Heat pump refrigeration circuit with liquid heating capability

A liquid heating module for use in combination with a heat pump circuit used to selectively heat or cool a space, where said heat pump circuit includes a compressor, an indoor unit including a heat exchanger, and an outdoor unit including a heat exchanger, said indoor and said outdoor unit heat exchangers being connected by a refrigerant liquid line, said module comprising:

• means for exchanging heat between a refrigerant and a liquid, said refrigerant-liquid heat exchange means interposed in said refrigerant liquid line to provide an uninterrupted flow path for refrigerant between said inside and said outside heat exchange units;
• a refrigerant charge reservoir;
• and
• valve means connected to said refrigerant-liquid heat exchange means, to said refrigerant charge reservoir, and to the suction port of said heat pump compressor, for selectively providing either a first refrigerant flow path or a second refrigerant flow path, said first refrigerant flow path connecting said refrigerant-liquid heat exchange means with said charge reservoir and said second refrigerant flow path connecting said reservoir with the suction port of said heat pump compressor.

A refrigerant circuit comprising:

• means for compressing a refrigerant vapor, said compressor means having a suction port and a discharge port;
• first selectively activated heat exchange means, for transferring heat between a refrigerant and air circulated within an indoor space;
• second selectively activated heat exchange means for transferring heat between a refrigerant and a heat transfer medium;
• third selectively activated heat exchange means, for transferring heat between a refrigerant and a liquid;
• a refrigerant charge reservoir;
• and
• conduit means, including selectively positionable valve means, for directing the flow of refrigerant within said circuit in
• i. a space heating mode wherein said charge reservoir is vented to said suction port of said compressor means and wherein said compressor discharges refrigerant to said first heat exchange means, said refrigerant thence being directed through said third heat exchange means and through said second heat exchange means and returned to said suction port of said compressor means, said first and second heat exchange means being activated and said third heat exchange means being inactivated in said space heating mode;
• ii. a space cooling mode wherein said charge reservoir is vented to said suction port of said compressor means and wherein said compressor discharges refrigerant to said second heat exchange means, said refrigerant thence being directed through said third heat exchange means and through said first heat exchange means and returned to said suction port of said compressor means, said first and second heat exchange means being activated and said third heat exchange means being inactivated in said space cooling modes;
• iii. a liquid heating mode wherein said compressor means discharges refrigerant to said first heat exchange means, said refrigerant thence being directed to said third heat exchange means for condensation therein, a first predetermined portion of said condensed refrigerant being directed to said refrigerant charge reservoir and a second predetermined portion of said condensed refrigerant being directed to said second heat exchange means for vaporization therein and return to said suction port of said compressor means, said second and said third heat exchange means being activated and said first heat exchange means being inactivated in said liquid heating mode;
• iv. a simultaneous space cooling and liquid heating mode wherein said compressor means discharges refrigerant to said second heat exchange means, said refrigerant thence being directed to said third heat exchange means for condensation therein, a first predetermined portion of said condensed refrigerant being directed to said refrigerant charge reservoir and a second predetermined portion of said condensed refrigerant being directed to said first heat exchange means for vaporization therein and return to said suction port of said compressor means, said first and said third exchange means being activated and said second heat exchange means being inactivated in said simultaneous space cooling and liquid heating mode.