Refrigerant accumulator

Abstract

An refrigerant accumulator ( 18 ) comprises a first chamber ( 30 ), a second chamber ( 32 ), a pre-evaporator line ( 34 ), a post-evaporator-inlet line ( 36 ), and a post-evaporator-outlet line ( 38 ). The chambers ( 30, 32 ) are in a pressure-isolated arrangement and a heat-transfer relationship. The pre-evaporator line ( 34 ) passes through and communicates with the first chamber ( 30 ). In a steady state, the pressure of fluid in the first chamber ( 30 ) is greater than the pressure of fluid in the second chamber ( 32 ), but their temperatures are the same, and the pressure of fluid within the first chamber is balanced with the pressure of fluid within the pre-evaporator line. In a starved or flooded state, temperature differentials between the chamber ( 30 ) and chamber ( 32 ), and pressure imbalances between the chamber ( 30 ) and the pre-evaporator line ( 34 ), adjust the charge of refrigerant fluid to return the system to a steady state.

1 . An accumulator for a refrigeration system, comprising: 
 a first chamber and a second chamber, the chambers being in a pressure-isolated arrangement, whereby the pressure of fluid in one chamber does not equalize to the pressure of fluid in the other chamber, and being in a heat-transfer relationship, whereby the temperature of fluid in one chamber equalizes with the temperature of the fluid in the other chamber;    a pre-evaporator line forming a flow passage which passes through and communicates with the first chamber, whereby the pressure of fluid within the first chamber equalizes with the pressure of fluid within the pre-evaporator line;    a post-evaporator-inlet line forming a flow passage into the second chamber; and    a post-evaporator-outlet line forming a flow passage out of the second chamber.    
   
   
       2 . An accumulator as set forth in  claim 1 , wherein the pre-evaporator line includes at least one interchange opening for communication between fluid within the first chamber and fluid within the pre-evaporator line.  
   
   
       3 . An accumulator as set forth in  claim 2 , wherein the interchange opening(s) each have a flow area substantially less than the flow area of the pre-evaporator inlet line.  
   
   
       4 . An accumulator as set forth in  claim 1 , wherein the pre-evaporator line includes at two interchange openings for communication between fluid within the first chamber and fluid within the pre-evaporator line, and wherein one of the interchange openings is positioned above the other of the interchange openings.  
   
   
       5 . An accumulator as set forth in  claim 1 , wherein the flow passage formed by the post-evaporator-outlet line is a gas-only flow passage.  
   
   
       6 . An accumulator as set forth in  claim 5 , wherein the post-evaporator-outlet line includes an open end positioned in an upper region of the second chamber and a drain opening in a lower region of the second chamber.  
   
   
       7 . An accumulator as set forth in  claim 1 , wherein the first chamber is positioned below the second chamber.  
   
   
       8 . An accumulator as set forth in  claim 1 , wherein the pre-evaporator line passes through, but does not communicate with, the second chamber.  
   
   
       9 . An accumulator as set forth in  claim 1 , wherein the pre-evaporator line includes a fixed orifice metering device upstream of the first chamber.  
   
   
       10 . An accumulator as set forth in  claim 1 , wherein the first chamber and the second chamber are formed by a capsule and a heat-transferring divider and wherein the divider separates space defined by the capsule into the first chamber and the second chamber.  
   
   
       11 . An accumulator as set forth in  claim 10 , wherein the capsule has an entrance for the pre-evaporator line, an exit for the pre-evaporator line, an entrance for the post-evaporator-inlet line, and an exit for the post-evaporator-outlet line.  
   
   
       12 . An accumulator as set forth in  claim 11 , wherein the capsule includes a fitting and wherein at least three of the entrance(s) and exit(s) are situated on the fitting.  
   
   
       13 . An accumulator as set forth in  claim 12 , wherein the pre-evaporator line passes through, but does not communicate with, the second chamber.  
   
   
       14 . An accumulator as set forth in  claim 13 , wherein the heat-transferring divider includes at least one opening through which the pre-evaporator line can pass to/from the first chamber.  
   
   
       15 . An accumulator as set forth in  claim 13 , wherein the heat-transferring divider includes an opening through which the pre-evaporator line can pass to the first chamber and an opening through which the pre-evaporator line can pass from the first chamber.  
   
   
       16 . An accumulator as set forth in  claim 12 , wherein the two entrances and the two exits are situated on the fitting.  
   
   
       17 . An accumulator as set forth in  claim 1 , wherein: 
 the first chamber and the second chamber are formed by a capsule and a heat-transferring divider;    the first chamber is positioned below the second chamber;    the pre-evaporator line includes at least one opening for communication between fluid within the first chamber and fluid within the pre-evaporator line, and each opening has a flow area substantially less than the flow area of the pre-evaporator line; and    the flow passage formed by the post-evaporator-outlet line is a gas-only flow passage.    
   
   
       18 . An accumulator as set forth in  claim 17 , wherein the pre-evaporator line includes at least two openings for communication between fluid within the first chamber and fluid within the pre-evaporator line, one opening being positioned in an upper region of the first chamber and the other opening being positioned within a lower region the first chamber.  
   
   
       19 . A refrigeration system comprising an evaporator, a condenser, a compressor, the accumulator set forth in  claim 1 , and refrigerant fluid flowing through lines between the evaporator, the condenser, the compressor and the accumulator; wherein said lines comprise: 
 a line from the condenser outlet to the accumulator's pre-evaporator line,    a line from the accumulator's pre-evaporator line to the evaporator inlet,    a line from the evaporator outlet to the accumulator's post-evaporator-inlet line, and    a line from the accumulator's post-evaporator-outlet line to the compressor.    
   
   
       20 . A refrigeration system as set forth in  claim 19 , wherein, in a steady state, refrigerant fluid within the first chamber is saturated and refrigerant fluid within the second chamber is superheated.