Flow boiling heat transfer and pressure drop of hydrocarbons R600a and R290 in a multiport mini channel tube
Jacqueline Copetti1, Mario Macagnan1, Jeferson OLiveira3, Priscila Silva4.
1Unisinos - Universidade do Vale do Rio dos Sinos, São Leopoldo, Brazil; 2Unisinos - Universidade do Vale do Rio dos Sinos, São Leopoldo, Brazil; 3FSG - Faculdade da Serra Gaúcha, Caxias do Sul, Brazil; 4Unisinos, São Leopoldo, Brazil
The design of compact evaporators for refrigeration systems has motivated the research in boiling in small geometries for better understanding of heat transfer and pressure drop and modelling improvement.
This work presents the results of experimental studies of flow boiling of R600a and R290, in a 7-minichannel multiport tube with 1.47 mm ID. The effects of heat flux q from 5 to 25 kW/m², mass flux G from 35 to 165 kg/m²s and vapor quality on heat transfer coefficient h and pressure drop ∆p were studied for Tsat of 20 ºC.
The h reached values up to 18 and 9 kW/m²K for R290 and R600a, respectively. The influence of G on ∆p was observed, and the highest loss for R600a. The flow patterns during the tests were plug, slug and annular, but with differences in channels.
The paper analyzes the effects of patterns, associated with refrigerants properties, in the behavior of h and ∆p, contributing for the research area and the applicability of these refrigerants.
