Refrigerant Dehumidification System with Variable Condenser Unloading

Abstract

A condenser in a refrigerant system is provided with a plurality of refrigerant circuits, with at least one of the plurality of circuits being equipped with a shut off device. A reheat coil is also incorporated into the refrigerant system to provide enhanced dehumidification functionality. By selectively shutting off at least one of the active refrigerant circuits in the condenser, the amount of heat rejected by the condenser as well as by the reheat coil can be controlled shifting the heat load between the condenser and reheat coil. In this manner, and in combination with operation of the reheat cycle, incremental dehumidification and cooling/heating can be provided and humidity and temperature can be precisely controlled.

1 . A refrigerant system comprising:
 a compressor, said compressor delivering a refrigerant to a downstream condenser through a discharge line, said discharge line communicating with a plurality of parallel flow paths passing through said condenser, and at least one of said plurality of flow paths having a shut-off device;   a line communicating downstream of said condenser to an expansion device, and downstream of said expansion device to an evaporator, and a line communicating from said evaporator back to said compressor; and   a reheat circuit incorporated into said refrigerant system, said reheat circuit receiving a refrigerant, and passing said received refrigerant through a reheat heat exchanger, and from said reheat heat exchanger back into a main refrigerant circuit, an air-moving device for moving air over said evaporator, and over said reheat heat exchanger, and a control for selectively opening said shutoff device to achieve desired control in combination with said reheat circuit.   
   
   
       2 . The refrigerant system as set forth in  claim 1 , wherein a bypass line allows selective bypass of at least a portion of refrigerant around said condenser, and said bypass line also includes a bypass valve, with said control selectively controlling said bypass valve. 
   
   
       3 . The refrigerant system as set forth in  claim 1 , wherein said reheat circuit taps refrigerant from a location downstream of said condenser. 
   
   
       4 . The refrigerant system as set forth in  claim 1 , wherein said reheat circuit taps refrigerant from a location upstream of said condenser. 
   
   
       5 . The refrigerant system as set forth in  claim 4 , wherein said discharge line from said compressor branches into said plurality of parallel flow paths, and said reheat circuit taps refrigerant from a location upstream of a branching point. 
   
   
       6 . The refrigerant system as set forth in  claim 1 , wherein there are at least three of said flow paths, and at least two of said at least three flow paths having shut-off devices. 
   
   
       7 . The refrigerant system as sot forth in  claim 1 , wherein said control operating said shut-off device to block flow of refrigerant through said at least one of said plurality of flow paths when less cooling is desired. 
   
   
       8 . The refrigerant system as set forth in  claim 7 , wherein said control operates said shut-off device to block the flow of refrigerant through said at least one of said plurality of flow paths to achieve a desired amount of dehumidification, with lesser cooling, when less cooling is desired. 
   
   
       9 . The refrigerant system as set forth in  claim 1 , wherein said control shuts said shut-off device to block flow of refrigerant through at least one of said plurality of flow paths, while still allowing flow through at least one other of said plurality of flow paths to reduce the cooling load provided by refrigerant passing through the condenser. 
   
   
       10 . A method of controlling a refrigerant system comprising:
 providing a compressor, said compressor delivering a compressed refrigerant to a downstream condenser through a discharge line, said discharge line communicating with a plurality of parallel flow paths passing through said condenser, and at least one of said plurality of flow paths having a shut off device;   communicating refrigerant downstream of said condenser to an expansion device, and downstream or said expansion device to an evaporator, and communicating refrigerant from said evaporator back to said compressor; and   a reheat circuit incorporated into said refrigerant system, said reheat circuit receiving a refrigerant, and passing said received refrigerant through a reheat heat exchanger, and from said reheat heat exchanger back into a main refrigerant circuit, an air-moving device moving air over said evaporator, and over said reheat heat exchanger, and a control selectively opening said shutoff device to achieve desired control in combination with said reheat circuit.   
   
   
       11 . The method as set forth in  claim 10  wherein a bypass line allows selective bypass of at least a portion of refrigerant around said condenser, and said bypass line also includes a bypass valve, with said control selectively controlling said bypass valve. 
   
   
       12 . The method as set forth in  claim 10 , wherein said reheat circuit taps refrigerant from a location downstream of said condenser. 
   
   
       13 . The method as set forth in  claim 10 , wherein said reheat circuit taps refrigerant from a location upstream of said condenser. 
   
   
       14 . The method as set forth in  claim 13 , wherein said discharge line from said compressor branches into said plurality of parallel flow paths, and said reheat circuit taps refrigerant from a location upstream of a branching point. 
   
   
       15 . The method as set forth in  claim 10 , wherein there are at least three of said flow paths, and at least two of said at least three flow paths having shut off devices. 
   
   
       16 . The method as set forth in  claim 10 , wherein said control operating said shut-off valve device to block flow of refrigerant through said at least one of said plurality of flow paths when less cooling is desired. 
   
   
       17 . The method as set forth in  claim 10 , wherein said control operating said shut-off device to block flow of refrigerant through said at least one of said plurality of flow paths when less cooling is desired. 
   
   
       18 . The method as set forth in  claim 10 , wherein said control operates said shut-off device to block the flow of refrigerant through said at least one of said plurality of flow paths to achieve a desired amount of dehumidification, with lesser cooling, when less cooling is desired. 
   
   
       19 . The method as set forth in  claim 10 , wherein said control shuts said shut-off device to block flow of refrigerant through at least one of said plurality of flow paths, while still allowing flow through at least one other of said plurality of flow paths to reduce the cooling load provided by refrigerant passing through the condenser.