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.

Numerical and Experimental Analysis for Air Circulation and Cooling Performance in a Cell Cabinet

2007 ◽  
Author(s):  
Jiahui Zhang ◽  
Jason Waggel ◽  
Dave Weber ◽  
Tony Pollice
Keyword(s):  
Heat Exchanger ◽  
Cooling System ◽  
Air Flow ◽  
Flow Distribution ◽  
Simulation Models ◽  
Cooling Capacity ◽  
Air Cooling ◽  
Application Range ◽  
A Cell ◽  
Air Circulation

In liquid-cooled large drives, controlling air temperature and maintaining air circulation is very important to the lifetime and functions of electrical and electronic components in power cell cabinet. In application, air/water heat exchangers and associated fans are employed to cool the air and force it through the cells. A computational fluid dynamics (CFD) analysis is performed to predict the air circulation in cell cabinet. The results are applied in air baffle arrangement to obtain an ideal air flow distribution. A fundamental analysis is conducted for heat exchanger and its thermal performance defined. It is found that the air supply temperature from heat exchanger is almost independent of air flow rate and altitude within application range. A thermal model is developed to simulate air temperatures into and out of cell cabinet heat exchanger for evaluating its cooling capacity. Flow and heat-run tests are performed for a cell cabinet. The testing results prove that the simulation models are accurate, and the developed air-cooling system can satisfy cooling requirement. A parametric study is complemented with the simulation models to guide cooling management regarding variations in operational and environmental conditions.

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.

Numerical Simulation on the Temperature Characteristics of Indirect Air Cooling System

2015 ◽  
Vol 741 ◽  
pp. 536-540
Author(s):  
Xiao Zhi Qiu ◽  
Yan Ming Zhao ◽  
Bao Hua Huang ◽  
Wei Xu
Keyword(s):  
Numerical Simulation ◽  
Wind Speed ◽  
Cooling System ◽  
System Change ◽  
Temperature Characteristic ◽  
Air Cooling ◽  
Ansys Software ◽  
System A ◽  
Air Cooling System ◽  
Simulation Results

Based on the analysis of indirect air cooling system, a numerical simulation model of indirect air cooling system was constructed by ANSYS software. According to the different wind speed condition, the temperature characteristic of indirect air cooling system was analyzed. The simulation results show that with the increase of wind speed, the ventilation and heat release of the indirect air cooling system change greatly. It provides a theoretical basis for the design of the wind-proof device of indirect air cooling system.

Rechargeable Personal Air Conditioning Device

2016 ◽  
Author(s):  
Yilin Du ◽  
Jan Muehlbauer ◽  
Jiazhen Ling ◽  
Vikrant Aute ◽  
Yunho Hwang ◽  
...  
Keyword(s):  
Air Conditioning ◽  
Cooling System ◽  
Cooling Capacity ◽  
Comfort Level ◽  
Vapor Compression ◽  
Air Conditioning System ◽  
System A ◽  
Single Person ◽  
Vapor Compression Cycle ◽  
Compression Cycle

A rechargeable personal air-conditioning (RPAC) device was developed to provide an improved thermal comfort level for individuals in inadequately cooled environments. This device is a battery powered air-conditioning system with the phase change material (PCM) for heat storage. The condenser heat is stored in the PCM during the cooling operation and is discharged while the battery is charged by using the vapor compression cycle as a thermosiphon loop. The conditioned air is discharged towards a single person through adjustable nozzle. The main focus of the current research was on the development of the cooling system. A 100 W cooling capacity prototype was designed, built, and tested. The cooling capacity of the vapor compression cycle measured was 165.6 W. The PCM was recharged in nearly 8 hours under thermosiphon mode. When this device is used in the controlled built environment, the thermostat setting can be increased so that building air conditioning energy can be saved by about 5–10%.

An Overview of Different Indirect and Semi-Indirect Evaporative Cooling System for Study Potency of Nanopore Skinless Bamboo as An Evaporative Cooling New Porous Material

2021 ◽  
Vol 79 (2) ◽  
pp. 123-130
Author(s):  
I Nyoman Suprapta Winaya ◽  
Hendra Wijaksana ◽  
Made Sucipta ◽  
Ainul Ghurri
Keyword(s):  
Energy Consumption ◽  
Porous Material ◽  
Cooling System ◽  
Evaporative Cooling ◽  
Temperature Drop ◽  
High Energy ◽  
Dew Point ◽  
Air Cooling ◽  
Evaporative Cooling System ◽  
Indirect Evaporative Cooling

The high energy consumption of compressor based cooling system has prompted the researchers to study and develop non-compressor based cooling system that less energy consumption, less environment damaging but still has high enough cooling performances. Indirect and semi indirect evaporative cooling system is the feasible non-compressor based cooling systems that can reach the cooling performance required. This two evaporative cooling system has some different in construction, porous material used, airflow scheme and secondary air cooling method used for various applications. This paper would report the cooling performances achieved by those two cooling system in terms of cooling efficiency, cooling capacity, wet bulb effectiveness, dew point effectiveness, and temperature drop. Porous material used in indirect and semi-indirect evaporative cooling would be highlighted in terms of their type, size, thickness and any other feature. The introduction of nanopore skinless bamboo potency as a new porous material for either indirect or semi-indirect evaporative cooling would be described. In the future study of nanopore skinless bamboo, a surface morphology and several hygrothermal test including sorption, water vapor transmission, thermal conductivity test would be applied, before it utilize as a new porous material for direct or semi indirect evaporative cooling.

scholarly journals Numerical Simulation of the Air Cooling System for Scientific Payload Rack on a Space Station

Energies ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 6145
Author(s):  
Yuan-Yuan Lou ◽  
Ben-Yuan Cai ◽  
Yun-Ze Li ◽  
Jia-Xin Li ◽  
En-Hui Li
Keyword(s):  
Numerical Simulation ◽  
Cooling System ◽  
Space Station ◽  
Thermal Control ◽  
Physical Models ◽  
Air Cooling ◽  
Ansys Fluent ◽  
System A ◽  
Air Cooling System ◽  
Scientific Payload

The space scientific payload rack is a multifunctional experimental platform, and the requirements of the environmental temperature index are different for diversified experimental modules inside. The air cooling system is an important part of the rack thermal control system. A new type of air cooling system with small size and flexible arrangement is proposed in this paper, that is, micro air ducts with pinhole-sized air vents. The rack physical models of new and traditional air cooling modes are established, respectively. The numerical simulation of the inner air flow is carried out by Ansys Fluent CFD software (Ansys Inc., Canonsburg, PA, USA), which verifies that compared with the traditional method, the temperature field and flow field of the new air cooling method are more uniform, and the heat sources located at the edge of the rack can also be cooled better.

scholarly journals Gas turbine unite inlet air cooling by using an excessive refrigeration capacity of absorption-ejector chiller in booster air cooler

2018 ◽  
Vol 70 ◽  
pp. 03012 ◽  
Author(s):  
Roman Radchenko ◽  
Andrii Radchenko ◽  
Serhiy Serbin ◽  
Serhiy Kantor ◽  
Bohdan Portnoi
Keyword(s):  
Gas Turbine ◽  
Cooling System ◽  
Ambient Air ◽  
Cooling Capacity ◽  
Climatic Conditions ◽  
Air Cooling ◽  
Two Stage ◽  
Air Cooler ◽  
Refrigeration Capacity ◽  
Heat Loads

Two-stage Gas turbine unite (GTU) inlet air cooling by absorption lithium-bromide chiller (ACh) to the temperature 15 °C and by refrigerant ejector chiller (ECh) to 10 °C through utilizing the turbine exhaust gas heat for changeable ambient air temperatures and corresponding heat loads on the air coolers for the south Ukraine climatic conditions is analysed. An excessive refrigeration capacity of combined absorption-ejector chiller (AECh) exceeding the current heat loads and generated at decreased heat loads on the air coolers at the inlet of GTU can be used for covering increased heat loads to reduce the refrigeration capacity of AECh. The GTU inlet air cooling system with an ambient air precooling booster stage and a base two-stage cooling air to the temperature 10 °C by AECh is proposed. The AECh excessive cooling capacity generated during decreased heat loads on the GTU inlet air coolers is conserved in the thermal accumulator and used for GTU inlet air precooling in a booster stage of air cooler during increased heat loads. There is AECh cooling capacity reduction by 50% due to the use of a booster stage for precooling GTU inlet ambient air at the expense of an excessive cooling capacity accumulated in the thermal storage.

Design, Construction, and Characterization of an Adjustable 70 kW High-Flux Solar Simulator

2016 ◽  
Vol 138 (4) ◽  
Author(s):  
Jinliang Xu ◽  
Cheng Tang ◽  
Yongpan Cheng ◽  
Zijin Li ◽  
Hui Cao ◽  
...  
Keyword(s):  
Focal Plane ◽  
Cooling System ◽  
Air Cooling ◽  
Power Capacity ◽  
Solar Simulator ◽  
Participating Media ◽  
System A ◽  
Full Power ◽  
Design Construction

The design, construction, and characterization of a solar simulator are reported. The solar simulator consists of an optical system, a power source system, an air cooling system, a control system, and a calibration system. Seven xenon short-arc lamps were used, each consuming 10 kW electricity. The lamps were aligned at the reflector ellipsoidal axis. The stochastic Monte Carlo method analyzed the interactions between light rays and reflector surfaces as well as participating media. The seven lamps have a common focal plane. The focal plane diameters can be changed in the range of 60–120 mm with the lamp module traveling the distance in a range of 0–300 mm. The calibration process established a linear relationship between irradiant fluxes and grayscale values. The measures to reduce irradiant flux error and fluctuations were described. The irradiant flux distribution can be changed by varying the power capacities and/or moving the focal plane locations. The peak fluxes are 1.92, 3.16, and 3.91 MW/m2 for 25%, 50%, and 75% of the full power capacity. The peak flux and temperature exceed 4 MW/m2 and 2300 K, respectively, for the full power capacity. A 8 cm thick refractory brick can be melt in 2 min with the melting temperature of about 2300 K when the solar simulator is operating at 70% of the maximum power capacity.

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