Vehicle air conditioning systems comprising refrigerant recovery vessels and methods for operating such systems

Abstract

An air conditioning system for a vehicle including a vapor compression-type refrigerating cycle and using combustible refrigerant includes a refrigerant recovery vessel in communication with a gas-liquid separator and which of recovers the combustible refrigerant by the communication with the gas-liquid separator, and a valve which controls the communication between the refrigerant recovery vessel and the gas-liquid separator in response to an external signal. When combustible refrigerant is used as refrigerant of a vapor compression-type, refrigerating cycle, leakage of the refrigerant may be reduced, minimized, or eliminated, and the recovery of the refrigerant may be carried out readily and efficiently without requiring significant changes to the system configuration.

1 . An air conditioning system for vehicles comprising a vapor compression-type, refrigerating cycle, which uses combustible refrigerant and comprises a gas-liquid separator, comprising; 
 a refrigerant recovery vessel in communication with said gas-liquid separator and which recovers said combustible refrigerant in said refrigerating cycle by the communication with said gas-liquid separator; and    a valve which controls the communication between said refrigerant recovery vessel and said gas-liquid separator in response to an external signal.    
   
   
       2 . The air conditioning system of  claim 1 , wherein said gas-liquid separator and said refrigerant recovery vessel are integral to each other.  
   
   
       3 . The air conditioning system of  claim 2 , wherein said valve is integral with said gas-liquid separator and said refrigerant recovery vessel.  
   
   
       4 . The air conditioning system of  claim 1 , wherein a communication path for communicating between said gas-liquid separator and said refrigerant recovery vessel is disposed at a position outside of said gas-liquid separator and said refrigerant recovery vessel, and said valve is disposed in said communication path.  
   
   
       5 . The air conditioning system of  claim 1 , wherein a time period for recovering refrigerant by opening said valve is set at a predetermined time period, and after expiration of said predetermined time period, recovered refrigerant is enclosed by closing said valve.  
   
   
       6 . The air conditioning system of  claim 1 , further comprising a pressure detecting device, which detects a pressure in said refrigerant recovery vessel or in said gas-liquid separator, and when refrigerant is recovered by opening said valve, said valve is closed in accordance with a detected pressure by said pressure detecting device.  
   
   
       7 . The air conditioning system of  claim 6 , wherein said valve is closed when a detected pressure by of said pressure detecting device equals a predetermined pressure.  
   
   
       8 . The air conditioning system of  claim 1 , further comprising a vehicle collision detection device, which detects or predicts a vehicle collision, and when the vehicle collision is detected or predicted by said vehicle collision detection device, refrigerant in said gas-liquid separator is recovered into said refrigerant recovery vessel by opening said valve.  
   
   
       9 . The air conditioning system of  claim 1 , further comprising a refrigerant leakage detection device, which detects a leakage of refrigerant in said refrigerating cycle, and when the refrigerant leakage is detected by said refrigerant leakage detection device, refrigerant in said gas-liquid separator is recovered into said refrigerant recovery vessel by opening said valve.  
   
   
       10 . The air conditioning system of  claim 1 , wherein, when refrigerant in said gas-liquid separator is recovered into said refrigerant recovery vessel by opening said valve, a main controller stops a compressor provided in said refrigerating cycle.  
   
   
       11 . The air conditioning system of  claim 1 , wherein said valve is a valve driven by an electromagnetic solenoid and said normally, closed-type valve is opened when said electromagnetic solenoid is energized.  
   
   
       12 . A method for controlling leakage of refrigerant in an air conditioning system for vehicles comprising a gas-liquid separator, a refrigerant recovery vessel, and a selectively openable communication path therebetween, said method comprising the steps of: 
 preselecting a predetermined parameter for stopping refrigerant recovery;    detecting a leakage of refrigerant within a refrigerant circuit of said air conditioning system;    opening said communication path between said liquid-gas separator and said refrigerant recovery vessel; and    closing said communication path when a measured parameter equals or exceeds said predetermined parameter.    
   
   
       13 . The method of  claim 12 , wherein said predetermined parameter is a predetermined time period during which said communication path is open.  
   
   
       14 . The method of  claim 12 , wherein said predetermined parameter is a predetermined pressure within said refrigerant recovery vessel, such that said communication path is open when an pressure measured within said refrigerant recovery vessel is less than said predetermined pressure.  
   
   
       15 . The method of  claim 12 , wherein said air conditioning system comprises a compressor, and the method further comprises the step of stopping said compressor when said communication path is open.  
   
   
       16 . A method for controlling leakage of combustible refrigerant in an air conditioning system for vehicles comprising a gas-liquid separator, a refrigerant recovery vessel, and a selectively openable communication path therebetween, said method comprising the steps of: 
 preselecting a predetermined parameter for stopping refrigerant recovery;    detecting or predicting a vehicle collision;    opening said communication path between said liquid-gas separator and said refrigerant recovery vessel; and    closing said communication path when a measured parameter equals or exceeds said predetermined parameter.    
   
   
       17 . The method of  claim 16 , wherein said predetermined parameter is a predetermined time period during which said communication path is open.  
   
   
       18 . The method of  claim 16 , wherein said predetermined parameter is a predetermined pressure within said refrigerant recovery vessel, such that said communication path is open when a pressure measured within said refrigerant recovery vessel is less than said predetermined pressure.  
   
   
       19 . The method of  claim 16 , wherein said air conditioning system comprises a compressor and the method further comprises the step of stopping said compressor when said communication path is open.