15 research outputs found
Numerická simulace pĹ™enosu hmoty mezi amoniakem a vodou v absorpÄŤnĂm chilleru
ÄŚlánek popisuje absorpÄŤnĂ proces plynnĂ©ho amoniaku do kapalnĂ© vody v deskovĂ©m tepelnĂ©m vĂ˝mÄ›nĂku, kterĂ˝ je povaĹľován za kritickou část absorpÄŤnĂho chladicĂho systĂ©mu. Jsou aplikovány dva pĹ™Ăstupy pro numerickou simulaci absorpce. PrvnĂ pĹ™Ăstup spoÄŤĂvá v simulaci jak vlastnĂho rozpouštÄ›nĂ atomĹŻ plynnĂ©ho amoniaku v kapalnĂ© vodÄ›, tak i jejich následnĂ© chemickĂ© reakci s molekulami vody za vzniku hydroxidu. Ve druhĂ©m, zjednodušenĂ©m, pĹ™Ăstupu je simulována pouze prvnà část absorpce, tedy jen rozpouštÄ›nĂ molekul bez jejich následnĂ© reakce.This paper describes the absorption process of gaseous ammonia into liquid water in the plate heat exchanger, which is considered to be the crucial part of an absorption cooling system. Two approaches are utilized to numerically simulate this absorption process. In the first approach, the dissolution of gaseous ammonia into liquid water, as well as the following chemical reaction between the dissolved liquid ammonia and liquid water, are modeled. In the second approach, only the dissolution of ammonia into water is considered. The Henry’s Law with Van’t Hoff correlation is used for the simulation of the ammonia absorption process, namely the calculation of the concentration of ammonia in gas and in liquid. The Henry’s law is utilized since its line has the best correlation with the ammonia-water equilibrium line for the concentrations, which is taken into account in the numerical simulations. The ammonia mass flux from gas to liquid phase and its concentration at the outlet of the computational domain is determined as a result of the simulations