Mathematical Model for Spray Cooling Systems

1977 ◽  
Vol 99 (2) ◽  
pp. 279-283 ◽  
Author(s):  
H. A. Frediani ◽  
N. Smith
Keyword(s):  
Mathematical Model ◽  
Large Scale ◽  
Cooling System ◽  
Spray Cooling ◽  
System Model ◽  
Cellular Model ◽  
Cooling Systems ◽  
Cellular Analysis ◽  
Finite Difference Solution ◽  
Energy Equations

A mathematical model of a large-scale spray cooling system is described. The continuity and energy equations are developed for a cellular model representing a single spray in a system of sprays. The equations are solved using a finite-difference solution along a drop trajectory for both water and air parameters. The results of the cellular analysis are incorporated into a system model in which the interaction between sprays for both the water and air is considered. The model was used to simulate existing systems employing multiple rows of sprays, and the results of the calculations compare well with the available data.

scholarly journals Energy-focused substantiation of the choice of an air conditioning system for an office and shopping building

2021 ◽  
Vol 11 (2) ◽  
pp. 38-45
Author(s):  
Anastasiya A. Frolova ◽  
◽  
Pavel I. Lukhmenev ◽  
Keyword(s):  
Power Consumption ◽  
Air Conditioning ◽  
Large Scale ◽  
Cooling System ◽  
Air Cooling ◽  
Outdoor Temperature ◽  
Cooling Systems ◽  
Air Conditioning System ◽  
Northern Areas ◽  
Conventional Cooling

Introduction. The air conditioning system is the main consumer of electricity inside office and shopping buildings. The coo­ling needs arise inside such buildings all over the year due to high amounts of heat emitted by people and equipment (computers, office equipment, cash registers), solar radiation (the envelopes of the majority of these buildings have continuous glazed facades) and sources of artificial lighting. A conventional cooling system has a compressor and condensers. The most important step towards an optimized and low-energy cooling system is the abandonment of compressor and condensers; in addition, the cold extracted from the outdoor air, is used in the system. This cooling technique is called an atmospheric co­oling system. The climatic features of Russia allow for a large-scale application of the cooling technology that uses natural cold. However, for a start, a decision was made to focus on a central region of the Russian Federation, namely, Moscow, rather than any northern areas of the country. Materials and methods. The problem is solved by the calculation method applied to the case of a 35-storey office building in Moscow. Various outdoor temperature options were considered as the bases for a transition to an atmospheric cooling system. The co-authors also compare different installation options for dry coolers, which in turn affect the routing length of refrigeration circuits. The annual demand for cold is calculated for all analyzed options. Results. Some results are presented in the form of tables of annual energy consumption by different types of air cooling systems. Conclusions. The co-authors have found that the location of dry coolers strongly affects the power consumption by a co­oling system. Power consumption by cooling systems was analyzed, and it was found out that transition to machine refrigeration at the higher outdoor temperature of +8 °C is more efficient from the standpoint of energy efficiency than the same transition at +5 and 0 °C.

Numerical Simulation of Accident Spray Cooling System in FGD System Inlet

2014 ◽  
Vol 703 ◽  
pp. 237-240
Author(s):  
Dian Xun Li ◽  
Shu Sheng Zhang
Keyword(s):  
Numerical Simulation ◽  
High Temperature ◽  
Power Plant ◽  
Flue Gas ◽  
Cooling System ◽  
Spray Cooling ◽  
Sprinkler System ◽  
System Model ◽  
Water Spray

By accident of a power plant desulfurization CFD Research sprinkler system model to simulate the process of considering the two-way coupling between the droplet atomization, evaporation, with the main flue gas stream. The results showed that x = 3300 sectional arrangement 40 nozzles, high temperature flue gas through a water spray after 10.8m reach x = 14100 section of the temperature has dropped to 358K, before entering the GGH down to 345K, meet an accident situation spray cooling requirements.

Air-Vapor Dynamics in Large-Scale Atmospheric Spray Cooling Systems

1978 ◽  
Vol 100 (1) ◽  
pp. 65-72 ◽  
Author(s):  
Sushil Chaturvedi ◽  
R. W. Porter
Keyword(s):  
Reasonable Agreement ◽  
Large Scale ◽  
Spray Cooling ◽  
Cooling Towers ◽  
Cooling Systems ◽  
Flow Through ◽  
Spray Field ◽  
Large Flow ◽  
Essential Problem ◽  
Theory And Experiments

Atmospheric spray cooling systems are alternatives to cooling towers and cooling ponds. A quantity NTU containing the spray drop-wise parameters allows prediction of cooling range if local wet-bulb temperature is known. The essential problem is predicting local wet-bulb proceeding windward through the spray field. Theory was developed for this purpose involving wind attenuation and turbulent diffusion. Experiments were performed on a large flow-through spray canal involving segments with two types of floating spray modules. Previous experimental data are available for a fixed manifolded spray pond. A comparison of theory and experiments shows reasonable agreement.

Use of Engineered Materials to Reduce Both Strainer Head Loss and Fiber Bypass for Emergency Core Cooling Systems

2019 ◽  
Author(s):  
Alan J. Bilanin ◽  
Andrew E. Kaufman ◽  
Warren J. Bilanin
Keyword(s):  
Large Scale ◽  
Cooling System ◽  
Head Loss ◽  
Small Scale ◽  
Pressurized Water ◽  
Cooling Systems ◽  
Large Scale Testing ◽  
Engineered Materials ◽  
Water Reactors ◽  
Core Cooling

Abstract Testing has shown that the use of engineered materials that can be combined with Loss of Cooling Accident generated debris has the ability to reduce debris head loss for boiling water and pressurized water reactors on Emergency Core Cooling System strainers. This engineered material has also been shown to reduce the amount of fiber that penetrates a strainer and continues downstream toward the fuel. Large scale testing is described that demonstrates that engineered materials can reach the strainers and reduce head loss. Small scale testing is described that demonstrates that engineered material can reduce the amount of fiber that can penetrate a strainer.

Unit Thermal Performance of Atmospheric Spray Cooling Systems

1980 ◽  
Vol 102 (2) ◽  
pp. 210-214 ◽  
Author(s):  
R. W. Porter ◽  
M. Jain ◽  
S. K. Chaturvedi
Keyword(s):  
Thermal Performance ◽  
Large Scale ◽  
Field Experiments ◽  
Characteristic Length ◽  
Local Heating ◽  
Spray Cooling ◽  
Sauter Mean Diameter ◽  
Cooling Systems ◽  
Group Number ◽  
Good Agreement

Thermal performance of an open atmospheric spray pond or canal depends on the direct-contact evaporative cooling of an individual spray unit (spray nozzle or module) and the interference caused by local heating and humidification. Droplet parameters may be combined into a dimensionless group, number of transfer units (NTU) or equivalent, whereas large-scale air-vapor dynamics determine interference through the local wet-bulb temperature. Quantity NTU were implied from field experiments for a floating module used in steam-condenser spray canals. Previous data were available for a fixed-pipe nozzle assembly used in spray ponds. Quantity NTU were also predicted using the Ranz-Marshall correlations with the Sauter-mean diameter used as the characteristic length. Good agreement with experiments was shown for diameters of 1–1.1 cm (module) and 1.9 mm (fixed-pipe nozzle).

scholarly journals Modelica-Based Modeling and Simulation of District Cooling Systems: A Case Study

2021 ◽  
Author(s):  
Kathryn Hinkelman ◽  
Jing Wang ◽  
Wangda Zuo ◽  
Antoine Gautier ◽  
Michael Wetter ◽  
...  
Keyword(s):  
Carbon Dioxide Emissions ◽  
Large Scale ◽  
Cooling System ◽  
Object Oriented ◽  
College Campus ◽  
Cooling Systems ◽  
Source Models ◽  
Electricity Costs ◽  
And Control

While equation-based object-oriented modeling language Modelica can evaluate practical energy improvements for district cooling systems, few have adapted Modelica for this type of large-scale thermo-fluid system. Further, to our best knowledge, district cooling modeling studies have yet to include hydraulics in piping network nor waterside economizers. These are critical details to include when looking to make energy and control improvements in many physical system installations. To fi?ll these gaps, this study applies newly developed open-source models from the Modelica Buildings library. For a real-world case study, we modeled and simulated a district cooling system at a college campus in Colorado, United States, with six buildings connected to a central chiller plant featuring a waterside economizer. Several energy saving strategies are pursued based on the validated model, including control setpoint optimization, equipment modification, and pump setpoint adjustments. Results indicate that optimizing the condenser water supply temperature setpoint can save 2.5% to 4.4% energy; the nonintegrated waterside economizer saves 6.4% energy while cutting down the chillers' run times by 201 days/year, reducing maintenance costs, and extending chiller life; and adjusting the condenser water pump flow settings can save 10.2% energy. Through a combinationof the studied measures, the campus can annually save 84.6 MWh of energy, 8.9% of electricity costs, and 58.0 metric tons of carbon dioxide emissions. Further, the numerical results of simulating districts from tens to hundreds of buildings are presented.

scholarly journals Improving the cooling systems of automotive engines and methods for monitoring their condition

2021 ◽  
pp. 41-44
Author(s):  
E.P. Parlyuk ◽  
Keyword(s):  
Mathematical Model ◽  
Heat Exchanger ◽  
Heat Dissipation ◽  
Cooling System ◽  
Quantitative Relationship ◽  
Thermal Processes ◽  
Structural Diagram ◽  
Cooling Systems ◽  
Automotive Engines ◽  
Machine Operation

It has been established that the cooling system of modern tractors and trucks can include 5 to 7 independent cooling circuits. A structural diagram of a modular cooling system for automotive engines and a mathematical model of thermal processes in a heat exchanger of the modular cooling system during machine operation are proposed. It is shown that the development of an algorithm for predicting and monitoring the state of the modular cooling system is possible based on a quantitative relationship between the rate of decrease in heat dissipation capacity and the duration of machine operation.

Development of the Simulation Software for Secondary Cooling Heat Transfer in Beam Blank Continuous Casting Process Based on FLUENT

2012 ◽  
Vol 538-541 ◽  
pp. 2071-2076 ◽  
Author(s):  
Qiang Liu ◽  
Wei Feng Xue ◽  
Jian Wu Yan ◽  
Deng Fu Chen ◽  
Jian Feng Ma
Keyword(s):  
Heat Transfer ◽  
Mathematical Model ◽  
Continuous Casting ◽  
Cooling System ◽  
Casting Process ◽  
Spray Cooling ◽  
Simulation Software ◽  
Secondary Development ◽  
Secondary Cooling ◽  
Heat Transfer Simulation

A 2D mathematical Model for heat transfer during solidification in the secondary cooling was established on researching the process of beam blank continuous casting. Meanwhile, the boundary conditions of heat transfer was subdivided into four parts, which is the radiation, spray cooling, heat conduction through roller and water accumulated evaporation in secondary cooling zoon, and improved the results accuracy. Moreover, heat transfer simulation software was designed and developed by a 2D mathematical Model based on FLUENT. The secondary development language UDF (User Define Function) and Scheme (a dialect of LISP) of FLUENT were used during the development. The software provided a platform for researching on the solidification and optimization of a secondary cooling system for a caster machine of beam blank.

scholarly journals Estimation of multi-layer coating efficiency for passive radiative cooling

2021 ◽  
Vol 5 (2) ◽  
pp. 37-46
Author(s):  
S. S. Jenblat ◽  
◽  
O. V. Volkova ◽  
Keyword(s):  
Mathematical Model ◽  
Optical Properties ◽  
Cooling System ◽  
Climatic Conditions ◽  
Cooling Power ◽  
Radiative Cooling ◽  
Cooling Systems ◽  
Coating Efficiency ◽  
Atmospheric Transmittance ◽  
Layer Coating

Passive radiative cooling is a promising direction in energy conservation and environmental protection. One of the ways to increase the efficiency of radiative cooling systems is the use of multi-layer coatings. In recent years, several novel materials with high emissivity have been proposed, which allow the creation of radiators that provide an average daily cooling power of approximately 100 W/m2 during daytime. Based on the developed mathematical model, the optical properties of the multi-layer coating for the radiative cooling system were evaluated by the Transfer Matrix Method and the effectiveness of radiative cooling was determined due to the use of the multi-layer coating in the climatic conditions of Syria (Latakia). The results of modeling the atmospheric transmittance in the summer months in Syria (Latakia) are presented. The developed mathematical model, methods for modeling atmospheric transmittance, calculating solar radiation, and evaluating the optical properties of multi-layer coating, allow determining an effective multi-layer coating for radiative cooling systems in any climatic conditions

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