of the solar desiccant cooling system as an energy-efficient cooling system. Four model configurations were considered to determine the best configuration of a solar desiccant cooling system: one-stage ventilation, one-stage recirculation, two-stage ventilation, and two-stage recirculation. These models were stimulated for 8,760 hr of operation under hot and humid weather in Malaysia. Several parameters (i.e., coefficient of performance or COP, room temperature and humidity ratio, and the solar fraction of each system were evaluated by detecting the temperature and humidity ratio of the different points of each configuration by TRNSYS simulation. The latent and sensible loads of the test room were 0.875 kW and 2.625 kW, respectively. By investigating the simulation results of the four systems, the ventilation modes were found to be higher than the recirculation modes in the one- and two-stage solar desiccant cooling systems. The isothermal dehumidification COP of the two-stage ventilation was higher than that of the two-stage recirculation. Hence, the two-stage ventilation mode desiccant cooling system in a hot and humid area has higher efficiency than the other configurations.

  1. Daily micro particle distribution of an experimental recirculating aquaculture system – A case study

    DEFF Research Database (Denmark)

    Fernandes, Paulo; Pedersen, Lars-Flemming; Pedersen, Per Bovbjerg

    2014-01-01

    The particle size distribution (PSD) in a recirculating aquaculture system (RAS) was investigated duringa 24-h cycle. PSD was analyzed in water sampled at several locations in a recirculation loop containing a60-m drum filter, a submerged fixed-bed biofilter and a trickling filter.In relation...

  2. Monitoring Cray Cooling Systems

    Energy Technology Data Exchange (ETDEWEB)

    Maxwell, Don E [ORNL; Ezell, Matthew A [ORNL; Becklehimer, Jeff [Cray, Inc.; Donovan, Matthew J [ORNL; Layton, Christopher C [ORNL

    2014-01-01

    While sites generally have systems in place to monitor the health of Cray computers themselves, often the cooling systems are ignored until a computer failure requires investigation into the source of the failure. The Liebert XDP units used to cool the Cray XE/XK models as well as the Cray proprietary cooling system used for the Cray XC30 models provide data useful for health monitoring. Unfortunately, this valuable information is often available only to custom solutions not accessible by a center-wide monitoring system or is simply ignored entirely. In this paper, methods and tools used to harvest the monitoring data available are discussed, and the implementation needed to integrate the data into a center-wide monitoring system at the Oak Ridge National Laboratory is provided.

  3. Turbine airfoil cooling system with cooling systems using high and low pressure cooling fluids

    Science.gov (United States)

    Marsh, Jan H.; Messmann, Stephen John; Scribner, Carmen Andrew

    2017-10-25

    A turbine airfoil cooling system including a low pressure cooling system and a high pressure cooling system for a turbine airfoil of a gas turbine engine is disclosed. In at least one embodiment, the low pressure cooling system may be an ambient air cooling system, and the high pressure cooling system may be a compressor bleed air cooling system. In at least one embodiment, the compressor bleed air cooling system in communication with a high pressure subsystem that may be a snubber cooling system positioned within a snubber. A delivery system including a movable air supply tube may be used to separate the low and high pressure cooling subsystems. The delivery system may enable high pressure cooling air to be passed to the snubber cooling system separate from low pressure cooling fluid supplied by the low pressure cooling system to other portions of the turbine airfoil cooling system.

  4. Reactor cooling system

    International Nuclear Information System (INIS)

    Kato, Etsuji.

    1979-01-01

    Purpose: To eliminate cleaning steps in the pipelines upon reactor shut-down by connecting a filtrating and desalting device to the cooling system to thereby always clean up the water in the pipelines. Constitution: A filtrating and desalting device is connected to the pipelines in the cooling system by way of drain valves and a check valve. Desalted water is taken out from the exit of the filtrating and desalting device and injected to one end of the cooling system pipelines by way of the drain valve and the check valve and then returned by way of another drain valve to the desalting device. Water in the pipelines is thus always desalted and the cleaning step in the pipelines is no more required in the shut-down. (Kawakami, Y.)

  5. ITER cooling systems

    International Nuclear Information System (INIS)

    Natalizio, A.; Hollies, R.E.; Sochaski, R.O.; Stubley, P.H.

    1992-06-01

    The ITER reference system uses low-temperature water for heat removal and high-temperature helium for bake-out. As these systems share common equipment, bake-out cannot be performed until the cooling system is drained and dried, and the reactor cannot be started until the helium has been purged from the cooling system. This study examines the feasibility of using a single high-temperature fluid to perform both heat removal and bake-out. The high temperature required for bake-out would also be in the range for power production. The study examines cost, operational benefits, and impact on reactor safety of two options: a high-pressure water system, and a low-pressure organic system. It was concluded that the cost savings and operational benefits are significant; there are no significant adverse safety impacts from operating either the water system or the organic system; and the capital costs of both systems are comparable

  6. Power plant including an exhaust gas recirculation system for injecting recirculated exhaust gases in the fuel and compressed air of a gas turbine engine

    Science.gov (United States)

    Anand, Ashok Kumar; Nagarjuna Reddy, Thirumala Reddy; Shaffer, Jason Brian; York, William David

    2014-05-13

    A power plant is provided and includes a gas turbine engine having a combustor in which compressed gas and fuel are mixed and combusted, first and second supply lines respectively coupled to the combustor and respectively configured to supply the compressed gas and the fuel to the combustor and an exhaust gas recirculation (EGR) system to re-circulate exhaust gas produced by the gas turbine engine toward the combustor. The EGR system is coupled to the first and second supply lines and configured to combine first and second portions of the re-circulated exhaust gas with the compressed gas and the fuel at the first and second supply lines, respectively.

  7. Development of the interactive model between Component Cooling Water System and Containment Cooling System using GOTHIC

    International Nuclear Information System (INIS)

    Byun, Choong Sup; Song, Dong Soo; Jun, Hwang Yong

    2006-01-01

    In a design point of view, component cooling water (CCW) system is not full-interactively designed with its heat loads. Heat loads are calculated from the CCW design flow and temperature condition which is determined with conservatism. Then the CCW heat exchanger is sized by using total maximized heat loads from above calculation. This approach does not give the optimized performance results and the exact trends of CCW system and the loads during transient. Therefore a combined model for performance analysis of containment and the component cooling water(CCW) system is developed by using GOTHIC software code. The model is verified by using the design parameters of component cooling water heat exchanger and the heat loads during the recirculation mode of loss of coolant accident scenario. This model may be used for calculating the realistic containment response and CCW performance, and increasing the ultimate heat sink temperature limits

  8. Environmental effects of cooling system alternatives at inland and coastal sites

    International Nuclear Information System (INIS)

    Miner, R.M.; Warrick, J.W.

    1975-01-01

    The environmental effects of alternative cooling systems for power plants in California were analyzed. At inland sites evaporative cooling systems must be used, with fresh water or waste water used as makeup. Because fresh water is scarce, most new plants would need to use agricultural or municipal waste waters. For agricultural waste water systems, disposing of the blowdown and dispersion of drift containing total dissolved solids are two significant problems requiring resolution. At coastal sites, once-through cooling systems or recirculating systems could be used. Once--through cooling causes fewer effects on the marine environment than do recirculating systems on the air and marine environment when oceans water makeup is used. In general, for a recirculating system, dispersing high-salinity blowdown in marine waters and the effects of salt water drift on the terrestrial ecology outweigh the effects of once-through warm water on marine life. (U.S.)

  9. Characterising organic matter in recirculating aquaculture systems with fluorescence EEM spectroscopy

    DEFF Research Database (Denmark)

    Hambly, Adam; Arvin, Erik; Pedersen, Lars-Flemming

    2015-01-01

    The potential of recirculating aquaculture systems (RAS) in the aquaculture industry is increasingly being acknowledged. Along with intensified application, the need to better characterise and understand the accumulated dissolved organic matter (DOM) within these systems increases. Mature RASs...

  10. Emergency core cooling system

    International Nuclear Information System (INIS)

    Ando, Masaki.

    1987-01-01

    Purpose: To actuate an automatic pressure down system (ADS) and a low pressure emergency core cooling system (ECCS) upon water level reduction of a nuclear reactor other than loss of coolant accidents (LOCA). Constitution: ADS in a BWR type reactor is disposed for reducing the pressure in a reactor container thereby enabling coolant injection from a low pressure ECCS upon LOCA. That is, ADS has been actuated by AND signal for a reactor water level low signal and a dry well pressure high signal. In the present invention, ADS can be actuated further also by AND signal of the reactor water level low signal, the high pressure ECCS and not-operation signal of reactor isolation cooling system. In such an emergency core cooling system thus constituted, ADS operates in the same manner as usual upon LOCA and, further, ADS is operated also upon loss of feedwater accident in the reactor pressure vessel in the case where there is a necessity for actuating the low pressure ECCS, although other high pressure ECCS and reactor isolation cooling system are not operated. Accordingly, it is possible to improve the reliability upon reactor core accident and mitigate the operator burden. (Horiuchi, T.)

  11. Wall-cooling-induced mixed-convection flow recirculation in a vertical square-array multi-rod channel

    International Nuclear Information System (INIS)

    Luangdilok, W.; Todreas, N.E.

    1989-01-01

    This work investigated the structure of penetrative flow recirculation and associated flow conditions in a multi-rod channel induced by interassembly heat transfer that causes cooling through channel walls. Three investigation approaches, experimental, numerical, and analytical were employed in a complimentary fashion. Physical experiments involved water flow visualization and temperature measurement in a 4x4 rod square channel. Numerical experiments involved 3-dimensional simulations of water and sodium flow in a 2x2-rod channels. An approximate reverse flow model including Prandtl number effect was developed. A correlating equation based on the model and experiments was verified for water to correctly predict the trend of the 4x4-rod experimental penetration depth data. (orig.)

  12. KE basin recirculation/skimmer/IX systems restart acceptance test report

    International Nuclear Information System (INIS)

    Derosa, D.C.

    1996-01-01

    The 105 KE Basin Recirculation System and Skimmer Loop have been upgraded to provide the flexibility to run the Ion Exchange Modules on either system to support spent fuel removal for the Spent Nuclear Fuel Project. This Acceptance Test Report Provides the documentation of the leak Testing for the construction work associated with the IXM inlet and outlet piping, places the cartridge filters back in service and provides the functional testing of the IXM's on the recirculation and skimmer systems

  13. Emergency core cooling system

    International Nuclear Information System (INIS)

    Abe, Nobuaki.

    1993-01-01

    A reactor comprises a static emergency reactor core cooling system having an automatic depressurization system and a gravitationally dropping type water injection system and a container cooling system by an isolation condenser. A depressurization pipeline of the automatic depressurization system connected to a reactor pressure vessel branches in the midway. The branched depressurizing pipelines are extended into an upper dry well and a lower dry well, in which depressurization valves are disposed at the top end portions of the pipelines respectively. If loss-of-coolant accidents should occur, the depressurization valve of the automatic depressurization system is actuated by lowering of water level in the pressure vessel. This causes nitrogen gases in the upper and the lower dry wells to transfer together with discharged steams effectively to a suppression pool passing through a bent tube. Accordingly, the gravitationally dropping type water injection system can be actuated faster. Further, subsequent cooling for the reactor vessel can be ensured sufficiently by the isolation condenser. (I.N.)

  14. Three dimensional computational fluid dynamic analysis of debris transport under emergency cooling water recirculation

    International Nuclear Information System (INIS)

    Park, Jong Woon

    2010-01-01

    This paper provides a computational fluid dynamic (CFD) analysis method on the evaluation of debris transport under emergency recirculation mode after loss of coolant accident of a nuclear power plant. Three dimensional reactor building floor geometrical model is constructed including flow obstacles larger than 6 inches such as mechanical components and equipments and considering various inlet flow paths from the upper reactor building such as break and spray flow. In the modeling of the inlet flows from the upper floors, effect of gravitational force was also reflected. For the precision of the analysis, 3 millions of tetrahedral-shaped meshes were generated. Reference calculation showed physically reasonable results. Sensitivity studies for mesh type and turbulence model showed very similar results to the reference case. This study provides useful information on the application of CFD to the evaluation of debris transport fraction for the design of new emergency sump filters. (orig.)

  15. Recirculating aquaculture production systems : an overview of different components, management, economics and technology

    NARCIS (Netherlands)

    Kals, J.

    2004-01-01

    Report of a literature study on Recirculating aquaculture production systems executed within the MRG ercirculation program. The report gives an overview of different components, management, economics and technology and is made by the Netherlands Institute for Fisheries Research (RIVO).

  16. Dietary carbohydrate composition can change waste production and biofilter load in recirculating aquaculture systems

    NARCIS (Netherlands)

    Meriac, A.; Eding, E.H.; Schrama, J.W.; Kamstra, A.; Verreth, J.A.J.

    2014-01-01

    This study investigated the effect of dietary carbohydrate composition on the production, recovery and degradability of fecal waste from rainbow trout (Oncorhynchus mykiss) in recirculating aquaculture systems (RAS). Dietary carbohydrate composition was altered by substituting starch with non-starch

  17. Activity buildup in the recirculation system of boiling water reactors

    International Nuclear Information System (INIS)

    Grauer, R.

    1987-05-01

    The deposition of activated corrosion products in the recirculation system of boiling water reactors produces increased radiation levels which lead to a corresponding increase in personnel irradiation dose rates during shut down and maintenance. The major part of this dose rate is due to Co-60. Based on a comprehensive literature study concerning this theme, the author has attempted to identify the individual stages of the activity build up and to classify their importance. The following areas are discussed in detail: - the origins of the corrosion products and of Co-59 in the reactor feedwater; - the consolidation of the cobalt in the fuel element crud deposits (activation); - the release and transport of the Co-60; - the build up of Co-60 in the corrosion products of the primary circuit. Existing models for the build up of cirquit radioactivity are discussed and the operating experience from selected reactors are summarized. Finally the state of the art of knowledge concerning the individual stages in the development of the activation build up is depicted. This highlights the existing gaps and thus identifies areas for possible R+D activities. Corrosion chemistry aspects of the cobald build up in the primary cirquit have already been studied on a broad basis and are continuing to be researched in a number of centers. The crystal chemistry of austenitic steel corrosion products poses a number of yet unanswered questions. There are major loopholes associated with an understanding of the activation processes of the cobalt deposited on the fuel elements and in the mass transfer of Co-60. For these processes, the most important influence stems from factors associated with colloid chemistry. In this respect there is ample room for new and original research contributions. It is recommended that sections 8 and 9 of this report should be read as an 'Executive Summary'. (author)

  18. Optimization of recirculating laminar air flow in operating room air conditioning systems

    Directory of Open Access Journals (Sweden)

    Enver Yalcin

    2016-04-01

    Full Text Available The laminar flow air-conditioning system with 100% fresh air is used in almost all operating rooms without discrimination in Turkey. The laminar flow device which is working with 100% fresh air should be absolutely used in Type 1A operating rooms. However, there is not mandatory to use of 100% fresh air for Type 1B defined as places performed simpler operation. Compared with recirculating laminar flow, energy needs of the laminar flow with 100 % fresh air has been emerged about 40% more than re-circulated air flow. Therefore, when a recirculating laminar flow device is operated instead of laminar flow system with 100% fresh air in the Type 1B operating room, annual energy consumption will be reduced. In this study, in an operating room with recirculating laminar flow, optimal conditions have been investigated in order to obtain laminar flow form by analyzing velocity distributions at various supply velocities by using computational fluid dynamics method (CFD.

  19. Influence of cooled exhaust gas recirculation on performance, emissions and combustion characteristics of LPG fuelled lean burn SI engine

    Science.gov (United States)

    Ravi, K.; Pradeep Bhasker, J.; Alexander, Jim; Porpatham, E.

    2017-11-01

    On fuel perspective, Liquefied Petroleum Gas (LPG) provides cleaner emissions and also facilitates lean burn signifying less fuel consumption and emissions. Lean burn technology can attain better efficiencies and lesser combustion temperatures but this temperature is quite sufficient to facilitate formation of nitrogen oxide (NOx). Exhaust Gas Recirculation (EGR) for NOx reduction has been considered allover but extremely little literatures exist on the consequence of EGR on lean burn LPG fuelled spark ignition (SI) engine. The following research is carried out to find the optimal rate of EGR addition to reduce NOx emissions without settling on performance and combustion characteristics. A single cylinder diesel engine is altered to operate as LPG fuelled SI engine at a compression ratio of 10.5:1 and arrangements to provide different ratios of cooled EGR in the intake manifold. Investigations are done to arrive at optimum ratio of the EGR to reduce emissions without compromising on performance. Significant reductions in NOx emissions alongside HC and CO emissions were seen. Higher percentages of EGR further diluted the charge and lead to improper combustion and thus increased hydrocarbon emissions. Cooled EGR reduced the peak in-cylinder temperature which reduced NOx emissions but lead to misfire at lower lean limits.

  20. ITER cooling system

    International Nuclear Information System (INIS)

    Kveton, O.K.

    1990-11-01

    The present specification of the ITER cooling system does not permit its operation with water above 150 C. However, the first wall needs to be heated to higher temperatures during conditioning at 250 C and bake-out at 350 C. In order to use the cooling water for these operations the cooling system would have to operate during conditioning at 37 Bar and during bake-out at 164 Bar. This is undesirable from the safety analysis point of view, and alternative heating methods are to be found. This review suggests that superheated steam or gas heating can be used for both baking and conditioning. The blanket design must consider the use of dual heat transfer media, allowing for change from one to another in both directions. Transfer from water to gas or steam is the most intricate and risky part of the entire heating process. Superheated steam conditioning appears unfavorable. The use of inert gas is recommended, although alternative heating fluids such as organic coolant should be investigated

  1. Dietary carbohydrates and denitrification in recirculating aquaculture systems

    OpenAIRE

    Meriac, A.

    2014-01-01

    Due to overfishing of global fish stocks and increasing fish meal prices, plant ingredients are being increasingly used as an alternative source of protein in fish feeds. However, the inclusion of unpurified plant ingredients will also increase the content of fibers in feeds. Fibers are nearly indigestible and will therefore increase solid waste production in aquaculture. This solid waste can be used to as a carbon source for denitrification to control nitrate levels in recirculating aquacul...

  2. Marginal costs of water savings from cooling system retrofits: a case study for Texas power plants

    Science.gov (United States)

    Loew, Aviva; Jaramillo, Paulina; Zhai, Haibo

    2016-10-01

    The water demands of power plant cooling systems may strain water supply and make power generation vulnerable to water scarcity. Cooling systems range in their rates of water use, capital investment, and annual costs. Using Texas as a case study, we examined the cost of retrofitting existing coal and natural gas combined-cycle (NGCC) power plants with alternative cooling systems, either wet recirculating towers or air-cooled condensers for dry cooling. We applied a power plant assessment tool to model existing power plants in terms of their key plant attributes and site-specific meteorological conditions and then estimated operation characteristics of retrofitted plants and retrofit costs. We determined the anticipated annual reductions in water withdrawals and the cost-per-gallon of water saved by retrofits in both deterministic and probabilistic forms. The results demonstrate that replacing once-through cooling at coal-fired power plants with wet recirculating towers has the lowest cost per reduced water withdrawals, on average. The average marginal cost of water withdrawal savings for dry-cooling retrofits at coal-fired plants is approximately 0.68 cents per gallon, while the marginal recirculating retrofit cost is 0.008 cents per gallon. For NGCC plants, the average marginal costs of water withdrawal savings for dry-cooling and recirculating towers are 1.78 and 0.037 cents per gallon, respectively.

  3. Lamination cooling system

    Science.gov (United States)

    Rippel, Wally E.; Kobayashi, Daryl M.

    2005-10-11

    An electric motor, transformer or inductor having a lamination cooling system including a stack of laminations, each defining a plurality of apertures at least partially coincident with apertures of adjacent laminations. The apertures define a plurality of cooling-fluid passageways through the lamination stack, and gaps between the adjacent laminations are sealed to prevent a liquid cooling fluid in the passageways from escaping between the laminations. The gaps are sealed by injecting a heat-cured sealant into the passageways, expelling excess sealant, and heat-curing the lamination stack. The apertures of each lamination can be coincident with the same-sized apertures of adjacent laminations to form straight passageways, or they can vary in size, shape and/or position to form non-axial passageways, angled passageways, bidirectional passageways, and manifold sections of passageways that connect a plurality of different passageway sections. Manifold members adjoin opposite ends of the lamination stack, and each is configured with one or more cavities to act as a manifold to adjacent passageway ends. Complex manifold arrangements can create bidirectional flow in a variety of patterns.

  4. Hybrid radiator cooling system

    Science.gov (United States)

    France, David M.; Smith, David S.; Yu, Wenhua; Routbort, Jules L.

    2016-03-15

    A method and hybrid radiator-cooling apparatus for implementing enhanced radiator-cooling are provided. The hybrid radiator-cooling apparatus includes an air-side finned surface for air cooling; an elongated vertically extending surface extending outwardly from the air-side finned surface on a downstream air-side of the hybrid radiator; and a water supply for selectively providing evaporative cooling with water flow by gravity on the elongated vertically extending surface.

  5. Rotary engine cooling system

    Science.gov (United States)

    Jones, Charles (Inventor); Gigon, Richard M. (Inventor); Blum, Edward J. (Inventor)

    1985-01-01

    A rotary engine has a substantially trochoidal-shaped housing cavity in which a rotor planetates. A cooling system for the engine directs coolant along a single series path consisting of series connected groups of passages. Coolant enters near the intake port, passes downwardly and axially through the cooler regions of the engine, then passes upwardly and axially through the hotter regions. By first flowing through the coolest regions, coolant pressure is reduced, thus reducing the saturation temperature of the coolant and thereby enhancing the nucleate boiling heat transfer mechanism which predominates in the high heat flux region of the engine during high power level operation.

  6. System and method for regulating EGR cooling using a rankine cycle

    Science.gov (United States)

    Ernst, Timothy C.; Morris, Dave

    2015-12-22

    This disclosure relates to a waste heat recovery (WHR) system and method for regulating exhaust gas recirculation (EGR) cooling, and more particularly, to a Rankine cycle WHR system and method, including a recuperator bypass arrangement to regulate EGR exhaust gas cooling for engine efficiency improvement and thermal management. This disclosure describes other unique bypass arrangements for increased flexibility in the ability to regulate EGR exhaust gas cooling.

  7. A recirculating hydroponic system for studying peanut (Arachis hypogaea L.)

    Science.gov (United States)

    Mackowiak, C. L.; Wheeler, R. M.; Stutte, G. W.; Yorio, N. C.; Ruffe, L. M.; Sager, J. C. (Principal Investigator)

    1998-01-01

    Peanut (Arachis hypogaea L.) plants were grown hydroponically, using continuously recirculating nutrient solution. Two culture tray designs were tested; one tray design used only nutrient solution, while the other used a sphagnum-filled pod development compartment just beneath the cover and above the nutrient solution. Both trays were fitted with slotted covers to allow developing gynophores to reach the root zone. Peanut seed yields averaged 350 gm-2 dry mass, regardless of tray design, suggesting that substrate is not required for hydroponic peanut production.

  8. NUTRIENTS DYNIMIC IN AN AQUAPONIC RECIRCULATING SYSTEM FOR STURGEON AND LETTUCE (LACTUCA SATIVA PRODUCTION

    Directory of Open Access Journals (Sweden)

    LORENA SFETCU

    2008-10-01

    Full Text Available Aquaponics are modern production systems, which integrate the aquaculture technology with hydroponic systems (vegetable production without soil with a goal of fructification of residual nutrients resulted from metabolic activity of fish biomass as high quality vegetable biomass sealable as ecological products. In the present study, as a first step in aquaponic recirculating systems evaluation, the authors aim to compare two types of recirculating systems: classical (hereby noted with RAS and integrated/aquaponic (RAS_A regarding water quality parameters generally, and TAN (total ammonia nitrogen production and transformation, particularly.

  9. Cooling water injection system

    International Nuclear Information System (INIS)

    Inai, Nobuhiko.

    1989-01-01

    In a BWR type reactor, ECCS system is constituted as a so-called stand-by system which is not used during usual operation and there is a significant discontinuity in relation with the usual system. It is extremely important that ECCS operates upon occurrence of accidents just as specified. In view of the above in the present invention, the stand-by system is disposed along the same line with the usual system. That is, a driving water supply pump for supplying driving water to a jet pump is driven by a driving mechanism. The driving mechanism drives continuously the driving water supply pump in a case if an expected accident such as loss of the function of the water supply pump, as well as during normal operation. That is, all of the water supply pump, jet pump, driving water supply pump and driving mechanism therefor are caused to operate also during normal operation. The operation of them are not initiated upon accident. Thus, the cooling water injection system can perform at high reliability to remarkably improve the plant safety. (K.M.)

  10. Effect of recirculation rate on methane production and SEBAR system performance using active stage digester.

    Science.gov (United States)

    Tubtong, Cheevanuch; Towprayoon, Sirintornthep; Connor, Michael Anthony; Chaiprasert, Pawinee; Nopharatana, Annop

    2010-09-01

    A project was undertaken to examine the feasibility of treating organic wastes from Thai fruit and vegetable markets using the sequential batch anaerobic digester (SEBAR) approach. A key feature of the SEBAR system is the regular interchanging, or recirculation, of portions of leachate between each freshly filled digester and a support digester to which it is coupled until it is ready to operate independently. Leachate transfer from this support digester to the fresh waste digester provides additional alkalinity to help counteract the effects of early high acid release rates; it also helps build a balanced microbial population in the fresh waste digester. To optimize the leachate recirculation process, the effect of varying the quantities of leachate interchanged between freshly filled waste digesters and the still highly active support digesters to which they were coupled was studied. It was found that increasing the recirculation rate accelerated the onset of both waste degradation and methane production. The increasing of recirculation rate from 10% to 20% and 10% to 30% could reduce the SEBAR cycle period by approximately 7% and 22% without significant reduction in the amount of methane obtained from the systems. The methane yields were 0.0063, 0.0068 and 0.0077 l g(-1) VS added in the NEW digester per day using leachate recirculation rates of 10%, 20% and 30%, respectively. This finding has potentially important practical and economic implications for those using the SEBAR system to add value to market waste.

  11. Control oriented modeling of ejector in anode gas recirculation solid oxygen fuel cell systems

    International Nuclear Information System (INIS)

    Zhu Yinhai; Li Yanzhong; Cai Wenjian

    2011-01-01

    A one-equation model is proposed for fuel ejector in anode gas recirculation solid oxide fuel cell (SOFC) system. Firstly, the fundamental governing equations are established by employing the thermodynamic, fluid dynamic principles and chemical constraints inside the ejector; secondly, the one-equation model is derived by using the parameter analysis and lumped-parameter method. Finally, the computational fluid dynamics (CFD) technique is employed to obtain the source data for determining the model parameters. The effectiveness of the model is studied under a wide range of operation conditions. The effect of ejector performance on the anode gas recirculation SOFC system is also discussed. The presented model, which only contains four constant parameters, is useful in real-time control and optimization of fuel ejector in the anode gas recirculation SOFC system.

  12. Core cooling system for reactor

    International Nuclear Information System (INIS)

    Kondo, Ryoichi; Amada, Tatsuo.

    1976-01-01

    Purpose: To improve the function of residual heat dissipation from the reactor core in case of emergency by providing a secondary cooling system flow channel, through which fluid having been subjected to heat exchange with the fluid flowing in a primary cooling system flow channel flows, with a core residual heat removal system in parallel with a main cooling system provided with a steam generator. Constitution: Heat generated in the core during normal reactor operation is transferred from a primary cooling system flow channel to a secondary cooling system flow channel through a main heat exchanger and then transferred through a steam generator to a water-steam system flow channel. In the event if removal of heat from the core by the main cooling system becomes impossible due to such cause as breakage of the duct line of the primary cooling system flow channel or a trouble in a primary cooling system pump, a flow control valve is opened, and steam generator inlet and outlet valves are closed, thus increasing the flow rate in the core residual heat removal system. Thereafter, a blower is started to cause dissipation of the core residual heat from the flow channel of a system for heat dissipation to atmosphere. (Seki, T.)

  13. Steroids accumulate in the rearing water of commercial recirculating aquaculture systems

    NARCIS (Netherlands)

    Mota, V.C.; Martins, C.I.; Eding, E.H.; Canário, A.V.M.; Verreth, J.A.J.

    2014-01-01

    Little information is available on steroid concentrations in the rearing water of aquaculture systems and whether they accumulate in recirculating aquaculture systems (RAS). Therefore this study aimed at determining (1) the concentrations and variation of cortisol and sex steroids in RAS, (2) the

  14. Reliability analysis of air recirculation and refrigeration systems of Angra-1 reactor contaiment: a reevaluation

    International Nuclear Information System (INIS)

    Oliveira, L.F.S. de; Fleming, P.V.; Frutuoso e Melo, P.F.F.

    1983-01-01

    A realiability analysis of the air refrigeration and recirculation containment systems (ARRCS) of Angra-1 nuclear power plants, were done, aiming to evaluate the probabilities of occurence of a several accident. The systems were analysed for a 24 hours accident, including time failures and demand failures [pt

  15. New developments in recirculating aquaculture systems in Europe: a perspective on environmental sustainability

    NARCIS (Netherlands)

    Martins, C.I.; Eding, E.H.; Verdegem, M.C.J.; Heinsbroek, L.T.N.; Schneider, O.; Blancheton, J.P.; Roque dÓrbcastel, E.; Verreth, J.A.J.

    2010-01-01

    The dual objective of sustainable aquaculture, i.e., to produce food while sustaining natural resources is achieved only when production systems with a minimum ecological impact are used. Recirculating aquaculture systems (RASs) provide opportunities to reduce water usage and to improve waste

  16. Fulminant hepatic failure following marijuana drug abuse: Molecular adsorbent recirculation system therapy

    Directory of Open Access Journals (Sweden)

    G Swarnalatha

    2013-01-01

    Full Text Available Marijuana is used for psychoactive and recreational purpose. We report a case of fulminant hepatic failure following marijuana drug abuse who recovered following artificial support systems for acute liver failure. There is no published literature of management of marijuana intoxication with molecular adsorbent recirculation system (MARS. MARS is effective and safe in patients with fulminant hepatic failure following marijuana intoxication.

  17. Emergency core cooling system

    International Nuclear Information System (INIS)

    Sato, Akira; Kobayashi, Masahide.

    1983-01-01

    Purpose: To enable a stable operation of an emergency core cooling system by preventing the system from the automatic stopping at an abnormally high level of the reactor water during its operation. Constitution: A pump flow rate signal and a reactor water level signal are used and, when the reactor water level is increased to a predetermined level, the pump flow rate is controlled by the reactor water level signal instead of the flow rate signal. Specifically, when the reactor water level is gradually increased by the water injection from the pump and exceeds a setting signal for the water level, the water level deviation signal acts as a demand signal for the decrease in the flow rate of the pump and the output signal from the water level controller is also decreased depending on the control constant. At a certain point, the output signal from the water level controller becomes smaller than the output signal from the flow rate controller. Thus, the output signal from the water level controller is outputted as the output signal for the lower level preference device. In this way, the reactor water level and the pump flow rate can be controlled within a range not exceeding the predetermined pump flow rate. (Horiuchi, T.)

  18. Evaluation of a rainbow trout (Oncorhynchus mikyss culture water recirculating system

    Directory of Open Access Journals (Sweden)

    Iván Sánchez O.

    2014-09-01

    Full Text Available Objective. To evaluate a water recirculation system for rainbow trout fish cultures at the recirculating laboratory of the Aquaculture Engineering Production Program of University of Nariño. Materials and Methods. 324 rainbow trout (Oncorhynchus mikyss fries were cultured in 12 plastic tanks with a capacity of 250 L in an aquaculture recirculating system the treatment system of which was made up by a conventional sedimentation tank, a fixed stand upflow biofilter with recycled PVC tube pieces and a natural degassing system; the sedimentation unit effluent was pumped up to a reservoir tank using a 2 HP centrifugal pump after being subject to gravity through the biofilter and to be then distributed to the 12 culture units to which a constant amount of air from a blower was injected. Results. The water treatment system removed 31% of total suspended solids, 9.5% of total ammonia nitrogen, and increased dissolved oxygen to the final effluent in 6.5%. An increase of 305% in biomass was calculated during 75 days, the mortality percentage registered throughout the study period was 4.9%. Conclusions. The water treatment system maintained the physicochemical water quality parameters within the values recommended for the species. The increase in weight and size, food conversion, mortality and biomass production reported normal values for rainbow trout fish culture in recirculating systems.

  19. Use of planted biofilters in integrated recirculating aquaculture-hydroponics systems in the Mekong Delta, Vietnam

    DEFF Research Database (Denmark)

    Trang, N.T.D.; Brix, Hans

    2014-01-01

    The feasibility of using planted biofilters for purification of recirculated aquaculture water in the Mekong Delta of Vietnam was assessed. The plant trenches were able to clean tilapia aquaculture water and to maintain good water quality in the fish tanks without renewal of the water. NH4-N was ...... rates of 725 kg N and 234 kg P ha-1 year-1. This research demonstrates that integrated recirculating aquaculture-hydroponics (aquaponics) systems provide significant water savings and nutrient recycling as compared with traditional fish ponds....

  20. The Effect of Effluent Recirculation in a Semi-Continuous Two-Stage Anaerobic Digestion System

    Directory of Open Access Journals (Sweden)

    Karthik Rajendran

    2013-06-01

    Full Text Available The effect of recirculation in increasing organic loading rate (OLR and decreasing hydraulic retention time (HRT in a semi-continuous two-stage anaerobic digestion system using stirred tank reactor (CSTR and an upflow anaerobic sludge bed (UASB was evaluated. Two-parallel processes were in operation for 100 days, one with recirculation (closed system and the other without recirculation (open system. For this purpose, two structurally different carbohydrate-based substrates were used; starch and cotton. The digestion of starch and cotton in the closed system resulted in production of 91% and 80% of the theoretical methane yield during the first 60 days. In contrast, in the open system the methane yield was decreased to 82% and 56% of the theoretical value, for starch and cotton, respectively. The OLR could successfully be increased to 4 gVS/L/day for cotton and 10 gVS/L/day for starch. It is concluded that the recirculation supports the microorganisms for effective hydrolysis of polyhydrocarbons in CSTR and to preserve the nutrients in the system at higher OLRs, thereby improving the overall performance and stability of the process.

  1. The accumulation of substances in Recirculating Aquaculture Systems (RAS) affects embryonic and larval development in common carp Cyprinus carpio

    NARCIS (Netherlands)

    Martins, C.I.; Pristin, M.G.; Ende, S.S.W.; Eding, E.H.; Verreth, J.A.J.

    2009-01-01

    The accumulation of substances in Recirculating Aquaculture Systems (RAS) may impair the growth and welfare of fish. To test the severity of contaminants accumulated in RAS, early-life stages of fish were used. Ultrafiltered water from two Recirculating Aquaculture Systems (RAS), one RAS with a high

  2. COOLING STAGES OF CRYOGENIC SYSTEMS

    OpenAIRE

    Троценко, А. В.

    2011-01-01

    The formalized definition for cooling stage of low temperature system is done. Based on existing information about the known cryogenic unit cycles the possible types of cooling stages are single out. From analyses of these stages their classification by various characteristics is suggested. The results of thermodynamic optimization of final throttle stage of cooling, which are used as working fluids helium, hydrogen and nitrogen, are shown.

  3. Failure investigation of stem of valve disc in reactor recirculation system of TAPS Unit-1

    International Nuclear Information System (INIS)

    Ramadasan, E.; Bahl, J.K.; Sivaramakrishnan, K.S.

    1986-01-01

    Failure analysis was carried out of failed 17-4 PH stainless steel stem of the valve disc in reactor recirculation system of Unit-1 of Tarapur Atomic Power Station. The examination revealed that the stem failed due to fatigue, accelerated by corrosion. Recommendations have been made to avoid such failures. (author)

  4. Bacterial activity dynamics in the water phase during start-up of recirculating aquaculture systems

    DEFF Research Database (Denmark)

    Rojas-Tirado, Paula Andrea; Pedersen, Per Bovbjerg; Pedersen, Lars-Flemming

    2017-01-01

    tMicrobial water quality in recirculating aquaculture systems (RAS) is important for successful RAS opera-tion but difficult to assess and control. There is a need to identify factors affecting changes in the bacterialdynamics – in terms of abundance and activity – to get the information needed...

  5. Experimental Bleaching of a Reef-Building Coral Using a Simplified Recirculating Laboratory Exposure System

    Science.gov (United States)

    Determining stressor-response relationships in reef building corals is a critical need for researchers because of global declines in coral reef ecosystems. A simplified recirculating coral exposure system for laboratory testing of a diversity of species and morphologies of reef b...

  6. Observations on side-swimming rainbow trout Oncorhynchus mykiss in water recirculation aquaculture systems

    Science.gov (United States)

    During a controlled 6-month study using six replicated water recirculation aquaculture systems (WRAS), it was observed that rainbow trout Oncorhynchus mykiss in all WRAS exhibited a higher-than-normal prevalence of side-swimming (i.e. controlled, forward swimming, but with misaligned orientation suc...

  7. Adoption of Recirculating Aquaculture Systems in Pangasius Farms: A Choice Experiment

    NARCIS (Netherlands)

    Pham, T.A.N.; Gielen-Meuwissen, M.P.M.; Le, T.T.; Bosma, R.H.; Oude Lansink, A.G.J.M.

    2015-01-01

    A growing number of European customers’ demands certified pangasius such as ASC in order to ensure sustainable production. Implementing Recirculating Aquaculture Systems (RAS) contributes to an improved water quality, a key issue in achieving ASC certification. This study uses a choice experiment to

  8. Adoption of Recirculating Aquaculture Systems in Large Pangasius Farms: A Choice Experiment

    NARCIS (Netherlands)

    Pham, T.A.N.; Gielen-Meuwissen, M.P.M.; Le, T.C.; Verreth, J.A.J.; Bosma, R.H.; Oude Lansink, A.G.J.M.

    2016-01-01

    A growing number of European customers’ demands certified pangasius such as ASC in order to ensure sustainable production. Implementing Recirculating Aquaculture Systems (RAS) contributes to an improved water quality, a key issue in achieving ASC certification. This study uses a choice experiment to

  9. Evaluation of commercial marine fish feeds for production of juvenile cobia in recirculating aquaculture systems

    Science.gov (United States)

    The effect of feeding three commercially available diets manufactured by three U.S. feed companies on production characteristics and body composition of juvenile cobia Rachycentron canadum reared in recirculating aquaculture systems (RAS) was evaluated in a 57 d growth trial. Juvenile cobia (26.7 +...

  10. Water cortisol and testosterone in Nile tilapia (Oreochromis niloticus) recirculating aquaculture systems

    NARCIS (Netherlands)

    Mota, Vasco C.; Martins, Catarina I.M.; Eding, Ep H.; Canário, Adelino V.M.; Verreth, Johan A.J.

    2017-01-01

    The accumulation of steroids released by fish in recirculating aquaculture systems (RAS) may potentially influence their physiology and behavior. The present study examined the release rate of cortisol and testosterone by Nile tilapia, Oreochromis niloticus, and their accumulation in six identical

  11. Emergency core cooling system

    International Nuclear Information System (INIS)

    Arai, Kenji; Oikawa, Hirohide.

    1990-01-01

    The device according to this invention can ensure cooling water required for emerency core cooling upon emergence such as abnormally, for example, loss of coolant accident, without using dynamic equipments such as a centrifugal pump or large-scaled tank. The device comprises a pressure accumulation tank containing a high pressure nitrogen gas and cooling water inside, a condensate storage tank, a pressure suppression pool and a jet stream pump. In this device there are disposed a pipeline for guiding cooling water in the pressure accumulation tank as a jetting water to a jetting stream pump, a pipeline for guiding cooling water stored in the condensate storage tank and the pressure suppression pool as pumped water to the jetting pump and, further, a pipeline for guiding the discharged water from the jet stream pump which is a mixed stream of pumped water and jetting water into the reactor pressure vessel. In this constitution, a sufficient amount of water ranging from relatively high pressure to low pressure can be supplied into the reactor pressure vessel, without increasing the size of the pressure accumulation tank. (I.S.)

  12. 46 CFR 153.432 - Cooling systems.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Cooling systems. 153.432 Section 153.432 Shipping COAST... Control Systems § 153.432 Cooling systems. (a) Each cargo cooling system must have an equivalent standby... cooling system. (b) Each tankship that has a cargo tank with a required cooling system must have a manual...

  13. Cooling water systems design using process integration

    CSIR Research Space (South Africa)

    Gololo, KV

    2010-09-01

    Full Text Available Cooling water systems are generally designed with a set of heat exchangers arranged in parallel. This arrangement results in higher cooling water flowrate and low cooling water return temperature thus reducing cooling tower efficiency. Previous...

  14. Emergency core cooling system

    International Nuclear Information System (INIS)

    Kato, Ken.

    1989-01-01

    In PWR type reactors, a cooling water spray portion of emergency core cooling pipelines incorporated into pipelines on high temperature side is protruded to the inside of an upper plenum. Upon rupture of primary pipelines, pressure in a pressure vessel is abruptly reduced to generate a great amount of steams in the reactor core, which are discharged at a high flow rate into the primary pipelines on high temperature side. However, since the inside of the upper plenum has a larger area and the steam flow is slow, as compared with that of the pipelines on the high temperature side, ECCS water can surely be supplied into the reactor core to promote the re-flooding of the reactor core and effectively cool the reactor. Since the nuclear reactor can effectively be cooled to enable the promotion of pressure reduction and effective supply of coolants during the period of pressure reduction upon LOCA, the capacity of the pressure accumulation vessel can be decreased. Further, the re-flooding time for the reactor is shortened to provide an effect contributing to the improvement of the safety and the reduction of the cost. (N.H.)

  15. FIST/6IB1, BWR/6 System Responses to Intermediate Break in Recirculation Suction Line LINE

    International Nuclear Information System (INIS)

    1993-01-01

    1 - Description of test facility: BWR/6-218 standard plant. A full size bundle with electrically heated rods is used to simulate the reactor core. A scaling ratio of 1/624 is applied in the design of the system components. Key features of the FIST facility include: (1) Full height test vessel and internals; (2) correctly scaled fluid volume distribution; (3) simulation of ECCS, S/RV, and ADS; (4) level trip capability; (5) heated feedwater supply system, which provides the capability for steady state operation. 2 - Description of test: Test 6IB1 investigates system responses to an intermediate break in the recirculation suction line. BWR system licensing evaluations for various size recirculation break LOCA's indicates that a break size of about 0.2 sq.ft., without LPCS operation, is the highest PCT case for the intermediate break LOCA. Test 6IB1 simulates this event

  16. Implementation of Exhaust Gas Recirculation for Double Stage Waste Heat Recovery System on Large Container Vessel

    DEFF Research Database (Denmark)

    Andreasen, Morten; Marissal, Matthieu; Sørensen, Kim

    2014-01-01

    Concerned to push ships to have a lower impact on the environment, the International Maritime Organization are implementing stricter regulation of NOx and SOx emissions, called Tier III, within emission control areas (ECAs). Waste Heat Recovery Systems (WHRS) on container ships consist...... of recovering some of the waste heat from the exhaust gas. This heat is converted into electrical energy used on-board instead of using auxiliary engines. Exhaust Gas Recirculation (EGR) systems, are recirculating a part of the exhaust gas through the engine combustion chamber to reduce emissions. WHRS combined...... with EGR is a potential way to improve system efficiency while reducing emissions. This paper investigates the feasibility of combining the two systems. EGR dilutes the fuel, lowering the combustion temperature and thereby the formation of NOx, to reach Tier III limitation. A double stage WHRS is set up...

  17. Superconducting magnet cooling system

    Science.gov (United States)

    Vander Arend, Peter C.; Fowler, William B.

    1977-01-01

    A device is provided for cooling a conductor to the superconducting state. The conductor is positioned within an inner conduit through which is flowing a supercooled liquid coolant in physical contact with the conductor. The inner conduit is positioned within an outer conduit so that an annular open space is formed therebetween. Through the annular space is flowing coolant in the boiling liquid state. Heat generated by the conductor is transferred by convection within the supercooled liquid coolant to the inner wall of the inner conduit and then is removed by the boiling liquid coolant, making the heat removal from the conductor relatively independent of conductor length.

  18. Purification Performance and Production of a Re-circulating Pond Aquaculture System Based on Paddy Field

    OpenAIRE

    Gu Li; Shi-yang Zhang; Ling Tao; Xiao-li Li; Jing-hua Song; Chun-xue Zhang; Jian-qiang Zhu

    2012-01-01

    Developing improved aquaculture systems with a more efficient use of water and less environmental impact is becoming a crying need. A re-circulating aquaculture system consisting of paddy field and fish pond is a new culture mode due to aquaculture combing with agriculture. The present study focused on the purification capacity of the paddy field on nitrogen, phosphorus and organic matter, the fluctuation trend of water quality conditions during the whole rearing process and the culture effic...

  19. Cryogenic cooling system for HTS cable

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, Shigeru [Taiyo Nippon Sanso, Tsukuba (Japan)

    2017-06-15

    Recently, Research and development activity of HTS (High Temperature Superconducting) power application is very progressive worldwide. Especially, HTS cable system and HTSFCL (HTS Fault current limiter) system are proceeding to practical stages. In such system and equipment, cryogenic cooling system, which makes HTS equipment cooled lower than critical temperature, is one of crucial components. In this article, cryogenic cooling system for HTS application, mainly cable, is reviewed. Cryogenic cooling system can be categorized into conduction cooling system and immersion cooling system. In practical HTS power application area, immersion cooling system with sub-cooled liquid nitrogen is preferred. The immersion cooling system is besides grouped into open cycle system and closed cycle system. Turbo-Brayton refrigerator is a key component for closed cycle system. Those two cooling systems are focused in this article. And, each design and component of the cooling system is explained.

  20. Inhibition of calcium carbonate crystal growth by organic additives using the constant composition method in conditions of recirculating cooling circuits

    Science.gov (United States)

    Chhim, Norinda; Kharbachi, Chams; Neveux, Thibaut; Bouteleux, Céline; Teychené, Sébastien; Biscans, Béatrice

    2017-08-01

    The cooling circuits used in power plants are subject to mineral crystallization which can cause scaling on the surfaces of equipment and construction materials reducing their heat exchange efficiency. Precipitated calcium carbonate is the predominant mineral scale commonly observed in cooling systems. Supersaturation is the key parameter controlling the nucleation and growth of calcite in these systems. The present work focuses on the precipitation of calcite using the constant composition method at constant supersaturation, through controlled addition of reactants to a semi-batch crystallizer, in order to maintain constant solution pH. The determination of the thermodynamic driving force (supersaturation) was based on the relevant chemical equilibria, total alkalinity and calculation of the activity coefficients. Calcite crystallization rates were derived from the experiments performed at supersaturation levels similar to those found in industrial station cooling circuits. Several types of seeds particles were added into the aqueous solution to mimic natural river water conditions in terms of suspended particulate matters content, typically: calcite, silica or illite particles. The effect of citric and copolycarboxylic additive inhibitors added to the aqueous solution was studied. The calcium carbonate growth rate was reduced by 38.6% in the presence of the citric additive and a reduction of 92.7% was observed when the copolycarboxylic additive was used under identical experimental conditions. These results are explained by the location of the adsorbed inhibitor at the crystal surface and by the degree of chemical bonding to the surface.

  1. Emergency core cooling systems

    International Nuclear Information System (INIS)

    Kubokoya, Takashi; Okataku, Yasukuni.

    1984-01-01

    Purpose: To maintain the fuel soundness upon loss of primary coolant accidents in a pressure tube type nuclear reactor by injecting cooling heavy water at an early stage, to suppress the temperature of fuel cans at a lower level. Constitution: When a thermometer detects the temperature rise and a pressure gauge detects that the pressure for the primary coolants is reduced slightly from that in the normal operation upon loss of coolant accidents in the vicinity of the primary coolant circuit, heavy water is caused to flow in the heavy water feed pipeway by a controller. This enables to inject the heavy water into the reactor core in a short time upon loss of the primary coolant accidents to suppress the temperature rise in the fuel can thereby maintain the fuel soundness. (Moriyama, K.)

  2. The potential use of constructed wetlands in a recirculating aquaculture system for shrimp culture

    International Nuclear Information System (INIS)

    Lin, Y.-F.; Jing, S.-R.; Lee, D.-Y.

    2003-01-01

    Constructed wetlands improved water qualities and consequently increased the shrimp growth and survival in a recirculating system. - A pilot-scale constructed wetland unit, consisting of free water surface (FWS) and subsurface flow (SF) constructed wetlands arranged in series, was integrated into an outdoor recirculating aquaculture system (RAS) for culturing Pacific white shrimp (Litopenaeus vannamei). This study evaluated the performance of the wetland unit in treating the recirculating wastewater and examined the effect of improvement in water quality of the culture tank on the growth and survival of shrimp postlarvae. During an 80-day culture period, the wetland unit operated at a mean hydraulic loading rate of 0.3 m/day and effectively reduced the influent concentrations of 5-day biochemical oxygen demand (BOD 5 , 24%), suspended solids (SS, 71%), chlorophyll a (chl-a, 88%), total ammonium (TAN, 57%), nitrite nitrogen (NO 2 -N, 90%) and nitrate nitrogen (NO 3 -N, 68%). Phosphate (PO 4 -P) reduction was the least efficient (5.4%). The concentrations of SS, Chl-a, turbidity and NO 3 -N in the culture tank water in RAS were significantly (P≤0.05) lower than those in a control aquaculture system (CAS) that simulated static pond culture without wetland treatment. However, no significant difference (P≤0.05) in BOD 5 , TAN and NO 2 -N was found between the two systems. At the end of the study, the harvest results showed that shrimp weight and survival rate in the RAS (3.8±1.8 g/shrimp and 90%) significantly (P≤0.01) exceeded those in the CAS (2.3±1.5 g/shrimp and 71%). This study concludes that constructed wetlands can improve the water quality and provide a good culture environment, consequently increasing the shrimp growth and survival without water exchange, in a recirculating system

  3. The potential use of constructed wetlands in a recirculating aquaculture system for shrimp culture

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Y.-F.; Jing, S.-R.; Lee, D.-Y

    2003-05-01

    Constructed wetlands improved water qualities and consequently increased the shrimp growth and survival in a recirculating system. - A pilot-scale constructed wetland unit, consisting of free water surface (FWS) and subsurface flow (SF) constructed wetlands arranged in series, was integrated into an outdoor recirculating aquaculture system (RAS) for culturing Pacific white shrimp (Litopenaeus vannamei). This study evaluated the performance of the wetland unit in treating the recirculating wastewater and examined the effect of improvement in water quality of the culture tank on the growth and survival of shrimp postlarvae. During an 80-day culture period, the wetland unit operated at a mean hydraulic loading rate of 0.3 m/day and effectively reduced the influent concentrations of 5-day biochemical oxygen demand (BOD{sub 5}, 24%), suspended solids (SS, 71%), chlorophyll a (chl-a, 88%), total ammonium (TAN, 57%), nitrite nitrogen (NO{sub 2}-N, 90%) and nitrate nitrogen (NO{sub 3}-N, 68%). Phosphate (PO{sub 4}-P) reduction was the least efficient (5.4%). The concentrations of SS, Chl-a, turbidity and NO{sub 3}-N in the culture tank water in RAS were significantly (P{<=}0.05) lower than those in a control aquaculture system (CAS) that simulated static pond culture without wetland treatment. However, no significant difference (P{<=}0.05) in BOD{sub 5}, TAN and NO{sub 2}-N was found between the two systems. At the end of the study, the harvest results showed that shrimp weight and survival rate in the RAS (3.8{+-}1.8 g/shrimp and 90%) significantly (P{<=}0.01) exceeded those in the CAS (2.3{+-}1.5 g/shrimp and 71%). This study concludes that constructed wetlands can improve the water quality and provide a good culture environment, consequently increasing the shrimp growth and survival without water exchange, in a recirculating system.

  4. Advanced Horizontal Well Recirculation Systems for Geothermal Energy Recovery in Sedimentary and Crystalline Formations

    Energy Technology Data Exchange (ETDEWEB)

    Bruno, Mike S. [Terralog Technologies USA, Inc., Calgary (Canada); Detwiler, Russell L. [Terralog Technologies USA, Inc., Calgary (Canada); Lao, Kang [Terralog Technologies USA, Inc., Calgary (Canada); Serajian, Vahid [Terralog Technologies USA, Inc., Calgary (Canada); Elkhoury, Jean [Terralog Technologies USA, Inc., Calgary (Canada); Diessl, Julia [Terralog Technologies USA, Inc., Calgary (Canada); White, Nicky [Terralog Technologies USA, Inc., Calgary (Canada)

    2012-12-13

    There is increased recognition that geothermal energy resources are more widespread than previously thought, with potential for providing a significant amount of sustainable clean energy worldwide. Recent advances in drilling, completion, and production technology from the oil and gas industry can now be applied to unlock vast new geothermal resources, with some estimates for potential electricity generation from geothermal energy now on the order of 2 million megawatts. The primary objectives of this DOE research effort are to develop and document optimum design configurations and operating practices to produce geothermal power from hot permeable sedimentary and crystalline formations using advanced horizontal well recirculation systems. During Phase I of this research project Terralog Technologies USA and The University of California, Irvine (UCI), have completed preliminary investigations and documentation of advanced design concepts for paired horizontal well recirculation systems, optimally configured for geothermal energy recovery in permeable sedimentary and crystalline formations of varying structure and material properties. We have also identified significant geologic resources appropriate for application of such technology. The main challenge for such recirculation systems is to optimize both the design configuration and the operating practices for cost-effective geothermal energy recovery. These will be strongly influenced by sedimentary formation properties, including thickness and dip, temperature, thermal conductivity, heat capacity, permeability, and porosity; and by working fluid properties.

  5. Close loop gas recirculation and purification system for INO RPC system

    International Nuclear Information System (INIS)

    Joshi, A.V.; Kalmani, S.D.; Mondal, N.K.; Satyanarayana, B.; Verma, P.

    2013-01-01

    Close loop gas recirculation system (CLS) is designed to overcome problems. The present system is a pilot unit catering to about 12 RPC detectors of 2m ÃâĂŤ 2m size. The gas mixture is prepared in required concentration, in-situ, and circulated throughout the loop at controlled flow rates. The pressure band is adjusted to be within 20mm of water column. A Programmable Logic Controller (PLC) keeps track of pressure and flow rates, process sequence and safety conditions. The loss of gas is continuously monitored to assess effectiveness of CLS. The concentration of gas components in the mixtures is monitored by sampling through Residual Gas Analyzer (RGA). The RPC performance parameters, such as leakage current, noise rate, efficiency and cross-talk are monitored vis-a-vis CLS parameters. It has been found that RPC parameters respond in coordination with CLS functioning. Room pressure and temperature also seem to have influence on both of them

  6. STUDIES REGARDING THE PRESENCE OF THE PATHOGENS BACTERIA INTO A RECIRCULATING SYSTEM OF BELUGA STURGEON INTENSIVE REARING

    Directory of Open Access Journals (Sweden)

    ANGELICA DOCAN

    2008-10-01

    Full Text Available Recirculating aquaculture offers good potential for successful fish farming since is often independent of environmental conditions. Maintaining healthy fish in a recirculating system involves establishing adequate dissolved oxygen levels, removal of solid wastes, and sufficient ammonia nitrification to assure optimal rearing conditions. Neglecting these, the fish immune system will depress, the facultative pathogen germs will be able to provoke important disease outbreaks into cultured biomass, as was happened in our recirculating pilot system. In this study are presented the pathological aspects registered to the beluga sturgeon of 1 year, reared into our recirculating pilot system, pathological aspects generated by a haemorrhagic bacterial septicaemia which was manifested in the conditions of low concentrations of DO. The disease was diagnosed to the affected fish through anatomopathological and clinical exam, haematological exam and microbiological exam.

  7. Microbial populations causing off-flavour in recirculated aquaculture systems

    DEFF Research Database (Denmark)

    Lukassen, Mie Bech; Schramm, Edward; Nielsen, Jeppe Lund

    the distribution of geoA in more than 50 European and Brazilian aquaculture systems has allowed us to identify the diversity among geosmin-producing bacteria. The different populations of geosmin-producers were evaluated relative to plant design, environmental and operational parameters in full-scale aquaculture...... systems using multivariate statistics. The influencing parameters identified were subsequently validated by testing their gene expressions in well-controlled pilot scale aquaculture systems. The results show that the geoA gene is a relative well-conserved gene with limited horizontal gene transfer events...... phase. Furthermore, the gene expressions of the individual groups show positive correlations to the organic loading and presence of oxygen. The current study reveals the presence of important populations involved in geosmin production and which parameters are of importance for their presence...

  8. Internal dust recirculation system for a fluidized bed heat exchanger

    Science.gov (United States)

    Gamble, Robert L.; Garcia-Mallol, Juan A.

    1981-01-01

    A fluidized bed heat exchanger in which air is passed through a bed of particulate material containing fuel disposed in a housing. A steam/water natural circulation system is provided in a heat exchange relation to the bed and includes a steam drum disposed adjacent the bed and a tube bank extending between the steam drum and a water drum. The tube bank is located in the path of the effluent gases exiting from the bed and a baffle system is provided to separate the solid particulate matter from the effluent gases. The particulate matter is collected and injected back into the fluidized bed.

  9. Long term/low dose formalin exposure to small-scale recirculation aquaculture systems

    DEFF Research Database (Denmark)

    Pedersen, Lars-Flemming; Pedersen, Per Bovbjerg; Nielsen, Jeppe L.

    2010-01-01

    on a daily basis as compared to untreated systems. In systems intermittently treated with formalin, increased variation and minor reductions of ammonium and nitrite oxidation rates were observed. Nitrifying bacteria were screened by specific gene probes using fluorescence in situ hybridization and quantified...... Nitrobacter sp. was not detected. The relative abundances of AOB and NOB in the untreated system were generally higher compared to the system exposed to formalin. Low dose formalin in recirculated aquaculture systems proved to be a possible treatment strategy, as the effect on nitrification was minimal. Since...

  10. Proceedings: Cooling tower and advanced cooling systems conference

    International Nuclear Information System (INIS)

    1995-02-01

    This Cooling Tower and Advanced Cooling Systems Conference was held August 30 through September 1, 1994, in St. Petersburg, Florida. The conference was sponsored by the Electric Power Research Institute (EPRI) and hosted by Florida Power Corporation to bring together utility representatives, manufacturers, researchers, and consultants. Nineteen technical papers were presented in four sessions. These sessions were devoted to the following topics: cooling tower upgrades and retrofits, cooling tower performance, cooling tower fouling, and dry and hybrid systems. On the final day, panel discussions addressed current issues in cooling tower operation and maintenance as well as research and technology needs for power plant cooling. More than 100 people attended the conference. This report contains the technical papers presented at the conference. Of the 19 papers, five concern cooling tower upgrades and retrofits, five to cooling tower performance, four discuss cooling tower fouling, and five describe dry and hybrid cooling systems. Selected papers are indexed separately for inclusion in the Energy Science and Technology Database

  11. Forced draft wet cooling systems

    International Nuclear Information System (INIS)

    Daubert, A.; Caudron, L.; Viollet, P.L.

    1975-01-01

    The disposal of the heat released from a 1000MW power plant needs a natural draft tower of about 130m of diameter at the base, and 170m height, or a cooling system with a draft forced by about forty vans, a hundred meters in diameter, and thirty meters height. The plumes from atmospheric cooling systems form, in terms of fluid mechanics, hot jets in a cross current. They consist in complex flows that must be finely investigated with experimental and computer means. The study, currently being performed at the National Hydraulics Laboratory, shows that as far as the length and height of visible plumes are concerned, the comparison is favorable to some types of forced draft cooling system, for low and medium velocities, (below 5 or 6m/s at 10m height. Beyond these velocities, the forced draft sends the plume up to smaller heights, but the plume is generally more dilute [fr

  12. TPX heating and cooling system

    International Nuclear Information System (INIS)

    Kungl, D.J.; Knutson, D.S.; Costello, J.; Stoenescu, S.; Yemin, L.

    1995-01-01

    TPX, while having primarily super-conducting coils that do not require water cooling, still has very significant water cooling requirements for the plasma heating systems, vacuum vessel, plasma facing components, diagnostics, and ancillary equipment. This is accentuated by the 1000-second pulse requirement. Two major design changes, which have significantly affected the TPX Heating and Cooling System, have been made since the conceptual design review in March of 1993. This paper will discuss these changes and review the current status of the conceptual design. The first change involves replacing the vacuum vessel neutron shielding configuration of lead/glass composite tile by a much simpler and more reliable borated water shield. The second change reduces the operating temperature of the vacuum vessel from 150 C to ≥50 C. With this temperature reduction, all in-vessel components and the vessel will be supplied by coolant at a common ≥50 C inlet temperature. In all, six different heating and cooling supply requirements (temperature, pressure, water quality) for the various TPX components must be met. This paper will detail these requirements and provide an overview of the Heating and Cooling System design while focusing on the ramifications of the TPX changes described above

  13. Cooling system for auxiliary reactor component

    International Nuclear Information System (INIS)

    Fujihira, Tomoko.

    1991-01-01

    A cooling system for auxiliary reactor components comprises three systems, that is, two systems of reactor component cooling water systems (RCCW systems) and a high pressure component cooling water system (HPCCW system). Connecting pipelines having partition valves are intervened each in a cooling water supply pipeline to an emmergency component of each of the RCCW systems, a cooling water return pipeline from the emmergency component of each of the RCCW systems, a cooling water supply pipeline to each of the emmergency components of one of the RCCW system and the HPCCW system and a cooling water return pipeline from each of the emmergency components of one of the RCCW system and the HPCCW system. With such constitution, cooling water can be supplied also to the emmergency components in the stand-by system upon periodical inspection or ISI, thereby enabling to improve the backup performance of the emmergency cooling system. (I.N.)

  14. Systemic granuloma observed in Atlantic salmon Salmo salar raised to market size in a freshwater recirculation aquaculture system

    Science.gov (United States)

    Systemic granuloma was observed in sampled adult Atlantic salmon Salmo salar raised to harvest size in a freshwater recirculation aquaculture system. The prevalence of this condition was estimated at 10-20% of the population, with affected individuals grossly demonstrating pathology in varying degre...

  15. RECIRCULATING ACCELERATION

    International Nuclear Information System (INIS)

    BERG, J.S.; GARREN, A.A.; JOHNSTONE, C.

    2000-01-01

    This paper compares various types of recirculating accelerators, outlining the advantages and disadvantages of various approaches. The accelerators are characterized according to the types of arcs they use: whether there is a single arc for the entire recirculator or there are multiple arcs, and whether the arc(s) are isochronous or non-isochronous

  16. System for cooling a cabinet

    DEFF Research Database (Denmark)

    2015-01-01

    The present disclosure relates to a cooling system comprising an active magnetic regenerator having a cold side and a hot side, a hot side heat exchanger connected to the hot side of the magnetic regenerator, one or more cold side heat exchangers, and a cold store reservoir comprising a volume...

  17. Lamination cooling system formation method

    Science.gov (United States)

    Rippel, Wally E [Altadena, CA; Kobayashi, Daryl M [Monrovia, CA

    2009-05-12

    An electric motor, transformer or inductor having a cooling system. A stack of laminations have apertures at least partially coincident with apertures of adjacent laminations. The apertures define straight or angled cooling-fluid passageways through the lamination stack. Gaps between the adjacent laminations are sealed by injecting a heat-cured sealant into the passageways, expelling excess sealant, and heat-curing the lamination stack. Manifold members adjoin opposite ends of the lamination stack, and each is configured with one or more cavities to act as a manifold to adjacent passageway ends. Complex manifold arrangements can create bidirectional flow in a variety of patterns.

  18. Gas hydrate cool storage system

    Science.gov (United States)

    Ternes, M.P.; Kedl, R.J.

    1984-09-12

    The invention presented relates to the development of a process utilizing a gas hydrate as a cool storage medium for alleviating electric load demands during peak usage periods. Several objectives of the invention are mentioned concerning the formation of the gas hydrate as storage material in a thermal energy storage system within a heat pump cycle system. The gas hydrate was formed using a refrigerant in water and an example with R-12 refrigerant is included. (BCS)

  19. Reactor recirculation pump test loop

    International Nuclear Information System (INIS)

    Taka, Shusei; Kato, Hiroyuki

    1979-01-01

    A test loop for a reactor primary loop recirculation pumps (PLR pumps) has been constructed at Ebara's Haneda Plant in preparation for production of PLR pumps under license from Byron Jackson Pump Division of Borg-Warner Corporation. This loop can simulate operating conditions for test PLR pumps with 130 per cent of the capacity of pumps for a 1100 MWe BWR plant. A main loop, primary cooling system, water demineralizer, secondary cooling system, instrumentation and control equipment and an electric power supply system make up the test loop. This article describes the test loop itself and test results of two PLR pumps for Fukushima No. 2 N.P.S. Unit 1 and one main circulation pump for HAZ Demonstration Test Facility. (author)

  20. Reliability analysis of air recirculation and-refrigeration systems of Angra-1 reactor containment

    International Nuclear Information System (INIS)

    Fernandes Filho, T.L.

    1982-10-01

    A reliability analysis of the air refrigeration and recirculation containment systems (ARRCS) of Angra-1 nuclear power plants, were done. The fault tree analysis was used. The failure primary data were taken out of Wash-1400 and IEEE. These data were processed by these following computer codes : Prep-Kitt, Sample, Trebil, Cressex and Streusl for the two stages of ARRCS operation. The design bases accident studied was a LOCA (loss of coolant). The component that more contribution give to the non-availability of ARRCS is the motor of the ARRCS. (E.G.) [pt

  1. Effects of feed loading on nitrogen balances and fish performance in replicated recirculating aquaculture systems

    DEFF Research Database (Denmark)

    Pedersen, Lars-Flemming; Suhr, Karin Isabel; Dalsgaard, Anne Johanne Tang

    2012-01-01

    This study investigated the effects of applying four fixed feed loadings to three replicated recirculating aquaculture systems (RAS) on water quality changes, nitrogenous balances and growth performance of rainbow trout (Oncorhynchus mykiss).Feed loadings ranged from 1.6 to 6.3kgfeed/m3 make-up...... water, with a constant make-up water renewal of 4.7% of total water volume per day in all twelve RAS. Fish densities ranged from 14 to 92kg/m3 during the prolonged trial of 10weeks. Selected water quality parameters were measured during two intensive sampling campaigns, evaluating biofilter...

  2. A simple and low-cost recirculating aquaculture system for the production of arapaima juveniles

    OpenAIRE

    Burton, Andrew Mark; Moncayo Calderero, Edwin; Burgos Moran, Ricardo Ernesto; Anastacio Sánchez, Rogelio Lumbes; Avendaño Villamar, Ulises Tiberio; Ortega Torres, Nelson Guillermo

    2016-01-01

    A simple and low-cost recirculating system (RAS) for production of arapaima  (Arapaima gigas) juveniles is described. Twenty arapaima fry (mean 13.0 cm, 12.0 g) were housed in three production tanks and fed a high HUFA diet resulting in 90% of fry successfully progressing to juveniles (mean 17.4 cm long; 40.2 g). The fish were then reared for a further 72 days fed on commercial extruded pellet feed achieving a mean length of 42.6 cm and 656.6 g. The simple and low-cost RAS holds good potentia...

  3. Conceptual design of the cryogenic system and estimation of the recirculated power for CFETR

    Science.gov (United States)

    Liu, Xiaogang; Qiu, Lilong; Li, Junjun; Wang, Zhaoliang; Ren, Yong; Wang, Xianwei; Li, Guoqiang; Gao, Xiang; Bi, Yanfang

    2017-01-01

    The China Fusion Engineering Test Reactor (CFETR) is the next tokamak in China’s roadmap for realizing commercial fusion energy. The CFETR cryogenic system is crucial to creating and maintaining operational conditions for its superconducting magnet system and thermal shields. The preliminary conceptual design of the CFETR cryogenic system has been carried out with reference to that of ITER. It will provide an average capacity of 75 to 80 kW at 4.5 K and a peak capacity of 1300 kW at 80 K. The electric power consumption of the cryogenic system is estimated to be 24 MW, and the gross building area is about 7000 m2. The relationships among the auxiliary power consumed by the cryogenic system, the fusion power gain and the recirculated power of CFETR are discussed, with the suggestion that about 52% of the electric power produced by CFETR in phase II must be recirculated to run the fusion test reactor.

  4. Trough and pot crop systems with leaching recirculation and defoliation levels for mini tomatoes

    Directory of Open Access Journals (Sweden)

    Lais Perin

    2017-11-01

    Full Text Available The use of raw rice husk as substrate allows the use of crop systems that promote the recirculation of leachate in long crop cycles. Mini tomatoes present relatively low demand for photoassimilates. Thus, partial defoliation of the sympodium could benefit the crop without damage to the production or quality of the fruits. The objective of this work was to evaluate the plant growth, fruit yield and fruit quality of Cherry Hybrid Wanda and Grape Hybrid Dolcetto mini tomatoes cultivated in two recirculation crop systems (pots and troughs, using raw rice husk as substrate, under three defoliation conditions (without defoliation, removal of one and two leaves of the sympodium. The Cherry cultivar showed higher plant growth, fruit yield and mean fruit size. The Grape cultivar produced fruits with higher sugar concentration. For the Grape cultivar, the removal of one sympodium leaf did not affect the plant responses. However, for the Cherry cultivar, it was necessary to maintain the complete sympodium. The trough cultivation system improved plant growth and yield, whereas the pot system increased fruit sugar concentration.

  5. Cooling Tower Overhaul of Secondary Cooling System in HANARO

    Energy Technology Data Exchange (ETDEWEB)

    Park, Young Chul; Lee, Young Sub; Jung, Hoan Sung; Lim, In Chul [KAERI, Daejeon (Korea, Republic of)

    2007-07-01

    HANARO, an open-tank-in-pool type research reactor of 30 MWth power in Korea, has been operating normally since its initial criticality in February, 1995. For the last about ten years, A cooling tower of a secondary cooling system has been operated normally in HANARO. Last year, the cooling tower has been overhauled for preservative maintenance including fills, eliminators, wood support, water distribution system, motors, driving shafts, gear reducers, basements, blades and etc. This paper describes the results of the overhaul. As results, it is confirmed that the cooling tower maintains a good operability through a filed test. And a cooling capability will be tested when a wet bulb temperature is maintained about 28 .deg. C in summer and the reactor is operated with the full power.

  6. Corrosion products, activity transport and deposition in boiling water reactor recirculation systems

    International Nuclear Information System (INIS)

    Alder, H.P.; Buckley, D.; Grauer, R.; Wiedemann, K.H.

    1989-09-01

    The deposition of activated corrosion products in the recirculation loops of Boiling Water Reactors produces increased radiation levels which lead to a corresponding increase in personnel radiation dose during shut down and maintenance. The major part of this dose rate is due to cobalt-60. The following areas are discussed in detail: - the origins of the corrosion products and of cobalt-59 in the reactor feedwaters, - the consolidation of the cobalt in the fuel pin deposits (activation), - the release and transport of cobalt-60, - the build-up of cobalt-60 in the corrosion products in the recirculation loops. Existing models of the build-up of circuit radioactivity are discussed and the operating experiences from selected reactors are summarised. Corrosion chemistry aspects of the cobalt build-up in the primary circuit have already been studied on a broad basis and are continuing to be researched in a number of centers. The crystal chemistry of chromium-nickel steel corrosion products poses a number of yet unanswered questions. There are major loopholes associated with the understanding of activation processes of cobalt deposited on the fuel pins and in the mass transfer of cobalt-60. For these processes, the most important influence stems from factors associated with colloid chemistry. Accumulation of data from different BWRs contributes little to the understanding of the activity build-up. However, there are examples that the problem of activity build-up can be kept under control. Although many details for a quantitative understanding are still missing, the most important correlations are visible. The activity build-up in the BWR recirculation systems cannot be kept low by a single measure. Rather a whole series of measures is necessary, which influences not only cobalt-60 deposition but also plant and operation costs. (author) 26 figs., 13 tabs., 90 refs

  7. Effects of recirculation in a three-tank pilot-scale system for pharmaceutical removal with powdered activated carbon.

    Science.gov (United States)

    Kårelid, Victor; Larsson, Gen; Björlenius, Berndt

    2017-05-15

    The removal of pharmaceutically active compounds by powdered activated carbon (PAC) in municipal wastewater is a promising solution to the problem of polluted recipient waters. Today, an efficient design strategy is however lacking with regard to high-level overall, and specific, substance removal in the large scale. The performance of PAC-based removal of pharmaceuticals was studied in pilot-scale with respect to the critical parameters; contact time and PAC dose using one PAC product selected by screening in bench-scale. The goal was a minimum of 95% removal of the pharmaceuticals present in the evaluated municipal wastewater. A set of 21 pharmaceuticals was selected from an initial 100 due to their high occurrence in the effluent water of two selected wastewater treatment plants (WWTPs) in Sweden, whereof candidates discussed for future EU regulation directives were included. By using recirculation of PAC over a treatment system using three sequential contact tanks, a combination of the benefits of powdered and granular carbon performance was achieved. The treatment system was designed so that recirculation could be introduced to any of the three tanks to investigate the effect of recirculation on the adsorption performance. This was compared to use of the setup, but without recirculation. A higher degree of pharmaceutical removal was achieved in all recirculation setups, both overall and with respect to specific substances, as compared to without recirculation. Recirculation was tested with nominal contact times of 30, 60 and 120 min and the goal of 95% removal could be achieved already at the shortest contact times at a PAC dose of 10-15 mg/L. In particular, the overall removal could be increased even to 97% and 99%, at 60 and 120 min, respectively, when the recirculation point was the first tank. Recirculation of PAC to either the first or the second contact tank proved to be comparable, while a slightly lower performance was observed with recirculation to

  8. Information technology equipment cooling system

    Science.gov (United States)

    Schultz, Mark D.

    2014-06-10

    According to one embodiment, a system for removing heat from a rack of information technology equipment may include a sidecar indoor air to liquid heat exchanger that cools warm air generated by the rack of information technology equipment. The system may also include a liquid to liquid heat exchanger and an outdoor heat exchanger. The system may further include configurable pathways to connect and control fluid flow through the sidecar heat exchanger, the liquid to liquid heat exchanger, the rack of information technology equipment, and the outdoor heat exchanger based upon ambient temperature and/or ambient humidity to remove heat from the rack of information technology equipment.

  9. Atmospheric emissions from power plant cooling towers

    International Nuclear Information System (INIS)

    Micheletti, W.

    2006-01-01

    Power plant recirculated cooling systems (cooling towers) are not typically thought of as potential sources of air pollution. However, atmospheric emissions can be important considerations that may influence cooling tower design and operation. This paper discusses relevant U.S. environmental regulations for potential atmospheric pollutants from power plant cooling towers, and various methods for estimating and controlling these emissions. (orig.)

  10. Cooling system for superconducting magnet

    Science.gov (United States)

    Gamble, Bruce B.; Sidi-Yekhlef, Ahmed

    1998-01-01

    A cooling system is configured to control the flow of a refrigerant by controlling the rate at which the refrigerant is heated, thereby providing an efficient and reliable approach to cooling a load (e.g., magnets, rotors). The cooling system includes a conduit circuit connected to the load and within which a refrigerant circulates; a heat exchanger, connected within the conduit circuit and disposed remotely from the load; a first and a second reservoir, each connected within the conduit, each holding at least a portion of the refrigerant; a heater configured to independently heat the first and second reservoirs. In a first mode, the heater heats the first reservoir, thereby causing the refrigerant to flow from the first reservoir through the load and heat exchanger, via the conduit circuit and into the second reservoir. In a second mode, the heater heats the second reservoir to cause the refrigerant to flow from the second reservoir through the load and heat exchanger via the conduit circuit and into the first reservoir.

  11. Design of a recirculating radon progeny aerosol generation and animal exposure system

    International Nuclear Information System (INIS)

    Newton, G.J.; Cuddihy, R.G.; Yeh, H.C.; Barr, E.B.; Boecker, B.B.

    1988-01-01

    Inhalation studies are being conducted at ITRI using laboratory animals exposed to radon-222 progeny attached to vector aerosols that are typical of indoor environments. The purpose of these studies is to identify the cells at risk from inhaled radon progeny and their locations within the respiratory tract. These studies require exposures up to 1000 working level months (WLM) within a few hours. Thus, large amounts of radium-226 are needed to produce the gaseous radon-222. A once-through-exposure-system was considered to be impractical because of statutory discharge limitations and the large amounts of radium that would be required. Therefore, a recirculating exposure system was designed and constructed that removes the aerosol after passing through the exposure chambers and recirculates purified air and radon. The purified radon is mixed with freshly evolving radon from a radon generator and passed Into a reaction-aging chamber where attachment of radon progeny to the vector aerosol occurs. The design includes: (1) 50-200 mg radium-226 in a radon generator, (2) 40 L/min total flow rate, (3) CO 2 removal, (4) reconstitution of oxygen tension and water vapor content to atmospheric levels, and (5) a trap for radon gas. A radon progeny exposure concentration in the range of 4,000 to 50,000 WL is being produced. (author)

  12. Prediction of required ozone dosage for pilot recirculating aquaculture systems based on laboratory studies

    DEFF Research Database (Denmark)

    Spiliotopoulou, Aikaterini; Rojas-Tirado, Paula Andrea; Kaarsholm, Kamilla Marie Speht

    2017-01-01

    In recirculating aquaculture systems (RAS), the water quality changes continuously. Organic and inorganic compounds accumulates creating toxic conditions for the farmed organisms. Ozone improves water quality diminishing significantly both bacteria load and dissolved organic matter. However......, in a non-meticulously designed system, residual ozone might reach the culture tanks causing significant harm to cultured species or excess costs. The aim of the study was to predict the suitable ozone dosage in pilot RAS, for water treatment purposes, based on laboratory studies. The ozone effect on water...... quality of freshwater RAS and system’s ozone demand was investigated. Bench-scale ozonation experiments revealed the ozone demand of the system to be 180 mg O3/h. Three different ozone dosages were applied to four replicated systems with fixed feed loading (1.56 kg feed/m3 make up water). Results...

  13. Characteristic time series and operation region of the system of two tank reactors (CSTR) with variable division of recirculation stream

    International Nuclear Information System (INIS)

    Merta, Henryk

    2006-01-01

    The paper deals with a system of a cascade of two tank reactors, being characterized by the variable stream of recirculating fluid at each stage. The assumed mathematical model enables one to determine the system's dynamics for the case when there is no time delay and for the opposite case. The time series of the conversion degree and of the dimensionless fluid temperature, characteristic for the system considered as well as the operation regions-the latter-basing on Feingenbaum diagrams with respect to the division ratio of the recirculating stream are presented

  14. Mathematical modelling of nutrient balance of a goldfish (Carassius auratus Linn. recirculating aquaculture system (GRAS

    Directory of Open Access Journals (Sweden)

    Sudeep Puthravilakom Sadasivan Nair

    2010-08-01

    Full Text Available In the present study, a goldfish (Carassius auratus Linn. recirculating aquaculture system (GRAS has been developed. The GRAS consisted of a culture tank, a screen filter and a foam fractionator for removal of particulate and dissolved solids and a trickling filter for conversion of ammonium- and nitrite-nitrogen to relatively harmless nitrate-nitrogen. The culture of goldfish at a stocking density of 1.08 kg/m3 was continued for a period of two and half months. Based on mass balance analysis of ammonium- and nitrate-nitrogen and assuming the trickling filter to be a plug flow reactor, a model was formulated to determine the necessary recirculation flow rate at different times of culture for maintaining the major nutrients, viz., ammonium- and nitrate-nitrogen below their permissible limits. The model was calibrated and validated using the real time data obtained from the experimental run. The high values of coefficient of determination and low values of root mean square error show the effectiveness of the model.

  15. Pilot-scale cooling tower to evaluate corrosion, scaling, and biofouling control strategies for cooling system makeup water.

    Science.gov (United States)

    Chien, S H; Hsieh, M K; Li, H; Monnell, J; Dzombak, D; Vidic, R

    2012-02-01

    Pilot-scale cooling towers can be used to evaluate corrosion, scaling, and biofouling control strategies when using particular cooling system makeup water and particular operating conditions. To study the potential for using a number of different impaired waters as makeup water, a pilot-scale system capable of generating 27,000 kJ∕h heat load and maintaining recirculating water flow with a Reynolds number of 1.92 × 10(4) was designed to study these critical processes under conditions that are similar to full-scale systems. The pilot-scale cooling tower was equipped with an automatic makeup water control system, automatic blowdown control system, semi-automatic biocide feeding system, and corrosion, scaling, and biofouling monitoring systems. Observed operational data revealed that the major operating parameters, including temperature change (6.6 °C), cycles of concentration (N = 4.6), water flow velocity (0.66 m∕s), and air mass velocity (3660 kg∕h m(2)), were controlled quite well for an extended period of time (up to 2 months). Overall, the performance of the pilot-scale cooling towers using treated municipal wastewater was shown to be suitable to study critical processes (corrosion, scaling, biofouling) and evaluate cooling water management strategies for makeup waters of complex quality.

  16. Turbine airfoil with ambient cooling system

    Science.gov (United States)

    Campbell, Jr, Christian X.; Marra, John J.; Marsh, Jan H.

    2016-06-07

    A turbine airfoil usable in a turbine engine and having at least one ambient air cooling system is disclosed. At least a portion of the cooling system may include one or more cooling channels configured to receive ambient air at about atmospheric pressure. The ambient air cooling system may have a tip static pressure to ambient pressure ratio of at least 0.5, and in at least one embodiment, may include a tip static pressure to ambient pressure ratio of between about 0.5 and about 3.0. The cooling system may also be configured such that an under root slot chamber in the root is large to minimize supply air velocity. One or more cooling channels of the ambient air cooling system may terminate at an outlet at the tip such that the outlet is aligned with inner surfaces forming the at least one cooling channel in the airfoil to facilitate high mass flow.

  17. Reliability analysis of the recirculation phase of the safety injection system of Angra-1

    International Nuclear Information System (INIS)

    Rivera, R.R.J.M.

    1981-09-01

    The calculation of several reliability parameters-failure probability, unavailability and unreliability - of the recirculation phase of the safety injection system of Angra-1, was done. This system has two distinct modes of operation (short term and long term) which were fault tree analysed both separately and as a whole. To obtain quantitative results the computer codes SAMPLE and PRET-KITT were utilized. The former was used to consider the uncertainties in the failure data (drawn integrally from WASH-1400) and the latter to obtain time dependent unreliability values. Hardware failures and common-mode failures were considered. Altough the analysis methods employed here differ somewhat from those used in WASH-1400, the results which could be compared were found to have the order of magnitude. A viability study of some suggestions of system's modifications was performed, and it has shown that some significant reliability improvements can be achieved with reasonably simple changes. (Author) [pt

  18. Probiotic effects on cobia Rachycentron canadum larvae reared in a recirculating aquaculture system

    Directory of Open Access Journals (Sweden)

    M. Angélica Garrido-Pereira

    2014-11-01

    Full Text Available Cobia (Rachycentron canadum is a marine finfish with good potential for mariculture. This study analyzes the effects of probiotic Bacillus spp. on the performance of cobia larvae reared in a recirculating aquaculture system (RAS. Larvae were stocked into two independent RAS for 26 days after hatching. One of the systems (Probiotic treatment received the addition of a commercial probiotic consisting of B. subtilis, B. licheniformis and B. pumilus directly into the water and by live feed. Survival, final weight and water quality were not affected by probiotics. Results showed larvae of the probiotic treatment demonstrated a greater resistance to salinity stress. Immunohistochemical analysis showed a higher expression of CD4 in probiotic treatment. These results suggest that Bacillus spp. probiotics used in RAS have a potential stimulating impact on immune system differentiation and increases salinity stress resistance of cobia larvae.

  19. Emergency cooling system for a gas-cooled nuclear reactor

    International Nuclear Information System (INIS)

    Cook, R.K.; Burylo, P.S.

    1975-01-01

    The site of the gas-cooled reactor with direct-circuit gas turbine is preferably the sea coast. An emergency cooling system with safety valve and emergency feed-water addition is designed which affects at least a part of the reactor core coolant after leaving the core. The emergency cooling system includes a water emergency cooling circuit with heat exchanger for the core coolant. The safety valve releases water or steam from the emergency coolant circuit when a certain temperature is exceeded; this is, however, replaced by the emergency feed-water. If the gas turbine exhibits a high and low pressure turbine stage, which are flowed through by coolant one behind another, a part of the coolant can be removed in front of each part turbine by two valves and be added to the haet exchanger. (RW/LH) [de

  20. Simulations of floor cooling system capacity

    International Nuclear Information System (INIS)

    Odyjas, Andrzej; Górka, Andrzej

    2013-01-01

    Floor cooling system capacity depends on its physical and operative parameters. Using numerical simulations, it appears that cooling capacity of the system largely depends on the type of cooling loads occurring in the room. In the case of convective cooling loads capacity of the system is small. However, when radiation flux falls directly on the floor the system significantly increases productivity. The article describes the results of numerical simulations which allow to determine system capacity in steady thermal conditions, depending on the type of physical parameters of the system and the type of cooling load occurring in the room. Moreover, the paper sets out the limits of system capacity while maintaining a minimum temperature of the floor surface equal to 20 °C. The results are helpful for designing system capacity in different type of cooling loads and show maximum system capacity in acceptable thermal comfort condition. -- Highlights: ► We have developed numerical model for simulation of floor cooling system. ► We have described floor system capacity depending on its physical parameters. ► We have described floor system capacity depending on type of cooling loads. ► The most important in the obtained cooling capacities is the type of cooling loads. ► The paper sets out the possible maximum cooling floor system capacity

  1. Experimental assessment of an absorption cooling system utilizing a falling film absorber and generator

    International Nuclear Information System (INIS)

    Domínguez-Inzunza, L.A.; Hernández-Magallanes, J.A.; Soto, P.; Jiménez, C.; Gutiérrez-Urueta, G.; Rivera, W.

    2016-01-01

    Highlights: • A new prototype of an absorption cooling system using NH_3/LiNO_3 was developed. • Falling films shell and tubes heat exchangers were used as absorber and generator. • Evaporator temperatures as low as 4 °C were achieved. • The COP varied between 0.27 and 0.62 depending on the system temperatures. • A flow recirculation in the absorber was implemented showing an increase in COP. - Abstract: This study presents the results of the evaluation of an ammonia/lithium nitrate absorption cooling system. The generator and the absorber are shell and tubes falling film heat exchangers while the rest of the components are compact plate heat exchangers. A parametric study was carried out in order to determine the coefficients of performance and cooling capacities at different operating conditions. Also, an analysis was carried out to determine the influence of the absorber solution recirculation on the system performance. The generator temperatures varied between 80 °C and 100 °C, while the cooling water temperatures varied from 20 °C to 34 °C. Cooling capacities up to 4.5 kW and evaporator temperatures as low as 4 °C were achieved with the system. The internal coefficients of performance varied between 0.3 and 0.62 depending on the system operating temperatures. The system also showed good stability and repeatability.

  2. Fate of water borne therapeutic agents and associated effects on nitrifying biofilters in recirculating aquaculture systems

    DEFF Research Database (Denmark)

    Pedersen, Lars-Flemming

    of these agents on biofilter nitrification performance. All experiments were conducted through addition of chemical additives to closed pilot scale recirculating aquaculture systems (RAS) with fixed media submerged biofilters under controlled operating conditions with rainbow trout (Oncorhynchus mykiss...... to positively correlate to temperature, available biofilter surface-area, and the frequency of FA-exposure. Prolonged biofilter exposure to FA did not negatively affect nitrification, and could therefore be a method to optimize FA treatment in RAS and reduce FA discharge. HP degradation was rapid and could...... prolonged multiple HP dosages at 10 mg/L were found to inhibit nitrite oxidation in systems with low organic loading. PAA decay was found to be concentration-dependent. It had a considerable negative effect on nitrite oxidation over a prolonged period of time when applied at a dosage ≥2 mg/L. PAA and HP...

  3. Degradation and effect of hydrogen peroxide in small-scale recirculation aquaculture system biofilters

    DEFF Research Database (Denmark)

    Møller, Martin Sune; Arvin, Erik; Pedersen, Lars-Flemming

    2010-01-01

    From an environmental point of view, hydrogen peroxide (HP) has beneficial attributes compared with other disinfectants in terms of its ready degradation and neutral by-products. The rapid degradation of HP can, however, cause difficulties with regard to safe and efficient water treatment when...... applied in different systems. In this study, we investigated the degradation kinetics of HP in biofilters from water recirculating aquaculture systems (RAS). The potential effect of HP on the nitrification process in the biofilters was also examined. Biofilter elements from two different pilot-scale RAS......−1 maintained over 3 h had a moderate inhibitory effect on the biofilter elements from one of the RAS with relatively high organic loading, while the nitrification was severely inhibited in the pilot-scale biofilters from the other RAS with a relatively low organic loading. A pilot-scale RAS...

  4. Evaluation of a Shaker Dust Collector for Use in a Recirculating Ventilation System.

    Science.gov (United States)

    Peters, Thomas M; Sawvel, Russell A; Park, Jae Hong; Anthony, T Renée

    2015-01-01

    General ventilation with recirculated air may be cost-effective to control the concentration of low-toxicity, contaminants in workplaces with diffuse, dusty operations, such as in agriculture. Such systems are, however, rarely adopted with little evidence showing improved air quality and ability to operate under harsh conditions. The goal of this work was to examine the initial and long-term performance of a fabric-filter shaker dust collector (SDC) in laboratory tests and as deployed within a recirculating ventilation system in an agricultural building. In laboratory tests, collection efficiency and pressure drop were tracked over several filter loading cycles, and the recovery of filter capacity (pressure drop) from filter shaking was examined. Collection efficiencies of particles larger than 5 μm was high (>95%) even when the filter was pristine, showing effective collection of large particles that dominate inhalable concentrations typical of agricultural dusts. For respirable-sized particles, collection efficiencies were low when the filter was pristine (e.g., 27% for 1 μm) but much higher when a dust cake developed on the filter (>99% for all size particles), even after shaking (e.g., 90% for 1 μm). The first shake of a filter was observed to recovery a substantial fraction of filter capacity, with subsequent shakes providing little benefit. In field tests, the SDC performed effectively over a period of three months in winter when incorporated in a recirculating ventilation system of a swine farrowing room. Trends in collection efficiency and pressure drop with loading were similar to those observed in the laboratory with overall collection efficiencies high (>80%) when pressure drop exceeded 230 Pa, or 23% of the maximum loading recommended by the manufacturer. This work shows that the SDC can function effectively over the harsh winter in swine rearing operations. Together with findings of improved air quality in the farrowing room reported in a

  5. Environmental effects of cooling systems

    International Nuclear Information System (INIS)

    1980-01-01

    Since the International Atomic Energy Agency published in 1974 Thermal Discharges at Nuclear Power Stations (Technical Reports Series No.155), much progress has been made in the understanding of phenomena related to thermal discharges. Many studies have been performed in Member States and from 1973 to 1978 the IAEA sponsored a co-ordinated research programme on 'Physical and Biological Effects on the Environment of Cooling Systems and Thermal Discharges from Nuclear Power Stations'. Seven laboratories from Canada, the Federal Republic of Germany, India and the United States of America were involved in this programme, and a lot of new information has been obtained during the five years' collaboration. The progress of the work was discussed at annual co-ordination meetings and the results are presented in the present report. It complements the previous report mentioned above as it deals with several questions that were not answered in 1974. With the conclusion of this co-ordinated programme, it is obvious that some problems have not yet been resolved and that more work is necessary to assess completely the impact of cooling systems on the environment. It is felt, however, that the data gathered here will bring a substantial contribution to the understanding of the subject

  6. Evaporative cooling enhanced cold storage system

    Science.gov (United States)

    Carr, P.

    1991-10-15

    The invention provides an evaporatively enhanced cold storage system wherein a warm air stream is cooled and the cooled air stream is thereafter passed into contact with a cold storage unit. Moisture is added to the cooled air stream prior to or during contact of the cooled air stream with the cold storage unit to effect enhanced cooling of the cold storage unit due to evaporation of all or a portion of the added moisture. Preferably at least a portion of the added moisture comprises water condensed during the cooling of the warm air stream. 3 figures.

  7. Role of bacterial adhesion in the microbial ecology of biofilms in cooling tower systems.

    Science.gov (United States)

    Liu, Yang; Zhang, Wei; Sileika, Tadas; Warta, Richard; Cianciotto, Nicholas P; Packman, Aaron

    2009-01-01

    The fate of the three heterotrophic biofilm forming bacteria, Pseudomonas aeruginosa, Klebsiella pneumoniae and Flavobacterium sp. in pilot scale cooling towers was evaluated both by observing the persistence of each species in the recirculating water and the formation of biofilms on steel coupons placed in each cooling tower water reservoir. Two different cooling tower experiments were performed: a short-term study (6 days) to observe the initial bacterial colonization of the cooling tower, and a long-term study (3 months) to observe the ecological dynamics with repeated introduction of the test strains. An additional set of batch experiments (6 days) was carried out to evaluate the adhesion of each strain to steel surfaces under similar conditions to those found in the cooling tower experiments. Substantial differences were observed in the microbial communities that developed in the batch systems and cooling towers. P. aeruginosa showed a low degree of adherence to steel surfaces both in batch and in the cooling towers, but grew much faster than K. pneumoniae and Flavobacterium in mixed-species biofilms and ultimately became the dominant organism in the closed batch systems. However, the low degree of adherence caused P. aeruginosa to be rapidly washed out of the open cooling tower systems, and Flavobacterium became the dominant microorganism in the cooling towers in both the short-term and long-term experiments. These results indicate that adhesion, retention and growth on solid surfaces play important roles in the bacterial community that develops in cooling tower systems.

  8. Artificial liver support with the molecular adsorbent recirculating system: activation of coagulation and bleeding complications.

    Science.gov (United States)

    Bachli, Esther B; Schuepbach, Reto A; Maggiorini, Marco; Stocker, Reto; Müllhaupt, Beat; Renner, Eberhard L

    2007-05-01

    Numerous, mostly uncontrolled, observations suggest that artificial liver support with the Molecular Adsorbent Recirculating System (MARS) improves pathophysiologic sequelae and outcome of acute and acute-on-chronic liver failure. MARS is felt to be safe, but extracorporeal circuits may activate coagulation. To assess the frequency of and risk factors for activation of coagulation during MARS treatment. Retrospective analysis of coagulopathy/bleeding complications observed during 83 consecutive MARS sessions in 21 patients (11 men; median age 46 years; median three sessions per patient; median duration of session 8 h). Nine clinically relevant episodes of coagulopathy/bleeding were observed in eight patients, forced to premature cessation of MARS in seven and ended lethal in four. Four complications occurred during the first, five during later (third to seventh) MARS sessions and two bleeders tolerated further sessions without complications. Coagulation parameters worsened significantly also during MARS sessions not associated with bleeding (PMARS therapy, potentially leading to bleeding complications and mortality.

  9. Ozonation control and effects of ozone on water quality in recirculating aquaculture systems

    DEFF Research Database (Denmark)

    Spiliotopoulou, Aikaterini; Rojas-Tirado, Paula Andrea; Chetri, Ravi K.

    2018-01-01

    To address the undesired effect of chemotherapeutants in aquaculture, ozone has been suggested as an alternative to improve water quality. To ensure safe and robust treatment, it is vital to define the ozone demand and ozone kinetics of the specific water matrix to avoid ozone overdose. Different...... ozone dosages were applied to water in freshwater recirculating aquaculture systems (RAS). Experiments were performed to investigate ozone kinetics and demand, and to evaluate the effects on the water quality, particularly in relation to fluorescent organic matter. This study aimed at predicting...... a suitable ozone dosage for water treatment based on daily ozone demand via laboratory studies. These ozone dosages will be eventually applied and maintained at these levels in pilot-scale RAS to verify predictions. Selected water quality parameters were measured, including natural fluorescence and organic...

  10. Solar-powered cooling system

    Science.gov (United States)

    Farmer, Joseph C.

    2015-07-28

    A solar-powered adsorption-desorption refrigeration and air conditioning system that uses nanostructural materials such as aerogels, zeolites, and sol gels as the adsorptive media. Refrigerant molecules are adsorbed on the high surface area of the nanostructural material while the material is at a relatively low temperature, perhaps at night. During daylight hours, when the nanostructural materials is heated by the sun, the refrigerant are thermally desorbed from the surface of the aerogel, thereby creating a pressurized gas phase in the vessel that contains the aerogel. This solar-driven pressurization forces the heated gaseous refrigerant through a condenser, followed by an expansion valve. In the condenser, heat is removed from the refrigerant, first by circulating air or water. Eventually, the cooled gaseous refrigerant expands isenthalpically through a throttle valve into an evaporator, in a fashion similar to that in more conventional vapor recompression systems.

  11. Effects of exhaust gas recirculation on the thermal efficiency and combustion characteristics for premixed combustion system

    International Nuclear Information System (INIS)

    Yu, Byeonghun; Kum, Sung-Min; Lee, Chang-Eon; Lee, Seungro

    2013-01-01

    In this research, a boiler in a premixed combustion system used to achieve exhaust gas recirculation was investigated as a way to achieve high thermal efficiencies and low pollutant emissions. The effects of various exhaust gas recirculation (EGR) ratios, equivalence ratios and boiler capacities on thermal efficiency, NO x and CO emissions and the flame behavior on the burner surface were examined both experimentally and numerically. The results of the experiments showed that when EGR was used, the NO x and CO concentrations decreased and the thermal efficiency increased. In the case of a 15% EGR ratio at an equivalence ratio of 0.90, NO x concentrations were found to be smaller than for the current operating condition of the boiler, and the thermal efficiency was approximately 4.7% higher. However, unlike NO x concentrations, although the EGR ratio was increased to 20% at an equivalence ratio of 0.90, the CO concentration was higher than in the current operating condition of the boiler. From the viewpoint of burner safety, the red glow on the burner surface was noticeably reduced when EGR was used. These results confirmed that the EGR method is advantageous from the standpoint of reducing emission concentrations and ensuring burner safety. -- Highlights: ► The premixed boiler system applied EGR was investigated to achieve high thermal efficiencies and low pollutant emissions. ► Thermal efficiency and emission characteristics were examined with EGR ratios, equivalence ratios and boiler capacities. ► EGR method is advantageous from the standpoint of reducing emission concentrations and ensuring burner safety.

  12. Abnormal swimming behavior and increased deformities in rainbow trout Oncorhynchus mykiss cultured in low exchange water recirculation aquaculture systems

    Science.gov (United States)

    Two studies were conducted to determine if accumulating water quality parameters would negatively impact rainbow trout Oncorhynchus mykiss health and welfare within water recirculation aquaculture systems (WRAS) that were operated at low and near-zero water exchange, with and without ozonation, and ...

  13. The effects of ozonation on select waterborne steroid hormones in recirculation aquaculture systems containing sexually mature Atlantic salmon Salmo salar

    Science.gov (United States)

    A controlled 3-month study was conducted in 6 replicated water recirculation aquaculture systems (RAS) containing a mixture of sexually mature and immature Atlantic salmon Salmo salar to determine whether water ozonation is associated with a reduction in waterborne hormones. Post-smolt Atlantic salm...

  14. Membrane biological reactors to remove nitrate, digest biosolids, and eliminate water flushing requirements within replicated recirculation systems culturing rainbow trout

    Science.gov (United States)

    Nutrients, particularly nitrate (NO3), can accumulate to very high levels within low exchange recirculation aquaculture systems (RAS) and negatively impact a number of cultured species. To prevent the harmful effects of nitrate accumulation and to dispose of concentrated waste biosolids, many RAS ar...

  15. Evaluation of a low-head recirculating aquaculture system used for rearing Florida pompano to market size

    Science.gov (United States)

    A low-head recirculating aquaculture system (RAS) was evaluated for the production Florida pompano Trachinotus carolinus from juvenile to market size. The RAS consisted of three dual-drain, 3-m diameter culture tanks of 7.8 m3 volume each, two 0.7-m3 moving bed bioreactors filled 67% with K1 kaldnes...

  16. Production characteristics and body composition of juvenile cobia fed three different commercial diets in recirculating aquaculture systems

    Science.gov (United States)

    The effect of feeding three commercial diets on production characteristics and body composition of juvenile cobia Rachycentron canadum reared using recirculating aquaculture systems (RAS) was evaluated in a 56 d growth trial. Juvenile cobia (29.2 +/= 0.7 g, mean weight +/= SE) were stocked into thr...

  17. The impact of water exchange rate on the health and performance of rainbow trout Oncorhynchus mykiss in recirculation aquaculture systems

    Science.gov (United States)

    Fish mortality in recirculating aquaculture systems (RAS) has been observed by the authors to increase when RAS are managed at low makeup water exchange rates with relatively high feed loading. The precise etiology of this elevated mortality was unknown, all typical water quality parameters were wit...

  18. Cortisol and testosterone accumulation in a low pH recirculating aquaculture system for rainbow trout (Oncorhynchus mykiss)

    NARCIS (Netherlands)

    Mota, Vasco C.; Martins, Catarina I.M.; Eding, Ep H.; Canário, Adelino V.M.; Verreth, Johan A.J.

    2017-01-01

    Steroids accumulate in recirculating aquaculture system (RAS), although explanatory factors for such accumulation are still poorly explored. This study investigated the effect of water exchange rate and pH in six replicated RAS on the concentration of the stress hormone cortisol in rainbow trout

  19. Development in cooling water intake and outfall systems for atomic or steam power stations

    International Nuclear Information System (INIS)

    Wada, Akira

    1987-01-01

    The condenser cooling water channel, in its functional aspects, is an important structure for securing a stable supply of cooling water. In its design it is necessary to give a thorough-going study to a reduction of ranges affected by discharged warm water and minimizing the effect of discharged water on navigating ships, and in its functional aspects as a structure for power generation, avoiding the recirculation of discharged warm water as well as to maintaining the operation of power stations in case of abnormalities (concentration of dirts owing to typhoons and floods, outbreak of a large amount of jellyfishes, etc.), and all these aspects must be reflected in the design of cooling water channel systems. In this paper, the present situation relating to the design of cooling water intake and outfall systems in Japan is discussed. (author). 10 figs

  20. Dry and mixed air cooling systems

    International Nuclear Information System (INIS)

    Gutner, Gidali.

    1975-01-01

    The various dry air cooling systems now in use or being developed are classified. The main dimensioning parameters are specified and the main systems already built are given with their characteristics. The available data allow dry air cooling to be situated against the other cooling modes and so specify the aim of the research or currently developed works. Some systems at development stages are briefly described. The interest in mixed cooling (assisted draft) and the principal available systems is analyzed. A program of research is outlined [fr

  1. A combined capillary cooling system for cooling fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Ana Paula; Pelizza, Pablo Rodrigo; Galante, Renan Manozzo; Bazzo, Edson [Universidade Federal de Santa Catarina (LabCET/UFSC), Florianopolis, SC (Brazil). Dept. de Engenharia Mecanica. Lab. de Combustao e Engenharia de Sistemas Termicos], Emails: ana@labcet.ufsc.br, pablo@labcet.ufsc.br, renan@labcet.ufsc.br, ebazzo@emc.ufsc.br

    2010-07-01

    The operation temperature control has an important influence over the PEMFC (Proton Exchange Membrane Fuel Cell) performance. A two-phase heat transfer system is proposed as an alternative for cooling and thermal control of PEMFC. The proposed system consists of a CPL (Capillary Pumped Loop) connected to a set of constant conductance heat pipes. In this work ceramic wick and stainless mesh wicks have been used as capillary structure of the CPL and heat pipes, respectively. Acetone has been used as the working fluid for CPL and deionized water for the heat pipes. Experimental results of three 1/4 inch stainless steel outlet diameter heats pipes and one CPL have been carried out and presented in this paper. Further experiments are planned coupling the proposed cooling system to a module which simulates the fuel cell. (author)

  2. Developments in power plant cooling systems

    International Nuclear Information System (INIS)

    Agarwal, N.K.

    1993-01-01

    A number of cooling systems are used in the power plants. The condenser cooling water system is one of the most important cooling systems in the plant. The system comprises a number of equipment. Plants using sea water for cooling are designed for the very high corrosion effects due to sea water. Developments are taking place in the design, materials of construction as well as protection philosophies for the various equipment. Power optimisation of the cycle needs to be done in order to design an economical system. Environmental (Protection) Act places certain limitations on the effluents from the plant. An attempt has been made in this paper to outline the developing trends in the various equipment in the condenser cooling water systems used at the inland as well as coastal locations. (author). 5 refs., 6 refs

  3. Conduction cooling systems for linear accelerator cavities

    Science.gov (United States)

    Kephart, Robert

    2017-05-02

    A conduction cooling system for linear accelerator cavities. The system conducts heat from the cavities to a refrigeration unit using at least one cavity cooler interconnected with a cooling connector. The cavity cooler and cooling connector are both made from solid material having a very high thermal conductivity of approximately 1.times.10.sup.4 W m.sup.-1 K.sup.-1 at temperatures of approximately 4 degrees K. This allows for very simple and effective conduction of waste heat from the linear accelerator cavities to the cavity cooler, along the cooling connector, and thence to the refrigeration unit.

  4. Integrated Multi-Trophic Recirculating Aquaculture System for Nile Tilapia (Oreochlomis niloticus

    Directory of Open Access Journals (Sweden)

    Puchong Sri-uam

    2016-06-01

    Full Text Available Three densities of the sex-reversed male Nile tilapia, Oreochromis niloticus (20, 25, 50 fish/m3 were cultivated in an integrated multi-trophic recirculating aquaculture system (IMRAS that involves the ecological relationship between several living organisms, i.e., phytoplankton, zooplankton, and aquatic plants. The results indicated that, by providing proper interdependency between various species of living organisms, the concentrations of ammonia, nitrite, nitrate, and phosphate in the system were maintained below dangerous levels for Nile tilapia throughout the cultivation period. The highest wet weight productivity of Nile tilapia of 11 ± 1 kg was achieved at a fish density of 50 fish/m3. The aquatic plants in the treatment tank could effectively uptake the unwanted nitrogen (N and phosphorus (P compounds with the highest removal efficiencies of 9.52% and 11.4%, respectively. The uptake rates of nitrogen and phosphorus by aquatic plants could be ranked from high to low as: Egeria densa > Ceratophyllum demersum > Vallisneria spiralis and Vallisneria americana > Hygrophila difformis. The remaining N was further degraded through nitrification process, whereas the remaining P could well precipitate in the soil sediment in the treatment tank.

  5. Hot gas path component cooling system

    Science.gov (United States)

    Lacy, Benjamin Paul; Bunker, Ronald Scott; Itzel, Gary Michael

    2014-02-18

    A cooling system for a hot gas path component is disclosed. The cooling system may include a component layer and a cover layer. The component layer may include a first inner surface and a second outer surface. The second outer surface may define a plurality of channels. The component layer may further define a plurality of passages extending generally between the first inner surface and the second outer surface. Each of the plurality of channels may be fluidly connected to at least one of the plurality of passages. The cover layer may be situated adjacent the second outer surface of the component layer. The plurality of passages may be configured to flow a cooling medium to the plurality of channels and provide impingement cooling to the cover layer. The plurality of channels may be configured to flow cooling medium therethrough, cooling the cover layer.

  6. Synergistic Effects of Micro-electrolysis-Photocatalysis on Water Treatment and Fish Performance in Saline Recirculating Aquaculture System

    OpenAIRE

    Ye, Zhangying; Wang, Shuo; Gao, Weishan; Li, Haijun; Pei, Luowei; Shen, Mingwei; Zhu, Songming

    2017-01-01

    A new physico-chemical process for TAN (total ammonia nitrogen) removal and disinfection is introduced in saline recirculating aquaculture system (RAS), in which the biofilter is replaced with an integrated electrolysis cell and an activated carbon filter. The electrolysis cell which is based on micro current electrolysis combined with UV-light was self-designed. After the fundamental research, a small pilot scale RAS was operated for 30 days to verify the technical feasibility. The system wa...

  7. Hematologic and plasma chemistry RIs for cultured Striped catfish (Pangasius hypophthalmus) in recirculating aquaculture systems.

    Science.gov (United States)

    Galagarza, Oscar A; Kuhn, David D; Smith, Stephen A; Hrubec, Terry C

    2017-09-01

    Striped catfish (Pangasius hypophthalmus) is a valuable aquaculture fish species produced primarily in Southeast Asia. In the United States, it is bred as an ornamental species. Striped catfish has high productivity and great demand in numerous countries around the world, yet little is known about its normal physiology. The objective of this study was to establish hematologic and blood chemistry RIs for healthy juvenile Striped catfish. Blood samples were collected from 70 Striped catfish raised in recirculating aquaculture systems. Whole blood and plasma samples were analyzed for multiple hematologic and chemistry variables using standard techniques. The RIs for hematology were as follows: PCV 23.5-35.9%, MCV 106.3-156.6 fL, RBC count 1.79-2.75 × 10 6 cells/μL, thrombocytes 26,318-73,333 cells/μL, total WBC count 36,294-94,286 cells/μL, total lymphocytes 18,997-59,998 cells/μL, small lymphocytes 13,763-51,490 cells/μL, large lymphocytes 715-21,200 cells/μL, granulocytes 4504-18,291 cells/μL, and monocytes 0-7549 cells/μL. Plasma chemistry RIs were the following: ALP 32.7-74.6 U/L, AST 20.3-1235.8 U/L, sodium 135.2-147.7 mmol/L, potassium 3.3-5.0 mmol/L, chloride 120.1-133.6 mmol/L, calcium 2.7-3.6 mmol/L, magnesium 0.9-1.3 mmol/L, phosphorous 1.4-2.7 mmol/L, glucose 4.6-7.6 mmol/L, cholesterol 2.8-5.3 mmol/L, total protein 30-42 g/L, albumin 7-11 g/L, globulin 22-32 g/L, albumin:globulin ratio 0.27-0.37, creatinine 0-8 μmol/L, and osmolality 251.8-327.9 mOsm/kg. Reference intervals reported here can help veterinarians and fish health specialists monitor the health status of Striped catfish under recirculating aquaculture conditions for research, exhibition, and production purposes. © 2017 American Society for Veterinary Clinical Pathology.

  8. Impact of water boundary layer diffusion on the nitrification rate of submerged biofilter elements from a recirculating aquaculture system

    DEFF Research Database (Denmark)

    Prehn, Jonas; Waul, Christopher Kevin; Pedersen, Lars-Flemming

    2012-01-01

    Total ammonia nitrogen (TAN) removal by microbial nitrification is an essential process in recirculating aquaculture systems (RAS). In order to protect the aquatic environment and fish health, it is important to be able to predict the nitrification rates in RAS’s. The aim of this study was to det...... biofilters. The results may thus have practical implications in relation to the design, operational strategy of RAS biofilters and how to optimize TAN removal in fixed film biofilter systems......Total ammonia nitrogen (TAN) removal by microbial nitrification is an essential process in recirculating aquaculture systems (RAS). In order to protect the aquatic environment and fish health, it is important to be able to predict the nitrification rates in RAS’s. The aim of this study...

  9. The development of air cooled condensation systems

    International Nuclear Information System (INIS)

    Bodas, J.

    1990-01-01

    EGI - Contracting/Engineering has had experience with the development of air cooled condensing systems since the 1950's. There are two accepted types of dry cooling systems,the direct and the indirect ones. Due to the fact that the indirect system has several advantages over the direct one, EGI's purpose was to develop an economic, reliable and efficient type of indirect cooling system, both for industrial and power station applications. Apart from system development, the main components of dry cooling plant have been developed as well. These are: the water-to-air heat exchangers; the direct contact (DC, or jet) condenser; the cooling water circulating pumps and recovery turbines; and the peak cooling/preheating units. As a result of this broad development work which was connected with intensive market activity, EGI has supplied about 50% of the dry cooling plants employed for large power stations all over the world. This means that today the cumulated capacity of power units using Heller type dry cooling systems supplied and contracted by EGI is over 6000 MW

  10. Conditioning of broodstock of tiger grouper, Epinephelus fuscoguttatus, in a recirculating aquaculture system

    Directory of Open Access Journals (Sweden)

    Saleem Mustafa

    2015-11-01

    Full Text Available Closing the cycle of commercial species of fish in a recirculating aquaculture system is gaining importance for a number of practical advantages. Founder broodstock originating from the wild population is conditioned to live in hatchery tanks under suitable environmental and feeding conditions and is induced to breed. The juveniles are grown to maturity and facilitated to spawn in captivity to close the life cycle in the hatchery. This experiment was carried out on tiger grouper (Epinephelus fuscoguttatus. After preliminary observations, it was possible to identify appropriate environmental conditions in terms of water quality parameters, volume of broodstock tanks and ration. Growth was nearly isometric (growth exponent = 2.9185 and the condition factor = 1.86. This reflected good management conditions. Cues that trigger sex reversal in this protogynous fish in the hatchery were different from those that operate in nature. It appears that the differentiation of some individuals of a cohort into male sex is linked to socio-demographic cues as well as internal condition of the fish because it related to age and physiological condition. This view was reinforced by a lack of response in young fish to similar cues. The information generated through this study defines what is required for optimum conditioning of tiger grouper broodstock and explains the cues involved in sex differentiation.

  11. A study on the optimal hydraulic loading rate and plant ratios in recirculation aquaponic system.

    Science.gov (United States)

    Endut, Azizah; Jusoh, A; Ali, N; Wan Nik, W B; Hassan, A

    2010-03-01

    The growths of the African catfish (Clarias gariepinus) and water spinach (Ipomoea aquatica) were evaluated in recirculation aquaponic system (RAS). Fish production performance, plant growth and nutrient removal were measured and their dependence on hydraulic loading rate (HLR) was assessed. Fish production did not differ significantly between hydraulic loading rates. In contrast to the fish production, the water spinach yield was significantly higher in the lower hydraulic loading rate. Fish production, plant growth and percentage nutrient removal were highest at hydraulic loading rate of 1.28 m/day. The ratio of fish to plant production has been calculated to balance nutrient generation from fish with nutrient removal by plants and the optimum ratio was 15-42 gram of fish feed/m(2) of plant growing area. Each unit in RAS was evaluated in terms of oxygen demand. Using specified feeding regime, mass balance equations were applied to quantify the waste discharges from rearing tanks and treatment units. The waste discharged was found to be strongly dependent on hydraulic loading rate. 2009 Elsevier Ltd. All rights reserved.

  12. Broodstock management of the fine flounder Paralichthys adspersus (Steindachner, 1867 using recirculating aquaculture systems

    Directory of Open Access Journals (Sweden)

    Lili Carrera

    2013-03-01

    Full Text Available The present study describes the methodology used at IMARPE for the capture, acclimation and management of P. adspersus broodstock using recirculating aquaculture systems (RAS. RAS improved the water quality and maintained the environmental parameters during the acclimation period, temperature (17.2±1°C, oxygen (8.1±0.7 mg L-1, pH (7.3±0.2, ammonia (0.004±0.003 mg L-1, nitrite (0.52±0.2 mg L-1 and nitrate (3.45±2.6 mg L-1. Fish began to be fed normally from day 15 post-capture, once or twice a day using live fish (Odonthestes regia regia, Mugil cephalus, crustacean (Emerita analoga, fresh food (Engraulis ringens and Dosidicus gigas and artificial feed. A significant loss in the weight of the fish was registered during the first days of captivity, followed by a continuous increase in both sexes. The specific growth rate was positive from the third month of captivity, being the relative growth rate 24.5% and 16.2% in August 2010 in males and females, respectively. Different internal and external parasites were detected in the fish, being Entobdella sp. and Philometra sp. the prevailing parasites observed during samplings.

  13. Performance Study of Ceramic Filter Module in Recirculated Aquaculture System (RAS)

    Science.gov (United States)

    Ng, L. Y.; Ng, C. Y.

    2017-06-01

    The growth of world population has led to significant increase in seafood demand over the world. Aquaculture has been widely accepted by many countries to increase the seafood production owing to the decline of natural seafood resources. The aquaculture productivity, however, is directly linked to the pond water quality. In this study, attempts were made to employ ceramic micro-filter to improve the pond water quality through filtration processes. There were two batches of filtration processes, short term (1 hour) and long term (48 hours). Significant improvements on real pond water quality were recorded through the short term microfiltration process, which reduced turbidity (96%), total suspended solids (TSS) (80%), biochemical oxygen demand (BOD) (72%), chemical oxygen demand (COD) (55%), ammonia (60%), nitrate (96%) and phosphorus (83%). The long term filtration process also showed high efficiency in the removal of solid particle and organic matters. The results showed that all of the parameters were successfully reduced to acceptable ranges (turbidityfiltered pond water. Current study showed that the microfiltration using ceramic micro-filter has high potential to be used in recirculating aquaculture system throughout the aquaculture activities in order to maintain the pond water quality, thus, increase the survival rate of cultured species.

  14. Increasing the electric efficiency of a fuel cell system by recirculating the anodic offgas

    Science.gov (United States)

    Heinzel, A.; Roes, J.; Brandt, H.

    The University of Duisburg-Essen and the Center for Fuel Cell Technology (ZBT Duisburg GmbH) have developed a compact multi-fuel steam reformer suitable for natural gas, propane and butane. Fuel processor prototypes based on this concept were built up in the power range from 2.5 to 12.5 kW thermal hydrogen power for different applications and different industrial partners. The fuel processor concept contains all the necessary elements, a prereformer step, a primary reformer, water gas shift reactors, a steam generator, internal heat exchangers, in order to achieve an optimised heat integration and an external burner for heat supply as well as a preferential oxidation step (PrOx) as CO purification. One of the built fuel processors is designed to deliver a thermal hydrogen power output of 2.5 kW according to a PEM fuel cell stack providing about 1 kW electrical power and achieves a thermal efficiency of about 75% (LHV basis after PrOx), while the CO content of the product gas is below 20 ppm. This steam reformer has been combined with a 1 kW PEM fuel cell. Recirculating the anodic offgas results in a significant efficiency increase for the fuel processor. The gross efficiency of the combined system was already clearly above 30% during the first tests. Further improvements are currently investigated and developed at the ZBT.

  15. Commercial production of tiger puffer ( Takifugu rubripes) in winter using a recirculating aquaculture system

    Science.gov (United States)

    Lin, Zhongling; Wang, Hua; Yu, Chunyan; Lv, Fenghe; Liu, Hengming; Zhang, Tao

    2017-02-01

    Tiger puffer ( Takifugu rubripes) is a promising species for aquaculture production because of its high value and limited supply. However, in the north of China, using sea cages to culture this species in winter is hampered by the fact that the seawater temperature is extremely low. Here, a large scale commercial production of tiger puffer has been successfully realized using a recirculating aquaculture system (RAS) from 3 October 2012 to 31 May 2013. The RAS was comprised of nine culture tanks (total water volume 200 m3) and stocked with approximately a total of 14400 fish (initial mean weight 160 g). The tiger puffer was hand-fed at a rate of 0.7% of total body weight per day, and the feed conversion rate was (1.21 ± 0.3) kg kg-1. The recycle water in RAS was treated by a sieve bend screen, a foam fractionator, a submerged biofilter, an UV sterilizer and a submersible aerator. During the whole culture period, an excellent water quality control was achieved in RAS. At the end of this experiment, the survival rate of tiger puffer was more than 98%. The final tank densities averaged 31.2 kg m-3, and the final individual mean weight was 440 g.

  16. [Responses of antioxidation system of Cynodon dactylon to recirculated landfill leachate irrigation].

    Science.gov (United States)

    Wang, Ruyi; He, Pinjing; Shao, Liming; Zhang, Bin; Li, Guojian

    2005-05-01

    With pot experiment, this paper studied the membrane lipid peroxidation and the variations of antioxidation system in Cynodon dactylon under recirculated landfill leachate irrigation. The results showed that when irrigated with low dilution ratio ( 25%), there existed an obvious negative fect on Cynodon dactylon, i.e., the chlorophyll a/b ratio decreased, while cell membrane permeability and MDA and H2O2 contents increased, which meant that the membrane lipid peroxidation was accelerated. The contents antioxidants AsA, GSH and Car also showed the similar trend, i.e., they increased with increasing leachate dilution ratio when irrigated with low dilution ratio leachate, but decreased under medium or high dilution ratio leachate irrigation. Among three test anti-oxidative enzymes, SOD and POD activities showed a similar change test antioxidants, and POD activity was more sensitive, while CAT activity was on the contrary. The contents test antioxidants and the activities of SOD and POD were negatively and significantly correlated to MDA content, indicating that they might play an important role in preventing Cynodon dactylon from cell membrane lipid peroxdation.

  17. Intestinal microbiota of healthy and unhealthy Atlantic salmon Salmo salar L. in a recirculating aquaculture system

    Science.gov (United States)

    Wang, Chun; Sun, Guoxiang; Li, Shuangshuang; Li, Xian; Liu, Ying

    2018-03-01

    The present study sampled the intestinal content of healthy and unhealthy Atlantic salmon ( Salmo salar L.), the ambient water of unhealthy fish, and the biofilter material in the recirculating aquaculture system (RAS) to understand differences in the intestinal microbiota. The V4-V5 regions of the prokaryotic 16S rRNA genes in the samples were analyzed by MiSeq high-throughput sequencing. The fish were adults with no differences in body length or weight. Representative members of the intestinal microbiota were identified. The intestinal microbiota of the healthy fish included Proteobacteria (44.33%), Actinobacteria (17.89%), Bacteroidetes (15.25%), and Firmicutes (9.11%), among which the families Micrococcaceae and Oxalobacteraceae and genera Sphingomonas, Streptomyces, Pedobacter, Janthinobacterium, Burkholderia, and Balneimonas were most abundant. Proteobacteria (70.46%), Bacteroidetes (7.59%), and Firmicutes (7.55%) dominated the microbiota of unhealthy fish, and Chloroflexi (2.71%), and Aliivibrio and Vibrio as well as genera in the family Aeromonadaceae were most strongly represented. Overall, the intestinal hindgut microbiota differed between healthy and unhealthy fish. This study offers a useful tool for monitoring the health status of fish and for screening the utility of probiotics by studying the intestinal microbiota.

  18. Studies on corrosion inhibitors for the cooling water system at the Heavy Water Project, Kota

    International Nuclear Information System (INIS)

    Pillai, B.P.; Mehta, C.T.; Abubacker, K.M.

    1986-01-01

    The Heavy Water Project at Kota uses the water from the Rana Pratap Sagar Lake as coolant in the open recirculation system. In order to find suitable corrosion inhibitors for the above system, a series of laboratory experiments on corrosion inhibitors were carried out using the constructional materials of the cooling water system and a number of proprietary formulations and the results are tabulated. From the data thus generated through various laboratory experiments, the most useful ones have been recommended for application in practice. (author)

  19. Cooling system upon reactor isolation

    International Nuclear Information System (INIS)

    Yamamoto, Kohei; Oda, Shingo; Miura, Satoshi

    1992-01-01

    A water level indicator for detecting the upper limit value for a range of using a suppression pool and a thermometer for detecting the temperature of water at the cooling water inlet of an auxiliary device are disposed. When a detection signal is intaken and the water level in the suppression pool reach the upper limit value for the range of use, a secondary flow rate control value is opened and a primary flow rate control valve is closed. When the temperature of the water at the cooling water inlet of the auxiliary device reaches the upper limit value, the primary and the secondary flow rate control valves are opened. During a stand-by state, the first flow rate control valve is set open and the secondary flow rate control valve is set closed respectively. After reactor isolation, if a reactor water low level signal is received, an RCIC pump is actuated and cooling water is sent automatically under pressure from a condensate storage tank to the reactor and the auxiliary device requiring coolants by way of the primary flow rate control valve. Rated flow rate is ensured in the reactor and cooling water of an appropriate temperature can be supplied to the auxiliary device. (N.H.)

  20. Study on the combustion characteristics of a premixed combustion system with exhaust gas recirculation

    International Nuclear Information System (INIS)

    Yu, Byeonghun; Kum, Sung-Min; Lee, Chang-Eon; Lee, Seungro

    2013-01-01

    The boiler of a premixed combustion system with EGR (exhaust gas recirculation) is investigated to explore the potential for increasing thermal efficiency and lowering pollutant emissions. To achieve this purpose, a thermodynamic analysis is performed to predict the effect of EGR on the thermodynamic efficiency for various equivalence ratios. Experiments of a preheated air condensing boiler with EGR were conducted to measure the changes in the thermal efficiency and the characteristics of the pollutant emission. Finally, a 1-D premixed code was calculated to understand the effect of the EGR method on the NO reduction mechanism. The results of the thermodynamic analysis show that the thermodynamic efficiency is not changed because the temperature and the amount of the exhaust gas are unchanged, even though the EGR method is implemented in the system. However, when the EGR method is used with an equivalence ratio near 1.00, it is experimentally verified that the thermal efficiency increases and the NO x concentration decreases. Based on the results from numerical calculations, it is shown that the NO production rates of N + O 2 ↔ NO + O and N + OH ↔ NO + H are remarkably changed due to the decrease in the flame temperature and the NO mole fraction is decreased. - Highlights: • Premixed combustion system with EGR is studied for a high efficiency and low NO x . • All research is performed with various EGR and equivalence ratios. • It verified that efficiency increases and the NO x emission decreases with EGR method. • NO production rates are remarkably changed by N + O 2 ↔ NO + O and N + OH ↔ NO + H with EGR

  1. Investigation of some green compounds as corrosion and scale inhibitors for cooling systems

    Energy Technology Data Exchange (ETDEWEB)

    Quraishi, M.A.; Farooqi, I.H.; Saini, P.A. (Aligarh Muslim Univ. (India))

    1999-05-01

    The performance of an open-recirculating cooling system, an important component in most industries, is affected by corrosion and scale formation. Numerous additives have been used in the past for the control of corrosion and scale formation. Effects of the naturally occurring compounds azadirachta indica (leaves), punica granatum (shell), and momordica charantia (fruits), on corrosion of mild steel in 3% sodium chloride (NaCl) were assessed using weight loss, electrochemical polarization, and impedance techniques. Extracts of the compounds exhibited excellent inhibition efficiencies comparable to that of hydroxyethylidine diphosphonic acid (HEDP), the most preferred cooling water inhibitor. The compounds were found effective under static and flowing conditions. Extracts were quite effective in retarding formation of scales, and the maximum antiscaling efficiency was exhibited by the extract of azadirachta indica (98%). The blowdown of the cooling system possessed color and chemical oxygen demand (COD). Concentrations of these parameters were reduced by an adsorption process using activated carbon as an adsorbent.

  2. Elastocaloric cooling materials and systems

    Science.gov (United States)

    Takeuchi, Ichiro

    2015-03-01

    We are actively pursuing applications of thermoelastic (elastocaloric) cooling using shape memory alloys. Latent heat associated with martensitic transformation of shape memory alloys can be used to run cooling cycles with stress-inducing mechanical drives. The coefficient of performance of thermoelastic cooling materials can be as high as 11 with the directly measured DT of around 17 °C. Depending on the stress application mode, the number of cycles to fatigue can be as large as of the order of 105. Efforts to design and develop thermoelastic alloys with long fatigue life will be discussed. The current project at the University of Maryland is focused on development of building air-conditioners, and at Maryland Energy and Sensor Technologies, smaller scale commercial applications are being pursued. This work is carried out in collaboration with Jun Cui, Yiming Wu, Suxin Qian, Yunho Hwang, Jan Muehlbauer, and Reinhard Radermacher, and it is funded by the ARPA-E BEETIT program and the State of Maryland.

  3. Removal of nitrogen by Algal Turf Scrubber Technology in recirculating aquaculture system

    NARCIS (Netherlands)

    Valeta, J.; Verdegem, M.C.J.

    2015-01-01

    Ongoing research in recirculation aquaculture focuses on evaluating and improving the purification potential of different types of filters. Algal Turf Scrubber (ATS) are special as they combine sedimentation and biofiltration. An ATS was subjected to high nutrient loads of catfish effluent to

  4. Closed recirculation-Water treatment

    International Nuclear Information System (INIS)

    Hamza, Hamza B.; Ben Ali, Salah; Saad, Mohamed A.; Traish, Massud R.

    2005-01-01

    This water treatment is a practical work applied in the center, for a closed recirculation-water system. The system had experienced a serious corrosion problem, due to the use of inadequate water. This work includes chemical preparation for the system. Water treatment, special additives, and follow-up, which resulted in the stability of the case. This work can be applied specially for closed recirculation warm, normal, and chilled water. (author)

  5. Cooling Grapple System for FMEF hot cell

    International Nuclear Information System (INIS)

    Semmens, L.S.; Frandsen, G.B.; Tome, R.

    1983-01-01

    A Cooling Grapple System was designed and built to handle fuel assemblies within the FMEF hot cell. The variety of functions for which it is designed makes it unique from grapples presently in use. The Cooling Grapple can positively grip and transport assemblies vertically, retrieve assemblies from molten sodium where six inches of grapple tip is submerged, cool 7 kw assemblies in argon, and service an in-cell area of 372 m 2 (4000 ft 2 ). Novel and improved operating and maintenance features were incorporated in the design including a shear pin and mechanical catcher system to prevent overloading the grapple while allowing additional reaction time for crane shutdown

  6. The ATLAS IBL CO2 Cooling System

    CERN Document Server

    Verlaat, Bartholomeus; The ATLAS collaboration

    2016-01-01

    The Atlas Pixel detector has been equipped with an extra B-layer in the space obtained by a reduced beam pipe. This new pixel detector called the ATLAS Insertable B-Layer (IBL) is installed in 2014 and is operational in the current ATLAS data taking. The IBL detector is cooled with evaporative CO2 and is the first of its kind in ATLAS. The ATLAS IBL CO2 cooling system is designed for lower temperature operation (<-35⁰C) than the previous developed CO2 cooling systems in High Energy Physics experiments. The cold temperatures are required to protect the pixel sensors for the high expected radiation dose up to 550 fb^-1 integrated luminosity. This paper describes the design, development, construction and commissioning of the IBL CO2 cooling system. It describes the challenges overcome and the important lessons learned for the development of future systems which are now under design for the Phase-II upgrade detectors.

  7. Numerical simulation of the hydrodynamics within octagonal tanks in recirculating aquaculture systems

    Science.gov (United States)

    Liu, Yao; Liu, Baoliang; Lei, Jilin; Guan, Changtao; Huang, Bin

    2017-07-01

    A three-dimensional numerical model was established to simulate the hydrodynamics within an octagonal tank of a recirculating aquaculture system. The realizable k- ɛ turbulence model was applied to describe the flow, the discrete phase model (DPM) was applied to generate particle trajectories, and the governing equations are solved using the finite volume method. To validate this model, the numerical results were compared with data obtained from a full-scale physical model. The results show that: (1) the realizable k- ɛ model applied for turbulence modeling describes well the flow pattern in octagonal tanks, giving an average relative error of velocities between simulated and measured values of 18% from contour maps of velocity magnitudes; (2) the DPM was applied to obtain particle trajectories and to simulate the rate of particle removal from the tank. The average relative error of the removal rates between simulated and measured values was 11%. The DPM can be used to assess the self-cleaning capability of an octagonal tank; (3) a comprehensive account of the hydrodynamics within an octagonal tank can be assessed from simulations. The velocity distribution was uniform with an average velocity of 15 cm/s; the velocity reached 0.8 m/s near the inlet pipe, which can result in energy losses and cause wall abrasion; the velocity in tank corners was more than 15 cm/s, which suggests good water mixing, and there was no particle sedimentation. The percentage of particle removal for octagonal tanks was 90% with the exception of a little accumulation of ≤ 5 mm particle in the area between the inlet pipe and the wall. This study demonstrated a consistent numerical model of the hydrodynamics within octagonal tanks that can be further used in their design and optimization as well as promote the wide use of computational fluid dynamics in aquaculture engineering.

  8. Dry cooling systems with plastic surfaces

    International Nuclear Information System (INIS)

    Roma, Carlo; Leonelli, Vincenzo

    1975-01-01

    Research and experiments made on dry cooling systems with plastic surfaces are described. The demonstration program planned in Italy for a 100Gcal/h dry cooling system is exposed, and an installation intended for a large 1300Mwe nuclear power station is described with reference to the assembly (exploitation and maintenance included). The performance and economic data relating to this installation are also exposed [fr

  9. Core test reactor shield cooling system analysis

    International Nuclear Information System (INIS)

    Larson, E.M.; Elliott, R.D.

    1971-01-01

    System requirements for cooling the shield within the vacuum vessel for the core test reactor are analyzed. The total heat to be removed by the coolant system is less than 22,700 Btu/hr, with an additional 4600 Btu/hr to be removed by the 2-inch thick steel plate below the shield. The maximum temperature of the concrete in the shield can be kept below 200 0 F if the shield plug walls are kept below 160 0 F. The walls of the two ''donut'' shaped shield segments, which are cooled by the water from the shield and vessel cooling system, should operate below 95 0 F. The walls of the center plug, which are cooled with nitrogen, should operate below 100 0 F. (U.S.)

  10. Understanding aging in containment cooling systems

    International Nuclear Information System (INIS)

    Lofaro, R.J.

    1993-01-01

    A study has been performed to assess the effects of aging in nuclear power plant containment cooling systems. Failure records from national databases, as well as plant specific data were reviewed and analyzed to identify aging characteristics for this system. The predominant aging mechanisms were determined, along with the most frequently failed components and their associated failure modes. This paper discusses the aging mechanisms present in the containment spray system and the containment fan cooler system, which are two systems used to provide the containment cooling function. The failure modes, along with the relative frequency of each is also discussed

  11. New Protective Measures for Cooling Systems

    International Nuclear Information System (INIS)

    Carter, D. Anthony; Nonohue, Jonh M.

    1974-01-01

    Cooling water treatments have been updated and improved during the last few years. Particularly important are the nontoxic programs which conform plant cooling water effluents to local water quality standards without expenditures for capital equipment. The relationship between scaling and corrosion in natural waters has been recognized for many years. This relationship is the basis for the Langelier Saturation Index control method which was once widely applied to reduce corrosion in cooling water systems. It used solubility characteristics to maintain a very thin deposit on metal surfaces for preventing corrosion. This technique was rarely successful. That is, the solubility of calcium carbonate and most other inorganic salts depends on temperature. If good control exists on cold surfaces, excessive deposition results on the heat transfer tubes. Also, because water characteristic normally vary in a typical cooling system, precise control of scaling at both hot and cold surfaces is virtually impossible

  12. Cooling system with automated seasonal freeze protection

    Science.gov (United States)

    Campbell, Levi A.; Chu, Richard C.; David, Milnes P.; Ellsworth, Jr., Michael J.; Iyengar, Madhusudan K.; Simons, Robert E.; Singh, Prabjit; Zhang, Jing

    2016-05-24

    An automated multi-fluid cooling system and method are provided for cooling an electronic component(s). The cooling system includes a coolant loop, a coolant tank, multiple valves, and a controller. The coolant loop is at least partially exposed to outdoor ambient air temperature(s) during normal operation, and the coolant tank includes first and second reservoirs containing first and second fluids, respectively. The first fluid freezes at a lower temperature than the second, the second fluid has superior cooling properties compared with the first, and the two fluids are soluble. The multiple valves are controllable to selectively couple the first or second fluid into the coolant in the coolant loop, wherein the coolant includes at least the second fluid. The controller automatically controls the valves to vary first fluid concentration level in the coolant loop based on historical, current, or anticipated outdoor air ambient temperature(s) for a time of year.

  13. Corrosion products, activity transport and deposition in boiling water reactor recirculation systems

    International Nuclear Information System (INIS)

    Alder, H.P.; Buckley, D.; Grauer, R.; Wiedemann, K.H.

    1992-01-01

    The deposition of activated corrosion products in the recirculation loops of Boiling Water Reactors produces increased radiation levels which lead to a corresponding increase in personnel radiation dose during shut down and maintenance. The major part of this dose rate is due to cobalt-60. Based on a comprehensive literature study concerning this theme, it has been attempted to identify the individual stages of the activity build-up and to classify their importance. The following areas are discussed in detail: The origins of the corrosion products and of cobalt-59 in the reactor feedwaters; the consolidation of the cobalt in the fuel pins deposits (activation); the release and transport of cobalt-60; the build-up of cobalt-60 in the corrosion products in the recirculation loops. Existing models of the build-up of circuit radioactivity are discussed and the operating experiences from selected reactors are summarized. 90 refs, figs and tabs

  14. Rust Inhibitor And Fungicide For Cooling Systems

    Science.gov (United States)

    Adams, James F.; Greer, D. Clay

    1988-01-01

    Mixture of benzotriazole, benzoic acid, and fungicide prevents growth of rust and fungus. Water-based cooling mixture made from readily available materials prevents formation of metallic oxides and growth of fungi in metallic pipes. Coolant remains clear and does not develop thick sludge tending to collect in low points in cooling systems with many commercial rust inhibitors. Coolant compatible with iron, copper, aluminum, and stainless steel. Cannot be used with cadmium or cadmium-plated pipes.

  15. Florfenicol residues in Rainbow Trout after oral dosing in recirculating and flow-through culture systems

    Science.gov (United States)

    Meinertz, Jeffery R.; Hess, Karina R.; Bernady, Jeffry A.; Gaikowski, M. P.; Whitsel, Melissa; Endris, R. G.

    2014-01-01

    Aquaflor is a feed premix for fish containing the broad spectrum antibacterial agent florfenicol (FFC) incorporated at a ratio of 50% (w/w). To enhance the effectiveness of FFC for salmonids infected with certain isolates of Flavobacterium psychrophilum causing coldwater disease, the FFC dose must be increased from the standard 10 mg·kg−1 body weight (BW)·d−1 for 10 consecutive days. A residue depletion study was conducted to determine whether FFC residues remaining in the fillet tissue after treating fish at an increased dose would be safe for human consumption. Groups of Rainbow Trout Oncorhynchus mykiss (total n = 144; weight range, 126–617 g) were treated with FFC at 20 mg·kg−1 BW·d−1 for 10 d in a flow-through system (FTS) and a recirculating aquaculture system (RAS) each with a water temperature of ∼13°C. The two-tank RAS included a nontreated tank containing 77 fish. Fish were taken from each tank (treated tank, n = 16; nontreated tank, n = 8) at 6, 12, 24, 48, 72, 120, 240, 360, and 480 h posttreatment. Florfenicol amine (FFA) concentrations (the FFC marker residue) in skin-on fillets from treated fish were greatest at 12 h posttreatment (11.58 μg/g) in the RAS and were greatest at 6 h posttreatment (11.09 μg/g) in the FTS. The half-lives for FFA in skin-on fillets from the RAS and FTS were 20.3 and 19.7 h, respectively. Assimilation of FFC residues in the fillets of nontreated fish sharing the RAS with FFC-treated fish was minimal. Florfenicol water concentrations peaked in the RAS-treated tank and nontreated tanks at 10 h (453 μg/L) and 11 h (442 μg/L) posttreatment, respectively. Monitoring of nitrite concentrations throughout the study indicated the nitrogen oxidation efficiency of the RAS biofilter was minimally impacted by the FFC treatment.

  16. Performance investigation of solid desiccant evaporative cooling system configurations in different climatic zones

    International Nuclear Information System (INIS)

    Ali, Muzaffar; Vukovic, Vladimir; Sheikh, Nadeem Ahmed; Ali, Hafiz M.

    2015-01-01

    Highlights: • Five configurations of a DEC system are analyzed in five climate zones. • DEC system model configurations are developed in Dymola/Modelica. • Performance analysis predicted a suitable DEC system configuration for each climate zone. • Results show that climate of Vienna, Sao Paulo, and Adelaide favors the ventilated-dunkle cycle. • While ventilation cycle configuration suits the climate of Karachi and Shanghai. - Abstract: Performance of desiccant evaporative cooling (DEC) system configurations is strongly influenced by the climate conditions and varies widely in different climate zones. Finding the optimal configuration of DEC systems for a specific climatic zone is tedious and time consuming. This investigation conducts performance analysis of five DEC system configurations under climatic conditions of five cities from different zones: Vienna, Karachi, Sao Paulo, Shanghai, and Adelaide. On the basis of operating cycle, three standard and two modified system configurations (ventilation, recirculation, dunkle cycles; ventilated-recirculation and ventilated-dunkle cycles) are analyzed in these five climate zones. Using an advance equation-based object-oriented (EOO) modeling and simulation approach, optimal configurations of a DEC system are determined for each climate zone. Based on the hourly climate data of each zone for its respective design cooling day, performance of each system configuration is estimated using three performance parameters: cooling capacity, COP, and cooling energy delivered. The results revealed that the continental/micro-thermal climate of Vienna, temperate/mesothermal climate of Sao Paulo, and dry-summer subtropical climate of Adelaide favor the use of ventilated-dunkle cycle configuration with average COP of 0.405, 0.89 and 1.01 respectively. While ventilation cycle based DEC configuration suits arid and semiarid climate of Karachi and another category of temperate/mesothermal climate of Shanghai with average COP of

  17. Controlled cooling of an electronic system for reduced energy consumption

    Science.gov (United States)

    David, Milnes P.; Iyengar, Madhusudan K.; Schmidt, Roger R.

    2016-08-09

    Energy efficient control of a cooling system cooling an electronic system is provided. The control includes automatically determining at least one adjusted control setting for at least one adjustable cooling component of a cooling system cooling the electronic system. The automatically determining is based, at least in part, on power being consumed by the cooling system and temperature of a heat sink to which heat extracted by the cooling system is rejected. The automatically determining operates to reduce power consumption of the cooling system and/or the electronic system while ensuring that at least one targeted temperature associated with the cooling system or the electronic system is within a desired range. The automatically determining may be based, at least in part, on one or more experimentally obtained models relating the targeted temperature and power consumption of the one or more adjustable cooling components of the cooling system.

  18. Controlled cooling of an electronic system for reduced energy consumption

    Energy Technology Data Exchange (ETDEWEB)

    David, Milnes P.; Iyengar, Madhusudan K.; Schmidt, Roger R.

    2018-01-30

    Energy efficient control of a cooling system cooling an electronic system is provided. The control includes automatically determining at least one adjusted control setting for at least one adjustable cooling component of a cooling system cooling the electronic system. The automatically determining is based, at least in part, on power being consumed by the cooling system and temperature of a heat sink to which heat extracted by the cooling system is rejected. The automatically determining operates to reduce power consumption of the cooling system and/or the electronic system while ensuring that at least one targeted temperature associated with the cooling system or the electronic system is within a desired range. The automatically determining may be based, at least in part, on one or more experimentally obtained models relating the targeted temperature and power consumption of the one or more adjustable cooling components of the cooling system.

  19. Effect of stocking density on performances of juvenile turbot ( Scophthalmus maximus) in recirculating aquaculture systems

    Science.gov (United States)

    Li, Xian; Liu, Ying; Blancheton, Jean-Paul

    2013-05-01

    Limited information has been available about the influence of loading density on the performances of Scophthalmus maximus, especially in recirculating aquaculture systems (RAS). In this study, turbot (13.84±2.74 g; average weight±SD) were reared at four different initial densities (low 0.66, medium 1.26, sub-high 2.56, high 4.00 kg/m2) for 10 weeks in RAS at 23±1°C. Final densities were 4.67, 7.25, 14.16, and 17.47 kg/m2, respectively, which translate to 82, 108, 214, and 282 percent coverage of the tank bottom. Density had both negative and independent impacts on growth. The final mean weight, specific growth rate (SGR), and voluntary feed intake significantly decreased and the coefficient of variation (CV) of final body weight increased with increase in stocking density. The medium and sub-high density groups did not differ significantly in SGR, mean weight, CV, food conversion rate (FCR), feed intake, blood parameters, and digestive enzymes. The protease activities of the digestive tract at pH 7, 8.5, 9, and 10 were significantly higher for the highest density group, but tended to be lower (not significantly) at pH 4 and 8.5 for the lowest density group. The intensity of protease activity was inversely related to feed intake at the different densities. Catalase activity was higher (but not significantly) at the highest density, perhaps because high density started to induce an oxidative effect in turbot. In conclusion, turbot can be cultured in RAS at a density of less than 17.47 kg/m2. With good water quality and no feed limitation, initial density between 1.26 and 2.56 kg/m2 (final: 7.25 and 14.16 kg/m2) would not negatively affect the turbot cultured in RAS. For culture at higher density, multi-level feeding devices are suggested to ease feeding competition.

  20. Stability of therapeutic albumin solutions used for molecular adsorbent recirculating system-based liver dialysis.

    Science.gov (United States)

    De Bruyn, Tom; Meijers, Björn; Evenepoel, Pieter; Laub, Ruth; Willems, Ludo; Augustijns, Patrick; Annaert, Pieter

    2012-01-01

    Mounting evidence suggests beneficial effects of albumin dialysis-based liver support in patients suffering from acute-on-chronic liver failure. Molecular adsorbent recirculating system (MARS) is a nonbiological liver support device, based on the exchange of albumin-bound toxins between the patient's blood and a 20% human serum albumin solution in a secondary circuit. Bound toxins are continuously removed from the circulating albumin by exposure to activated charcoal and an ion-exchange resin. The aim of the present in vitro study was to determine the impact of exposure to charcoal and resin on the ligand binding properties of albumins, containing various levels of stabilizers and obtained from different suppliers (Baxter, CAF-DCF [Red Cross], and Sigma-Aldrich). Albumin binding properties were assessed by measuring equilibrium binding properties of warfarin, diazepam, and salicylate before and after incubation (for up to 7 h) with adsorbing materials; albumin-associated esterase-like activities were also determined. Notable changes in albumin binding upon incubation with adsorbing materials were only observed when using warfarin as a ligand. Affinity of warfarin for the Baxter and Sigma albumins showed a pronounced decrease (higher K(d) ) after the 1-7-h exposure to charcoal or resin. In the absence of adsorbing materials, similar effects were found, indicating that incubation time per se affects albumin binding properties. Following exposure to resin, Baxter albumin binding capacity (B(max)) increased about twofold. For albumin obtained from CAF-DCF, binding affinity and capacity for warfarin were constant under all conditions tested. Esterase-like activities associated with these albumins were either maintained or enhanced (up to 2.5-fold in case of Sigma albumin) following 7-h incubations with adsorbing materials. Our data suggest limited direct influence of the presence of stabilizers in therapeutic albumin solutions on baseline binding properties of human

  1. System for Cooling of Electronic Components

    Science.gov (United States)

    Vasil'ev, L. L.; Grakovich, L. P.; Dragun, L. A.; Zhuravlev, A. S.; Olekhnovich, V. A.; Rabetskii, M. I.

    2017-01-01

    Results of computational and experimental investigations of heat pipes having a predetermined thermal resistance and a system based on these pipes for air cooling of electronic components and diode assemblies of lasers are presented. An efficient compact cooling system comprising heat pipes with an evaporator having a capillary coating of a caked copper powder and a condenser having a developed outer finning, has been deviced. This system makes it possible to remove, to the ambient air, a heat flow of power more than 300 W at a temperature of 40-50°C.

  2. MULTIFUNCTIONAL SOLAR SYSTEMS FOR HEATING AND COOLING

    Directory of Open Access Journals (Sweden)

    Doroshenko A.V.

    2010-12-01

    Full Text Available The basic circuits of multifunctional solar systems of air drainage, heating (hot water supply and heating, cooling and air conditioning are developed on the basis of open absorption cycle with a direct absorbent regeneration. Basic decisions for new generation of gas-liquid solar collectors are developed. Heat-mass-transfer apparatus included in evaporative cooling system, are based on film interaction of flows of gas and liquid and in them, for the creation of nozzle, multi-channel structures from polymeric materials and porous ceramics are used. Preliminary analysis of multifunctional systems possibilities is implemented.

  3. Spacesuit Water Membrane Evaporator; An Enhanced Evaporative Cooling Systems for the Advanced Extravehicular Mobility Unit Portable Life Support System

    Science.gov (United States)

    Bue, Grant C.; Makinen, Janice V.; Miller, Sean.; Campbell, Colin; Lynch, Bill; Vogel, Matt; Craft, Jesse; Petty, Brian

    2014-01-01

    Spacesuit Water Membrane Evaporator - Baseline heat rejection technology for the Portable Life Support System of the Advanced EMU center dot Replaces sublimator in the current EMU center dot Contamination insensitive center dot Can work with Lithium Chloride Absorber Radiator in Spacesuit Evaporator Absorber Radiator (SEAR) to reject heat and reuse evaporated water The Spacesuit Water Membrane Evaporator (SWME) is being developed to replace the sublimator for future generation spacesuits. Water in LCVG absorbs body heat while circulating center dot Warm water pumped through SWME center dot SWME evaporates water vapor, while maintaining liquid water - Cools water center dot Cooled water is then recirculated through LCVG. center dot LCVG water lost due to evaporation (cooling) is replaced from feedwater The Independent TCV Manifold reduces design complexity and manufacturing difficulty of the SWME End Cap. center dot The offset motor for the new BPV reduces the volume profile of the SWME by laying the motor flat on the End Cap alongside the TCV.

  4. System and method for regeneration and recirculation of a reducing agent using highly exothermic reactions induced by mixed industrial slags

    Science.gov (United States)

    Nakano, Jinichiro; Bennett, James P.; Nakano, Anna

    2017-12-12

    Embodiments relate to systems and methods for regenerating and recirculating a CO, H.sub.2 or combinations thereof utilized for metal oxide reduction in a reduction furnace. The reduction furnace receives the reducing agent, reduces the metal oxide, and generates an exhaust of the oxidized product. The oxidized product is transferred to a mixing vessel, where the oxidized product, a calcium oxide, and a vanadium oxide interact to regenerate the reducing agent from the oxidized product. The regenerated reducing agent is transferred back to the reduction furnace for continued metal oxide reductions.

  5. Slab cooling system design using computer simulation

    NARCIS (Netherlands)

    Lain, M.; Zmrhal, V.; Drkal, F.; Hensen, J.L.M.

    2007-01-01

    For a new technical library building in Prague computer simulations were carried out to help design of slab cooling system and optimize capacity of chillers. In the paper is presented concept of new technical library HVAC system, the model of the building, results of the energy simulations for

  6. Radiant Heating and Cooling Systems. Part two

    DEFF Research Database (Denmark)

    Kim, Kwan Woo; Olesen, Bjarne W.

    2015-01-01

    Control of the heating and cooling system needs to be able to maintain the indoor temperatures within the comfort range under the varying internal loads and external climates. To maintain a stable thermal environment, the control system needs to maintain the balance between the heat gain...

  7. Molecular Adsorbent Recirculating System Can Reduce Short-Term Mortality Among Patients With Acute-on-Chronic Liver Failure-A Retrospective Analysis.

    Science.gov (United States)

    Gerth, Hans U; Pohlen, Michele; Thölking, Gerold; Pavenstädt, Hermann; Brand, Marcus; Hüsing-Kabar, Anna; Wilms, Christian; Maschmeier, Miriam; Kabar, Iyad; Torner, Josep; Pavesi, Marco; Arroyo, Vicente; Banares, Rafael; Schmidt, Hartmut H J

    2017-10-01

    Acute-on-chronic liver failure is associated with numerous consecutive organ failures and a high short-term mortality rate. Molecular adsorbent recirculating system therapy has demonstrated beneficial effects on the distinct symptoms, but the associated mortality data remain controversial. Retrospective analysis of acute-on-chronic liver failure patients receiving either standard medical treatment or standard medical treatment and molecular adsorbent recirculating system. Secondary analysis of data from the prospective randomized Recompensation of Exacerbated Liver Insufficiency with Hyperbilirubinemia and/or Encephalopathy and/or Renal Failure trial by applying the recently introduced Chronic Liver Failure-criteria. Medical Departments of University Hospital Muenster (Germany). This analysis was conducted in two parts. First, 101 patients with acute-on-chronic liver failure grades 1-3 and Chronic Liver Failure-C-Organ Failure liver subscore equals to 3 but stable pulmonary function were identified and received either standard medical treatment (standard medical treatment, n = 54) or standard medical treatment and molecular adsorbent recirculating system (n = 47) at the University Hospital Muenster. Second, the results of this retrospective analysis were tested against the Recompensation of Exacerbated Liver Insufficiency with Hyperbilirubinemia and/or Encephalopathy and/or Renal Failure trial. Standard medical treatment and molecular adsorbent recirculating system. Additionally to improved laboratory variables (bilirubin and creatinine), the short-term mortality (up to day 14) of the molecular adsorbent recirculating system group was significantly reduced compared with standard medical treatment. A reduced 14-day mortality rate was observed in the molecular adsorbent recirculating system group (9.5% vs 50.0% with standard medical treatment; p = 0.004), especially in patients with multiple organ failure (acute-on-chronic liver failure grade 2-3). Concerning the

  8. Smart Cooling Controlled System Exploiting Photovoltaic Renewable Energy Systems

    Directory of Open Access Journals (Sweden)

    Ahmad Atieh

    2018-03-01

    Full Text Available A smart cooling system to control the ambient temperature of a premise in Amman, Jordan, is investigated and implemented. The premise holds 650 people and has 14 air conditioners with the cooling capacity ranging from 3 to 5 ton refrigerant (TR each. The control of the cooling system includes implementing different electronics circuits that are used to sense the ambient temperature and humidity, count the number of people in the premise and then turn ON/OFF certain air conditioner(s. The data collected by different electronic circuits are fed wirelessly to a microcontroller, which decides which air conditioner will be turned ON/OFF, its location and its desired set cooling temperature. The cooling system is integrated with an on-grid solar photovoltaic energy system to minimize the operational cost of the overall cooling system.

  9. Passive cooling systems in power reactors

    International Nuclear Information System (INIS)

    Aharon, J.; Harrari, R.; Weiss, Y.; Barnea, Y.; Katz, M.; Szanto, M.

    1996-01-01

    This paper reviews several R and D activities associated with the subject of passive cooling systems, conducted by the N.R.C.Negev thermohydraulic group. A short introduction considering different types of thermosyphons and their applications is followed by a detailed description of the experimental work, its results and conclusions. An ongoing research project is focused on the evaluation of the external dry air passive containment cooling system (PCCS) in the AP-600 (Westinghouse advanced pressurized water reactor). In this context some preliminary theoretical results and planned experimental research are for the fature described

  10. Power plant cooling systems: trends and challenges

    International Nuclear Information System (INIS)

    Rittenhouse, R.C.

    1979-01-01

    A novel design for an intake and discharge system at the Belle River plant is described followed by a general discussion of water intake screens and porous dikes for screening fish and zooplankton. The intake system for the San Onofre PWR plant is described and the state regulations controlling the use of water for power plants is discussed. The use of sewage effluent as a source of cooling water is mentioned with reference to the Palo Verde plant. Progress in dry cooling and a new wet/dry tower due to be installed at the San Juan plant towards the end of this year, complete the survey

  11. Stochastic cooling system in COSY

    International Nuclear Information System (INIS)

    Brittner, P.; Hacker, H.U.; Prasuhn, D.; Schug, G.; Singer, H.; Spiess, W.; Stassen, R.

    1994-01-01

    The stochastic cooler system in COSY is designed for proton kinetic energies between 0.8 and 2.5 GeV. Fabrication of the mechanical parts of the system is going on. Test results of the prototype measurements as well as data of the active RF-compontens are presented. (orig.)

  12. Stochastic cooling system in COSY

    Energy Technology Data Exchange (ETDEWEB)

    Brittner, P [Forschungszentrum Juelich GmbH (Germany); Hacker, H U [Forschungszentrum Juelich GmbH (Germany); Prasuhn, D [Forschungszentrum Juelich GmbH (Germany); Schug, G [Forschungszentrum Juelich GmbH (Germany); Singer, H [Forschungszentrum Juelich GmbH (Germany); Spiess, W [Forschungszentrum Juelich GmbH (Germany); Stassen, R [Forschungszentrum Juelich GmbH (Germany)

    1994-09-01

    The stochastic cooler system in COSY is designed for proton kinetic energies between 0.8 and 2.5 GeV. Fabrication of the mechanical parts of the system is going on. Test results of the prototype measurements as well as data of the active RF-compontens are presented. (orig.)

  13. Micro- and Nanostructural Characteristics of Particles Before and After an Exhaust Gas Recirculation System Scrubber

    DEFF Research Database (Denmark)

    Lieke, Kirsten Inga; Rosenørn, Thomas; Pedersen, Jannik

    2013-01-01

    microscopy (TEM) grids on two stages. Micro- and nanostructural characteristics of sin-gle particles were studied by TEM. Image analysis was carried out on overview and high-resolution images, revealing influence of the exhaust gas treatment (scrubber) on the particle morphology and mixing state. Soot......This work provides insight into the morphology and mixing state of submicron particles in diesel exhaust from a ship engine with an exhaust gas recirculation scrubber. Particles from this low-speed ship engine on test bed were collected using a microiner-tial impactor with transmission electron...

  14. Char-recirculation biomass gasification system--a site-specific feasibility study

    International Nuclear Information System (INIS)

    Purdy, K.R.; Kerr, C.P.; Hensley, B.D.

    1991-01-01

    A site-specific feasibility study was conducted for a char-recirculation biomass gasification plant which would dispose of the chippable solid residues of the area sawmills. The plant would receive green hardwood chips and convert them into active charcoal while producing process steam and electrical power. An economic analysis was performed on the basis of not-for-profit operation, marketing crushed active charcoal to a broker at a discounted price, and displacing purchased electric power. Given a market for the active charcoal, the plant was judged to be economically viable

  15. Reduced Volume Prototype Spacesuit Water Membrane Evaporator; A Next-Generation Evaporative Cooling System for the Advanced Extravehicular Mobility Unit Portable Life Support System

    Science.gov (United States)

    Makinen, Janice V.; Anchondo, Ian; Bue, Grant C.; Campbell, Colin; Colunga, Aaron

    2013-01-01

    Development of the Advanced Extravehicular Mobility Unit (AEMU) portable life support subsystem (PLSS) is currently under way at NASA Johnson Space Center. The AEMU PLSS features a new evaporative cooling system, the reduced volume prototype (RVP) spacesuit water membrane evaporator (SWME). The RVP SWME is the third generation of hollow fiber SWME hardware. Like its predecessors, RVP SWME provides nominal crew member and electronics cooling by flowing water through porous hollow fibers. Water vapor escapes through the hollow fiber pores, thereby cooling the liquid water that remains inside of the fibers. This cooled water is then recirculated to remove heat from the crew member and PLSS electronics. Major design improvements, including a 36% reduction in volume, reduced weight, and a more flight-like backpressure valve, facilitate the packaging of RVP SWME in the AEMU PLSS envelope. The development of these evaporative cooling systems will contribute to a more robust and comprehensive AEMU PLSS.

  16. Atmospheric impacts of evaporative cooling systems

    International Nuclear Information System (INIS)

    Carson, J.E.

    1976-10-01

    The report summarizes available information on the effects of various power plant cooling systems on the atmosphere. While evaporative cooling systems sharply reduce the biological impacts of thermal discharges in water bodies, they create (at least, for heat-release rates comparable to those of two-unit nuclear generating stations) atmospheric changes. For an isolated site such as required for a nuclear power plant, these changes are rather small and local, and usually environmentally acceptable. However, one cannot say with certainty that these effects will remain small as the number of reactors on a given site increases. There must exist a critical heat load for a specific site which, if exceeded, can create its own weather patterns, and thus create inadvertent weather changes such as rain and snow, severe thunderstorms, and tornadoes. Because proven mathematical models are not available, it is not now possible to forecast precisely the extent and frequency of the atmospheric effects of a particular heat-dissipation system at a particular site. Field research on many aspects of cooling system operation is needed in order to document and quantify the actual atmospheric changes caused by a given cooling system and to provide the data needed to develop and verify mathematical and physical models. The more important topics requiring field study are plume rise, fogging and icing (from certain systems), drift emission and deposition rates, chemical interactions, cloud and precipitation formation and critical heat-release rates

  17. The ATLAS IBL CO2 Cooling System

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00237783; The ATLAS collaboration; Zwalinski, L.; Bortolin, C.; Vogt, S.; Godlewski, J.; Crespo-Lopez, O.; Van Overbeek, M.; Blaszcyk, T.

    2017-01-01

    The ATLAS Pixel detector has been equipped with an extra B-layer in the space obtained by a reduced beam pipe. This new pixel detector called the ATLAS Insertable B-Layer (IBL) is installed in 2014 and is operational in the current ATLAS data taking. The IBL detector is cooled with evaporative CO2 and is the first of its kind in ATLAS. The ATLAS IBL CO2 cooling system is designed for lower temperature operation (<-35⁰C) than the previous developed CO2 cooling systems in High Energy Physics experiments. The cold temperatures are required to protect the pixel sensors for the high expected radiation dose up to 550 fb^-1 integrated luminosity.

  18. Disinfection of bacterial biofilms in pilot-scale cooling tower systems.

    Science.gov (United States)

    Liu, Yang; Zhang, Wei; Sileika, Tadas; Warta, Richard; Cianciotto, Nicholas P; Packman, Aaron I

    2011-04-01

    The impact of continuous chlorination and periodic glutaraldehyde treatment on planktonic and biofilm microbial communities was evaluated in pilot-scale cooling towers operated continuously for 3 months. The system was operated at a flow rate of 10,080 l day(-1). Experiments were performed with a well-defined microbial consortium containing three heterotrophic bacteria: Pseudomonas aeruginosa, Klebsiella pneumoniae and Flavobacterium sp. The persistence of each species was monitored in the recirculating cooling water loop and in biofilms on steel and PVC coupons in the cooling tower basin. The observed bacterial colonization in cooling towers did not follow trends in growth rates observed under batch conditions and, instead, reflected differences in the ability of each organism to remain attached and form biofilms under the high-through flow conditions in cooling towers. Flavobacterium was the dominant organism in the community, while P. aeruginosa and K. pneumoniae did not attach well to either PVC or steel coupons in cooling towers and were not able to persist in biofilms. As a result, the much greater ability of Flavobacterium to adhere to surfaces protected it from disinfection, whereas P. aeruginosa and K. pneumoniae were subject to rapid disinfection in the planktonic state.

  19. RESEARCHES REGARDING THE TECHNOLOGICAL PERFORMANCES OF CARP REARING DURING WINTER PERIOD IN THE CONDITIONS OF A RECIRCULATING AQUACULTURE SYSTEM

    Directory of Open Access Journals (Sweden)

    G. STEFAN

    2008-10-01

    Full Text Available The techniques of carp culture are highly diversified, ranging from the extensive production in pond or open water with no fertilization or supplemental feeding to highly intensive systems in concrete tanks or cages. Among the different carp species, common carp is the best species reared in intensive monoculture, the others (Chinese and Indian carps being usually cultivated in polyculture (P. Kestemont, 1995. An experiment was conducted in inside recirculation system conditions to identify the technological performances on carp growth and survival at the Fishing and Aquaculture Department, Galati, during winter period (February, 2007 – March, 2007. The 1-year-old carp (Cyprinus carpio 4792g; 4594 g; 4561 g and 4525 g (total weight grew to 7384g; 7017g; 6924g and 7125 g in 44 days in aquarium 1, 2, 3 and 4, respectively. In all aquariums, the fish appeared healthy and no mortality was observed. Feed conversion efficiencies (FCE had similar values among all aquariums, the highest FCE being found in B4 aquarium with 1, 57 value. Water quality parameters were acceptable range for fish culture. Results show that the carp rearing during winter period in the inside recirculation system is a very good economic solution.

  20. Operational cost minimization in cooling water systems

    Directory of Open Access Journals (Sweden)

    Castro M.M.

    2000-01-01

    Full Text Available In this work, an optimization model that considers thermal and hydraulic interactions is developed for a cooling water system. It is a closed loop consisting of a cooling tower unit, circulation pump, blower and heat exchanger-pipe network. Aside from process disturbances, climatic fluctuations are considered. Model constraints include relations concerning tower performance, air flowrate requirement, make-up flowrate, circulating pump performance, heat load in each cooler, pressure drop constraints and climatic conditions. The objective function is operating cost minimization. Optimization variables are air flowrate, forced water withdrawal upstream the tower, and valve adjustment in each branch. It is found that the most significant operating cost is related to electricity. However, for cooled water temperatures lower than a specific target, there must be a forced withdrawal of circulating water and further makeup to enhance the cooling tower capacity. Additionally, the system is optimized along the months. The results corroborate the fact that the most important variable on cooling tower performance is not the air temperature itself, but its humidity.

  1. The Addition of Simple Biological Filters of Different Capacity to Semi‑Recirculating Fish Rearing System and Its Effects

    Directory of Open Access Journals (Sweden)

    Štěpán Lang

    2017-01-01

    Full Text Available Aquaculture is currently one of the fastest growing food-producing sectors, accounting for around 50 % of the world’s food fish production. Limited resources, together with climatic change, have stimulated the search for solutions to support and sustain the production of fish as a source of protein for human consumption. The integration of a biological filtration (BF into a semi-recirculating fish rearing system can increase its carrying capacity and increase system efficiency compared to its’ energy consumption with minimum changes of system composition and minimal costs. Question is the capacity of the BF installed to a system and how it affects water quality. Two different amounts of BF media (surface added to semi-recirculating rearing system compared with the same system without BF were tested in case of this study. The results have shown that if the BF capacity is insufficient, BF can have negative effects to the quality of water environment. The insufficient amount of BF media caused 4 times reduction of ammonia nitrogen (N-NH4+ in system with BF compared to non BF system so it increased the system capacity for feed load 4 times. On the other hand it also increased nitrite nitrogen concentrations permanently more than 5.8 times for BF system compared to non BF system and increased rearing costs because the need of adding chlorides to the system to protect fish from nitrites toxicity. When the BF was dimensioned properly (next year there were almost no N-NH4+ in a system (0.10 mg.l−1 and the concentration of N-NO2− was kept at low levels too (0.150 mg .l−1. The nitrates (N‑NO3− concentration reached the level of 5.37 and 8.65 mg.l−1 in 2012 and 2013 respectively.

  2. Biogas recirculation for simultaneous calcium removal and biogas purification within an expanded granular sludge bed system treating leachate.

    Science.gov (United States)

    Luo, Jinghuan; Lu, Xueqin; Liu, Jianyong; Qian, Guangren; Lu, Yongsheng

    2014-12-01

    Biogas, generated from an expanded granular sludge bed (EGSB) reactor treating municipal solid waste (MSW) leachate, was recirculated for calcium removal from the leachate via a carbonation process with simultaneous biogas purification. Batch trials were performed to optimize the solution pH and imported biogas (CO2) for CaCO3 precipitation. With applicable pH of 10-11 obtained, continuous trials achieved final calcium concentrations of 181-375 mg/L (removal efficiencies≈92.8-96.5%) in the leachate and methane contents of 87.1-91.4% (purification efficiencies≈65.4-82.2%) in the biogas. Calcium-balance study indicates that 23-986 mg Ca/d was released from the bio-system under the carbonized condition where CaCO3 precipitating was moved outside the bioreactor, whereas 7918-9517 mg Ca/d was trapped into the system for the controlled one. These findings demonstrate that carbonation removal of calcium by biogas recirculation could be a promising alternative to pretreat calcium-rich MSW leachate and synergistically to improve methane content. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Decontamination of primary cooling system

    International Nuclear Information System (INIS)

    Morikawa, Yoshitake.

    1985-01-01

    Purpose: To effectively eliminate radioactivity accumulated in pipeways, equipments, etc in primary coolant circuits of BWR type power plants by utilizing ion displacement reactions. Method: The reactor pressure vessel is connected with a feedwater pipeway, steam pipeway and a recycling pipeway. The recycling pipeway is disposed with a recycling pump. A recycling by-pass line is branched from the recycling pipeway and disposed with a recycling system heat exchanger and chemical injection point. Water is filled in the primary coolant and heated 280 0 C. Then, while maintaining water at that temperature, non-radioactive cobalt ions are injected and circulated within the system, by which radioactivity accumulated in pipeways, equipments or the likes can effectively be removed. (Horiuchi, T.)

  4. Method of fabricating a cooled electronic system

    Science.gov (United States)

    Chainer, Timothy J; Gaynes, Michael A; Graybill, David P; Iyengar, Madhusudan K; Kamath, Vinod; Kochuparambil, Bejoy J; Schmidt, Roger R; Schultz, Mark D; Simco, Daniel P; Steinke, Mark E

    2014-02-11

    A method of fabricating a liquid-cooled electronic system is provided which includes an electronic assembly having an electronics card and a socket with a latch at one end. The latch facilitates securing of the card within the socket. The method includes providing a liquid-cooled cold rail at the one end of the socket, and a thermal spreader to couple the electronics card to the cold rail. The thermal spreader includes first and second thermal transfer plates coupled to first and second surfaces on opposite sides of the card, and thermally conductive extensions extending from end edges of the plates, which couple the respective transfer plates to the liquid-cooled cold rail. The extensions are disposed to the sides of the latch, and the card is securable within or removable from the socket using the latch without removing the cold rail or the thermal spreader.

  5. Turbine airfoil with laterally extending snubber having internal cooling system

    Science.gov (United States)

    Scribner, Carmen Andrew; Messmann, Stephen John; Marsh, Jan H.

    2016-09-06

    A turbine airfoil usable in a turbine engine and having at least one snubber with a snubber cooling system positioned therein and in communication with an airfoil cooling system is disclosed. The snubber may extend from the outer housing of the airfoil toward an adjacent turbine airfoil positioned within a row of airfoils. The snubber cooling system may include an inner cooling channel separated from an outer cooling channel by an inner wall. The inner wall may include a plurality of impingement cooling orifices that direct impingement fluid against an outer wall defining the outer cooling channel. In one embodiment, the cooling fluids may be exhausted from the snubber, and in another embodiment, the cooling fluids may be returned to the airfoil cooling system. Flow guides may be positioned in the outer cooling channel, which may reduce cross-flow by the impingement orifices, thereby increasing effectiveness.

  6. Silent cooling system with a double suction type centrifugal fan with backward blades; Ryosuikomi turbo fan wo mochiita teisoon engine reikyaku system no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Funabashi, S. [Hitachi, Ltd., Tokyo (Japan); Nakamura, K. [Hitachi Construction Machinery Co. Ltd., Tokyo (Japan)

    2000-04-25

    We have developed a new cooling system for the engine of construction machinery. This system produces two different air flow routes by a double suction type centrifugal fan with backward blades. We first measured aerodynamic performance and sound level of the double suction type fan, which consists of two single suction type fans of different design, and compared these measurements to those of single suction type fans. Next, we installed the fan in a scale model of the new cooling system. The performance of this double suction type fan was different to that of a single suction type. It is considered that the effect of interaction of the exit flows from the two different fans caused this performance change. The test model installed in an engine compartment showed that this cooling system reduced the area of air inlets and outlets around the engine and did not cause re-circulation of cooling air. (author)

  7. On synthesis and optimization of cooling water systems with multiple cooling towers

    CSIR Research Space (South Africa)

    Gololo, KV

    2011-01-01

    Full Text Available -1 On Synthesis and Optimization of Cooling Water Systems with Multiple Cooling Towers Khunedi Vincent Gololo?? and Thokozani Majozi*? ? Department of Chemical Engineering, University of Pretoria, Lynnwood Road, Pretoria, 0002, South Africa ? Modelling...

  8. Emergency cooling system for a liquid metal cooled reactor

    International Nuclear Information System (INIS)

    Murata, Ryoichi; Fujiwara, Toshikatsu.

    1980-01-01

    Purpose: To suitably cool liquid metal as coolant in emergency in a liquid metal cooled reactor by providing a detector for the pressure loss of the liquid metal passing through a cooling device in a loop in which the liquid metal is flowed and communicating the detector with a coolant flow regulator. Constitution: A nuclear reactor is stopped in nuclear reaction by control element or the like in emergency. If decay heat is continuously generated for a while and secondary coolant is insufficiently cooled with water or steam flowed through a steam and water loop, a cooler is started. That is, low temperature air is supplied by a blower through an inlet damper to the cooler to cool the secondary coolant flowed into the cooler through a bypass pipe so as to finally safely stop an entire plant. Since the liquid metal is altered in its physical properties by the temperature at this time, it is detected to regulate the opening of the valve of the damper according to the detected value. (Sekiya, K.)

  9. Stochastic cooling with a double rf system

    International Nuclear Information System (INIS)

    Wei, Jie.

    1992-01-01

    Stochastic cooling for a bunched beam of hadrons stored in an accelerator with a double rf system of two different frequencies has been investigated. The double rf system broadens the spread in synchrotron-oscillation frequency of the particles when they mostly oscillate near the center of the rf bucket. Compared with the ease of a single rf system, the reduction rates of the bunch dimensions are significantly increased. When the rf voltage is raised, the reduction rate, instead of decreasing linearly, now is independent of the ratio of the bunch area to the bucket area. On the other hand, the spread in synchrotron-oscillation frequency becomes small with the double rf system, if the longitudinal oscillation amplitudes of the particles are comparable to the dimension of the rf bucket. Consequently, stochastic cooling is less effective when the bunch area is close to the bucket area

  10. Low-dose hydrogen peroxide application in closed recirculating aquaculture systems

    DEFF Research Database (Denmark)

    Pedersen, Lars-Flemming; Good, C.; Pedersen, Per Bovbjerg

    2012-01-01

    biofilter nitrite oxidation in low-intensity RAS but not in high-intensity RAS. The impact of HP exposure time on biofilter nitrification capacity was then assessed in biofilter bench-scale experiments with nitrite spiking. Exposure time was found to significantly affect nitrite oxidation. Compared...... with unexposed biofilter elements, nitrite oxidation was reduced more than 90% following 3 h of exposure to 15 mg HP/L, whereas 30 min of exposure had only minor negative effects on nitrite oxidation. The findings of this study demonstrate the potential for developing HP water treatment practices for RAS...... and contradict prevailing notions that HP cannot be used safely in RAS that employ biofiltration. The development of effective new HP treatment protocols for recirculating aquaculture could reduce the current dependence on formalin to improve water quality and control parasitic loads...

  11. James A. FitzPatrick Nuclear Power Plant recirculation pumps vibration system installation and performance since July 7, 1990

    International Nuclear Information System (INIS)

    Lefter, J.

    1992-01-01

    James A. FitzPatrick recirculation pumps are vertical units consisting of General Electric 5,300 hp variable speed motors driving Byron Jackson Pumps. Speed range is from 400 rpm at 20% reactor power to 1,480 rpm at 100% power. Full speed pump output is 42,500 gpm at 530 ft. head. This paper describes the vibration monitoring system. The design of this vibration monitoring system took about five months and was installed during plant refueling outage between February and May 1990. The objectives of this project were as follows: (1) document and assess the mechanical condition of each RRP during plant startup normal operation and shutdown; (2) identify any areas of operation that might be harmful to the unit; (3) perform impact testing of the proximity probe brackets to determine if any bracket resonances existed in the 0 to 20 times operating speed region (0 to 20X); (4) define and recommend Acceptance Regions in the TDM system

  12. Field evaluation of a horizontal well recirculation system for groundwater treatment: Pilot test at the Clean Test Site Portsmouth Gaseous Diffusion Plant, Piketon, Ohio

    International Nuclear Information System (INIS)

    Muck, M.T.; Kearl, P.M.; Siegrist, R.L.

    1998-01-01

    This report presents the results of field testing a horizontal well recirculation system at the Portsmouth Gaseous Diffusion Plant (PORTS). The recirculation system uses a pair of horizontal wells, one for groundwater extraction and treatment and the other for reinjection of treated groundwater, to set up a recirculation flow field. The induced flow field from the injection well to the extraction well establishes a sweeping action for the removal and treatment of groundwater contaminants. The overall purpose of this project is to study treatment of mixed groundwater contaminants that occur in a thin water-bearing zone not easily targeted by traditional vertical wells. The project involves several research elements, including treatment-process evaluation, hydrodynamic flow and transport modeling, pilot testing at an uncontaminated site, and pilot testing at a contaminated site. The results of the pilot test at an uncontaminated site, the Clean Test Site (CTS), are presented in this report

  13. Optimizing cooling systems in Egyptian arid urbans

    International Nuclear Information System (INIS)

    Medhat, Ahmed A.; Khalil, Essam E.

    2006-01-01

    Present study is devoted to climatic and site oriented investigations that were carried out in a new rural development in the Upper-Egypt. Bioclimatic classifications considered Upper Egypt region, near Sudan border, as a Hot and Dry climatic region. [1]. that is affected by solar heat intensities that can reach 900 W/m2 for a period ranged from 5-to-7 hours per day with the presence of study storms. Cooling season extends up to eight months per year having Upper-day-bulb temperature ranged from 400 degree centigrade - to - 470 degree centigrade while Lower-dry-bulb-temperature ranged from 280 degree centigrade - to - 320 degree centigrade with the relative humidity ranged from 10%-to-37% RH. [2]. Site surveys and field experimental and analyses of the commonly used cooling systems were investigated, evaluated and optimized for optimum indoor comfort conditions at efficient energy efficiency. [3]. Extensive analyses were performed based on Psychrometric formulae to evaluate the impact of energy consumptions related to different cooling systems such as direct expansion, chilled water, and evaporative systems. the present study enables the critical investigations of the influence of arid outdoor conditions and the required indoor thermal parameters on the energy efficiencies of HVAC-system. This work; focuses on the suggestion of suitable system that should be implemented by local energy codes in these arid urban.(Author)

  14. An active cooling system for photovoltaic modules

    International Nuclear Information System (INIS)

    Teo, H.G.; Lee, P.S.; Hawlader, M.N.A.

    2012-01-01

    The electrical efficiency of photovoltaic (PV) cell is adversely affected by the significant increase of cell operating temperature during absorption of solar radiation. A hybrid photovoltaic/thermal (PV/T) solar system was designed, fabricated and experimentally investigated in this work. To actively cool the PV cells, a parallel array of ducts with inlet/outlet manifold designed for uniform airflow distribution was attached to the back of the PV panel. Experiments were performed with and without active cooling. A linear trend between the efficiency and temperature was found. Without active cooling, the temperature of the module was high and solar cells can only achieve an efficiency of 8–9%. However, when the module was operated under active cooling condition, the temperature dropped significantly leading to an increase in efficiency of solar cells to between 12% and 14%. A heat transfer simulation model was developed to compare to the actual temperature profile of PV module and good agreement between the simulation and experimental results is obtained.

  15. The effect of recirculating aquaculture systems on the concentrations of heavy metals in culture water and tissues of Nile tilapia Oreochromis niloticus

    NARCIS (Netherlands)

    Martins, C.I.; Eding, E.H.; Verreth, J.A.J.

    2011-01-01

    To date, farming fish in recirculating aquaculture systems (RAS) is one of the most environmentally friendly ways of producing fish. However, with the trend towards intensification, and consequently decrease in water exchange rates, these systems may accumulate substances, such as heavy metals, in

  16. Emergency cooling system for the PHENIX reactor

    International Nuclear Information System (INIS)

    Megy, J.M.; Giudicelli, A.G.; Robert, E.A.; Crette, J.P.

    Among various engineered safeguards of the reactor plant, the authors describe the protective system designed to remove the decay heat in emergency, in case of complete loss of all normal decay heat removal systems. First the normal decay heat rejection systems are presented. Incidents leading to the loss of these normal means are then analyzed. The protective system and its constructive characteristics designed for emergency cooling and based on two independent and highly reliable circuits entirely installed outside the primary containment vessel are described

  17. Cooling system for auxiliary systems of a nuclear power plant

    International Nuclear Information System (INIS)

    Maerker, W.; Mueller, K.; Roller, W.

    1981-01-01

    From the reactor auxiliary and ancillary systems of a nuclear facility heat has to be removed without the hazard arising that radioactive liquids or gases may escape from the safe area of the nuclear facility. A cooling system is described allowing at every moment to make available cooling fluid at a temperature sufficiently low for heat exchangers to be able to remove the heat from such auxiliary systems without needing fresh water supply or water reservoirs. For this purpose a dry cooling tower is connected in series with a heat exchanger that is cooled on the secondary side by means of a refrigerating machine. The cooling pipes are filled with a nonfreezable fluid. By means of a bypass a minimum temperature is guaranteed at cold weather. (orig.) [de

  18. Composition shift in liquid-recirculation refrigerating systems: an experimental investigation for the pure fluid R134a and the mixture R32/134a

    Energy Technology Data Exchange (ETDEWEB)

    Giuliani, G.; Marchesi Donati, F.; Polonara, F. [Ancona Univ. (Italy). Dip. di Energetica; Hewitt, N.J. [University of Ulster at Coleraine, Northern Ireland (United Kingdom). NICERT

    1999-09-01

    The ability of zeotropic mixtures with a remarkable temperature glide to operate in liquid-recirculation systems is investigated and the results of an experimental comparison between the performances of the pure fluid R134a and the zeotropic mixture R32/134a (25/75% by mass) are presented. R134a performs slightly better in the liquid-recirculation mode than in the traditional dry-expansion mode; on the other hand, liquid-recirculation configuration has a detrimental effect on the zeotropic mixture's performance. The reason for this detrimental effect is the mixture component separation which occurs at the liquid/vapor separator. The effect of this separation is investigated using gas chromatograph analysis.

  19. Low pressure cooling seal system for a gas turbine engine

    Science.gov (United States)

    Marra, John J

    2014-04-01

    A low pressure cooling system for a turbine engine for directing cooling fluids at low pressure, such as at ambient pressure, through at least one cooling fluid supply channel and into a cooling fluid mixing chamber positioned immediately downstream from a row of turbine blades extending radially outward from a rotor assembly to prevent ingestion of hot gases into internal aspects of the rotor assembly. The low pressure cooling system may also include at least one bleed channel that may extend through the rotor assembly and exhaust cooling fluids into the cooling fluid mixing chamber to seal a gap between rotational turbine blades and a downstream, stationary turbine component. Use of ambient pressure cooling fluids by the low pressure cooling system results in tremendous efficiencies by eliminating the need for pressurized cooling fluids for sealing this gap.

  20. Performance of Nile tilapia Oreochromis niloticus fingerlings in a hyper-intensive recirculating aquaculture system with low water exchange

    Directory of Open Access Journals (Sweden)

    M Gullian-Klanian

    2013-03-01

    Full Text Available The aim of this paper was evaluate the performance of Nile tilapia fingerlings (Oreochromis niloticus raised at hyper intensive stocking density in a recirculating aquaculture system (RAS with minimum water replacing. The experimental system was performed in a single-batch nursery system to obtain 50 g fish size in 60 days. Fish (2.07 ± 0.04 g were stocked in triplicate at 400 (T1, 500 (T2 and 600 (T3 fish m-3 (0.84, 1.05, 1.22 kg m-3. RAS functioned with 12,000 L of recirculating water and 252 L day-1of water replacing (2.1% daily. The efficiency of the biofilter for removing the total ammonia nitrogen (TAN was 48 ± 12.5 mg L-1. Stocking density did not affect significantly the survival (89.5 to 93.6%. The growth rate of T1 (0.96 g day-1; 5.01% day-1 and T2 (0.92 g day-1; 4.95 % day-1 was significantly higher than T3 (0.83 g day-1; 4.80% day-1. The specific growth rate (SGR of T1 was 41% influenced by temperature. For T2 and T3 the SGR were influenced by the variation of dissolved oxygen (DO that explained 47 and 44% of the fish weight variation, respectively. The SGR from T3 was also affected by the concentration of ammonia nitrogen (31%. The high stocking density affected the overall size of fish and the size homogeneity, but had no negative effect on the length-weight relationship (L-W. Data support the conclusion that fingerling stocked at 400 and 500 fish m-3 shows high performance during 9-weeks when the biomass not exceed 37 kg m-3. At this time fish have reached the desired final nursery weight (50 g for transfer to grow-out facilities.

  1. Peracetic acid is a suitable disinfectant for recirculating fish-microalgae integrated multi-trophic aquaculture systems

    Directory of Open Access Journals (Sweden)

    Dibo Liu

    2016-11-01

    Full Text Available Integrated multi-trophic aquaculture (IMTA is a promising direction for the sustainable development of aquaculture. Microalgae have good potential to be integrated with recirculating aquaculture systems because they can use the nitrogen excreted from fish and share the same optimal pH value as in aquaculture. As a byproduct, the microalgae biomass can be used for fish feed or biofuel. However, the recirculating fish-microalgae IMTA system is under constant threat from fish pathogens and phytoplankton-lytic bacteria. Therefore, it is necessary to apply proper disinfectants as prophylaxis or treatment which are effective against these threats, but safe to fish and microalgae. For this purpose, peracetic acid (PAA is a valid option because it is highly effective against fish pathogens and bacteria at low concentrations and degrades spontaneously to harmless residues. In the present study, we exposed the culture of a marine microalgae Tetraselmis chuii once per day for four days to four PAA products with differing hydrogen peroxide (H2O2/PAA proportions at two concentrations (1 and 2 mg L−1 PAA. The H2O2 solutions at equivalent total peroxide (H2O2 + PAA concentrations were tested in parallel. The results show that the growth and photosynthesis of T. chuii were not affected by three of the PAA products (Wofasteril® E400, Wofasteril® E250 and Applichem® 150 and equivalent H2O2 solutions at both concentrations. In contrast, Wofasteril® Lspez and an equivalent H2O2 solution at both concentrations caused irreversible culture collapse, photosynthesis dysfunction and irreversible cell damage. In conclusion, PAA products with low proportions of H2O2 are optimal disinfectants for fish-microalgae IMTA systems.

  2. Comparison Between Conventional Design and Cathode Gas Recirculation Design of a Direct-Syngas Solid Oxide Fuel Cell–Gas Turbine Hybrid Systems Part I: Design Performance

    Directory of Open Access Journals (Sweden)

    Vahid Azami

    2017-06-01

    Keywords: Solid oxide fuel cell, Gas turbine, Cathode gas recirculation, Exergy. Article History: Received Feb 23rd 2017; Received in revised form May 26th 2017; Accepted June 1st 2017; Available online How to Cite This Article: Azami, V, and Yari, M. (2017 Comparison between conventional design and cathode gas recirculation design of a direct-syngas solid oxide fuel cell–gas turbine hybrid systems part I: Design performance. International Journal of Renewable Energy Develeopment, 6(2, 127-136. https://doi.org/10.14710/ijred.6.2.127-136

  3. Controlled cooling of an electronic system based on projected conditions

    Science.gov (United States)

    David, Milnes P.; Iyengar, Madhusudan K.; Schmidt, Roger R.

    2015-08-18

    Energy efficient control of a cooling system cooling an electronic system is provided based, in part, on projected conditions. The control includes automatically determining an adjusted control setting(s) for an adjustable cooling component(s) of the cooling system. The automatically determining is based, at least in part, on projected power consumed by the electronic system at a future time and projected temperature at the future time of a heat sink to which heat extracted is rejected. The automatically determining operates to reduce power consumption of the cooling system and/or the electronic system while ensuring that at least one targeted temperature associated with the cooling system or the electronic system is within a desired range. The automatically determining may be based, at least in part, on an experimentally obtained model(s) relating the targeted temperature and power consumption of the adjustable cooling component(s) of the cooling system.

  4. Loss-of-coolant and loss-of-flow accident in the ITER-EDA first wall/blanket cooling system

    Energy Technology Data Exchange (ETDEWEB)

    Komen, E.M.J.; Koning, H.

    1995-05-01

    This report presents the analysis of the transient thermal-hydraulic system behaviour inside the first wall/blanket cooling system and the resulting temperature response inside the first wall and blanket of the ITER-EDA (International Thermonuclear Experimental Reactor - Engineering Design Activities) reactor design during a: - Loss-of-coolant accident caused by a reputure of the pump suction pipe; - loss-of-flow accident caused by a trip of the recirculation pump. (orig.).

  5. Loss-of-coolant and loss-of-flow accident in the ITER-EDA first wall/blanket cooling system

    International Nuclear Information System (INIS)

    Komen, E.M.J.; Koning, H.

    1995-05-01

    This report presents the analysis of the transient thermal-hydraulic system behaviour inside the first wall/blanket cooling system and the resulting temperature response inside the first wall and blanket of the ITER-EDA (International Thermonuclear Experimental Reactor - Engineering Design Activities) reactor design during a: - Loss-of-coolant accident caused by a reputure of the pump suction pipe; - loss-of-flow accident caused by a trip of the recirculation pump. (orig.)

  6. Investigation of the Makeup, Source, and Removal Strategies for Total Organic Carbon in the Oxygen Generation System Recirculation Loop

    Science.gov (United States)

    Bowman, Elizabeth M.; Carpenter, Joyce; Roy, Robert J.; Van Keuren, Steve; Wilson, Mark E.

    2015-01-01

    Since 2007, the Oxygen Generation System (OGS) on board the International Space Station (ISS) has been producing oxygen for crew respiration via water electrolysis. As water is consumed in the OGS recirculating water loop, make-up water is furnished by the ISS potable water bus. A rise in Total Organic Carbon (TOC) was observed beginning in February, 2011, which continues through the present date. Increasing TOC is of concern because the organic constituents responsible for the TOC were unknown and had not been identified; hence their impacts on the operation of the electrolytic cell stack components and on microorganism growth rates and types are unknown. Identification of the compounds responsible for the TOC increase, their sources, and estimates of their loadings in the OGA as well as possible mitigation strategies are presented.

  7. Growth of juvenile Atlantic cod Gadus morhua in land-based recirculation systems: Effects of feeding regime, photoperiod and diet

    DEFF Research Database (Denmark)

    Fülberth, Michael; Moran, Damian; Jarlbæk, Henrik

    2009-01-01

    The combined effect of feeding regime and photoperiod on the growth of juvenile Atlantic cod Gadus morhua in land-based recirculating aquaculture systems (RAS) was examined using three different commercial diets. Fish of 8–10 g were reared in 1 m3 tanks at an initial density of 10 kg m− 3 for 78 d....... Three RAS units were used to simultaneously test three feed/photoperiod regimes that might be encountered in the wild or aquaculture; LightDark (LD) 24:0, LD12:11 (+ 1 h crepuscular periods) and LD6:6 (+ 12 h crepuscular periods). Feed was administered during the light period every 30 min for a 3 min...... concentrations (photoperiod regime and diet on specific growth rate (SGR). Fish receiving the LD12:11 and LD6:6 regimes and Diet A grew best (SGR 2.59 and 2.54% d− 1 respectively). Fish...

  8. Safety system consideration of a supercritical-water cooled fast reactor with simplified PSA

    International Nuclear Information System (INIS)

    Lee, J.H.; Oka, Y.; Koshizuka, S.

    1999-01-01

    The probabilistic safety of the supercritical-water cooled fast reactor (SCFR) is evaluated with the simplified probabilistic safety assessment (PSA) methodology. SCFR has a once-through direct cycle where all feedwater flows through the core to the turbine at supercritical pressure. There are no recirculation loops in the once-through direct cycle system, which is the most important difference from the current light water reactor (LWR). The main objective of the present study is to assess the effect of this difference on the safety in the stage of conceptual design study. A safety system configuration similar to the advanced boiling water reactor (ABWR) is employed. At loss of flow events, no natural recirculation occurs. Thus, emergency core flow should be quickly supplied before the completion of the feedwater pump coastdown at a loss of flow accident. The motor-driven high pressure coolant injection (MD-HPCI) system cannot be used for the quick core cooling due to the delay of the emergency diesel generator (D/G) start-up. Accordingly, an MD-HPCI system in an ABWR is substituted by a turbine-driven (TD-) HPCI system for the SCFR. The calculated core damage frequency (CDF) is a little higher than that of the Japanese ABWR and a little lower than that of the Japanese BWR when Japanese data are employed for initiating event frequencies. Four alternatives to the safety system configurations are also examined as a sensitivity analysis. This shows that the balance of the safety systems designed here is adequate. Consequently, though the SCFR has a once-through coolant system, the CDF is not high due to the diversity of feedwater systems as the direct cycle characteristics

  9. Emergency reactor cooling systems for the experimental VHTR

    International Nuclear Information System (INIS)

    Mitake, Susumu; Suzuki, Katsuo; Miyamoto, Yoshiaki; Tamura, Kazuo; Ezaki, Masahiro.

    1983-03-01

    Performances and design of the panel cooling system which has been proposed to be equipped as an emergency reactor cooling system for the experimental multi purpose very high temperature gas-cooled reactor are explained. Effects of natural circulation flow which would develop in the core and temperature transients of the panel in starting have been precisely investigated. Conditions and procedures for settling accidents with the proposed panel cooling system have been also studied. Based on these studies, it has been shown that the panel cooling system is effective and useful for the emergency reactor cooling of the experimental VHTR. (author)

  10. Association between trichodiniasis in eel ( Anguilla anguilla ) and water quality in recirculation systems

    DEFF Research Database (Denmark)

    Madsen, H.C.K.; Buchmann, K.; Mellergaard, Stig

    2000-01-01

    Association between various water quality parameters and the infection level of Trichodina jadranica in cultured eels were examined in nine recirculation farms in Denmark. Production units suffering from trichodiniasis (n = 4) had relatively high contents of organic dry matter (13-65 mg l(-1)), low...... concentrations of nitrate (150-500 mg NO3 l(-1)) and high pH (6.2-7.4) in the process water compared to farms without Trichodina problems (n = 5), which had a relatively low load of organic dry matter (9-16 mg l(-1)), high nitrate concentration (250-900 mg NO3 l(-1)) and a low pH (5.3-6.9). More detailed studies...... of the effect of water parameters on the infection level were conducted in two production units suffering from frequent outbreaks of trichodiniasis. In one production unit, the high and highly varying content of organic dry matter (21- 83 mg l(-1)) was significantly and positively correlated (r = 0.37, p

  11. Effect of mass transfer in a recirculation batch reactor system for immobilized penicillin amidase.

    Science.gov (United States)

    Park, J M; Choi, C Y; Seong, B L; Han, M H

    1982-10-01

    The effect of external mass transfer resistance on the overall reaction rate of the immobilized whole cell penicillin amidase of E. coli in a recirculation batch reactor was investigated. The internal diffusional resistance was found negligible as indicated by the value of effectiveness factor, 0.95. The local environmental change in a column due to the pH drop was successfully overcome by employing buffer solution. The reaction rate was measured by pH-stat method and was found to follow the simple Michaelis-Menten law at the initial stage of the reaction. The values of the net reaction rate experimentally determined were used to calculate the substrate concentration at the external surface of the catalyst pellet and then to calculate the mass transfer coefficient, k(L), at various flow rates and substrate concentrations. The correlation proposed by Chilton and Colburn represented adequately the experimental data. The linear change of log j(D) at low log N(Re) with negative slope was ascribed to the fact that the external mass transfer approached the state of pure diffusion in the limit of zero superficial velocity.

  12. Metal foams as gas coolers for exhaust gas recirculation systems subjected to particulate fouling

    International Nuclear Information System (INIS)

    Hooman, K.; Malayeri, M.R.

    2016-01-01

    Highlights: • Fouling of metal foam heat exchangers as EGR gas coolers is tested. • An optimal design was inferred based on the generated data. • A simple cleaning technique was suggested and evaluated. - Abstract: This paper presents experimental results indicating the benefits and challenges associated with the use of metal foams as Exhaust Gas Recirculation (EGR) coolers. Fouling of such heat exchangers is a critical issue and, as such, special attention has been paid to address this very issue in the present study where a soot generator has been employed to simulate the engine running condition. Effects of aluminium foam PPI and height as well as gas velocity are investigated. It has been noted that proper design of the foam can lead to significantly higher heat transfer rate and reasonable pressure drop compared to no-foam cases. More interestingly, it is demonstrated that the foams can be cleaned easily without relying on expensive cleaning techniques. Using simple brush-cleaning, the foams can be reused as EGR gas coolers with a performance penalty of only 17% (compared to a new or clean foam).

  13. Electromechanically cooled germanium radiation detector system

    International Nuclear Information System (INIS)

    Lavietes, Anthony D.; Joseph Mauger, G.; Anderson, Eric H.

    1999-01-01

    We have successfully developed and fielded an electromechanically cooled germanium radiation detector (EMC-HPGe) at Lawrence Livermore National Laboratory (LLNL). This detector system was designed to provide optimum energy resolution, long lifetime, and extremely reliable operation for unattended and portable applications. For most analytical applications, high purity germanium (HPGe) detectors are the standard detectors of choice, providing an unsurpassed combination of high energy resolution performance and exceptional detection efficiency. Logistical difficulties associated with providing the required liquid nitrogen (LN) for cooling is the primary reason that these systems are found mainly in laboratories. The EMC-HPGe detector system described in this paper successfully provides HPGe detector performance in a portable instrument that allows for isotopic analysis in the field. It incorporates a unique active vibration control system that allows the use of a Sunpower Stirling cycle cryocooler unit without significant spectral degradation from microphonics. All standard isotopic analysis codes, including MGA and MGA++, GAMANL, GRPANL and MGAU, typically used with HPGe detectors can be used with this system with excellent results. Several national and international Safeguards organisations including the International Atomic Energy Agency (IAEA) and U.S. Department of Energy (DOE) have expressed interest in this system. The detector was combined with custom software and demonstrated as a rapid Field Radiometric Identification System (FRIS) for the U.S. Customs Service . The European Communities' Safeguards Directorate (EURATOM) is field-testing the first Safeguards prototype in their applications. The EMC-HPGe detector system design, recent applications, and results will be highlighted

  14. Modelling aerosol behavior in reactor cooling systems

    International Nuclear Information System (INIS)

    McDonald, B.H.

    1990-01-01

    This paper presents an overview of some of the areas of concern in using computer codes to model fission-product aerosol behavior in the reactor cooling system (RCS) of a water-cooled nuclear reactor during a loss-of-coolant accident. The basic physical processes that require modelling include: fission product release and aerosol formation in the reactor core, aerosol transport and deposition in the reactor core and throughout the rest of the RCS, and the interaction between aerosol transport processes and the thermalhydraulics. In addition to these basic physical processes, chemical reactions can have a large influence on the nature of the aerosol and its behavior in the RCS. The focus is on the physics and the implications of numerical methods used in the computer codes to model aerosol behavior in the RCS

  15. Evaluating the chronic effects of nitrate on the health and performance of post-smolt Atlantic salmon Salmo salar in freshwater recirculation aquaculture systems

    Science.gov (United States)

    Commercial production of Atlantic salmon smolts, post-smolts, and market-size fish using land-based recirculation aquaculture systems (RAS) is expanding. RAS generally provide a nutrient-rich environment in which nitrate accumulates as an end-product of nitrification. An 8-month study was conducted ...

  16. Fillet quality and processing attributes of postsmolt Atlantic salmon, Salmo salar, fed a fishmeal-free diet and a fishmeal-based diet in recirculation aquaculture systems

    Science.gov (United States)

    Many studies have evaluated the adequacy of alternate ingredient diets for Atlantic salmon, Salmo salar, mainly with focus on fish performance and health; however, comprehensive analysis of fillet quality is lacking, particularly for salmon fed these diets in recirculation aquaculture systems (RAS)....

  17. Stressing fish in Recirculating Aquaculture Systems (RAS): Does stress induced in one group of fish affect the feeding motivation of other fish sharing the same RAS?

    NARCIS (Netherlands)

    Martins, C.I.; Eding, E.H.; Verreth, J.A.J.

    2011-01-01

    As a consequence of water re-use and high stocking densities, Recirculating Aquaculture Systems (RAS) may lead to an accumulation of substances released by the fish into the water, e.g. cortisol and alarm pheromones. This study investigated the effect of stressing fish on the feeding motivation of

  18. Effects of semi-continous peracetic acid dosing on rainbow trout Oncorhynchus mykiss performance, water quality, and off-flavor compounds in recirculation aquaculture systems

    Science.gov (United States)

    Water clarifying and disinfection techniques such as ozonation and ultraviolet irradiation are commonly used in recirculation aquaculture systems (RAS); however, the capital and operating costs of these technologies are expensive. Cost-effective treatment options that maintain fish health and simult...

  19. The effects of ozone and water exchange rates on water quality and rainbow trout Oncorhynchus mykiss performance in replicated water recirculating systems

    Science.gov (United States)

    Rainbow trout Oncorhynchus mykiss performance and water quality were evaluated and compared within six replicated 9.5 cubic meter water recirculating aquaculture systems (WRAS) operated with and without ozone at various water exchange rates. Three separate studies were conducted: 1) low water exchan...

  20. Flavobacterium branchiophilum and F. succinicans associated with bacterial gill disease in rainbow trout Oncorhynchus mykiss (Walbaum) in water recirculation aquaculture systems

    Science.gov (United States)

    Raised rainbow trout Oncorhynchus mykiss in six replicated water recirculation aquaculture systems (WRAS), and manipulated environmental conditions to promote bacterial gill disease (BGD). For each episode of BGD, gill tissue was sampling from affected fish, unaffected fish within the same WRAS, and...

  1. Comparing the effects of high vs. low nitrate on the health, performance, and welfare of juvenile rainbow trout Oncorhynchus mykiss within water recirculating aquaculture systems

    Science.gov (United States)

    Previous research indicates that rainbow trout (Oncorhynchus mykiss) begin to exhibit health and welfare problems when cultured within water recirculating aquaculture systems (WRAS) operated at low exchange (6.7 days hydraulic retention time) and a mean feed loading rate of 4.1 kg feed/m3 daily make...

  2. Evaluation of ozonation on levels of the off-flavor compounds geosmin and 2-methylisoborneol in water and rainbow trout Oncorhynchus mykiss from water recirculation aquaculture systems

    Science.gov (United States)

    Common “off-flavors” in fish cultured in water recirculation aquaculture systems (WRAS) are “earthy” and “musty” due to the presence of the off-flavor metabolites geosmin and 2-methylisoborneol (MIB), respectively. Previously, ozone addition has been applied to WRAS at relatively low doses to break...

  3. Long-Haul Dense Space Division Multiplexed Transmission over Low-Crosstalk Heterogeneous 32-Core Transmission Line Using Partial Recirculating Loop System

    DEFF Research Database (Denmark)

    Mizuno, Takayuki; Shibahara, Kohki; Ye, Feihong

    2017-01-01

    In this paper, we present long-haul 32-core dense space division multiplexed (DSDM) unidirectional transmission over a single-mode multicore transmission line. We developed a low-crosstalk heterogeneous 32-core fiber with a square lattice arrangement, and a novel partial recirculating loop system...

  4. Cooling Tower (Evaporative Cooling System) Measurement and Verification Protocol

    Energy Technology Data Exchange (ETDEWEB)

    Kurnik, Charles W. [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Boyd, Brian [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Stoughton, Kate M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Lewis, Taylor [Colorado Energy Office, Denver, CO (United States)

    2017-12-05

    This measurement and verification (M and V) protocol provides procedures for energy service companies (ESCOs) and water efficiency service companies (WESCOs) to determine water savings resulting from water conservation measures (WCMs) in energy performance contracts associated with cooling tower efficiency projects. The water savings are determined by comparing the baseline water use to the water use after the WCM has been implemented. This protocol outlines the basic structure of the M and V plan, and details the procedures to use to determine water savings.

  5. Cooling system for the IFMIF-EVEDA radiofrequency system

    International Nuclear Information System (INIS)

    Perez Pichel, G. D.

    2012-01-01

    The IFMIF-EVEDA project consists on an accelerator prototype that will be installed at Rokkasho (Japan). Through CIEMAT, that is responsible of the development of many systems and components. Empresarios Agrupados get the responsibility of the detailed design of the cooling system for the radiofrequency system (RF system) that must feed the accelerator. the RF water cooling systems is the water primary circuit that provides the required water flow (with a certain temperature, pressure and water quality) and also dissipates the necessary thermal power of all the radiofrequency system equipment. (Author) 4 refs.

  6. Evaluation of heat exchange performance for the auxiliary component cooling water system cooling tower in HTTR

    International Nuclear Information System (INIS)

    Tochio, Daisuke; Kameyama, Yasuhiko; Shimizu, Atsushi; Inoi, Hiroyuki; Yamazaki, Kazunori; Shimizu, Yasunori; Aragaki, Etsushi; Ota, Yukimaru; Fujimoto, Nozomu

    2006-09-01

    The auxiliary component cooling water system (ACCWS) is one of the cooling system in High Temperature Engineering Test Reactor (HTTR). The ACCWS has main two features, many facilities cooling, and heat sink of the vessel cooling system which is one of the engineering safety features. Therefore, the ACCWS is required to satisfy the design criteria of heat removal performance. In this report, heat exchange performance data of the rise-to-power-up test and the in-service operation for the ACCWS cooling tower was evaluated. Moreover, the evaluated values were compared with the design values, and it is confirmed that ACCWS cooling tower has the required heat exchange performance in the design. (author)

  7. Exhaust gas recirculation apparatus for internal combustion engine

    Energy Technology Data Exchange (ETDEWEB)

    Shigemori, M; Eguchi, N

    1975-01-07

    An exhaust gas recirculation device to reduce nitrogen oxides emission from internal combustion engines is described. The recirculation is achieved by employing a tube connecting between the exhaust pipe and intake tube. A throttle valve is installed within the exhaust pipe between the muffler and recirculation tube, and regulated by exhaust gas temperature. Whenever the gas temperature is high, the valve closes and increases the gas flow to the intake tube. A temperature sensor is installed within the exhaust pipe and controls a solenoid or magnetic air valve linking to the throttle valve through a relay. The recirculation tube can be cooled by a fan to improve the engine power.

  8. Effects of elevated atmospheric carbon dioxide concentrations on water and acid requirements of soybeans grown in a recirculating hydroponic system

    Science.gov (United States)

    Mackowiak, C. L.; Wheeler, R. M.; Lowery, W.; Sager, J. C.

    1990-01-01

    Establishing mass budgets of various crop needs, i.e. water and nutrients, in different environments is essential for the Controlled Ecological Life Support System (CELSS). The effects of CO2 (500 and 1000 umol mol (exp -1)) on water and acid use (for pH control) by soybeans in a recirculating hydroponic system were examined. Plants of cvs. McCall and Pixie were grown for 90 days using the nutrient film technique (NFT) and a nitrate based nutrient solution. System acid use for both CO2 levels peaked near 4 weeks during a phase of rapid vegetative growth, but acid use decreased more rapidly under 500 compared to 1000 umol mol (exp GR) CO2. Total system water use by 500 and 1000 umol mol (exp -1) plants was similar, leaving off at 5 weeks and declining as plants senesced (ca. 9 weeks). However, single leaf transpiration rates were consistently lower at 1000 umol mol (exp -1). The data suggest that high CO2 concentrations increase system acid (and nutrient) use because of increased vegetative growth, which in turn negates the benefit of reduced water use (lower transpiration rates) per unit leaf area.

  9. Misting-cooling systems for microclimatic control in public space

    OpenAIRE

    Nunes, Joao; Zoilo, Inaki; Jacinto, Nuno; Nunes, Ana; Torres-Campos, Tiago; Pacheco, Manuel; Fonseca, David

    2011-01-01

    Misting-cooling systems have been used in outdoor spaces mainly for aesthetic purposes, and punctual cooling achievement. However, they can be highly effective in outdoor spaces’ bioclimatic comfort, in terms of microclimatic control, as an evaporative cooling system. Recent concerns in increasing bioclimatic standards in public outdoor spaces, along with more sustainable practices, gave origin to reasoning where plastic principles are combined with the study of cooling efficacy, in order to ...

  10. Investigations of combined used of cooling ponds with cooling towers or spraying systems

    International Nuclear Information System (INIS)

    Farforovsky, V.B.

    1990-01-01

    Based on a brief analysis of the methods of investigating cooling ponds, spraying systems and cooling towers, a conclusion is made that the direct modelling of the combined use of cooling systems listed cannot be realized. An approach to scale modelling of cooling ponds is proposed enabling all problems posed by the combined use of coolers to be solved. Emphasized is the importance of a proper choice of a scheme of including a cooler in a general water circulation system of thermal and nuclear power plants. A sequence of selecting a cooling tower of the type and spraying system of the size ensuring the specified temperature regime in a water circulation system is exemplified by the water system of the Ghorasal thermal power plant in Bangladesh

  11. Implementation of an experimental pilot reproducing the fouling of the exhaust gas recirculation system in diesel engines

    Directory of Open Access Journals (Sweden)

    Crepeau Gérald

    2012-04-01

    Full Text Available The European emission standards EURO 5 and EURO 6 define more stringent acceptable limits for exhaust emissions of new vehicles. The Exhaust Gas Recirculation (EGR system is a partial but essential solution for lowering the emission of nitrogen oxides and soot particulates. Yet, due to a more intensive use than in the past, the fouling of the EGR system is increased. Ensuring the reliability of the EGR system becomes a main challenge. In partnership with PSA Peugeot Citroën, we designed an experimental setup that mimics an operating EGR system. Its distinctive features are (1 its ability to reproduce precisely the operating conditions and (2 its ability to measure the temperature field on the heat exchanger surface with an Infra Red camera for detecting in real time the evolution of the fooling deposit based on its thermal resistance. Numerical codes are used in conjunction with this experimental setup to determine the evolution of the fouling thickness from its thermal resistance.

  12. Cooling Performance Analysis of ThePrimary Cooling System ReactorTRIGA-2000Bandung

    Science.gov (United States)

    Irianto, I. D.; Dibyo, S.; Bakhri, S.; Sunaryo, G. R.

    2018-02-01

    The conversion of reactor fuel type will affect the heat transfer process resulting from the reactor core to the cooling system. This conversion resulted in changes to the cooling system performance and parameters of operation and design of key components of the reactor coolant system, especially the primary cooling system. The calculation of the operating parameters of the primary cooling system of the reactor TRIGA 2000 Bandung is done using ChemCad Package 6.1.4. The calculation of the operating parameters of the cooling system is based on mass and energy balance in each coolant flow path and unit components. Output calculation is the temperature, pressure and flow rate of the coolant used in the cooling process. The results of a simulation of the performance of the primary cooling system indicate that if the primary cooling system operates with a single pump or coolant mass flow rate of 60 kg/s, it will obtain the reactor inlet and outlet temperature respectively 32.2 °C and 40.2 °C. But if it operates with two pumps with a capacity of 75% or coolant mass flow rate of 90 kg/s, the obtained reactor inlet, and outlet temperature respectively 32.9 °C and 38.2 °C. Both models are qualified as a primary coolant for the primary coolant temperature is still below the permitted limit is 49.0 °C.

  13. Switching strategy between HP (high pressure)- and LPEGR (low pressure exhaust gas recirculation) systems for reduced fuel consumption and emissions

    International Nuclear Information System (INIS)

    Luján, José Manuel; Guardiola, Carlos; Pla, Benjamín; Reig, Alberto

    2015-01-01

    EGR (Exhaust gas recirculation) plays a major role in current Diesel internal combustion engines as a cost-effective solution to reduce NO_x emissions. EGR systems will suffer a significant evolution with the introduction of NO_x after-treatment and the proliferation of more complex EGR architectures such as low pressure EGR or dual EGR. In this paper the combination of HPEGR (high pressure EGR) LPEGR (low pressure EGR) is presented as a method to minimise fuel consumption with reduced NO_x emissions. Particularly, the paper proposes to switch between HPEGR and LPEGR architectures depending on the engine operating conditions in order to exploit the potential of both systems. In this sense, given a driving cycle, in the case at hand the NEDC, the proposed strategy seeks the EGR layout to use at each instant of the cycle to minimise the fuel consumption such that NO_x emissions are kept below a certain limit. The experimental results obtained show that combining both EGR systems sequentially along the NEDC allows to keep NO_x emission below a much lower limit with minimum fuel consumption. - Highlights: • The combination of HP–LPEGR reduces the NO_x with a small impact on consumption. • The switching strategy between HP – LPEGR is derived from Optimal Control Theory. • The proposed strategy is validated experimentally.

  14. Performance characteristic of hybrid cooling system based on cooling pad and evaporator

    Science.gov (United States)

    Yoon, J. I.; Son, C. H.; Choi, K. H.; Kim, Y. B.; Sung, Y. H.; Roh, S. J.; Kim, Y. M.; Seol, S. H.

    2018-01-01

    In South Korea, most of domestic animals such as pigs and chickens might die due to thermal diseases if they are exposed to the high temperature consistently. In order to save them from the heat wave, numerous efforts have been carried out: installing a shade net, adjusting time of feeding, spraying mist and setting up a circulation fan. However, these methods have not shown significant improvements. Thus, this study proposes a hybrid cooling system combining evaporative cooler and air-conditioner in order to resolve the conventional problems caused by the high temperature in the livestock industry. The problem of cooling systems using evaporative cooling pads is that they are not effective for eliminating huge heat load due to their limited capacity. And, temperature of the supplied air cannot be low enough compared to conventional air-conditioning systems. On the other hand, conventional air-conditioning systems require relatively expensive installation cost, and high operating cost compared to evaporative cooling system. The hybrid cooling system makes up for the lack of cooling capacity of the evaporative cooler by employing the conventional air-conditioner. Additionally, temperature of supplied air can be lowered enough. In the hybrid cooling system, induced air by a fan is cooled by the evaporation of water in the cooling pad, and it is cooled again by an evaporator in the air-conditioner. Therefore, the more economical operation is possible due to additionally obtained cooling capacity from the cooling pads. Major results of experimental analysis of hybrid cooling system are as follows. The compressor power consumption of the hybrid cooling system is about 23% lower, and its COP is 17% higher than that of the conventional air-conditioners. Regarding the condition of changing ambient temperature, the total power consumption decreased by about 5% as the ambient temperature changed from 28.7°C to 31.7°C. Cooling capacity and COP also presented about 3% and 1

  15. Phasing of Debuncher Stochastic Cooling Transverse Systems

    International Nuclear Information System (INIS)

    Pasquinelli, Ralph

    2000-01-01

    With the higher frequency of the cooling systems in the Debuncher, a modified method of making transfer functions has been developed for transverse systems. (Measuring of the momentum systems is unchanged.) Speed in making the measurements is critical, as the beam tends to decelerate due to vacuum lifetime. In the 4-8 GHz band, the harmonics in the Debuncher are 6,700 to 13,400 times the revolution frequency. Every Hertz change in revolution frequency is multiplied by this harmonic number and becomes a frequency measurement error, which is an appreciable percent of the momentum width of the beam. It was originally thought that a momentum cooling system would be phased first so that the beam could be kept from drifting in revolution frequency. As it turned out, the momentum cooling was so effective (even with the gain turned down) that the momentum width normalized to fo became less than one Hertz on the Schottky pickup. A beam this narrow requires very precise measurement of tune and revolution frequency. It was difficult to get repeatable results. For initial measuring of the transverse arrays, relative phase and delay is all that is required, so the measurement settings outlined below will suffice. Once all input and output arrays are phased, a more precise measurement of all pickups to all kickers can be done with more points and both upper and lower side bands, as in figure 1. Settings on the network analyzer were adjusted for maximum measurement speed. Data is not analyzed until a complete set of measurements is taken. Start and stop frequencies should be chosen to be just slightly wider than the band being measured. For transverse systems, select betatron USB for the measurement type. This will make the measurement two times faster. Select 101 for the number of points, sweep time of 5 seconds, IF bandwidth 30 Hz, averages = 1. It is important during the phasing to continually measure the revolution frequency and beam width of the beam for transverse systems

  16. Deposit control in process cooling water systems

    International Nuclear Information System (INIS)

    Venkataramani, B.

    1981-01-01

    In order to achieve efficient heat transfer in cooling water systems, it is essential to control the fouling of heat exchanger surfaces. Solubilities of scale forming salts, their growth into crystals, and the nature of the surfaces play important roles in the deposition phenomenon. Condensed phosphates, organic polymers and compounds like phosphates are effective in controlling deposition of scale forming salts. The surface active agents inhibit crystal growth and modify the crystals of the scale forming salts, and thus prevent deposition of dense, uniformly structured crystalline mass on the heat transfer surface. Understanding the mechanism of biofouling is essential to control it by surface active agents. Certain measures taken in the plant, such as back flushing, to control scaling, sometimes may not be effective and can be detrimental to the system itself. (author)

  17. Thermal Sizing of Heat Exchanger Tubes for Air Natural Convective Cooling System of Emergency Cooling Tank

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Myoung Jun; Lee, Hee Joon [Kookmin Univ., Seoul (Korea, Republic of); Moon, Joo Hyung; Bae, Youngmin; Kim, Youngin [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    For the long operation of secondary passive cooling system, however, water level goes down by evaporation in succession at emergency cooling tank. At the end there would be no place to dissipate heat from condensation heat exchanger. Therefore, steam cooling heat exchanger is put on the top of emergency cooling tank to maintain appropriate water level by collecting evaporating steam. Steam cooling heat exchanger is installed inside an air chimney and evaporated steam is cooled down by air natural convection. In this study, thermal sizing of steam cooling heat exchanger under air natural convection was conducted by TSCON program for the design of experimental setup as shown in Fig. 2. Thermal sizing of steam cooling heat exchanger tube under air natural convection was conducted by TSCON program for the design of experimental setup. 25 - 1' tubes which has a length 1687 mm was determined as steam cooling heat exchanger at 2 kW heat load and 100 liter water pool in emergency cooling tank (experimental limit condition). The corresponding width of two tubes is 50 mm and has 5 by 5 tube array for heat exchanger.

  18. Thermal Sizing of Heat Exchanger Tubes for Air Natural Convective Cooling System of Emergency Cooling Tank

    International Nuclear Information System (INIS)

    Kim, Myoung Jun; Lee, Hee Joon; Moon, Joo Hyung; Bae, Youngmin; Kim, Youngin

    2014-01-01

    For the long operation of secondary passive cooling system, however, water level goes down by evaporation in succession at emergency cooling tank. At the end there would be no place to dissipate heat from condensation heat exchanger. Therefore, steam cooling heat exchanger is put on the top of emergency cooling tank to maintain appropriate water level by collecting evaporating steam. Steam cooling heat exchanger is installed inside an air chimney and evaporated steam is cooled down by air natural convection. In this study, thermal sizing of steam cooling heat exchanger under air natural convection was conducted by TSCON program for the design of experimental setup as shown in Fig. 2. Thermal sizing of steam cooling heat exchanger tube under air natural convection was conducted by TSCON program for the design of experimental setup. 25 - 1' tubes which has a length 1687 mm was determined as steam cooling heat exchanger at 2 kW heat load and 100 liter water pool in emergency cooling tank (experimental limit condition). The corresponding width of two tubes is 50 mm and has 5 by 5 tube array for heat exchanger

  19. CoolPack – Simulation tools for refrigeration systems

    DEFF Research Database (Denmark)

    Jakobsen, Arne; Rasmussen, Bjarne D.; Andersen, Simon Engedal

    1999-01-01

    CoolPack is a collection of programs used for energy analysis and optimisation of refrigeration systems. CoolPack is developed at the Department of Energy Engineering at the Technical University of Denmark. The Danish Energy Agency finances the project. CoolPack is freeware and can be downloaded...

  20. Renewal of cooling system of JMTR

    International Nuclear Information System (INIS)

    Onoue, Ryuji; Kawamata, Takanori; Otsuka, Kaoru; Koike, Sumio; Nishiyama, Yutaka; Fukasaku, Akitomi

    2011-06-01

    The Japan Materials Testing Reactor (JMTR) is a light water moderated and cooled tank-type reactor, and its thermal power is 50 MW. The JMTR is categorized as high flux testing reactors in the world. The JMTR has been utilized for irradiation experiments of nuclear fuels and materials, as well as for radioisotope productions since the first criticality in March 1968 until August 2006. JAEA decided to refurbish the JMTR as an important fundamental infrastructure to promote the nuclear research and development. The refurbishment work was started from 2007, and restart is planned in 2011. Renewal facilities were selected from evaluation on their damage and wear in terms of aging. Facilities whose replacement parts are no longer manufactured or not likely to be manufactured continuously in near future, are selected as renewal ones. Replacement priority was decided with special attention to safety concerns. A monitoring of aging condition by the regular maintenance activity is an important factor in selection of continuous using after the restart. In this report, renewal of the cooling system within refurbishment facilities in the JMTR is summarized. (author)

  1. Synergistic Effects of Micro-electrolysis-Photocatalysis on Water Treatment and Fish Performance in Saline Recirculating Aquaculture System

    Science.gov (United States)

    Ye, Zhangying; Wang, Shuo; Gao, Weishan; Li, Haijun; Pei, Luowei; Shen, Mingwei; Zhu, Songming

    2017-03-01

    A new physico-chemical process for TAN (total ammonia nitrogen) removal and disinfection is introduced in saline recirculating aquaculture system (RAS), in which the biofilter is replaced with an integrated electrolysis cell and an activated carbon filter. The electrolysis cell which is based on micro current electrolysis combined with UV-light was self-designed. After the fundamental research, a small pilot scale RAS was operated for 30 days to verify the technical feasibility. The system was stocked by 42 GIFT tilapia (Oreochromis niloticus) fish with the rearing density of 13 kg/m3. During the experiments, the TAN concentration remained below 1.0 mg/L. The nitrite concentration was lower than 0.2 mg/L and the nitrate concentration had increased continuously to 12.79 mg/L at the end. Furthermore, the concentration of residual chlorine in culture ponds remained below 0.3 mg/L, ORP maintained slight fluctuations in the range of 190~240 mV, and pH of the water showed the downtrend. Tilapia weight increased constantly to 339.3 ± 10 g. For disinfection, the active chlorine generated by electrochemical treatment caused Escherichia coli inactivation. Enzyme activity assay indicated that the activity of glutamate dehydrogenase, carbonic anhydrase and glutamic pyruvic transaminase increased within the normal range. The preliminary feasibility was verified by using this physico-chemical technology in the RAS.

  2. Blood to skin recirculation of CD4+ memory T cells associates with cutaneous and systemic manifestations of psoriatic disease.

    Science.gov (United States)

    Diani, Marco; Galasso, Marco; Cozzi, Chiara; Sgambelluri, Francesco; Altomare, Andrea; Cigni, Clara; Frigerio, Elena; Drago, Lorenzo; Volinia, Stefano; Granucci, Francesca; Altomare, Gianfranco; Reali, Eva

    2017-07-01

    Blood to skin recirculation could play a role in the pathogenesis of psoriasis. To investigate this possibility we dissected the phenotype of circulating T cells in psoriasis patients, calculated the correlation the clinical parameters of the disease and performed a parallel bioinformatics analysis of gene expression data in psoriatic skin. We found that circulating CCR6 + CD4 + T EM and T EFF cells significantly correlated with systemic inflammation. Conversely, the percentage of CXCR3 + CD4 + T EM cells negatively correlated with the severity of the cutaneous disease. Importantly CLA + CD4 + T CM cells expressing CCR6 + or CCR4 + CXCR3 + negatively correlated with psoriasis severity suggesting recruitment to the skin compartment. This assumption was reinforced by gene expression data showing marked increase of CCR7 and CLA-encoding gene SELPLG expression in psoriatic skin and strong association of their expression. The data enlightens a role for CD4 + T cells trafficking between blood and skin in cutaneous and systemic manifestations of psoriasis. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Effect of a solar Fered-Fenton system using a recirculation reactor on biologically treated landfill leachate.

    Science.gov (United States)

    Ye, Zhihong; Zhang, Hui; Yang, Lin; Wu, Luxue; Qian, Yue; Geng, Jinyao; Chen, Mengmeng

    2016-12-05

    The effects of electrochemical oxidation (EO), Fered-Fenton and solar Fered-Fenton processes using a recirculation flow system containing an electrochemical cell and a solar photo-reactor on biochemically treated landfill leachate were investigated. The most successful method was solar Fered-Fenton which achieved 66.5% COD removal after 120min treatment utilizing the optimum operating conditions of 47mM H2O2, 0.29mM Fe(2+), pH0 of 3.0 and a current density of 60mA/cm(2). The generation of hydroxyl radicals (OH) are mainly from Fered-Fenton process, which is enhanced by the introduction of renewable solar energy. Moreover, Fe(2+)/chlorine and UV/chlorine processes taking place in this system also result in additional production of OH due to the relatively high concentration of chloride ions contained in the leachate. The energy consumption was 74.5kWh/kg COD and the current efficiency was 36.4% for 2h treatment. In addition, the molecular weight (MW) distribution analysis and PARAFAC analysis of excitation emission matrix (EEM) fluorescence spectroscopy for different leachate samples indicated that the organics in the leachate were significantly degraded into either small molecular weight species or inorganics. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Synergistic Effects of Micro-electrolysis-Photocatalysis on Water Treatment and Fish Performance in Saline Recirculating Aquaculture System.

    Science.gov (United States)

    Ye, Zhangying; Wang, Shuo; Gao, Weishan; Li, Haijun; Pei, Luowei; Shen, Mingwei; Zhu, Songming

    2017-03-27

    A new physico-chemical process for TAN (total ammonia nitrogen) removal and disinfection is introduced in saline recirculating aquaculture system (RAS), in which the biofilter is replaced with an integrated electrolysis cell and an activated carbon filter. The electrolysis cell which is based on micro current electrolysis combined with UV-light was self-designed. After the fundamental research, a small pilot scale RAS was operated for 30 days to verify the technical feasibility. The system was stocked by 42 GIFT tilapia (Oreochromis niloticus) fish with the rearing density of 13 kg/m 3 . During the experiments, the TAN concentration remained below 1.0 mg/L. The nitrite concentration was lower than 0.2 mg/L and the nitrate concentration had increased continuously to 12.79 mg/L at the end. Furthermore, the concentration of residual chlorine in culture ponds remained below 0.3 mg/L, ORP maintained slight fluctuations in the range of 190~240 mV, and pH of the water showed the downtrend. Tilapia weight increased constantly to 339.3 ± 10 g. For disinfection, the active chlorine generated by electrochemical treatment caused Escherichia coli inactivation. Enzyme activity assay indicated that the activity of glutamate dehydrogenase, carbonic anhydrase and glutamic pyruvic transaminase increased within the normal range. The preliminary feasibility was verified by using this physico-chemical technology in the RAS.

  5. Corrosion inhibition measures in primary cooling water system during refurbishment of Cirus, re-commissioning and subsequent operation

    International Nuclear Information System (INIS)

    Rai, K.K.; Ramesh, N.; Sharma, R.C.

    2008-01-01

    Cirus is a 40 MWth, heavy water moderated, demineralized light water cooled, natural uranium fuelled research reactor. Reactor was commissioned in year 1960 and operated satisfactorily till 1990. After that availability factor started decreasing mainly due to equipment outage exhibiting signs of ageing. Based upon systematic ageing studies and assessment of condition of systems, structures and components, a refurbishment plan including safety upgrades was drawn up. Reactor was shut down in October 1997 for execution of jobs. After completion of refurbishment jobs reactor was started back in October 2002 and power operation was achieved in 2003. Primary cooling water (PCW) system consists of re-circulating pumps, heat exchangers, expansion tank, piping, valves, emergency storage reservoir (Ball Tank) and other components. Normally the fission heat from fuel is removed by re-circulating coolant in closed loop and transferred to seawater via heat exchangers. In case of outage of pumps, shut down cooling is provided by flow of water from Ball Tank under gravity to the underground dump tanks. The dissolved oxygen is maintained below 2 ppm and pH is maintained neutral to minimize corrosion of fuel cladding (Aluminum). This paper highlights the experience gained during segmentation of primary cooling water pipelines for pressure testing, measures taken to corrosion inhibition of primary cooling water lines to permit execution of refurbishment jobs, inspections and actions taken to repair/replace the corroded PCW pipe line segments, observations regarding corrosion related failures, re-commissioning of the system after refurbishment, assessment for safe reactor operation and experience during power operation. (author)

  6. Modelling and analysis of a desiccant cooling system using the regenerative indirect evaporative cooling process

    DEFF Research Database (Denmark)

    Bellemo, Lorenzo; Elmegaard, Brian; Reinholdt, Lars O.

    2013-01-01

    This paper focuses on the numerical modeling and analysis of a Desiccant Cooling (DEC) system with regenerative indirect evaporative cooling, termed Desiccant Dewpoint Cooling (DDC) system. The DDC system includes a Desiccant Wheel (DW), Dew Point Coolers (DPCs), a heat recovery unit and a heat...... in different climates: temperate in Copenhagen and Mediterranean in Venice. Cheap and clean heat sources (e.g. solar energy) strongly increase the attractiveness of the DDC system. For the Mediterranean climate the DDC system represents a convenient alternative to chiller-based systems in terms of energy costs...... and CO2 emissions. The electricity consumption for auxiliaries in the DDC system is higher than in the chiller-based systems. The number of commercial-size DPC units required to cover the cooling load during the whole period is high: 8 in Copenhagen and 12 in Venice....

  7. Spacesuit Water Membrane Evaporator; An Enhanced Evaporative Cooling System for the Advanced Extravehicular Mobility Unit Portable Life Support System

    Science.gov (United States)

    Bue, Grant C.; Makinen, Janice V.; Miller, Sean; Campbell, Colin; Lynch, Bill; Vogel, Matt; Craft, Jesse; Wilkes, Robert; Kuehnel, Eric

    2014-01-01

    Development of the Advanced Extravehicular Mobility Unit (AEMU) portable life support subsystem (PLSS) is currently under way at NASA Johnson Space Center. The AEMU PLSS features a new evaporative cooling system, the Generation 4 Spacesuit Water Membrane Evaporator (Gen4 SWME). The SWME offers several advantages when compared with prior crewmember cooling technologies, including the ability to reject heat at increased atmospheric pressures, reduced loop infrastructure, and higher tolerance to fouling. Like its predecessors, Gen4 SWME provides nominal crew member and electronics cooling by flowing water through porous hollow fibers. Water vapor escapes through the hollow fiber pores, thereby cooling the liquid water that remains inside of the fibers. This cooled water is then recirculated to remove heat from the crew member and PLSS electronics. Test results from the backup cooling system which is based on a similar design and the subject of a companion paper, suggested that further volume reductions could be achieved through fiber density optimization. Testing was performed with four fiber bundle configurations ranging from 35,850 fibers to 41,180 fibers. The optimal configuration reduced the Gen4 SWME envelope volume by 15% from that of Gen3 while dramatically increasing the performance margin of the system. A rectangular block design was chosen over the Gen3 cylindrical design, for packaging configurations within the AEMU PLSS envelope. Several important innovations were made in the redesign of the backpressure valve which is used to control evaporation. A twin-port pivot concept was selected from among three low profile valve designs for superior robustness, control and packaging. The backpressure valve motor, the thermal control valve, delta pressure sensors and temperature sensors were incorporated into the manifold endcaps, also for packaging considerations. Flight-like materials including a titanium housing were used for all components. Performance testing

  8. SNS Resonance Control Cooling Systems and Quadrupole Magnet Cooling Systems DIW Chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Magda, Karoly [ORNL

    2018-01-01

    This report focuses on control of the water chemistry for the Spallation Neutron Source (SNS) Resonance Control Cooling System (RCCS)/Quadrupole Magnet Cooling System (QMCS) deionized water (DIW) cooling loops. Data collected from spring 2013 through spring 2016 are discussed, and an operations regime is recommended.It was found that the RCCS operates with an average pH of 7.24 for all lines (from 7.0 to 7.5, slightly alkaline), the average low dissolved oxygen is in the area of < 36 ppb, and the main loop average resistivity of is > 14 MΩ-cm. The QMCS was found to be operating in a similar regime, with a slightly alkaline pH of 7.5 , low dissolved oxygen in the area of < 45 ppb, and main loop resistivity of 10 to 15 MΩ-cm. During data reading, operational corrections were done on the polishing loops to improve the water chemistry regime. Therefore some trends changed over time.It is recommended that the cooling loops operate in a regime in which the water has a resistivity that is as high as achievable, a dissolved oxygen concentration that is as low as achievable, and a neutral or slightly alkaline pH.

  9. GROWTH ENHANCEMENT, SURVIVAL AND DECREASE OF ECTOPARASITIC INFECTIONS IN MASCULINIZED NILE TILAPIA FRY IN A RECIRCULATING AQUACULTURE SYSTEM

    Directory of Open Access Journals (Sweden)

    Isabel Jiménez García

    2012-11-01

    Full Text Available Under lab conditions, tilapia fry at culture densities of 8 fish/L-1 can reach a body weight of 0.5 to 1.0 g after the masculinization phase. In commercial hatcheries, the stocking density is four to six times higher, and consequently the occurrence of ectoparasitic infections also rises. The aim of this study was to examine the growth and survival of masculinized Nile tilapia (Oreochromis niloticus fry in a recirculating aquaculture system (RAS. The fry, which were naturally parasitized by protozoan of the genera Trichodina, Ambiphrya and Chilodonella, weighed 0.013 ± 0.003 g and were reared in replicated tanks (N = 3 during 32 days at density of 18 fish/L-1 in the RAS to maintain good water quality, which was achieved especially during the first 22 days of fish rearing. The infection parameters and growth were monitored twice a week. The final fish weight was 1.17 ± 0. 6 g and survival 99.5%. The most frequent parasites were Trichodina and Gyrodactylus cichlidarum (Monogenea. Although nitrogen compounds increased significantly over the last 10 days of fry rearing, final growth and survival were higher than those reported, additionally, the ectoparasitic infections were relatively low.

  10. Measurement of in-core and recirculation system response to hydrogen water chemistry at Nine Mile Point 1

    International Nuclear Information System (INIS)

    Head, R.A.; Indig, M.E.; Andresen, P.L.

    1991-03-01

    The value of hydrogen water chemistry (HWC) as a mitigation technique for out-of-core piping systems susceptible to intergranular stress corrosion cracking (IGSCC) is well established. However, certain reactor internal components exposed to high levels of radiation are susceptible to a cracking mechanism referred to as irradiation assisted stress corrosion cracking (IASCC). Some of the components potentially affected by IASCC include the top guide, SRM/IRM housings, the core shroud, and control blades. Fortunately, laboratory data indicate that IASCC can be controlled by altering the coolant environment. Hot cell tests performed at GE's Vallecitos Nuclear Center (VNC) on highly irradiated material produced a fracture surface with 99% IGSCC under normal BWR water chemistry. However, under HWC conditions, only ductile failure occurred. With this background, a program was established to determine the chemistry and oxidizing potential of the core bypass coolant at Nine Mile Point-1 (NMP-1) under normal and HWC conditions. The objective of the program was to assess whether HWC could sufficiently modify the core bypass environment to mitigate IASCC. Results showed that with the addition of hydrogen to the feedwater, core bypass dissolved oxygen decreased very rapidly, compared to the recirculation water, indicating very efficient recombination of hydrogen and oxygen in the non-boiling core bypass region. Since low concentrations of dissolved oxygen have been shown to eliminate IASCC, these results are encouraging. 8 figs., 1 tab

  11. Comparison of aerobically-treated and untreated crop residue as a source of recycled nutrients in a recirculating hydroponic system

    Science.gov (United States)

    Mackowiak, C. L.; Garland, J. L.; Strayer, R. F.; Finger, B. W.; Wheeler, R. M.

    1996-01-01

    This study compared the growth of potato plants on nutrients recycled from inedible potato biomass. Plants were grown for 105 days in recirculating, thin-film hydroponic systems containing four separate nutrient solution treatments: (1) modified half-strength Hoagland's (control), 2) liquid effluent from a bioreactor containing inedible potato biomass, 3) filtered (0.2 micrometer) effluent, and 4) the water soluble fraction of inedible potato biomass (leachate). Approximately 50% of the total nutrient requirement in treatments 2-4 were provided (recycled) from the potato biomass. Leachate had an inhibitory effect on leaf conductance, photosynthetic rate, and growth (50% reduction in plant height and 60% reduction in tuber yield). Plants grown on bioreactor effluent (filtered or unfiltered) were similar to the control plants. These results indicated that rapidly degraded, water soluble organic material contained in the inedible biomass, i.e., material in leachate, brought about phytotoxicity in the hydroponic culture of potato. Recalcitrant, water soluble organic material accumulated in all nutrient recycling treatments (650% increase after 105 days), but no increase in rhizosphere microbial numbers was observed.

  12. Natural circulating passive cooling system for nuclear reactor containment structure

    Science.gov (United States)

    Gou, Perng-Fei; Wade, Gentry E.

    1990-01-01

    A passive cooling system for the contaminant structure of a nuclear reactor plant providing protection against overpressure within the containment attributable to inadvertent leakage or rupture of the system components. The cooling system utilizes natural convection for transferring heat imbalances and enables the discharge of irradiation free thermal energy to the atmosphere for heat disposal from the system.

  13. Passive cooling system for nuclear reactor containment structure

    Science.gov (United States)

    Gou, Perng-Fei; Wade, Gentry E.

    1989-01-01

    A passive cooling system for the contaminant structure of a nuclear reactor plant providing protection against overpressure within the containment attributable to inadvertent leakage or rupture of the system components. The cooling system utilizes natural convection for transferring heat imbalances and enables the discharge of irradiation free thermal energy to the atmosphere for heat disposal from the system.

  14. PEP cooling water systems and underground piped utilities design criteria report

    International Nuclear Information System (INIS)

    Hall, F.; Robbins, D.

    1975-10-01

    This paper discusses the cooling systems required by the PEP Storage Ring. Particular topics discussed are: Cooling tower systems, RF cavity and vacuum chamber LCW cooling systems, klystron and ring magnet LLW cooling systems, Injection magnet LCW Cooling Systems; PEP interaction area detector LCW Cooling Systems; and underground piped utilities. 1 ref., 20 figs

  15. Cooling systems research at Argonne National Laboratory

    International Nuclear Information System (INIS)

    Spigarelli, S.A.

    1977-01-01

    Studies of the thermal plumes resulting from discharges from once-through cooling systems of electric generating stations are reviewed. The collection of large amounts of water temperature data for definition of the three-dimensional structure of a thermal plume, of current data, and related ambient data for model evaluation purposes required the development of an integrated data collection system. The Argonne system employs measurements of water temperature over the water column from a moving small boat. Temperatures are measured with thermistors attached to a rigid strut for surface plumes and to a flexible, faired cable for submerged plumes. Water temperatures and boat location, determined by a microwave ranging system, are recorded on magnetic tape while the boat is underway and prove a quasi-synoptic map of plume temperatures. Automated data handling and processing procedures provide for the production of isotherm maps of the plume at several elevations and in cross section. Mathematical model evaluation for surface discharges of waste heat included the consideration of over 40 different models and detailed evaluation of 11 models. Most models were run on Argonne's computers, and all models were evaluated in terms of their limitations and capabilities as well as their predictive performance against prototype data. Measurements were made of thermal plumes at the discharges of nuclear power plants located on the shores of Lake Michigan

  16. Simulation of an adsorption solar cooling system

    International Nuclear Information System (INIS)

    Hassan, H.Z.; Mohamad, A.A.; Bennacer, R.

    2011-01-01

    A more realistic theoretical simulation model for a tubular solar adsorption refrigerating system using activated carbon-methanol (AC/M) pair has been introduced. The mathematical model represents the heat and mass transfer inside the adsorption bed, the condenser, and the evaporator. The simulation technique takes into account the variations of ambient temperature and solar radiation along the day. Furthermore, the local pressure, and local thermal conductivity variations in space and time inside the tubular reactor are investigated as well. A C++ computer program is written to solve the proposed numerical model using the finite difference method. The developed program covers the operations of all the system components along the cycle time. The performance of the tubular reactor, the condenser, and the evaporator has been discussed. Time allocation chart and switching operations for the solar refrigeration system processes are illustrated as well. The case studied has a 1 m 2 surface area solar flat plate collector integrated with a 20 stainless steel tubes containing the AC/M pair and each tube has a 5 cm outer diameter. In addition, the condenser pressure is set to 54.2 kpa. It has been found that, the solar coefficient of performance and the specific cooling power of the system are 0.211 and 2.326 respectively. In addition, the pressure distribution inside the adsorption bed has been found nearly uniform and varying only with time. Furthermore, the AC/M thermal conductivity is shown to be constant in both space and time.

  17. Four years experience with filtration systems in commercial nurseries for eliminating Phytophthora species from recirculation water

    Science.gov (United States)

    T. Ufer; M. Posner; H.-P. Wessels; S. Wagner; K. Kaminski; T. Brand; Werres S.

    2008-01-01

    In a four year project, three different filtration systems were tested under commercial nursery conditions to eliminate Phytophthora spp. from irrigation water. Five nurseries were involved in the project. Slow sand filtration systems were tested in three nurseries. In the fourth nursery, a filtration system with lava grains (Shieer® Bio filtration)...

  18. Nitrogen and Phosphorus Removal in the Recirculating Aquaculture System with Water Treatment Tank containing Baked Clay Beads and Chinese Cabbage

    Directory of Open Access Journals (Sweden)

    Aeknarin Thanakitpairin

    2014-01-01

    Full Text Available This research aims to describe the nitrogen and phosphorus removal in Recirculating Aquaculture System (RAS by crop plants biomass production. The 3 experiment systems consisted of 1 treatment (fish tank + baked clay beads + Chinese cabbage and 2 controls as control-1 (fish tank only and control-2 (fish tank + baked clay beads, were performed. With all experimental RAS, Nile tilapia (Oreochromis niloticus was cultured at 2 kg/m3 density. The baked clay beads (8-16 mm in diameter were filled as a layer of 10 cm in the water treatment tank of control-2. While in the treatment tank, Chinese cabbage (Brassica pekinensis was planted at 334 plants/m2 in baked clay beads layer. During 35 days of experiment, the average fish wet-weight in control-1, control-2 and treatment systems increased from 16.31±1.49, 15.18±1.28 and 11.31±1.49 g to 29.43±7.06, 28.65±3.12 and 27.20±6.56 g, respectively. It was found that the growth rate of 0.45±0.15 g-wet weight/day in a treatment tank was higher than in those 2 controls, which were rather similar at 0.37±0.16 and 0.38±0.05 g-wet weight/day, respectively. The fish survival rate of all experimental units was 100%. The average Chinese cabbage wet-weight in treatment system increased from 0.15±0.02 g to 1.00±0.38 g. For water quality, all parameters were within the acceptable range for aquaculture. The assimilation inorganic nitrogen in a treatment tank showed a slower rate and lower nitrite accumulation relative to those in control tanks. The nitrogen and phosphorus balance analysis illustrated that most of the nitrogen and phosphorus input in all systems was from feed (82-87% and 21-87% while at the final day of experiments, nitrogen and phosphorus in tilapia culture revealed at 15-19% and 4-13%. The accumulation of nitrogen and phosphorus in the water, up to 56% and 70%, was found in control-1 while water in the tank with baked clay beads had substantial lower nitrogen and phosphorus concentration. The

  19. GOTHIC Simulation of Passive Containment Cooling System

    International Nuclear Information System (INIS)

    Ha, Huiun; Kim, Hangon

    2013-01-01

    The performance of this system depends on the condensation of steam moving downward inside externally cooled vertical tubes. AES-2006: During a DBA, heat is removed by internally cooled vertical tubes, which are located in containment. We are currently developing the conceptual design of Innovative PWR, which is will be equipped with various passive safety features, including PCCS. We have plan to use internal heat exchanger (HX) type PCCS with concrete containment. In this case, the elevation of HXs is important to ensure the heat removal during accidents. In general, steam is lighter than air mixture in containment. So, steam may be collected at the upper side of containment. It means that higher elevation of HXs, larger heat removal efficiency of those. So, the aim of the present paper is to give preliminary study on variation of heat removal performance according to elevation of HXs. With reference to the design specification of the current reactors including APR+, we had determined conceptual design of PCCS. Using it, we developed a GOTHIC model of the APR1400 containment was adopted PCCS. This calculation model is described herein and representative results of calculation are presented. APR 1400 GOTHIC model was developed for PCCS performance calculation and sensitivity test according to installation elevation of PCCXs. Calculation results confirm that PCCS is working properly. It is found that the difference due to the installation elevation of PCCXs is insignificant at this preliminary analysis, however, further studies should be performed to confirm final performance of PCCS according to the installation elevation. These insights are important for developing the PCCS of Innovative PWR

  20. GOTHIC Simulation of Passive Containment Cooling System

    Energy Technology Data Exchange (ETDEWEB)

    Ha, Huiun; Kim, Hangon [Korea Hydro and Nuclear Power Co. Ltd., Daejeon (Korea, Republic of)

    2013-05-15

    The performance of this system depends on the condensation of steam moving downward inside externally cooled vertical tubes. AES-2006: During a DBA, heat is removed by internally cooled vertical tubes, which are located in containment. We are currently developing the conceptual design of Innovative PWR, which is will be equipped with various passive safety features, including PCCS. We have plan to use internal heat exchanger (HX) type PCCS with concrete containment. In this case, the elevation of HXs is important to ensure the heat removal during accidents. In general, steam is lighter than air mixture in containment. So, steam may be collected at the upper side of containment. It means that higher elevation of HXs, larger heat removal efficiency of those. So, the aim of the present paper is to give preliminary study on variation of heat removal performance according to elevation of HXs. With reference to the design specification of the current reactors including APR+, we had determined conceptual design of PCCS. Using it, we developed a GOTHIC model of the APR1400 containment was adopted PCCS. This calculation model is described herein and representative results of calculation are presented. APR 1400 GOTHIC model was developed for PCCS performance calculation and sensitivity test according to installation elevation of PCCXs. Calculation results confirm that PCCS is working properly. It is found that the difference due to the installation elevation of PCCXs is insignificant at this preliminary analysis, however, further studies should be performed to confirm final performance of PCCS according to the installation elevation. These insights are important for developing the PCCS of Innovative PWR.

  1. Load calculations of radiant cooling systems for sizing the plant

    DEFF Research Database (Denmark)

    Bourdakis, Eleftherios; Kazanci, Ongun Berk; Olesen, Bjarne W.

    2015-01-01

    The aim of this study was, by using a building simulation software, to prove that a radiant cooling system should not be sized based on the maximum cooling load but at a lower value. For that reason six radiant cooling models were simulated with two control principles using 100%, 70% and 50......% of the maximum cooling load. It was concluded that all tested systems were able to provide an acceptable thermal environment even when the 50% of the maximum cooling load was used. From all the simulated systems the one that performed the best under both control principles was the ESCS ceiling system. Finally...... it was proved that ventilation systems should be sized based on the maximum cooling load....

  2. Study of Water Quality of Recirculated Water in Aquaponic Systems: Study of speciation of selected metals and characterization of the properties of natural organic matter

    OpenAIRE

    Gjesteland, Ingrid

    2013-01-01

    This thesis describes an extensive study on how water quality changes over time in a small scale recirculating system where waste water from smolt production was used to grow lettuce for commercial use. The treatment effect of lettuce on different solutions was tested and corresponding lettuce yield was evaluated. In order to enhance the treatment effect a rock wool filter was used on certain solutions. Important water quality parameters were measured every day, and the element concentration ...

  3. Integrated cooling system for the Mirror Fusion Test Facility

    International Nuclear Information System (INIS)

    Johnson, B.; Chang, Y.

    1979-01-01

    The MFTF components that require water cooling include the neutral beam dumps, ion dumps, plasma dumps, baffle plates, magnet liners, gas boxes, streaming guns, and the neutral beam injectors. A total heat load of nearly 500 MW for 0.5 s dissipates over 4-min intervals. A steady-flow, closed-loop system is utilized. The design of the cooling system assumes that all components require cooling simultaneously. The cooling system contains process instrumentation for loop control. Alarms and safety interlocks are incorporated for the safe operation of the system

  4. End-of-pipe single-sludge denitrification in pilot-scale recirculating aquaculture systems

    DEFF Research Database (Denmark)

    Suhr, Karin Isabel; Pedersen, Lars-Flemming; Nielsen, J.L.

    2014-01-01

    A step toward environmental sustainability of recirculat aquaculture systems (RAS) is implementation ofsingle-sludge denitrification, a process eliminating nitrate from the aqueous environment while reduc-ing the organic matter discharge simultaneously. Two 1700 L pilot-scale RAS systems each...

  5. Efficient and economical way of operating a recirculation aquaculture system in an aquaponics farm

    NARCIS (Netherlands)

    Karimanzira, Divas; Keesman, Karel; Kloas, Werner; Baganz, Daniela; Rauschenbach, Thomas

    2017-01-01

    In this article, optimal control methods based on a metabolite-constrained fish growth model are applied to the operation of fish production in an aquaponic system. The system is formulated for the twin objective of fish growth and plant fertilization to maximize the benefits by optimal and

  6. Simulation and tests to individual and coupled models of the reactor vessel simulator and the recirculation system for the SUN-RAH

    International Nuclear Information System (INIS)

    Sanchez S, R.A.

    2004-01-01

    The present project, is continuation of the project presented in the congress SNM-2003. In this new phase of the project, they were carried out adaptive changes to the modeling and implementation of the module of the full superior of the core of the reactor, they were carried out those modeling of the generation of heat as well as of the energy transfer in the one fuel. These models present the main characteristics of the vessel of the one reactor and of the recirculation system, defined by the main phenomena that they intervene in the physical processes, in the previous version the simulation in real time it required of an extremely quick computer and without executing collateral processes. The tests are presented carried out to the different models belonging to the Simulator of the Reactor Vessel and the Recirculation system for the SUN-RAH (University Simulator of Nucleo electric with Boiling Water Reactor), as well as the results hurtled by this tests. In each section the executions of the tests and the corresponding analyses of results are shown for each pattern. Besides the above mentioned, the advantages presented by the Simulator of the reactor vessel and the recirculation system are pointed. (Author)

  7. Method of injecting cooling water in emergency core cooling system (ECCS) of PWR type reactor

    International Nuclear Information System (INIS)

    Sobajima, Makoto; Adachi, Michihiro; Tasaka, Kanji; Suzuki, Mitsuhiro.

    1979-01-01

    Purpose: To provide a cooling water injection method in an ECCS, which can perform effective cooling of the reactor core. Method: In a method of injecting cooling water in an ECCS as a countermeasure against a rupture accident of a pwr type reactor, cooling water in the first pressure storage injection system is injected into the upper plenum of the reactor pressure vessel at a set pressure of from 50 to 90 atg. and a set temperature of from 80 to 200 0 C, cooling water in the second pressure storage injection system is injected into the lower plenum of the reactor pressure vessel at a pressure of from 25 to 60 atg. which is lower than the set pressure and a temperature less than 60 0 C, and further in combination with these procedures, cooling water of less than 60 0 C is injected into a high-temperature side piping, in the high-pressure injection system of upstroke of 100 atg. by means of a pump and the low-pressure injection system of upstroke of 20 atg. also by means of a pump, thereby cooling the reactor core. (Aizawa, K.)

  8. Electric drive systems including smoothing capacitor cooling devices and systems

    Energy Technology Data Exchange (ETDEWEB)

    Dede, Ercan Mehmet; Zhou, Feng

    2017-02-28

    An electric drive system includes a smoothing capacitor including at least one terminal, a bus bar electrically coupled to the at least one terminal, a thermoelectric device including a first side and a second side positioned opposite the first side, where the first side is thermally coupled to at least one of the at least one terminal and the bus bar, and a cooling element thermally coupled to the second side of the thermoelectric device, where the cooling element dissipates heat from the thermoelectric device.

  9. The Role of Absorption Cooling for Reaching Sustainable Energy Systems

    Energy Technology Data Exchange (ETDEWEB)

    Lindmark, Susanne

    2005-07-01

    This thesis focuses on the role and potential of absorption cooling in future energy systems. Two types of energy systems are investigated: a district energy system based on waste incineration and a distributed energy system with natural gas as fuel. In both cases, low temperature waste heat is used as driving energy for the absorption cooling. The main focus is to evaluate the absorption technology in an environmental perspective, in terms of reduced CO{sub 2} emissions. Economic evaluations are also performed. The reduced electricity when using absorption cooling instead of compression cooling is quantified and expressed as an increased net electrical yield. The results show that absorption cooling is an environmentally friendly way to produce cooling as it reduces the use of electrically driven cooling in the energy system and therefore also reduces global CO{sub 2} emissions. In the small-scale trigeneration system the electricity use is lowered with 84 % as compared to cooling production with compression chillers only. The CO{sub 2} emissions can be lowered to 45 CO{sub 2}/MWh{sub c} by using recoverable waste heat as driving heat for absorption chillers. However, the most cost effective cooling solution in a district energy system is a combination between absorption and compression cooling technologies according to the study. Absorption chillers have the potential to be suitable bottoming cycles for power production in distributed systems. Net electrical yields over 55 % may be reached in some cases with gas motors and absorption chillers. This small-scale system for cogeneration of power and cooling shows electrical efficiencies comparable to large-scale power plants and may contribute to reducing peak electricity demand associated with the cooling demand.

  10. Cryogenic system with the sub-cooled liquid nitrogen for cooling HTS power cable

    Energy Technology Data Exchange (ETDEWEB)

    Fan, Y.F. [Chinese Academy of Sciences, Beijing (China). Technical Institute of Physics and Chemistry; Graduate School of Chinese Academy of Sciences, Beijing (China); Gong, L.H.; Xu, X.D.; Li, L.F.; Zhang, L. [Chinese Academy of Sciences, Beijing (China). Technical Institute of Physics and Chemistry; Xiao, L.Y. [Chinese Academy of Sciences, Beijing (China). Institute of Electrical Engineering

    2005-04-01

    A 10 m long, three-phase AC high-temperature superconducting (HTS) power cable had been fabricated and tested in China August 2003. The sub-cooled liquid nitrogen (LN{sub 2}) was used to cool the HTS cable. The sub-cooled LN{sub 2} circulation was built by means of a centrifugal pump through a heat exchanger in the sub-cooler, the three-phase HTS cable cryostats and a LN{sub 2} gas-liquid separator. The LN{sub 2} was cooled down to 65 K by means of decompressing, and the maximum cooling capacity was about 3.3 kW and the amount of consumed LN{sub 2} was about 72 L/h at 1500 A. Cryogenic system design, test and some experimental results would be presented in this paper. (author)

  11. Development of a water recirculating system for bullfrog production: technological innovation for small farmers

    Directory of Open Access Journals (Sweden)

    Sílvia Conceição Reis Pereira Mello

    2016-02-01

    Full Text Available ABSTRACT Despite the technological progress in frog farming, issues related to the environment, biosafety, and the use of technologies that minimise environmental impacts are frequently neglected by farmers. With the goal of developing a low-cost technology for reuse and preservation of water quality, an anaerobic filtering system combined with an aerobic filtering system was implemented in the grow-out sector in the Frog Culture Research Unit at Fundação Instituto de Pesca do Estado do Rio de Janeiro (FIPERJ. The filtering system received the effluent from six pens of frogs that were populated with 362 frogs in different development phases. The efficiency of the filtering system was evaluated by an analysis of the water before and after passing through the filters. In addition to the standards of water quality, the animals' performance was also observed through monitoring rates of survival, weight gain and feed conversion ratio. The results showed the effectiveness of the filtering system by removing organic matter, on average 87%. The values of total ammonia and non-ionisable reached 1.04 and 0.004 mg/L, respectively. Also, frogs subjected to the system presented satisfactory rates of weight gain and a high survival rate (97%.

  12. ELECTRONIC CIRCUIT BOARDS NON-UNIFORM COOLING SYSTEM MODEL

    Directory of Open Access Journals (Sweden)

    D. V. Yevdulov

    2016-01-01

    Full Text Available Abstract. The paper considers a mathematical model of non-uniform cooling of electronic circuit boards. The block diagram of the system implementing this approach, the method of calculation of the electronic board temperature field, as well as the principle of its thermal performance optimizing are presented. In the considered scheme the main heat elimination from electronic board is produced by the radiator system, and additional cooling of the most temperature-sensitive components is produced by thermoelectric batteries. Are given the two-dimensional temperature fields of the electronic board during its uniform and non-uniform cooling, is carried out their comparison. As follows from the calculations results, when using a uniform overall cooling of electronic unit there is a waste of energy for the cooling 0f electronic board parts which temperature is within acceptable temperature range without the cooling system. This approach leads to the increase in the cooling capacity of used thermoelectric batteries in comparison with the desired values. This largely reduces the efficiency of heat elimination system. The use for electronic boards cooling of non-uniform local heat elimination removes this disadvantage. The obtained dependences show that in this case, the energy required to create a given temperature is smaller than when using a common uniform cooling. In this approach the temperature field of the electronic board is more uniform and the cooling is more efficient. 

  13. Biofouling problems in freshwater cooling systems

    International Nuclear Information System (INIS)

    Rao, T.S.

    2007-01-01

    In aqueous environments, microorganisms (bacteria, algae, fungi etc.,) are attracted towards surfaces, which they readily colonise resulting in the formation of biofilms. The implications of biofouling are energy losses due to increased fluid frictional resistance and increased heat transfer resistance. The temperatures prevalent inside the condenser system provide a favorable environment for the rapid growth of microorganisms. This results in thick slime deposit, which is responsible for heat transfer losses, thereby enhancing aggregation of deposits on the material surface and induces localised corrosion. There have been instances of increased capital costs due to premature replacement of equipment caused by severe under deposit corrosion due to biofouling. Moreover, fouling of service water systems of nuclear power plants is of concern, because it reduces the heat transfer capacity during an emergency or an accident. The growth of microbial films (slimes) a few tens of microns thick, in a condenser tube is sufficient to induce microbiologically influenced corrosion and cause irreparable damage to the condenser tubes and other structural materials. The down time costs to power plant due to condenser fouling and corrosion are quite large. This paper presents the author's experience in biofouling and corrosion problems in various power plants cooled by freshwater. (author)

  14. Resistance and resilience of small-scale recirculating aquaculture systems (RAS) with or without algae to pH perturbation

    Science.gov (United States)

    Giatsis, Christos; Md Yusoff, Fatimah; Verreth, Johan; Verdegem, Marc

    2018-01-01

    The experimental set-up of this study mimicked recirculating aquaculture systems (RAS) where water quality parameters such as dissolved oxygen, pH, temperature, and turbidity were controlled and wastes produced by fish and feeding were converted to inorganic forms. A key process in the RAS was the conversion of ammonia to nitrite and nitrite to nitrate through nitrification. It was hypothesized that algae inclusion in RAS would improve the ammonia removal from the water; thereby improving RAS water quality and stability. To test this hypothesis, the stability of the microbiota community composition in a freshwater RAS with (RAS+A) or without algae (RAS-A) was challenged by introducing an acute pH drop (from pH 7 to 4 during three hours) to the system. Stigeoclonium nanum, a periphytic freshwater microalga was used in this study. No significant effect of the algae presence was found on the resistance to the acute pH drop on ammonia conversion to nitrite and nitrite conversion to nitrate. Also the resilience of the ammonia conversion to the pH drop disruption was not affected by the addition of algae. This could be due to the low biomass of algae achieved in the RAS. However, with regard to the conversion step of nitrite to nitrate, RAS+A was significantly more resilient than RAS-A. In terms of overall bacterial communities, the composition and predictive function of the bacterial communities was significantly different between RAS+A and RAS-A. PMID:29659617

  15. Systems design of direct-cycle supercritical-water-cooled fast reactors

    International Nuclear Information System (INIS)

    Oka, Yoshiaki; Koshizuka, Seiichi; Jevremovic, Tatjana; Okano, Yashushi

    1995-01-01

    The system design of a direct-cycle supercritical-water-cooled fast reactor is presented. The supercritical water does not exhibit a change of phase. the recirculation system, steam separator, and dryer of a boiling water reactor (BWR) are unnecessary. Roughly speaking, the reactor pressure vessel and control rods are similar to those of a pressurized water reactor, the containment and emergency core cooling system are similar to a BWR, and the balance of plant is similar to a supercritical-pressure fossil-fired power plant (FPP). the electric power of the fast converter is 1,508 MW(electric). The number of coolant loops is only two because of the high coolant enthalpy. Containment volume is much reduced. The thermal efficiency is improved 24% over a BWR. The coolant void reactivity is negative by placing thin zirconium-hydride layers between seeds and blankets. The power costs would be much reduced compared with those of a light water reactor (LWR) and a liquid-metal fast breeder reactor. The concept is based on the huge amount of experience with the water coolant technology of LWRs and FPPs. The oxidation of stainless steel cladding is avoided by adopting a much lower coolant temperature than that of the FPP

  16. Stocking density effects on production characteristics and body composition of market size cobia, Rachycentron canadum, reared in recirculating aquaculture systems

    Science.gov (United States)

    Production density in excess of a critical threshold can result in a negative relationship between stocking density and fish production. This study was conducted to evaluate production characteristics of juvenile cobia Rachycentron canadum, reared to market size in production-scale recirculating aq...

  17. The effects of carbon dioxide on performance and histopathology of rainbow trout Oncorhynchus mykiss in water recirculation aquaculture systems

    Science.gov (United States)

    Chronic exposure to elevated levels of dissolved carbon dioxide (CO2) has been linked to reduced growth, physiological disturbances and negative health outcomes in intensively reared fish. Although pumping to a degassing tower can lower concentrations of dissolved CO2 in water recirculation aquacult...

  18. FluoRAS Sensor - Online organic matter for optimising recirculating aquaculture systems

    DEFF Research Database (Denmark)

    Hambly, Adam; Stedmon, Colin

    2018-01-01

    FluorRAS will develop a sensor that can save recycled fish farms 30% per year in water and energy consumption for water treatment, as well as optimize nitrogen removal. The sensor will be developed in a partnership between engineers (Krüger A / S) and researchers (DTU), and the product will be made...... both the maintenance of necessary water quality and water treatment costs. Loss of production due to poor water quality is expensive and can be avoided with correct sensor systems. Accumulation of dissolved organic matter and nutrients in the water reduce the effectiveness of UV treatment, is a source...... of nutrition for opportunistic pathogens, and reduces the effectiveness of the biofilter's removing ammonia. Modern recycling systems are therefore dependent on a network of online sensors that monitor and respond to changes in water quality, but currently there is a need for a sensor to monitor...

  19. Influence of Fishmeal-Free Diets on Microbial Communities in Atlantic Salmon (Salmo salar) Recirculation Aquaculture Systems.

    Science.gov (United States)

    Schmidt, Victor; Amaral-Zettler, Linda; Davidson, John; Summerfelt, Steven; Good, Christopher

    2016-08-01

    Reliance on fishmeal as a primary protein source is among the chief economic and environmental concerns in aquaculture today. Fishmeal-based feeds often require harvest from wild fish stocks, placing pressure on natural ecosystems and causing price instability. Alternative diet formulations without the use of fishmeal provide a potential solution to this challenge. Although the impact of alternative diets on fish performance, intestinal inflammation, palatability, and gut microbiota has been a topic of recent interest, less is known about how alternative feeds impact the aquaculture environment as a whole. The recent focus on recirculating aquaculture systems (RAS) and the closed-containment approach to raising food fish highlights the need to maintain stable environmental and microbiological conditions within a farm environment. Microbial stability in RAS biofilters is particularly important, given its role in nutrient processing and water quality in these closed systems. If and how the impacts of alternative feeds on microbial communities in fish translate into changes to the biofilters are not known. We tested the influence of a fishmeal-free diet on the microbial communities in RAS water, biofilters, and salmon microbiomes using high-throughput 16S rRNA gene V6 hypervariable region amplicon sequencing. We grew Atlantic salmon (Salmo salar) to market size in six replicate RAS tanks, three with traditional fishmeal diets and three with alternative-protein, fishmeal-free diets. We sampled intestines and gills from market-ready adult fish, water, and biofilter medium in each corresponding RAS unit. Our results provide data on how fish diet influences the RAS environment and corroborate previous findings that diet has a clear influence on the microbiome structure of the salmon intestine, particularly within the order Lactobacillales (lactic acid bacteria). We conclude that the strong stability of taxa likely involved in water quality processing regardless of diet (e

  20. Applying rotary jet heads for mixing and mass transfer in a forced recirculation tank reactor system

    DEFF Research Database (Denmark)

    Nordkvist, Mikkel; Grotkjær, Thomas; Hummer, J.S.

    2003-01-01

    or an external loop.In this study, we determine mixing times in water and CMC solutions and oxygen mass transfer coefficients in water for a tank reactor system where a small fraction of the total liquid volume is rapidly circulated through an external loop and injected through the nozzles of rotary jet heads....... The system has a very simple design with no internal baffles or heat exchange area, and between batches the rotary jet heads are used for cleaning in place.Mixing time decreases and mass transfer increases with increasing circulation flow rate. For nozzle diameters between 5.5 and 10 mm and with one or two...... rotary jet heads, it is shown that a remarkable saving in power input for a fixed mixing time or mass transfer coefficient can be obtained by using a large nozzle diameter and two rather than one rotary jet heads.At the experimental conditions of the study the system is scaleable by simple formulas...

  1. Addition of Molecular Adsorbent Recirculating System (MARS® Albumin Dialysis for the Preoperative Management of Jaundiced Patients with Hilar Cholangiocarcinoma

    Directory of Open Access Journals (Sweden)

    Jean-Marc Regimbeau

    2013-09-01

    Full Text Available The preoperative management of hilar cholangiocarcinoma (HC with jaundice focuses on decreasing the total serum bilirubin level (SBL by performing preoperative biliary drainage (PBD. However, it takes about 6-8 weeks for the SBL to fall at a sufficient extent. The objective of this preliminary study was to evaluate the impact of Molecular Adsorbent Recirculating System (MARS® dialysis (in association with PBD on SBL decrease. From January 2010 to January 2011, we prospectively selected all jaundiced patients admitted to our university hospital for resectable HC and requiring PBD prior to major hepatectomy. The PBD was followed by 3 sessions of MARS dialysis over a period of 72 h. A total of 10 patients with HC were screened and two of them were included (Bismuth-Corlette stage IIIa, gender ratio 1, median age 68 years. The initial SBL in the two patients was 328 and 242 μmol/l, respectively. After three MARS dialysis sessions, the SBL had fallen by 30 and 52%, respectively. After the end of each session, there was a SBL rebound of about 10 μmol/l. The MARS decreased the serum creatinine level, the platelet count and the prothrombin index, but did not modify the serum albumin level. Pruritus disappeared after one and two sessions, respectively. MARS-related morbidity included hypotension (n = 1, tachycardia (n = 1, thrombocytopenia (n = 2 and anaemia (n = 1. When combined with PBD, MARS dialysis appears to accelerate the decrease in SBL and thus may enable earlier surgery. This hypothesis must be validated in a larger study.

  2. Establishment of a real-time PCR method for quantification of geosmin-producing Streptomyces spp. in recirculating aquaculture systems.

    Science.gov (United States)

    Auffret, Marc; Pilote, Alexandre; Proulx, Emilie; Proulx, Daniel; Vandenberg, Grant; Villemur, Richard

    2011-12-15

    Geosmin and 2-methylisoborneol (MIB) have been associated with off-flavour problems in fish and seafood products, generating a strong negative impact for aquaculture industries. Although most of the producers of geosmin and MIB have been identified as Streptomyces species or cyanobacteria, Streptomyces spp. are thought to be responsible for the synthesis of these compounds in indoor recirculating aquaculture systems (RAS). The detection of genes involved in the synthesis of geosmin and MIB can be a relevant indicator of the beginning of off-flavour events in RAS. Here, we report a real-time polymerase chain reaction (qPCR) protocol targeting geoA sequences that encode a germacradienol synthase involved in geosmin synthesis. New geoA-related sequences were retrieved from eleven geosmin-producing Actinomycete strains, among them two Streptomyces strains isolated from two RAS. Combined with geoA-related sequences available in gene databases, we designed primers and standards suitable for qPCR assays targeting mainly Streptomyces geoA. Using our qPCR protocol, we succeeded in measuring the level of geoA copies in sand filter and biofilters in two RAS. This study is the first to apply qPCR assays to detect and quantify the geosmin synthesis gene (geoA) in RAS. Quantification of geoA in RAS could permit the monitoring of the level of geosmin producers prior to the occurrence of geosmin production. This information will be most valuable for fish producers to manage further development of off-flavour events. Copyright © 2011 Elsevier Ltd. All rights reserved.

  3. Computational Fluid Dynamics Analysis of an Evaporative Cooling System

    Directory of Open Access Journals (Sweden)

    Kapilan N.

    2016-11-01

    Full Text Available The use of chlorofluorocarbon based refrigerants in the air-conditioning system increases the global warming and causes the climate change. The climate change is expected to present a number of challenges for the built environment and an evaporative cooling system is one of the simplest and environmentally friendly cooling system. The evaporative cooling system is most widely used in summer and in rural and urban areas of India for human comfort. In evaporative cooling system, the addition of water into air reduces the temperature of the air as the energy needed to evaporate the water is taken from the air. Computational fluid dynamics is a numerical analysis and was used to analyse the evaporative cooling system. The CFD results are matches with the experimental results.

  4. Modeling of Nonlinear Marine Cooling Systems with Closed Circuit Flow

    DEFF Research Database (Denmark)

    Hansen, Michael; Stoustrup, Jakob; Bendtsen, Jan Dimon

    2011-01-01

    We consider the problem of constructing a mathematical model for a specific type of marine cooling system. The system in question is used for cooling the main engine and main engine auxiliary components, such as diesel generators, turbo chargers and main engine air coolers for certain classes...

  5. Heat pump system with selective space cooling

    Science.gov (United States)

    Pendergrass, J.C.

    1997-05-13

    A reversible heat pump provides multiple heating and cooling modes and includes a compressor, an evaporator and heat exchanger all interconnected and charged with refrigerant fluid. The heat exchanger includes tanks connected in series to the water supply and a condenser feed line with heat transfer sections connected in counterflow relationship. The heat pump has an accumulator and suction line for the refrigerant fluid upstream of the compressor. Sub-cool transfer tubes associated with the accumulator/suction line reclaim a portion of the heat from the heat exchanger. A reversing valve switches between heating/cooling modes. A first bypass is operative to direct the refrigerant fluid around the sub-cool transfer tubes in the space cooling only mode and during which an expansion valve is utilized upstream of the evaporator/indoor coil. A second bypass is provided around the expansion valve. A programmable microprocessor activates the first bypass in the cooling only mode and deactivates the second bypass, and vice-versa in the multiple heating modes for said heat exchanger. In the heating modes, the evaporator may include an auxiliary outdoor coil for direct supplemental heat dissipation into ambient air. In the multiple heating modes, the condensed refrigerant fluid is regulated by a flow control valve. 4 figs.

  6. The stochastic-cooling system for COSY-Juelich

    International Nuclear Information System (INIS)

    Brittner, P.; Danzglock, R.; Hacker, H.U.; Maier, R.; Pfister, U.; Prasuhn, D.; Singer, H.; Spiess, W.; Stockhorst, H.

    1991-01-01

    The cooling in the Cooler Synchrotron COSY will work in the ranges: Band 1: 1 to 1.8 GHz, Band 2: 1.8 to 3 GHz. The system allows cooling in the energy range of 0.8 to 2.5 GeV. The stochastic-cooling system is under development. Cooling characteristics have been calculated. The tanks are similar to those of the CERN-AC. But the COSY parameters have required changes of the tank design. Active RF components have been developed for COSY. Measured results are presented

  7. Recirculating aquaculture system for high density production of the calanoid copepod Acartia tonsa (Dana)

    DEFF Research Database (Denmark)

    Vu, Minh Thi Thuy; Øie, Gunvor; Reinertsen, Helge

    2013-01-01

    The calanoid copepod Acartia tonsa (Dana) is one of the most promising copepod species for marine larviculture. This species has a wide tolerance to temperature and salinity, small size, can produce resting eggs. All their nauplii, copepodites and adults can be use as excellent feeds for marine...... capacity. A. tonsa fed the unicellular algae Rhodomonas baltica were registered for four weeks in triplicate 50 L tanks in each system. Water quality parameters were recorded daily for temperature, oxygen, pH, salinity, particles and every five days for nitrogenous waste and bacteria through...... the similar survival, growth, and reproduction, yet the nauplii developed into copepodites faster in RAS (110h) compared to FTAS (158h). This can be an indication for the potential for culturing or maintaining A. tonsa nauplii and early copepodite stages at higher densities before feeding larvae of marine...

  8. Fate of water borne therapeutic agents and associated effects on nitrifying biofilters in recirculating aquaculture systems

    DEFF Research Database (Denmark)

    Pedersen, Lars-Flemming

    be described as a concentration-dependent exponential decay. HP was found to be enzymatically eliminated by microorganisms, with degradation rates correlated to organic matter content and microbial abundance. Nitrification performance was not affected by HP when applied in dosages less than 30 mg/L, whereas...... prolonged multiple HP dosages at 10 mg/L were found to inhibit nitrite oxidation in systems with low organic loading. PAA decay was found to be concentration-dependent. It had a considerable negative effect on nitrite oxidation over a prolonged period of time when applied at a dosage ≥2 mg/L. PAA and HP...... decay patterns were significantly affected by water quality parameters, i.e. at low organic matter content HP degradation was impeded due to microbial inhibition. FISH analysis on biofilm samples from two different types of RAS showed that Nitrosomonas oligotropha was the dominant ammonia oxidizing...

  9. Integrated systems for power plant cooling and wastewater management

    International Nuclear Information System (INIS)

    Haith, D.A.

    1975-01-01

    The concept of integrated management of energy and water resources, demonstrated in hydropower development, may be applicable to steam-generated power, also. For steam plants water is a means of disposing of a waste product, which is unutilized energy in the form of heat. One framework for the evolution of integrated systems is the consideration of possible technical linkages between power plant cooling and municipal wastewater management. Such linkages include the use of waste heat as a mechanism for enhancing wastewater treatment, the use of treated wastewater as make-up for evaporative cooling structures, and the use of a pond or reservoir for both cooling and waste stabilization. This chapter reports the results of a systematic evaluation of possible integrated systems for power plant cooling and waste water management. Alternatives were analyzed for each of three components of the system--power plant cooling (condenser heat rejection), thermally enhanced waste water treatment, and waste water disposal. Four cooling options considered were evaporative tower, open cycle, spray pond, and cooling pond. Three treatment alternatives considered were barometric condenser-activated sludge, sectionalized condenser-activated sludge, and cooling/stabilization pond. Three disposal alternatives considered were ocean discharge, land application (spray irrigation), and make-up (for evaporative cooling). To facilitate system comparisons, an 1100-MW nuclear power plant was selected. 31 references

  10. Experiments on novel solar heating and cooling system

    International Nuclear Information System (INIS)

    Wang Yiping; Cui Yong; Zhu Li; Han Lijun

    2008-01-01

    Solar heating and nocturnal radiant cooling techniques are united to produce a novel solar heating and cooling system. The radiant panel with both heating and cooling functions can be used as structural materials for the building envelope, which realizes true building integrated utilization of solar energy. Based on the natural circulation principle, the operation status can be changed automatically between the heating cycle and the cooling cycle. System performances under different climate conditions using different covers on the radiant panel are studied. The results show that the novel solar heating and cooling system has good performance of heating and cooling. For the no cover system, the daily average heat collecting efficiency is 52% with the maximum efficiency of 73%, while at night, the cooling capacity is about 47 W/m 2 on a sunny day. On a cloudy day, the daily average heat collecting efficiency is 47% with the maximum of 84%, while the cooling capacity is about 33 W/m 2 . As a polycarbonate (PC) panel or polyethylene film are used as covers, the maximum heat collecting efficiencies are 75% and 72% and the daily average heat collecting efficiencies are 61% and 58%, while the cooling capacities are 50 W/m 2 and 36 W/m 2 , respectively

  11. Recirculation System for Geothermal Energy Recovery in Sedimentary Formations: Laboratory Experiments and Numerical Simulations

    Science.gov (United States)

    Elkhoury, J. E.; Detwiler, R. L.; Serajian, V.; Bruno, M. S.

    2012-12-01

    Geothermal energy resources are more widespread than previously thought and have the potential for providing a significant amount of sustainable clean energy worldwide. In particular, hot permeable sedimentary formations provide many advantages over traditional geothermal recovery and enhanced geothermal systems in low permeability crystalline formations. These include: (1) eliminating the need for hydraulic fracturing, (2) significant reduction in risk for induced seismicity, (3) reducing the need for surface wastewater disposal, (4) contributing to decreases in greenhouse gases, and (5) potential use for CO2 sequestration. Advances in horizontal drilling, completion, and production technology from the oil and gas industry can now be applied to unlock these geothermal resources. Here, we present experimental results from a laboratory scale circulation system and numerical simulations aimed at quantifying the heat transfer capacity of sedimentary rocks. Our experiments consist of fluid flow through a saturated and pressurized sedimentary disc of 23-cm diameter and 3.8-cm thickness heated along its circumference at a constant temperature. Injection and production ports are 7.6-cm apart in the center of the disc. We used DI de-aired water and mineral oil as working fluids and explored temperatures from 20 to 150 oC and flow rates from 2 to 30 ml/min. We performed experiments on sandstone samples (Castlegate and Kirby) with different porosity, permeability and thermal conductivity to evaluate the effect of hydraulic and thermal properties on the heat transfer capacity of sediments. The producing fluid temperature followed an exponential form with time scale transients between 15 and 45 min. Steady state outflow temperatures varied between 60% and 95% of the set boundary temperature, higher percentages were observed for lower temperatures and flow rates. We used the flow and heat transport simulator TOUGH2 to develop a numerical model of our laboratory setting. Given

  12. Application of fuzzy control in cooling systems save energy design

    Energy Technology Data Exchange (ETDEWEB)

    Chen, M.L.; Liang, H.Y. [Chienkuo Technology Univ., Changhua, Taiwan (China). Dept. of Electrical Engineering

    2005-07-01

    A fuzzy logic programmable logic controller (PLC) was used to control the cooling systems of frigorific equipment. Frigorific equipment is used to move unwanted heat outside of building in order to control indoor temperatures. The aim of the fuzzy logic PLC was to improve the energy efficiency of the cooling system. Control of the cooling pump and cooling tower in the system was based on the water temperature of the condenser during frigorific system operation. A human computer design for the cooling system control was used to set speeds and to automate and adjust the motor according to the fuzzy logic controller. It was concluded that if fuzzy logic controllers are used with all components of frigorific equipment, energy efficiency will be significantly increased. 5 refs., 3 tabs., 9 figs.

  13. Coupled simulation of a system for the utilization of exhaust heat and cooling of the interior of commercial vehicles; Gekoppelte Simulation eines Abgaswaermenutzungs- und Fahrzeugkuehlsystems im Nutzfahrzeug

    Energy Technology Data Exchange (ETDEWEB)

    Ambros, Peter; Fezer, Axel; Kapitel, Julian [TheSys GmbH, Kirchentellinsfurt (Germany)

    2012-11-01

    Based on a simulation software called GT-Suite by Gamma Technology, a one-dimensional model of a waste-heat recovery system with utility vehicle boundary conditions was developed. Using this model, it is possible to simulate stationary operating points of this type WHR. A Clausius-Rankine cycle is used in the power-heat cogeneration. The Clausius-Rankine cycle is linked to the exhaust system by two boilers. The first boiler is installed in the main exhaust steam, the second boiler is implemented in the exhaust gas recirculation. Besides the waste-heat recovery system, the integrated cooling system of the vehicle is also modeled. (orig.)

  14. Fundamental research on the cooling characteristic of passive containment cooling system

    International Nuclear Information System (INIS)

    Kawakubo, M.; Kikura, H.; Aritomi, M.; Inaba, N.; Yamauchi, T.

    2004-01-01

    The objective of this experimental study is to clarify the heat transfer characteristics of the Passive Containment Cooling System (PCCS) with vertical heat transfer tubes for investigating the influence of non-condensable gas on condensation. Furthermore, hence we obtained new experimental correlation formula to calculate the transients in system temperature and pressure using the simulation program of the PCCS. The research was carried out using a forced circulation experimental loop, which simulates atmosphere inside PCCS with vertical heat transfer tubes if a loss of coolant accident (LOCA) occurs. The experimental facility consists of cooling water supply systems, an orifice flowmeter, and a tank equipped with the heat transfer pipe inside. Cooling water at a constant temperature is injected to the test part of heat transfer pipe vertically installed in the tank by forced circulation. At that time, the temperature of the cooling water between inlet and outlet of the pipe was measured to calculate the overall heat transfer coefficient between the cooling water and atmosphere in the tank. Thus, the heat transfer coefficient between heat transfer surface and the atmosphere in the tank considering the influence of the non-condensable gas was clarified. An important finding of this study is that the amount of condensation in the steamy atmosphere including non-condensable gas depends on the cooling water Reynolds number, especially the concentration of non-condensable gas that has great influence on the amount of condensation. (authors)

  15. Post-accident cooling capacity analysis of the AP1000 passive spent fuel pool cooling system

    International Nuclear Information System (INIS)

    Su Xia

    2013-01-01

    The passive design is used in AP1000 spent fuel pool cooling system. The decay heat of the spent fuel is removed by heating-boiling method, and makeup water is provided passively and continuously to ensure the safety of the spent fuel. Based on the analysis of the post-accident cooling capacity of the spent fuel cooling system, it is found that post-accident first 72-hour cooling under normal refueling condition and emergency full-core offload condition can be maintained by passive makeup from safety water source; 56 hours have to be waited under full core refueling condition to ensure the safety of the core and the spent fuel pool. Long-term cooling could be conducted through reserved safety interface. Makeup measure is available after accident and limited operation is needed. Makeup under control could maintain the spent fuel at sub-critical condition. Compared with traditional spent fuel pool cooling system design, the AP1000 design respond more effectively to LOCA accidents. (authors)

  16. Percutaneous radiofrequency ablation of osteoid osteoma using cool-tip electrodes without the cooling system

    International Nuclear Information System (INIS)

    Miyazaki, Masaya; Miyazaki, Akiko; Nakajima, Takahito; Koyama, Yoshinori; Shinozaki, Tetsuya; Endo, Keigo; Aoki, Jun

    2011-01-01

    The aim of this study was to evaluate the efficacy of percutaneous radiofrequency ablation (RFA) for osteoid osteoma (OO) using cool-tip electrodes without the cooling system. A total of 17 patients (13 males, 4 females; mean age 19.1 years; range 7-49 years) with OO (tibia, n=7; femur, n=5; acetabulum, n=2; radius, n=1; talus, n=1; lumbar spine, n=1) underwent RFA. Using a cool-tip electrode without the cooling system, the lesion was heated to 90degC for 4 or 5 min. Procedures were considered technically successful if the electrode was placed into the nidus and the target temperature was reached and maintained for at least 4 min. Clinical success of the treatment was defined as complete or partial pain relief after RFA. All procedures were considered technically successful, although two patients encountered complications (pes equinus contracture, skin burn). Altogether, 16 of the 17 patients (94.1%) achieved complete or partial pain relief after primary RFA. Two patients had pain recurrence, with one of them treated successfully with a second RFA. The overall clinical success rate was 88.2%. Histological findings confirmed the presence of OO in 13 patients (76.5%). Percutaneous RFA of OO using cool-tip electrodes without the cooling system is a safe, effective procedure. (author)

  17. PERFORMANCE EVALUATION OF CEILING RADIANT COOLING SYSTEM IN COMPOSITE CLIMATE

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Anuj [Malaviya National Institute of Technology (MNIT), Jaipur, India; Mathur, Jyotirmay [Malaviya National Institute of Technology (MNIT), Jaipur, India; Bhandari, Mahabir S [ORNL

    2015-01-01

    Radiant cooling systems are proving to be an energy efficient solution due to higher thermal capacity of cooling fluid especially for the buildings that require individual zone controls and where the latent loads are moderate. The Conventional air conditioners work at very low temperature i.e.5-8 c (refrigerant evaporator inlet) while the radiant cooling systems, also referred as high temperature cooling system, work at high temperatures i.e. 14-18 c. The radiant cooling systems can maintain lower MRT (Mean Radiant Temperature) as ceiling panels maintain uniform temperature gradient inside room and provide higher human comfort. The radiant cooling systems are relatively new systems and their operation and energy savings potential are not quantified for a large number of buildings and operational parameters. Moreover, there are only limited numbers of whole building simulation studies have been carried out for these systems to have a full confidence in the capability of modelling tools to simulate these systems and predict the impact of various operating parameters. Theoretically, savings achieve due to higher temperature set point of chilled water, which reduces chiller-running time. However, conventional air conditioner runs continuously to maintain requisite temperature. In this paper, experimental study for performance evaluation of radiant cooling system carried out on system installed at Malaviya National Institute of Technology Jaipur. This paper quantifies the energy savings opportunities and effective temperature by radiant cooling system at different chilled water flow rates and temperature range. The data collected/ analysed through experimental study will used for calibration and validation of system model of building prepared in building performance simulation software. This validated model used for exploring optimized combinations of key parameters for composite climate. These optimized combinations will used in formulation of radiant cooling system

  18. Improvement of Cooling Performance of a Compact Thermoelectric Air Conditioner Using a Direct Evaporative Cooling System

    Science.gov (United States)

    Tipsaenporm, W.; Lertsatitthanakorn, C.; Bubphachot, B.; Rungsiyopas, M.; Soponronnarit, S.

    2012-06-01

    This paper presents the results of tests carried out to investigate the potential application of a direct evaporative cooling (DEC) system for improving the performance of a compact thermoelectric (TE) air conditioner. The compact TE air conditioner is composed of three TE modules. The cold and hot sides of the TE modules were fixed to rectangular fin heat sinks. The DEC system produced cooling air that was used to assist the release of heat from the heat sinks at the hot side of the TE modules. The results showed that the cooling air dry bulb temperature from the DEC system achieved drops of about 5.9°C in parallel with about a 33.4% rise in relative humidity. The cooling efficiency of the DEC system varies between 72.1% and 81.5%. It increases the cooling capacity of the compact TE air conditioner from 53.0 W to 74.5 W. The 21.5 W (40.6%) increase represents the difference between the compact air conditioner operating with ambient air flowing through the TE module's heat sinks, and the compact air conditioner operating with the cooler air from the DEC system flowing through the TE module's heat sinks. In both scenarios, electric current of 4.5 A was supplied to the TE modules. It also has been experimentally proven that the coefficient of performance (COP) of the compact TE air conditioner can be improved by up to 20.9% by incorporating the DEC system.

  19. Cooling systems for waste heat. Cooling systems, review and selection criteria. Kuehlsysteme fuer Abwaerme. Kuehlsysteme, Ueberblick und Auswahlkriterien

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, W. (Jaeggi, Wallisellen (Switzerland))

    1990-05-01

    In many areas of ventilation, air-conditioning and refrigeration engineering, chemical and process engineering and energy production waste heat occurs. If a reduction in energy losses or heat recovery is not possible waste heat has to be drawn off through cooling systems. For this the following systems can be used: dry cooling systems, dry cooler with spray system, open-cycle wet cooler, hybrid dry cooler, and closed-cycle wet cooler. Particularly hybrid cooling systems can give acceptable solutions when the results with other systems are only unsatisfactory. (BWI).

  20. Numerical study of a novel dew point evaporative cooling system

    Energy Technology Data Exchange (ETDEWEB)

    Riangvilaikul, B.; Kumar, S. [Energy Field of Study, School of Environment, Resources and Development, Asian Institute of Technology, P.O. Box 4, Klong Luang, Pathumthani 12120 (Thailand)

    2010-11-15

    Dew point evaporative cooling system is an alternative to vapor compression air conditioning system for sensible cooling of ventilation air. This paper presents the theoretical performance of a novel dew point evaporative cooling system operating under various inlet air conditions (covering dry, moderate and humid climate) and influence of major operating parameters (namely, velocity, system dimension and the ratio of working air to intake air). A model of the dew point evaporative cooling system has been developed to simulate the heat and mass transfer processes. The outlet air conditions and system effectiveness predicted by the model using numerical method for known inlet parameters have been validated with experimental findings and with recent literature. The model was used to optimize the system parameters and to investigate the system effectiveness operating under various inlet air conditions. (author)

  1. Closed-cycle cooling systems for nuclear power plants

    International Nuclear Information System (INIS)

    Santini, Lorenzo

    2006-01-01

    The long experience in the field of closed-cycle cooling systems and high technological level of turbo machines and heat exchangers concurs to believe in the industrial realizability of nuclear systems of high thermodynamic efficiency and intrinsic safety [it

  2. Solar heating and cooling technical data and systems analysis

    Science.gov (United States)

    Christensen, D. L.

    1977-01-01

    The research activities described herein were concentrated on the areas of economics, heating and cooling systems, architectural design, materials characteristics, climatic conditions, educational information packages, and evaluation of solar energy systems and components.

  3. RAMI analysis for DEMO HCPB blanket concept cooling system

    Energy Technology Data Exchange (ETDEWEB)

    Dongiovanni, Danilo N., E-mail: danilo.dongiovanni@enea.it [ENEA, Unità Tecnica Fusione, ENEA C. R. Frascati (Italy); Pinna, Tonio [ENEA, Unità Tecnica Fusione, ENEA C. R. Frascati (Italy); Carloni, Dario [KIT, Institute of Neutron Physics and Reactor Technology (INR) – KIT (Germany)

    2015-10-15

    Highlights: • RAMI (reliability, availability, maintainability and inspectability) preliminary assessment for HCPB blanket concept cooling system. • Reliability block diagram (RBD) modeling and analysis for HCPB primary heat transfer system (PHTS), coolant purification system (CPS), pressure control system (PCS), and secondary cooling system. • Sensitivity analysis on system availability performance. • Failure models and repair models estimated on the base of data from the ENEA fusion component failure rate database (FCFRDB). - Abstract: A preliminary RAMI (reliability, availability, maintainability and inspectability) assessment for the HCPB (helium cooled pebble bed) blanket cooling system based on currently available design for DEMO fusion power plant is presented. The following sub-systems were considered in the analysis: blanket modules, primary cooling loop including pipework and steam generators lines, pressure control system (PCS), coolant purification system (CPS) and secondary cooling system. For PCS and CPS systems an extrapolation from ITER Test Blanket Module corresponding systems was used as reference design in the analysis. Helium cooled pebble bed (HCPB) system reliability block diagrams (RBD) models were implemented taking into account: system reliability-wise configuration, operating schedule currently foreseen for DEMO, maintenance schedule and plant evolution schedule as well as failure and corrective maintenance models. A simulation of plant activity was then performed on implemented RBDs to estimate plant availability performance on a mission time of 30 calendar years. The resulting availability performance was finally compared to availability goals previously proposed for DEMO plant by a panel of experts. The study suggests that inherent availability goals proposed for DEMO PHTS system and Tokamak auxiliaries are potentially achievable for the primary loop of the HCPB concept cooling system, but not for the secondary loop. A

  4. Design Requirements of an Advanced HANARO Reactor Core Cooling System

    International Nuclear Information System (INIS)

    Park, Yong Chul; Ryu, Jeong Soo

    2007-12-01

    An advanced HANARO Reactor (AHR) is an open-tank-type and generates thermal power of 20 MW and is under conceptual design phase for developing it. The thermal power is including a core fission heat, a temporary stored fuel heat in the pool, a pump heat and a neutron reflecting heat in the reflector vessel of the reactor. In order to remove the heat load, the reactor core cooling system is composed of a primary cooling system, a primary cooling water purification system and a reflector cooling system. The primary cooling system must remove the heat load including the core fission heat, the temporary stored fuel heat in the pool and the pump heat. The purification system must maintain the quality of the primary cooling water. And the reflector cooling system must remove the neutron reflecting heat in the reflector vessel of the reactor and maintain the quality of the reflector. In this study, the design requirement of each system has been carried out using a design methodology of the HANARO within a permissible range of safety. And those requirements are written by english intend to use design data for exporting the research reactor

  5. Elimination of root-infecting pathogens in recirculation water from closed cultivation systems by ultra-violet radiation

    International Nuclear Information System (INIS)

    Runia, W.T.

    1994-01-01

    The development from growing in border soil to soilless cultures has not resulted in the disappearance of soil-borne diseases. Most root-infecting pathogens also occur in these new cultivation systems. Some pathogens such as Pythium, Phytophthora, cucumber green mottle mosaic virus and tomato mosaic virus are easily transmitted in recirculation water as is Olpidium, the vector of several viruses. To exclude any risk of dispersal of plant pathogens the water has to be sterilised before re-use. Rainwater collected from the glasshouse roof can also be contaminated with pathogens. When this rainwater is used for irrigation water it should be disinfected first. Currently water disinfection by heating or ozonisation is applied on some 450 nurseries. Initially ultra-violet(UV) radiation was not effective against plant pathogens. Only at a low capacity of 18 l h -1 and a high UV-dose of 430 mJ cm -2 could fungal spores be eliminated in nutrient solution. A low capacity however implies a poor turbulence in the water, resulting in varying UV-doses in the different water layers. Two new UV-installations with high capacities were tested for their efficacy against fungal and viral plant pathogens. One installation was equipped with a high-pressure and the other with a low-pressure mercury vapour lamp. In both installations a sandfilter first removed organic particles from the water. A UV-dose from the high-pressure lamp of 28 mJ cm -2 reduced the infectivity of conidia of Fusarium oxysporum f.sp lycopersici by 90 % resulting in a 99.9 % reduction at 84 mJ cm -2 . The low-pressure lamp completely eliminated conidia of Fusarium at a UV-dose of 70 mJ cm -2 . Tomato mosaic virus was reduced by 99 % using a UV-dose of 100 mJ cm -2 in both installations. Ultra-violet radiation can be effective against plant pathogens providing the dose under controlled conditions is sufficient. Numerous growers use UV-radiation for the disinfection of water in closed cultivation systems. (author)

  6. Replacement of the cooling system of the TRIGA Mainz reactor

    International Nuclear Information System (INIS)

    Menke, H.

    1988-01-01

    The inspection of the reactor facility resulted in a recommendation to install a new heat exchanger and at the same time to separate the primary cooling circuit and the water purification system. Due to possible the deposition of lime and organic matter on the tubes, the heat transfer rate has decreased. In the meantime a rule has been introduced, according to which the pressure in the secondary cooling circuit must be permanently higher than in the primary cooling circuit which prompted the design of a new cooling system. The detail planning was completed in December 1987. In response to the regulatory requirements a motion for a replacement of the cooling system was submitted to the authorities. The start of the procedure is possible a year after the obtaining of the licenses. In the planning of the changes an upgrading of the steady state power to 300 kW is envisioned

  7. Thermal Hydraulic Analysis of RPV Support Cooling System for HTGR

    International Nuclear Information System (INIS)

    Min Qi; Wu Xinxin; Li Xiaowei; Zhang Li; He Shuyan

    2014-01-01

    Passive safety is now of great interest for future generation reactors because of its reduction of human interaction and avoidance of failures of active components. reactor pressure vessel (RPV) support cooling system (SCS) for high temperature gas-cooled reactor (HTGR) is a passive safety system and is used to cool the concrete seats for the four RPV supports at its bottom. The SCS should have enough cooling capacity to ensure the temperature of the concrete seats for the supports not exceeding the limit temperature. The SCS system is composed of a natural circulation water loop and an air cooling tower. In the water loop, there is a heat exchanger embedded in the concrete seat, heat is transferred by thermal conduction and convection to the cooling water. Then the water is cooled by the air cooler mounted in the air cooling tower. The driving forces for water and air are offered by the density differences caused by the temperature differences. In this paper, the thermal hydraulic analysis for this system was presented. Methods for decoupling the natural circulation and heat transfer between the water loop and air flow were introduced. The operating parameters for different working conditions and environment temperatures were calculated. (author)

  8. Evaluation of two cooling systems under a firefighter coverall

    NARCIS (Netherlands)

    Teunissen, L.P.J.; Wang, L.C.; Chou, S.N.; Huang, C.; Jou, G.T.; Daanen, H.A.M.

    2014-01-01

    Firemen often suffer from heat strain. This study investigated two chest cooling systems for use under a firefighting suit. In nine male subjects, a vest with water soaked cooling pads and a vest with water perfused tubes were compared to a control condition. Subjects performed 30 min walking and 10

  9. Ammonia and nitrite removal rates in a closed recirculating-water system, under three load rates of rainbow trout Oncorhynchus mykiss

    OpenAIRE

    Arredondo-Figueroa, J. L.; Ingle de la Mora, G; Guerrero-Legarreta, I; Ponce-Palafox, J. T.; Barriga-Sosa, I. de los A.

    2007-01-01

    Nitrification and denitrification rates of inorganic nitrogen were studied in a closed recirculating-water system, comparing three load rates of rainbow trout Oncorhynchus mykiss (89, 156 and 194 kg in each tank with two repetitions). Six self-cleaning water circular fish tanks with a volume of 4.3 m³ were used, maintaining a 3.94 m³/day of average flow rate and constant aeration. A total of 371 rainbow trout, 524 ± 8 g initial wet weight were introduced in the system and fed with a commercia...

  10. Conceptual design study on simplified and safer cooling systems for sodium cooled FBRs

    International Nuclear Information System (INIS)

    Hayafune, Hiroki; Shimakawa, Yoshio; Ishikawa, Hiroyasu; Kubota, Kenichi; Kobayashi, Jun; Kasai, Shigeo

    2000-06-01

    The objective of this study is to create the FBR plant concepts increasing economy and safety for the Phase-I 'Feasibility Studies on Commercialized Fast Reactor System'. In this study, various concepts of simplified 2ry cooling system for sodium cooled FBRs are considered and evaluated from the view points of technological feasibility, economy, and safety. The concepts in the study are considered on the basis of the following points of view. 1. To simplify 2ry cooling system by moderating and localizing the sodium-water reaction in the steam generator of the FBRs. 2. To simplify 2ry cooling system by eliminating the sodium-water reaction using integrated IHX-SG unit. 3. To simplify 2ry cooling system by eliminating the sodium-water reaction using a power generating system other than the steam generator. As the result of the study, 12 concepts and 3 innovative concepts are proposed. The evaluation study for those concepts shows the following technical prospects. 1. 2 concepts of integrated IHX-SG unit can eliminate the sodium-water reaction. Separated IHX and SG tubes unit using Lead-Bismuth as the heat transfer medium. Integrated IHX-SG unit using copper as the heat transfer medium. 2. Cost reduction effect by simplified 2ry cooling system using integrated IHX-SG unit is estimated 0 to 5%. 3. All of the integrated IHX-SG unit concepts have more weight and larger size than conventional steam generator unit. The weight of the unit during transporting and lifting would limit capacity of heat transfer system. These evaluation results will be compared with the results in JFY 2000 and used for the Phase-II study. (author)

  11. Analysis of a solid desiccant cooling system with indirect evaporative cooling

    DEFF Research Database (Denmark)

    Bellemo, Lorenzo

    investigates the performance of a solid desiccant cooling system implementing in-direct evaporative cooling processes. The aim is to quantify the system thermal and electrical performance for varying component dimensions and operating conditions, and to identify its range of applicability. This information...... evaporative cooler. Detailed steady state numerical models are developed and implemented in MATLAB. The models need to be accurate and require low computational effort, for analysing the internal heat and mass transfer processes, as well as carrying out repetitive design and optimization simulations......-to-air heat exchanger for enhancing cooling capacity and thermal performance. The system perfor-mance is investigated considering regeneration temperatures between 50 ºC and 90 ºC, which enable low temperature heat sources, such as solar energy or waste heat, to be used. The effects of several geometrical...

  12. Heat Driven Cooling in District Energy Systems; Vaermedriven Kyla

    Energy Technology Data Exchange (ETDEWEB)

    Rydstrand, Magnus; Martin, Viktoria; Westermark, Mats [Royal Inst. of Technology, Stockholm (Sweden). Dept. of Chemical Engineering and Technology

    2004-07-01

    high costs. However heat sinks are unavoidable from a system perspective and there are potential cost savings since a low-pressure steam turbines will not be required if heat driven cooling is implemented. The fuel utilization for some technologies (not necessarily the best technology) was evaluated in two different scenarios: 1) with electricity production from coal; and 2) with electricity production from natural gas. It is shown in the scenarios that the heat driven cooling technologies give lower fuel consumption as compared producing electricity as an intermediate product before cooling is produced. Further it should be noted that electricity is produced, not consumed, if heat is used directly for the production of cooling. We claim that cost effective solutions for district heat driven chillers and/or combined production of electricity and district cooling can be found in all climates with high enough density of heating and cooling demands. It was found that district heat driven chillers can be very energy efficient in warm and humid climates since desiccant systems are an effective way of handling latent cooling loads. In dry climates, with low latent loads, water distributed cooling has a large potential and absorption cooling will give high fuel utilization seen from a system perspective. In climates where water shortage is a problem it is possible that the temperature lift of the conventional absorption chiller has to be increased in order to be able to use dry cooling towers. The temperature lift can be increased by changing the chiller design or by using a different working pair. Heat driven cooling can be integrated into an energy system in different ways. In USA and Japan, district heating is not well developed. Instead small, distributed combined heat and power (CHP) plants with high exhaust temperatures are widespread. Cooling is often produced, in these regions, through absorption cooling (using heat from CHP) or compression chillers depending on

  13. Exergy analysis of a gas-hydrate cool storage system

    International Nuclear Information System (INIS)

    Bi, Yuehong; Liu, Xiao; Jiang, Minghe

    2014-01-01

    Based on exergy analysis of charging and discharging processes in a gas-hydrate cool storage system, the formulas for exergy efficiency at the sensible heat transfer stage and the phase change stage corresponding to gas-hydrate charging and discharging processes are obtained. Furthermore, the overall exergy efficiency expressions of charging, discharging processes and the thermodynamic cycle of the gas-hydrate cool storage system are obtained. By using the above expressions, the effects of number of transfer units, the inlet temperatures of the cooling medium and the heating medium on exergy efficiencies of the gas-hydrate cool storage system are emphatically analyzed. The research results can be directly used to evaluate the performance of gas-hydrate cool storage systems and design more efficient energy systems by reducing the sources of inefficiency in gas-hydrate cool storage systems. - Highlights: • Formulas for exergy efficiency at four stages are obtained. • Exergy efficiency expressions of two processes and one cycle are obtained. • Three mainly influencing factors on exergy efficiencies are analyzed. • With increasing the inlet temperature of cooling medium, exergy efficiency increases. • With decreasing the inlet temperature of heating medium, exergy efficiency increases

  14. Thermodynamic analysis of cooling systems for nuclear power stations condenser

    International Nuclear Information System (INIS)

    Beck, A.

    1985-06-01

    This work is an attempt to concentrate on the thermodynamic theory, the engineering solution and the quantities of water needed for the operation of a wet as well as a wet/dry cooling towers coupled to a nuclear turbine condenser,. About two hundred variables are needed for the design of a condenser - cooling tower system. In order to make the solution fast and handy, a computer model was developed. The amount of water evaporation from cooling towers is a function of the climate conditions prevailing around the site. To achieve an authentic analysis, the meteorological data of the northern Negev was used. The total amount of water necessary to add to the system in a year time of operation is large and is a function of both the blow-down rate and the evaporation. First estimations show that the use of a combined system, wet/dry cooling tower, is beneficial in the northern Negev area. Such a system can reduce significantly the amount of wasted fresh water. Lack of international experience is the major problem in the acceptability of wet/dry cooling towers. The technology of a wet cooling tower using sea water is also discussed where no technical or engineering limitations were found. This work is an attempt to give some handy tools for making the choice of cooling systems for nuclear power plants easier

  15. Preoperational test report, primary ventilation condenser cooling system

    Energy Technology Data Exchange (ETDEWEB)

    Clifton, F.T.

    1997-10-29

    This represents the preoperational test report for the Primary Ventilation Condenser Cooling System, Project W-030. Project W-030 provides a ventilation upgrade for the four Aging Waste Facility tanks. The system uses a closed chilled water piping loop to provide offgas effluent cooling for tanks AY101, AY102, AZ1O1, AZ102; the offgas is cooled from a nominal 100 F to 40 F. Resulting condensation removes tritiated vapor from the exhaust stack stream. The piping system includes a package outdoor air-cooled water chiller with parallel redundant circulating pumps; the condenser coil is located inside a shielded ventilation equipment cell. The tests verify correct system operation and correct indications displayed by the central Monitor and Control System.

  16. Preoperational test report, primary ventilation condenser cooling system

    International Nuclear Information System (INIS)

    Clifton, F.T.

    1997-01-01

    This represents the preoperational test report for the Primary Ventilation Condenser Cooling System, Project W-030. Project W-030 provides a ventilation upgrade for the four Aging Waste Facility tanks. The system uses a closed chilled water piping loop to provide offgas effluent cooling for tanks AY101, AY102, AZ1O1, AZ102; the offgas is cooled from a nominal 100 F to 40 F. Resulting condensation removes tritiated vapor from the exhaust stack stream. The piping system includes a package outdoor air-cooled water chiller with parallel redundant circulating pumps; the condenser coil is located inside a shielded ventilation equipment cell. The tests verify correct system operation and correct indications displayed by the central Monitor and Control System

  17. Containment atmosphere cooling system for experimental fast reactor 'JOYO'

    International Nuclear Information System (INIS)

    Sasaki, Mikio; Hoshi, Akio; Sato, Morihiko; Takeuchi, Kaoru

    1979-01-01

    The experimental fast reactor ''JOYO'', the first sodium-cooled fast reactor in Japan, achieved the initially licensed full power operation (50 MW) in July 1978 and is now under steady operation. Toshiba has participated in the construction of this reactor as a leading manufacturer and supplied various systems. This article outlines the design philosophy, system concepts and the operating experience of the containment atmosphere cooling system which has many design interfaces throughout the whole plant and requires especially high reliability. The successful performance of this system during the reactor full-power operation owes to the spot cooling design philosophy and to the preoperational adjustment of heat load during the preheating period of reactor cooling system peculiar to FBR. (author)

  18. CAREM 25: Suppression pool cooling and purification system

    International Nuclear Information System (INIS)

    Carlevaris, Rodolfo; Patrignani, Alberto; Vindrola, Carlos; Palmerio, Hector D.; Quiroz, Horacio; Ramilo, Lucia B.

    2000-01-01

    The suppression pool cooling and purification system has the following main functions: purify and cool water from the suppression pool, cool and send water to the residual heat extraction system, and transfer water to the fuel element transference channel. In case of Loss of Coolant Accident (LOCA), the system sends water from the suppression pool to the spray network, thus cooling and reducing pressure in the primary containment. The system has been designed in accordance with the requirements of the following standards: ANSI/ANS 52.1; ANSI/ANS 57.2; ANSI/ANS 56.2; ANSI/ANS 59.1; ANSI/ANS 58.3; ANSI/ANS 58.9; and ANSI/ANS 56.5. The design of the system fulfils all the assigned functions. (author)

  19. CAREM-25. Suppression Pool Cooling and Purification System

    International Nuclear Information System (INIS)

    Carlevaris, Rodolfo; Palmerio, D.; Patrignani, A.; Quiroz, H.; Ramilo, L.; Vindrola, C.

    2000-01-01

    The Suppression Pool Cooling and Purification System has the following main functions: purify and cool water from the Suppression Pool, cool and send water to the Residual Heat Extraction System, and transfer water to the Fuel Element Transference Channel. In case of Loss of Coolant Accident (LOCA), the system sends water from the Suppression Pool to the spray network, thus cooling and reducing pressure in the primary containment.The system has been designed in accordance with the requirements of the following standards ANSI/ANS 52.1 [1], ANSI/ANS 57.2 [2], ANSI/ANS 56.2 [3], ANSI/ANS 59.1 [4] ANSI/ANS 58.3 [5], ANSI/ANS 58.9 [6], and ANSI/ANS 56.5 [7]. The design of the system fulfils all the assigned functions

  20. Cooling System Design Options for a Fusion Reactor

    Science.gov (United States)

    Natalizio, Antonio; Collén, Jan; Vieider, Gottfried

    1997-06-01

    The objective of a fusion power reactor is to produce electricity safely and reliably. Accordingly, the design, objective of the heat transport system is to optimize power production, safety, and reliability. Such an optimization process, however, is constrained by many factors, including, among others: public safety, worker safety, steam cycle efficiency, reliability, and cost. As these factors impose conflicting requirements, there is a need to find an optimum design solution, i.e., one that satisfies all requirements, but not necessarily each requirement optimally. The SEAFP reactor study developed helium-cooled and water-cooled models for assessment purposes. Among other things, the current study demonstrates that neither model offers an optimum solution. Helium cooling offers a high steam cycle efficiency but poor reliability for the cooling of high heat flux components (divertor and first wall). Alternatively, water cooling offers a low steam cycle efficiency, but reasonable reliability for the cooling of such components. It is concluded that an optimum solution includes helium cooling of low heat flux components and water cooling of high heat flux components. Relative to the SEAFP helium model, this hybrid system enhances safety and reliability, while retaining the high steam cycle efficiency of that model.

  1. Investigation of Microbunching Instabilities in Modern Recirculating Accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Tsai, Cheng [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States)

    2017-05-21

    challenging issues for such high-brightness or high-intensity beam transport, as it would degrade lasing performance in the fourth-generation light sources, reduce cooling efficiency in electron cooling facilities, and compromise the luminosity of colliding beams in lepton or lepton-hadron colliders. The dissertation work will focus on the MBI in modern recirculating electron accelerators. It has been known that the collective interactions, the coherent synchrotron radiation (CSR) and the longitudinal space charge (LSC) forces, can drive MBI. The CSR effect is a collective phenomenon in which the electrons in a curved motion, e.g. a bending dipole, emit radiation at a scale comparable to the micro-bunched structure of the bunch distribution. The LSC effect stems from non-uniformity of the charge distribution, acts as plasma oscillation, and can eventually accumulate an amount of energy modulation when the beam traverses a long section of a beamline. MBI can be seeded by non-uniformity or shot noise of the beam, which originates from granularity of the elementary charge. Through the aforementioned collective effects, the modulation of the bunch sub-structure can be amplified and, once the beam-wave interaction formed a positive feedback, can result in MBI. The problem of MBI has been intensively studied for linac-based facilities and for storage-ring accelerators. However, systematic studies for recirculation machines are still very limited and form a knowledge gap. Because of the much more complicated machine configuration of the recirculating accelerators than that of linacs, the existing MBI analysis needs to be extended to accommodate the high-brightness particle beam transport in modern recirculating accelerators. This dissertation is focused on theoretical investigation of MBI in such machine configuration in the following seven themes: (1) Development and generalization of MBI theory The theoretical formulation has been extended so as to be applicable to a general

  2. Treatment of vinasses - recirculation

    Directory of Open Access Journals (Sweden)

    Germán Andrés Castro Moreno

    2009-08-01

    Full Text Available The purpose of this minireview is to give an overview of treatments that have been applied on the vinasse, residue from the alcoholic fermentation; appoint some of its advantages and disadvantages, and then submit recirculation, as one of the best options from an economic point of view and easy implementation, for those who are not interested in the ethanol byproducts.

  3. Active cooling system for Tokamak in-vessel operation manipulator

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, Jianjun, E-mail: yuanjj@sjtu.edu.cn; Chen, Tan; Li, Fashe; Zhang, Weijun; Du, Liang

    2015-10-15

    Highlights: • We summarized most of the challenges of fusion devices to robot systems. • Propose an active cooling system to protect all of the necessary components. • Trial design test and theoretical analysis were conducted. • Overall implementation of the active cooling system was demonstrated. - Abstract: In-vessel operation/inspection is an indispensable task for Tokamak experimental reactor, for a robot/manipulator is more capable in doing this than human being with more precise motion and less risk of damaging the ambient equipment. Considering the demanding conditions of Tokamak, the manipulator should be adaptable to rapid response in the extreme conditions such as high temperature, vacuum and so on. In this paper, we propose an active cooling system embedded into such manipulator. Cameras, motors, gearboxes, sensors, and other mechanical/electrical components could then be designed under ordinary conditions. The cooling system cannot only be a thermal shield since the components are also heat sources in dynamics. We carry out a trial test to verify our proposal, and analyze the active cooling system theoretically, which gives a direction on the optimization by varying design parameters, components and distribution. And based on thermal sensors monitoring and water flow adjusting a closed-loop feedback control of temperature is added to the system. With the preliminary results, we believe that the proposal gives a way to robust and inexpensive design in extreme environment. Further work will concentrate on overall implementation and evaluation of this cooling system with the whole inspection manipulator.

  4. Evaluation of Active Cooling Systems for Non-Residential Buildings

    Directory of Open Access Journals (Sweden)

    M.A. Othuman Mydin

    2014-05-01

    Full Text Available Cooling systems are an essential element in many facets of modern society including cars, computers and buildings. Cooling systems are usually divided into two types: passive and active. Passive cooling transfers heat without using any additional energy while active cooling is a type of heat transfer that uses powered devices such as fans or pumps. This paper will focus on one particular type of passive cooling: air-conditioning systems. An air-conditioning system is defined as controlled air movement, temperature, humidity and cleanliness of a building area. Air conditioning consists of cooling and heating. Therefore, the air-conditioning system should be able to add and remove heat from the area. An air-conditioning system is defined as a control or treatment of air in a confined space. The process that occurs is the air-conditioning system absorbs heat and dust while, at the same time, cleaning the air breathed into a closed space. The purpose of air-conditioning is to maintain a comfortable atmosphere for human life and to meet user requirements. In this paper, air-conditioning systems for non-residential buildings will be presented and discussed.

  5. A model for radionuclide transport in the Cooling Water System

    International Nuclear Information System (INIS)

    Kahook, S.D.

    1992-08-01

    A radionuclide transport model developed to assess radiological levels in the K-reactor Cooling Water System (CWS) in the event of an inadvertent process water (PW) leakage to the cooling water (CW) in the heat exchangers (HX) is described. During and following a process water leak, the radionuclide transport model determines the time-dependent release rates of radionuclide from the cooling water system to the environment via evaporation to the atmosphere and blow-down to the Savannah River. The developed model allows for delay times associated with the transport of the cooling water radioactivity through cooling water system components. Additionally, this model simulates the time-dependent behavior of radionuclides levels in various CWS components. The developed model is incorporated into the K-reactor Cooling Tower Activity (KCTA) code. KCTA allows the accident (heat exchanger leak rate) and the cooling tower blow-down and evaporation rates to be described as time-dependent functions. Thus, the postulated leak and the consequence of the assumed leak can be modelled realistically. This model is the first of three models to be ultimately assembled to form a comprehensive Liquid Pathway Activity System (LPAS). LPAS will offer integrated formation, transport, deposition, and release estimates for radionuclides formed in a SRS facility. Process water and river water modules are forthcoming as input and downstream components, respectively, for KCTA

  6. System and method for pre-cooling of buildings

    Science.gov (United States)

    Springer, David A.; Rainer, Leo I.

    2011-08-09

    A method for nighttime pre-cooling of a building comprising inputting one or more user settings, lowering the indoor temperature reading of the building during nighttime by operating an outside air ventilation system followed, if necessary, by a vapor compression cooling system. The method provides for nighttime pre-cooling of a building that maintains indoor temperatures within a comfort range based on the user input settings, calculated operational settings, and predictions of indoor and outdoor temperature trends for a future period of time such as the next day.

  7. System for cooling the containment vessel of a nuclear reactor

    International Nuclear Information System (INIS)

    Costes, Didier.

    1982-01-01

    The invention concerns a post-accidental cooling system for a nuclear reactor containment vessel. This system includes in series a turbine fed by the moist air contained in the vessel, a condenser in which the air is dried and cooled, a compressor actuated by the turbine and a cooling exchanger. The cold water flowing through the condenser and in the exchanger is taken from a tank outside the vessel and injected by a pump actuated by the turbine. The application is for nuclear reactors under pressure [fr

  8. Hybrid Cooling System for Industrial Application | Ezekwe | Nigerian ...

    African Journals Online (AJOL)

    Hybrid Cooling System for Industrial Application. ... PROMOTING ACCESS TO AFRICAN RESEARCH ... more than five times over that achieved by using the gas (air) phase alone. ... EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT

  9. Augmented cooling vest system subassembly: Design and analysis

    International Nuclear Information System (INIS)

    D’Angelo, Maurissa; D’Angelo, Joseph; Almajali, Mohammad; Lafdi, Khalid; Delort, Antoine; Elmansori, Mohamed

    2014-01-01

    Highlights: • Thermoelectric cooler (TEC) was employed to provide cooling air to cooling vest. • Aluminum cooling fins were used to exchange heat for hot and cold sides of TEC. • Performance of the system was determined and the experimental technique was described. • Heat sink is capable to remove additional heat and heat exchanger provides cooling air. • Future work is proposed to optimize the efficiency of the system. - Abstract: A prototype cooling engine consisting of thermoelectric coolers (TECs) was developed and designed. In this prototype, aluminum cooling fins were employed as the heat exchange method for both the hot and cold sides of the TEC. Aluminum fins were used to cool the ambient air through a heat exchanger and dissipate heat build up from the heat sink. This system was modeled and performance capabilities were determined. The experimental technique used to monitor parameters affecting the efficiency of the designed system was described. These parameters include the temperatures of the inlets and outlets of both heat exchanger and heat sink and the flow rate of the cooled air. The experiment was run under three input DC powers; 15 V, 18 V, and 21 V. As the power increased, both the flow rate and the temperature difference between the hot and cold side of thermoelectric cooler increased, demonstrating the heat sink capability to remove the additional heat. However, the temperature difference between the inlet and outlet of the heat exchanger decreases as the power increase. The findings demonstrated the effectiveness of this cooling system and future work is proposed to optimize the heat

  10. COMBINATION OF MOLECULAR ADSORBENT RECIRCULATING SYSTEM AND RADIOIODINE FOR THE TREATMENT OF CONCURRENT HYPERTHYROIDISM AND SEVERE LIVER DYSFUNCTION: A RETROSPECTIVE COHORT STUDY.

    Science.gov (United States)

    Zhang, Qing; Guan, Yanxing; Xiang, Tianxin; Liu, Shaozheng; Chen, Qingjie; Zhang, Qing

    2017-02-01

    The treatment of hyperthyroidism associated with severe liver dysfunction (LD) is a clinical challenge, and there has been no unified examination of this problem. The objective of this study was to assess the efficacy and safety of radioiodine ( 131 I) in combination with a molecular adsorbent recirculating system (MARS) for the treatment of hyperthyroidism complicated by severe liver LD. A total of 116 hyperthyroidism patients with concomitant LD who received MARS treatment were studied retrospectively. The patients were grouped according to whether or not they also received 131 I treatment: Group 1 (59 patients) received 131 I following MARS treatment, while Group 2 (57 cases) received only MARS. Clinical outcomes, including thyroid hormone levels, liver function parameters, and therapeutic efficacy were calculated. The overall response rate was significantly greater in Group 1 than in Group 2 (Ptreatment compared with before treatment (Ptreatments (Ptreatment of hyperthyroidism complicated by severe LD was effective and safe. The use of this system could rapidly improve liver function and metabolism, allowing 131 I therapy to be applied as early as possible with a shortened recovery time of liver function. ALSS = artificial liver support system ALT = alanine transaminase AST = aspartate transaminase ATD = antithyroid drugs DBil = direct bilirubin FT3 = free tri-iodothyronine FT4 = free thyroxine 131 I = radioiodine INR = international normalized ratio LD = liver dysfunction MARS = molecular adsorbent recirculating system MELD = model for end-stage liver disease PT = prothrombin time TBil = total bilirubin TSH = thyroid-stimulating hormone.

  11. Reuse of Treated Internal or External Wastewaters in the Cooling Systems of Coal-Based Thermoelectric Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Radisav Vidic; David Dzombak; Ming-Kai Hsieh; Heng Li; Shih-Hsiang Chien; Yinghua Feng; Indranil Chowdhury; Jason Monnell

    2009-06-30

    This study evaluated the feasibility of using three impaired waters - secondary treated municipal wastewater, passively treated abandoned mine drainage (AMD), and effluent from ash sedimentation ponds at power plants - for use as makeup water in recirculating cooling water systems at thermoelectric power plants. The evaluation included assessment of water availability based on proximity and relevant regulations as well as feasibility of managing cooling water quality with traditional chemical management schemes. Options for chemical treatment to prevent corrosion, scaling, and biofouling were identified through review of current practices, and were tested at bench and pilot-scale. Secondary treated wastewater is the most widely available impaired water that can serve as a reliable source of cooling water makeup. There are no federal regulations specifically related to impaired water reuse but a number of states have introduced regulations with primary focus on water aerosol 'drift' emitted from cooling towers, which has the potential to contain elevated concentrations of chemicals and microorganisms and may pose health risk to the public. It was determined that corrosion, scaling, and biofouling can be controlled adequately in cooling systems using secondary treated municipal wastewater at 4-6 cycles of concentration. The high concentration of dissolved solids in treated AMD rendered difficulties in scaling inhibition and requires more comprehensive pretreatment and scaling controls. Addition of appropriate chemicals can adequately control corrosion, scaling and biological growth in ash transport water, which typically has the best water quality among the three waters evaluated in this study. The high TDS in the blowdown from pilot-scale testing units with both passively treated mine drainage and secondary treated municipal wastewater and the high sulfate concentration in the mine drainage blowdown water were identified as the main challenges for blowdown

  12. Upgrade of the cooling water temperature measures system for HLS

    International Nuclear Information System (INIS)

    Guo Weiqun; Liu Gongfa; Bao Xun; Jiang Siyuan; Li Weimin; He Duohui

    2007-01-01

    The cooling water temperature measures system for HLS (Hefei Light Source) adopts EPICS to the developing platform and takes the intelligence temperature cruise instrument for the front control instrument. Data of temperatures are required by IOCs through Serial Port Communication, archived and searched by Channel Archiver. The system can monitor the real-time temperatures of many channels cooling water and has the function of history data storage, and data network search. (authors)

  13. Process integration: Cooling water systems design

    CSIR Research Space (South Africa)

    Gololo, KV

    2010-10-01

    Full Text Available stream_source_info Gololo2_2010.pdf.txt stream_content_type text/plain stream_size 17891 Content-Encoding UTF-8 stream_name Gololo2_2010.pdf.txt Content-Type text/plain; charset=UTF-8 The 13th Asia Pacific Confederation... results in a nonlinear program (NLP) formulation and the second case yields mixed integer nonlinear program (MINLP). In both cases the cooling towers operating capacity were debottlenecked without compromising the heat duties. The 13th Asia...

  14. Evaluation of a recirculating pond system for rearing juvenile freshwater mussels at White Sulphur Springs National Fish Hatchery, West Virginia, U.S.A.

    Science.gov (United States)

    Mummert, A.; Newcomb, T.J.; Neves, R.J.; Parker, B.

    2006-01-01

    A recirculating double-pond system at White Sulphur Springs National Fish Hatchery in West Virginia, U.S.A., was evaluated for suitability for culturing juvenile freshwater mussels. Newly metamorphosed juveniles of Villosa iris and Lampsilis fasciola were placed in the system, and their growth and survival were evaluated for 94 days. Throughout the study, parameters of water quality remained within ranges suitable for mussel survival. Planktonic algal densities in the pond system ranged from 2850 to 6892 cells/ml. Thirty-seven algal taxa were identified, primarily green algae (Chlorophyta), diatoms (Bacillariophyceae), and blue-green algae (Cyanoprokaryota). Over the culture period, juveniles of L. fasciola experienced significantly lower (p fasciola may indicate a failure of the flow-through pond environment to meet its habitat requirements or that variable microhabitat conditions within culture containers existed. Growth did not differ significantly between the species (p = 0.13). Survival of V. iris and growth of both species were similar to previous trials to culture juvenile mussels. Survival rates as high as 66.4% at 93 days for V. iris suggest that juveniles of some riverine species can be successfully cultured in a recirculating pond environment.

  15. Water cooling system for sintering furnaces of nuclear fuel pellets

    International Nuclear Information System (INIS)

    1996-01-01

    This work has as a main objective to develop a continuous cooling water system, which is necessary for the cooling of the sintering furnaces. This system is used to protect them as well as for reducing the water consumption, ejecting the heat generated into this furnaces and scattering it into the atmosphere in a fast and continuous way. The problem was defined and the reference parameters established, making the adequate research. The materials were selected as well as the length of the pipeline which will carry the secondary refrigerant fluid (water). Three possible solutions were tried,and evaluated, and from these, the thermal and economically most efficient option was selected. The layout of the solution was established and the theoretical construction of a cooling system for liquids using dichlorofluoromethane (R-22), as a refrigerant and a air cooled condenser, was accomplished. (Author)

  16. Adsorption Cooling System Using Metal-Impregnated Zeolite-4A

    Directory of Open Access Journals (Sweden)

    Somsuk Trisupakitti

    2016-01-01

    Full Text Available The adsorption cooling systems have been developed to replace vapor compression due to their benefits of being environmentally friendly and energy saving. We prepared zeolite-4A and experimental cooling performance test of zeolite-water adsorption system. The adsorption cooling test-rig includes adsorber, evaporator, and condenser which perform in vacuum atmosphere. The maximum and minimum water adsorption capacity of different zeolites and COP were used to assess the performance of the adsorption cooling system. We found that loading zeolite-4A with higher levels of silver and copper increased COP. The Cu6%/zeolite-4A had the highest COP at 0.56 while COP of zeolite-4A alone was 0.38. Calculating the acceleration rate of zeolite-4A when adding 6% of copper would accelerate the COP at 46%.

  17. Performance comparison between a solar driven rotary desiccant cooling system and conventional vapor compression system (performance study of desiccant cooling)

    International Nuclear Information System (INIS)

    Ge, T.S.; Ziegler, F.; Wang, R.Z.; Wang, H.

    2010-01-01

    Solar driven rotary desiccant cooling systems have been widely recognized as alternatives to conventional vapor compression systems for their merits of energy-saving and being eco-friendly. In the previous paper, the basic performance features of desiccant wheel have been discussed. In this paper, a solar driven two-stage rotary desiccant cooling system and a vapor compression system are simulated to provide cooling for one floor in a commercial office building in two cities with different climates: Berlin and Shanghai. The model developed in the previous paper is adopted to predict the performance of the desiccant wheel. The objectives of this paper are to evaluate and compare the thermodynamic and economic performance of the two systems and to obtain useful data for practical application. Results show that the desiccant cooling system is able to meet the cooling demand and provide comfortable supply air in both of the two regions. The required regeneration temperatures are 55 deg. C in Berlin and 85 deg. C in Shanghai. As compared to the vapor compression system, the desiccant cooling system has better supply air quality and consumes less electricity. The results of the economic analysis demonstrate that the dynamic investment payback periods are 4.7 years in Berlin and 7.2 years in Shanghai.

  18. Unlimited cooling capacity of the passive-type emergency core cooling system of the MARS reactor

    International Nuclear Information System (INIS)

    Bandini, G.; Caira, M.; Naviglio, A.; Sorabella, L.

    1995-01-01

    The MARS nuclear plant is equipped with a 600 MWth PWR type nuclear steam supply system, with completely innovative engineered core safeguards. The most relevant innovative safety system of this plant is its Emergency Core Cooling System, which is completely passive (with only one non static component). The Emergency Core Cooling System (ECCS) of the MARS reactor is natural-circulation, passive-type, and its intervention follows a core flow decrease, whatever was the cause. The operation of the system is based on a cascade of three fluid systems, functionally interfacing through heat exchangers; the first fluid system is connected to the reactor vessel and the last one includes an atmospheric-pressure condenser, cooled by external air. The infinite thermal capacity of the final heat sink provides the system an unlimited autonomy. The capability and operability of the system are based on its integrity and on the integrity of the primary coolant boundary (both of them are permanently enclosed in a pressurized containment; 100% redundancy is also foreseen) and on the operation of only one non static component (a check valve), with 400% redundancy. In the paper, all main thermal hydraulic transients occurring as a consequence of postulated accidents are analysed, to verify the capability of the passive-type ECCS to intervene always in time, without causing undue conditions of reduced coolability of the core (DNB, etc.), and to verify its capability to guarantee a long-term (indefinite) coolability of the core without the need of any external intervention. (author)

  19. Development of adsorption cooling system. 3

    Energy Technology Data Exchange (ETDEWEB)

    Kim, J.N.; Cho, S.H.; Chue, K.T.; You, Y.J.; Lee, K.H.; Eun, T.H. [Korea Inst. of Energy Research, Taejon (Korea, Republic of)

    1995-12-01

    This report describes the third year study to develop adsorption chiller using silica gel/water pair for the recovery of low level waste heat. A pilot plant was fabricated and tested. In a typical run, the cooling capacity of 1.66 USRT and COP of 0.38 was obtained under the following operating conditions; chilled water temperature of 12{yields}8.9 degree C, hot water temperature of 72.7 degree C, cooling water temperature of 23.2 degree C, and half cycle time of 600(s). The COP of the pilot plant is comparable to 0.4 of Nishiyodo pilot plant having 3.68 USRT. In order to enhance the thermal conductivity of adsorbent layer, consolidated silica gel and graphite block was prepared and its characteristics was analyzed. A slurry method using water was appropriate of silica gel and graphite in the block, in which adsorbed amount of water is not much smaller than that on silica gel, was 6:1. The thermal conductivity of this block was 6.53 W/mk which was 37 times larger than that of silica gel. (author). 12 refs., 37 figs., 8 tabs.

  20. Simulation of an active cooling system for photovoltaic modules

    International Nuclear Information System (INIS)

    Abdelhakim, Lotfi

    2016-01-01

    Photovoltaic cells are devices that convert solar radiation directly into electricity. However, solar radiation increases the photovoltaic cells temperature [1] [2]. The temperature has an influence on the degradation of the cell efficiency and the lifetime of a PV cell. This work reports on a water cooling technique for photovoltaic panel, whereby the cooling system was placed at the front surface of the cells to dissipate excess heat away and to block unwanted radiation. By using water as a cooling medium for the photovoltaic solar cells, the overheating of closed panel is greatly reduced without prejudicing luminosity. The water also acts as a filter to remove a portion of solar spectrum in the infrared band but allows transmission of the visible spectrum most useful for the PV operation. To improve the cooling system efficiency and electrical efficiency, uniform flow rate among the cooling system is required to ensure uniform distribution of the operating temperature of the PV cells. The aims of this study are to develop a 3D thermal model to simulate the cooling and heat transfer in Photovoltaic panel and to recommend a cooling technique for the PV panel. The velocity, pressure and temperature distribution of the three-dimensional flow across the cooling block were determined using the commercial package, Fluent. The second objective of this work is to study the influence of the geometrical dimensions of the panel, water mass flow rate and water inlet temperature on the flow distribution and the solar panel temperature. The results obtained by the model are compared with experimental results from testing the prototype of the cooling device.

  1. Simulation of an active cooling system for photovoltaic modules

    Energy Technology Data Exchange (ETDEWEB)

    Abdelhakim, Lotfi [Széchenyi István University of Applied Sciences, Department of Mathematics, P.O.Box 701, H-9007 Győr (Hungary)

    2016-06-08

    Photovoltaic cells are devices that convert solar radiation directly into electricity. However, solar radiation increases the photovoltaic cells temperature [1] [2]. The temperature has an influence on the degradation of the cell efficiency and the lifetime of a PV cell. This work reports on a water cooling technique for photovoltaic panel, whereby the cooling system was placed at the front surface of the cells to dissipate excess heat away and to block unwanted radiation. By using water as a cooling medium for the photovoltaic solar cells, the overheating of closed panel is greatly reduced without prejudicing luminosity. The water also acts as a filter to remove a portion of solar spectrum in the infrared band but allows transmission of the visible spectrum most useful for the PV operation. To improve the cooling system efficiency and electrical efficiency, uniform flow rate among the cooling system is required to ensure uniform distribution of the operating temperature of the PV cells. The aims of this study are to develop a 3D thermal model to simulate the cooling and heat transfer in Photovoltaic panel and to recommend a cooling technique for the PV panel. The velocity, pressure and temperature distribution of the three-dimensional flow across the cooling block were determined using the commercial package, Fluent. The second objective of this work is to study the influence of the geometrical dimensions of the panel, water mass flow rate and water inlet temperature on the flow distribution and the solar panel temperature. The results obtained by the model are compared with experimental results from testing the prototype of the cooling device.

  2. Active noise canceling system for mechanically cooled germanium radiation detectors

    Science.gov (United States)

    Nelson, Karl Einar; Burks, Morgan T

    2014-04-22

    A microphonics noise cancellation system and method for improving the energy resolution for mechanically cooled high-purity Germanium (HPGe) detector systems. A classical adaptive noise canceling digital processing system using an adaptive predictor is used in an MCA to attenuate the microphonics noise source making the system more deployable.

  3. System performance and economic analysis of solar-assisted cooling/heating system

    KAUST Repository

    Huang, B.J.; Wu, J.H.; Yen, R.H.; Wang, J.H.; Hsu, H.Y.; Hsia, C.J.; Yen, C.W.; Chang, J.M.

    2011-01-01

    The long-term system simulation and economic analysis of solar-assisted cooling/heating system (SACH-2) was carried out in order to find an economical design. The solar heat driven ejector cooling system (ECS) is used to provide part of the cooling

  4. A parametric study of solar operated cooling system

    International Nuclear Information System (INIS)

    Zagalei, Abdullatif Salin

    2006-01-01

    Because of energy for air conditioning has been the fastest-growing segment of energy of consumption market in Libya and generally in north Africa, and with the realization depleting nature of fossil fuel, solar cooling of buildings which leads to the improvement of human comfort represents a potentially significant application of solar energy where the availability of solar radiation meets with the cooling load demand. This application has been shown to be technically feasible but the equipment needs further investigative research to improve its performance and feasibility. A solar operated absorption cooling system with energy storage is selected. A latent heat storage would be a space saver for such application for solar energy. A system modeling is an essential activity in order to go for system simulation. A complete solar cooling system to be modeled through the thermodynamic analysis of each system components. Resulting a package of equations used directly to the system simulation in order to predict the system performance to obtain the optimum working conditions for the selected cooling system. A computer code which is used to simulate a series of calculations was written in Fortran language according to the constructed information flow diagram and simulation program flow char. For a typical input data a set of results are reported and discussed and shows that the selected system promises to be a good choice for air conditioning application in Libya specially for large building as storehouses, shopping centers, public administrative.(Author)

  5. Passive ventilation systems with heat recovery and night cooling

    DEFF Research Database (Denmark)

    Hviid, Christian Anker; Svendsen, Svend

    2008-01-01

    with little energy consumption and with satisfying indoor climate. The concept is based on using passive measures like stack and wind driven ventilation, effective night cooling and low pressure loss heat recovery using two fluid coupled water-to-air heat exchangers developed at the Technical University......In building design the requirements for energy consumption for ventilation, heating and cooling and the requirements for increasingly better indoor climate are two opposing factors. This paper presents the schematic layout and simulation results of an innovative multifunc-tional ventilation concept...... of Denmark. Through building integration in high performance offices the system is optimized to incorporate multiple functions like heating, cooling and ventilation, thus saving the expenses of separate cooling and heating systems. The simulation results are derived using the state-of-the-art building...

  6. Instrumentation for NBI SST-1 cooling water system

    International Nuclear Information System (INIS)

    Qureshi, Karishma; Patel, Paresh; Jana, M.R.

    2015-01-01

    Neutral Beam Injector (NBI) System is one of the heating systems for Steady state Superconducting Tokamak (SST-1). It is capable of generating a neutral hydrogen beam of power 0.5 MW at 30 kV. NBI system consists of following sub-systems: Ion source, Neutralizer, Deflection Magnet and Magnet Liner (ML), Ion Dump (ID), V-Target (VT), Pre Duct Scraper (PDS), Beam Transmission Duct (BTD) and Shine Through (ST). For better heat removal management purpose all the above sub-systems shall be equipped with Heat Transfer Elements (THE). During beam operation these sub-systems gets heated due to the received heat load which requires to be removed by efficient supplying water. The cooling water system along with the other systems (External Vacuum System, Gas Feed System, Cryogenics System, etc.) will be controlled by NBI Programmable Logic Control (PLC). In this paper instrumentation and its related design for cooling water system is discussed. The work involves flow control valves, transmitters (pressure, temperature and water flow), pH and conductivity meter signals and its interface with the NBI PLC. All the analog input, analog output, digital input and digital output signals from the cooling water system will be isolated and then fed to the NBI PLC. Graphical Users Interface (GUI) needed in the Wonderware SCADA for the cooling water system shall also be discussed. (author)

  7. Supplementary report: cooling water systems for Darlington G.S

    International Nuclear Information System (INIS)

    1975-08-01

    This report summarizes Ontario Hydro's existing aquatic environmental programs, presents results of these investigations, and outlines plans and activities for expanded aquatic environment studies including the evaluation of alternative cooling systems. This report outlines specific considerations regarding possible alternative cooling arrangements for the Darlington station. It concludes with a recommendation that a study be initiated to examine the potential benefits of using the heated discharge water in a warm water recreational centre. (author)

  8. Use of a temperature-initiated passive cooling system (TIPACS) for the modular high-temperature gas-cooled reactor cavity cooling system (RCCS)

    International Nuclear Information System (INIS)

    Forsberg, C.W.; Conklin, J.; Reich, W.J.

    1994-04-01

    A new type of passive cooling system has been invented (Forsberg 1993): the Temperature-Initiated Passive Cooling System (TIPACS). The characteristics of the TIPACS potentially match requirements for an improved reactor-cavity-cooling system (RCCS) for the modular high-temperature gas-cooled reactor (MHTGR). This report is an initial evaluation of the TIPACS for the MHTGR with a Rankines (steam) power conversion cycle. Limited evaluations were made of applying the TIPACS to MHTGRs with reactor pressure vessel temperatures up to 450 C. These temperatures may occur in designs of Brayton cycle (gas turbine) and process heat MHTGRs. The report is structured as follows. Section 2 describes the containment cooling issues associated with the MHTGR and the requirements for such a cooling system. Section 3 describes TIPACS in nonmathematical terms. Section 4 describes TIPACS's heat-removal capabilities. Section 5 analyzes the operation of the temperature-control mechanism that determines under what conditions the TIPACS rejects heat to the environment. Section 6 addresses other design and operational issues. Section 7 identifies uncertainties, and Section 8 provides conclusions. The appendixes provide the detailed data and models used in the analysis

  9. Use of a temperature-initiated passive cooling system (TIPACS) for the modular high-temperature gas-cooled reactor cavity cooling system (RCCS)

    Energy Technology Data Exchange (ETDEWEB)

    Forsberg, C.W.; Conklin, J.; Reich, W.J.

    1994-04-01

    A new type of passive cooling system has been invented (Forsberg 1993): the Temperature-Initiated Passive Cooling System (TIPACS). The characteristics of the TIPACS potentially match requirements for an improved reactor-cavity-cooling system (RCCS) for the modular high-temperature gas-cooled reactor (MHTGR). This report is an initial evaluation of the TIPACS for the MHTGR with a Rankines (steam) power conversion cycle. Limited evaluations were made of applying the TIPACS to MHTGRs with reactor pressure vessel temperatures up to 450 C. These temperatures may occur in designs of Brayton cycle (gas turbine) and process heat MHTGRs. The report is structured as follows. Section 2 describes the containment cooling issues associated with the MHTGR and the requirements for such a cooling system. Section 3 describes TIPACS in nonmathematical terms. Section 4 describes TIPACS`s heat-removal capabilities. Section 5 analyzes the operation of the temperature-control mechanism that determines under what conditions the TIPACS rejects heat to the environment. Section 6 addresses other design and operational issues. Section 7 identifies uncertainties, and Section 8 provides conclusions. The appendixes provide the detailed data and models used in the analysis.

  10. Theoretical model with experimental validation of a regenerative blower for hydrogen recirculation in a PEM fuel cell system

    Energy Technology Data Exchange (ETDEWEB)

    Badami, M.; Mura, M. [Dipartimento di Energetica, Politecnico di Torino, C.so Duca degli Abruzzi 24, Torino (Italy)

    2010-03-15

    A theoretical model of a regenerative blower used for the hydrogen recirculation of a Proton Exchange Membrane (PEM) fuel cell (FC) for automotive applications has been implemented and validated by means of experimental data. A momentum exchange theory was used to determine the head-flow rate curves, whereas the circulatory flow rate was determined through a theory based on the consideration of the centrifugal force field in the side channel and in the impeller vane grooves. The model allows a good forecast to be made of the blower behaviour, and only needs its main geometrical characteristics and some fluid-dynamic data as input. For this reason, the model could be very interesting, especially during the first sizing and the design activity of the blower. (author)

  11. Dry-type cooling systems in electric power production

    International Nuclear Information System (INIS)

    Li, K.W.

    1973-01-01

    This study indicates that the dry-type cooling tower could be adopted in this country as an alternative method for removing waste heat from power plants. The use of dry cooling towers would not only lead to a change of cooling system design, but also to a change of overall thermal design in a power generating system. The principal drawbacks to using dry cooling towers in a large steam-turbine plant are the generating capacity loss, increased fuel consumption and the high capital cost of the dry cooling towers. These economic penalties must be evaluated in each specific case against the benefits that may result from the use of dry cooling towers. The benefits are principally these: (1) Fewer constraints in the selection of power plant sites, (2) No thermal discharge to the natural water bodies, (3) Elimination of vapor plumes and water evaporation loss, and (4) Freedom of adding new units to an existing facility where inadequate water supply may otherwise rule out this possibility

  12. Emergency cooling system for nuclear reactors

    International Nuclear Information System (INIS)

    Frisch, E.; Andrews, H.N.

    1976-01-01

    Upon the occasion of loss of coolant in a nuclear reactor as when a coolant supply or return line breaks, or both lines break, borated liquid coolant from an emergency source is supplied in an amount to absorb heat being generated in the reactor even after the control rods have been inserted. The liquid coolant flows from pressurized storage vessels outside the reactor to an internal manifold from which it is distributed to unused control rod guide thimbles in the reactor fuel assemblies. Since the guide thimbles are mounted at predetermined positions relative to heat generating fuel elements in the fuel assemblies, holes bored at selected locations in the guide thimble walls, sprays the coolant against the reactor fuel elements which continue to dissipate heat but at a reduced level. The cooling water evaporates upon contacting the fuel rods thereby removing the maximum amount of heat (970 BTU per pound of water) and after heat absorption will leave the reactor in the form of steam through the break which is the cause of the accident to help assure immediate core cooldown

  13. Parametric Effects of Debris Source, Environments, and Design Options on the Overall Performance of ECCS Recirculation Sump

    International Nuclear Information System (INIS)

    Park, Jong Woon; Kim, Chang Hyun

    2006-01-01

    A primary safety issue regarding long-term recirculation core cooling following a LOCA (Loss of Coolant Accident) is that LOCA-generated debris may be transported to the recirculation sump screen, resulting in adverse blockage on the sump screen and deterioration of available NPSH (Net Positive Suction Head) of ECCS (Emergency Core Cooling System). USNRC identified this as Generic Safety Issue (GSI) 191 and issued the Generic Letter 04-02 to resolve the issue. The GL required that all PWR owners perform an engineering assessment of their containment recirculation sumps to ensure they will not suffer from excessive blockage. The guidance report (GR) for PWR sump performance evaluation has been developed by NEI (Nuclear Energy Institute) and approved by the USNRC. In Korea, Korea Hydro and Nuclear Power Company (KHNP) is performing the assessment of Kori unit 1 and planning for remaining plants in the near future. The objective of the assessment is to derive required plant modifications including insulation, sump screen, etc. To derive the cost-effective modification items, we have to get insight on the parametric effects of plant conditions and design. Therefore, the general effects of debris source, containment environments and debris interceptor on the performance of ECCS recirculation sump with respect to head loss are parametrically investigated

  14. Replacement inhibitors for tank farm cooling coil systems

    International Nuclear Information System (INIS)

    Hsu, T.C.

    1995-01-01

    Sodium chromate has been an effective corrosion inhibitor for the cooling coil systems in Savannah River Site (SRS) waste tanks for over 40 years. Due to their age and operating history, cooling coils occasionally fail allowing chromate water to leak into the environment. When the leaks spill 10 lbs. or more of sodium chromate over a 24-hr period, the leak incidents are classified as Unusual Occurrences (UO) per CERCLA (Comprehensive Environmental Response, Compensation and Liability Act). The cost of reporting and cleaning up chromate spills prompted High Level Waste Engineering (HLWE) to initiate a study to investigate alternative tank cooling water inhibitor systems and the associated cost of replacement. Several inhibitor systems were investigated as potential alternatives to sodium chromate. All would have a lesser regulatory impact, if a spill occurred. However, the conversion cost is estimated to be $8.5 million over a period of 8 to 12 months to convert all 5 cooling systems. Although each of the alternative inhibitors examined is effective in preventing corrosion, there is no inhibitor identified that is as effective as chromate. Assuming 3 major leaks a year (the average over the past several years), the cost of maintaining the existing inhibitor was estimated at $0.5 million per year. Since there is no economic or regulatory incentive to replace the sodium chromate with an alternate inhibitor, HLWE recommends that sodium chromate continue to be used as the inhibitor for the waste tank cooling systems

  15. Cooling power technology at a turning point

    International Nuclear Information System (INIS)

    Hese, L.H.

    1978-01-01

    From freshwater cooling and efflux condenser cooling to wet recirculation cooling, hybrid and dry cooling towers, cooling tower technology has seen a development characterized by higher cooling tower costs and reduced power plant efficiency. Therefore, all research work done at the moment concentrates on making up for the economic losses connected with improved environmental protection. (orig.) [de

  16. Development of a higher power cooling system for lithium targets.

    Science.gov (United States)

    Phoenix, B; Green, S; Scott, M C; Bennett, J R J; Edgecock, T R

    2015-12-01

    The accelerator based Boron Neutron Capture Therapy beam at the University of Birmingham is based around a solid thick lithium target cooled by heavy water. Significant upgrades to Birmingham's Dynamitron accelerator are planned prior to commencing a clinical trial. These upgrades will result in an increase in maximum achievable beam current to at least 3 mA. Various upgrades to the target cooling system to cope with this increased power have been investigated. Tests of a phase change coolant known as "binary ice" have been carried out using an induction heater to provide a comparable power input to the Dynamitron beam. The experimental data shows no improvement over chilled water in the submerged jet system, with both systems exhibiting the same heat input to target temperature relation for a given flow rate. The relationship between the cooling circuit pumping rate and the target temperature in the submerged jet system has also been tested. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Development and application of online Stelmor Controlled Cooling System

    International Nuclear Information System (INIS)

    Yu Wanhua; Chen Shaohui; Kuang Yonghai; Cao Kaichao

    2009-01-01

    An online Stelmor Controlled Cooling System (SCCS) has been developed successfully for the Stelmor production line, which can communicate with the material flow management system and Program Logic Control System (PLCs) automatically through local network. This online model adopts Implicit Finite Difference Time Domain (FDTD) method to calculate temperature evolution and phase transformation during the production process and predicts final properties. As Continuous Cooling Temperature (CCT) curves of various steels can be coupled in the model, it can predict the latent heat rise and range of phase transformation for various steels, which can provide direct guidance for new steel development and optimization of present Stelmor cooling process. This unique online system has been installed in three Stelmor production lines at present with good results.

  18. Control of Non-linear Marine Cooling System

    DEFF Research Database (Denmark)

    Hansen, Michael; Stoustrup, Jakob; Bendtsen, Jan Dimon

    2011-01-01

    We consider the problem of designing control laws for a marine cooling system used for cooling the main engine and auxiliary components aboard several classes of container vessels. We focus on achieving simple set point control for the system and do not consider compensation of the non-linearitie......-linearities, closed circuit flow dynamics or transport delays that are present in the system. Control laws are therefore designed using classical control theory and the performance of the design is illustrated through two simulation examples....

  19. COMMIX analysis of AP-600 Passive Containment Cooling System

    International Nuclear Information System (INIS)

    Chang, J.F.C.; Chien, T.H.; Ding, J.; Sun, J.G.; Sha, W.T.

    1992-01-01

    COMMIX modeling and basic concepts that relate components, i.e., containment, water film cooling, and natural draft air flow systems. of the AP-600 Passive Containment Cooling System are discussed. The critical safety issues during a postulated accident have been identified as (1) maintaining the liquid film outside the steel containment vessel, (2) ensuring the natural convection in the air annulus. and (3) quantifying both heat and mass transfer accurately for the system. The lack of appropriate heat and mass transfer models in the present analysis is addressed. and additional assessment and validation of the proposed models is proposed

  20. System for cooling hybrid vehicle electronics, method for cooling hybrid vehicle electronics

    Science.gov (United States)

    France, David M.; Yu, Wenhua; Singh, Dileep; Zhao, Weihuan

    2017-11-21

    The invention provides a single radiator cooling system for use in hybrid electric vehicles, the system comprising a surface in thermal communication with electronics, and subcooled boiling fluid contacting the surface. The invention also provides a single radiator method for simultaneously cooling electronics and an internal combustion engine in a hybrid electric vehicle, the method comprising separating a coolant fluid into a first portion and a second portion; directing the first portion to the electronics and the second portion to the internal combustion engine for a time sufficient to maintain the temperature of the electronics at or below 175.degree. C.; combining the first and second portion to reestablish the coolant fluid; and treating the reestablished coolant fluid to the single radiator for a time sufficient to decrease the temperature of the reestablished coolant fluid to the temperature it had before separation.

  1. Transient Performance of Air-cooled Condensing Heat Exchanger in Long-term Passive Cooling System during Decay Heat Load

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Myoung Jun; Lee, Hee Joon [Kookmin University, Seoul (Korea, Republic of); Moon, Joo Hyung; Bae, Youngmin; Kim, Young-In [KAERI, Daejeon (Korea, Republic of)

    2015-05-15

    In the event of a 'loss of coolant accident'(LOCA) and a non-LOCA, the secondary passive cooling system would be activated to cool the steam in a condensing heat exchanger that is immersed in an emergency cooldown tank (ECT). Currently, the capacities of these ECTs are designed to be sufficient to remove the sensible and residual heat from the reactor coolant system for 72 hours after the occurrence of an accident. After the operation of a conventional passive cooling system for an extended period, however, the water level falls as a result of the evaporation from the ECT, as steam is emitted from the open top of the tank. Therefore, the tank should be refilled regularly from an auxiliary water supply system when the system is used for more than 72 hours. Otherwise, the system would fail to dissipate heat from the condensing heat exchanger due to the loss of the cooling water. Ultimately, the functionality of the passive cooling system would be seriously compromised. As a passive means of overcoming the water depletion in the tank, Kim et al. applied for a Korean patent covering the concept of a long-term passive cooling system for an ECT even after 72 hours. This study presents transient performance of ECT with installing air-cooled condensing heat exchanger under decay heat load. The cooling capacity of an air-cooled condensing heat exchanger was evaluated to determine its practicality.

  2. Safety analysis of reactor's cooling system

    International Nuclear Information System (INIS)

    1999-01-01

    Results of the analysis of reactor's RBMK-1500 coolant system during normal operation mode, hydrodynamic testing and in the case of earthquake are presented. Analysis was performed using RELAP5 code. Calculations showed the most vulnerable place in the reactor's coolant system. It was found that in the case of earthquake the horizontal support system of drum separator could be damaged

  3. Emergency core cooling systems in CANDU nuclear power plants

    International Nuclear Information System (INIS)

    1981-12-01

    This report contains the responses by the Advisory Committee on Nuclear Safety to three questions posed by the Atomic Energy Control Board concerning the need for Emergency Core Cooling Systems (ECCS) in CANDU nuclear power plants, the effectiveness requirement for such systems, and the extent to which experimental evidence should be available to demonstrate compliance with effectiveness standards

  4. Prototype solar heating and cooling systems including potable hot water

    Science.gov (United States)

    1978-01-01

    Progress is reviewed in the development, delivery, and support of two prototype solar heating and cooling systems including potable hot water. The system consisted of the following subsystems: collector, auxiliary heating, potable hot water, storage, control, transport, and government-furnished site data acquisition.

  5. A System for Cooling inside a Glove Box

    Science.gov (United States)

    Sanz, Martial

    2010-01-01

    An easy, efficient, reliable, and low-cost method of constructing a cooling system using a simple circulating pump is described. The system is employed in conjunction with an inert atmosphere glove box to achieve the synthesis of air- and moisture-sensitive compounds inside the glove box at controlled, low temperatures without contaminating the…

  6. AUTOMOTIVE DIESEL MAINTENANCE 1. UNIT IV, MAINTAINING THE COOLING SYSTEM--DETROIT DIESEL ENGINES.

    Science.gov (United States)

    Human Engineering Inst., Cleveland, OH.

    THIS MODULE OF A 30-MODULE COURSE IS DESIGNED TO DEVELOP AN UNDERSTANDING OF THE OPERATION AND MAINTENANCE OF THE DIESEL ENGINE COOLING SYSTEM. TOPICS ARE PURPOSE OF THE COOLING SYSTEM, CARE MAINTENANCE OF THE COOLING SYSTEM, COOLING SYSTEM COMPONENTS, AND TROUBLESHOOTING TIPS. THE MODULE CONSISTS OF A SELF-INSTRUCTIONAL BRANCH PROGRAMED TRAINING…

  7. Techno-economic process design of a commercial-scale amine-based CO_2 capture system for natural gas combined cycle power plant with exhaust gas recirculation

    International Nuclear Information System (INIS)

    Ali, Usman; Agbonghae, Elvis O.; Hughes, Kevin J.; Ingham, Derek B.; Ma, Lin; Pourkashanian, Mohamed

    2016-01-01

    Highlights: • EGR is a way to enhance the CO_2 content with reduction in design variables and cost. • Both process and economic analyses are essential to reach the optimum design variables. • Commercial-scale NGCC with and without EGR is presented. • Process design of the amine-based CO_2 capture plant is evaluated for with and without EGR. - Abstract: Post-combustion CO_2 capture systems are gaining more importance as a means of reducing escalating greenhouse gas emissions. Moreover, for natural gas-fired power generation systems, exhaust gas recirculation is a method of enhancing the CO_2 concentration in the lean flue gas. The present study reports the design and scale-up of four different cases of an amine-based CO_2 capture system at 90% capture rate with 30 wt.% aqueous solution of MEA. The design results are reported for a natural gas-fired combined cycle system with a gross power output of 650 MW_e without EGR and with EGR at 20%, 35% and 50% EGR percentage. A combined process and economic analysis is implemented to identify the optimum designs for the different amine-based CO_2 capture plants. For an amine-based CO_2 capture plant with a natural gas-fired combined cycle without EGR, an optimum liquid to gas ratio of 0.96 is estimated. Incorporating EGR at 20%, 35% and 50%, results in optimum liquid to gas ratios of 1.22, 1.46 and 1.90, respectively. These results suggest that a natural gas-fired power plant with exhaust gas recirculation will result in lower penalties in terms of the energy consumption and costs incurred on the amine-based CO_2 capture plant.

  8. Adiabatic cooling processes in frustrated magnetic systems with pyrochlore structure

    Science.gov (United States)

    Jurčišinová, E.; Jurčišin, M.

    2017-11-01

    We investigate in detail the process of adiabatic cooling in the framework of the exactly solvable antiferromagnetic spin-1/2 Ising model in the presence of the external magnetic field on an approximate lattice with pyrochlore structure. The behavior of the entropy of the model is studied and exact values of the residual entropies of all ground states are found. The temperature variation of the system under adiabatic (de)magnetization is investigated and the central role of the macroscopically degenerated ground states in cooling processes is explicitly demonstrated. It is shown that the model parameter space of the studied geometrically frustrated system is divided into five disjunct regions with qualitatively different processes of the adiabatic cooling. The effectiveness of the adiabatic (de)magnetization cooling in the studied model is compared to the corresponding processes in paramagnetic salts. It is shown that the processes of the adiabatic cooling in the antiferromagnetic frustrated systems are much more effective especially in nonzero external magnetic fields. It means that the frustrated magnetic materials with pyrochlore structure can be considered as very promising refrigerants mainly in the situations with nonzero final values of the magnetic field.

  9. A systemic approach for optimal cooling tower operation

    International Nuclear Information System (INIS)

    Cortinovis, Giorgia F.; Paiva, Jose L.; Song, Tah W.; Pinto, Jose M.

    2009-01-01

    The thermal performance of a cooling tower and its cooling water system is critical for industrial plants, and small deviations from the design conditions may cause severe instability in the operation and economics of the process. External disturbances such as variation in the thermal demand of the process or oscillations in atmospheric conditions may be suppressed in multiple ways. Nevertheless, such alternatives are hardly ever implemented in the industrial operation due to the poor coordination between the utility and process sectors. The complexity of the operation increases because of the strong interaction among the process variables. In the present work, an integrated model for the minimization of the operating costs of a cooling water system is developed. The system is composed of a cooling tower as well as a network of heat exchangers. After the model is verified, several cases are studied with the objective of determining the optimal operation. It is observed that the most important operational resources to mitigate disturbances in the thermal demand of the process are, in this order: the increase in recycle water flow rate, the increase in air flow rate and finally the forced removal of a portion of the water flow rate that enters the cooling tower with the corresponding make-up flow rate.

  10. The development of a solar residential heating and cooling system

    Science.gov (United States)

    1975-01-01

    The MSFC solar heating and cooling facility was assembled to demonstrate the engineering feasibility of utilizing solar energy for heating and cooling buildings, to provide an engineering evaluation of the total system and the key subsystems, and to investigate areas of possible improvement in design and efficiency. The basic solar heating and cooling system utilizes a flat plate solar energy collector, a large water tank for thermal energy storage, heat exchangers for space heating, and an absorption cycle air conditioner for space cooling. A complete description of all systems is given. Development activities for this test system included assembly, checkout, operation, modification, and data analysis, all of which are discussed. Selected data analyses for the first 15 weeks of testing are included, findings associated with energy storage and the energy storage system are outlined, and conclusions resulting from test findings are provided. An evaluation of the data for summer operation indicates that the current system is capable of supplying an average of 50 percent of the thermal energy required to drive the air conditioner. Preliminary evaluation of data collected for operation in the heating mode during the winter indicates that nearly 100 percent of the thermal energy required for heating can be supplied by the system.

  11. Engineering development for a small-scale recirculator experiment

    International Nuclear Information System (INIS)

    Newton, M.A.; Deadrick, F.J.; Hanks, R.L.; Hawkins, S.A.; Holm, K.A.; Kirbie, H.C.; Karpenko, V.P.; Nattrass, L.A.; Longinotti, D.B.

    1995-01-01

    Lawrence Livermore National Laboratory (LLNL) is evaluating the physics and technology of recirculating induction accelerators for heavy-ion inertial-fusion drivers. As part of this evaluation, the authors are building a small-scale recirculator to demonstrate the concept and to use as a test bed for the development of recirculator technologies. System designs have been completed and components are presently being designed and developed for the small-scale recirculator. This paper discusses results of the design and development activities that are presently being conducted to implement the small-scale recirculator experiments. An, overview of the system design is presented along with a discussion of the implications of this design on the mechanical and electrical hardware. The paper focuses primarily on discussions of the development and design of the half-lattice period hardware and the advanced solid-state modulator

  12. Energy saving potential of an indirect evaporative cooler as a pre-cooling unit for mechanical cooling systems in Iran

    Energy Technology Data Exchange (ETDEWEB)

    Delfani, Shahram; Esmaeelian, Jafar; Karami, Maryam [Department of Installation, Building and Housing Research Center (BHRC), PO Box 13145-1696, Tehran (Iran, Islamic Republic of); Pasdarshahri, Hadi [Department of Mechanical Engineering, Tarbiat Modares University, PO Box 14115-143, Tehran (Iran, Islamic Republic of)

    2010-11-15

    The performance of indirect evaporative cooling system (IEC) to pre-cool air for a conventional mechanical cooling system has been investigated for four cities of Iran. For this purpose, a combined experimental setup consisting of an IEC unit followed by a packaged unit air conditioner (PUA) was designed, constructed and tested. Two air simulators were designed and used to simulate indoor heating load and outdoor design conditions. Using of experimental data and an appropriate analytical method, the performance and energy reduction capability of combined system has been evaluated through the cooling season. The results indicate IEC can reduce cooling load up to 75% during cooling seasons. Also, 55% reduction in electrical energy consumption of PUA can be obtained. (author)

  13. Radiation detector system having heat pipe based cooling

    Science.gov (United States)

    Iwanczyk, Jan S.; Saveliev, Valeri D.; Barkan, Shaul

    2006-10-31

    A radiation detector system having a heat pipe based cooling. The radiation detector system includes a radiation detector thermally coupled to a thermo electric cooler (TEC). The TEC cools down the radiation detector, whereby heat is generated by the TEC. A heat removal device dissipates the heat generated by the TEC to surrounding environment. A heat pipe has a first end thermally coupled to the TEC to receive the heat generated by the TEC, and a second end thermally coupled to the heat removal device. The heat pipe transfers the heat generated by the TEC from the first end to the second end to be removed by the heat removal device.

  14. Environmental aspects of the district cooling system application

    International Nuclear Information System (INIS)

    Bitrakovski, Dragan

    2006-01-01

    The use of air-conditioning equipment based on CFC and HCFC fluids has a direct influence on the occurrence of the greenhouse effect and damage of the ozone layer. Besides the obligatory shift og HCF cooling fluids, the reduction of such negative influences may also be achieved by the application of the district cooling system to the air-conditioning plants in the area. The paper includes example of the application of the district system, with positive effect regarding the ozone layer protection and greenhouse effect prevention. (Author)

  15. Radiant Heating and Cooling Systems. Part one

    DEFF Research Database (Denmark)

    Kim, Kwan Woo; Olesen, Bjarne W.

    2015-01-01

    The use of radiant heating systems has several thousand years of history.1,2 The early stage of radiant system application was for heating purposes, where hot air from flue gas (cooking, fires) was circulated under floors or in walls. After the introduction of plastic piping water-based radiant...

  16. A simpler, safer, higher performance cooling system arrangement for water cooled divertors

    International Nuclear Information System (INIS)

    Carelli, M.D.; Kothmann, R.E.; Green, L.; Zhan, N.J.; Stefani, F.; Roidt, R.M.

    1994-01-01

    A cooling system arrangement is presented which is specifically designed for high heat flux water cooled divertors. The motivation behind the proposed open-quotes unichannelclose quotes configuration is to provide maximum safety; this design eliminates flow instabilities liable to occur in parallel channel designs, it eliminates total blockage, it promotes cross flow to counteract the effects of partial blockage and/or local hot spots, and it is much more tolerant to the effects of debonding between the beryllium armor and the copper substrate. Added degrees of freedom allow optimization of the design, including the possibility of operating at very high heat transfer coefficients associated with nucleate boiling, while at the same time providing ample margin against departure from nucleate boiling. Projected pressure drop, pumping power, and maximum operating temperatures are lower than for conventional parallel channel designs

  17. Wind turbine generators having wind assisted cooling systems and cooling methods

    Science.gov (United States)

    Bagepalli, Bharat [Niskayuna, NY; Barnes, Gary R [Delanson, NY; Gadre, Aniruddha D [Rexford, NY; Jansen, Patrick L [Scotia, NY; Bouchard, Jr., Charles G.; Jarczynski, Emil D [Scotia, NY; Garg, Jivtesh [Cambridge, MA

    2008-09-23

    A wind generator includes: a nacelle; a hub carried by the nacelle and including at least a pair of wind turbine blades; and an electricity producing generator including a stator and a rotor carried by the nacelle. The rotor is connected to the hub and rotatable in response to wind acting on the blades to rotate the rotor relative to the stator to generate electricity. A cooling system is carried by the nacelle and includes at least one ambient air inlet port opening through a surface of the nacelle downstream of the hub and blades, and a duct for flowing air from the inlet port in a generally upstream direction toward the hub and in cooling relation to the stator.

  18. Systems Evaluation at the Cool Energy House

    Energy Technology Data Exchange (ETDEWEB)

    Williamson, J. [Steven Winter Associates, Inc., Norwalk, CT (United States); Puttagunta, S. [Steven Winter Associates, Inc., Norwalk, CT (United States)

    2013-09-01

    Steven Winter Associates, Inc. (SWA) monitored several advanced mechanical systems within a 2012 deep energy retrofitted home in the small Orlando suburb of Windermere, FL. This report provides performance results of one of the home's heat pump water heaters (HPWH) and the whole-house dehumidifier (WHD) over a six month period. In addition to assessing the energy performance of these systems,this study sought to quantify potential comfort improvements over traditional systems. This information is applicable to researchers, designers, plumbers, and HVAC contractors. Though builders and homeowners can find useful information within this report, the corresponding case studies are a likely better reference for this audience.

  19. Systems Evaluation at the Cool Energy House

    Energy Technology Data Exchange (ETDEWEB)

    J. Williamson and S. Puttagunta

    2013-09-01

    Steven Winter Associates, Inc. (SWA) monitored several advanced mechanical systems within a 2012 deep energy retrofitted home in the small Orlando suburb of Windermere, FL. This report provides performance results of one of the home's heat pump water heaters (HPWH) and the whole-house dehumidifier (WHD) over a six month period. In addition to assessing the energy performance of these systems, this study sought to quantify potential comfort improvements over traditional systems. This information is applicable to researchers, designers, plumbers, and HVAC contractors. Though builders and homeowners can find useful information within this report, the corresponding case studies are a likely better reference for this audience.

  20. Application of a fluidized bed reactor charged with aragonite for control of alkalinity, pH and carbon dioxide in marine recirculating aquaculture systems

    Science.gov (United States)

    Paul S Wills, PhD; Pfeiffer, Timothy; Baptiste, Richard; Watten, Barnaby J.

    2016-01-01

    Control of alkalinity, dissolved carbon dioxide (dCO2), and pH are critical in marine recirculating aquaculture systems (RAS) in order to maintain health and maximize growth. A small-scale prototype aragonite sand filled fluidized bed reactor was tested under varying conditions of alkalinity and dCO2 to develop and model the response of dCO2 across the reactor. A large-scale reactor was then incorporated into an operating marine recirculating aquaculture system to observe the reactor as the system moved toward equilibrium. The relationship between alkalinity dCO2, and pH across the reactor are described by multiple regression equations. The change in dCO2 across the small-scale reactor indicated a strong likelihood that an equilibrium alkalinity would be maintained by using a fluidized bed aragonite reactor. The large-scale reactor verified this observation and established equilibrium at an alkalinity of approximately 135 mg/L as CaCO3, dCO2 of 9 mg/L, and a pH of 7.0 within 4 days that was stable during a 14 day test period. The fluidized bed aragonite reactor has the potential to simplify alkalinity and pH control, and aid in dCO2 control in RAS design and operation. Aragonite sand, purchased in bulk, is less expensive than sodium bicarbonate and could reduce overall operating production costs.

  1. The abundance and diversity of heterotrophic bacteria as a function of harvesting frequency of duckweed (Lemna minor L.) in recirculating aquaculture systems.

    Science.gov (United States)

    Ardiansyah, A; Fotedar, R

    2016-07-01

    Duckweed (Lemna minor L.) is a potential biofilter for nutrient removal and acts as a substrate for heterotrophic bacteria in recirculating aquaculture systems (RAS). Here, we determined the effects of harvesting frequency of duckweed on heterotrophic bacteria in RAS. Twelve independent RAS consisting of fish-rearing tank, biofilter tank and waste-collection tank were used to study the interactions between duckweed harvest frequencies up to 6 days and the composition, abundance and diversity of heterotrophic bacteria. After 36 days, heterotrophic bacteria in the biofilter tank were primarily Gram-negative cocci or ovoid, coccobacilli, Gram-negative bacilli and Gram-positive bacilli. Most bacterial genera were Bacillus and Pseudomonas while the least common was Acinetobacter. Duckweed harvested after every 2 days produced the highest specific growth rates (SGR) and total harvested biomass of duckweed, but harboured less abundant bacteria, whereas 6-day harvests had a higher growth index (GI) of duckweed than 2-day harvests, but caused a poor relationship between SGR and biomass harvest with the abundance and diversity of heterotrophic bacteria. Stronger correlations (R(2)  > 0·65) between duckweed SGR and biomass harvest with the heterotrophic bacteria diversity were observed at 4-day harvest frequency and the control. This study provides significant information on the interaction between the harvest frequency of duckweed and the composition, abundance and diversity of heterotrophic bacteria in recirculating aquaculture systems (RAS). Different harvest frequencies significantly influence the abundance and diversity of heterotrophic bacteria, which in turn may influence the nitrogen uptake efficiency of the system. The research is useful in improving the efficiency of removing nitrogenous metabolites in RAS directly by the duckweed and associated heterotrophic bacteria. © 2016 The Society for Applied Microbiology.

  2. Passive cooling system for liquid metal cooled nuclear reactors with backup coolant flow path

    International Nuclear Information System (INIS)

    Hunsbedt, A.; Boardman, C.E.

    1993-01-01

    A dual passive cooling system for liquid metal cooled nuclear fission reactors is described, comprising the combination of: a reactor vessel for containing a pool of liquid metal coolant with a core of heat generating fissionable fuel substantially submerged therein, a side wall of the reactor vessel forming an innermost first partition; a containment vessel substantially surrounding the reactor vessel in spaced apart relation having a side wall forming a second partition; a first baffle cylinder substantially encircling the containment vessel in spaced apart relation having an encircling wall forming a third partition; a guard vessel substantially surrounding the containment vessel and first baffle cylinder in spaced apart relation having a side wall forming a forth partition; a sliding seal at the top of the guard vessel edge to isolate the dual cooling system air streams; a second baffle cylinder substantially encircling the guard vessel in spaced part relationship having an encircling wan forming a fifth partition; a concrete silo substantially surrounding the guard vessel and the second baffle cylinder in spaced apart relation providing a sixth partition; a first fluid coolant circulating flow course open to the ambient atmosphere for circulating air coolant comprising at lent one down comer duct having an opening to the atmosphere in an upper area thereof and making fluid communication with the space between the guard vessel and the first baffle cylinder and at least one riser duct having an opening to the atmosphere in the upper area thereof and making fluid communication with the space between the first baffle cylinder and the containment vessel whereby cooling fluid air can flow from the atmosphere down through the down comer duct and space between the forth and third partitions and up through the space between the third and second partition and the riser duct then out into the atmosphere; and a second fluid coolant circulating flow

  3. Liquid Cooling System for CPU by Electroconjugate Fluid

    Directory of Open Access Journals (Sweden)

    Yasuo Sakurai

    2014-06-01

    Full Text Available The dissipated power of CPU for personal computer has been increased because the performance of personal computer becomes higher. Therefore, a liquid cooling system has been employed in some personal computers in order to improve their cooling performance. Electroconjugate fluid (ECF is one of the functional fluids. ECF has a remarkable property that a strong jet flow is generated between electrodes when a high voltage is applied to ECF through the electrodes. By using this strong jet flow, an ECF-pump with simple structure, no sliding portion, no noise, and no vibration seems to be able to be developed. And then, by the use of the ECF-pump, a new liquid cooling system by ECF seems to be realized. In this study, to realize this system, an ECF-pump is proposed and fabricated to investigate the basic characteristics of the ECF-pump experimentally. Next, by utilizing the ECF-pump, a model of a liquid cooling system by ECF is manufactured and some experiments are carried out to investigate the performance of this system. As a result, by using this system, the temperature of heat source of 50 W is kept at 60°C or less. In general, CPU is usually used at this temperature or less.

  4. Efficient energy storage in liquid desiccant cooling systems

    Energy Technology Data Exchange (ETDEWEB)

    Hublitz, Astrid

    2008-07-18

    Liquid Desiccant Cooling Systems (LDCS) are open loop sorption systems for air conditioning that use a liquid desiccant such as a concentrated salt solution to dehumidify the outside air and cool it by evaporative cooling. Thermochemical energy storage in the concentrated liquid desiccant can bridge power mismatches between demand and supply. Low-flow LDCS provide high energy storage capacities but are not a state-of-the-art technology yet. The key challenge remains the uniform distribution of the liquid desiccant on the heat and mass transfer surfaces. The present research analyzes the factors of influence on the energy storage capacity by simulation of the heat and mass transfer processes and specifies performance goals for the distribution of the process media. Consequently, a distribution device for the liquid desiccant is developed that reliably meets the performance goals. (orig.)

  5. Dry storage systems with free convection air cooling

    International Nuclear Information System (INIS)

    Kioes, S.R.

    1980-01-01

    Several design principles to remove heat from the spent fuel by free air convection are illustrated and described. The key safety considerations were felt to be: loss of coolant is impossible as the passive system uses air as a coolant; overheating is precluded because as the temperatures of the containers rises the coolant flow rate increases; mass of the storage building provides a large heat sink and therefore a rapid temperature rise is impossible; and lack of any active external support requirements makes the cooling process less likely to equipment or operator failures. An example of this type of storage already exists. The German HTGR is operated with spherical graphite fuel elements which are stored in canister and in storage cells. The concept is a double cooling system with free convection inside the cells and heat exchange via two side walls of the cell to the ambient air in the cooling ducts. Technical description of the TN 1300 cask is also presented

  6. Status of helium-cooled nuclear power systems. [Development potential

    Energy Technology Data Exchange (ETDEWEB)

    Melese-d' Hospital, G.; Simnad, M

    1977-09-01

    Helium-cooled nuclear power systems offer a great potential for electricity generation when their long-term economic, environmental, conservation and energy self-sufficiency features are examined. The high-temperature gas-cooled reactor (HTGR) has the unique capability of providing high-temperature steam for electric power and process heat uses and/or high-temperature heat for endothermic chemical reactions. A variation of the standard steam cycle HTGR is one in which the helium coolant flows directly from the core to one or more closed cycle gas turbines. The effective use of nuclear fuel resources for electric power and nuclear process heat will be greatly enhanced by the gas-cooled fast breeder reactor (GCFR) currently being developed. A GCFR using thorium in the radial blanket could generate sufficient U-233 to supply the fuel for three HTGRs, or enough plutonium from a depleted uranium blanket to fuel a breeder economy expanding at about 10% per year. The feasibility of utilizing helium to cool a fusion reactor is also discussed. The status of helium-cooled nuclear energy systems is summarized as a basis for assessing their prospects. 50 references.

  7. Experimental study on solar desiccant cooling system. 2nd Report; Taiyonetsu kudo desiccant cooling system no jikkenteki kento. 2

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, H; Funato, H [Fukuoka Institute of Technology, Fukuoka (Japan); Kuma, T [Seibu Giken Co. Ltd., Fukuoka (Japan)

    1996-10-27

    Study has been made about a desiccant cleaning system using solar heated water for regenerating the dehumidifier. A dehumidifier and evaporation coolers are combined to attain a synergistic effect in dehumidifying and cooling the air in the house. The simultaneous control of humidity and temperature, however, is quite difficult. Under the circumstances, an evaporation cooler was removed from the outdoor air intake side, to leave a humidifier alone for the control of humidity only. In addition, the length of the dehumidifier was reduced into half for saving fan driving power and for downscaling the model. With only one evaporation cooler in operation that is installed at the exhaust side, the cooling effect is diminished by half. For dealing with the situation, ultrasonic atomization is performed at the exhaust side evaporation cooler for the improvement of the air cooling effect for the next sensible heat exchanger (intake side). The return air is heated by the solar heater water (approximately 60{degree}C hot), regenerates the dehumidifier, and then exhausted. The atomization process elevates the cooling effect, and the resultant cooling effect was as high as that expected from a 2-cooler setup. The dehumidification effect, however, lowers a little. Exclusion of the atomization process will enhance the dehumidification effect, but will reduce the cooling effect as well. 3 refs., 8 figs., 3 tabs.

  8. Evaluation of feed and feeding regime on growth performance, flesh quality and fecal viscosity of Atlantic salmon ( Salmo salar L.) in recirculating aquaculture systems

    Science.gov (United States)

    Sun, Guoxiang; Liu, Ying; Li, Yong; Li, Xian; Wang, Shunkui

    2015-10-01

    The effects of different feeds and feeding regimes on growth performance, flesh quality and fecal viscosity of Atlantic salmon ( Salmo salar L.) in recirculating aquaculture systems (RAS) were investigated. Fish (initial body weight of 1677 g ± 157 g) were fed with four commercial feeds (Nosan salmon-NS, Aller gold-AG, Skretting salmon-SS and Han ye-HY) in two feeding regimes (80% and 100% satiation) for 78 d. The results showed that salmon specific growth ratio (SGR) and weight gain ratio (WGR) were significantly affected by feed type and feeding regime ( P vitamin E, hydroxyproline (HYP), liquid loss and muscle pH among all groups showed significant differences ( P important quality attributes of Atlantic salmon.

  9. Development of hybrid solar-assisted cooling/heating system

    KAUST Repository

    Huang, B.J.; Wu, J.H.; Hsu, H.Y.; Wang, J.H.

    2010-01-01

    A solar-assisted ejector cooling/heating system (SACH) was developed in this study. The SACH combines a pump-less ejector cooling system (ECS) with an inverter-type heat pump (R22) and is able to provide a stable capacity for space cooling. The ECS is driven by solar heat and is used to cool the condenser of the R22 heat pump to increase its COP and reduce the energy consumption of the compressor by regulating the rotational speed of the compressor through a control system. In a complete SACH system test run at outdoor temperature 35 °C, indoor temperature 25 °C and compressor speed 20-80 Hz, and the ECS operating at generator temperature 90 °C and condensing temperature 37 °C, the corresponding condensing temperature of the heat pump in the SACH is 24.5-42 °C, cooling capacity 1.02-2.44 kW, input power 0.20-0.98 kW, and cooling COPc 5.11-2.50. This indicates that the use of ECS in SACH can effectively reduce the condensing temperature of the heat pump by 12.6-7.3 °C and reduce the power consumption by 81.2-34.5%. The SACH can also supply heat from the heat pump. At ambient temperature from 5 °C to 35 °C, the heating COPh is in the range 2.0-3.3. © 2010 Elsevier Ltd. All rights reserved.

  10. Development of hybrid solar-assisted cooling/heating system

    KAUST Repository

    Huang, B.J.

    2010-08-01

    A solar-assisted ejector cooling/heating system (SACH) was developed in this study. The SACH combines a pump-less ejector cooling system (ECS) with an inverter-type heat pump (R22) and is able to provide a stable capacity for space cooling. The ECS is driven by solar heat and is used to cool the condenser of the R22 heat pump to increase its COP and reduce the energy consumption of the compressor by regulating the rotational speed of the compressor through a control system. In a complete SACH system test run at outdoor temperature 35 °C, indoor temperature 25 °C and compressor speed 20-80 Hz, and the ECS operating at generator temperature 90 °C and condensing temperature 37 °C, the corresponding condensing temperature of the heat pump in the SACH is 24.5-42 °C, cooling capacity 1.02-2.44 kW, input power 0.20-0.98 kW, and cooling COPc 5.11-2.50. This indicates that the use of ECS in SACH can effectively reduce the condensing temperature of the heat pump by 12.6-7.3 °C and reduce the power consumption by 81.2-34.5%. The SACH can also supply heat from the heat pump. At ambient temperature from 5 °C to 35 °C, the heating COPh is in the range 2.0-3.3. © 2010 Elsevier Ltd. All rights reserved.

  11. Kinetic model for predicting the composition of chlorinated water discharged from power plant cooling systems

    International Nuclear Information System (INIS)

    Lietzke, M.H.

    1977-01-01

    The results of applying a kinetic model to the chlorination data supplied by Commonwealth Edison on the once-through cooling system at the Quad Cities Nuclear Station provide a validation of the model. The two examples given demonstrate that the model may be applied to either once-through cooling systems or to cooling systems involving cooling towers

  12. France uses the sun to cool its wine: the Banyuls winery solar cooling system

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2003-12-01

    The engineering consultancy Tecsol was asked to design a cooling system for a winery that would limit the variations in temperature during the year. Tecsol proposed a solar system. The total investment cost amounted to nearly two million French Francs (300,000 euros), almost double the cost of a conventional air-conditioning system. However, because the solar system reduced the conventional energy needs of the warehouse by about 40%, the French Agency for Environment and Energy Management (ADEME) provided a 37% subsidy for its rational use of energy. The 'Solarclim' solar installation has three functions: it produces hot water via 693 vacuum tube collectors with a useful surface of 130 m{sup 2}. The collectors are fixed to the roof of the wine cellar, which has an angle of 15 deg. Heat from the collectors is transferred to a 1000-litre hot water storage tank; it produces chilled water using a lithium bromide absorption plant with a nominal cooling capacity of 52 kW. This is housed in the technical premises on the lowest level and is used in conjunction with a 180 kW open-circuit cooling tower on the north facade; and the third function combines air-conditioning and, when necessary, space heating. The installation has been operating for 12 years with no particular problems. The equipment is environmentally friendly. The solar heat source avoids CO{sub 2} emissions, the absorption machine does not use CFCs or HCFCs, and the system is totally silent. (UK)

  13. Use of cross-flow membrane filtration in a recirculating hydroponic system to suppress root disease in pepper caused by Pythium myriotylum.

    Science.gov (United States)

    Schuerger, Andrew C; Hammer, William

    2009-05-01

    Zoosporic pathogens in the genera Pythium and Phytophthora cause extensive root disease epiphytotics in recirculating hydroponic vegetable-production greenhouses. Zoospore cysts of Pythium myriotylum Drechsler were used to evaluate the effectiveness of cross-flow membrane filters to control pythiaceous pathogens in recirculating hydroponic systems. Four membrane filter brands (Honeycomb, Polypure, Polymate, and Absolife) were tested alone or in combination to determine which filters would effectively remove infective propagules of P. myriotylum from solutions and reduce disease incidence and severity. Zoospore cysts of P. myriotylum generally measured 8 to 10 microm, and it was hypothesized that filters with pore-sizespepper plants from root infection. Single-filter assays with Honeycomb and Polypure brands removed 85 to 95% of zoospore cysts when pore sizes were rated at 1, 5, 10, 20, or 30 microm. Single-filter assays of Polymate and Absolife brands were more effective, exhibiting apparently 100% removal of zoospore cysts from nutrient solutions on filters rated at 1 to 10 microm. However, plant bioassays with Honeycomb and Polymate single filters failed to give long-term protection of pepper plants. Double-filter assays with 1- and 0.5-microm Polymate filters significantly increased the protection of pepper plants grown in nutrient film technique systems but, eventually, root disease and plant wilt could be observed. Insect transmissions by shore flies were not factors in disease development. Scanning electron microscopy images of zoospore cysts entrapped on Polymate filters revealed zoospore cysts that were either fully encysted, partially encysted, or of unusually small size (3 microm in diameter). It was concluded that either the atypically small or pliable pleomorphic zoospore cysts were able to penetrate filter membranes that theoretically should have captured them.

  14. Cool gas micropropulsion system for cubesats

    NARCIS (Netherlands)

    Breukelen, E. van; Sanders, B.H.; Schuurbiers, C.A.H.

    2009-01-01

    CubeSats are becoming more mature and many capabilities previously associated with microsatellites and bigger platforms are coming to the CubeSat. Moreover, they are becoming available as commercial off the shelf systems with standardized interfaces. TNO Defence and Security of the Netherlands is in

  15. Solar hybrid cooling system for high-tech offices in subtropical climate - Radiant cooling by absorption refrigeration and desiccant dehumidification

    International Nuclear Information System (INIS)

    Fong, K.F.; Chow, T.T.; Lee, C.K.; Lin, Z.; Chan, L.S.

    2011-01-01

    Highlights: → A solar hybrid cooling system is proposed for high-tech offices in subtropical climate. → An integration of radiant cooling, absorption refrigeration and desiccant dehumidification. → Year-round cooling and energy performances were evaluated through dynamic simulation. → Its annual primary energy consumption was lower than conventional system up to 36.5%. → The passive chilled beams were more energy-efficient than the active chilled beams. - Abstract: A solar hybrid cooling design is proposed for high cooling load demand in hot and humid climate. For the typical building cooling load, the system can handle the zone cooling load (mainly sensible) by radiant cooling with the chilled water from absorption refrigeration, while the ventilation load (largely latent) by desiccant dehumidification. This hybrid system utilizes solar energy for driving the absorption chiller and regenerating the desiccant wheel. Since a high chilled water temperature generated from the absorption chiller is not effective to handle the required latent load, desiccant dehumidification is therefore involved. It is an integration of radiant cooling, absorption refrigeration and desiccant dehumidification, which are powered up by solar energy. In this study, the application potential of the solar hybrid cooling system was evaluated for the high-tech offices in the subtropical climate through dynamic simulation. The high-tech offices are featured with relatively high internal sensible heat gains due to the intensive office electric equipment. The key performance indicators included the solar fraction and the primary energy consumption. Comparative study was also carried out for the solar hybrid cooling system using two common types of chilled ceilings, the passive chilled beams and active chilled beams. It was found that the solar hybrid cooling system was technically feasible for the applications of relatively higher cooling load demand. The annual primary energy

  16. Device for controlling a recirculation flow in a reactor

    International Nuclear Information System (INIS)

    Shida, Toichi; Tohei, Kazushige; Hirose, Masao; Nakamura, Hideo.

    1976-01-01

    Object: To provide an emergency cut-off valve in a recirculation system in a reactor to control the recirculation at the time of turbine trip or load cut-off, thereby relieving excessive increase in heat output of fuel. Structure: A recirculation pump is driven through a recirculation pump motor by an AC generator, which is driven by a driving motor through a fluid coupling, so that reactor water passes the emergency cut-off valve and recirculation flow stop valve and then passes a jet pump into the core. At the time of turbine trip or load cut-off, the emergency cut-off valve is closed by a hydraulic circuit, whereby core flow is merely decreased by 20 to 30% in a short period of time to restrain excessive increase in heat output. (Yoshino, Y.)

  17. NGL recovery being hiked by natural-gasoline recirculation

    Energy Technology Data Exchange (ETDEWEB)

    Rivas M, M.; Bracho, J.L. [Lagoven S.A., Maracaibo (Venezuela); Murray, J.E. [Murray (James E.), Corpus Christi, TX (United States)

    1997-07-07

    Construction will be completed later this year at two compression plants operated by Lagoven, S.A., to install natural-gasoline recirculation to improve NGL recovery. The project is the result of a study of condensate-stream recirculation and absorber operations at the compression plants Tia Juana 2 (PCTJ-2) and Tia Juana 3 (PCTJ-3), offshore Lake Maracaibo in western Venezuela. The PCTJ-2 and PCTJ-3 gas compression plants have two systems: gas compression and NGL extraction. Previous analysis of the NGL extraction and fractionation processes of Lagoven determined that there are two practical and attractive alternatives for the recirculation of the condensate streams in PCTJ-2 and 3: recirculation of natural gasoline from the Ule LPG plant; recirculation of a conditioned condensate from the de-ethanizer tower of each plant. Both alternatives are discussed. Also described are fractionation capacity, and modifications for adding absorption and fractionation.

  18. BETTER DUCT SYSTEMS FOR HOME HEATING AND COOLING.

    Energy Technology Data Exchange (ETDEWEB)

    ANDREWS,J.

    2001-01-01

    This is a series of six guides intended to provide a working knowledge of residential heating and cooling duct systems, an understanding of the major issues concerning efficiency, comfort, health, and safety, and practical tips on installation and repair of duct systems. These guides are intended for use by contractors, system designers, advanced technicians, and other HVAC professionals. The first two guides are also intended to be accessible to the general reader.

  19. Mathematical Model for Direct Evaporative Space Cooling Systems ...

    African Journals Online (AJOL)

    This paper deals with the development of a simple mathematical model for experimental validation of the performance of a small evaporative cooling system in a tropical climate. It also presents the coefficient of convective heat transfer of wide range of temperatures based on existing model. Extensive experiments have ...

  20. Combined system of solar heating and cooling using heat pump

    International Nuclear Information System (INIS)

    Zakhidov, R.A.; Anarbaev, A.I.

    2014-01-01

    The heating and cooling systems of apartment buildings based on combined solar heat-pump equipment has been considered and the procedure of calculating its parameters has been worked out. A technical-economic analysis has been performed and compared with the boiler-setting version. (author)

  1. Alternativini zpusoby chlazeni budov (Alternative cooling systems for buildings)

    NARCIS (Netherlands)

    Lain, M.; Hensen, J.L.M.

    2003-01-01

    in the Czech Republic, low energy in buildings and systems usually refers to low energy consumption for heating. However in modern office buildings cooling is becoming more and more important, therefore the associated energy consumption should also be considered. This paper introduces low energy

  2. Cooling System: Automotive Mechanics Instructional Program. Block 6.

    Science.gov (United States)

    O'Brien, Ralph D.

    The last of six instructional blocks in automotive mechanics, the lessons and supportive information in the document provide a guide for teachers in planning an instructional program in the automotive cooling system at the secondary and post secondary level. The material, as organized, is a suggested sequence of instruction within each block. Each…

  3. Simulation of solar-powered absorption cooling system

    Energy Technology Data Exchange (ETDEWEB)

    Atmaca, I.; Yigit, A. [Uludag Univ., Bursa (Turkey). Dept. of Mechanical Engineering

    2003-07-01

    With developing technology and the rapid increase in world population, the demand for energy is ever increasing. Conventional energy will not be enough to meet the continuously increasing need for energy in the future. In this case, renewable energy sources will become important. Solar energy is a very important energy source because of its advantages. Instead of a compressor system, which uses electricity, an absorption cooling system, using renewable energy and kinds of waste heat energy, may be used for cooling. In this study, a solar-powered, single stage, absorption cooling system, using a water-lithium bromide solution, is simulated. A modular computer program has been developed for the absorption system to simulate various cycle configurations and solar energy parameters for Antalya, Turkey. So, the effects of hot water inlet temperatures on the coefficient of performance (COP) and the surface area of the absorption cooling components are studied. In addition, reference temperatures which are the minimum allowable hot water inlet temperatures are determined and their effect on the fraction of the total load met by non-purchased energy (FNP) and the coefficient of performance are researched. Also, the effects of the collector type and storage tank mass are investigated in detail. (author)

  4. Cooling Water System Monitoring by Means of Mossbauer Spectroscopy

    International Nuclear Information System (INIS)

    Novakova, A.A.; Pargamotnikas, S.A.; Taseva, V.; Dobbrevsky, I.; Nenov, V.; Bonev, B.

    1998-01-01

    Mossbauer spectroscopy have been applied to the analysis of corrosion sediments formed on mild steel coupons, which were placed in the different points of the Bourgas Petrochemical Plant Recilculating Cooling Water System. It was shown that the created corrosion products can successfully reflect the ambient water medium pollution to which the coupons were exposed

  5. Development of cooling and cleaning systems for enhanced gas ...

    African Journals Online (AJOL)

    In order to address these tar related problems a cleaning and cooling system has been developed in house that facilitates tar removal to acceptable levels tolerated by the internal combustion (IC) engine and meets emission standards as well. The main objective of the present work is to reduce tar level and develop control ...

  6. Performance test of solar-assisted ejector cooling system

    KAUST Repository

    Huang, Bin-Juine

    2014-03-01

    A solar-assisted ejector cooling/heating system (SACH-2k) is built and test result is reported. The solar-driven ejector cooling system (ECS) is connected in series with an inverter-type air conditioner (IAC). Several advanced technologies are developed in SACH-k2, including generator liquid level control in ECS, the ECS evaporator temperature control, and optimal control of fan power in cooling tower of ECS. From the field test results, the generator liquid level control performs quite well and keeps stable performance of ejector. The ECS evaporator temperature control also performs satisfactorily to keep ejector performance normally under low or fluctuating solar radiation. The fan power control system cooling tower performs stably and reduces the power consumption dramatically without affecting the ECS performance. The test results show that the overall system COPo including power consumptions of peripheral increases from 2.94-3.3 (IAC alone) to 4.06-4.5 (SACH-k2), about 33-43%. The highest COPo is 4.5. © 2013 Elsevier Ltd and IIR. All rights reserved.

  7. The effects of long-term 20 mg/L carbon dioxide exposure on the health and performance of Atlantic salmon Salmo salar post-smolts in water recirculation aquaculture systems

    Science.gov (United States)

    Previous research and experience has linked elevated dissolved carbon dioxide (CO2) to reduced growth performance, poor feed conversion, and a variety of health issues in farm-raised fish, including Atlantic salmon Salmo salar. Supplemental control measures in water recirculation aquaculture systems...

  8. Comparing the effects of feeding a grain- or a fish meal-based diet on water quality, waste production, and rainbow trout Oncorhynchus mykiss performance within low exchange water recirculating aquaculture systems

    Science.gov (United States)

    Feeding a fish meal-free grain-based diet (GB) was compared to feeding a fish meal-based diet (FM) relative to water quality criteria, waste production, water treatment process performance, and rainbow trout Oncorhynchus mykiss performance within six replicated water recirculating aquaculture system...

  9. A Thermal Test System for Helmet Cooling Studies

    Directory of Open Access Journals (Sweden)

    Shaun Fitzgerald

    2018-02-01

    Full Text Available One of the primary causes of discomfort to both irregular and elite cyclists is heat entrapment by a helmet resulting in overheating and excessive sweating of the head. To accurately assess the cooling effectiveness of bicycle helmets, a heated plastic thermal headform has been developed. The construction consists of a 3D-printed headform of low thermal conductivity with an internal layer of high thermal mass that is heated to a constant uniform temperature by an electrical heating element. Testing is conducted in a wind tunnel where the heater power remains constant and the resulting surface temperature distribution is directly measured by 36 K-type thermocouples embedded within the surface of the head in conjunction with a thermal imaging camera. Using this new test system, four bicycle helmets were studied in order to measure their cooling abilities and to identify ‘hot spots’ where cooling performance is poor.

  10. Reactor-core isolation cooling system with dedicated generator

    International Nuclear Information System (INIS)

    Nazareno, E.V.; Dillmann, C.W.

    1992-01-01

    This patent describes a nuclear reactor complex. It comprises a dual-phase nuclear reactor; a main turbine for converting phase-conversion energy stored by vapor into mechanical energy for driving a generator; a main generator for converting the mechanical energy into electricity; a fluid reservoir external to the reactor; a reactor core isolation cooling system with several components at least some of which require electrical power. It also comprises an auxiliary pump for pumping fluid from the reservoir into the reactor pressure vessel; an auxiliary turbine for driving the pump; control means for regulating the rotation rate of the auxiliary turbine; cooling means for cooling the control means; and an auxiliary generator coupled to the auxiliary turbine for providing at least a portion of the electrical power required by the components during a blackout condition

  11. Solar heating and cooling system installed at Leavenworth, Kansas

    Science.gov (United States)

    1980-01-01

    A solar heating and cooling is described which is designed to furnish 90 percent of the overall heating load, 70 percent of the cooling load and 100 percent of the domestic hot water load. The building has two floors with a total of 12,000 square feet gross area. The system has 120 flat-plate liquid solar panels with a net area of 2,200 square feet. Five 3 ton Arkla solar assisted absorption units provide the cooling, in conjunction with a 3,000 gallon chilled water storage tank. Two 3,000 gallon storage tanks are provided with one designated for summer use, whereas both tanks are utilized during winter.

  12. Accelerator-based cold neutron sources and their cooling system

    International Nuclear Information System (INIS)

    Inoue, Kazuhiko; Yanai, Masayoshi; Ishikawa, Yoshikazu.

    1985-01-01

    We have developed and installed two accelerator-based cold neutron sources within a electron linac at Hokkaido University and a proton synchrotoron at National Laboratory for High Energy Physics. Solid methane at 20K was adopted as the cold moderator. The methane condensing heat exchangers attached directly to the moderator chambers were cooled by helium gas, which was kept cooled in refrigerators and circulated by ventilation fans. Two cold neutron sources have operated smoothly and safely for the past several years. In this paper we describe some of the results obtained in the preliminary experiments by using a modest capacity refrigerator, the design philosophy of the cooling system for the pulsed cold neutron sources, and outline of two facilities. (author)

  13. Turbine airfoil with an internal cooling system having vortex forming turbulators

    Science.gov (United States)

    Lee, Ching-Pang

    2014-12-30

    A turbine airfoil usable in a turbine engine and having at least one cooling system is disclosed. At least a portion of the cooling system may include one or more cooling channels having a plurality of turbulators protruding from an inner surface and positioned generally nonorthogonal and nonparallel to a longitudinal axis of the airfoil cooling channel. The configuration of turbulators may create a higher internal convective cooling potential for the blade cooling passage, thereby generating a high rate of internal convective heat transfer and attendant improvement in overall cooling performance. This translates into a reduction in cooling fluid demand and better turbine performance.

  14. Primary cooling system for BWR type reactor

    International Nuclear Information System (INIS)

    Ibe, Eishi; Takahashi, Masanori; Aoki, Yasuko

    1993-01-01

    The present invention effectively uses information from a plurality of sensors in order to suppress corrosion circumstance of a nuclear reactor. That is, a predetermined general water quality factor at a predetermined position is determined as a standard index. A concentration of a water quality improver is controlled such that the index is within an aimed range. For this purpose, the entire sensor groups disposed in a primary coolant system of a nuclear reactor are divided into a plural systems of sensor groups each disposed on every different positions. Then, a predetermined sensor group (standard sensor group) is connected to a computing device and a data base so that it is always monitored for calculating and estimating the standard index. Only oxidative ingredient in water at the measuring point is noted, and a concentration distribution which agrees with an actually measured value of oxidative ingredients is extracted from data base and used as a correct concentration distribution. With such procedures, reactor water quality can be estimated accurately while compensating erroneous factors of individual sensors. Even when a new sensor is used, it is not necessary to greatly change control logic. (I.S.)

  15. Air conditioning system with supplemental ice storing and cooling capacity

    Science.gov (United States)

    Weng, Kuo-Lianq; Weng, Kuo-Liang

    1998-01-01

    The present air conditioning system with ice storing and cooling capacity can generate and store ice in its pipe assembly or in an ice storage tank particularly equipped for the system, depending on the type of the air conditioning system. The system is characterized in particular in that ice can be produced and stored in the air conditioning system whereby the time of supplying cooled air can be effectively extended with the merit that the operation cycle of the on and off of the compressor can be prolonged, extending the operation lifespan of the compressor in one aspect. In another aspect, ice production and storage in great amount can be performed in an off-peak period of the electrical power consumption and the stored ice can be utilized in the peak period of the power consumption so as to provide supplemental cooling capacity for the compressor of the air conditioning system whereby the shift of peak and off-peak power consumption can be effected with ease. The present air conditioning system can lower the installation expense for an ice-storing air conditioning system and can also be applied to an old conventional air conditioning system.

  16. Analysis of three loss-of-flow accidents in the first wall cooling system of NET/ITER

    International Nuclear Information System (INIS)

    Komen, E.M.J.; Koning, H.

    1993-05-01

    This report presents the thermal-hydraulic analysis of three Loss-of-Flow Accidents (LOFAs) in the first wall cooling system of the Next European Torus (NET) design or the International Thermonuclear Experimental Reactor (ITER) design. The LOFAs considered result from a loss of the forced coolant flow caused by a loss of electrical power for the recirculation pump in the primary circuit. The analyses have been performed using the thermal-hydraulic system analysis code RELAP5/MOD3. In the analyses, special attention has been paid to the transient thermal-hydraulic behaviour of the cooling system and the temperature development in the first wall. In the LOFA case without plasma shutdown, melting starts in the first wall about 150 s after accident initiation. In the LOFA case with delayed plasma shutdown, melting starts in the first wall when the plasma shutdown is initiated later than about 110 s after accident initiation. Melting does not occur in the first wall during a LOFA with prompt plasma scram. (orig.)

  17. Experimental Studies of NGNP Reactor Cavity Cooling System With Water

    Energy Technology Data Exchange (ETDEWEB)

    Corradini, Michael; Anderson, Mark; Hassan, Yassin; Tokuhiro, Akira

    2013-01-16

    This project will investigate the flow behavior that can occur in the reactor cavity cooling system (RCCS) with water coolant under the passive cooling-mode of operation. The team will conduct separate-effects tests and develop associated scaling analyses, and provide system-level phenomenological and computational models that describe key flow phenomena during RCCS operation, from forced to natural circulation, single-phase flow and two-phase flow and flashing. The project consists of the following tasks: Task 1. Conduct separate-effects, single-phase flow experiments and develop scaling analyses for comparison to system-level computational modeling for the RCCS standpipe design. A transition from forced to natural convection cooling occurs in the standpipe under accident conditions. These tests will measure global flow behavior and local flow velocities, as well as develop instrumentation for use in larger scale tests, thereby providing proper flow distribution among standpipes for decay heat removal. Task 2. Conduct separate-effects experiments for the RCCS standpipe design as two-phase flashing occurs and flow develops. As natural circulation cooling continues without an ultimate heat sink, water within the system will heat to temperatures approaching saturation , at which point two-phase flashing and flow will begin. The focus is to develop a phenomenological model from these tests that will describe the flashing and flow stability phenomena. In addition, one could determine the efficiency of phase separation in the RCCS storage tank as the two-phase flashing phenomena ensues and the storage tank vents the steam produced. Task 3. Develop a system-level computational model that will describe the overall RCCS behavior as it transitions from forced flow to natural circulation and eventual two-phase flow in the passive cooling-mode of operation. This modeling can then be used to test the phenomenological models developed as a function of scale.

  18. Investigation on flow stability of supercritical water cooled systems

    International Nuclear Information System (INIS)

    Cheng, X.; Kuang, B.

    2006-01-01

    Research activities are ongoing worldwide to develop nuclear power plants with supercritical water cooled reactor (SCWR) with the purpose to achieve a high thermal efficiency and to improve their economical competitiveness. However, the strong variation of the thermal-physical properties of water in the vicinity of the pseudo-critical line results in challenging tasks in various fields, e.g. thermal-hydraulic design of a SCWR. One of the challenging tasks is to understand and to predict the dynamic behavior of supercritical water cooled systems. Although many thermal-hydraulic research activities were carried out worldwide in the past as well as in the near present, studies on dynamic behavior and flow stability of SC water cooled systems are scare. Due to the strong density variation, flow stability is expected to be one of the key items which need to be taken into account in the design of a SCWR. In the present work, the dynamic behavior and flow stability of SC water cooled systems are investigated using both numerical and theoretical approaches. For this purpose a new computer code SASC was developed, which can be applied to analysis the dynamic behavior of systems cooled by supercritical fluids. In addition, based on the assumptions of a simplified system, a theoretical model was derived for the prediction of the onset of flow instability. A comparison was made between the results obtained using the theoretical model and those from the SASC code. A good agreement was achieved. This gives the first evidence of the reliability of both the SASC code and the theoretical model

  19. The integration of cryogenic cooling systems with superconducting electronic systems

    International Nuclear Information System (INIS)

    Green, Michael A.

    2003-01-01

    The need for cryogenic cooling has been critical issue that has kept superconducting electronic devices from reaching the market place. Even though the performance of the superconducting circuit is superior to silicon electronics, the requirement for cryogenic cooling has put the superconducting devices at a disadvantage. This report will talk about the various methods for refrigerating superconducting devices. Cryocooler types will be compared for vibration, efficiency, and cost. Some solutions to specific problems of integrating cryocoolers to superconducting devices are presented.

  20. Benchmark ultra-cool dwarfs in widely separated binary systems

    Directory of Open Access Journals (Sweden)

    Jones H.R.A.

    2011-07-01

    Full Text Available Ultra-cool dwarfs as wide companions to subgiants, giants, white dwarfs and main sequence stars can be very good benchmark objects, for which we can infer physical properties with minimal reference to theoretical models, through association with the primary stars. We have searched for benchmark ultra-cool dwarfs in widely separated binary systems using SDSS, UKIDSS, and 2MASS. We then estimate spectral types using SDSS spectroscopy and multi-band colors, place constraints on distance, and perform proper motions calculations for all candidates which have sufficient epoch baseline coverage. Analysis of the proper motion and distance constraints show that eight of our ultra-cool dwarfs are members of widely separated binary systems. Another L3.5 dwarf, SDSS 0832, is shown to be a companion to the bright K3 giant η Cancri. Such primaries can provide age and metallicity constraints for any companion objects, yielding excellent benchmark objects. This is the first wide ultra-cool dwarf + giant binary system identified.

  1. CFD Model Development and validation for High Temperature Gas Cooled Reactor Cavity Cooling System (RCCS) Applications

    International Nuclear Information System (INIS)

    Hassan, Yassin; Corradini, Michael; Tokuhiro, Akira; Wei, Thomas Y.C.

    2014-01-01

    The Reactor Cavity Cooling Systems (RCCS) is a passive safety system that will be incorporated in the VTHR design. The system was designed to remove the heat from the reactor cavity and maintain the temperature of structures and concrete walls under desired limits during normal operation (steady-state) and accident scenarios. A small scale (1:23) water-cooled experimental facility was scaled, designed, and constructed in order to study the complex thermohydraulic phenomena taking place in the RCCS during steady-state and transient conditions. The facility represents a portion of the reactor vessel with nine stainless steel coolant risers and utilizes water as coolant. The facility was equipped with instrumentation to measure temperatures and flow rates and a general verification was completed during the shakedown. A model of the experimental facility was prepared using RELAP5-3D and simulations were performed to validate the scaling procedure. The experimental data produced during the steady-state run were compared with the simulation results obtained using RELAP5-3D. The overall behavior of the facility met the expectations. The facility capabilities were confirmed to be very promising in performing additional experimental tests, including flow visualization, and produce data for code validation.

  2. CFD Model Development and validation for High Temperature Gas Cooled Reactor Cavity Cooling System (RCCS) Applications

    Energy Technology Data Exchange (ETDEWEB)

    Hassan, Yassin [Univ. of Wisconsin, Madison, WI (United Texas A & M Univ., College Station, TX (United States); Corradini, Michael; Tokuhiro, Akira; Wei, Thomas Y.C.

    2014-07-14

    The Reactor Cavity Cooling Systems (RCCS) is a passive safety system that will be incorporated in the VTHR design. The system was designed to remove the heat from the reactor cavity and maintain the temperature of structures and concrete walls under desired limits during normal operation (steady-state) and accident scenarios. A small scale (1:23) water-cooled experimental facility was scaled, designed, and constructed in order to study the complex thermohydraulic phenomena taking place in the RCCS during steady-state and transient conditions. The facility represents a portion of the reactor vessel with nine stainless steel coolant risers and utilizes water as coolant. The facility was equipped with instrumentation to measure temperatures and flow rates and a general verification was completed during the shakedown. A model of the experimental facility was prepared using RELAP5-3D and simulations were performed to validate the scaling procedure. The experimental data produced during the steady-state run were compared with the simulation results obtained using RELAP5-3D. The overall behavior of the facility met the expectations. The facility capabilities were confirmed to be very promising in performing additional experimental tests, including flow visualization, and produce data for code validation.

  3. Energy management techniques: SRP cooling water distribution system

    International Nuclear Information System (INIS)

    Edenfield, A.B.

    1979-10-01

    Cooling water for the nuclear reactors at the Savannah River Plant is supplied by a pumping and distribution system that includes about 50 miles of underground pipeline. The energy management program at SRP has thus far achieved a savings of about 5% (186 x 10 9 Btu) of the energy consumed by the electrically powered cooling water pumps; additional savings of about 14% (535 x 10 9 Btu) can be achieved by capital expenditures totaling about $3.7 million. The present cost of electricity for operation of this system is about $25 million per year. A computer model of the system was adapted and field test data were used to normalize the program to accurately represent pipeline physical characteristics. Alternate pumping schemes are analyzed to determine projected energy costs and impact on system safety and reliability

  4. What can go wrong in stochastic cooling systems

    CERN Document Server

    AUTHOR|(CDS)2108502

    2016-01-01

    This paper discusses very practical aspects of stochastic cooling systems both during construction, running-in, operation and trouble shooting. Due to the high electronic gain, high sensitivity and large bandwidth of such systems, precautions have to be taken to avoid all sorts of EMI/EMC related problems as well as crosstalk and self-oscillations. Since un-intended beam heating is always much more efficient than the desired cooling the overall performance depends critically on avoiding this heating which often takes places outside the nominal frequency band of operation. Another important aspect is “cross heating”, i.e., unavoidable crosstalk from longitudinal to transverse systems and vice versa. Obviously adequate measurement procedures with beam for gain phase and optimum delay are mandatory and certain caveats and hints are given. The paper concludes with a listing of unusual and unexpected problems found during many years of operation of such systems at CERN.

  5. Preliminary Study of Solar Chimney Assisted Cooling System for SMART

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Byung Il; Park, Seong Jun; Lee, Young Hyeon; Park, Hyo Chan; Park, Youn Won [BEES Inc., KAIST, Daejeon (Korea, Republic of)

    2016-05-15

    In this paper, the possibility of application for a complete passive final heat removal system using a solar chimney power plant for SMART NPP was estimated. Additionally the size of the cooling system was approximately calculated under the some assumptions. In order to estimate the applicability of SCPP as a complete passive secondary cooling system for SMART, we try to calculate the size of heat exchanger and simulate SCPP performance. As a result, it was found that SCPP could be coupled with SMART and some of waste heat could be recovered into electricity without any change in SCPP size. The related all parameters satisfying the constraint of the final heat removal system for SMART were calculated. Using the constraint of the amount of heat to be removed from SMART, two kinds of SCPP performances were analyzed; one for a stand alone SCPP in Fig 8(a) and second for SCPP with SMART in Fig 8(b)

  6. Thermophysical fundamentals of cyclonic recirculating heating devices

    Science.gov (United States)

    Karpov, S. V.; Zagoskin, A. A.

    2017-10-01

    This report presents the results of experimental and theoretical research of aerodynamics and convective heat transfer in cyclone devices with the new system of external recirculation of heating gas under the influence of radial pressure gradient in a heat carrier’s swirling turbulent flow. The dynamic problem of tangential velocity distribution in a clearance volume is solved at various re-circulation ratio values including limiting quantities (kr = 0; 1) and variations in cyclonic combustion chamber’s design parameters and operating conditions (Rer); the integrated calculation ratios for fundamental aerodynamic characteristics of a recirculation device are derived. The first experimental and numerical studies of convective heat transfer on internal and external surfaces of a hollow shaft in a swirling recirculation flow are derived through the instrumentality of OpenFOAM, these studies are also conducted for a setting of several cylindrical solid inserts. The external surface heat problem of a hollow cylindrical insert is solved with integral and digital methods; generalized similarity equations for the internal and external surfaces extended in range of Reynolds number are derived. The experimental data is in reasonable agreement with the derived curves and the results of mathematic modelling of convective heat transfer. Calculation recommendations for optimal selection of kr values at various ratios of their geometric characteristics and products utilization rate are obtained.

  7. Alkali Metal Backup Cooling for Stirling Systems - Experimental Results

    Science.gov (United States)

    Schwendeman, Carl; Tarau, Calin; Anderson, William G.; Cornell, Peggy A.

    2013-01-01

    In a Stirling Radioisotope Power System (RPS), heat must be continuously removed from the General Purpose Heat Source (GPHS) modules to maintain the modules and surrounding insulation at acceptable temperatures. The Stirling convertor normally provides this cooling. If the Stirling convertor stops in the current system, the insulation is designed to spoil, preventing damage to the GPHS at the cost of an early termination of the mission. An alkali-metal Variable Conductance Heat Pipe (VCHP) can be used to passively allow multiple stops and restarts of the Stirling convertor. In a previous NASA SBIR Program, Advanced Cooling Technologies, Inc. (ACT) developed a series of sodium VCHPs as backup cooling systems for Stirling RPS. The operation of these VCHPs was demonstrated using Stirling heater head simulators and GPHS simulators. In the most recent effort, a sodium VCHP with a stainless steel envelope was designed, fabricated and tested at NASA Glenn Research Center (GRC) with a Stirling convertor for two concepts; one for the Advanced Stirling Radioisotope Generator (ASRG) back up cooling system and one for the Long-lived Venus Lander thermal management system. The VCHP is designed to activate and remove heat from the stopped convertor at a 19 degC temperature increase from the nominal vapor temperature. The 19 degC temperature increase from nominal is low enough to avoid risking standard ASRG operation and spoiling of the Multi-Layer Insulation (MLI). In addition, the same backup cooling system can be applied to the Stirling convertor used for the refrigeration system of the Long-lived Venus Lander. The VCHP will allow the refrigeration system to: 1) rest during transit at a lower temperature than nominal; 2) pre-cool the modules to an even lower temperature before the entry in Venus atmosphere; 3) work at nominal temperature on Venus surface; 4) briefly stop multiple times on the Venus surface to allow scientific measurements. This paper presents the experimental

  8. Cooling the intact loop of primary heat transport system using shut down cooling system after events such as LOCA

    International Nuclear Information System (INIS)

    Icleanu, D.L.

    2015-01-01

    The purpose of this paper is to model the Shutdown Cooling System operation for CANDU 6 NPP in case of LOCA accident, using Flowmaster calculation code by delimiting models and setting calculation assumptions and input data for hydraulic analysis, and and assumptions for the calculation and input data for calculating thermal performance check heat exchangers that are part of this system. The Flowmaster V7.8 code provides system engineers with a powerful tool to investigate pressure surge, pressure drop, flow rate, temperature and system response times - removing the uncertainty from fluid flow systems. Flowmaster is a one-dimensional thermal-hydraulic calculation code for dimensioning, analyzing and verifying the pipeline systems operation. Each component of Flowmaster is a mathematical model for an equipment that is included in a facility. Selected components are connected via nodes in order to form a network, which constitutes a computerized model of the system. Analyzing the parameters of the cooling system for all cooling processes considered it was found that the values obtained for thermal-hydraulic parameters, as well as the duration up to reaching specified limits fall within the design values of the system. This document is made up of an abstract and the slides of the presentation

  9. Comparative analysis of thermally activated, environmentally friendly cooling systems

    International Nuclear Information System (INIS)

    Gupta, Y.; Metchop, L.; Frantzis, A.; Phelan, P.E.

    2008-01-01

    This paper compares the relative performances of three different thermally activated, environmentally friendly cooling systems, e.g. a silica-gel-water adsorption system, a LiBr-H 2 O absorption system and a desiccant air system. The adsorption and absorption systems in the current study employ water as the refrigerant, while the desiccant system cools atmospheric air directly. Each of these systems can be utilized at relatively low heat source temperatures such as achieved by flat plate solar collectors, but it is unclear which of these systems is best suited to what range of heat source temperature. Our study explores answers to this question by generating quantitative results comparing their relative thermal performance, i.e. COP and refrigeration capacity, and a qualitative comparison based on the size, maturity of technology, safe operation etc. In order to provide a fair comparison between the fundamentally different systems, a UA (overall heat transfer coefficient multiplied by the heat transfer area) value of 1.0 kW deg. C -1 is considered for the heat exchanger that transfers heat from the supplied hot water. Furthermore, to compare systems of similar size, the mass of silica-gel in the adsorption and desiccant systems and the mass of LiBr-H 2 O solution in the absorption system were specified such that each system provides the same amount of refrigeration (8.0 kW) at a source temperature of 90 deg. C. It is found that the absorption and adsorption cooling systems have a higher refrigeration capacity at heat source temperatures below 90 deg. C, while the desiccant air system outperforms the others at temperatures above 90 deg. C

  10. Ten questions about radiant heating and cooling systems

    DEFF Research Database (Denmark)

    Rhee, Kyu-Nam; Olesen, Bjarne W.; Kim, Kwang Woo

    2017-01-01

    studies on RHC systems in terms of comfort, heat transfer analysis, energy simulation, control strategy, system configurations and so on. Many studies have demonstrated that the RHC system is a good solution to improve indoor environmental quality while reducing building energy consumption for heating......Radiant heating and cooling (RHC) systems are being increasingly applied not only in residential but also in non-residential buildings such as commercial buildings, education facilities, and even large scale buildings such as airport terminals. Furthermore, with the combined ventilation system used...

  11. Structural optimization of a microjet based cooling system for high power LEDs

    Energy Technology Data Exchange (ETDEWEB)

    Sheng Liu; Zhiyin Gan [Institute for Microsystems, School of Mechanical Engineering, Huazhong University of Science and Technology, Wuhan (China); Wuhan National Lab of Optoelectronics, Huazhong University of Science and Technology, Wuhan (China); Jianghui Yang [School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan (China); Xiaobing Luo [Wuhan National Lab of Optoelectronics, Huazhong University of Science and Technology, Wuhan (China); School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan (China)

    2008-08-15

    Based on the previous experiments and simulations reported by the present authors, it was found the cooling system could be optimized to obtain better performance. In this paper, the microjet cooling systems with three different microjet structures were numerically investigated. The numerical model was proven by the experiments. The optimization results demonstrate that the microjet structure with one single inlet but two outlets can achieve better cooling performance. The simulation results show that the maximum temperature of the LED substrate cooled by the optimized microjet cooling device was 23 K lower than that of the LED substrate cooled by the present experimental cooling system. (author)

  12. Operational aspects of the VELO cooling system of LHCb

    CERN Document Server

    Jans, E

    2014-01-01

    The VELO is a silicon strip detector that is positioned around the interaction region of LHCb. It is placed inside a secondary vacuum with respect to that of the LHC. The cooling system of the VELO is based on the bi-phase accumulator controlled method, using CO$_2$ as coolant. The main objective is the removal of the heat produced by the front-end electronics. Moreover, the leakage currents of the sensors are strongly reduced and thermal runaway is prevented. Since the sensors have been irradiated in Run 1 they should always be cooled to below $^-$5 $^{\\rm{o}}$C. The operational principle and main characteristics of the system are described, as well as the warning and safety systems that guarantee the safe operation of the detector. The few problems that have been encountered during the four years of continuous operation are discussed together with the solutions that have been implemented.

  13. Balancing passive and active systems for evolutionary water cooled reactors

    International Nuclear Information System (INIS)

    Fil, N.S.; Allen, P.J.; Kirmse, R.E.; Kurihara, M.; Oh, S.J.; Sinha, R.K.

    1999-01-01

    Advanced concepts of the water-cooled reactors are intended to improve safety, economics and public perception of nuclear power. The potential inclusion of new passive means in addition or instead of traditional active systems is being considered by nuclear plant designers to reach these goals. With respect to plant safety, application of the passive means is mainly intended to simplify the safety systems and to improve their reliability, to mitigate the effect of human errors and equipment malfunction. However, some clear drawbacks and the limited experience and testing of passive systems may raise additional questions that have to be addressed in the design process for each advanced reactor. Therefore the plant designer should find a reasonable balance of active and passive means to effectively use their advantages and compensate their drawbacks. Some considerations that have to be taken into account when balancing active/passive means in advanced water-cooled reactors are discussed in this paper. (author)

  14. Heat pipe as a cooling mechanism in an aeroponic system

    Energy Technology Data Exchange (ETDEWEB)

    Srihajong, N.; Terdtoon, P.; Kamonpet, P. [Department of Mechanical Engineering, Faculty of Engineering, Chiang Mai University, Chiang Mai 50200 (Thailand); Ruamrungsri, S. [Department of Horticulture, Faculty of Agriculture, Chiang Mai University, Chiang Mai 50200 (Thailand); Ohyama, T. [Department of Applied Biological Chemistry, Faculty of Agriculture, Niigata University (Japan)

    2006-02-01

    This paper presents an establishment of a mathematical model explaining the operation of an aeroponic system for agricultural products. The purpose is to study the rate of energy consumption in a conventional aeroponic system and the feasibility of employing a heat pipe as an energy saver in such a system. A heat pipe can be theoretically employed to remove heat from the liquid nutrient that flows through the growing chamber of an aeroponic system. When the evaporator of the heat pipe receives heat from the nutrient, the inside working fluid evaporates into vapor and flows to condense at the condenser section. The outlet temperature of the nutrient from the evaporator section is, therefore, decreased by the heat removal mechanism. The heat pipe can also be used to remove heat from the greenhouse by applying it on the greenhouse wall. By doing this, the nutrient temperature before entering into the nutrient tank decreases and the cooling load of evaporative cooling will subsequently be decreased. To justify the heat pipe application as an energy saver, numerical computations have been done on typical days in the month of April from which maximum heating load occurs and an appropriate heat pipe set was theoretically designed. It can be seen from the simulation that the heat pipe can reduce the electric energy consumption of an evaporative cooling and a refrigeration systems in a day by 17.19% and 10.34% respectively. (author)

  15. Design of SMART waste heat removal dry cooling tower using solar energy

    International Nuclear Information System (INIS)

    Choi, Yong Jae; Jeong, Yong Hoon

    2014-01-01

    The 85% of cooling system are once-through cooling system and closed cycle wet cooling system. However, many countries are trying to reduce the power plant water requirement due to the water shortage and water pollution. Dry cooling system is investigated for water saving advantage. There are two dry cooling system which are direct and indirect cooling system. In direct type, turbine exhaust is directly cooled by air-cooled condenser. In indirect system, turbine steam is cooled by recirculating intermediate cooling water loop, then the loop is cooled by air-cooled heat exchanger in cooling tower. In this paper, the purpose is to remove SMART waste heat, 200MW by using newly designed tower. The possibility of enhancing cooling performance by solar energy is analyzed. The simple cooling tower and solar energy cooling tower are presented and two design should meet the purpose of removing SMART waste heat, 200MW. In first design, when tower diameter is 70m, the height of tower should be 360m high. In second design, the chimney height decrease from 360m to 180m as collector radius increase from 100m to 500m due to collector temperature enhancement by solar energy, To analyze solar cooling tower further, consideration of solar energy performance at night should be analyzed

  16. Design of SMART waste heat removal dry cooling tower using solar energy

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Yong Jae; Jeong, Yong Hoon [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    2014-10-15

    The 85% of cooling system are once-through cooling system and closed cycle wet cooling system. However, many countries are trying to reduce the power plant water requirement due to the water shortage and water pollution. Dry cooling system is investigated for water saving advantage. There are two dry cooling system which are direct and indirect cooling system. In direct type, turbine exhaust is directly cooled by air-cooled condenser. In indirect system, turbine steam is cooled by recirculating intermediate cooling water loop, then the loop is cooled by air-cooled heat exchanger in cooling tower. In this paper, the purpose is to remove SMART waste heat, 200MW by using newly designed tower. The possibility of enhancing cooling performance by solar energy is analyzed. The simple cooling tower and solar energy cooling tower are presented and two design should meet the purpose of removing SMART waste heat, 200MW. In first design, when tower diameter is 70m, the height of tower should be 360m high. In second design, the chimney height decrease from 360m to 180m as collector radius increase from 100m to 500m due to collector temperature enhancement by solar energy, To analyze solar cooling tower further, consideration of solar energy performance at night should be analyzed.

  17. Gas-cooled reactor power systems for space

    International Nuclear Information System (INIS)

    Walter, C.E.

    1987-01-01

    Efficiency and mass characteristics for four gas-cooled reactor power system configurations in the 2- to 20-MWe power range are modeled. The configurations use direct and indirect Brayton cycles with and without regeneration in the power conversion loop. The prismatic ceramic core of the reactor consists of several thousand pencil-shaped tubes made from a homogeneous mixture of moderator and fuel. The heat rejection system is found to be the major contributor to system mass, particularly at high power levels. A direct, regenerated Brayton cycle with helium working fluid permits high efficiency and low specific mass for a 10-MWe system

  18. Convective Performance of Nanofluids in Commercial Electronics Cooling Systems

    International Nuclear Information System (INIS)

    Roberts, N.A.; Walker, D.G.

    2010-01-01

    Nanofluids are stable engineered colloidal suspensions of a small fraction of nanoparticles in a base fluid. Nanofluids have shown great promise as heat transfer fluids over typically used base fluids and fluids with micron sized particles. Suspensions with micron sized particles are known to settle rapidly and cause clogging and damage to the surfaces of pumping and flow equipment. These problems are dramatically reduced in nanofluids. In the current work we investigate the performance of different volume loadings of water-based alumina nanofluids in a commercially available electronics cooling system. The commercially available system is a water block used for liquid cooling of a computational processing unit. The size of the nanoparticles in the study is 20-30 nm. Results show an enhancement in convective heat transfer due to the addition of nanoparticles in the commercial cooling system with volume loadings of nanoparticles up to 1.5% by volume. The enhancement in the convective performance observed is similar to what has been reported in well controlled and understood systems and is commensurate with bulk models. The current nanoparticle suspensions showed visible signs of settling which varied from hours to weeks depending on the size of the particles used.

  19. The cool seal system: a practical solution to the shaft seal problem and heat related complications with implantable rotary blood pumps.

    Science.gov (United States)

    Yamazaki, K; Mori, T; Tomioka, J; Litwak, P; Antaki, J F; Tagusari, O; Koyanagi, H; Griffith, B P; Kormos, R L

    1997-01-01

    A critical issue facing the development of an implantable, rotary blood pump is the maintenance of an effective seal at the rotating shaft. Mechanical seals are the most versatile type of seal in wide industrial applications. However, in a rotary blood pump, typical seal life is much shorter than required for chronic support. Seal failure is related to adhesion and aggregation of heat denatured blood proteins that diffuse into the lubricating film between seal faces. Among the blood proteins, fibrinogen plays an important role due to its strong propensity for adhesion and low transition temperature (approximately 50 degrees C). Once exposed to temperature exceeding 50 degrees C, fibrinogen molecules fuse together by multi-attachment between heat denatured D-domains. This quasi-polymerized fibrin increases the frictional heat, which proliferates the process into seal failure. If the temperature of the seal faces is maintained well below 50 degrees C, a mechanical seal would not fail in blood. Based on this "Cool-Seal" concept, we developed a miniature mechanical seal made of highly thermally conductive material (SiC), combined with a recirculating purge system. A large supply of purge fluid is recirculated behind the seal face to augment convective heat transfer to maintain the seal temperature below 40 degrees C. It also cools all heat generating pump parts (motor coil, bearing, seal). The purge consumption has been optimized to virtually nil (seal system has now been incorporated into our intraventricular axial flow blood pump (IVAP) and newly designed centrifugal pump. Ongoing in vivo evaluation of these systems has demonstrated good seal integrity for more than 160 days. The Cool-Seal system can be applied to any type of rotary blood pump (axial, diagonal, centrifugal, etc.) and offers a practical solution to the shaft seal problem and heat related complications, which currently limit the use of implantable rotary blood pumps.

  20. Analysis and simulation of mobile air conditioning system coupled with engine cooling system

    International Nuclear Information System (INIS)

    Qi, Zhao-gang; Chen, Jiang-ping; Chen, Zhi-jiu

    2007-01-01

    Many components of the mobile air conditioning system and engine cooling system are closely interrelated and make up the vehicle climate control system. In the present paper, a vehicle climate control system model including air conditioning system and engine cooling system has been proposed under different operational conditions. All the components have been modeled on the basis of experimental data. Based on the commercial software, a computer simulation procedure of the vehicle climate control system has been developed. The performance of the vehicle climate control system is simulated, and the calculational data have good agreement with experimental data. Furthermore, the vehicle climate control simulation results have been compared with an individual air conditioning system and engine cooling system. The influences between the mobile air conditioning system and the engine cooling system are discussed