Water Mist Flashover Suppression and Boundary Cooling System for Integration with DC-ARM Volume 1: Summary of Testing

1999 ◽  
Author(s):  
J. Mawhinney ◽  
P. J. DiNenno ◽  
F. W. Williams
Keyword(s):  
Cooling System ◽  
Water Mist

Water-Mist-Cooled Heat Sink for Autonomous Air-Cooling System (AACS) of More Electric Aircraft (MEA)

2016 ◽  
Author(s):  
Akira Murata ◽  
Hiroshi Saito ◽  
Yoji Okita
Keyword(s):  
Heat Sink ◽  
Cooling System ◽  
Water Mist ◽  
Air Cooling ◽  
Cooling Performance ◽  
Motor Controller ◽  
Electric Aircraft ◽  
Air Cooling System ◽  
Cooling Air ◽  
More Electric Aircraft

The More Electric Aircraft (MEA) is a system architecture concept for the aircraft that reduces fuel consumption and environmental load while improving safety, reliability, and maintainability. MEA architecture replaces some of the conventional hydraulic and/or mechanical control system with electric motor-driven system, integrates system power management into the aircraft/engine controls, and optimizes the aircraft geometry by flexibly arranging the accessory devices. The primary challenge to realize the MEA concept is how to manage the heat from these additional power electronic devices. The authors’ group proposed novel cooling system, the Autonomous Air-Cooling System (AACS) which cools the power electronics of the motor devices distributed in the aircraft. In AACS, each power electronic device (e.g. motor controller) is air-cooled by heat sinks connected to compact blowers. This system is very simple and efficient since it re-uses the cabin air and needs no additional coolant. One of the key technologies which realize AACS is an efficient heat sink. In this study, at first the performance evaluation targeting a single-aisle 180-seater aircraft was performed. In the analysis, a plate-fin heat sink was adopted, and the pressure loss and heat transfer was estimated by using empirical correlations. In the analysis, the value of heat generation was assumed from power demand for each operation condition, and the required mass flow rate of cooling air was calculated so as for the enclosure temperature of the power electronics to be 80°C which was the allowable maximum temperature of the motor controller. The effect of the fin geometry on the cooling performance was also examined by varying the geometric parameters (fin height, thickness, and spacing). In order to further enhance the cooling performance without increasing the pressure loss, the water-mist injection to the cooling air flow was adopted and its effect was analytically confirmed. In addition, the effectiveness of the water-mist injection on the cooling performance was verified by performing experiments for a plate-fin heat sink manufactured by a wire electric discharge method.

scholarly journals Effect of Multipoint Sequential Water Mist Cooling of Casting Die on Microstructure and Mechanical Properties of AlSi11 Alloy

2012 ◽  
Vol 12 (4) ◽  
pp. 145-150
Author(s):  
R. Władysiak
Keyword(s):  
Mechanical Properties ◽  
Cooling System ◽  
Die Casting ◽  
Computer Control ◽  
Casting Process ◽  
Water Mist ◽  
Microstructure And Mechanical Properties ◽  
Casting Cycle ◽  
Mist Cooling ◽  
Die Casting Process

Abstract The work is a continuation of research on the use of water mist cooling in order to increase efficiency of the die-casting process for aluminum alloys. The paper describes the multipoint sequential cooling system of the casting die and its computer control and monitoring. It also includes results of the tests and analysis of cooling methods during making of the casting. These methods differ from each other in the sequence of casting die cooling and cause effective changes in microstructure and mechanical properties of castings made of AlSi11 alloy. The study demonstrated that the use of multipoint sequential cooling with water mist affects the microstructure refinement and reduces the segregation in the cast as well as more than by 20% increases the mechanical properties of castings in the rough state. The study also demonstrates that the sequential cooling of casting die accelerates the cooling of the casting and shortens die-casting cycle.

Experimental study of an ultrasonic regenerative evaporative cooler for a desiccant cooling system

2018 ◽  
Vol 40 (2) ◽  
pp. 151-175 ◽  
Author(s):  
BS Arun ◽  
V Mariappan
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Cooling System ◽  
Cooling Capacity ◽  
Water Mist ◽  
Extraction Ratio ◽  
Feed Water ◽  
Airflow Rate ◽  
Evaporative Cooler

This paper presents fabrication of an ultrasonic regenerative evaporative cooler, coupled with a desiccant dehumidifier. Ultrasonic regenerative evaporative cooler consists of several sets of a dry channel and a wet channel. A part of the air from the dry channel is redirected into the wet channel where it is cooled by evaporation of water mist from an ultrasonic atomiser. Air flowing through dry channels is pre-cooled by heat transfer between wet and dry channels, without changing its humidity. In this cooler, the conventional hygroscopic layer for wetting the plate surface is replaced with the water mist. It is observed that the performance of the cooling system significantly depends on the channel spacing, channel length, inlet airflow rate and extraction ratio, and marginally depends upon feed water temperature. The room cooling capacity is eminently responsive to both air mass flow rate and extraction ratio. The maximum available room cooling capacity of 339.8 W is obtained for the optimal values of 0.0488 kg/s mass flow rate of air and 0.37 extraction ratio. The prototype achieved wet-bulb effectiveness values as high as 1.15 and delivered more than 10℃ temperature drop. Practical application: An ultrasonic regenerative evaporative cooler can be coupled with a desiccant dehumidification unit for use in hot and humid climate to achieve comfort condition utilising less energy and feed water when compared to the vapour compression refrigeration system. From this prototype researchers and engineers can develop, by combining desiccant regenerators and evaporative coolers which use ultrasonic method for low-temperature dehydration of desiccant substance. Solar thermal energy can also be directly utilised for marginally heating the desiccant substance during the regeneration process. Overall, this system can contribute to the development of energy efficient buildings.

scholarly journals Structure of AlSi20 Alloy in Heat Treated Die Casting

2015 ◽  
Vol 15 (1) ◽  
pp. 113-118 ◽  
Author(s):  
R. Władysiak ◽  
A. Kozuń
Keyword(s):  
Cooling System ◽  
Die Casting ◽  
Computer Control ◽  
Water Mist ◽  
Research Station ◽  
Heat Treated ◽  
Wide Range ◽  
Mist Cooling ◽  
Casting Aluminum ◽  
Hypereutectic Silumins

Abstract The work is a continuation of research on the use of water mist cooling in order to increase efficiency of die-casting aluminum alloys using multipoint water mist cooling system. The paper presents results of investigation on crystallization process and microstructure of synthetic hypereutectic AlSi20 alloy. Casts were made in permanent mold cooled a with water mist stream. The study was conducted for unmodified AlSi20 alloy and a modified one with phosphorus, titanium and boron on the research station allowing sequential multipoint cooling using a dedicated program of computer control. The study demonstrated that the use of mold cooled with water mist stream and solution heat treatment allows in wide range for the formation of the microstructure of hypereutectic silumins. It leads to the growth of microstructure refinement and spheroidizing of phases in the casting.

scholarly journals Development of a water-mist cooling system: A 12,500 Kcal/h air-cooled chiller

2015 ◽  
Vol 1 ◽  
pp. 123-128 ◽  
Author(s):  
Chung-Neng Huang ◽  
Ying-Han Ye
Keyword(s):  
Cooling System ◽  
Water Mist ◽  
System A ◽  
Mist Cooling

scholarly journals Effect of Water Mist Cooling on Microstructure of Hypereutectic Al-Si Alloy

2014 ◽  
Vol 14 (3) ◽  
pp. 117-122 ◽  
Author(s):  
R. Władysiak ◽  
A. Kozuń
Keyword(s):  
Cooling System ◽  
Computer Control ◽  
Water Mist ◽  
Research Station ◽  
Solidification Temperature ◽  
Wide Range ◽  
Mist Cooling ◽  
Casting Aluminum ◽  
Hypereutectic Silumins ◽  
Made In

Abstract The work is a continuation of research on the use water mist cooling in order to increase efficiency of die-casting aluminum alloys using multipoint water mist cooling system. The paper presents results of investigation of crystallization process and microstructure of synthetic hypereutectic AlSi20 alloy. Casts were made in permanent mold cooled with water mist stream. The study was conducted for unmodified AlSi20 alloy and modified with phosphorus, titanium and boron on the research station allowing sequential multipoint cooling using a dedicated program of computer control. The study demonstrated that the use of mold cooled with water mist stream allows the formation of the microstructure of hypereutectic silumins. A wide range of solidification temperature of hypereutectic silumins increases the potential impact of changes in the cooling rate on a size, a number and a morphology of preeutectic silicon and eutectic α+β (Al+Si).

scholarly journals Analysis of Crystallization Process of Intensive Cooled AlSi20CuNiCoMg Alloy

2017 ◽  
Vol 17 (2) ◽  
pp. 137-144 ◽  
Author(s):  
R. Władysiak ◽  
A. Kozuń ◽  
K. Dębowska ◽  
T. Pacyniak
Keyword(s):  
Thermal Imaging ◽  
Crystallization Process ◽  
Cooling System ◽  
Computer Control ◽  
Solidification Process ◽  
Water Mist ◽  
Research Station ◽  
Wide Range ◽  
Imaging Camera ◽  
Mist Cooling

Abstract The work is a continuation of research concerning the influence of intensive cooling of permanent mold in order to increase the casting efficiency of aluminium alloys using the multipoint water mist cooling system. The paper presents results of investigation of crystallization process and microstructure of multicomponent synthetic hypereutectic alloy AlSi20CuNiCoMg. The study was conducted for unmodified silumin on the research station allowing the cooling of the special permanent sampler using a program of computer control. Furthermore, the study used a thermal imaging camera to analyze the solidification process of multicomponent alloy. The study demonstrated that the use of mold cooled with water mist stream allows in wide range to form the microstructure of hypereutectic multicomponent silumin. It leads to higher homogeneity of microstructure and refinement of crystallizing phases of casting.

scholarly journals Economical aspects of water-mist assisted air-cooled chillers usage in the temperate climate

2018 ◽  
Vol 245 ◽  
pp. 06013
Author(s):  
Arturs Brahmanis ◽  
Anatolijs Borodinecs ◽  
Jelena Tihana ◽  
Jurgis Zemitis ◽  
Daria Monastyreva
Keyword(s):  
Energy Consumption ◽  
Power Distribution ◽  
Cooling System ◽  
Influence Factors ◽  
Water Mist ◽  
Temperate Climate ◽  
Base Temperature ◽  
Outdoor Air ◽  
Global Trends ◽  
The Baltic

The prices for energy resources, global trends for greenhouse gases emission limitation makes the application of higher efficient chillers with process air evaporative cooling more common. In order to determine the economical feasibility for choosing the particular type of cooling unit for the specific building, many factors should be taken into account, which are not always available. One of these factors is the European seasonal energy efficiency ratio (ESEER) defined by the Eurovent Certification Company. It overtakes the outdoor air temperatures from +20° to +35°C with different cooling loads, which is not completely suitable for the Baltic States. Within the research monitoring of cooling system and air parameters was performed during the cooling season. It was indicated that the distribution of the energy generated by the investigated object differs significantly from the distribution of influence factors according to ESEER test methodology. The calculation of the annual energy consumption for the particular historic building according to the recorded power distribution within the outdoor air temperature ranges was performed. Using the proposed method the results are much closer to the actual annual energy consumption of the cooling plant than the one performed using the seasonal efficiency with the base temperature of 18°C.

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