Thermal Energy Storage Performance of Tetrabutylammonium Acrylate Hydrate as Phase Change Materials

Abstract

Kinetic characteristics of thermal energy storage (TES) using tetrabutylammonium acrylate (TBAAc) hydrate were experimentally evaluated for practical use as PCMs. Mechanical agitation or ultrasonic vibration was added to detach the hydrate adhesion on the heat exchanger, which could be a thermal resistance. The effect of the external forces also was evaluated by changing their rotation rate and frequency. When the agitation rate was 600 rpm, the system achieved TES density of 140 MJ/m3 in 2.9 hours. This value is comparable to the ideal performance of ice TES when its solid phase fraction is 45%. UA/V (U: thermal transfer coefficient, A: surface area of the heat exchange coil, V: volume of the TES medium) is known as an index of the ease of heat transfer in a heat exchanger. UA/V obtained in this study was comparable to that of other common heat exchangers, which means the equivalent performance would be available by setting the similar UA/V. In this study, we succeeded in obtaining practical data for heat storage by TBAAc hydrate. The data obtained in this study will be a great help for the practical application of hydrate heat storage in the future.

Special Issue on “Phase Change Materials: Design and Applications”

“…Ohmura and his team [5] conducted experiments on the investigation of hydrate heat storage systems. An evaluation of the kinetic characteristics of thermal energy storage using tetrabutylammonium acrylate hydrate as PCMs was performed.…”

Equilibrium Phase Relations and Dissociation Enthalpies of Tri-n-butylalkenylphosphonium Bromide Semiclathrate Hydrates

“…Different SCHs have to be used depending on the intended use. For example, the usage of SCHs in the air conditioning system, shipping boxes for medicine and/or fresh foods, and cooling systems of data centers and lithium-ion batteries for electric vehicle is expected. − As a way of tuning the equilibrium temperature of SCH, the replacement of anions has been well known and widely used. ,, Carboxylate anions with the different size of alkyl heads have been actively investigated. ,− As another way for tuning, the modification of quaternary onium cation as well as anion replacement has been investigated. ,− We recently reported the thermodynamic properties of tri- n -butylalkylphosphonium bromide (P444R-Br) SCHs, which exhibit a different size and shape of alkyl groups in phosphonium cations . In a previous study, propyl (R = 3), butyl (R = 4), and pentyl (R = 5) groups were adopted for the normal alkyl groups of the P444R-Br SCHs (the cation structures are shown in Figure ).…”

Hydrate Phase Equilibrium Data of Dimethyl Ether in the Presence of Tetrahydrofuran, Tetra-n-butylammonium Bromide, and Cyclopentane

“…) − and a nongas hydrate (such as semi-clathrate hydrate TBAB, TBAAc, etc. ). − A Gas hydrate, compared with a nongas hydrate, has a high cold storage density . However, it needs to provide a higher pressure to meet a suitable phase transition temperature, which limits its application.…”