Vol. 54 No. 2 (2017)   Air-Conditioning & Refrigeration
Technical Papers

Centrifugal Chiller System Using ATES (Aquifer Thermal Energy Storage) of Renewable Energy

MASANOBU SAKAI
LINRI CUI
TAKESHI FUCHIMOTO
KIYOKAZU TSUJI
KENJI UEDA

This report introduces Aquifer Thermal Energy Storage (ATES) systems, which utilize renewable geothermal energy. Beneath our feet lies plenty of groundwater stored unused. When compared with the outside air temperature, groundwater is warmer in the winter and cooler in the summer, and therefore is of high value as a heat source or heat sink (cold source). Mitsubishi Heavy Industries Thermal Systems, Ltd. has constructed a heat/cold source system for heating/cooling by using a centrifugal chiller and aquifers with a very low flow of groundwater. The system is comprised of (1) the centrifugal chiller, (2) pumping wells, (3) cold/hot water pumps, and (4) the heat exchanger. Currently in test operation at the time of report publication (April 2017), the system has achieved a coefficient of performance (COP) of 4.77 while heating in the winter with an average outside air wet-bulb temperature (WBT) of 0.15°C.