Arrangement in a heat pump plant

DETAILED DESCRIPTION I claim: 1.
A heat pump of the type including an evaporator, a compressor, a condenser, said condenser having a built-in subcooler and an expansion valve forming a refrigerant circuit, further comprising: a water heating pump having one end connected to said condenser heating medium outlet side; an ejector having first, second and third ports, said first port connected to a remaining end of said water heating pump through a non-return valve; a hot gas heat exchanger connected between the compressor and condenser inlet, said heat exchanger having a heating medium side with an outlet connected to said ejector second port, and an inlet; a second subcooler connected between an outlet of said built-in subcooler and said expansion valve, said second subcooler having a heating medium side connected to a separate heating circuit; and a domestic water heater having an inlet connected to said ejector third port, and an outlet connected to said hot gas heat exchanger inlet and said built-in subcooler inlet.
2.
The apparatus of claim 1 further comprising: a water temperature sensing means; means connected to said water temperature means and said water pump for providing a flow of water to said ejector when the water temperature is below a predetermined level; a radiator heating pump connected between a radiator circuit and said condenser outlet; a second temperature sensing means for monitoring said radiator circuit water temperature; means connected to said second temperature sensing means for operating said radiator heating pump when said radiator water temperature is below a predetermined level; and a pump connected to the cooling medium side of said evaporator, said pump connected to operate when either of said radiator heating pump or said water heating pump is operating.
3.
The heat pump of claim 1 further comprising: means for arranging priority between operation of said domestic water heating pump and said radiator heating pump, whereby said radiator heating pump is maintained out of operation until a certain domestic hot water temperature is reached, and thereafter enabled until a predetermined radiator water temperature is reached