The Outside Transport Phenomena of the Passive Containment Cooling System

2013 ◽  
Author(s):  
Cheng Li ◽  
Huanran Fan ◽  
Ruichang Zhao
Keyword(s):  
Mathematical Model ◽  
Driving Forces ◽  
Cooling System ◽  
Flow Direction ◽  
Transport Phenomena ◽  
Water Film ◽  
Heat Fluxes ◽  
Steady Condition ◽  
Air Circulation ◽  
Velocity Water

Based on the outside cooling of the Passive Containment Cooling System (PCCS), a simplified containment mathematical model was built and was numerically solved. Air circulation driven by natural forces for a steady condition along with the coupled thermal-hydraulic phenomena was then obtained and analyzed. Variations of humid air temperature and velocity, water film sub-cooling and heat fluxes along the flow direction were discussed and driving forces were compared to obtain the ranked important phenomena of the PCCS outside cooling. The conclusions are significant to reasonably understand the PCCS outside transport phenomena.

scholarly journals Numerical analysis of heat transfer in air-water heat exchanger with microchannel coil

2019 ◽  
Vol 95 ◽  
pp. 02004
Author(s):  
Vladimir Glazar ◽  
Anica Trp ◽  
Kristian Lenic ◽  
Fran Torbarina
Keyword(s):  
Heat Transfer ◽  
Mathematical Model ◽  
Fluid Flow ◽  
Heat Exchanger ◽  
Numerical Analysis ◽  
Flow Direction ◽  
Heat Fluxes ◽  
Experimental Investigations ◽  
Flow And Heat Transfer ◽  
Working Parameters

This paper presents numerical analysis of fluid flow and heat transfer in the heat exchanger with microchannel coil (MCHX). In accordance with previously published experimental results, 3D mathematical model has been defined and appropriate numerical simulation of heat transfer has been performed. Geometry and working parameters of cross-flow air-water heat exchanger with microchannel coil, installed in an open circuit wind tunnel and used in experimental investigations, have been applied in numerical analysis in order to validate the mathematical model. 3D model with air and water fluid flow and heat transfer domains has been used, as it gives more precise results compared to models that assume constant temperatures or constant heat fluxes on the pipe walls. Developed model comprised full length of air and water flows in the heat exchanger. Due to limitations of computational capacity, domain has been divided in multiple computational blocks in the water flow direction and then solved successively using CFD solver Fluent. Good agreement between experimentally measured and numerically calculated results has been obtained. The influence of various working parameters on heat transfer in air-water heat exchanger has been studied numerically, followed with discussion and final conclusions.

A simplified method of temperature control maximizing productivity of the batch reactor; The effect of inertia of the cooling system

1982 ◽  
Vol 47 (2) ◽  
pp. 454-464 ◽  
Author(s):  
František Jiráček ◽  
Josef Horák
Keyword(s):  
Mathematical Model ◽  
Temperature Control ◽  
Cooling System ◽  
Batch Reactor ◽  
Exothermic Reaction ◽  
Cooling Capacity ◽  
Variable Activity ◽  
Simplified Method ◽  
Opening And Closing ◽  
Time Of Operation

The effect has been studied of the inertia of the cooling system on the reliability of control of the temperature of the reaction mixture. The study has been made using a mathematical model of the batch reactor with an exothermic reaction. The temperature has been controlled by a two-level controller opening and closing the flow of the coolant. The aim of the control has been to maintain a constant value of the degree of utilization of the cooling capacity of the reactor. The instantaneous value of the degree of utilization has been assessed from the ratio of times for which the cooling system is idle to the time of operation. The reliability of control has been studied for variable activity of the catalyst.

scholarly journals Air circulation in a gastrointestinal light source box and endoscope in the era of SARS-CoV-2 and airborne transmission of microorganisms

2021 ◽  
Vol 09 (03) ◽  
pp. E482-E486
Author(s):  
Stanislas Chaussade ◽  
Einas Abou Ali ◽  
Rachel Hallit ◽  
Arthur Belle ◽  
Maximilien Barret ◽  
...  
Keyword(s):  
Light Source ◽  
Cooling System ◽  
Air Cooling ◽  
Airborne Transmission ◽  
Plastic Tube ◽  
Care Workers ◽  
Air Cooling System ◽  
Forced Air ◽  
Air Circulation ◽  
Closed Environment

Abstract Background and study aims The role that air circulation through a gastrointestinal endoscopy system plays in airborne transmission of microorganisms has never been investigated. The aim of this study was to explore the potential risk of transmission and potential improvements in the system. Methods We investigated and described air circulation into gastrointestinal endoscopes from Fujifilm, Olympus, and Pentax. Results The light source box contains a lamp, either Xenon or LED. The temperature of the light is high and is regulated by a forced-air cooling system to maintain a stable temperature in the middle of the box. The air used by the forced-air cooling system is sucked from the closed environment of the patient through an aeration port, located close to the light source and evacuated out of the box by one or two ventilators. No filter exists to avoid dispersion of particles outside the processor box. The light source box also contains an insufflation air pump. The air is sucked from the light source box through one or two holes in the air pump and pushed from the air pump into the air pipe of the endoscope through a plastic tube. Because the air pump does not have a dedicated HEPA filter, transmission of microorganisms cannot be excluded. Conclusions Changes are necessary to prevent airborne transmission. Exclusive use of an external CO2 pump and wrapping the endoscope platform with a plastic film will limit scatter of microorganisms. In the era of pandemic virus with airborne transmission, improvements in gastrointestinal ventilation systems are necessary to avoid contamination of patients and health care workers.

scholarly journals Analysis of a Mathematical Model for Drilling System With Reverse Air Circulation by Using the ANN-BHCS Technique

IEEE Access ◽  
2021 ◽  
Vol 9 ◽  
pp. 119188-119218
Author(s):  
Ashfaq Ahmad ◽  
Muhammad Sulaiman ◽  
Poom Kumam ◽  
Maharani Abu Bakar ◽  
Miftahuddin
Keyword(s):  
Mathematical Model ◽  
Drilling System ◽  
Air Circulation

Dynamic Analysis on a Cable-Driven Interventional Active Catheter Using Kane's Method Combined with Screw Theory

2014 ◽  
Vol 527 ◽  
pp. 140-145
Author(s):  
Da Xu Zhao ◽  
Bai Chen ◽  
Guo Zhong Shou ◽  
Yu Qi Gu
Keyword(s):  
Mathematical Model ◽  
Dynamic Analysis ◽  
Motion Control ◽  
Screw Theory ◽  
Driving Forces ◽  
Structure Design ◽  
Kinematics And Dynamics ◽  
Existing Problems ◽  
Blind Area ◽  
The Mathematical Model

In view of the existing problems of traditional interventional catheters, particularly poor activity, operation difficulty and mass blind area, a novel interventional catheter with a cable-driven active head-end is proposed, and a prototype was built to verify the performance. This paper deals with the kinematics and dynamics of the cable-driven prototype, a dynamic model based on Kanes method combined with screw theory was presented in this paper. According the mathematical model and the prototypes structure, the analysis of kinematics and dynamics of active head-end-end is done in the environment of Mathematica. The needed driving forces of every joint when the system moving along planned trajectory are calculated. The results can provide a basis for the structure design and motion control of the interventional active catheter.

scholarly journals CALCULATION OF TEMPERATURE OF ROUTINE WATER COOLED IN IRRIGATED LAYERS

2019 ◽  
Vol 2019 (3) ◽  
pp. 249-255
Author(s):  
N Usmonov ◽  
◽  
Sh Sanayev ◽  
Z Yusupov
Keyword(s):  
Mathematical Model ◽  
Cooling System ◽  
Material Balance ◽  
Polymeric Materials ◽  
Water Supply Systems ◽  
Evaporative Water ◽  
Circulating Water ◽  
Industrial Enterprises ◽  
Air Cooler ◽  
Air Conditioning Systems

The article describes the developed mathematical model, algorithm and program for calculating the process of cooling the water leaving the evaporative cooler and the final temperature of humid air. The compilation of a mathematical model is based on the analysis of literature data. Practically at all industrial enterprises, technological equipment is cooled by means of circulating water supply systems equipped with evaporative coolers. The article made a choice of a cooling system for air conditioning systems of residential premises. The developed basic design scheme of the evaporative water and air cooler with the irrigated layer is presented, as well as the estimated thermal and material balance. One of the main elements of these devices is a heat-mass transfer nozzle - sprinkler. This article presents the results of mathematical modeling of processes occurring in the volume of the sprinkler evaporator chamber, Raschig rings composed of vertical polymeric materials. Expressions are obtained for determining the values of air temperature based on the calculation of thermal modeling of the process of cooling circulating water in evaporative coolers of the type in question.

scholarly journals Application of Ultrasonic Atomization in a Combined Circulation System of Spray Evaporative Cooling and Air Cooling for Electric Machines

Processes ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 1773
Author(s):  
Yu Wang ◽  
Lin Ruan
Keyword(s):  
Cooling System ◽  
Evaporative Cooling ◽  
Convection Heat Transfer ◽  
Cooling Capacity ◽  
Circulation System ◽  
Air Cooling ◽  
Test Model ◽  
Ultrasonic Atomization ◽  
System A ◽  
Air Circulation

A combined circulation system of spray evaporative cooling and air cooling (CCSSECAC) is a way to enhance the cooling performance of an air-cooled electric machine while maintaining its existing structure. Based on a traditional air-cooled machine, when the discrete evaporative cooling medium particles are scattered into the airflow, they will reach the heat source with the air circulation. The cooling capacity of the cooling system is enhanced simultaneously through the phase transition and convection heat transfer. Ultrasonic atomization is a simple way to produce tiny droplets and a good way to improve the performance of CCSSECAC. To verify the effectiveness of such a system, a principle test model was built and a multi-operational condition experiment was carried out as an exploratory study. The experimental results showed that the new cooling system was feasible for horizontal machines, and the stator coil temperature was significantly reduced compared with the air-cooled mode.

The Study of Deformability of Heat-Resistant Alloy Named “Inconel Alloy 625” for Estimation of Plates Production Possibility at Wide-Strip Rolling “Mill 2300”

2019 ◽  
Vol 946 ◽  
pp. 818-822 ◽  
Author(s):  
Nikita S. Deryabin
Keyword(s):  
Mathematical Model ◽  
Rolling Mill ◽  
Cooling System ◽  
Rolling Process ◽  
Inconel 625 ◽  
Technological Parameters ◽  
Strip Rolling ◽  
Cracking Behavior ◽  
Inconel Alloy ◽  
Alloy 625

The hot deformation behavior of the Inconel alloy 625 was investigated through compression test within the temperature range of 850–1250 °C and the strain rate range of 0.1–30 s−1. Physically based mathematical model involving dynamic recovery and dynamic recrystallization processes has been proposed. Mathematical model allowed to calculate technological parameters of a rolling process of the “Inconel 625” at the hot rolling mill 2300. The pilot rolling operations showed that the possibility of the “Inconel 625” production exists. But it is necessary to provide the design changes of the cooling system of the work rolls. The article addressed the cracking behavior of nickel alloys in industries such as chemical process, nuclear generation, aircraft engine production.

Review and Projections of Integrated Cooling Systems for Three-Dimensional Integrated Circuits

2014 ◽  
Vol 136 (2) ◽  
Author(s):  
Satish G. Kandlikar
Keyword(s):  
Hot Spots ◽  
Heat Dissipation ◽  
Cooling System ◽  
Mechanical Design ◽  
Heat Fluxes ◽  
Electrical Performance ◽  
Channel Height ◽  
Cooling Systems ◽  
3D Ic ◽  
Pressure Drops

In an effort to increase processor speeds, 3D IC architecture is being aggressively pursued by researchers and chip manufacturers. This architecture allows extremely high level of integration with enhanced electrical performance and expanded functionality, and facilitates realization of VLSI and ULSI technologies. However, utilizing the third dimension to provide additional device layers poses thermal challenges due to the increased heat dissipation and complex electrical interconnects among different layers. The conflicting needs of the cooling system requiring larger flow passage dimensions to limit the pressure drop, and the IC architecture necessitating short interconnect distances to reduce signal latency warrant paradigm shifts in both of their design approach. Additional considerations include the effects due to temperature nonuniformity, localized hot spots, complex fluidic connections, and mechanical design. This paper reviews the advances in 3D IC cooling in the last decade and provides a vision for codesigning 3D IC architecture and integrated cooling systems. For heat fluxes of 50–100 W/cm2 on each side of a chip in a 3D IC package, the current single-phase cooling technology is projected to provide adequate cooling, albeit with high pressure drops. For future applications with coolant surface heat fluxes from 100 to 500 W/cm2, significant changes need to be made in both electrical and cooling technologies through a new level of codesign. Effectively mitigating the high temperatures surrounding local hot spots remains a challenging issue. The codesign approach with circuit, software and thermal designers working together is seen as essential. The through silicon vias (TSVs) in the current designs place a stringent limit on the channel height in the cooling layer. It is projected that integration of wireless network on chip architecture could alleviate these height restrictions since the data bandwidth is independent of the communication lengths. Microchannels that are 200 μm or larger in depth are expected to allow dissipation of large heat fluxes with significantly lower pressure drops.

Sign in / Sign up

Export Citation Format

Share Document