Experimental Study On Cold Storage Properties Of TBAB Hydrate

In recent years, the application of cool storage technology has become increasingly widespread in the field of building energy conservation with the energy supply tension. For the development of storage technology, one of the key focus is to find an ideal heat storage medium. Hydrate storage refrigerant has attracted extensive attention due to the higher phase transition temperature. In this paper, water-soluble TBAB solution hydrated phase change thermal storage were studied experimentally, analyzed and optimized their storage characteristics and storage process.Firstly, this paper analyzed the characteristics of hydrate formation, phase transition energy and undercooling of different concentrations from 5% to 60% of TBAB solution by using differential scanning calorimetry with DSC thermal analyzer. Secondly, a makeshift bench was set up to analyzed the phase change process of the 42.5% concentration TBAB solution by using the step cooling curve method. Then by adding different quality TiO2 nanomaterials on the transformation process in the 7 degree cold source, compared the optimization effect comparison of different quality of TiO2 additives. Finally, the TPS1500 Hot-disk was used to test the thermal conductivity of pure TBAB solution and additive TiO2 solution based on the liquid testing device.The research found that the phase transition reaction could not occur when the solution concentration was less than 20%. When the solution concentration was between 20% to 30%, the phase transition coludn't be repeated. When the solution concentration was higher than 30%, the phase transition colud be recycled. And a concentration of 42.5% for the best storage solution of TBAB concentration, the phase transition can be a maximum of 172.9 J/g. In addition, the research found that the TBAB solution has a relatively stable solidification and melting temperature, but there is a large undercooling. Step cooling curve experiments found that the solidification temperature of TBAB solution at 0??2??5??7? cold source temperature is 6.7??9.6??11.3??11.7?, and the undercooling were 6.4 ?, 6.6 ?, 6.3 ?, 4.8 ?. And with the increase of cold source temperature, the latent heat of phase change platform session duration at 7 ? cold source grow to 140 min. The phase change process can be improved obviously with the addition of TiO2 nanomaterials, and the phase transition process is no longer apparent while reducing the undercooling of the TBAB solution. However, the exorbitant concentration of TiO2 nanomaterials additive will affect the hydrate formed of the hydration reaction. When TiO2 concentration was 3%, the undercooling can be reduced to 1.65 ?, and no significant effect on the hydration reaction and optimization results is the best. The thermal conductivity test results mean that thermal conductivity of pure TBAB solution with an average of 0.4245 w/(m??),adding TiO2 nanomaterials concentration to 3% solution of average thermal conductivity of 0.5124 w/(m??), thermal conductivity values increased by 20%.