Method and apparatus for dehumidification

Abstract

An HVAC system including a compressor, a condenser and an evaporator connected in a closed refrigerant loop. The evaporator includes a plurality of refrigerant circuits. The evaporator also includes at least one distributor configured to distribute and deliver refrigerant to each circuit of the plurality of circuits. The plurality of circuits are arranged into a first and second set of circuits. The evaporator also includes a valve configured and disposed to isolate the first set of circuits from refrigerant flow from the condenser and provide flow of refrigerant from the compressor in a dehumidification operation of the HVAC system.

1 . An HVAC system comprising:
 a compressor, a condenser and an evaporator connected in a closed refrigerant loop, the evaporator including a plurality of refrigerant circuits;   the evaporator including at least one distributor configured to distribute and deliver refrigerant to each circuit of the plurality of circuits;   the plurality of circuits being arranged into a first set of circuits and second set of circuits; and   the evaporator including a valve arrangement configured and disposed to isolate the first set of circuits from refrigerant flow from the condenser and to permit flow of refrigerant from the compressor to the first set of circuits in a dehumidification operation of the HVAC system.   
   
   
       2 . The system of  claim 1 , further comprising:
 a first control valve fluidly connected to the first set of circuits, wherein the first control valve controls flow of refrigerant to the first set of circuits; and   a second control valve fluidly connected to the second set of circuits, wherein the second control valve controls flow of refrigerant to the second set of circuits.   
   
   
       3 . The system of  claim 2 , further comprising:
 a first control valve sensor for sensing temperature communicating with the first control valve, the first control valve controlling flow of refrigerant through the first set of circuits in response to the temperature sensed by the first control valve sensor; and   a second control valve sensor for sensing temperature communicating with the second control valve, the second control valve controlling flow of refrigerant through the second set of circuits in response to the temperature sensed by the first control valve sensor.   
   
   
       4 . The system of  claim 3 , wherein the second control valve is capable of permitting a greater amount of refrigerant flow than the first control valve. 
   
   
       5 . The system of  claim 3 , wherein the first and second control valves are thermostatic expansion valves. 
   
   
       6 . The system of  claim 2 , further comprising a header for distributing the flow of refrigerant, the header including a plurality of fluid connections to each of the circuits of the first set of circuits and the second set of circuits, wherein each fluid connection includes a control valve that controls flow of refrigerant through the fluid connection to the corresponding circuit. 
   
   
       7 . The system of  claim 1 , further comprising:
 a fluid connection between the compressor and the first set of circuits allowing flow of at least a portion of refrigerant discharged from the compressor to the first set of circuits,   wherein the flow of refrigerant in the fluid connection bypasses the condenser.   
   
   
       8 . The system of  claim 7 , wherein the fluid connection connects the discharge of the compressor to the inlet of the first set of circuits. 
   
   
       9 . The system of  claim 8 , the fluid connection further comprising a device selected from the group consisting of a bypass valve that can selectively prevent flow of refrigerant through the fluid connection, a flow restriction device that controls the amount of flow through the fluid connection and combinations thereof. 
   
   
       10 . The system of  claim 1 , the valve arrangement further comprising:
 a first valve and second valve in a parallel configuration;   the first valve being configurable into a closed position that prevent flow into or out of the first set of refrigerant circuits and configurable into an open position that allows flow into or out of the first set of refrigerant circuits; and   the second valve being capable of preventing flow of refrigerant into the first set of circuits and allowing flow of refrigerant out of the first set of refrigerant circuits.   
   
   
       11 . The system of  claim 10 , wherein the fluid connection connects the discharge of the compressor to the outlet of the first set of circuits, wherein flow of refrigerant from the compressor through the first set of circuits flows countercurrent to the flow of refrigerant in the second set of circuits in response to a dehumidification operation. 
   
   
       12 . The system of  claim 10 , wherein the fluid connection includes a 3-way valve that selectively connects the outlet of the first set of circuits to either the discharge of the compressor or the inlet of the compressor. 
   
   
       13 . The system of  claim 11 , wherein the refrigerant flowing countercurrent to the flow of refrigerant in the second set of circuits condenses from a gas to a liquid and combines with the inlet of the second set of circuits. 
   
   
       14 . The system of  claim 1 , wherein the first set of circuits includes a plurality of portions, each portion having a predetermined number of circuits and a corresponding valve arrangement arranged and disposed to independently isolate each of the portions from flow of refrigerant from the condenser. 
   
   
       15 . An HVAC system comprising:
 a compressor, a condenser and an evaporator connected in a closed refrigerant loop, the evaporator including a plurality of refrigerant circuits;   the evaporator including at least one distribution arrangement configured to distribute and deliver refrigerant to each circuit of the plurality of circuits;   the plurality of circuits being arranged into a plurality of sets of circuits; and   the evaporator including a valve arrangement configured and disposed to isolate at least one of the sets of circuits from refrigerant flow from the condenser and to permit flow of refrigerant from the compressor to the at least one of the sets of circuits in a dehumidification operation of the HVAC system.   
   
   
       16 . The system of  claim 15 , further comprising:
 a control valve fluidly connected to each of the sets of circuits, wherein the control valve controls flow of refrigerant to the corresponding set of circuits.   
   
   
       17 . The system of  claim 16 , further comprising:
 a control valve sensor for sensing temperature communicating with each of the control valves, each control valve controlling flow of refrigerant through the corresponding set of circuits in response to the temperature sensed by the corresponding control valve sensor.   
   
   
       18 . The system of  claim 15 , further comprising:
 a fluid connection between the compressor and at least one of the sets of circuits allowing flow of at least a portion of refrigerant discharged from the compressor to the corresponding sets of circuits,   wherein the flow of refrigerant in the fluid connection bypasses the condenser.   
   
   
       19 . The system of  claim 18 , wherein the fluid connection connects the discharge of the compressor to the inlet of the corresponding sets of circuits. 
   
   
       20 . The system of  claim 19 , the fluid connection further comprising a device selected from the group consisting of a bypass valve that can selectively prevent flow of refrigerant through the fluid connection, a flow restriction device that controls the amount of flow through the fluid connection and combinations thereof. 
   
   
       21 . The system of  claim 19 , the valve arrangement further comprising:
 a first valve and second valve in a parallel configuration;   the first valve being configurable into a closed position that prevent flow into or out at least one of the plurality of sets of refrigerant circuits and configurable into an open position that allows flow into or out of the corresponding sets of refrigerant circuits; and   the second valve being capable of preventing flow of refrigerant into the first set of circuits and allowing flow of refrigerant out of the corresponding sets of refrigerant circuits.   
   
   
       22 . The system of  claim 21 , wherein the fluid connection connects a discharge of the compressor to the outlet of the corresponding sets of circuits, wherein flow of refrigerant from the compressor through the corresponding sets of circuits flows countercurrent to the flow of refrigerant in the remaining sets of circuits in response to a dehumidification operation. 
   
   
       23 . The system of  claim 21 , wherein the fluid connection includes a 3-way valve that selectively connects the outlet of the corresponding sets of circuits to either a discharge of the compressor or an inlet of the compressor. 
   
   
       24 . The system of  claim 22 , wherein the refrigerant flowing countercurrent to the flow of refrigerant in the second set of circuits condenses from a gas to a liquid and combines with the inlet of the second set of circuits.