Refrigerant charge management systems and methods

Abstract

The present disclosure relates to a passive refrigerant charge management system including a charge vessel configured to fluidly couple to a refrigerant circuit. The charge vessel includes a first portion having a compressible fluid and a second portion configured to contain refrigerant of the refrigerant circuit, wherein an amount of the refrigerant contained in the second portion is based on a first pressure of the refrigerant within the refrigerant circuit and a second pressure of the compressible fluid.

1 . A passive refrigerant charge management system, comprising:
 a charge vessel configured to fluidly couple to a refrigerant circuit, wherein the charge vessel comprises:
 a first portion comprising a compressible fluid; and 
 a second portion configured to contain refrigerant of the refrigerant circuit, wherein an amount of the refrigerant contained in the second portion is based on a first pressure of the refrigerant within the refrigerant circuit and a second pressure of the compressible fluid. 
   
     
     
         2 . The passive refrigerant charge management system of  claim 1 , wherein the second portion is configured to fluidly couple to a liquid refrigerant portion of the refrigerant circuit. 
     
     
         3 . The passive refrigerant charge management system of  claim 1 , wherein the charge vessel comprises a flexible divider disposed between the first portion and the second portion, and wherein the flexible divider fluidly separates the first portion and the second portion. 
     
     
         4 . The passive refrigerant charge management system of  claim 3 , wherein the flexible divider comprises a bladder, and wherein the bladder contains the compressible fluid. 
     
     
         5 . The passive refrigerant charge management system of  claim 1 , wherein the charge vessel comprises a sensor configured to measure a fluid pressure within the charge vessel. 
     
     
         6 . The passive refrigerant charge management system of  claim 1 , wherein the compressible fluid comprises an inert gas. 
     
     
         7 . The passive refrigerant charge management system of  claim 1 , wherein the second portion of the charge vessel is configured to hold 10 to 20 percent of a total refrigerant charge of the refrigerant circuit. 
     
     
         8 . The passive refrigerant charge management system of  claim 1 , wherein the charge vessel is configured to passively remove refrigerant charge from the refrigerant circuit as an ambient temperature increases and to passively add refrigerant charge to the refrigerant circuit as the ambient temperature decreases. 
     
     
         9 . A heating, ventilation, and air conditioning (HVAC) system, comprising:
 a refrigerant circuit configured to flow a refrigerant; and   a charge vessel fluidly coupled to the refrigerant circuit, wherein the charge vessel is configured to passively adjust a refrigerant charge level of the refrigerant circuit based on a pressure of the refrigerant within the refrigerant circuit.   
     
     
         10 . The HVAC system of  claim 9 , comprising an indoor HVAC unit and an outdoor HVAC unit, wherein the outdoor HVAC unit comprises the charge vessel. 
     
     
         11 . The HVAC system of  claim 9 , wherein the charge vessel comprises a shell and a bladder disposed within the shell. 
     
     
         12 . The HVAC system of  claim 9 , wherein the charge vessel is fluidly coupled to a liquid refrigerant portion of the refrigerant circuit, wherein the liquid refrigerant portion is configured to flow substantially liquid refrigerant during operation of the HVAC system. 
     
     
         13 . The HVAC system of  claim 9 , wherein the charge vessel comprises a first section comprising a compressible fluid, and wherein the charge vessel comprises a second section fluidly coupled to the refrigerant circuit, wherein the first section and second section are fluidly separate from one another. 
     
     
         14 . The HVAC system of  claim 9 , wherein the charge vessel comprises a flexible bladder configured to deform in response to the pressure of the refrigerant. 
     
     
         15 . The HVAC system of  claim 9 , wherein the charge vessel is configured to automatically accept refrigerant from the refrigerant circuit as the pressure increases and automatically discharge refrigerant to the refrigerant circuit as the pressure decreases. 
     
     
         16 . The HVAC system of  claim 9 , comprising a heat pump system, wherein the heat pump system comprises the refrigerant circuit. 
     
     
         17 . The HVAC system of  claim 9 , comprising an air conditioning system, wherein the air conditioning system comprises the refrigerant circuit. 
     
     
         18 . A heating, ventilation, and air conditioning (HVAC) system, comprising:
 a refrigerant loop;   a condenser disposed along the refrigerant loop and configured to condense refrigerant of the refrigerant loop; and   a charge vessel disposed along the refrigerant loop and configured to passively adjust a refrigerant charge of the refrigerant loop based on a discharge pressure of the refrigerant from the condenser.   
     
     
         19 . The HVAC system of  claim 18 , wherein the charge vessel is fluidly coupled to the refrigerant loop at a location along the refrigerant loop where the refrigerant at the location is substantially liquid. 
     
     
         20 . The HVAC system of  claim 18 , wherein the charge vessel comprises a bladder configured to passively flex to adjust the refrigerant charge of the refrigerant loop. 
     
     
         21 . The HVAC system of  claim 18 , wherein the charge vessel comprises a fluidly isolated portion configured to adjust in volume in response to the discharge pressure. 
     
     
         22 . The HVAC system of  claim 18 , wherein the charge vessel comprises a section isolated from the refrigerant loop, wherein the section comprises a compressible fluid. 
     
     
         23 . The HVAC system of  claim 22 , wherein the compressible fluid comprises an inert gas. 
     
     
         24 . The HVAC system of  claim 18 , wherein the charge vessel is configured to passively remove refrigerant charge from the refrigerant loop as an ambient temperature increases and to passively add refrigerant charge to the refrigerant loop as the ambient temperature decreases.