Patent Publication Number: US-2012031127-A1

Title: Defrost Fan Control Device

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a defrost fan control device. More particularly, this invention relates to a defrost fan control device. 
     A refrigerator cools down the temperature of a storage space. During the operation, the temperature difference is unavoidable between the storage space and its outside. This temperature difference results in frost and ice formed in the storage space. Such frost and ice need to be removed or molten away now and then to facilitate the cooling effect of the refrigerator. 
     A couple of devices have been suggested to solve the problem, but always there was one or more shortcomings. One of the major problem was a waste of energy. 
     Accordingly, a need for a more efficient and more defrost fan control device for refrigerators has been present for a long time considering the tendency of growing in capacity of refrigerator. This invention is directed to solve these problems and satisfy the long-felt need. 
     SUMMARY OF THE INVENTION 
     The present invention contrives to solve the disadvantages of the prior art. 
     An object of the invention is to provide a defrost fan control device for a refrigerator. 
     Another object of the invention is to provide a defrost fan control device that is highly efficient. 
     Still another object of the invention is to provide a defrost fan control device, in which the frost and ice can be removed without energy waste. 
     An aspect of the invention provides a defrost fan control device for a refrigerator, in which the refrigerator includes a storage space that is cooled by refrigerant flowing through an evaporator, a compressor, and a condenser. 
     The defrost fan control device comprises a defrost fan, a defrost heater, a defrost thermostat, and a defrost timer. 
     The defrost fan is configured for blowing off moisture from the storage space. 
     The defrost heater is disposed in a vicinity of the evaporator and configured for melting frost and ice melt away from the evaporator. 
     The defrost thermostat is disposed in a vicinity of the evaporator and configured for ending a defrosting process by the defrost fan and the defrost heater when the temperature in a vicinity of the evaporator falls into a predetermined range of temperature. 
     The defrost timer is for turning off a cooling process and turning on the defrosting process for predetermined time periods. 
     The defrost fan, the defrost heater, or the defrost fan and the defrost heater operate when the compressor operates. 
     The operations of the defrost fan, the defrost heater, or the defrost fan and the defrost heater are controlled by the defrost timer independently from the operation of the compressor. 
     The defrost fan may be disposed in the storage space. 
     The defrost heater may be disposed at locations where frost and ice form in the storage space. 
     A substantial amount of the frost and ice may melt away when the temperature in the vicinity of the evaporator falls into the predetermined range of temperature. 
     The defrost fan control device may further comprise a frost-ice sensor for detecting frost and ice formed at the locations. 
     The defrost fan and the defrost heater may be configured to operate when the frost-ice sensor detects frost or ice at the locations. 
     The defrost timer may be configured for operating the defrost fan and the defrost heater periodically with a first time period. 
     The first time period may comprise about one, two, three, four, five, six, seven, eight, nine, ten, eleven, twelve, and twenty four hours. 
     The defrost timer may be configured to operate the defrost fan and the defrost heater for a plurality of second time periods. 
     The plurality of second time periods may be predetermined according to temporal change and statistics of operation, energy consumption, load of the refrigerator. 
     The defrost timer may be configured to set the time periods and frequency of the time periods. 
     The defrost fan control device may further comprise a information storing device for recording operation parameters of the refrigerator. 
     The operation parameters may comprise an operation time of the defrost fan and the defrost heater, a state of the defrost thermostat, an ambient temperature, a temperature in the storage space, and a date-and-time. 
     The advantages of the present invention are: (1) the defrost fan control device increases the efficiency of the refrigerator; (2) the defrost fan control device gets rid of frost and ice effectively under various operational circumstances. 
     Although the present invention is briefly summarized, the fuller understanding of the invention can be obtained by the following drawings, detailed description and appended claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and other features, aspects and advantages of the present invention will become better understood with reference to the accompanying drawings, wherein: 
         FIG. 1  is a schematic diagram showing a refrigerator; 
         FIG. 2  is a block diagram showing a defrost fan control device according to an embodiment of the invention; 
         FIG. 3  is a block diagram showing another defrost fan control device according to another embodiment of the invention; 
         FIG. 4  is a block diagram showing a network of a plurality of defrost fan control devices according to still another embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     An aspect of the invention provides a defrost fan control device  100  for a refrigerator  90 , in which the refrigerator  90  includes a storage space that is cooled by refrigerant flowing through an evaporator  92 , a compressor  94 , and a condenser  96 . 
     The defrost fan control device  100  comprises a defrost fan  10 , a defrost heater  20 , a defrost thermostat  30 , and a defrost timer  40 . 
     The defrost fan  10  is configured for blowing off moisture from the storage space  92 . Especially, the defrost fan  10  blows the moisture formed in the cooling process off portions where frost and ice may form. 
     The defrost heater  20  is disposed in a vicinity of the evaporator  92  and configured for melting frost and ice melt away from the evaporator  92  and portions on which the frost and ice formed. The defrost heater  20  may be located close to those locations where the frost and ice may form easily. The defrost heater  20  may comprise electric wire with high resistance and may be powered by electricity drawn from outside. 
     The defrost thermostat  30  is disposed in a vicinity of the evaporator  92  and configured for ending a defrosting process by the defrost fan  10  and the defrost heater  20  when the temperature in a vicinity of the evaporator  92  falls into a predetermined range of temperature. The defrost thermostat  30  may work as an electrical path which connects the defrost fan  10  and the defrost heater  20  with power supply (not shown). 
     The defrost timer  40  is for turning off a cooling process by the evaporator  92  and turning on the defrosting process by the defrost fan  10  and the defrost heater  20  for predetermined time periods. 
     The defrost fan  10 , the defrost heater  20 , or the defrost fan  10  and the defrost heater  20  operate when the compressor  94  operates. 
     The operations of the defrost fan  10 , the defrost heater  20 , or the defrost fan  10  and the defrost heater  20  together may be controlled by the defrost timer  40  independently from the operation of the compressor  94 . 
     That is, the defrosting process may or may not be associated with the operation of the compressor  94 . 
     The defrost fan  10  may be disposed in the storage space  91 . 
     The defrost heater  20  may be disposed at locations where frost and ice form in the storage space  91 . 
     A substantial amount of the frost and ice may melt away when the temperature in the vicinity of the evaporator falls into the predetermined range of temperature due to the operation of the defrost heater  20 . 
     The defrost fan control device  100  may further comprise one or more frost-ice sensors  50  for detecting frost and ice formed at the locations. The one or more frost-ice sensors  50  may detect the forming of the frost and ice electrically or optically. 
     The defrost fan  10  and the defrost heater  20  may be configured to operate when the frost-ice sensor  50  detects frost or ice at the locations. Each of the defrost fan  10  and the defrost heater  20  is electrically connected with the frost-ice sensors  50 . 
     The defrost timer  40  may be configured for operating the defrost fan  10  and the defrost heater  20  periodically with a first time period. 
     The first time period may comprise about one, two, three, four, five, six, seven, eight, nine, ten, eleven, twelve, and twenty four hours. 
     The defrost timer  40  may be configured to operate the defrost fan  10  and the defrost heater  20  for a plurality of second time periods. 
     The plurality of second time periods may be predetermined according to temporal change and statistics of operation, energy consumption, load of the refrigerator  90 , such that the defrost timer may be set with different operation time determined by day, night, season, and geographical location of operation. 
     The defrost timer  40  may be configured to set the time periods and frequency of the time periods. 
     The defrost fan control device  100  may further comprise a information storing device  60  for recording operation parameters of the refrigerator  90  as shown in  FIG. 3 . 
     The operation parameters may comprise an operation time of the defrost fan  10  and the defrost heater  20 , a state of the defrost thermostat  30 , an ambient temperature, a temperature in the storage space  91 , and a date-and-time of the operation of the refrigerator  90 . 
     Furthermore, the defrost fan control device  100  may further comprise an information processing device  70  including a computer as shown in  FIG. 3 . 
     In another aspect of the invention, a plurality of refrigerators  90 , each of which including defrost fan control device  100 , may form a network through the Internet  900  and controlled by a server  80  as shown in  FIG. 4 . 
     While the invention has been shown and described with reference to different embodiments thereof, it will be appreciated by those skilled in the art that variations in form, detail, compositions and operation may be made without departing from the spirit and scope of the invention as defined by the accompanying claims.