Heat exchanger refrigerant drain

Abstract

A combination refrigeration displacement and drain device is disclosed that can be mounted within a heat exchanger, such as a shell and tube heat exchanger, which may be used for example as a heat exchanger in a chiller unit, which may be used in an HVAC or refrigeration system. One example of such components can include heat exchangers, such as for example a condenser employing a gravity drain. Advantageously, the combination refrigeration displacement and drain device herein can provide a refrigerant charge reduction for example that is used in the chiller unit, while facilitating drainage out of the heat exchanger. The combination refrigeration displacement and drain device can alleviate the liquid refrigerant accumulation that may normally be necessary to induce flow in a gravity drain design.

What is claimed is: 
     
         1 . A shell-and-tube heat exchanger, comprising:
 a shell having a volume, a refrigerant inlet, and a refrigerant outlet, the refrigerant inlet being disposed at a relatively higher vertical elevation of the shell than the refrigerant outlet such that gravitational force induces flow of refrigerant from the refrigerant inlet toward the refrigerant outlet;   heat exchanger tubes extending longitudinally in the shell; and   a combination refrigerant displacement and drain device disposed within the shell and separating the volume inside the shell, the combination refrigerant displacement and drain device comprising:
 a plurality of slanted portions which slant from a first vertical elevation in the shell toward a second vertical elevation in the shell, the second vertical elevation being relatively closer to a bottom of the shell, the plurality of slanted portions extending from an end of the shell toward the refrigerant outlet, wherein the plurality of slanted portions converge to form a channel, the channel adapted to guide the refrigerant toward the refrigerant outlet. 
   
     
     
         2 . The shell-and-tube heat exchanger according to  claim 1 , wherein the heat exchanger tubes are disposed at a vertical elevation that is relatively closer to the refrigerant inlet than the combination refrigerant displacement and drain device. 
     
     
         3 . The shell-and-tube heat exchanger according to  claim 1 , wherein the plurality of slanted portions extend continuously from the end of the shell toward the refrigerant outlet. 
     
     
         4 . The shell-and-tube heat exchanger according to  claim 1 , further comprising a sump area disposed in fluid communication with the channel and the refrigerant outlet, the sump being disposed between the channel and the refrigerant outlet. 
     
     
         5 . The shell-and-tube heat exchanger according to  claim 1 , wherein the plurality of slanted portions converge to form a plurality of channels. 
     
     
         6 . The shell-and-tube heat exchanger according to  claim 1 , wherein a first end of the plurality of slanted portions at the first vertical elevation is disposed at an end of the shell that is opposite the refrigerant outlet, and a second end of the plurality of slanted portions at the second vertical elevation is disposed relatively closer to the refrigerant outlet. 
     
     
         7 . The shell-and-tube heat exchanger according to  claim 1 , wherein the plurality of slanted portions are designed based on a relative velocity profile of the refrigerant in the shell. 
     
     
         8 . The shell-and-tube heat exchanger according to  claim 1 , wherein the heat exchanger is a condenser heat exchanger. 
     
     
         9 . A chiller for a heating, ventilation, and air conditioning (HVAC) system, comprising:
 a shell-and-tube heat exchanger, comprising:
 a shell having a volume, a refrigerant inlet, and a refrigerant outlet, the refrigerant inlet being disposed at a relatively higher vertical elevation of the shell than the refrigerant outlet such that gravitational force induces flow of refrigerant from the refrigerant inlet toward the refrigerant outlet; 
 heat exchanger tubes extending longitudinally in the shell; and 
 a combination refrigerant displacement and drain device disposed within the shell and separating the volume inside the shell, the combination refrigerant displacement and drain device comprising:
 a plurality of slanted portions which slant from a first vertical elevation in the shell toward a second vertical elevation in the shell, the second vertical elevation being relatively closer to a bottom of the shell, the plurality of slanted portions extending from an end of the shell toward the refrigerant outlet, wherein the plurality of slanted portions converge to form a channel, the channel adapted to guide the refrigerant toward the refrigerant outlet. 
 
   
     
     
         10 . The chiller according to  claim 9 , wherein the shell-and-tube heat exchanger is a condenser heat exchanger. 
     
     
         11 . The chiller according to  claim 9 , wherein the heat exchanger tubes carry a process fluid. 
     
     
         12 . The chiller according to  claim 11 , wherein the process fluid is water. 
     
     
         13 . The chiller according to  claim 9 , wherein the combination refrigerant displacement and drain device is adapted to prevent refrigerant from collecting at the bottom of the shell. 
     
     
         14 . The chiller according to  claim 9 , wherein the plurality of slanted portions extend continuously along a length of the shell. 
     
     
         15 . The chiller according to  claim 14 , wherein the plurality of slanted portions is designed based on a relative velocity profile of the refrigerant in the shell. 
     
     
         16 . The chiller according to  claim 9 , wherein the plurality of slanted portions converge to form a plurality of channels. 
     
     
         17 . The chiller according to  claim 9 , wherein the heat exchanger tubes are disposed at a vertical elevation that is relatively closer to the refrigerant inlet than the combination refrigerant displacement and drain device. 
     
     
         18 . The chiller according to  claim 9 , wherein the plurality of slanted portions extend continuously from the end of the shell toward the refrigerant outlet. 
     
     
         19 . The chiller according to  claim 9 , further comprising a sump area disposed in fluid communication with the channel and the refrigerant outlet, the sump being disposed between the channel and the refrigerant outlet. 
     
     
         20 . The chiller according to  claim 9 , wherein a first end of the plurality of slanted portions at the first vertical elevation is disposed at an end of the shell that is opposite the refrigerant outlet, and a second end of the plurality of slanted portions at the second vertical elevation is disposed relatively closer to the refrigerant outlet.