Rotary machine system

Abstract

A rotary machine system includes: a rotary machine including a gas seal portion; a gas seal device connected to the rotary machine and that supplies a seal gas to the gas seal portion; and a connecting pipe that connects the gas seal portion and the gas seal device. The rotary machine includes a casing through which a working fluid flows; a rotatable rotary shaft; and the gas seal portion that seals the working fluid by the seal gas having a pressure higher than a pressure of the working fluid in the casing. The gas seal device includes: a seal gas supply pipe through which the seal gas delivered to the connecting pipe flows; a pressure regulating valve provided in the seal gas supply pipe and that adjusts the pressure of the seal gas supplied to the gas seal portion; and a control part.

What is claimed is: 
     
       1. A rotary machine system comprising:
 a rotary machine comprising a gas seal portion; 
 a gas seal device connected to the rotary machine and that supplies a seal gas to the gas seal portion; and 
 a connecting pipe that connects the gas seal portion and the gas seal device, wherein the rotary machine comprises:
 a casing through which a working fluid flows; 
 a rotatable rotary shaft that passes through an inside and an outside of the casing; and 
 the gas seal portion provided between the casing and the rotary shaft and that seals the working fluid by the seal gas having a pressure higher than a pressure of the working fluid in the casing, 
 
 the gas seal device comprises:
 a seal gas supply pipe through which the seal gas delivered to the connecting pipe flows; 
 a pressure regulating valve provided in the seal gas supply pipe and that adjusts the pressure of the seal gas supplied to the gas seal portion; and 
 a control part that controls the pressure regulating valve according to the pressure of the seal gas, and 
 
 the connecting pipe has a pipe diameter larger than a pipe diameter of the seal gas supply pipe. 
 
     
     
       2. The rotary machine system according to  claim 1 , further comprising a joint portion having an inner diameter gradually reduced from the connecting pipe side, wherein the joint portion is provided in at least one of a space between the connecting pipe and the seal gas supply pipe and a space between the connecting pipe and a port connection hole through which the connecting pipe is connected to the casing. 
     
     
       3. The rotary machine system according to  claim 1 , wherein the control part increases an opening degree of the pressure regulating valve when a change amount of the pressure of the seal gas supplied from the gas seal device to the gas seal portion is equal to or more than a predetermined threshold value. 
     
     
       4. The rotary machine system according to  claim 1 , wherein the pipe diameter of the connecting pipe is formed so that a pressure loss in the connecting pipe is equal to or less than a predetermined value which is set in advance.