Condenser dryer having a heat pump, and method for operating the same

Abstract

A condenser dryer includes a drying chamber for items to be dried; a process-air circuit including a fan; and a heat pump in which a refrigerant circulates. The heat pump has an evaporator and a condenser, with the evaporator or the condenser or both being a heat exchanger having level surfaces and including at least one endlessly folded, flattened tube to form a plurality of rows of meander stacks in laterally offset relationship.

1 - 13 . (canceled) 
     
     
         14 . A condenser dryer, comprising:
 a drying chamber for items to be dried;   a process-air circuit including a fan; and   a heat pump in which a refrigerant circulates, said heat pump having an evaporator and a condenser, said evaporator or said condenser, or both, being a heat exchanger having level surfaces and including at least one endlessly folded, flattened tube to form a plurality of rows of meander stacks in laterally offset relationship.   
     
     
         15 . The condenser dryer of  claim 14 , wherein said flattened tube has at least two hollow chambers extending in a longitudinal direction of the tube. 
     
     
         16 . The condenser dryer of  claim 15 , wherein the flattened tube has three to eight hollow chambers extending in a longitudinal direction of the tube. 
     
     
         17 . The condenser dryer of  claim 14 , wherein the flattened tube is defined by a ratio between a width and height in a range of 4 to 25. 
     
     
         18 . The condenser dryer of  claim 14 , wherein one of the evaporator or condenser, or both, includes at least two endlessly folded, flattened tubes, each tube forming a plurality of rows of mutually laterally offset meander stacks. 
     
     
         19 . The condenser dryer of  claim 18 , wherein each plurality of rows of mutually laterally offset meander stacks of the at least two endlessly folded, flattened tubes have been pushed one into another of said pluralities. 
     
     
         20 . The condenser dryer of  claim 18 , wherein at least two endlessly folded, flattened tubes are connected in parallel. 
     
     
         21 . The condenser dryer of  claim 18 , wherein at least two endlessly folded, flattened tubes are connected in series. 
     
     
         22 . The condenser dryer of  claim 18 , wherein the at least one endlessly folded, flattened tube has a flat surface. 
     
     
         23 . The condenser dryer of  claim 18 , wherein the endlessly folded, flattened tube is located completely in the process-air circuit. 
     
     
         24 . The condenser dryer of  claim 18 , wherein the flattened tube is made of copper or aluminum. 
     
     
         25 . The condenser dryer of  claim 18 , wherein the flattened tube has straight sections and curved sections in at least one meander stack, said straight sections extending in parallel relationship at a distance, with a ratio of the distance between the straight sections and a height of the tube being defined by a range from 1.5 to 10. 
     
     
         26 . A method for operating a condenser dryer having a drying chamber for items requiring to be dried, a process-air circuit, a fan in the process-air circuit, and a heat pump in which a refrigerant circulates, the heat pump having an evaporator, a compressor, a throttle, and a condenser, the evaporator and/or condenser being a heat exchanger, said method comprising the steps of:
 providing level surfaces on the heat exchanger and at least one endlessly folded, flattened tube that forms a plurality of rows of meander stacks in laterally offset relationship;   ducting a refrigerant through the flattened tube; and   ducting the process air over the flattened tube so as to cause an exchange of heat between the refrigerant and the process air.   
     
     
         27 . The method of  claim 26 , wherein a turbulent flow of refrigerant is provided in the step of ducting refrigerant through the flattened tube. 
     
     
         28 . The method of  claim 26 , wherein the refrigerant is ducted by a cross-flow method, relative to the process air. 
     
     
         29 . The method of  claim 26 , wherein a turbulent flow of refrigerant is ducted by a counter-current method, relative to the process air. 
     
     
         30 . The method of  claim 26 , wherein the condenser dryer also has an air-to-air heat exchanger, said method further comprising the step of coordinating the control of the heat pump with the control of the air-to-air heat exchanger so as to keep the temperature of the refrigerant in the heat pump within a predetermined range. 
     
     
         31 . The method of  claim 30 , wherein the step of coordinating control of the heat pump with the control of the air-to-air heat exchanger lessens the heating power of the air-to-air heat exchanger as the degree of dryness of the items requiring to be dried in the condenser dryer advances. 
     
     
         32 . The method of  claim 30 , wherein the step of coordinating control of the heat pump with the control of the air-to-air heat exchanger increases the cooling power of the heat pump as the degree of dryness of the items requiring to be dried in the condenser dryer advances.