Використання особливостей процесів переносу при нагріві і випарному охолодженні плівки рідини на стадії проектування тепломасообмінних апаратів

• Datum: 2014
• Hauptverfasser: Tuz V.E., Lebed N.L.
• Format: Artikel
• Sprache: Ukrainian
• Veröffentlicht: General Energy Institute of the National Academy of Sciences of Ukraine 2014
• Schlagworte: плівка рідини; газовий потік; інтенсивність теплообміну; початкова теплова ділянка.
• Online Zugang: https://systemre.org/index.php/journal/article/view/537
• Назва журналу: System Research in Energy

In designing the heat-mass-exchange apparatuses of power units the changing characteristics of the heat exchange process along the length of the contact surface in order to improve the efficiency of equipment.In contact of the gravitational film with moving gas-vapor mixture, in addition to hydrodynamic and thermal boundary layers the diffusion boundary layer is also formed. In this case, the heat and mass transfer coefficients depend on the direction and value of the cross-flow mass.The solution of the combined differential equations describing heat and mass transfer processes in the system, is conducted with known values of middle surface heat and mass transfer coefficients. To obtain accurate result it is necessary to take into account the averaging of factor values at the initial area and the heat exchange area. To do this it is necessary to define the limits of the initial areas.Experimental study of heat and mass transfer processes in evaporative liquid and gas cooling allowed to establish a non-linear change of heat transfer coefficients and heat and mass transfer along the length of the channel.Based on the obtained results the dependencies were defined that allow to determine the length of the initial heat area depending on the operating conditions of the contacting phases and geometric channel characteristics.