Study On Ice Blockage Of Scraping Fluidized Ice Making Machine For Fishing Vessels

Freshness-preservation technology on fishing vessels is a key link to ensure the quality of aquatic products in cold-chain logistics.Fluidized ice is a two-phase solution mixed with fine ice grains,which has the characteristics of high cleanliness,fine and round ice grains,and high latent heat of phase transformation.It has broad application prospects in freshness preservation on fishing vessels.However,after consulting and analyzing a large number of research literatures on the technology of fluidized ice production,it is found that ice blockage is a common problem in equipment used to produce fluidized ice,and the occurrence of ice blockage will affect the continuity of ice production.Therefore,this paper focuses on the ice blockage problem in the scraping-type fluidized ice machine,and mainly carries out the following work:(1)Establishment of the experimental platform: On the basis of consulting a large number of documents,the design idea of the control of the experimental platform of the fluidized ice machine and data acquisition system is put forward.The experimental platform of fluidized ice machine meets the requirements of smooth ice-production process,self-adjustable scraper speed and import flow,and accurate acquisition of equipment parameters in the process of ice-production;(2)Experimental study on the influencing factors of ice blockage: The control variable method was used to conduct the experimental study.By changing the mass fraction of ice-producing solution,the speed of scraper and the flow rate of imported ice,we analyzed the influence of the change of parameters on the degree of ice blockage of ice machine.The results show that: a.The change of mass fraction of ice-producing solution has little effect on the degree of ice blockage;the thickness of ice layer is less than 0.40 mm,and the degree of ice blockage is zero.b.The speed of scraper determines the heat transfer time of ice-producing solution: the smaller the speed of scraper,the longer the heat transfer time of ice-producing solution,the greater the degree of ice blockage in ice-producing machine will be.c.When the inlet flow rate is less than 1400L/h,the degree of ice blockage decreases with the decrease of the inlet flow rate;however,when the inlet flow rate is greater than 1400L/h,the ice thickness is the largest,which is 0.95 mm.d.When the speed of scraper and the inlet flow rate change simultaneously,the ice blockage degree of ice machine is greatly affected by the speed of scraper.e.When the ice thickness is in the range of 0.7-1.2 mm,the ice blockage can be prevented by increasing the speed of scraper or the inlet flow rate;(3)Research on ice-melting scheme when ice-blocking occurs: The ice-melting scheme suitable for scraping-type fluidized ice machine is put forward to quickly solve the ice-blocking problem.The ice model inside the ice cylinder is established when ice-blocking occurs,and the ice-melting process under this scheme is simulated by CFD software.Besides,the results of numerical simulation are compared and verified by experiments,which show that the melting speed of ice above the ice cylinder is faster than that below.The simulated total melting time is about 1372.2s.The average melting time obtained by experiments is 948.8s.The water flow in the melting process will accelerate the melting of ice,and the location of ice blockage and the amount of ice blockage are random;(4)Software development: According to the experimental results obtained in the previous experiments,a general window software for predicting the degree of ice blockage in fluidized ice machine was obtained by programming.As long as the users input the state parameters of the fluidized ice machine in the main interface,they can quickly know the degree of ice blockage of fluidized ice machine under the current parameter state through software.