Development of high-density heat storage technology that contributes to the effective use of heat energy

Toho Gas Co., Ltd.

Thermal storage material feasibility evaluation

Outline

With the objective of working for the effective utilization of unused heat in a wide variety of applications, we are working on developing performance improvements for high-density heat storage materials as well as expanding the range of usage temperatures for heat storage materials and opening up applications for them. In this way, we will promote the utilization of unused heat in a wide variety of fields and contribute to further energy conservation.

Description

With the objective of working for the effective utilization of gas cogeneration waste heat and other forms of heat energy, we are working on developing high-density heat storage materials as well as developing high-density heat storage technology using these materials. In particular, it is difficult to effectively use low-temperature waste heat at temperatures below 100˚C and for some temperature bands, no heat storage material has been developed. For these reasons, we have launched developed of heat storage materials that can be used for low-temperature waste heat.

We discovered heat storage materials that have about 2 times the heat storage density of existing heat storage material (paraffin) and 10 times that of warm water under the conditions of the waste heat temperature band (80-90˚C) of gas engines. We have also established foundational technology for adjusting the heat storage and heat release temperature band to about 40 to 90˚C while maintaining high heat storage density.

We have made a prototype of heat storage vats in which containers filled with heat storage material are loaded, and connected it to gas engine cogeneration. Now we are conducting feasibility evaluation under actual operating conditions. Through this evaluation, we aim to discover the optimum layout of containers to make it possible for the heat storage material and warm water to efficiently exchange heat, and also establish technology for enclosing heat storage material with balancing both durability for repeated use and heat transmission performance. And we will move forward to practical use.

Also we are working on developing technology for expanding the range of usage temperatures for heat storage materials and on opening up applications for them. In this way, we will contribute to further energy conservation.