Vented Dryer With Modular Heat Pump Subassembly

Abstract

A vented tumble laundry dryer is provided with a heat pump subassembly configured to join with a heater inlet and a blower outlet in an open air flow circuit. The heat pump subassembly forms a closed refrigerant loop. Condenser and evaporator heat exchangers of the subassembly form parts of the open air flow circuit. Air drawn from inside the dryer cabinet passes sequentially through the condenser heat exchanger, the heater, the dryer drum, the process air fan, and the evaporator heat exchanger before being vented to the outside. The heat exchangers have a modular construction that permits one to be stacked on the other and to be angularly offset with respect to the other in both horizontal and vertical planes, thus facilitating integration of the heat pump subassembly into existing vented dryer designs.

1 . A vented laundry dryer comprising:
 a drying chamber;   a process air fan downstream of the drying chamber for drawing air through the drying chamber; and   a heat pump system comprising a condenser heat exchanger unit enclosed by separately formed and mated together first and second casing portions and an evaporator heat exchanger unit enclosed by the second casing portion mated together with a separately formed third casing portion;   wherein the condenser and evaporator heat exchanger units are stacked one on top of the other, said condenser heat exchanger unit connecting to a manifold upstream the drying chamber so that process air is drawn through the condenser heat exchanger unit before entering said drying chamber, and said evaporator heat exchanger unit connecting to an air outlet of said process air fan so that process air is passed through the evaporator heat exchanger unit before being exhausted from the dryer; and   wherein the heat pump system further comprises a coolant circuit comprising a coolant fluid expansion device and a compressor.   
     
     
         2 . The vented laundry dryer of  claim 1  further comprising a heater positioned upstream of the manifold for heating air passing therethrough, said condenser heat exchanger unit connecting to an air inlet of said heater. 
     
     
         3 . The vented laundry dryer of  claim 1  wherein the third casing portion is at least in part below the evaporator heat exchanger unit and further comprises a water condensate reservoir. 
     
     
         4 . The vented laundry dryer of  claim 3  further comprising a water pump arranged to expel water condensate from said reservoir. 
     
     
         5 . The vented laundry dryer of  claim 1  wherein the condenser and evaporator heat exchanger units comprise substantially identical heat exchanger core assemblies. 
     
     
         6 . The vented laundry dryer of  claim 5  wherein the heat exchanger core assemblies each have a generally rectangular box shape. 
     
     
         7 . The vented laundry dryer of  claim 1  wherein the condenser heat exchanger unit is angularly offset with respect to the evaporator heat exchanger unit. 
     
     
         8 . The vented laundry dryer of  claim 1  wherein the condenser heat exchanger unit is angularly offset with respect to the evaporator heat exchanger unit in a horizontal plane. 
     
     
         9 . The vented laundry dryer of  claim 1  wherein the condenser heat exchanger unit is angularly offset with respect to the evaporator heat exchanger unit in a vertical plane. 
     
     
         10 . The vented laundry dryer of  claim 1  wherein the condenser and evaporator heat exchanger units are angularly offset relative to each other in both a horizontal plane and a vertical plane. 
     
     
         11 . The vented laundry dryer of  claim 1  wherein the condenser and evaporator heat exchanger units are attached to each other in parallel in a plane angularly offset with respect to a vertical plane. 
     
     
         12 . The vented laundry dryer of  claim 1  further comprising at least one support structure serving to attach a portion of the coolant circuit to one of the first, second, or third casing portions. 
     
     
         13 . The vented laundry dryer of  claim 1  further comprising a cooling fan for the compressor, wherein the cooling fan is attached to at least one of the first, second, or third casing portions by an intermediate support structure. 
     
     
         14 . The vented laundry dryer of  claim 1  wherein the second and third casing portions form an inlet configured to connect to the outlet of the process air fan. 
     
     
         15 . A heat pump subassembly for a dryer with a process air fan, and a drum, the heat pump subassembly comprising:
 a condenser heat exchanger unit having an air inlet and outlet; and   an evaporator heat exchanger unit having an air inlet and outlet;   wherein said condenser heat exchanger unit comprises a condenser heat exchanger core assembly enclosed in a first casing portion and a second casing portion, and wherein the evaporator heat exchanger unit comprises an evaporator heat exchanger core assembly enclosed by the second casing portion and a third casing portion; and   wherein the first, second, and third casing portions are configured to stack the condenser and evaporator heat exchanger core assemblies one on top of the other.   
     
     
         16 . The heat pump subassembly of  claim 15  wherein the first, second, and third casing portions are configured to orient the condenser and evaporator heat exchanger core assemblies in an angularly offset relation 
     
     
         17 . The heat pump subassembly of  claim 15 , further comprising a heater, wherein the air outlet of the condenser heat exchanger unit is adapted for connection to an inlet of said heater. 
     
     
         18 . The heat pump subassembly of  claim 15 , wherein each of said first, second, and third casing portions comprise separately formed sections. 
     
     
         19 . The heat pump subassembly of  claim 18  wherein the first and second casing portions are mated together, and the second and third portions are mated together. 
     
     
         20 . The heat pump subassembly of  claim 15  wherein the third casing portion further comprises a condensate reservoir. 
     
     
         21 . The heat pump subassembly of  claim 20  further comprising a water pump arranged to expel water condensate from the reservoir. 
     
     
         22 . The heat pump subassembly of  claim 15  further comprising an expansion device, wherein at least part of the expansion device is supported within the dryer by a support component attached to at least one of the first, second, or third casing portions. 
     
     
         23 . The heat pump subassembly of  claim 22  wherein at least a portion of the support component is formed integral with one of the first, second, or third casing portions. 
     
     
         24 . The heat pump subassembly of  claim 15  further comprising:
 a compressor; 
 a cooling fan for said compressor; and 
 at least one support component, wherein at least part of the cooling fan is supported by the support component and wherein the support component attaches the cooling fan to at least one of the first, second, or third casing portions. 
 
     
     
         25 . The heat pump subassembly of  claim 24  wherein at least a portion of the support component is formed integral with one of the first, second, or third casing portions.