High performance heat pump unit

Abstract

A heat pump unit ( 1 ) comprises at least one main circuit ( 2 ) adapted to perform a main heat pump cycle with a respective operating fluid, which comprises: a main condenser (S 4 ) adapted to perform the condensation of the operating fluid of the main heat pump cycle and intended to be connected to an external circuit of a first thermal user plant ( 10 ) in a heating operating mode of said heat pump unit ( 1 ); a first heat exchanger (S 3 ), connected downstream of the main condenser (S 4 ) and upstream of expansion means (L 2 ) of said the main circuit ( 2 ), adapted to perform an undercooling of the operating fluid of the main heat pump cycle after the condensation of the same in the main condenser (S 4 ), and a main evaporator (S 8 ) adapted to perform the evaporation of the operating fluid of the main heat pump cycle and intended to be connected to an external circuit of a heat sink ( 20 ) in a heating operating mode of said heat pump unit ( 1 ). The first heat exchanger (S 3 ) is selectively connectable to the external circuit of the first thermal user plant ( 10 ) so as to be in series with the main condenser (S 4 ) in said external circuit.

1 . Heat pump unit comprising at least one main circuit adapted to perform a main heat pump cycle with a respective operating fluid, said at least one main circuit comprising:
 a main condenser adapted to perform the condensation of the operating fluid of said main heat pump cycle and intended to be connected to an external circuit of a first thermal user plant in a heating operating mode of said heat pump unit;   a first heat exchanger, connected downstream of said main condenser and upstream of expansion means of said at least one main circuit, adapted to perform an undercooling of the operating fluid of said main heat pump cycle after the condensation of the same in said main condenser, and   a main evaporator adapted to perform the evaporation of the operating fluid of said main heat pump cycle and intended to be connected to an external circuit of a heat sink in a heating operating mode of said heat pump unit,   
       characterized in that said first heat exchanger is selectively connectable to the external circuit of said first thermal user plant so as to be in series with said main condenser in said external circuit. 
     
     
         2 . Heat pump unit according to  claim 1 , wherein said main circuit comprises a first sub-circuit adapted to perform a higher temperature main heat pump cycle with a respective operating fluid and a second sub-circuit adapted to perform a lower temperature main heat pump cycle with a respective operating fluid, wherein said first and second sub-circuits are in cascading heat exchange relationship with each other so as to perform globally a two-stage main heat pump cycle, and wherein said main condenser and said first heat exchanger are connected in said first sub-circuit and said main evaporator is connected in said second sub-circuit. 
     
     
         3 . Heat pump unit according to  claim 2 , wherein said second sub-circuit comprises a second heat exchanger connected downstream of a condenser and upstream of expansion means of said second sub-circuit, said second heat exchanger being adapted to perform an undercooling of the operating fluid of said lower temperature main heat pump cycle after the condensation thereof and being selectively connectable to the external circuit of said heat sink so as to perform a preheating of a heat carrier fluid coming from said heat sink by means of heat power released during said undercooling by the operating fluid of said lower temperature main heat pump cycle. 
     
     
         4 . Heat pump unit according to  claim 3 , wherein said second heat exchanger is further selectively connected to an external circuit of a second thermal user plant. 
     
     
         5 . Heat pump unit according to  claim 3 , wherein said first sub-circuit comprises a third heat exchanger connected downstream of said first heat exchanger and upstream of expansion means of said first sub-circuit, said third heat exchanger being adapted to perform an undercooling of the operating fluid of said higher temperature main heat pump cycle after the condensation thereof and being selectively connectable to the external circuit of said heat sink so as to perform, preferably independently from said second heat exchanger, a preheating of a heat carrier fluid coming from said heat sink by means of heat power released during said undercooling by the operating fluid of said upper temperature main heat pump cycle. 
     
     
         6 . Heat pump unit according to  claim 5 , wherein said third heat exchanger is further selectively connectable to the external circuit of said second thermal user plant. 
     
     
         7 . Heat pump unit according to  claim 2 , comprising a fourth heat exchanger connected downstream of said main condenser and upstream of said third heat exchanger, said fourth heat exchanger being adapted to perform an undercooling of the operating fluid of said higher temperature main heat pump cycle after the condensation of the same, and a secondary circuit adapted to perform a secondary heat pump cycle with a respective operating fluid, said secondary circuit comprising:
 a secondary evaporator adapted to perform at least the evaporation of the operating fluid of said secondary heat pump cycle and in heat exchange relationship with said fourth heat exchanger to transfer heat power released by the operating fluid of said main heat pump cycle during said undercooling to the operating fluid of said secondary heat pump cycle;   a secondary condenser adapted to perform the condensation of the operating fluid of said secondary heat pump cycle and intended to be connected to the external circuit of said first thermal user plant or to an external circuit of a third thermal user plant, different from said first and second thermal user plants.   
     
     
         8 . Heat pump unit according to  claim 1 , comprising switching means, adapted to allow an exchange of connections of the external circuits of at least said first thermal user plant and said heat sink respectively with at least said main condenser and with said main evaporator 
     
     
         9 . Heat pump unit according  claim 1 , wherein the operating fluid of said main heat pump cycle, or the operating fluids of said higher temperature main heat pump cycle and of said lower temperature main heat pump cycle respectively, and the operating fluid of said secondary heat pump cycle are selected from the group consisting of: (E)-2-butene, (Z)-2-butene, 1-butylene, dimethyl ketone, methylacetylene, methyl alcohol, methylpentane, methylpropene, n-hexane, R1270, R290, R600, R600a, R601, R601a, RE-170, tetramethylmethane or RC-270. 
     
     
         10 . Heat pump unit according to  claim 1 , comprising means for detecting and evacuating gas leaks. 
     
     
         11 . System for heating/cooling environments and/or for producing sanitary hot water comprising a heat pump unit according to  claim 1 . 
     
     
         12 . Heat pump unit according to  claim 4 , wherein said first sub-circuit comprises a third heat exchanger connected downstream of said first heat exchanger and upstream of expansion means of said first sub-circuit, said third heat exchanger being adapted to perform an undercooling of the operating fluid of said higher temperature main heat pump cycle after the condensation thereof and being selectively connectable to the external circuit of said heat sink so as to perform, preferably independently from said second heat exchanger, a preheating of a heat carrier fluid coming from said heat sink by means of heat power released during said undercooling by the operating fluid of said upper temperature main heat pump cycle. 
     
     
         13 . Heat pump unit according to  claim 12 , wherein said third heat exchanger is further selectively connectable to the external circuit of said second thermal user plant.