Experimental study on solving the blocking for the direct contact mobilized thermal energy storage container

As a promising technique of the waste heat recovery, the mobilized thermal energy storage (M-TES) can reduce the energy consumption and meet the heat demand for distributed users. With the convective heat transfer in the container, the direct contact M-TES shows a good charging and discharging performance except the blocking by the deposited phase change material (PCM) at the initial stage of the charging process. This paper studied a solution on forming the quick channels (QC) with electric heaters to solve the blocking issue. Phase change behaviors of PCM in the container with and without QC were analyzed and compared. With the QC formed with electric heaters, the charging time at the early and middle stage is obviously shortened compared with that of the experiment without electric heating. However, the solution is not suitable at later stage of charging because of the fading away of QC. The formation of QC takes about 90 s and covers around 5% of the thermal energy stored in the container. The results present that it is a good method to solve the blocking issue for the direct contact M-TES system especially with a low rate of heat release. [Display omitted] •Analyzing the reason of blocking in direct contact M-TES container.•Designing an option to solve the blocking by using electric heaters.•Comparing the melting and solidification behaviors of PCM in direct contact M-TES container with and without quick channels.