Refrigerant cycle system

Abstract

A refrigerant cycle system includes a primary-side cycle that circulates a first refrigerant, a secondary-side cycle that circulates a second refrigerant, and a cascade heat exchanger that exchanges heat between the first refrigerant and the second refrigerant. The primary-side cycle includes a primary-side connection pipe. The secondary-side cycle includes a secondary-side connection pipe. The primary-side connection pipe includes a primary-side gas connection pipe and a primary-side liquid connection pipe. The secondary-side connection pipe includes a secondary-side gas connection pipe and a secondary-side liquid connection pipe. The pipe diameter of the secondary-side gas connection pipe is smaller than the pipe diameter of the primary-side gas connection pipe, or the pipe diameter of the secondary-side liquid connection pipe is smaller than the pipe diameter of the primary-side liquid connection pipe.

1 . A refrigerant cycle system comprising:
 a primary-side cycle of a vapor compression type, wherein the primary-side cycle circulates a first refrigerant;   a secondary-side cycle of a vapor compression type, wherein the secondary-side cycle circulates a second refrigerant; and   a cascade heat exchanger that exchanges heat between the first refrigerant and the second refrigerant, wherein   the primary-side cycle comprises:
 a heat-source heat exchanger for giving cold or heat to the first refrigerant; and 
 a primary-side connection pipe that connects the cascade heat exchanger and the heat-source heat exchanger, 
   the secondary-side cycle comprises:
 a usage heat exchanger for using the cold or the heat obtained by the second refrigerant from the cascade heat exchanger; and 
 a secondary-side connection pipe that connects the cascade heat exchanger and the usage heat exchanger, 
   the primary-side connection pipe comprises:
 a primary-side gas connection pipe; and 
 a primary-side liquid connection pipe, 
   the secondary-side connection pipe comprises:
 a secondary-side gas connection pipe; and 
 a secondary-side liquid connection pipe, and 
   at least one of the following is satisfied:
 a pipe diameter of the secondary-side gas connection pipe is smaller than a pipe diameter of the primary-side gas connection pipe, and 
 a pipe diameter of the secondary-side liquid connection pipe is smaller than a pipe diameter of the primary-side liquid connection pipe. 
   
     
     
         2 . The refrigerant cycle system according to  claim 1 , wherein
 the second refrigerant is carbon dioxide,   a refrigerating capacity of the secondary-side cycle is 4.5 kW or more and 5.6 kW or less, and   the pipe diameter of the secondary-side gas connection pipe is 5/16 inch.   
     
     
         3 . The refrigerant cycle system according to  claim 1 , wherein
 the second refrigerant is carbon dioxide,   a refrigerating capacity of the secondary-side cycle is 7.1 kW or more and 9.0 kW or less, and   the pipe diameter of the secondary-side gas connection pipe is ⅜ inch.   
     
     
         4 . The refrigerant cycle system according to  claim 1 , wherein
 the second refrigerant is carbon dioxide,   a refrigerating capacity of the secondary-side cycle is 16 kW or more and 22.4 kW or less, and   the pipe diameter of the secondary-side gas connection pipe is ½ inch.   
     
     
         5 . The refrigerant cycle system according to  claim 1 , wherein
 the second refrigerant is carbon dioxide,   a refrigerating capacity of the secondary-side cycle is 5.6 kW or more and 8.0 kW or less, and   the pipe diameter of the secondary-side liquid connection pipe is 3/16 inch.   
     
     
         6 . The refrigerant cycle system according to  claim 1 , wherein
 the second refrigerant is carbon dioxide,   a refrigerating capacity of the secondary-side cycle is 11.2 kW or more and 16 kW or less, and   the pipe diameter of the secondary-side liquid connection pipe is ¼ inch.   
     
     
         7 . The refrigerant cycle system according to  claim 1 , wherein
 the second refrigerant is carbon dioxide,   a refrigerating capacity of the secondary-side cycle is 16 kW or more and 28 kW or less, and   the pipe diameter of the secondary-side liquid connection pipe is 5/16 inch.   
     
     
         8 . The refrigerant cycle system according to  claim 1 , wherein
 the second refrigerant is carbon dioxide,   a refrigerating capacity of the secondary-side cycle is 33.5 kW or more and 45 kW or less, and   the pipe diameter of the secondary-side liquid connection pipe is ⅜ inch.   
     
     
         9 . The refrigerant cycle system according to  claim 1 , wherein
 the second refrigerant is R32,   a refrigerating capacity of the secondary-side cycle is 16 kW or more and 22.4 kW or less, and   the pipe diameter of the secondary-side gas connection pipe is ⅝ inch.   
     
     
         10 . The refrigerant cycle system according to  claim 1 , wherein
 the second refrigerant is R32,   a refrigerating capacity of the secondary-side cycle is 2.8 kW or more and 3.6 kW or less, and   the pipe diameter of the secondary-side liquid connection pipe is 3/16 inch.   
     
     
         11 . The refrigerant cycle system according to  claim 1 , wherein
 the second refrigerant is R32,   a refrigerating capacity of the secondary-side cycle is 14 kW or more and 16 kW or less, and   the pipe diameter of the secondary-side liquid connection pipe is 5/16 inch.   
     
     
         12 . The refrigerant cycle system according to  claim 1 , wherein
 the second refrigerant is R32,   a refrigerating capacity of the secondary-side cycle is 28 kW or more and 33.5 kW or less, and   the pipe diameter of the secondary-side liquid connection pipe is ⅜ inch.   
     
     
         13 . The refrigerant cycle system according to  claim 1 , wherein
 the second refrigerant is R454B,   a refrigerating capacity of the secondary-side cycle is 9.0 kW or more and 11.2 kW or less, and   the pipe diameter of the secondary-side gas connection pipe is ⅝ inch.   
     
     
         14 . The refrigerant cycle system according to  claim 1 , wherein
 the second refrigerant is R454B,   a refrigerating capacity of the secondary-side cycle is 16.0 kW or more and 22.4 kW or less, and   the pipe diameter of the secondary-side gas connection pipe is ¾ inch.   
     
     
         15 . The refrigerant cycle system according to  claim 1 , wherein
 the second refrigerant is R454B,   a refrigerating capacity of the secondary-side cycle is 16 kW or more and 22.4 kW or less, and   the pipe diameter of the secondary-side liquid connection pipe is ⅜ inch.   
     
     
         16 . The refrigerant cycle system according to  claim 1 , wherein
 the second refrigerant is R454B,   a refrigerating capacity of the secondary-side cycle is 45 kW or more and 56 kW or less, and   the pipe diameter of the secondary-side liquid connection pipe is ½ inch.   
     
     
         17 . The refrigerant cycle system according to  claim 1 , wherein
 the second refrigerant is R454B,   a refrigerating capacity of the secondary-side cycle is 85 kW or more and 109 kW or less, and   the pipe diameter of the secondary-side liquid connection pipe is ⅝ inch.   
     
     
         18 . The refrigerant cycle system according to  claim 1 , wherein at least one of the following is satisfied:
 the pipe diameter of the secondary-side gas connection pipe is less than or equal to 90% of the pipe diameter of the primary-side gas connection pipe, and   the pipe diameter of the secondary-side liquid connection pipe is less than or equal to 90% of the pipe diameter of the primary-side liquid connection pipe.   
     
     
         19 . The refrigerant cycle system according to  claim 1 , wherein a compression ratio of the secondary-side cycle is smaller than a compression ratio of the primary-side cycle.