Thermal storage heat exchanger systems of heat pumps

Claim 1

In a heat pump having a heat source, a heat sink and a thermal storage heat exchanger in which heat energy is cyclically accumulated and discharged by circulation of a secondary refrigerant therethrough, the improvement wherein: (i) the secondary refrigerant is an aqueous solution having a concentration which is below its eutetic concentration, (ii) the heat sink is adapted to super cool the aqueous solution to partially freeze it to generate a partially frozen solution in which fine ice particles are retained in suspension in a liquid secondary refrigerant, (iii) the thermal storage heat exchanger has a storage chamber which is divided by a porous divider, into a first and second enclosures, said heat sink having an intake line communicating with said first enclosure for withdrawing liquid secondary refrigerant therefrom and an output communicating with said second enclosure for discharging said partially frozen secondary refrigerant into said second enclosure wherein said ice particles separate from the liquid to form a porous ice bed and a substantially ice free liquid bath, said heat source having an intake communicating with said first enclosure through which liquid secondary refrigerant is withdrawn from said chamber and an output communicating with said second enclosure through which heated liquid secondary refrigerant is discharged into said second enclosure such that it is placed in intimate contact with the ice bed in a manner such that it may pass through the pores of the porous ice bed prior to its return to the bath.