Method and a device for a conditioning for an aircraft cabin

Abstract

The invention relates to a method and a device for air conditioning for an aircraft cabin ( 30 ) comprising at least two distinct turbomachines ( 1, 2 ), at least one of which is motorised. When the pressure difference between the cabin and the atmosphere is greater than an upper pressure difference threshold, an economy mode is activated, in which the second turbine stage ( 23 ) is supplied exclusively by an air output obtained from the cabin ( 30 ). When the pressure difference is lower than a lower pressure difference threshold, a cold mode is activated, in which the compression stages ( 11, 21 ) of the turbomachines ( 1, 2 ) are connected in series. The drive speed of at least one motor ( 12, 22 ) is adjusted such as to adjust the refrigerating power supplied.

1 . A method for air conditioning to control the temperature and pressure of the air in an aircraft cabin ( 30 ) from at least one source of air ( 15 ), implemented in an air conditioning device comprising: 
 at least one turbine stage ( 13 ,  23 ) for depressurisation/cooling comprising at least one air intake and at least one outlet ( 58 ,  71 ) for depressurised and cooled air, each turbine stage ( 13 ,  23 ) being connected to means ( 11 ,  21 ) for mechanical compression of air, such as to participate in the driving of these means;    drive means ( 12 ,  22 ) with non-pneumatic energy which are connected to the means ( 11 ,  21 ) for compression, such as to participate in the driving of these means;    a pneumatic supply circuit for the cabin with pipes and controlled valves, which is designed to be able to supply the means ( 11 ,  21 ) for compression from an air output obtained from the source of air ( 15 ), to supply at least one turbine stage ( 13 ) from a compressed air output obtained from the means ( 11 ,  21 ) for compression, and to supply at least one air intake ( 33 ) of the cabin ( 30 ) with the air obtained from the air outlet ( 71 ) of at least one turbine stage ( 23 ), and wherein the controlled valves of the pneumatic supply circuit of the cabin are controlled in order to configure the circuit according to an operating mode selected from amongst different operating modes, each of which corresponds to specific characteristics of output and/or temperature and/or pressure of the output of air supplied to the cabin ( 30 ),    wherein the air conditioning device comprises:    at least two distinct turbomachines ( 1 ,  2 ) each comprising a compression stage ( 11 ,  21 ) and a turbine stage ( 13 ,  23 ) connected to the compression stage ( 11 ,  21 ), at least one of the turbomachines being motorised and comprising a motor ( 12 ,  22 ) with non-pneumatic energy connected to the compression stage ( 11 ,  21 );    at least one parameter which is representative of the pressure difference between the air in the cabin and the external atmosphere, known as the pressure difference, is measured;    when the pressure difference measured is greater than an upper pressure difference threshold, an operating mode known as economy mode is activated, in which: 
 the turbine stage, known as the second turbine stage ( 23 ), of at least one of the turbomachines, known as the second turbomachine ( 2 ), is supplied exclusively via means, known as second supply means ( 68 , V 4 ), by an air output obtained from an air outlet (V 12 ) of the cabin ( 30 ), and the pressure of which is, with the exception of losses of load, that of the air pressure which exists in the cabin ( 30 ); and  
 the air outlet ( 71 ) of the second turbine stage ( 23 ) is isolated from the pneumatic supply circuit of the cabin ( 30 ), such that no output of air supplied in the cabin ( 30 ) is obtained from the air outlet ( 71 ) of the second turbine stage ( 23 );  
   when the pressure difference measured is lower than a lower pressure difference threshold, an operating mode known as cold mode is activated, in which the compression stages ( 11 ,  21 ) of the turbomachines ( 1 ,  2 ) are connected in series from the source ( 15 ) of air, and the drive speed of at least one turbomachine ( 1 ,  2 ) motor ( 12 ,  22 ) is adjusted such as to adjust the refrigerating power supplied by the air conditioning device, and wherein the second turbine stage ( 23 ) is incorporated in the pneumatic supply circuit of the cabin ( 30 ).    
     
     
         2 . A method as claimed in  claim 1 , wherein in economy mode the second turbine stage ( 23 ) is supplied by an air output obtained from the cabin ( 30 ) directly via a pipe ( 68 ) and a controlled valve ( 67 ), such as to enter the second turbine stage ( 23 ) at least substantially at the pressure and temperature of the air which exists in the cabin ( 30 ), with the exception of circulation losses.  
     
     
         3 . A method as claimed in  claim 1  or  claim 2 , wherein in cold mode the second turbine stage ( 23 ) is supplied by an air output obtained from the air outlet ( 58 ) of at least one other turbine stage, known as the first turbine stage ( 13 ), this air output reaching the intake ( 66 ) of the second turbine stage ( 23 ) at least substantially at the same pressure as at the outlet ( 58 ) of the first turbine stage ( 13 ), with the exception of losses of load, and the cabin ( 30 ) is supplied with at least a fraction of the output of air obtained from the air outlet ( 71 ) of the second turbine stage ( 23 ).  
     
     
         4 . A method as claimed in  claim 3 , wherein, since the second turbomachine ( 2 ) is motorised, the first turbine stage ( 13 ) belongs to a first motorised turbomachine ( 1 ) comprising a motor ( 12 ) distinct from the motor ( 23 ) of the second turbomachine ( 2 ).  
     
     
         5 . A method as claimed in any one of  claims 1  to  4 , wherein the drive speed of a single turbomachine motor ( 12 ,  22 ) is adjusted.  
     
     
         6 . A method as claimed in any one of  claims 1  to  5 , wherein in cold mode, the second turbine stage ( 23 ) is not supplied by air obtained from the cabin ( 30 ).  
     
     
         7 . A method as claimed in any one of  claims 1  to  6 , wherein the lower pressure difference threshold and/or the upper pressure difference threshold are adjusted such as to adjust the refrigerating power supplied by the air conditioning device.  
     
     
         8 . A method as claimed in any one of  claims 1  to  7 , wherein in economy mode, at least one fraction of the air output from the second turbine stage ( 23 ) is used as a cold source of at least one heat exchanger ( 3 ).  
     
     
         9 . A method as claimed in any one of  claims 1  to  8 , wherein at least in cold mode, the compressed air supplied by the compression stages ( 11 ,  21 ) is cooled by passing it through a cooling circuit of at least one heat exchanger, known as the intermediate exchanger ( 3 ), before it is supplied to the air intake of at least one turbine stage ( 13 ,  23 ) incorporated in the pneumatic supply circuit of the cabin ( 30 ), and wherein, in economy mode, at least one fraction of the air output from the second turbine stage ( 23 ) is used as a cold source for this intermediate exchanger ( 3 ).  
     
     
         10 . An air conditioning device which is designed to control the temperature and pressure of the air in an aircraft cabin ( 30 ) from at least one source of air ( 15 ) comprising: 
 at least one turbine stage ( 13 ,  23 ) for depressurisation/cooling comprising at least one air intake and at least one outlet ( 58 ,  71 ) for depressurised and cooled air, each turbine stage ( 13 ,  23 ) being connected to mechanical means ( 11 ,  21 ) for compression of air, such as to participate in driving the latter;    drive means ( 12 ,  22 ) with non-pneumatic energy which are connected to the means ( 11 ,  21 ) for compression, such as to participate in driving the latter;    a pneumatic circuit to supply the cabin, with pipes and controlled valves, which is designed to be able to supply the means ( 11 ,  21 ) for compression from an air output obtained from the source of air ( 15 ), to supply at least one turbine stage ( 13 ) from a compressed air output obtained from the means ( 11 ,  21 ) for compression, and to supply at least one air intake ( 33 ) of the cabin ( 30 ) with air obtained from the air outlet ( 71 ) of at least one turbine stage ( 23 );    automatic means to control the controlled valves of the pneumatic circuit, which means are designed to configure the pneumatic supply circuit of the cabin ( 30 ) according to different operating modes, each corresponding to specific characteristics of output and/or temperature and/or pressure of the air output supplied to the cabin ( 30 ),    wherein the device comprises:    at least two distinct turbomachines ( 1 ,  2 ) each comprising a compression stage ( 11 ,  21 ) and a turbine stage ( 13 ,  23 ) connected to the compression stage ( 11 ,  21 ), at least one of the turbomachines being motorised and comprising a motor ( 12 ,  22 ) with non-pneumatic energy connected to the compression stage ( 11 ,  21 );    means for measurement of at least one parameter which is representative of the difference, known as the pressure difference, between the air pressure in the cabin ( 30 ) and the external atmospheric pressure;    and wherein the means for automatic control and the pneumatic circuit for supply of the cabin are designed such as:    when the pressure difference measured is higher than an upper pressure threshold, to activate an operating mode, known as the economy mode, in which: 
 the turbine stage, known as the second turbine stage ( 23 ), of at least one of the turbomachines, known as the second turbomachine, is supplied exclusively via means, known as second supply means ( 68 , V 4 ), by an air output obtained from an air outlet (V 12 ) of the cabin ( 30 ), and the pressure of which is, with the exception of losses of load, that of the air pressure which exists in the cabin ( 30 ); and  
 the air outlet ( 71 ) of the second turbine stage ( 23 ) is isolated from the pneumatic supply circuit of the cabin ( 30 ), such that no output of air supplied in the cabin ( 30 ) is obtained from the air outlet ( 71 ) of the second turbine stage ( 23 );  
   when the pressure difference measured is lower than a lower pressure difference threshold, an operating mode known as cold mode is activated, in which the compression stages ( 11 ,  25 ) of the turbomachines ( 1 ,  2 ) are connected in series from the source of air ( 15 ), and the drive speed of at least one turbomachine ( 1 ,  2 ) motor ( 12 ,  22 ) is adjusted such as to adjust the refrigerating power supplied by the air conditioning device, and wherein the second turbine stage ( 23 ) is incorporated in the pneumatic supply circuit of the cabin ( 30 ).    
     
     
         11 . A device as claimed in  claim 10 , wherein the second supply means ( 68 , V 4 ) consist of a pipe ( 68 ) which connects the air outlet (V 12 ) of the cabin ( 30 ) to an air intake ( 67 ) of the second turbine stage ( 23 ) and of a controlled valve (V 4 ) which is interposed on this pipe ( 68 ), the air supplied to the second turbine stage ( 23 ) by the second supply means ( 68 , V 4 ) in economy mode being, with the exception of circulation losses, at least substantially at the pressure and temperature of the air which exists in the cabin ( 30 ).  
     
     
         12 . A device as claimed in  claim 10  or  claim 11 , wherein in cold mode, the second turbine stage ( 23 ) is supplied via means, known as first supply means ( 59 ,  62 ,  63 ,  64 ,  65 , V 2 , V 3 ), by an air output obtained from the air outlet ( 58 ) of at least one other turbine stage, known as the first turbine stage ( 13 ), and the pneumatic circuit (V 2 ,  63 ,  64 , V 6 , V 13 ,  65 , V 3 ,  72 ,  73 , V 8 ,  78 ) for supply to the cabin supplies the cabin ( 30 ) with at least one fraction of the air output obtained from the air outlet ( 71 ) of the second turbine stage ( 23 ).  
     
     
         13 . A device as claimed in  claim 12 , wherein the second turbomachine ( 2 ) is motorised and the first turbine stage ( 23 ) belongs to a first motorised turbomachine ( 1 ) comprising a motor ( 12 ) which is distinct from the motor ( 23 ) of the second turbomachine ( 2 ).  
     
     
         14 . A device as claimed in any one of  claims 10  to  13 , wherein the second turbomachine ( 2 ) is motorised and the automatic means for control are designed to adjust the drive speed of a single turbomachine motor ( 12  or  22 ).  
     
     
         15 . A device as claimed in any one of  claims 10  to  14 , wherein in cold mode, the second turbine stage ( 23 ) is not supplied by the second supply means ( 68 , V 4 ).  
     
     
         16 . A device as claimed in any one of  claims 10  to  15 , wherein the first supply means ( 59 ,  62 ,  63 ,  64 ,  65 , V 2 , V 3 ) are designed to supply in cold mode to the intake ( 66 ) of the second turbine stage ( 23 ) an air output which is at least substantially, with the exception of losses of load, at the air pressure at the outlet ( 58 ) of the first turbine stage ( 13 ).  
     
     
         17 . A device as claimed in any one of  claims 10  to  16 , wherein the means for automatic control are designed to adjust the lower pressure difference threshold and/or the upper pressure difference threshold such as to adjust the refrigerating power supplied by the air conditioning device.  
     
     
         18 . A device as claimed in any one of  claims 10  to  17 , wherein the device comprises means (V 8 ,  75 ) which are designed to supply in economy mode at least one fraction of the air output obtained from the air outlet ( 71 ) of the second turbine stage ( 23 ), to a cold source circuit of at least one heat exchanger ( 3 ).  
     
     
         19 . A device as claimed in any one of  claims 10  to  18 , wherein it comprises: 
 a heat exchanger, known as an intermediate heat exchanger ( 3 ), which is associated thermally with a cold source, this intermediate exchanger ( 3 ) comprising a cooling circuit with an air intake ( 47 ) which is connected to the air outlet ( 45 ) of the mechanical means ( 11 ,  21 ) for compression of air and an outlet ( 48 ) for cooled air;  
 means ( 49 ,  5 ) to supply the output of cooled air obtained from the cooled air outlet ( 48 ) of the intermediate exchanger ( 3 ) to the air intake ( 57 ) of at least one turbine stage ( 13 ) incorporated in the pneumatic supply circuit of the cabin; and  
 means ( 8 ,  75 ) which, in economy mode, are designed to supply at least one fraction of the output of air obtained from the air outlet ( 71 ) of the second turbine stage ( 23 ), to a cold source circuit ( 3   a ) of the intermediate exchanger ( 3 ).  
 
     
     
         20 . A device as claimed in any one of  claims 10  to  19 , wherein it comprises thermal exchange means ( 9 ), comprising a cold source circuit ( 9   a ) which is designed to be interposed, at least in one operating mode, between the air outlet ( 58 ) of the first turbine stage ( 13 ) and the air intake ( 66 ) of the second turbine stage ( 23 ), such as to have an output of refrigerating air passing through it, these thermal exchange means ( 9 ) also being designed to create a flow of calories from the cabin air ( 30 ) to the cold source circuit ( 9   a ).  
     
     
         21 . A device as claimed in any one of  claims 10  to  20 , wherein the turbine stages ( 13 ,  23 ) are disposed such that the pressure of the air supplied by these turbine stages ( 13 ,  23 ) is lowest at the outlet ( 71 ) of the second turbine stage ( 23 ), known as the second low-pressure turbine stage.  
     
     
         22 . A device as claimed in any one of  claims 10  to  21 , wherein the drive means ( 12 ,  22 ) consist of at least one electric motor.  
     
     
         23 . A device as claimed in any one of  claims 10  to  22 , wherein a compression stage ( 4 ) of a motorised turbomachine ( 2 ), known as the low-pressure compression stage ( 21 ), comprises an air intake ( 41 ) which is connected to the external source of air ( 15 ), and at least one other compression stage ( 11 ) of another motorised turbomachine ( 2 ), known as the high-pressure compression stage ( 11 ), comprises an air intake ( 44 ) which is designed to be able to be connected, in at least one operating mode, to an air outlet ( 42 ) of the low-pressure compression stage ( 21 ), such that at least one fraction of the air output obtained from the air outlet ( 42 ) of the low-pressure compression stage ( 21 ) is supplied to the intake ( 44 ) of the high-pressure compression stage ( 11 ), and wherein the second turbine stage ( 23 ) belongs to the motorised turbomachine ( 2 ) comprising the low-pressure compression stage ( 21 ), and participates in driving of the latter in economy mode and in cold mode.  
     
     
         24 . A device as claimed in claims  12  and  23 , wherein the first turbine stage ( 13 ) belongs to the motorised turbomachine ( 1 ) comprising the high-pressure compression stage ( 11 ), and participates in driving of the latter.  
     
     
         25 . A device as claimed in any one of  claims 10  to  24 , wherein it comprises means ( 5 ) for condensation of the water interposed between the air outlet ( 45 ) of the mechanical means ( 11 ,  21 ) for compression of air and the air intake ( 57 ) of the first turbine stage ( 13 ).  
     
     
         26 . A device as claimed in  claim 25 , wherein the means ( 5 ) for condensation comprise a heat exchanger ( 7 ) which is designed to have an air output which passes through it, obtained from the air outlet ( 71 ) of the second turbine stage ( 23 ).