The Analysis And Experiment On Ice Slurry Generation Based On Scraper Type

Ice slurry is a kind of solid-liquid two-phase solution which composed of water, iceparticles, and freezing point modifier (ethanol, sodium chloride, ethylene glycol, etc.), andit equipped with good fluidity and giant phase change latent heat, can be used as a goodkind of coolant for storage and transportation of large-scale and high-density cold energy.Ice slurry technology has been widely used in the fields of district cooling, building airconditioning, food refrigeration and industrial cooling, and some potential applications likefire fighting, the mine cooling and rapid cooling of the human organs. Currently the methodof ice slurry making mainly contains scraping type, supercooled water type, fluidized bedtype, the vacuum process and the direct contact type. In view of the laboratory conditions,in the analysis of the advantages and disadvantages of various dynamic ice slurry makingtypes, Select the scraping type with more stability when system runs. Subjects for thesodium chloride solution.Based on the scraping type used in the ice making apparatus, this paper analysis bothof the characteristics of water and ice crystal growth process. Give focus analysis of thesurface nucleation mechanism, and the Gibbs free energy for phase change is deduced.Indicates that the growth of ice crystals are promoted depending on the degree ofsupercooling. Refer to the physical parameters of the sodium chloride solution on thechlorine alkali manual, use gambit software to geometric modeling and meshing boundaryon evaporator, then import to the Fluent software, carry on numerical simulation for thetemperature and the Solidification process of the sodium chloride solution by usingSolidification and Melting model, and obtain the temperature changed gradually from thewall to the central in the process of cooling solidification, the distribution of temperaturegradient is equilibrium; The separation time of phases will increase when concentrationincreases.Through the selection of systems, built the experimental apparatus with scraping typefor ice slurry making. The scraper in the ice slurry generator was designed with PTFEboard, symmetrical distribution on the inner wall of the generator, it will scraping icecrystals attached on the wall when the centre drive shaft runs. Also establishsd a set of dataacquisition system, give real-time monitoring and recording to the temperature and pressureof the compressor suction and discharge during the experiment; the temperature andpressure before and after the throttle valve; the temperature and flow rate of the sodiumchloride solution in the import and export of generator；the temperature and flow rate ofthe cooling water. This paper analysised the cooling process of different concentrations of sodium chloridesolution. Experiments showed that: the values of freezing point under differentconcentrations of sodium chloride solution are larger than the chlor-alkali manual. Thebiggest occurred at5%deviation; The latent heat decreased with the increase of theconcentration, the latent heat dropped more obvious after more than5%; System energyefficiency factor increased first and then decreased during the experiment, the valueremained stable at about0.6.