Compressor and hydrogen station

Abstract

A compression stage includes a cylinder, a piston, a first piston ring group, and a second piston ring group. The cylinder includes a first cooling channel through which a cooling fluid for absorbing heat generated between the cylinder and the first piston ring group flows, a second cooling channel through which a cooling fluid for absorbing heat generated between the cylinder and the second piston ring group flows, and an intermediate part disposed between the first cooling channel and the second cooling channel. A communication channel is connected to the intermediate part and a connection pipe, and guides a hydrogen gas leaking from a compression chamber through the first piston ring group to the intermediate part, to the outside of the cylinder.

1 . A compressor for compressing a hydrogen gas, the compressor comprising:
 a plurality of compression stages; and   a drive mechanism configured to drive the plurality of compression stages,   wherein at least one compression stage out of the plurality of compression stages includes:   a cylinder;   a piston inserted into the cylinder;   a first piston ring group provided on the piston; and   a second piston ring group disposed closer to the drive mechanism than the first piston ring group,   the cylinder includes:   a first cooling channel through which a cooling fluid for absorbing heat generated between the cylinder and the first piston ring group flows;   a second cooling channel through which a cooling fluid for absorbing heat generated between the cylinder and the second piston ring group flows; and   a through hole provided in an intermediate part between the first cooling channel and the second cooling channel and penetrating an inner surface and an outer surface of the cylinder,   the compressor further includes a communication channel communicating with a suction channel connected to the through hole and to the at least one compression stage, or a lower-pressure channel with lower pressure than the suction channel, the communication channel guiding the hydrogen gas leaking from a tip of the piston through the first piston ring group into the intermediate part to outside of the cylinder.   
     
     
         2 . The compressor according to  claim 1 , wherein
 the at least one compression stage and the preceding compression stage have a tandem structure,   the preceding compression stage includes:   a low pressure side cylinder connected to the cylinder on a drive mechanism side;   a low pressure side piston inserted into the low pressure side cylinder, connected to the piston, and having a diameter larger than a diameter of the piston; and   a third piston ring group provided on the low pressure side piston.   
     
     
         3 . The compressor according to  claim 1 , wherein
 the at least one compression stage includes   a distance piece connected to the cylinder and for collecting the hydrogen gas that has passed through the first piston ring group and the second piston ring group.   
     
     
         4 . The compressor according to  claim 1 , wherein
 the suction channel includes a gas cooling unit for cooling the hydrogen gas flowing through the suction channel, and   the communication channel is connected to a portion upstream of the gas cooling unit in the suction channel.   
     
     
         5 . The compressor according to  claim 1 , wherein
 the communication channel is connected to the suction channel, and   a check valve is disposed on the communication channel.   
     
     
         6 . The compressor according to  claim 1 , wherein
 the plurality of compression stages includes another preceding compression stage of the at least one compression stage,   the low-pressure channel is a channel through which the hydrogen gas sucked into the another preceding compression stage flows,   the communication channel is connected to the low-pressure channel, and a pressure reducing valve is disposed on the communication channel.   
     
     
         7 . The compressor according to  claim 1 , wherein
 the intermediate part includes a communication passage that allows the first cooling channel to communicate with the second cooling channel at a different position in a circumferential direction from the through hole.   
     
     
         8 . The compressor according to  claim 1 , wherein
 an inner diameter of the communication channel is 10% or more of an inner diameter of the cylinder, and volume of the communication channel is larger than volume of a micro gap in a section corresponding to the first piston ring group out of volume of the micro gap between the piston and the cylinder.   
     
     
         9 . A hydrogen station comprising:
 the compressor according to  claim 1 ;   an accumulator for storing the hydrogen gas discharged from the compressor; and   a dispenser for receiving supply of the hydrogen gas from the accumulator.