Experimental Study On The Growth Period Properties Of Clathrate Hydrate

With the increasing emphasis on energy issues,the application of cold storage technology has received increasing attention.The ideal cold storage medium is the key to help the rapid development of cold storage technology.The advantage of clathrate hydrate as a cold storage medium is that the phase transition temperature is between 5°C and 12°C.It fits well with conventional air-conditioning systems,and does not require dual-operation air-conditioning systems.It does not reduce the air conditioning temperature due to cold storage conditions.Energy Efficiency Ratio?COP?of the system.At the same time,the unit volume of clathrate hydrate storage capacity is close to or greater than the unit volume of ice storage,which can effectively reduce the volume of the cold storage container.Based on the cold storage efficiency and economy of clathrate hydrate engineering applications,a series of experimental studies on the effect of various promoters on the growth rate of HCFC-141b?1,1-Dichloro-1-fluoroethane?clathrate hydrate during the growth period were carried out.The thermal properties were measured to provide an experimental basis for the application of cage hydrate to practical engineering.First,the article compares the addition of 0.1%by weight of kinetic promoters—sodium dodecyl sulfate?SDS?,sodium dodecylbenzenesulfonate,and perfluoroalkyl ether-alkoxy ammonium salt type anion Intechem-01?FC-01?and the thermodynamic promoters tetrahydrofuran?THF?and tetrabutylammonium bromide?TBAB?at 3°C under static conditions,the promotion effect of the HCFC-141b clathrate hydrate during the growth period.The promoters with the best promoting effect were selected,and the experimentally generated solid components were analyzed and determined using XRD,and further analyzed by particle size test and surface tension test.Then,the effects of different concentrations of FC-01 on the growth rate of HCFC-141b hydrate during the growth period were studied,the optimum concentration for the promotion of hydrate growth was obtained,and analyzed by the surface tension test;Next,the effect of different mass ratios of host and guest materials on the growth rate of HCFC-141b clathrate hydrate was studied.Finally,the latent heat of phase change of HCFC-141b hydrate was measured by differential scanning calorimetry?DSC?and cooling method.The cooling device was built and the thermal conductivity of HCFC-141b hydrate was measured and analyzed by Hot Disk.The results showed that 0.1%by weight of FC-01 added at a temperature of 3°C exhibited better growth promotion effect in the static preparation of HCFC-141b hydrate,and the solids in the samples added with FC-01 were analyzed by XRD.It was identified as a type II HCFC-141b hydrate,.Through the particle size analysis,the addition of FC-01 can make HCFC-141b/H₂O mixed liquid system have better dispersion effect and stability,and its particle size can be stable at 350nm for a long time,and can provide more for the hydration reaction.Reactors improve storage efficiency.The effects of different concentrations of FC-01 on the growth rate of HCFC-141b hydrate during the growth period were compared.It was found that when the FC-01 concentration was 0.06 wt%at 3°C,the growth rate of the HCFC-141b clathrate hydrate was the fastest.By testing the surface tension of 0.1 wt%of SDBS,SDS and FC-01 aqueous solutions,it was found that FC-01 had the best effect on reducing the surface tension of water.Different concentrations of FC-01 aqueous solution were tested.The results showed that the surface tension gradually decreased with the increase of FC-01 mass concentration,and then gradually decreased.The surface tension was basically stable at about 21mN/cm.19.94 mN/cm.In the HCFC-141b/H₂O mass ratio experiment,when the ratio is greater than 1:2.62,that is,HCFC-141b is excessive,the clathrate hydrates have a relatively faster growth rate and the excess HCFC-141b is easier to separate,which means that the excess storage material can be used to increase the cold storage rate in practical engineering applications.Because the phase transition point of HCFC-141b hydrate is 8.4°C and it is prone to phase separation,it is impossible to accurately measure the latent heat of phase change of HCFC-141b by using normal temperature DSC,and the latent heat of phase change was 174.22 J/g measured by the cooling method using an experimental device constructed by itself,which is closer to the actual engineering application;The thermal conductivity of the HCFC-141b clathrate hydrate was measured by the Hot Disk using a self-designed cooling device and the thermal conductivity was 0.435W?m^-1?K^-1,which provided the experimental basis for the equipment selection in the cold storage project.