Pukhovyi I.I.

Using Cold from Snow, Ice and Ground for Cooling Small Data Centers in Ukraine

In this paper, we consider using renewable sources of cold (snow, ice and ground) for cooling server premises. We determine the required volumes of snow and ice for an average capacity of 10 kW during 7 months in southern regions of Ukraine and 4 months in the northern regions of Ukraine. The volume of snow and ice accumulators intended for 7 months of operation taking into account accumulation efficiency coefficient is about 2000 and 1000 tones. The ice and snow accumulators require the area from 50 to 300 square meters.

Flow and Water Freezing on Vertical Surfaces by Drops Irrigation Obtained by Blow Spraying

The paper under scrutiny studies the hydrodynamic parameters in the flow and wetting of solid metal plates and vertical grids of different materials under isothermal water flow and at its freezing on these surfaces. We conduct the experiments on water ice generation of the vertical galvanized metal and polymer plates with wetting density less than at the known minimum density of water wetting on dry and wet vertical surfaces. Ice formation and water cooling are conducted by water contact with frosty air.

Coefficients of Southward Orientation of Solar Collectors Depending on their Angles of Slope and Azimuth for Conditions in Ukraine

Based on the statistical data on the climate in Ukraine collected from both local and foreign sources, we determine coefficients of southward orientation of solar collectors. They are used at the dependence that considers the stream of solar radiation in clear sky, overcast expressed through power factors and coefficient of efficiency of flat solar collectors or passive systems of solar heating. In addition, we define that in summer more energy can be generated at the southern orientation and slope angles of about 30 degrees.

The Ice Wall Usage for Heating the Buffer Zone of Buildings by Heat of Water Crystallization and Determination of its Melting Time During Thaws

The paper considers the application of the ice wall in the buffer zone of the building to reduce heat losses from the residential area while water crystallization moving in a film on the inside or outside of the watering ice surface is described. The construction does not require the periodic ice removal. Furthermore, we calculate the temperatures and other thermal characteristics under the conditions with and without watering. When the thermal resistance of heat transfer from the residential area increases, the efficiency of heat water crystallization usage rises.

The Experimental Study of Detachable and Attachable Flow Limits of Liquid Film on the External Surface of Rotating Cone

The paper studies detachable and attachable flow limits of liquid film on the external surface of the rotating cone with different angles at the foundation (from 30 to 55 degrees) in the range from 400 to 1700 rpm with the fluid flow up to 45,2 g/s. The film flow in the lift-off zone looks like radial convex streams, from which droplets are falling. The bulk of the liquid flame spray is formed. The angle cosine at the cone base influences the most the beginning of droplets falling from the film surface.