A vapour compression system with a suction line liquid separator

Abstract

A method for controlling a vapour compression system (1) is disclosed. The vapour compression system (1) comprises an ejector (6) and a liquid separating device (10) arranged in a suction line. A liquid level sensor (18) is arranged in the liquid separating device (10). A liquid level in the liquid separating device (10) is monitored by means of the liquid level sensor (18). In the case that the liquid level in the liquid separating device (10) is above a predefined threshold level, a control parameter of the vapour compression system (1) is adjusted in order to increase a flow rate of refrigerant from the liquid separating device (10) to the secondary inlet (15) of the ejector (6) and/or decrease a flow rate of liquid refrigerant from the evaporator(s) (9) to the liquid separating device (10).

What is claimed is: 
     
         1 - 7 . (canceled) 
     
     
         8 . A method for controlling a vapour compression system, the vapour compression system comprising a compressor unit, a heat rejecting heat exchanger, an ejector, a receiver, at least one expansion device and at least one evaporator arranged in a refrigerant path, the vapour compression system further comprising a liquid separating device arranged in a suction line of the vapour compression system and a liquid level sensor arranged in the liquid separating device, the liquid separating device comprising a gaseous outlet connected to the inlet of the compressor unit and a liquid outlet connected to a secondary inlet of the ejector, the method comprising the steps of:
 monitoring a liquid level in the liquid separating device by means of the liquid level sensor, and   in the case that the liquid level in the liquid separating device is above a predefined threshold level, adjusting a control parameter of the vapour compression system in order to decrease a flow rate of liquid refrigerant from the evaporator(s) to the liquid separating device by, for at least some of the evaporator(s), selecting a positive setpoint for a superheat value and/or reducing a maximum allowable opening degree of the expansion device(s), thereby preventing said evaporator(s) from being operated in a flooded state.   
     
     
         9 . The method according to  claim 8 , wherein the step of adjusting a control parameter further comprises adjusting a control parameter of the vapour compression system in order to increase a flow rate of refrigerant from the liquid separating device to the secondary inlet of the ejector. 
     
     
         10 . The method according to  claim 8 , wherein the step of adjusting a control parameter of the vapour compression system comprises adjusting a pressure and/or a temperature prevailing in the vapour compression system. 
     
     
         11 . The method according to  claim 10 , wherein the step of adjusting a control parameter of the vapour compression system comprises reducing a pressure prevailing inside the receiver. 
     
     
         12 . The method according to  claim 10 , wherein the step of adjusting a control parameter of the vapour compression system comprises increasing a pressure of refrigerant leaving the heat rejecting heat exchanger and entering the primary inlet of the ejector. 
     
     
         13 . The method according to  claim 10 , wherein the step of adjusting a control parameter of the vapour compression system comprises decreasing a pressure prevailing in the suction line of the vapour compression system. 
     
     
         14 . The method according to  claim 10 , wherein the step of adjusting a control parameter of the vapour compression system comprises increasing a temperature of refrigerant leaving the heat rejecting heat exchanger and entering the primary inlet of the ejector. 
     
     
         15 . The method according to  claim 9 , wherein the step of adjusting a control parameter of the vapour compression system comprises adjusting a pressure and/or a temperature prevailing in the vapour compression system. 
     
     
         16 . The method according to  claim 11 , wherein the step of adjusting a control parameter of the vapour compression system comprises increasing a pressure of refrigerant leaving the heat rejecting heat exchanger and entering the primary inlet of the ejector. 
     
     
         17 . The method according to  claim 11 , wherein the step of adjusting a control parameter of the vapour compression system comprises decreasing a pressure prevailing in the suction line of the vapour compression system. 
     
     
         18 . The method according to  claim 12 , wherein the step of adjusting a control parameter of the vapour compression system comprises decreasing a pressure prevailing in the suction line of the vapour compression system. 
     
     
         19 . The method according to  claim 11 , wherein the step of adjusting a control parameter of the vapour compression system comprises increasing a temperature of refrigerant leaving the heat rejecting heat exchanger and entering the primary inlet of the ejector. 
     
     
         20 . The method according to  claim 12 , wherein the step of adjusting a control parameter of the vapour compression system comprises increasing a temperature of refrigerant leaving the heat rejecting heat exchanger and entering the primary inlet of the ejector.