FIELD: heat-and-power engineering.
SUBSTANCE: invention relates to heat engineering and can be used in underground heat energy accumulators. Underground accumulator comprises well and at least one tunnel, connected to each other with provision of communication. Tunnel has at least three sections. Second section of tunnel is arranged between first and third sections, is connected to them and plugged with end of which is interfaced with third section, which is also connected to well. Well first and third sections of tunnel are configured for movement of fluid medium therein for heat accumulation. Second section of tunnel is configured to use expansion chamber to receive fluid volume exceeding volume of well, first and third sections of tunnel. Accumulator is additionally equipped with first carrying device for temporary transfer of excess volume of fluid from well and/or third section of tunnel into first section of tunnel.
EFFECT: further, accumulator has second transfer means for transfer of excess volume of fluid medium from first section of tunnel into second section of tunnel.
8 cl, 2 dwg
