Internally-cooled centrifugal compressor with cooling jacket formed in the diaphragm

Abstract

An internally-cooled centrifugal compressor having a shaped casing and a diaphragm disposed within the shaped casing having a gas side and a coolant side so that heat from a gas flowing through the gas side is extracted via the coolant side. An impeller disposed within the diaphragm has a stage inlet on one side and a stage outlet for delivering a pressurized gas to a downstream connection. The coolant side of the diaphragm includes at least one passageway for directing a coolant in a substantially counter-flow direction from the flow of gas through the gas side.

We claim: 
     
         1 . An internally-cooled centrifugal compressor, comprising:
 a shaped casing having a stage inlet for an upstream gas connection and a stage outlet for a downstream gas connection; and   a diaphragm arranged within said shaped casing and having a gas side and a coolant side so that heat from a gas flowing through the gas side is extracted via said coolant side, wherein the coolant side includes a cooling agent flow path for directing a cooling agent in a substantially counter-flow direction from a flow of the gas through the gas side.   
     
     
         2 . The compressor of  claim 1 , further comprising an impeller disposed within said diaphragm, the impeller having a first side fluidly coupled to the stage inlet for receiving the gas from the upstream gas connection and delivering the gas to said impeller, and a second side fluidly coupled to said stage outlet for delivering a pressurized gas to the downstream gas connection through said stage outlet. 
     
     
         3 . The compressor of  claim 1 , wherein the gas side of the diaphragm comprises:
 a diffuser having a plurality of diffuser vanes arranged therein, the diffuser being proximally located near the coolant side of the diaphragm so that heat in the gas can be extracted by the cooling agent flowing through said coolant side; and   a return channel fluidly coupled to the diffuser and having a plurality of return channel vanes arranged therein, the return channel being configured to deliver the pressurized gas to the stage outlet of the diaphragm.   
     
     
         4 . The compressor of  claim 3 , wherein the coolant side of the diaphragm comprises:
 a first chamber from which the cooling agent originates;   a center bulb defined by the diaphragm and interposed between the diffuser and the return channel, the center bulb being in fluid communication with the first chamber via one or more return conduits defined within the plurality of return channel vanes, wherein the cooling agent flows from the first chamber into the center bulb; and   a second chamber in fluid communication with the center bulb via one or more diffuser conduits defined within the plurality of diffuser vanes, wherein the cooling agent flows from the center bulb into the second chamber.   
     
     
         5 . The compressor of  claim 4 , wherein the return conduits and/or the diffuser conduits are coarsely threaded. 
     
     
         6 . The compressor of  claim 4 , wherein the first chamber and/or the second chamber of the coolant side is formed of a roughened-walled structure. 
     
     
         7 . The compressor of  claim 4 , wherein said gas side of said diaphragm is formed of a smooth-walled structure. 
     
     
         8 . The compressor of  claim 4 , wherein the first chamber and/or the second chamber have a plurality of structural vanes arranged therein to generate turbulence of the cooling agent. 
     
     
         9 . The compressor of  claim 1 , wherein the cooling agent is a liquid coolant. 
     
     
         10 . The compressor of  claim 1 , wherein the cooling agent is a gas coolant. 
     
     
         11 . An internally-cooled centrifugal compressor diaphragm, comprising:
 a rotatable impeller centrally-disposed within the diaphragm;   a diffuser fluidly coupled to an outlet of the impeller and having a plurality of diffuser vanes arranged therein, each diffuser vane having at least one diffuser conduit defined therein;   a return channel fluidly coupled to the diffuser and having a plurality of return channel vanes arranged therein, each return channel vane having at least one return conduit defined therein;   a cooling jacket proximally-located about the diffuser and the return channel, the cooling jacket having a first chamber and a second chamber; and   a center bulb defined within the diaphragm and interposed between the diffuser and the return channel, the center bulb being in fluid communication with the first chamber via the at least one return conduit and in fluid communication with the second chamber via the at least one diffuser conduit.   
     
     
         12 . The diaphragm of  claim 11 , wherein the return conduits and/or the diffuser conduits are coarsely threaded. 
     
     
         13 . The diaphragm of  claim 11 , wherein the first chamber and/or the second chamber have a plurality of structural vanes arranged therein. 
     
     
         14 . The diaphragm of  claim 13 , wherein the structural vanes provide structural support for the diaphragm. 
     
     
         15 . The diaphragm of  claim 13 , wherein the structural vanes introduce turbulence to a cooling agent flowing therein. 
     
     
         16 . The diaphragm of  claim 11 , wherein the diffuser and the return channel are smooth-walled structures. 
     
     
         17 . A method of cooling a working fluid in a centrifugal compressor, comprising:
 circulating the working fluid through a diffuser having a plurality of diffuser vanes arranged therein, each diffuser vane having at least one diffuser conduit defined therein;   receiving the working fluid in a return channel fluidly coupled to the diffuser and having a plurality of return channel vanes arranged therein, each return channel vane having at least one return conduit defined therein;   circulating a cooling agent from a first chamber into a center bulb interposed between the diffuser and the return channel, the first chamber being located adjacent the return channel and in fluid communication with the center bulb via the at least one return conduit; and   circulating the cooling agent from the center bulb to a second chamber, the second chamber being located adjacent the diffuser and in fluid communication with the center bulb via the at least one diffuser conduit, whereby as the cooling agent is circulated it removes heat from the working fluid.   
     
     
         18 . The method of  claim 17 , further comprising generating a turbulent cooling agent by circulating the cooling agent within the first and second chambers having structural vanes arranged therein. 
     
     
         19 . The method of  claim 17 , further comprising generating a turbulent cooling agent by circulating the cooling agent through a coarsely threaded return conduit and/or a coarsely threaded diffuser conduit. 
     
     
         20 . The method of  claim 17 , further comprising circulating the cooling agent through the first chamber, the center bulb, and the second chamber in a substantially counter-flow direction with respect to a flow of the working fluid.