MODIFIED METHOD OF TRANSFER UNITS FOR CALCULATING FILM COOLING TOWERS
Rubrics: 2. CHEMICAL TECHNOLOGY
Authors:
1.
KGEU
2.
Kazan National Research Technological University
3.
Saint Petersburg Mining University
Type:
Article
Pages:
from 75
to 80
Status:
Published
Received:
24.12.2025
Accepted:
25.12.2025
Published:
25.12.2025
Language:
Russian
Keywords:
COOLING TOWERS, FILM MODE, HEAT AND MASS TRANSFER, FLOW STRUCTURE, WATER COOLING, PROCESS EFFICIENCY
Abstract (English):
Film counterflow cooling towers designed to cool water with atmospheric air are considered. To increase the reliability of calculating the design characteristics of film cooling towers, namely the height of regular contact devices, a modification of the transfer unit method was performed using the example of a rolled polymer mesh nozzle, which makes it possible to take into account the reverse (longitudinal) mixing of water and air. Experimental data obtained earlier by the authors on the hydraulic and mass transfer characteristics of a rolled mesh nozzle in the film mode in the counterflow of phases are used. The modification of the method consists in the introduction of additional terms to the height of the transfer units in the form of Peclet numbers (Bodenstein criteria), which is used by various authors in the calculation of nozzle absorbers and liquid-phase extractors, as well as nozzle gas separators for the separation of aerosol systems. Due to the additional components, the required height of the regular nozzle increases by 5-20%, which increases the accuracy of calculating the film cooling tower at a given temperature and phase flow. Calculated expressions for the thermal efficiency of air heating and water cooling are presented. Empirical and theoretical equations are given for calculating volumetric mass transfer coefficients for various contact devices in an intense turbulent regime of air movement when interacting with a flowing film of water. In theoretical terms, the main information is the hydraulic resistance of the irrigated nozzle and the coefficient of the active surface of the mass transfer. Examples of calculations of the nozzle height and heat transfer efficiency at a given temperature regime of the cooling tower are shown. The effect of reverse mixing of phases on the efficiency of water cooling has been established. The modified thermal calculation method presented here can be used in the design or modernization of film cooling towers in various industries and energy sectors.
Film counterflow cooling towers designed to cool water with atmospheric air are considered. To increase the reliability of calculating the design characteristics of film cooling towers, namely the height of regular contact devices, a modification of the transfer unit method was performed using the example of a rolled polymer mesh nozzle, which makes it possible to take into account the reverse (longitudinal) mixing of water and air. Experimental data obtained earlier by the authors on the hydraulic and mass transfer characteristics of a rolled mesh nozzle in the film mode in the counterflow of phases are used. The modification of the method consists in the introduction of additional terms to the height of the transfer units in the form of Peclet numbers (Bodenstein criteria), which is used by various authors in the calculation of nozzle absorbers and liquid-phase extractors, as well as nozzle gas separators for the separation of aerosol systems. Due to the additional components, the required height of the regular nozzle increases by 5-20%, which increases the accuracy of calculating the film cooling tower at a given temperature and phase flow. Calculated expressions for the thermal efficiency of air heating and water cooling are presented. Empirical and theoretical equations are given for calculating volumetric mass transfer coefficients for various contact devices in an intense turbulent regime of air movement when interacting with a flowing film of water. In theoretical terms, the main information is the hydraulic resistance of the irrigated nozzle and the coefficient of the active surface of the mass transfer. Examples of calculations of the nozzle height and heat transfer efficiency at a given temperature regime of the cooling tower are shown. The effect of reverse mixing of phases on the efficiency of water cooling has been established. The modified thermal calculation method presented here can be used in the design or modernization of film cooling towers in various industries and energy sectors.
Keywords:
COOLING TOWERS, FILM MODE, HEAT AND MASS TRANSFER, FLOW STRUCTURE, WATER COOLING, PROCESS EFFICIENCY
COOLING TOWERS, FILM MODE, HEAT AND MASS TRANSFER, FLOW STRUCTURE, WATER COOLING, PROCESS EFFICIENCY
