Double Hybrid Heat Pumps and Systems and Methods of Use and Operations

Abstract

Double hybrid heat pumps, systems, and methods of operation that provide increased efficiency in both heating and cooling modes, heated water, and other advantages. The system includes a compressor compresses low-pressure vapor phase refrigerant to high-pressure, a refrigerant condensing heat exchanger condenses the refrigerant to a high-pressure liquid refrigerant, a refrigerant cooling heat exchanger subcools the condensed high-pressure liquid refrigerant. The high-pressure subcooled liquid refrigerant is further subcooled in a refrigerant-to-refrigerant heat exchanger, then expanded through an expansion device to yield low-pressure cooled liquid refrigerant or low-pressure cooled two-phase refrigerant. The low-pressure cooled liquid or two-phase refrigerant is then evaporated in a refrigerant evaporating heat exchanger to produce the low-pressure vapor refrigerant that is heated via the refrigerant-to-refrigerant heat exchanger and returned to the compressor.

What is claimed is: 
     
         1 . A heat pump system comprising:
 a compressor having a low-pressure vapor refrigerant inlet and a high-pressure vapor refrigerant outlet, the compressor configured to compress a low-pressure vapor refrigerant passing from the inlet to the outlet of the compressor into a high-pressure vapor refrigerant;   a refrigerant condensing heat exchanger having an inlet connected to the high-pressure vapor refrigerant outlet of the compressor and an outlet, the condensing heat exchanger configured to condense high-pressure vapor refrigerant passing from the inlet to the outlet of the condensing heat exchanger and exchange heat from the refrigerant to heat water;   a refrigerant cooling heat exchanger having an inlet connected to outlet of the condensing heat exchanger and an outlet, the cooling heat exchanger configured to condense high-pressure vapor refrigerant and further cool the high-pressure liquid refrigerant passing from the inlet to the outlet of the cooling heat exchanger;   a refrigerant-to-refrigerant heat exchanger positioned to transfer heat from the high-pressure liquid refrigerant to low-pressure vapor refrigerant;   an expansion device having an inlet connected to the outlet of the refrigerant-to-refrigerant heat exchanger outlet and an outlet, the expansion device configured to induce a pressure drop in the high-pressure liquid refrigerant passing through the expansion device and output one of a low-pressure liquid and a two-phase vapor/liquid mixture refrigerant;   a liquid receiver positioned between the refrigerant condensing heat exchanger and the expansion device and configured to contain high-pressure liquid refrigerant and allow relative inflows and outflows of the high-pressure liquid refrigerant from the liquid receiver, the system having a refrigerant charge suitable to fill piping and heat exchangers downstream of the liquid receiver with liquid refrigerant; and   a refrigerant evaporating heat exchanger having an inlet connected to the expansion device outlet and an outlet, the evaporating heat exchanger configured to at least vaporize low-pressure liquid refrigerant passing from the inlet to the outlet of the evaporating heat exchanger and provide the low-pressure vapor refrigerant to the refrigerant-to-refrigerant heat exchanger, where   the evaporating heat exchanger cools a secondary fluid when the system is in a cooling mode and the refrigerant cooling heat exchanger heats the secondary fluid when the system is in a heating mode.   
     
     
         2 . The system of  claim 1 , where the refrigerant-to-refrigerant heat exchanger has an outlet connected to provide the low-pressure vapor to the compressor low-pressure vapor refrigerant inlet. 
     
     
         3 . The system of  claim 1 , where the evaporating heat exchanger in the heating mode and the refrigerant cooling heat exchanger in the cooling mode comprises a refrigerant-to-source heat exchanger. 
     
     
         4 . The system of  claim 1 , where the refrigerant cooling heat exchanger in the heating mode and the refrigerant evaporating heat exchanger in the cooling mode comprises a refrigerant-to-secondary fluid heat exchanger. 
     
     
         5 . The system of  claim 4 , where the refrigerant-to-secondary fluid heat exchanger comprises a plurality of refrigerant-to-air heat exchangers including at least one blower to pass air over the heat exchangers and provide cooled air in the cooling mode and heated air in the heating mode. 
     
     
         6 . The system of  claim 4 , where the refrigerant-to-secondary fluid heat exchanger comprises a plurality of refrigerant-to-secondary heat exchangers. 
     
     
         7 . The system of  claim 1 , further comprising a second liquid receiver positioned downstream of the expansion device configured to contain low-pressure liquid refrigerant and allow relative inflows and outflows of the low-pressure liquid refrigerant from the second liquid receiver. 
     
     
         8 . The system of  claim 1 , further comprising
 a first reversing element configured to reverse the refrigerant flow between the heating and cooling mode, where
 in the heating mode, the cooling heat exchanger is a refrigerant to air heat exchanger and the refrigerant evaporating heat exchanger is a refrigerant to source heat exchanger, and where 
 in the cooling mode, the cooling heat exchanger is the refrigerant to source heat exchanger and the refrigerant evaporating heat exchanger is the refrigerant-air heat exchanger. 
   
     
     
         9 . The system of  claim 1 , further comprising
 a first reversing element configured to reverse the refrigerant flow between the heating and cooling mode; and   a second reversing element configurable in a first configuration to direct flow through the liquid receiver to the cooling heat exchanger and in a second configuration to direct flow through the cooling heat exchanger to the liquid receiver.   
     
     
         10 . The system of  claim 1 , where
 the liquid receiver is positioned between the refrigerant condensing heat exchanger and the refrigerant cooling heat exchanger.   
     
     
         11 . The system of  claim 1 , where
 the liquid receiver is positioned between immediately upstream of the refrigerant-to-refrigerant heat exchanger.   
     
     
         12 . A heat pump system comprising:
 a compressor having a low-pressure vapor refrigerant inlet and a high-pressure vapor refrigerant outlet, the compressor configured to compress a low-pressure vapor refrigerant passing from the inlet to the outlet of the compressor into a high-pressure vapor refrigerant;   a refrigerant condensing heat exchanger having an inlet connected to the high-pressure vapor refrigerant outlet of the compressor and an outlet, the condensing heat exchanger configured to condense high-pressure vapor refrigerant passing from the inlet to the outlet of the condensing heat exchanger and exchange heat from the refrigerant to heat water;   a refrigerant cooling heat exchanger having an inlet connected to outlet of the condensing heat exchanger and an outlet, the cooling heat exchanger configured to condense any high-pressure vapor refrigerant output from the condensing heat exchanger and further subcool the high-pressure liquid refrigerant passing from the inlet to the outlet of the cooling heat exchanger;   an expansion device having an inlet connected to the outlet of the cooling heat exchanger outlet and an outlet, the expansion device configured to induce a pressure drop in the high-pressure liquid refrigerant passing through the expansion device and output one of a low-pressure liquid and a two-phase vapor/liquid mixture refrigerant;   a liquid receiver positioned between the refrigerant condensing heat exchanger and the refrigerant cooling heat exchanger and configured to contain high-pressure liquid refrigerant and allow relative inflows and outflows of the high-pressure liquid refrigerant from the liquid receiver, the system having a refrigerant charge suitable to fill piping and heat exchangers downstream of the liquid receiver with liquid refrigerant; and   a refrigerant evaporating heat exchanger having an inlet connected to the expansion device outlet and an outlet, the evaporating heat exchanger configured to at least vaporize low-pressure liquid refrigerant passing from the inlet to the outlet of the evaporating heat exchanger and provide the low-pressure vapor refrigerant to the compressor inlet, where   the evaporating heat exchanger cools a secondary fluid when the system is in a cooling mode and the refrigerant cooling heat exchanger heats the secondary fluid when the system is in a heating mode.   
     
     
         13 . The system of  claim 12 , where the refrigerant cooling heat exchanger in the heating mode and the refrigerant evaporating heat exchanger in the cooling mode comprises a refrigerant-to-secondary fluid heat exchanger. 
     
     
         14 . The system of  claim 13 , where the refrigerant-to-secondary fluid heat exchanger comprises a plurality of refrigerant-to-air heat exchanger including at least one blower to pass air over the heat exchanger and provide cooled air in the cooling mode and heated air in the heating mode. 
     
     
         15 . The system of  claim 12 , further comprising
 a refrigerant-to-refrigerant heat exchanger positioned to transfer heat from the high-pressure liquid refrigerant to low-pressure vapor refrigerant.   
     
     
         16 . The system of  claim 15 , further comprising
 a first reversing element configured to reverse the refrigerant flow between the heating and cooling mode; and   a second reversing element configurable in a first configuration to direct flow through the liquid receiver to the cooling heat exchanger and in a second configuration to direct flow through the cooling heat exchanger to the liquid receiver.   
     
     
         17 . A method of providing heated or cooled air and heated water, comprising:
 compressing, by a compressor, a low-pressure vapor refrigerant to high-pressure vapor refrigerant;   condensing, by a refrigerant condensing heat exchanger, the high-pressure vapor refrigerant to a high-pressure liquid refrigerant to transfer heat to water;   subcooling, via a refrigerant cooling heat exchanger, the high-pressure liquid refrigerant;   subcooling, via a refrigerant to refrigerant heat exchanger, further the subcooled high-pressure liquid refrigerant;   expanding, via an expansion device, the further subcooled high-pressure liquid refrigerant to produce a low-pressure cooled liquid refrigerant; and   providing a liquid receiver between the refrigerant condensing heat exchanger and expansion device to receive high-pressure liquid refrigerant;   evaporating, via a refrigerant evaporating heat exchanger, the low-pressure cooled liquid refrigerant to provide the low-pressure vapor refrigerant to the compressor, where   the evaporating heat exchanger provides cool air in the cooling mode and the refrigerant cooling heat exchanger provides heated air in the heating mode.   
     
     
         18 . The method of  claim 17 , where
 the liquid receiver is positioned between the refrigerant condensing heat exchanger and one of the refrigerant cooling heat exchanger and the refrigerant-to-refrigerant heat exchanger.   
     
     
         19 . The method of  claim 17 , where the refrigerant cooling heat exchanger in the heating mode and the refrigerant evaporating heat exchanger in the cooling mode comprises a refrigerant-to-secondary fluid heat exchanger. 
     
     
         20 . The method of  claim 17 , where the refrigerant cooling heat exchanger comprises a plurality of refrigerant-to-air heat exchangers including at least one blower to pass air over the heat exchangers and provide cooled air in the cooling mode and heated air in the heating mode.