Pre-subcooler for a condenser

Abstract

A condenser of a heating, ventilation, air conditioning, and refrigeration (HVAC&R) system includes a shell configured to receive vapor heat transfer fluid and a condensing section. A first plurality of heat exchange tubes is configured to place the vapor heat transfer fluid in a heat exchange relationship with cooling fluid to produce liquid heat transfer fluid. The condenser includes a subcooling section having a second plurality of heat exchange tubes extending within the shell, where the second plurality of heat exchange tubes is configured to place the liquid heat transfer fluid in a heat exchange relationship with cooling fluid to subcool the liquid heat transfer fluid. The condenser includes a pre-subcooler disposed in the condensing section, where the pre-subcooler includes a trough configured to collect a portion of the liquid heat transfer fluid and direct the portion of the liquid heat transfer fluid to the subcooling section.

1 . A condenser of a heating, ventilation, air conditioning, and refrigeration (HVAC&R) system, comprising:
 a shell configured to receive vapor heat transfer fluid;   a condensing section comprising a first plurality of heat exchange tubes extending within the shell, wherein the first plurality of heat exchange tubes is configured to place the vapor heat transfer fluid in a heat exchange relationship with cooling fluid directed through the first plurality of heat exchange tubes to produce liquid heat transfer fluid from the vapor heat transfer fluid;   a subcooling section comprising a second plurality of heat exchange tubes extending within the shell, wherein the second plurality of heat exchange tubes is configured to place the liquid heat transfer fluid in a heat exchange relationship with cooling fluid directed through the second plurality of heat exchange tubes to subcool the liquid heat transfer fluid; and   a pre-subcooler disposed in the condensing section, wherein the pre-subcooler comprises a trough configured to collect a portion of the liquid heat transfer fluid and direct the portion of the liquid heat transfer fluid to the subcooling section.   
     
     
         2 . The condenser of  claim 1 , wherein the first plurality of heat exchange tubes comprises a first tube bundle and a second tube bundle vertically offset from the first tube bundle, wherein the trough is disposed vertically between the first tube bundle and the second tube bundle. 
     
     
         3 . The condenser of  claim 2 , wherein the condenser is configured to direct a first flow of cooling fluid from a first cooling fluid section into and through a first pass of heat exchange tubes, wherein the first pass of heat exchange tubes comprises the second plurality of heat exchange tubes and the second tube bundle. 
     
     
         4 . The condenser of  claim 3 , wherein the condenser is configured to direct the first flow of cooling fluid from the first pass of heat exchange tubes to a second pass of heat exchange tubes, wherein the second pass of heat exchange tubes comprises the first tube bundle. 
     
     
         5 . The condenser of  claim 4 , wherein the pre-subcooler comprises pre-subcooler heat exchange tubes extending within a basin of the trough, and the condenser is configured to direct a second flow of cooling fluid from the first cooling fluid section to the pre-subcooler heat exchange tubes. 
     
     
         6 . The condenser of  claim 5 , wherein the condenser is configured to direct the second flow of cooling fluid from the pre-subcooler heat exchange tubes to the second pass of heat exchange tubes. 
     
     
         7 . The condenser of  claim 1 , wherein the first plurality of heat exchange tubes comprises a first tube bundle and a second tube bundle, the trough is disposed between the first tube bundle and the second tube bundle, and the trough is configured to direct the portion of the liquid heat transfer fluid toward longitudinal ends of the second tube bundle and to block flow of the portion of the liquid heat transfer fluid toward a central portion of the second tube bundle. 
     
     
         8 . The condenser of  claim 1 , wherein the second plurality of heat exchange tubes comprises a first subcooler pass and a second subcooler pass, the condenser comprises a separation plate disposed between the first subcooler pass and the second subcooler pass, the first plurality of heat exchange tubes is configured to direct the liquid heat transfer fluid to the first subcooler pass, and the separation plate is configured to direct the liquid heat transfer fluid from the first subcooler pass to the second subcooler pass. 
     
     
         9 . The condenser of  claim 8 , wherein the trough is configured to direct the portion of the liquid heat transfer fluid toward longitudinal ends of the first subcooler pass. 
     
     
         10 . The condenser of  claim 8 , wherein the separation plate is a solid piece of material that does not include apertures formed therein. 
     
     
         11 . A method, comprising:
 directing vapor heat transfer fluid across a first plurality of heat exchange tubes of a condensing section of a condenser to place the vapor heat transfer fluid in a heat exchange relationship with cooling fluid directed through the first plurality of heat exchange tubes, wherein the first plurality of heat exchange tubes is configured to condense the vapor heat transfer fluid to produce liquid heat transfer fluid;   directing the liquid heat transfer fluid across a second plurality of heat exchange tubes of a subcooling section of the condenser to place the liquid heat transfer fluid in a heat exchange relationship with cooling fluid directed through the second plurality of heat exchange tubes, wherein the second plurality of heat exchange tubes is configured to subcool the liquid heat transfer fluid;   collecting, via a pre-subcooler disposed in the condensing section, a portion of the liquid heat transfer fluid condensed by a first tube bundle of the first plurality of heat exchange tubes; and   directing the portion of the liquid heat transfer fluid from the pre-subcooler toward longitudinal ends of a second tube bundle of the first plurality of heat exchange tubes.   
     
     
         12 . The method of  claim 11 , comprising blocking, via the pre-subcooler, flow of the portion of the liquid heat transfer fluid condensed by the first tube bundle of the first plurality of heat exchange tubes onto a central portion of the second tube bundle of the first plurality of heat exchange tubes. 
     
     
         13 . The method of  claim 11 , comprising:
 subcooling, via pre-subcooler tubes of the pre-subcooler, the portion of the liquid heat transfer fluid condensed by the first tube bundle of the first plurality of heat exchange tubes to produce subcooled liquid heat transfer fluid; and   directing the subcooled liquid heat transfer fluid toward the subcooling section.   
     
     
         14 . The method of  claim 11 , comprising:
 directing, from a first cooling fluid section to a second cooling fluid section, a flow of cooling fluid via the second plurality of heat exchange tubes and the second tube bundle of the first plurality of heat exchange tubes, wherein the second tube bundle comprises a group of heat exchange tubes of the first plurality of heat exchange tubes positioned vertically beneath the pre-subcooler, with respect to a direction of gravity; and   directing the flow of cooling fluid from the second cooling fluid section into and through the first tube bundle of the first plurality of heat exchange tubes, wherein the first tube bundle comprises an additional group of heat exchange tubes of the first plurality of heat exchange tubes positioned vertically above the pre-subcooler, with respect to the direction of gravity.   
     
     
         15 . The method of  claim 14 , comprising:
 directing, from the first cooling fluid section, an additional flow of cooling fluid through pre-subcooler tubes of the pre-subcooler and into the second cooling fluid section to mix the flow of cooling fluid and the additional flow of cooling fluid; and   directing, from the second cooling fluid section, the flow of cooling fluid and the additional flow of cooling fluid into and through the first tube bundle of the first plurality of heat exchange tubes.   
     
     
         16 . A condenser of a heating, ventilation, air conditioning, and refrigeration (HVAC&R) system, comprising:
 a shell configured to receive vapor heat transfer fluid;   a condensing section comprising a first tube bundle and a second tube bundle extending within the shell, wherein the first tube bundle and the second tube bundle are configured to place the vapor heat transfer fluid in a heat exchange relationship with cooling fluid to produce liquid heat transfer fluid from the vapor heat transfer fluid;   a pre-subcooler disposed between the first tube bundle and the second tube bundle, wherein the pre-subcooler comprises a trough configured to collect a portion of the liquid heat transfer fluid produced by the first tube bundle; and   a subcooling section comprising a plurality of heat exchange tubes extending within the shell, wherein the pre-subcooler is configured to direct the portion of the liquid heat transfer fluid to the subcooling section, and wherein the plurality of heat exchange tubes is configured to place the portion of the liquid heat transfer fluid in a heat exchange relationship with cooling fluid directed through the plurality of heat exchange tubes to subcool the portion of the liquid heat transfer fluid.   
     
     
         17 . The condenser of  claim 16 , wherein the pre-subcooler is configured to direct the portion of the liquid heat transfer fluid onto longitudinal ends of second tube bundle and to block flow of the portion of the liquid heat transfer fluid from the first tube bundle onto a central portion of the second tube bundle. 
     
     
         18 . The condenser of  claim 16 , wherein the pre-subcooler comprises a basin and pre-subcooler heat exchange tubes extending within the basin, wherein the condenser is configured to direct cooling fluid through the pre-subcooler heat exchange tubes to pre-subcool the portion of the liquid heat transfer fluid. 
     
     
         19 . The condenser of  claim 16 , wherein the pre-subcooler comprises a trough configured to collect the portion of the liquid heat transfer fluid, wherein the trough comprises a sheet and lateral segments extending cross-wise from the sheet to form a basin of the trough, wherein the sheet is a solid piece of material that does not include apertures formed therein. 
     
     
         20 . The condenser of  claim 16 , wherein the pre-subcooler comprises a first trough configured to collect the portion of the liquid heat transfer fluid, wherein the pre-subcooler comprises a second trough configured to collect an additional portion of the liquid heat transfer fluid and to direct the additional portion of the liquid heat transfer fluid to the subcooling section, and the first trough and the second trough are aligned with one another along a lateral axis of the condenser.