Refrigerating equipment

Abstract

In a refrigerating apparatus in which gas refrigerant is injected into suction pipes ( 10 a, 10 b ) of compressors ( 2 A, 2 B) from an oil return passageway ( 21 ) and from a gas injection passageway, a liquid injection passageway ( 15 ) through which liquid refrigerant is injected into the suction side of compressors ( 2 A, 2 B) is provided and, in addition, the oil return passageway ( 21 ) and the gas injection passageway are connected to the liquid injection passageway ( 15 ), thereby making it possible to prevent the occurrence of abnormal noise due to the intermixing of gas refrigerants in the suction pipes ( 10 a, 10 b ).

1 . A refrigerating apparatus in which a refrigerant circuit ( 1 E) which performs a vapor compression refrigerating cycle is provided with an oil return passageway ( 21 ) through which refrigerating machine oil separated on the discharge side of compressors ( 2 A,  2 B) is injected into the suction side of said compressors ( 2 A,  2 B), comprising: 
 a liquid injection passageway ( 15 ) through which liquid refrigerant is injected into the suction side of said compressors ( 2 A,  2 B),    wherein said oil return passageway ( 21 ) is connected to said liquid injection passageway ( 15 ).    
   
   
       2 . A refrigerating apparatus in which a refrigerant circuit ( 1 E) which performs a vapor compression refrigerating cycle is provided with a gas injection passageway ( 37 ) through which gas refrigerant is injected into the suction side of compressors ( 2 A,  2 B), comprising: 
 a liquid injection passageway ( 15 ) through which liquid refrigerant is injected into the suction side of said compressors ( 2 A,  2 B),    wherein said gas injection passageway ( 37 ) is connected to said liquid injection passageway ( 15 ).    
   
   
       3 . The refrigerating apparatus of either  claim 1  or  claim 2 , comprising: 
 a heat source side unit ( 1 A) and utilization side units ( 1 B,  1 C,  1 D), said units ( 1 A,  1 B,  1 C,  1 D) being connected with one another,    wherein the degree of superheat of suction refrigerant of said compressors ( 2 A,  2 B) is controlled by adjusting the rate of flow of refrigerant flowing through said liquid injection passageway ( 15 ) without operating expansion mechanisms ( 42 ,  52 ) provided in said utilization side units ( 1 B,  1 C,  1 D).    
   
   
       4 . The refrigerating apparatus of  claim 3 , 
 wherein said compressors ( 2 A,  2 B) are variable displacement compressors,    wherein said liquid injection passageway ( 15 ) is opened whenever the operating capacity of said compressors ( 2 A,  2 B) exceeds a predetermined value.