Capillary tube for a packaged terminal air conditioner unit

Abstract

A capillary tube for a heat pump system, such as a packaged terminal air conditioner unit, includes features for adjusting a restriction on a flow of refrigerant through the capillary tube depending upon a direction of the flow of refrigerant through the capillary tube. A related packaged terminal air conditioner unit is also provided.

What is claimed is: 
     
         1 . A packaged terminal air conditioner unit, comprising:
 a casing extending between an exterior side portion and an interior side portion;   a compressor positioned within the casing, the compressor operable to compress a refrigerant;   an interior coil positioned within the casing at the interior side portion of the casing;   an exterior coil positioned within the casing at the exterior side portion of the casing;   a reversing valve in fluid communication with the compressor in order to receive compressed refrigerant from the compressor, the reversing valve configured for selectively directing the compressed refrigerant from the compressor to either the interior coil or the exterior coil;   a capillary tube extending between the interior coil and the exterior coil in order to direct refrigerant between the interior coil and the exterior coil, the capillary tube comprising means for adjusting a restriction on a flow of refrigerant through the capillary tube depending upon a direction of the flow of refrigerant through the capillary tube.   
     
     
         2 . The packaged terminal air conditioner unit of  claim 1 , wherein the capillary tube extends between a first end portion and a second end portion, the first end portion of the capillary tube positioned adjacent the exterior coil, the second end portion of the capillary tube positioned adjacent the interior coil, the capillary tube defining an interior volume for directing the flow of refrigerant through the capillary tube, the means for adjusting the restriction comprising a wire positioned within the interior volume of the capillary tube at the first end portion of the capillary tube. 
     
     
         3 . The packaged terminal air conditioner unit of  claim 2 , wherein the wire is mounted to the capillary tube at the first end portion of the capillary tube. 
     
     
         4 . The packaged terminal air conditioner unit of  claim 2 , wherein the capillary tube and the wire are bent at the first end portion of the capillary tube in order to hinder movement of the wire within the interior volume of the capillary tube. 
     
     
         5 . The packaged terminal air conditioner unit of  claim 2 , wherein the capillary tube and the wire are constructed of copper. 
     
     
         6 . The packaged terminal air conditioner unit of  claim 1 , wherein the capillary tube extends between a first end portion and a second end portion, the first end portion of the capillary tube positioned adjacent the exterior coil, the second end portion of the capillary tube positioned adjacent the interior coil, the means for adjusting the restriction comprising a crimp defined by the capillary tube at the first end portion of the capillary tube. 
     
     
         7 . The packaged terminal air conditioner unit of  claim 1 , wherein the capillary tube extends between a first end portion and a second end portion, the first end portion of the capillary tube positioned adjacent the exterior coil, the second end portion of the capillary tube positioned adjacent the interior coil, the means for adjusting the restriction comprising a fixed restriction orifice positioned at the first end portion of the capillary tube. 
     
     
         8 . The packaged terminal air conditioner unit of  claim 7 , wherein the fixed restriction orifice is brazed or interference fit onto the capillary tube at the first end portion of the capillary tube. 
     
     
         9 . The packaged terminal air conditioner unit of  claim 7 , wherein the fixed restriction orifice is brazed or interference fit onto a jumper tube of the exterior coil. 
     
     
         10 . The packaged terminal air conditioner unit of  claim 1 , wherein the capillary tube extends between a first end portion and a second end portion, the first end portion of the capillary tube positioned adjacent the exterior coil, the second end portion of the capillary tube positioned adjacent the interior coil, the means for adjusting the restriction comprising a plurality of coils defined by the capillary tube at the first end portion of the capillary tube. 
     
     
         11 . The packaged terminal air conditioner unit of  claim 1 , wherein the capillary tube extends between a first end portion and a second end portion, the first end portion of the capillary tube positioned adjacent the exterior coil, the second end portion of the capillary tube positioned adjacent the interior coil, the capillary tube defining an interior volume for directing the flow of refrigerant through the capillary tube, the means for adjusting the restriction comprising a flow washer positioned within the interior volume of the capillary tube at the first end portion of the capillary tube. 
     
     
         12 . The packaged terminal air conditioner unit of  claim 1 , wherein the capillary tube extends between a first end portion and a second end portion, the first end portion of the capillary tube positioned adjacent the exterior coil, the second end portion of the capillary tube positioned adjacent the interior coil, the capillary tube defining an interior volume for directing the flow of refrigerant through the capillary tube, the means for adjusting the restriction comprising a plurality of conical segments defined by an inner surface of the capillary tube proximate at the first end portion of the capillary tube. 
     
     
         13 . The packaged terminal air conditioner unit of  claim 12 , wherein each conical segment of the plurality of conical segments expands along an axial direction defined between the first and second end portions of the capillary tube. 
     
     
         14 . The packaged terminal air conditioner unit of  claim 1 , wherein the capillary tube extends between a first end portion and a second end portion, the first end portion of the capillary tube positioned adjacent the exterior coil, the second end portion of the capillary tube positioned adjacent the interior coil, the capillary tube defining an interior volume for directing the flow of refrigerant through the capillary tube, the means for adjusting the restriction comprising a piston disposed within the interior volume of the capillary tube at the first end portion of the capillary tube, the piston slidable within the interior volume between a first position and a second position, the piston obstructing more refrigerant flow through the interior volume of the capillary tube in the first position than in the second position. 
     
     
         15 . A packaged terminal air conditioner unit, comprising:
 a casing;   a compressor positioned within the casing, the compressor operable to increase a pressure of a refrigerant;   a reversing valve positioned within the casing, the reversing valve in fluid communication with the compressor in order to receive compressed refrigerant from the compressor;   an interior coil positioned within the casing;   an exterior coil positioned within the casing opposite the interior coil, the interior coil and the exterior coil in fluid communication with the reversing valve such that either the interior coil or the exterior coil receive the compressed refrigerant from the reversing valve; and   a capillary tube extending between the interior coil and the exterior coil in order to direct refrigerant between the interior coil and the exterior coil, the capillary tube extending between a first end portion and a second end portion, the first end portion of the capillary tube positioned adjacent the exterior coil, the second end portion of the capillary tube positioned adjacent the interior coil, the capillary tube defining an interior volume for directing the flow of refrigerant through the capillary tube; and   a block positioned within the interior volume of the capillary tube at the first end portion of the capillary tube such that the block occupies a portion of the interior volume of the tubular body at the first end portion of the tubular body.   
     
     
         16 . The packaged terminal air conditioner unit of  claim 15 , wherein the block is mounted to the capillary tube at the first end portion of the capillary tube. 
     
     
         17 . The packaged terminal air conditioner unit of  claim 15 , wherein the capillary tube and the block are bent at the first end portion of the capillary tube in order to hinder movement of the block within the interior volume of the capillary tube. 
     
     
         18 . The packaged terminal air conditioner unit of  claim 15 , wherein the capillary tube and the block are constructed of copper. 
     
     
         19 . The packaged terminal air conditioner unit of  claim 15 , wherein the capillary tube is constructed of a first material and the block is constructed of a second material, the first and second material being different. 
     
     
         20 . A capillary tube for a heat pump system, comprising:
 a tubular body extending between a first end portion and a second end portion, the tubular body defining an interior volume for directing a flow of refrigerant through the tubular body, cross-sections of the interior volume of the tubular body being substantially constant between the first and second end portions of the tubular body;   a block positioned within the interior volume of the tubular body at the first end portion of the tubular body such that the block occupies a portion of the interior volume of the tubular body at the first end portion of the tubular body.