Dynamic cycle air conditioner with incremental dehumidification incorporating multiple circuits of the volume of air

Abstract

Incremental dehumidification of a volume of air in an indirect evaporative cooler. Dehumidification processes are incorporated with the cooling processes, such that within each circuit a volume of air follows through the indirect evaporative cooler and includes dehumidification as well as cooling of the volume of air. Subsequent circuits of the volume of air, which commence at a lower starting temperature than the prior circuit, result in further dehumidification of the air.

What is claimed is: 
     
         1 . An indirect evaporative cooler apparatus comprising:
 a heat exchanger comprising a dry passage and a wet passage, the dry passage in thermodynamic communication with the wet passage and separated from the wet passage by a substantially liquid-impermeable membrane having a hydrophobic surface facing the dry passage and a hydrophilic surface facing the wet passage, the dry passage comprising an intake portion, an outlet portion, and a loop portion;   a mixing valve disposed in the dry passage and configured to selectively pass intake air from the intake portion, recirculation air from the loop portion, or a combination thereof;   a first fan disposed downstream of the mixing valve and adapted to move a first volume of air into and through the loop portion;   a diverting valve disposed in the dry passage and configured to selectively pass outlet air to the outlet portion, recirculation air to the mixing valve, or a combination thereof; and   a controller adapted to operate the mixing valve, the first fan, the diverting valve, and a combination thereof, for cooling the first volume substantially to its dew point, and for incrementally further cooling and dehumidifying the first volume of air.   
     
     
         2 . The apparatus of  claim 1 , further comprising a water source having a pressure valve associated therewith, and a nozzle configured to wet the wet passage for evaporative cooling of the substantially liquid-impermeable membrane. 
     
     
         3 . The apparatus of  claim 2 , wherein the water enclosure is pressurized by the pressure valve to a threshold level such that positive pressure is maintained sufficient for the nozzle to dispense water. 
     
     
         4 . The apparatus of  claim 1 , further comprising a second fan and an enclosure valve associated therewith configured to develop a negative pressure relative to ambient pressure within the wet passage. 
     
     
         5 . The apparatus of  claim 1 , wherein the dry passage is arranged in a descending serpentine configuration, and further wherein the intake portion is disposed at a top portion of the descending serpentine configuration, and the outlet is disposed at a bottom portion of the descending serpentine configuration. 
     
     
         6 . The apparatus of  claim 5 , wherein the dry passage has a hexagonal cross-section. 
     
     
         7 . The apparatus of  claim 6  further comprising air traps disposed within the dry passage. 
     
     
         8 . The apparatus of  claim 6  further comprising a heat exchange coil disposed within the dry passage. 
     
     
         9 . The apparatus of  claim 1 , further comprising a dry passage water nozzle configured to expel accumulated water from dehumidification of the first volume of air. 
     
     
         10 . The apparatus of  claim 9 , wherein the dry passage is maintained at a positive pressure relative to ambient pressure. 
     
     
         11 . A method of incrementally dehumidifying air in an indirect evaporative cooler, the method comprising:
 having a heat exchanger comprising a dry passage and a wet passage, the dry passage in thermodynamic communication with the wet passage and separated from the wet passage by a substantially liquid-impermeable membrane having a hydrophobic surface facing the dry passage and a hydrophilic surface facing the wet passage, the dry passage comprising an intake portion, an outlet portion, and a loop portion;   selectively passing intake air from the intake portion, recirculation air from the loop portion, or a combination thereof by a mixing valve disposed in the dry passage;   moving air into and through the loop portion by a first fan disposed downstream of the mixing valve;   selectively passing outlet air to the outlet portion, recirculation air to the mixing valve, or a combination thereof by a controller adapted to operate a diverting valve disposed in the dry passage; and   cooling the first volume of air substantially to its dew point, and incrementally further cooling and dehumidifying the first volume of air by the controller operating the mixing valve, the first fan, the diverting valve, and a combination thereof.   
     
     
         12 . The method of  claim 11  further comprising wetting the wet passage by a water source having an associated pressure valve and a nozzle, for evaporative cooling of the substantially liquid-impermeable membrane. 
     
     
         13 . The method of  claim 12 , further comprising pressurizing the water enclosure by the pressure valve to a threshold level such that positive pressure is maintained sufficient for the nozzle to dispense water. 
     
     
         14 . The method of  claim 11 , further comprising developing a negative pressure relative to ambient pressure within the wet passage, by a second fan and an enclosure valve associated therewith. 
     
     
         15 . The method of  claim 11 , wherein the dry passage is arranged in a descending serpentine configuration, and further wherein the intake portion is disposed at a top portion of the descending serpentine configuration, and the outlet is disposed at a bottom portion of the descending serpentine configuration. 
     
     
         16 . The method of  claim 15 , wherein the dry passage has a hexagonal cross-section. 
     
     
         17 . The method of  claim 16  further comprising air traps disposed within the dry passage. 
     
     
         18 . The method of  claim 16  further comprising a heat exchange coil disposed within the dry passage. 
     
     
         19 . The method of  claim 11 , further comprising expelling accumulated water from dehumidification of the first volume of air by a dry passage water nozzle. 
     
     
         20 . The method of  claim 19 , further comprising maintaining the dry passage at a positive pressure relative to ambient pressure. 
     
     
         21 . A system for incrementally dehumidifying air, the system comprising:
 an evaporative liquid reservoir comprising a pressure valve and a channel adapted to transport evaporative liquid;   a heat exchanger comprising:
 a dry passage and a wet passage, the dry passage in thermodynamic communication with the wet passage and separated from the wet passage by a substantially liquid-impermeable membrane having a hydrophobic surface facing the dry passage and a hydrophilic surface facing the wet passage, the dry passage comprising an intake portion, an outlet portion, and a loop portion; 
 a nozzle coupled with the channel and configured to wet the wet passage for evaporative cooling of the substantially liquid-impermeable membrane; 
 a mixing valve disposed in the dry passage and configured to selectively pass intake air from the intake portion, recirculation air from the loop portion, or a combination thereof; and 
 a diverting valve disposed in the dry passage and configured to selectively pass outlet air to the outlet portion, recirculation air to the mixing valve, or a combination thereof; and 
 a controller adapted to operate the pressure valve, the mixing valve, the diverting valve, and a combination thereof, for cooling a first volume of air substantially to its dew point, and for incrementally further cooling and dehumidifying the first volume of air. 
   
     
     
         22 . The system of  claim 21 , wherein the evaporative liquid reservoir is pressurized by the pressure valve to a threshold level such that positive pressure is maintained sufficient for the nozzle to dispense evaporative liquid onto the wet liquid-impermeable membrane. 
     
     
         23 . The system of  claim 21 , wherein the heat exchanger further comprises a fan and an enclosure valve associated therewith configured to develop a negative pressure relative to ambient pressure within the wet passage. 
     
     
         24 . The system of  claim 21 , wherein the dry passage is arranged in a descending serpentine configuration, and further wherein the intake portion is disposed at a top portion of the descending serpentine configuration, and the outlet is disposed at a bottom portion of the descending serpentine configuration. 
     
     
         25 . The system of  claim 24 , wherein the dry passage has a hexagonal cross-section. 
     
     
         26 . The system of  claim 24  further comprising air traps disposed within the dry passage. 
     
     
         27 . The system of  claim 24  further comprising a heat exchange coil disposed within the dry passage. 
     
     
         28 . The system of  claim 21 , further comprising a dry passage water nozzle disposed in the dry passage and configured to expel accumulated water from dehumidification of the first volume of air. 
     
     
         29 . The system of  claim 28 , wherein the dry passage is maintained at a positive pressure relative to ambient pressure.