Fluid Compressor with Aerostatic Bearing, Control System of a Compressor with Aerostatic Bearing and Method of Controlling a Compressor with Aerostatic Bearing

Abstract

The present invention relates to a fluid compressor having an aerostatic bearing, to a control system of a fluid compressor having an aerostatic bearing as well as to a method of controlling a compressor, wherein the aerostatic bearing is fed by a compressed fluid accumulator ( 5 ) which is charged during the operation of the compressor ( 100 ) and discharged at the respective start to prevent damage to the bearings. These objectives are achieved by means of a fluid compressor ( 100 ) comprising a pressurization chamber (C) and at least one fluid pressurization device ( 1, 2, 18 ), the pressurization chamber (C) and the pressurization device ( 1, 2, 18 ) being located in a housing ( 4 ), the pressurization chamber (C) having a non-pressurized inlet ( 10 ) and a pressurized outlet ( 20 ), the pressurization device ( 1, 2, 18 ) compressing the fluid collected by the non-pressurized inlet ( 10 ) and discharging it through the pressurized outlet ( 20 ), the pressurization device ( 1 , 2, 18 ) having at least one aerostatic bearing ( 3 ), the aerostatic bearing ( 3 ) comprising a floating pressurization region ( 33 ), the compressor comprising a compressed fluid accumulator ( 5 ) fluidically connectable to the pressurized outlet ( 20 ) and the floating pressurization region ( 33 ), the compressed fluid accumulator ( 5 ) being located inside the housing ( 4 ) of the compressor ( 100 ). A system for controlling a compressor ( 100 ) and the respective control method are further described.

1 . A fluid compressor comprising a pressurization chamber and at least one fluid pressurization device,
 the pressurization chamber and the pressurization device being located in a housing, the pressurization chamber having a non-pressurized inlet and a pressurized outlet, the pressurization device compressing the fluid collected by the non-pressurized inlet and discharging it through the pressurized outlet,   the pressurization device having at least one aerostatic bearing, the aerostatic bearing comprising a floating pressurization region, and   a compressed fluid accumulator fluidically connectable to the pressurized outlet and to the floating pressurization region, the compressed fluid accumulator being located inside the housing of the compressor and being fed with the pressurized outlet fluid.   
   
   
       2 . A compressor according to  claim 1 , characterized in that the housing is formed by closure walls and in that the compressed fluid accumulator is formed as an integral part of the housing and is located internally to the closure walls. 
   
   
       3 . A compressor according to  claim 1 , characterized in that the compressed fluid accumulator is configured to be selectively connectable either to the pressurized outlet or to the floating region of the aerostatic bearing. 
   
   
       4 . A compressor according to  claim 1 , characterized in that the compressed fluid accumulator is connectable to the floating region of the aerostatic bearing through an accumulator tube and a bearing tube, the accumulator tube being connected to the bearing tube through a first control valve, the first control valve being located in the accumulator tube. 
   
   
       5 . A compressor according to  claim 1 , characterized in that the compressed fluid accumulator is connectable to the pressurized outlet through an accumulator tube and a collection piping, the accumulator tube being connected to the collection piping through the first control valve and a second control valve, the second control valve being located in the collection piping. 
   
   
       6 . A compressor according to  claim 4 , characterized in that the first control valve enables the connection of the compressed fluid accumulator to the pressurized outlet when the compressor is operating. 
   
   
       7 . A compressor according to  claim 4 , characterized in that the floating pressurization region of the aerostatic bearing is connected to the pressurized outlet when the compressor is operating. 
   
   
       8 . A compressor according to  claim 4 , characterized in that before the start of the compressor, the compressed fluid accumulator is connected to the floating pressurization region of the aerostatic bearing, the second control valve remaining closed for the passage of the fluid to the pressurized outlet, the compressor being started after the time needed for the aerostatic bearing to float. 
   
   
       9 . A compressor according to  claim 6 , characterized in that the first control valve is an electric valve controllable by a remote system. 
   
   
       10 . A compressor according to  claim 6 , characterized in that the second control valve is a unidirectional valve that enables the passage of the fluid of the pressurized outlet to the compressed fluid accumulator. 
   
   
       11 . A compressor according to  claim 10 , wherein the compressor is a centrifugal compressor and wherein the pressurization device is a rotor, the rotor being associated with a shaft, the shaft having a pair of aerostatic bearings in the floating pressurization region. 
   
   
       12 . A compressor according to  claim 11 , wherein the compressor is a linear compressor and wherein the pressurization device is a piston positioned inside a cylinder, the piston being displaced inside the cylinder and having a pair of aerostatic bearings. 
   
   
       13 . A compressor control system comprising a control circuit to control a fluid compressor, the compressor comprising a pressurization chamber and at least one fluid pressurization device,
 the pressurization chamber and the pressurization device being located in a housing, the pressurization chamber having a non-pressurized inlet and a pressurized outlet, the pressurization device compressing the fluid collected by the non-pressurized inlet and discharging it through the pressurized outlet,   the pressurization device having at least one aerostatic bearing, the aerostatic bearing comprising a floating pressurization region,   a first control valve and a second control valve that selectively connect either a compressed fluid accumulator integrated into the housing to the pressurized outlet or the compressed fluid accumulator to the floating region of the aerostatic bearing,   the system being configured to connect the compressed fluid accumulator to the pressurized outlet and to the floating region of the aerostatic bearing when the compressor is operating, or   to connect only the compressed fluid accumulator to the floating region of the aerostatic bearing before the start of the compressor.   
   
   
       14 . A system according to  claim 13 , characterized in that the first control valve is an electric valve associated with a control circuit, the system being configured in such a way that during the start of the compressor, the control circuit opens the electric valve for transferring the compressed fluid stored inside the compressed fluid accumulator to the floating pressurization region of the aerostatic bearing, the compressor being started after the time needed for the aerostatic bearing to float. 
   
   
       15 . A system according to  claim 14 , characterized in that, during the start of the compressor, the second control valve remains closed for the passage of the fluid to the pressurized outlet, until the pressure of the fluid of the pressurized outlet is higher than the pressure of the fluid discharged from the compressed fluid accumulator. 
   
   
       16 . A method for starting a compressor as defined in  claim 1 , comprising the steps of:
 in a start mode, opening a passage from the compressed fluid accumulator during the time needed for the aerostatic bearing of the compressor to float;   keeping the second control valve closed until the pressure of the pressurized outlet is higher than the pressure of the fluid discharged from the compressed fluid accumulator; and   recharging the compressed fluid accumulator from the fluid at the pressurized outlet.