Calculations of the Outlet Air Conditions in the Direct Evaporative Cooler

Opportunities and prospects for the use of solar energy for refrigeration of public buildings

“…[3][4][5][6][7][8][9][10][11][12] for the heat balance of water flowing down the sloping plane is given. For simplicity, the friction forces between the air and the surface of the flowing water, and between the surfaces of the solid inclined plane on which the water flows and the surface of the flowing water are neglected [15][16][17][18][19][20]. 𝐺 𝑎specific flow rate of water flowing down the sloping plane, related to the unit width (a) of the evaporative radiant water cooling unit; 𝐶𝑝 𝑤is the specific heat capacity of water; 𝛼 𝑐𝑜𝑛is the convective heat transfer coefficient of the surface of the water flowing down the inclined plane with the environment; 𝛽 𝑃 -is the mass transfer coefficient of the evaporation surface of water flowing down a sloping plane with the environment, referred to a unit of the difference between the partial pressures of water vapour at the water evaporation surface (𝑃 𝑤 ) and in the environment (𝑃 о ); 𝑟latent heat of water evaporation; 𝛼 𝑟𝑎𝑑is the radiant heat transfer coefficient of the surface of water flowing down an inclined plane from the sky; 𝐾 𝑠𝑜𝑙𝑒transfer coefficient from the surroundings to the surface of the water flowing down the sloping plane through the insulated bottom of the evaporative radiant water cooling unit; 𝑡 𝑤the temperature of the water flowing down the inclined plane; 𝐿inclined plane length; 𝑑𝑡 𝑤 -is the temperature change of water flowing down an inclined plane on an elementary surface area of an evaporative radiant water cooling unit with length 𝑑𝐿 and area 𝑑𝐹.…”

“…where 𝛿 𝑖𝑛𝑠 and 𝜆 𝑖𝑛𝑠respectively, the thickness and thermal conductivity coefficient of the layer of a given thermal insulation of the installation (Eq. 25); 𝛼 𝑜𝑢𝑡 = 𝛼 𝑜𝑢𝑡 𝑐𝑜𝑛 + 𝛼 𝑜𝑢𝑡 𝑟𝑎𝑑 (25) 𝛼 𝑜𝑢𝑡coefficient of total (by convection and radiation) heat exchange of the surface of a given thermal insulation, the values of 𝛼 𝑜𝑢𝑡 𝑐𝑜𝑛 and 𝛼 𝑜𝑢𝑡 𝑟𝑎𝑑 can be determined from similar to (20) and (21) formulas with due regard to specific circumstances. 2).…”

Experimental investigation of air cooler using local palm tree waste

“…The saturation vapor pressure (e w ) in the wet-bulb temperature is given by [36] The saturation vapor pressure (e d ) in the dry bulb temperature is given by [36] The measuring humidity coefficient ðAÞ is given by…”