Multi-stage compressor system for generating a compressed gas

Abstract

A compressor system for generating a compressed gas having at least one main compressor to which pre-compressed gas is fed using at least one pre-compressor, wherein the at least one main compressor is driven, as is also the at least one pre-compressor, by a common drive motor or separate drives, wherein at least one pre-compressor is assigned a hydrodynamic fluid coupling for changing the drive speed of the pre-compressor.

1 . A compressor system for generating a compressed gas having at least one main compressor ( 30 ) to which pre-compressed gas is to be fed using at least one pre-compressor ( 20 ),
 wherein   the at least one main compressor ( 30 ) is driven, as is also the at least one pre-compressor ( 20 ), by a common drive motor ( 40 ) or separate drives,   wherein at least one pre-compressor ( 20 ) is assigned a hydrodynamic fluid coupling ( 55 ) for changing the drive speed of the pre-compressor ( 20 ).   
     
     
         2 . The compressor system as claimed in  claim 1 ,
 wherein   both the drive speed of the fluid coupling ( 55 ) and the drive speed of the pre-compressor ( 20 ) are adapted by at least one suitable transmission ( 56 ).   
     
     
         3 . The compressor system as claimed in  claim 1 ,
 wherein   the pre-compressor ( 20 ) is composed of at least one turbo compressor which is embodied with a radial design.   
     
     
         4 . The compressor system as claimed in  claim 1 ,
 wherein   at least two turbo compressors are arranged as pre-compressors ( 20 ) with parallel intake in order to increase the volume flow, said turbo compressors being driven by one or more fluid couplings ( 55 ).   
     
     
         5 . The compressor system as claimed in  claim 1 ,
 wherein   at least two turbo compressors are arranged as pre-compressors ( 20 ) with serial intake in order to increase the admission pressure, said turbo compressors being driven by one or more fluid couplings ( 55 ).   
     
     
         6 . The compressor system as claimed in  claim 5 ,
 wherein   at least one intermediate cooler is arranged between the at least two turbo compressors in order to improve the efficiency.   
     
     
         7 . The compressor system as claimed in  claim 1 ,
 wherein   in order to regulate the fluid coupling ( 55 ), regulating elements for the infinitely variable adaptation of the rotational speed of the fluid coupling ( 55 ) are provided in the inflow and/or in the outflow of the operating fluid of the fluid coupling ( 55 ).   
     
     
         8 . The compressor system as claimed in  claim 1 ,
 wherein   the mechanical drive of the pre-compressor ( 20 ) is integrated together with the fluid coupling ( 55 ) into a housing of the main compressor ( 30 ).   
     
     
         9 . The compressor system as claimed in  claim 1 ,
 wherein   an intermediate cooler ( 25 ) is arranged between the pre-compressor ( 20 ) and the main compressor ( 30 ) in order to improve the efficiency.   
     
     
         10 . The compressor system as claimed in  claim 1 ,
 wherein   the at least one main compressor ( 30 ) is a fluid-injected compressor,   wherein the fluid of the main compressor ( 30 ) is also to be fed as working medium to the fluid coupling ( 55 ) of the pre-compressor ( 20 ).   
     
     
         11 . The compressor system as claimed in  claim 1 ,
 wherein   the drive of the fluid coupling ( 55 ) is provided directly or by way of a transmission from the main compressor ( 30 ) or from the drive motor ( 40 ).   
     
     
         12 . The compressor system as claimed in  claim 1 ,
 wherein   the compressor system comprises one or more screw compressors with or without fluid injection and at least one radial turbo compressor for pre-compressing the gas.   
     
     
         13 . The compressor system as claimed in  claim 1 ,
 wherein   the fluid of the lubrication circuit and/or cooling circuit for the bearings, the drive transmission and/or the housing cooling of the main compressor ( 30 ) is at least partially also the working medium of the fluid coupling ( 55 ) of the pre-compressor ( 20 ).   
     
     
         14 . The compressor system as claimed in  claim 1 ,
 wherein   the pre-compressor ( 20 ), the fluid coupling ( 55 ) and all the transmission ratios ( 56 ) which are arranged for the purpose of reaching the desired rotational speed are integrated into a screw compressor.   
     
     
         15 . The compressor system as claimed in  claim 2 ,
 wherein   the transmission ratios are embodied in a shiftable fashion in order to regulate the rotational speed.   
     
     
         16 . The compressor system as claimed in  claim 12 ,
 wherein   an optimum internal volume ratio of the screw compressor is set as a function of the actual final pressure and of the actual admission pressure by mechanical adjustment devices and/or valves.   
     
     
         17 . A method for regulating a compressor system as claimed in  claim 1 ,
 wherein   in the case of a drive ( 40 ) of the compressor system by an electric motor, the winding temperature thereof and/or the power drain and/or the current voltage are detected as parameters of the utilization factor of the electric motor and used as a regulated variable, in order to regulate, through changes in the operating parameters of the fluid coupling ( 55 ), the admission pressure which is generated by the pre-compressor ( 20 ) in such a way that the electric motor is loaded or relieved of loading to a greater degree.   
     
     
         18 . The method for regulating a compressor system as claimed in  claim 1 ,
 wherein   in the case of a drive ( 40 ) of the compressor system by an internal combustion engine, the output gas temperature and/or coolant water temperature and/or actual torque thereof are detected as a function of the fuel injection quantity and the rotational speed as parameters of the utilization factor of the internal combustion engine and used as a regulated variable, in order to regulate, through changes in the operating parameters of the fluid coupling ( 55 ), the admission pressure generated by the pre-compressor ( 20 ) in such a way that the internal combustion engine is loaded or relieved of loading to a greater degree.   
     
     
         19 . The compressor system as claimed in  claim 11 ,
 wherein   the transmission ratios are embodied in a shiftable fashion in order to regulate the rotational speed.   
     
     
         20 . The compressor system as claimed in  claim 14 ,
 wherein   an optimum internal volume ratio of the screw compressor is set as a function of the actual final pressure and of the actual admission pressure by mechanical adjustment devices and/or valves.