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.

1 - 20 . (canceled) 
     
     
         21 . A heating, ventilation, and air conditioning (HVAC) system, comprising:
 a compressor, a condenser, an expander, and an evaporator,   the compressor, the condenser, the expander, and the evaporator are fluidly connected,   the condenser is configured to condense vapor refrigerant received from the compressor to liquid refrigerant,   the condenser comprising:
 a shell having a volume, a length, a first end, a second end, a refrigerant inlet, and a refrigerant outlet, the shell being cylindrical, 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, the length of the shell extending from the first end to the second end in a longitudinal direction, the refrigerant outlet being disposed in the middle of the shell along the longitudinal direction; 
 heat exchanger tubes extending in the longitudinal direction of the shell between tubesheets; 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 slants 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 cylindrical part of the shell, the plurality of slants extending and slanting toward the refrigerant outlet in the longitudinal direction, wherein the plurality of slants converge to form a channel, the channel extending a length of one of the plurality of slants, and the channel adapted to guide the refrigerant toward the refrigerant outlet, 
 wherein the combination refrigerant displacement and drain device is configured to prevent refrigerant from collecting and accumulating in the volume of the shell which is between the combination refrigerant displacement and drain device and the bottom cylindrical part of the shell, 
 wherein the combination refrigerant displacement and drain device displaces a portion of the volume of the shell, which is between the combination refrigerant displacement and drain device and the bottom cylindrical part of the shell, the portion being a displaced refrigerant volume, 
 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, 
 wherein in operation, the flow of refrigerant is directed into the shell of the condenser via the refrigerant inlet, such that the combination refrigerant displacement and drain device is configured to direct the flow of refrigerant out of the shell to the expander via the refrigerant outlet, the flow of refrigerant is then directed from the expander to the evaporator, the flow of refrigerant is then directed from the evaporator to the compressor, and the flow of refrigerant is then directed from the compressor back into the shell of the condenser via the refrigerant inlet. 
   
     
     
         22 . The HVAC system according to  claim 21 , wherein the plurality of slants extend continuously along a length of the shell. 
     
     
         23 . The HVAC system according to  claim 22 , wherein the plurality of slants is designed based on a relative velocity profile of the refrigerant in the shell. 
     
     
         24 . The HVAC system according to  claim 21 , wherein the plurality of slants converge to form a plurality of channels. 
     
     
         25 . The HVAC system according to  claim 21 , wherein the plurality of slants extend continuously from an end of the shell toward the refrigerant outlet. 
     
     
         26 . The HVAC system according to  claim 21 , further comprising a sump area disposed in fluid communication with the channel and the refrigerant outlet, the sump area being disposed between the channel and the refrigerant outlet. 
     
     
         27 . The HVAC system according to  claim 21 , wherein a first end of the plurality of slants 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 slants at the second vertical elevation is disposed relatively closer to the refrigerant outlet. 
     
     
         28 . The HVAC system according to  claim 21 , wherein the plurality of slants slant from the first end and the second end of the shell toward the refrigerant outlet in the longitudinal direction.