Cooling unit

Abstract

A cooling unit which contains refrigerant for exchanging heat with an object member of cooling includes a refrigerant passage and cooling means. The refrigerant passage allows the refrigerant to circulate therethrough. The cooling means communicates with the refrigerant passage for supplying the refrigerant passage with the refrigerant. The cooling means includes a refrigeration circuit, a compressor, a condenser, decompression means, an evaporator, a refrigerant supply path, a refrigerant return path, refrigerant control means and first pressure control means. The refrigerant control means has an on mode which allows the refrigerant to circulate through the refrigerant passage at a flow rate which enables the refrigerant to maintain gas-liquid two-phase flow by allowing the condenser to communicate with the refrigerant passage, and an off mode which prevents the refrigerant from circulating through the refrigerant passage by preventing the condenser from communicating with the refrigerant passage.

1 . A cooling unit containing refrigerant for exchanging heat with an object member of cooling, the cooling unit comprising: 
 a refrigerant passage which allows the refrigerant to circulate therethrough;    cooling means communicating with the refrigerant passage for supplying the refrigerant passage with the refrigerant, the cooling means comprising: 
 a refrigeration circuit which allows the refrigerant to circulate therethrough;  
 a compressor disposed in the refrigeration circuit;  
 a condenser also disposed in the refrigeration circuit;  
 decompression means also disposed in the refrigeration circuit;  
 an evaporator also disposed in the refrigeration circuit;  
 a refrigerant supply path one end of which is connected to a part of the refrigeration circuit between the condenser and the decompression means and the other end of which is connected to an inlet of the refrigerant passage;  
 a refrigerant return path one end of which is connected to an outlet of the refrigerant passage and the other end of which is located downstream from the decompression means and is connected to a part of the refrigeration circuit between the decompression means and the compressor;  
 refrigerant control means disposed in the refrigerant supply path for allowing the condenser to communicate with the refrigerant passage or preventing the condenser from communicating with the refrigerant passage; and  
 first pressure control means also disposed in the refrigerant supply path for controlling pressure in the refrigerant passage, wherein the refrigerant control means has an on mode which allows the refrigerant to circulate through the refrigerant passage at a flow rate which enables the refrigerant to maintain gas-liquid two-phase flow by allowing the condenser to communicate with the refrigerant passage, and an off mode which prevents the refrigerant from circulating through the refrigerant passage by preventing the condenser from communicating with the refrigerant passage.  
   
   
   
       2 . The cooling unit according to  claim 1 , further comprising temperature detection means for detecting temperature of the object member or vicinity of the object member, wherein when detection value detected by the temperature detection means rises to or above a first predetermined temperature, the refrigerant control means is put into the on mode, and wherein when the detection value detected by the temperature detection means drops to or below a second predetermined temperature which is lower than the first predetermined temperature, the refrigerant control means is put into the off mode.  
   
   
       3 . The cooling unit according to  claim 1 , further comprising temperature detection means for detecting temperature of the object member or vicinity of the object member, wherein when detection value detected by the temperature detection means rises to or above a first predetermined temperature, the refrigerant control means is put into the on mode for a predetermined time.  
   
   
       4 . The cooling unit according to  claim 1 , further comprising temperature detection means for detecting temperature of the object member or vicinity of the object member, wherein the refrigerant control means sets a duty ratio which represents a ratio of on mode time to total time of the on mode time and off mode time with the total time kept at a constant time and at the same time changes the duty ratio on the basis of detection value detected by the temperature detection means thereby to allow the condenser to communicate with the refrigerant passage or to prevent the condenser from communicating with the refrigerant passage in accordance with the duty ratio.  
   
   
       5 . The cooling unit according to  claim 4 , wherein when the detection value detected by the temperature detection means rises to or above a first predetermined temperature, the refrigerant control means raises the duty ratio on the basis of difference between the detection value and the first predetermined temperature, and when the detection value detected by the temperature detection means drops to or below a second predetermined temperature which is lower than the first predetermined temperature, the refrigerant control means lowers the duty ratio on the basis of difference between the detection value and the second predetermined temperature.  
   
   
       6 . The cooling unit according to  claim 1 , wherein the refrigerant control means is an on-off valve for allowing the refrigerant to circulate through the refrigerant supply path or preventing the refrigerant from circulating through the refrigerant supply path.  
   
   
       7 . The cooling unit according to  claim 1 , wherein the refrigerant control means is a three-way valve for allowing the condenser to communicate with any one of the refrigerant passage and the decompression means.  
   
   
       8 . The cooling unit according to  claim 1 , further comprising gas-liquid separation means upstream from the refrigerant control means in the refrigerant supply path for separating the refrigerant into liquid refrigerant and gas refrigerant.  
   
   
       9 . The cooling unit according to  claim 1 , further comprising second pressure control means disposed in the refrigerant return path, wherein a first accumulator is disposed upstream from the second pressure control means in the refrigerant return path.  
   
   
       10 . The cooling unit according to  claim 9 , wherein the other end of the refrigerant return path is connected to a part of the refrigeration circuit between the decompression means and the evaporator.  
   
   
       11 . The cooling unit according to  claim 9 , wherein the other end of the refrigerant return path is connected to a part of the refrigeration circuit between the evaporator and the compressor, and wherein a second accumulator is disposed in a part of the refrigerant return path and the refrigeration circuit between the second pressure control means and the compressor.  
   
   
       12 . The cooling unit according to  claim 1 , further containing cooling water for exchanging heat with the refrigerant in the condenser, wherein the cooling water exchanges heat with the refrigerant in the evaporator.  
   
   
       13 . The cooling unit according to  claim 1 , wherein the first pressure control means also serves as the refrigerant control means.  
   
   
       14 . The cooling unit according to  claim 1 , further comprising a constant pressure valve disposed in the refrigerant return path for controlling pressure in the refrigerant passage.