Abo Bibliothek: Guest

ISSN Online: 2377-424X

ISBN Print: 978-1-56700-474-8

ISBN Online: 978-1-56700-473-1

International Heat Transfer Conference 16
August, 10-15, 2018, Beijing, China

ENTRANSY OF WATER VAPOR AND ITS BALANCE EQUATION FOR HEAT AND MASS TRANSFER PROCESS IN THE ABSORBER

Get access (open in a dialog) DOI: 10.1615/IHTC16.mtr.023227
pages 5795-5802

Abstrakt

Absorption heat pumps have been widely used in waste heat recovery and district heating in recent years. The absorber is the key component of the absorption system. In order to evaluate the performance of the absorber, an entransy-dissipation-based method is used to analyze the heat and mass transfer process in the absorber. As the temperature at which the water vapor releases its liquefaction heat varies with the concentration of the solution, latent heat entransy is defined for the water vapor. For the commonly used vertical falling film absorber, the finite difference model is made and the entransy balance equation of the absorber is obtained based on the new definition. Then, a simulation is conducted using the model to compare the entransy dissipation between the mass transfer and the heat transfer process. The results show that the latent heat entransy dissipation caused by mass transfer and the sensible heat entransy dissipation caused by heat transfer are 16.05 kW·K and 25.88 kW·K, respectively. This means the dissipation in the vapor absorbing process is of the same magnitude as that in the heat transfer between the solution and the cooling water. Therefore, the dissipation in the mass transfer process in the internal absorber is not negligible in the future analysis.