Heating Assist System for Liquid Tank Using Shallow Geothermal Energy via Heat Pipe BACH

Abstract

This study aims to develop a heating assist system for liquid tanks by using shallow geothermal energy via a new type of heat pipe named Bubble-Actuated Circulating Heat pipe (BACH). In this system, BACH transports heat from shallow underground (temperature remains constant at around 15 °C in Fukui) to the liquid of caustic soda solution (49 wt%, freezing point is about 5 °C) preserved in the tank. From a previous simplified small-scale experiment, we concluded that BACH could warm the liquid to some extent in winter. In this report, experimental results of field tests are demonstrated where 10 m³ tank equipped with an electric heater as an auxiliary heater was tested and five sets of BACH were installed. As a result, this system could warm the liquid at about 7 °C only by BACH without electricity under the experimental conditions tested.