Refrigerator

Abstract

A refrigerator for cooling a space inside thereof with a Stirling refrigerating engine includes state detection means for detecting an excessive cooling critical state of the Stirling refrigerating engine and excessive cooling prevention means for preventing excessive cooling of the Stirling refrigerating engine based on detection of the excessive cooling critical state by the state detection means. Excessive cooling of the Stirling refrigerating engine can thus be prevented.

1 . A refrigerator ( 1 ) for cooling a space inside the refrigerator with a Stirling refrigerating engine ( 30 ), comprising:
 state detection means ( 81 , S 01 , S 1 , S 21 , S 31 , S 37 , S 39 , S 45 , S 74 , S 75 , S 82 , S 84 ) for detecting an excessive cooling critical state of said Stirling refrigerating engine; and   excessive cooling prevention means (S 02 ) for preventing excessive cooling of said Stirling refrigerating engine based on detection of said excessive cooling critical state by said state detection means.   
   
   
       2 . The refrigerator according to  claim 1 , further comprising:
 door state detection means ( 82 ,  83 ) for detecting an open/close state of a door ( 14 ,  15 ) of a cooling chamber ( 11 ,  12 ) of said refrigerator;   a cooling fan ( 22 ) supplying cold air cooled by said Stirling refrigerating engine into the space inside; and   cooling fan control means (S 22 ) for stopping said cooling fan while a door open state is detected by said door state detection means; and   said state detection means detecting that a prescribed time period has elapsed since detection of the door open state by said door state detection means (S 23 ).   
   
   
       3 . The refrigerator according to  claim 2 , further comprising:
 a first cooling chamber ( 12 ) and a second cooling chamber ( 11 ) partitioned by a heat insulator and each having the door; said first cooling chamber being supplied with cold air cooled by said Stirling refrigerating engine by said cooling fan;   an air passage ( 20 ,  21 ,  21 A) for guiding the cold air cooled by said Stirling refrigerating engine to said second cooling chamber;   shut-off means ( 61 ) provided in said air passage, for shutting off the cold air cooled by said Stirling refrigerating engine; and   a blowing fan ( 62 ) sending the cold air cooled by said Stirling refrigerating engine to said air passage; wherein   when said door state detection means detects a closed state of the door of said first cooling chamber and an open state of the door of said second cooling chamber (S 31 ), said excessive cooling prevention means causes said shut-off means to shut off said air passage (S 35 ) and cancels stopped state of said cooling fan and drives said cooling fan (S 36 ), and when said door state detection means detects an open state of the door of said first cooling chamber and a closed state of the door of said second cooling chamber (S 39 ), said excessive cooling prevention means causes said shut-off means to cancel shut-off of said air passage (S 43 ) and drives said blowing fan (S 44 ).   
   
   
       4 . The refrigerator according to  claim 1 , further comprising a low-temperature side evaporator ( 42 ) receiving cold heat from a low-temperature portion formed in said Stirling refrigerating engine through a secondary coolant; wherein
 said state detection means includes temperature detection means ( 81 ) for detecting a temperature of said low-temperature portion, said low-temperature side evaporator, or a low-temperature side condenser ( 41 ) paired with said low-temperature side evaporator, and detects that the temperature detected by said temperature detection means is lower than a prescribed temperature (S 01 , S 11 , S 74 , S 82 , S 84 ).   
   
   
       5 . The refrigerator according to  claim 4 , wherein
 said excessive cooling prevention means carries out, prior to stop control (S 24 , S 86 ) for controlling and stopping said Stirling refrigerating engine, excessive cooling prevention control (S 22 , S 78 , S 81 ) different from said stop control, for preventing excessive cooling of said Stirling refrigerating engine.   
   
   
       6 . The refrigerator according to  claim 5 , wherein
 said prescribed temperature includes a first temperature (T 1 ) higher than a temperature at which said Stirling refrigerating engine is excessively cooled and a second temperature (T 2 ) higher than the temperature at which said Stirling refrigerating engine is excessively cooled and lower than said first temperature, and   when said state detection means detects that the temperature detected by said temperature detection means is lower than said first temperature, said excessive cooling prevention means carries out said excessive cooling prevention control, and when said coolant state detection means detects that the temperature detected by said temperature detection means is lower than said second temperature, said excessive cooling prevention means carries out said stop control.   
   
   
       7 . The refrigerator according to  claim 4 , further comprising:
 abnormality in temperature detection sensing means ( 81 ) for sensing abnormality in detection of a temperature by said temperature detection means, when said temperature detection means detects a temperature.   
   
   
       8 . The refrigerator according to  claim 4 , further comprising:
 a cooling fan ( 22 ) supplying cold air cooled by said low-temperature side evaporator into the space inside; wherein   said excessive cooling prevention means drives said cooling fan (S 13 , S 36 ) or increases a fan level of said cooling fan (S 14 , S 78 ).   
   
   
       9 . The refrigerator according to  claim 8 , wherein
 when said state detection means detects that the temperature detected by said temperature detection means is lower than said first temperature (S 74 ), said excessive cooling prevention means drives said cooling fan or increases a fan level of said cooling fan (S 78 ), and when said state detection means detects that the temperature detected by said temperature detection means is lower than said first temperature (S 82 ) after a prescribed time period has elapsed since drive of said cooling fan or increase in the fan level of said cooling fan (S 79 ), said excessive cooling prevention means controls said Stirling refrigerating engine to lower cooling capability (S 81 ).   
   
   
       10 . The refrigerator according to  claim 8 , wherein
 said excessive cooling prevention means includes revolution number control means ( 90 ) for controlling number of revolutions of said cooling fan, and   when said state detection means detects that the temperature detected by said temperature detection means is lower than said first temperature, said excessive cooling prevention means drives said cooling fan with the number of revolutions of said cooling fan being set to maximum revolution capability (S 78 ), and when said state detection means detects that the temperature detected by said temperature detection means is lower than said first temperature (S 82 ) after a prescribed time period has elapsed since drive of said cooling fan at the maximum number of revolutions (S 79 ), said excessive cooling prevention means controls said Stirling refrigerating engine to lower cooling capability (S 81 ).