The Oriented Spray Cooling System for Heat Rejection and Evaporation

2019 ◽  
Author(s):  
Charles F. Bowman ◽  
Robert E. Taylor ◽  
Jerry D. Hubble
Keyword(s):  
Thermal Performance ◽  
Cooling System ◽  
Air Flow ◽  
Ambient Air ◽  
Nuclear Regulatory Commission ◽  
Spray Cooling ◽  
Analytical Models ◽  
Water Droplets ◽  
Flow Through ◽  
Regulatory Commission

Abstract Spray ponds offer significant advantages over mechanical draft cooling towers (MDCT) including superior simplicity and operability, lower preferred power requirements, and lower capital and maintenance costs. Unlike a conventional spray pond in which spray nozzles are arranged in a flat bed and water is sprayed upward, the Oriented Spray Cooling System (OSCS) is an evolutionary spray pond design in which nozzles are mounted on spray trees arranged in a circle and are tilted at an angle oriented towards the center of the circle. As a result, each nozzle is exposed to essentially ambient air as water droplets drag air into the spray region while the warm air concentrated in the center of the circle rises. Both of these effects work together to increase air flow through the spray region. Increased air flow reduces the local wet-bulb temperature (LWBT) of the air in the spray pattern, promoting heat transfer and more efficient cooling. The authors have developed analytical models to predict the thermal performance of the OSCS that are based on classical heat and mass transfer and kinetic vector relationships for spherical water droplets that rely only on generic experimental thermal performance data. Therefore, the model is not limited in application with regard to spray pressure or nozzle spacing or orientation and is not limited by droplet size considerations. This paper describes specific details such as nozzle type, orientation, and drop spectrum and details on the analytical model never before published that are used to predict the OSCS performance. The paper compares the predicted performance of the OSCS with the rigorous full-scale field test results that were measured in compliance with Nuclear Regulatory Commission requirements at the Columbia Generating Station (CGS) where the ultimate heat sink (UHS) is two OSCS.

The Oriented Spray Cooling System for Heat Rejection and Evaporation

2021 ◽  
Author(s):  
Chuck Bowman ◽  
Robert E. Taylor ◽  
Jerry D. Hubble
Keyword(s):  
Thermal Performance ◽  
Cooling System ◽  
Air Flow ◽  
Ambient Air ◽  
Nuclear Regulatory Commission ◽  
Spray Cooling ◽  
Analytical Models ◽  
Water Droplets ◽  
Flow Through ◽  
Regulatory Commission

Abstract Spray ponds offer significant advantages over mechanical draft cooling towers including superior simplicity and operability, lower preferred power requirements, and lower costs. Unlike a conventional spray pond in which spray nozzles are arranged in a flat bed and water is sprayed upward, the Oriented Spray Cooling System (OSCS) is an evolutionary spray pond design in which nozzles are mounted on spray trees arranged in a circle and are tilted at an angle oriented towards the center of the circle. Therefore, each nozzle is exposed to essentially ambient air as water droplets drag air into the spray region while the warm air concentrated in the center of the circle rises. Both of these effects work together to increase air flow through the spray region. Increased air flow reduces the local wet-bulb temperature of the air in the spray pattern, promoting heat transfer and more efficient cooling. The authors have developed analytical models to predict the thermal performance of the OSCS that are based on classical heat and mass transfer and kinetic vector relationships for spherical water droplets that rely only on generic experimental thermal performance data. The model is not limited in application with regard to spray pressure or nozzle spacing or orientation and is not limited by droplet size considerations. The paper compares the predicted performance of the OSCS with full-scale field test results that were measured in compliance with Nuclear Regulatory Commission requirements at the Columbia Generating Station where the ultimate heat sink is two OSCS.

The Oriented Spray Cooling System for Supplementing Cooling Lakes

2017 ◽  
Author(s):  
Charles F. Bowman
Keyword(s):  
Power Plants ◽  
Waste Heat ◽  
Cooling System ◽  
Air Flow ◽  
Ambient Air ◽  
Spray Cooling ◽  
Cooling Capacity ◽  
Ambient Temperatures ◽  
Circulating Water ◽  
Auxiliary Power

With ever-increasing ambient temperatures many electric power plants that employ cooling lakes to reject their waste heat into the environment are struggling to maintain reasonable turbine backpressures during the hot summer months when electric load demand is often the greatest. Some consider adding mechanical draft cooling towers (MDCT) to further cool the condenser circulating water (CCW) prior to entering the main condenser, but the additional auxiliary power required to drive MDCT fans often consume the additional generator output resulting from the lower backpressure. Spray ponds offer significant advantages over MDCT including superior simplicity and operability, lower power requirements, and lower capital and maintenance costs. The Oriented Spray Cooling System (OSCS) is an evolutionary spray pond design. Unlike a conventional spray pond in which spray nozzles are arranged in a flat bed and spray upward, blocking the ambient air flow to the spray region as it travels down to the pond below, the OSCS nozzles are mounted on spray trees arranged in a circle and are tilted at an angle oriented towards the center of the circle. As a result, the water droplets drag air into the spray region while the warm air concentrated in the center of the circle rises. Both of these effects work together to increase air flow through the spray region. Increased air flow reduces the local wet-bulb temperature (LWBT) of the air in the spray pattern, promoting heat transfer and more efficient cooling. During the late 1970’s the author developed a purely analytical model to predict the thermal performance of the OSCS which was successfully compared with the OSCS at the Columbia Generating Station (CGS) in the mid 1980’s. This paper describes how the OSCS may be employed to supplement the cooling capacity of an existing cooling lake to reduce the temperature of the CCW prior to entering a power plant, resulting in lower main condenser pressures and more net plant output.

Spray Cooling for Time Resolved Emission Measurements of ICs

2004 ◽  
Author(s):  
Rama R. Goruganthu ◽  
David Bethke ◽  
Shawn McBride ◽  
Tom Crawford ◽  
Jonathan Frank ◽  
...  
Keyword(s):  
Heat Flux ◽  
Thermal Performance ◽  
Flip Chip ◽  
Cooling System ◽  
Spray Cooling ◽  
Junction Temperature ◽  
Maximum Temperature ◽  
Uniform Heat Flux ◽  
High Heat Flux ◽  
Time Resolved

Abstract Spray cooling is implemented on an engineering tool for Time Resolved Emission measurements using a silicon solid immersion lens to achieve high spatial resolution and for probing high heat flux devices. Thermal performance is characterized using a thermal test vehicle consisting of a 4x3 array of cells each with a heater element and a thermal diode to monitor the temperature within the cell. The flip-chip packaged TTV is operated to achieve uniform heat flux across the die. The temperature distribution across the die is measured on the 4x3 grid of the die for various heat loads up to 180 W with corresponding heat flux of 204 W/cm2. Using water as coolant the maximum temperature differential across the die was about 30 °C while keeping the maximum junction temperature below 95 °C and at a heat flux of 200 W/cm2. Details of the thermal performance of spray cooling system as a function of flow rate, coolant

A gas-atomized spray cooling system integrated with an ejector loop: Ejector modeling and thermal performance analysis

2019 ◽  
Vol 180 ◽  
pp. 106-118 ◽  
Author(s):  
Ji-Xiang Wang ◽  
Yun-Ze Li ◽  
Jia-Xin Li ◽  
Chao Li ◽  
Yi Zhang ◽  
...  
Keyword(s):  
Performance Analysis ◽  
Thermal Performance ◽  
Cooling System ◽  
Spray Cooling

scholarly journals CFD analysis of air flow through the LNG ambient air vaporizer with longitudinal finned tubes

2021 ◽  
Vol 323 ◽  
pp. 00021
Author(s):  
Filip Lisowski ◽  
Edward Lisowski
Keyword(s):  
Air Flow ◽  
Ambient Air ◽  
Finned Tube ◽  
The Other ◽  
Wind Pressure ◽  
Cfd Analysis ◽  
Finned Tubes ◽  
Wind Velocities ◽  
Flow Through ◽  
Forced Air

Ambient air vaporizers, depending on their efficiency, can be up to several meters high. Therefore, they can have a large outside surface area exposed to the wind. Forced air flow through the vaporizer structure have a beneficial effect on improving heat transfer from the environment. On the other hand, if the vaporizer is placed in the region of significant wind velocities, the wind forces acting on the structure can be considerable. This paper presents CFD analysis of air flow through the structure of the ambient air vaporizer with a 6 x 6 finned tube array. The effect of changing wind direction on the wind pressure and wind velocity distributions is investigated.

Effect of Fan Speed on Air Flow Through a Green Wall Module

2018 ◽  
Author(s):  
Peter Abdo ◽  
B. P. Huynh ◽  
Vahik Avakian
Keyword(s):  
Cooling System ◽  
Air Flow ◽  
Flow Distribution ◽  
Active Systems ◽  
System A ◽  
Particulate Pollutants ◽  
Back Face ◽  
Flow Through ◽  
Fan Speed ◽  
Wall System

Green or living walls are active bio-filters developed to enhance air quality. Often, these walls form the base from which plants are grown; and the plant-wall system helps to remove both gaseous and particulate air pollutants. They can be classified as passive or active systems. The active systems are designed with ventilators which force air through the substrate and plant rooting system, therefore the air is purified and filtered through a bio-filtration process which also acts as a natural cooling system. A fan positioned at a central opening on the module’s back face drives air through the medium-plant-roots mix and then onward through the plants’ canopy; and these would help to remove both gaseous and particulate pollutants from the air. Pressure drop across the module, air flow distribution through it as well as the total flow rate have been obtained. The effect of different fan speeds on the total air flow and on its distribution through the module is investigated in this study in order to optimize the energy consumption of the fans whilst maintaining the modules biofiltration efficiency.

The Effect of Chamber Pressure on the Thermal Performance of New Refrigerant R513a During Spray Cooling

2019 ◽  
Author(s):  
Nabeel M. Abdulrazzaq ◽  
Azzam S. Salman ◽  
Noble Anumbe ◽  
Amitav Tikadar ◽  
Saad K. Oudah ◽  
...  
Keyword(s):  
Thermal Performance ◽  
Closed Loop ◽  
Cooling System ◽  
Heated Surface ◽  
Saturation Temperature ◽  
Spray Cooling ◽  
Copper Surface ◽  
Chamber Pressure ◽  
Refrigeration System ◽  
Spray Chamber

Abstract In this paper, the performance of a new low-GWP refrigerant R513a was experimentally investigated, during spray cooling. A spray cooling system was designed to work as a sub-system within a closed-loop refrigeration system. The influence of chamber pressure on heat flux and heat transfer coefficient were experimentally investigated. A smooth plain copper surface heated by a cartridge heater was cooled by the refrigerant (R513a) while flowing through a nozzle in the spray chamber. The results showed that chamber pressure has a significant impact on the overall thermal performance of the spray cooling operation. It was also determined that higher chamber pressures resulted in higher thermal performance. The highest chamber pressure attained in this study was 0.6 MPa. Furthermore, the surface temperature of the heated surface increased due to the increase of the saturation temperature of the liquid over the surface.

Decommissioning the Georgia Tech Research Reactor

2001 ◽  
Author(s):  
Robert Eby ◽  
Lark Lundberg ◽  
Steve Marske ◽  
Nolan Hertel ◽  
Rod Ice
Keyword(s):  
Nuclear Reactor ◽  
Research Reactor ◽  
Cooling System ◽  
Cooling Water ◽  
Nuclear Regulatory Commission ◽  
Georgia Tech ◽  
Spent Fuel ◽  
Survey Report ◽  
Institute Of Technology ◽  
Regulatory Commission

Abstract The Georgia Tech Research Reactor (GTRR) is a 5-megawatt (MW) heavy-water-cooled nuclear reactor located on the Georgia Institute of Technology (Georgia Tech) campus in downtown Atlanta, Georgia. On July 1, 1997, Georgia Tech administration notified the U.S. Nuclear Regulatory Commission (NRC) of their intent to decommission the GTRR. In the summer of 1999, the NRC issued a license amendment to decommission the GTRR in accordance with NRC’s Regulatory Guide 1.86. In the spring of 1999, Georgia Tech and the State of Georgia contracted CH2M HILL to serve as the Executive Engineer to manage the decommissioning project. Later in the summer of 1999, the IT Corporation was selected as the Decommissioning Contractor. The Decommissioning Contractor began the dismantlement process at the Georgia Tech site in November, 1999. By February, 2000, reactor support systems such as the primary and secondary cooling water systems, and the bismuth cooling system were removed and packaged for off-site disposal. Reactor internals were removed in April, 2000. Removal of the bioshield occurred from May through November, 2000. Throughout January, 2001, various concrete structures, including the Spent Fuel Storage Hole, were decontaminated. Dismantlement and decontamination activities were completed by April, 2001. The Final Survey Report to the NRC is planned to be submitted to the NRC December, 2001, 2001. Final license termination by the NRC is anticipated in the spring of 2002.

Heat Exchange Effectiveness and Pressure Drop for Air Flow Through Perforated Plates With and Without Crosswind

1994 ◽  
Vol 116 (2) ◽  
pp. 391-399 ◽  
Author(s):  
C. F. Kutscher
Keyword(s):  
Heat Transfer ◽  
Heat Exchange ◽  
Pressure Drop ◽  
Air Flow ◽  
Ambient Air ◽  
Perforated Plates ◽  
Wind Speeds ◽  
New Type ◽  
Flow Through ◽  
Heat Exchange Effectiveness

Low-porosity perforated plates are being used as absorbers for heating ambient air in a new type of unglazed solar collector. This paper investigates the convective heat transfer effectiveness for low-speed air flow through thin, isothermal perforated plates with and without a crosswind on the upstream face. The objective of this work is to provide information that will allow designers to optimize hole size and spacing. In order to obtain performance data, a wind tunnel and small lamp array were designed and built. Experimental data were taken for a range of plate porosities from 0.1 to 5 percent, hole Reynolds numbers from 100 to 2000, and wind speeds from 0 to 4 m/s. Correlations were developed for heat exchange effectiveness and also for pressure drop. Infrared thermography was used to visualize the heat transfer taking place at the surface.

scholarly journals Development Considerations of AREVA NP Inc.'s Realistic LBLOCA Analysis Methodology

2008 ◽  
Vol 2008 ◽  
pp. 1-13 ◽  
Author(s):  
Robert P. Martin ◽  
Larry D. O'Dell
Keyword(s):  
Cooling System ◽  
Nuclear Regulatory Commission ◽  
The United States ◽  
Lessons Learned ◽  
Technical Program ◽  
Methodology Development ◽  
Analysis Methodology ◽  
Loss Of Coolant Accident ◽  
Core Cooling ◽  
Regulatory Commission

The AREVA NP Inc. realistic large-break loss-of-coolant-accident (LOCA) analysis methodology references the 1988 amended 10 CFR 50.46 allowing best-estimate calculations of emergency core cooling system performance. This methodology conforms to the code scaling, applicability, and uncertainty (CSAU) methodology developed by the Technical Program Group for the United States Nuclear Regulatory Commission in the late 1980s. In addition, several practical considerations were revealed with the move to a production application. This paper describes the methodology development within the CSAU framework and utility objectives, lessons learned, and insight about current LOCA issues.

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