Field experiments of the thermal storage utilizing aquifer. Improvement in thermal recovery factor and payback of the investment.
Hiromichi Umemiya, Susumu SHIMAWAKI, Hirokazu Kobayashi · TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series B · 1988
For the thermal energy storage in an aquifer, the investigation of the structure of stratum at a moderate price is very difficult. Hence a field experiment is necessary to understand the general trend. A study of the thermal energy storage in an aquifer has been carried out on our site for 5 cycle. The experimental results showed the following. I) In the 5th cycle, the thermal recovery factor is expected to be 60%. II) IN the 5th cycle, the structure of the charge well was improved, reducing the heat losses from the casing pipe. The heat losses during charge were reduced to 2/5 of the previous one. III) The coefficient of performance of our solar system, based on the thermal storage utilizing aquifer, was 10.1. IV) The payback of the investment is 10 years when the recovery factor is 60% and the pump efficiency is 60%.