Heat and cold storage tank with counterflow heat exchanger

A heat storage and exchanger comprising:

• a first fluid conduit and a second fluid conduit;
• a heat exchanger configured to transfer heat between the first fluid conduit and the second fluid conduit;
• and
• a storage tank configured to receive a thermal storage medium;
• wherein at least a section of the heat exchanger is arranged in the storage tank to enable a transfer of heat between the heat exchanger and the thermal storage medium.

A system comprising:

• a first heat storage and exchanger and a second heat storage and exchanger, wherein the first heat storage and exchanger comprises:
• a first fluid conduit and a second fluid conduit;
• a heat exchanger configured to transfer heat between the first fluid conduit and the second fluid conduit;
• and
• a storage tank configured to receive a thermal storage medium, wherein:
• at least a section of the heat exchanger is arranged in the storage tank to enable a transfer of heat between the heat exchanger and the thermal storage medium;
• and
• the first heat storage and exchanger has a volume for its thermal storage medium of at least 2 m2 and is arranged at least partially underground;
• and
• the second heat storage and exchanger comprises:
• a first fluid conduit and a second fluid conduit;
• and
• a storage tank configured to receive a thermal storage medium, wherein:
• the second heat storage and exchanger is configured to enable a transfer of heat between the first fluid conduit and the thermal storage medium and between the second fluid conduit and the thermal storage medium;
• a heat pump configured to provide a power of at least 5 kW, wherein:
• a fluid flow through the first fluid conduit of one of the first and second heat storage and exchangers is configured to thermally couple that heat storage and exchanger to a cold side of the heat pump;
• and
• a fluid flow through the first fluid conduit of the other heat storage and exchanger is configured to thermally couple the other heat storage and exchanger to a warm side of the heat pump;
• and
• a controller configured to control an operating state of the heat pump, the fluid flow through the first fluid conduit of the first heat storage, and the fluid flow through the first fluid conduit of the second heat storage together in dependence on a first parameter, wherein the first parameter is associated with an electrical power provided by a photovoltaic system;
• wherein the second fluid conduit of at least one of the first heat storage and exchanger and the second heat storage and exchanger is coupled to a solar system.

A method of operating a system comprising a heat storage and exchanger, wherein the heat storage and exchanger comprises:

• a first fluid conduit and a second fluid conduit, wherein the first fluid conduit is coupled to a heat pump;
• a heat exchanger configured to transfer heat between the first fluid conduit and the second fluid conduit;
• and
• a storage tank configured to receive a thermal storage medium;
• wherein at least a section of the heat exchanger is arranged in the storage tank to enable a transfer of heat between the heat exchanger and the thermal storage medium;
• wherein the method comprises at least two modes of operation, the method comprising:
• selectively executing one of the at least two modes of operation;
• wherein the first mode of operation comprises:
• operating the heat pump at a first heat pump power;
• and
• generating a fluid flow through the first fluid conduit to transfer heat between the heat pump and the thermal storage medium;
• and
• wherein the second mode of operation comprises:
• operating the heat pump at a second heat pump power that is at most a quarter of the first heat pump power;
• and
• generating a stronger fluid flow through the second fluid conduit than through the first fluid conduit to transfer heat via the second fluid conduit.