Parallel evaporator coils for superheat control for a dehumidification system

Abstract

A dehumidification system includes a primary metering device, a secondary metering device, an intermixed coil unit, a primary evaporator, a secondary condenser, a first modulating valve, and a compressor.

What is claimed is: 
     
         1 . A dehumidification system comprising:
 a primary metering device;   a secondary metering device;   an intermixed coil unit operable to:
 receive an inlet airflow and output a first airflow, the first airflow comprising cooler air than the first inlet airflow, the first airflow generated by transferring heat from the inlet airflow to a flow of refrigerant within a superheat control evaporator and a secondary evaporator as the inlet airflow passes through both the superheat control evaporator and the secondary evaporator, 
 wherein the intermixed coil unit comprises:
 the superheat control evaporator operable to receive a flow of refrigerant from a primary evaporator; and 
 the secondary evaporator operable to receive the flow of refrigerant from the primary metering device; 
 
   a primary evaporator operable to:
 receive the flow of refrigerant from a first modulating valve and/or a secondary condenser; and 
 receive the first airflow and output a second airflow, the second airflow comprising cooler air than the first airflow, the second airflow generated by transferring heat from the first airflow to the flow of refrigerant as the first airflow pass through the primary evaporator; 
   the secondary condenser operable to:
 receive the flow of refrigerant from the first modulating valve; and 
 receive the second airflow and output a third airflow; 
   the first modulating valve operable to:
 receive the flow of refrigerant from the secondary evaporator; 
 direct the flow of refrigerant to the secondary condenser during a first mode of operation; 
 direct the flow of refrigerant to the primary evaporator during a second mode of operation, wherein the flow of refrigerant bypasses the secondary condenser; and 
 direct a portion of the flow of refrigerant to the secondary condenser and a remaining portion of the flow of refrigerant to the primary evaporator during a third mode of operation; 
   a compressor configured to:
 receive the flow of refrigerant from the superheat control evaporator and discharge the flow of refrigerant at a higher pressure than the flow of refrigerant received at the compressor; and 
   a primary condenser operable to:
 receive the flow of refrigerant discharged from the compressor; 
 in response to receiving the flow of refrigerant from the compressor, output a dischargeable airflow. 
   
     
     
         2 . The dehumidification system of  claim 1 , further comprising a sub-cooling coil operable to:
 receive the flow of refrigerant from the primary condenser;   output the flow of refrigerant to the primary metering device; and   receive the third airflow and output a fourth airflow, the fourth airflow generated by transferring heat from the flow of refrigerant to the third airflow as the third airflow passes through the sub-cooling coil.   
     
     
         3 . The dehumidification system of  claim 2 , wherein the sub-cooling coil and primary condenser are combined in a single coil unit. 
     
     
         4 . The dehumidification system of  claim 2 , wherein the primary condenser is further operable to:
 receive the fourth airflow and generate the dischargeable airflow based on the received fourth airflow, the dischargeable airflow generated by transferring heat from the flow of refrigerant to the fourth airflow as the fourth airflow contacts the primary condenser.   
     
     
         5 . The dehumidification system of  claim 1 , wherein the primary condenser is further operable to:
 receive the third airflow and generate the dischargeable airflow based on the received third airflow, the dischargeable airflow generated by transferring heat from the flow of refrigerant to the third airflow as the third airflow contacts the primary condenser.   
     
     
         6 . The dehumidification system of  claim 1 , wherein during the first mode of operation:
 the third airflow comprises warmer and less humid air than the second airflow, the third airflow generated by transferring heat from the flow of refrigerant to the second airflow as the second airflow passes through the secondary condenser.   
     
     
         7 . The dehumidification system of  claim 1 , wherein during the second mode of operation, the third airflow comprises approximately the same temperature and humidity as the second airflow. 
     
     
         8 . The dehumidification system of  claim 1 , further comprising an alternate condenser disposed in an external condenser unit, operable to:
 receive the flow of refrigerant discharged from the compressor;   in response to receiving the flow of refrigerant from the compressor, output a second dischargeable airflow, the second dischargeable airflow generated by transferring heat heat away from the flow of refrigerant received by the compressor.   
     
     
         9 . The dehumidification system of  claim 1 , wherein two or more members selected from the group consisting of the secondary evaporator, the primary evaporator, and the secondary condenser are combined in a single coil pack. 
     
     
         10 . The dehumidification system of  claim 1 , wherein at least one of the primary evaporator and the secondary evaporator comprises two or more circuits for the flow of refrigerant.