Cryogenic pump

Abstract

A piston pump suitable for pumping a fluid at very low temperature, for example hydrogen, is disclosed. The pump has a suction side and a compression side, the suction side comprising an inlet provided for the liquid and intended to connected a liquid supply reservoir external to the pump, a suction chamber for receiving the fluid and a first fluid degassing duct communicating with the suction chamber, the compression side comprising a pump cylinder carrying an assembly for compression and delivery of the liquid, said cylinder comprising a second chamber which communicates with the suction chamber and wherein the fluid at very low temperature circulates in order to cool the compression and delivery assembly.

1 . A piston pump suitable for pumping a fluid at very low temperature, for example hydrogen, said pump having a suction side and a compression side,
 the suction side comprising an inlet provided for the liquid and intended to connect a liquid supply reservoir external to the pump, a suction chamber for receiving the fluid and a first fluid degassing duct communicating with the suction chamber,   the compression side comprising a pump cylinder carrying an assembly for compression and delivery of the liquid, said cylinder comprising a second chamber which communicates with the suction chamber and wherein the fluid at very low temperature circulates in order to cool the compression and delivery assembly.   
     
     
         2 . The pump according to  claim 1 , wherein the cylinder comprises a first casing and an internal cylinder body carrying the compression and delivery assembly, said first casing being attached to the cylinder body, said cylinder body having a recessed shape allowing the circulation of fluid in the second chamber. 
     
     
         3 . The pump according to  claim 1 , further comprising a second degassing duct communicating with the second chamber and configured to allow degassing of the fluid circulating in the second chamber. 
     
     
         4 . The pump according to  claim 1 , wherein the compression and delivery assembly comprises:
 a pump liner and a cylinder head that are integral and coaxial,   a piston that is axially movable in the liner forming a fluid compression chamber with the cylinder head, said cylinder head connecting the liner to the suction chamber, and   a delivery opening arranged in the liner.   
     
     
         5 . The pump according to  claim 4 , wherein the cylinder head comprises a pre-compression chamber communicating with the suction chamber. 
     
     
         6 . The pump according to  claim 4 , wherein the cylinder head comprises an exhaust port configured to allow the pressure in the compression chamber to be adjusted. 
     
     
         7 . The pump according to  claim 2 , wherein the cylinder comprises a second casing that is external with respect to the first casing and forming with the latter a space intended to be evacuated. 
     
     
         8 . The pump according to  claim 7 , wherein an insulating material is arranged between the first casing and the second casing. 
     
     
         9 . The pump according to  claim 8 , wherein the insulating material is multi-layer insulation. 
     
     
         10 . The pump according to  claim 9 , wherein the multi-layer insulation comprises alternating layers of aluminum and layers of fiberglass. 
     
     
         11 . A piston pump suitable for pumping a liquid at a very low temperature, comprising:
 a suction side, comprising:
 an inlet provided for the liquid and intended to connect a liquid supply reservoir to the pump; 
 a suction chamber for receiving the liquid; and 
 a liquid degassing duct in communication with the suction chamber; and 
   a compression side, comprising:
 a pump cylinder carrying an assembly for compression and delivery of the liquid, said pump cylinder comprising a second chamber which communicates with the suction chamber, wherein the liquid at very low temperature circulates in order to cool the compression and delivery assembly.