Air cooling of concrete by means of embedded cooling pipes—Part II: Application in design

During construction in the Far North, due to the preservation of permafrost soils, the buildings are arranged on piles and foundations on the bedding soil. In the foundations of buildings for a smaller impact on the ground and prevention from defrosting of the soil, air cooling systems with cooling pipes are provided. Seasonal and daily variations in the temperature of the outside air and intensity of solar radiation cause fluctuations in the temperature regime of the upper layers of the soil. As a result of transformation of natural soils into technogenic, its physical properties change significantly when exposed to negative temperatures. Freezing of the soil thawed out over the summer and its further cooling is achieved by passing cold air in the winter through the air channels. The cooling system must provide the position of the upper surface of the frozen soil state under the building, as adopted by the project. This paper discusses the aerodynamic mode of the air cooling system for foundations on bedding in permafrost soils during the construction of various buildings and structures while preserving the base soils in a frozen state and using natural cold of the outside air, which will improve the reliability of permafrost bases. An engineering method has been developed for calculating the heat fluxes of soil and pipeline laid in thickness. A technique for engineering calculation of change in the thermal regime depending on the parameters of the outside air is given, which will make it possible to usefully use the energy of the cold enclosed in the ground to warm the outside air.

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Influence of Heat Treatments on Microstructures in an Fe-Co-V Alloy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100052572 ◽

1974 ◽

Vol 32 ◽

pp. 512-513

Author(s):

S. Mahajan ◽

M. R. Pinnel ◽

J. E. Bennett

Keyword(s):

Single Phase ◽

Alloy Composition ◽

Supersaturated Solid Solution ◽

Cell Formation ◽

Heat Treatments ◽

Air Cooling ◽

Iced Brine ◽

Transmission Electron ◽

The Matrix ◽

Bcc Structure

The microstructural changes in an Fe-Co-V alloy (composition by wt.%: 2.97 V, 48.70 Co, 47.34 Fe and balance impurities, such as C, P and Ni) resulting from different heat treatments have been evaluated by optical metallography and transmission electron microscopy. Results indicate that, on air cooling or quenching into iced-brine from the high temperature single phase ϒ (fcc) field, vanadium can be retained in a supersaturated solid solution (α2) which has bcc structure. For the range of cooling rates employed, a portion of the material appears to undergo the γ-α2 transformation massively and the remainder martensitically. Figure 1 shows dislocation topology in a region that may have transformed martensitically. Dislocations are homogeneously distributed throughout the matrix, and there is no evidence for cell formation. The majority of the dislocations project along the projections of <111> vectors onto the (111) plane, implying that they are predominantly of screw character.

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Crystallographic Differences of Metastable NI2MO in a NI-MO-AL Superalloy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s1431927600000672 ◽

1980 ◽

Vol 38 ◽

pp. 158-159

Author(s):

Michael M. Kersker ◽

E. A. Aigeltinger ◽

J. J. IIren

Keyword(s):

Mechanical Properties ◽

Air Cooling ◽

Solution Treated ◽

Heat Treated ◽

Metastable Compounds ◽

Rapidly Solidified

Ni-rich alloys based on approximate ternary composition Ni-8Mo-15A1 (at%) are presently under investigation in an attempt to study the contribution, if any, of the profusion of Mo-rich NixMo metastable compounds that these alloys contain to their excellent mechanical properties. One of the alloys containing metastable NixMo precipitates is RSR 197 of composition Ni-8.96Mo-15.06A1-1.98Ta-.015Yt. The alloy was prepared at Pratt and Whitney Government Products Division, West Palm Beach, Florida, from rapidly solidified powder. The powder was canned under inert conditions and extruded as rod at 1315°C. The as-extruded rod, after air cooling, was solution treated at 1315°C for two hours, air cooled, and heat treated for one hour at 815°C, followed again by air cooling.

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Air cooling

AccessScience ◽

10.1036/1097-8542.017100 ◽

2015 ◽

Keyword(s):

Air Cooling

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Large Portable Water Tanks, The Air-Cooling of 1923, and more

Scientific American ◽

10.1038/scientificamerican1222-397 ◽

1922 ◽

Vol 127 (6) ◽

pp. 397-397

Keyword(s):

Air Cooling ◽

Water Tanks

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ANALYSIS OF COMPETING VARIANTS OF AIR CONDITIONING SYSTEMS WITHOUT AIR EXTRACTION FROM ENGINES AT THE STAGE OF PASSENGER AIRCRAFT ONBOARD SYSTEMS CONCEPTUAL DESIGN

Computational nanotechnology ◽

10.33693/2313-223x-2019-6-3-86-91 ◽

2019 ◽

Vol 6 (3) ◽

pp. 80-85

Author(s):

Denis Igorevich Smagin ◽

Konstantin Igorevich Starostin ◽

Roman Sergeevich Savelyev ◽

Anatoly Anatolyevich Satin ◽

Anastasiya Romanovna Neveshkina ◽

...

Keyword(s):

Conceptual Design ◽

Air Conditioning ◽

Research University ◽

Cooling System ◽

Fuel Efficiency ◽

Air Cooling ◽

Moscow Aviation Institute ◽

Air Conditioning System ◽

Low Efficiency ◽

Air Conditioning Systems

One of the ways to achieve safety and comfort is to improve on-board air conditioning systems.The use of air cooling machine determines the air pressure high level at the point of selection from the aircraft engine compressor. Because of the aircraft operation in different modes and especially in the modes of small gas engines, deliberately high stages of selection have to be used for ensuring proper operation of the refrigeration machine in the modes of the aircraft small gas engines. Into force of this, most modes of aircraft operation have to throttle the pressure of the selected stage of selection, which, together with the low efficiency of the air cycle cooling system, makes the currently used air conditioning systems energy inefficient.A key feature of the architecture without air extraction from the main engines compressors is the use of electric drive compressors as a source of compressed air.A comparative analysis of competing variants of on-board air conditioning system without air extraction from engines for longrange aircraft projects was performed at the Moscow Aviation Institute (National Research University).The article deals with the main approaches to the decision-making process on the appearance of a promising aircraft on-board air conditioning system at the stage of its conceptual design and formulated the basic requirements for the structure of a complex criterion at different life cycle stages.The level of technical and technological risk, together with a larger installation weight, will require significant costs for development, testing, debugging and subsequent implementation, but at the same time on-board air conditioning system scheme without air extraction from the engines will achieve a significant increase in fuel efficiency at the level of the entire aircraft.

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