Investigation of heat exchange of ice slurry flow in a coil.

The paper presents the results of investigations of heat exchange in a plate single-raw vertical coil of 6 horizontal tubes at coolant flowing in tubes. The coolant used was ice slurry or single-phase propylene glycol solution. Ice slurry is formed of propylene glycol water solution at mass concentration of 14 ± 2 %. The heat transfer coefficients dependences on density of heat flow of tubes were defined as well as on ice slurry rate through the coil and on concentration of water ice crystals in ice slurry. Ice slurry at ice concentration to 15% was investigated. It was defined that the heat transfer coefficient increased by 15-20% with increasing ice crystals concentration as compared with a single-phase coolant, but when concentration is higher than 5 the coefficients didn’t differ much at the same heat load. The increase of the heat flow density from 2 to 10 kW/m2 led to the heat transfer coefficients increasing by 25-30% on the average. To a considerable degree the heat transfer coefficients depend on the flow speed.