Cooling system

Abstract

The present invention provides a cooling system (1), comprising a receiver tank (2), an evaporator (3), a compressor (4) and a gas cooler (5), wherein the receiver tank (2) comprises a fluid inlet (6), a liquid outlet (7) and a gas outlet (8); the evaporator (3) comprises an evaporator inlet (9) and an evaporator outlet (10), the compressor (4) comprises a compressor inlet (11) and a compressor outlet (12); the gas cooler (5) comprises a cooler inlet (13) and a cooler outlet (14); and the liquid outlet (7) of the receiver tank (2) is connected to the evaporator inlet (9) via a first conduit (15), the evaporator outlet (10) is connected to the compressor inlet (11) via a second conduit (16), the compressor outlet (12) is connected to the cooler inlet (13) via a third conduit (17), and the cooler outlet (14) is connected to the fluid inlet (6) of the receiver via a fourth conduit (18), wherein at least one of the first conduit (15) and the fourth conduit (18) comprises a pressure regulator (19,25), and the gas outlet (8) of the receiver tank is connected to the evaporator inlet (9) via a fifth conduit (20) and a gas flow regulator (21,22), such that a flow of liquid refrigerant in the first conduit (15) may be controlled by operating the gas flow regulator (21,22) during use.

1 . A cooling system, comprising a receiver tank, an evaporator, a compressor and a gas cooler, wherein
 the receiver tank comprises a fluid inlet, a liquid outlet and a gas outlet;   the evaporator comprises an evaporator inlet and an evaporator outlet,   the compressor comprises a compressor inlet and a compressor outlet;   the gas cooler comprises a cooler inlet and a cooler outlet; and   
       the liquid outlet of the receiver tank is connected to the evaporator inlet via a first conduit, the evaporator outlet is connected to the compressor inlet via a second conduit, the compressor outlet is connected to the cooler inlet via a third conduit, and the cooler outlet is connected to the fluid inlet of the receiver via a fourth conduit, wherein 
       at least one of the first conduit and the fourth conduit comprises a pressure regulator, and 
       the gas outlet of the receiver tank is connected to the evaporator inlet via a fifth conduit and a gas flow regulator, such that a flow of liquid refrigerant in the first conduit may be controlled by operating the gas flow regulator during use. 
     
     
         2 . A cooling system according to  claim 1 , wherein the gas flow regulator is arranged such that a lowering of a flow of gaseous refrigerant in the fifth conduit by operating the gas flow regulator will increase the flow of liquid refrigerant in the first conduit. 
     
     
         3 . A cooling system according to  claim 1 , wherein the gas outlet of the receiver tank is connected to the evaporator inlet via the fifth conduit and the gas flow regulator, such that a mixture of gaseous refrigerant from the fifth conduit and liquid refrigerant from the first conduit may enter the evaporator inlet during use. 
     
     
         4 . A cooling system according to  claim 1 , wherein the fifth conduit comprises a first end connected to the gas outlet of the receiver and a second end connected to the first conduit, such that gaseous refrigerant from the gas outlet of the receiver may be mixed with a liquid refrigerant from the liquid outlet of the receiver before entering the evaporator inlet during use. 
     
     
         5 . A cooling system according to  claim 1 , wherein the first conduit and the fifth conduit is connected to the evaporator inlet via a sixth conduit. 
     
     
         6 . A cooling system according to  claim 1 , wherein the gas flow regulator is a two-way valve. 
     
     
         7 . A cooling system according to  claim 1 , wherein the first conduit, the fifth conduit and the evaporator inlet is interconnected by a three-way coupling featuring a first inlet connected to the fifth conduit, a second inlet connected to the first conduit and an outlet connected to the evaporator inlet, wherein the second inlet is arranged at an angle relative to the outlet, such that an ejector effect of a gaseous refrigerant flow from the fifth conduit acting on a liquid refrigerant in the first conduit is minimized during use. 
     
     
         8 . A cooling system according to  claim 9 , wherein the angle is about 90°. 
     
     
         9 . A cooling system according to  claim 1 , wherein the gas flow regulator is a three-way valve. 
     
     
         10 . A cooling system according to  claim 9 , wherein the three-way valve comprises a first inlet connected to the first conduit, a second inlet connected to the fifth conduit and an outlet connected to the evaporator inlet. 
     
     
         11 . A cooling system according to  claim 1 , comprising a first pressure sensor and a first temperature sensor, arranged in the second conduit, and a second pressure sensor and a second temperature sensor, or a pressure transmitter, arranged in the fourth conduit upstream a pressure regulator. 
     
     
         12 . A method of controlling a cooling system, wherein the cooling system comprises comprising a receiver tank, an evaporator, a compressor and a gas cooler, wherein
 the receiver tank comprises a fluid inlet, a liquid outlet and a gas outlet;   the evaporator comprises an evaporator inlet and an evaporator outlet,   the compressor comprises a compressor inlet and a compressor outlet;   the gas cooler comprises a cooler inlet and a cooler outlet; and   the liquid outlet of the receiver tank is connected to the evaporator inlet via a first conduit, the evaporator outlet is connected to the compressor inlet via a second conduit, the compressor outlet is connected to the cooler inlet via a third conduit, and the cooler outlet is connected to the fluid inlet of the receiver via a fourth conduit, wherein   at least one of the first conduit and the fourth conduit comprises a pressure regulator, and   the gas outlet of the receiver is connected to the evaporator inlet via a fifth conduit and a gas flow regulator, and the method comprising the step of:
 increasing a flow of gaseous refrigerant in the fifth conduit by controlling the gas flow regulator to obtain a reduced flow of liquid refrigerant in the first conduit and a reduced cooling capacity in the evaporator; or 
 reducing a flow of gaseous refrigerant in the fifth conduit by controlling the gas flow regulator to obtain an increased flow of liquid refrigerant in the first conduit and an increased cooling capacity in the evaporator. 
   
     
     
         13 . A method according to  claim 12 , wherein the fourth conduit comprises a pressure regulator and the step of increasing the flow of gaseous refrigerant comprises controlling the pressure regulator to decrease the pressure fall between the cooler outlet and the fluid inlet of the receiver tank. 
     
     
         14 . A method according to  claim 12 , wherein the first conduit comprises a pressure regulator and the step of increasing the flow of gaseous refrigerant comprises controlling the pressure regulator to increase the pressure fall over the first conduit. 
     
     
         15 . A method according to  claim 12 , comprising an initial step of:
 measuring the refrigerant temperature in the second conduit to obtain a differential temperature curve relative to the boiling temperature of the liquid refrigerant within the evaporator; and increasing or reducing a flow of gaseous refrigerant in the fifth conduit depending on whether the differential temperature curve shows a falling or rising differential temperature, respectively.