Compressor system, subsea production system provided therewith, and compressor cleaning method

Abstract

A compressor system includes a compressor ( 50 ) that includes a casing, a rotation shaft supported in the casing and an impeller that rotates together with the rotation shaft and compresses a gas. The compressor system includes a compressed gas circulation unit ( 52 ) in which the gas compressed by the compressor ( 50 ) circulates, a hydrate anti freezing agent supply unit ( 53 ) configured to supply a hydrate anti freezing agent that prevents hydration of the gas to the compressed gas circulation unit ( 52 ), and an internal hydrate anti freezing agent supply unit ( 54 ) configured to supply part of the hydrate anti freezing agent to an internal flow path of the compressor ( 50 ).

1 . A compressor system comprising:
 a compressor including a casing, a rotation shaft supported in the casing, and an impeller that rotates together with the rotation shaft and compresses a gas;   a compressed gas circulation unit in which the gas compressed by the compressor circulates;   a hydrate anti freezing agent supply unit configured to supply a hydrate anti freezing agent that prevents hydration of the gas to the compressed gas circulation unit; and   an internal hydrate anti freezing agent supply unit configured to supply part of the hydrate anti freezing agent supplied from the hydrate anti freezing agent supply unit to an internal flow path formed of the impeller and the casing.   
     
     
         2 . The compressor system according to  claim 1 , comprising a control unit configured to perform supply control such that, when predetermined conditions are satisfied, the internal hydrate anti freezing agent supply unit starts supply of the hydrate anti freezing agent to the internal flow path. 
     
     
         3 . The compressor system according to  claim 2 , wherein the control unit includes a first reference determination unit configured to determine whether a difference between characteristic values of the gas on an inlet side of the compressor and an outlet side of the compressor satisfies a predetermined first reference; and
 a supply start instruction unit configured to send an instruction to the internal hydrate anti freezing agent supply unit to start supply of the hydrate anti freezing agent to the internal flow path when the first reference determination unit determines that the first reference is satisfied.   
     
     
         4 . The compressor system according to  claim 1 , comprising
 a heating unit configured to heat the hydrate anti freezing agent,   wherein the internal hydrate anti freezing agent supply unit supplies the hydrate anti freezing agent heated by the heating unit to the internal flow path.   
     
     
         5 . The compressor system according to  claim 3 , comprising
 a heating unit configured to heat the hydrate anti freezing agent,   wherein the control unit includes   a second reference determination unit configured to determine whether a difference between characteristic values of the gas on the inlet side of the compressor and the outlet side of the compressor satisfies a predetermined second reference after supply of the hydrate anti freezing agent to the internal flow path starts; and   a heat supply instruction unit configured to send an instruction to the internal hydrate anti freezing agent supply unit to supply the hydrate anti freezing agent heated by the heating unit to the internal flow path when the second reference determination unit determines that the second reference is satisfied.   
     
     
         6 . A subsea production system comprising:
 the compressor system according to  claim 1 ; and   a separator configured to separate a production fluid drawn from a production well into the gas and a liquid and supply the result to the compressor.   
     
     
         7 . A compressor cleaning method in which a compressor including a casing, a rotation shaft supported in the casing and an impeller that rotates together with the rotation shaft and compresses a gas is cleaned, the method comprising:
 a first reference determining process of determining whether a difference between characteristic values of the gas on an inlet side of the compressor and an outlet side of the compressor satisfies a predetermined first reference; and   a supply start process in which, when it is determined that the first reference is satisfied in the first reference determining process, supply of a hydrate anti freezing agent that prevents hydration of the gas compressed by the compressor to an internal flow path formed of the impeller and the casing starts.   
     
     
         8 . The compressor cleaning method according to  claim 7 , comprising
 a second reference determining process in which, after supply of the hydrate anti freezing agent to the internal flow path starts, it is determined whether a difference between characteristic values of the gas on an inlet side of the compressor and an outlet side of the compressor satisfies a predetermined second reference; and   a heat supply process in which, when it is determined that the second reference is satisfied in the second reference determining process, the heated hydrate anti freezing agent is supplied to the internal flow path.   
     
     
         9 . The compressor system according to  claim 2 , comprising
 a heating unit configured to heat the hydrate anti freezing agent,   wherein the internal hydrate anti freezing agent supply unit supplies the hydrate anti freezing agent heated by the heating unit to the internal flow path.   
     
     
         10 . The compressor system according to  claim 3 , comprising a heating unit configured to heat the hydrate anti freezing agent, wherein the internal hydrate anti freezing agent supply unit supplies the hydrate anti freezing agent heated by the heating unit to the internal flow path. 
     
     
         11 . A subsea production system comprising:
 the compressor system according to  claim 2 ; and   a separator configured to separate a production fluid drawn from a production well into the gas and a liquid and supply the result to the compressor.   
     
     
         12 . A subsea production system comprising:
 the compressor system according to  claim 3 ; and   a separator configured to separate a production fluid drawn from a production well into the gas and a liquid and supply the result to the compressor.   
     
     
         13 . A subsea production system comprising:
 the compressor system according to  claim 4 ; and   a separator configured to separate a production fluid drawn from a production well into the gas and a liquid and supply the result to the compressor.   
     
     
         14 . A subsea production system comprising:
 the compressor system according to  claim 5 ; and   a separator configured to separate a production fluid drawn from a production well into the gas and a liquid and supply the result to the compressor.