Cascade refrigerant line set

Abstract

A refrigeration line set is provided including a gas line with first and second openings formed through a sidewall thereof. A liquid line includes exterior sections and an interior section extending through the gas line. A connection unit is positioned at each opening in the gas line, and each connection unit includes a line fitting attached to an end of the interior section of the liquid line, and a cap attached to an end of an exterior section of the liquid line and fixed to the sidewall of the gas line around the opening.

What is claimed is: 
     
         1 . A refrigeration circuit comprising:
 a condenser;   an evaporator; and   a line set extending from the condenser to the evaporator and comprising:
 a gas line comprising: a first end connected to the condenser, and a second end connected to the evaporator; 
 a liquid line comprising a first end connected to the condenser a second end connected to the evaporator, and an interior section, disposed between the first end and the second end and running through an interior of the gas line. 
   
     
     
         2 . The refrigeration circuit according to  claim 1 ,
 wherein the liquid line enters the interior of the gas line via a first opening in the gas line and exits from the interior of the gas line via a second opening in the gas line, and   wherein the line set further comprises a first connection unit sealing the first opening in the gas line around the liquid line and a second connection unit sealing the second opening in the gas line around the liquid line.   
     
     
         3 . A refrigeration circuit leak detection system comprising:
 the refrigeration circuit according to  claim 1 , wherein the liquid line extends from the condenser, through a first opening in a sidewall of the gas line, through the interior of the gas line, through a second opening in the sidewall of the gas line, and to the evaporator;   a first temperature sensor configured to detect a first temperature of gas in the gas line adjacent to the first opening;   a second temperature sensor configured to detect a second temperature of gas in the gas line adjacent to the second opening; and   a controller comprising: a non-volatile memory storing instructions thereon, and at least one hardware processor coupled to the memory and configured to execute the instructions and thereby:
 receive a first detected temperature from the first temperature sensor; 
 receive a second detected temperature from the second temperature sensor; 
 determining a temperature change between the first detected temperature and the second detected temperature; 
 comparing the temperature change to a threshold; and 
 outputting an alert based on the temperature change being greater than the threshold. 
   
     
     
         4 . A connection unit of a refrigeration line set, the connection unit comprising:
 a cap comprising:
 a tube element configured to be attached around an end of a first liquid line section, and 
 a flange element extending radially outward from the tube element; 
   a line fitting comprising:
 a first fitting element configured to be attached to the tube element, 
 a second fitting element configured to be attached around an end of a second liquid line section, and 
 a connecting element disposed between the first fitting element and the second fitting element and providing a sealed connection between the first fitting element and the second fitting element. 
   
     
     
         5 . The connection unit according to  claim 4 , wherein the connecting element is rotatably connected to the first fitting element and to the second fitting element. 
     
     
         6 . The connection unit according to  claim 4 , wherein the connecting element is removably connectable to the first fitting element and to the second fitting element. 
     
     
         7 . The connection unit according to  claim 4 , further comprising:
 a flange clamp configured to clamp the flange element of the cap to a flange attached around an opening in a gas line.   
     
     
         8 . A refrigeration line set comprising:
 a gas line comprising an opening formed through a sidewall thereof;   a liquid line comprising: exterior first liquid line section, and interior second liquid line section disposed within the gas line; and   the connection unit according to  claim 4 , wherein:
 the tube element is attached around the end of the first liquid line section, 
 the flange element is sealed to the sidewall of the gas line around the opening, and 
 the second fitting element is attached around the end of the second liquid line section. 
   
     
     
         9 . The refrigeration line set according to  claim 8 , wherein the connection unit further comprises:
 a gas line flange fixed to the sidewall of the gas line around the opening, and   a flange clamp attaching the flange element to the gas line flange.   
     
     
         10 . The refrigeration circuit according to  claim 8 , further comprising:
 a temperature sensor disposed to sense a temperature within the gas line adjacent to the connection unit.   
     
     
         11 . A method of assembling a refrigeration line set, the method comprising:
 sealing a cap to an end of an exterior section of a liquid line;   sealing a line fitting to an end of an interior section of the liquid line;   extending the interior section of the liquid line into a gas line via an opening in a sidewall of the gas line;   sealing the cap to the line fitting, thereby connecting the exterior section of the liquid line to the interior section of the liquid line; and   sealing the cap to the sidewall of the gas line around the opening therein.