Cryogenic pump system

Abstract

A cryogenic pump system for lifting a cryogenic fluid stored in a cryogenic tank includes a first pump assembly and a second pump assembly. The first pump assembly includes a boost pump that is configured to be disposed within the cryogenic tank and pump the cryogenic fluid received from the cryogenic tank. The second pump assembly is configured to receive the cryogenic fluid from the first pump assembly. The second pump assembly includes a housing, a stator, a reciprocating member, and at least one piston. The housing is adapted to store the cryogenic fluid received from the boost pump. The stator is adapted to produce a magnetic field. The reciprocating member is disposed within the housing and is configured to move based on the magnetic field. The piston is configured to be moved by the reciprocating member to direct the cryogenic fluid from the housing out of the cryogenic tank.

What is claimed is: 
     
         1 . A cryogenic pump system for lifting a cryogenic fluid stored in a cryogenic tank, the cryogenic pump system comprising:
 a first pump assembly including a boost pump that is configured to be disposed within the cryogenic tank and pump the cryogenic fluid received from the cryogenic tank; and   a second pump assembly configured to receive the cryogenic fluid from the first pump assembly, the second pump assembly including:
 a housing to store the cryogenic fluid received from the boost pump; 
 a stator to produce a magnetic field; and 
 a reciprocating member disposed within the housing and configured to move based on the magnetic field produced by the stator; and 
 at least one piston configured to be moved by the reciprocating member to direct the cryogenic fluid from the housing out of the cryogenic tank. 
   
     
     
         2 . The cryogenic pump system of  claim 1 , wherein the boost pump is driven by a motor, the motor being cooled by a discharge of the cryogenic fluid from the boost pump. 
     
     
         3 . The cryogenic pump system of  claim 1 , wherein the first pump assembly is configured to be submerged within the cryogenic fluid. 
     
     
         4 . The cryogenic pump system of  claim 1 , wherein the first pump assembly is a low pressure pump assembly and the second pump assembly is a high pressure pump assembly. 
     
     
         5 . The cryogenic pump system of  claim 1 , wherein the second pump assembly is configured to be disposed within the cryogenic tank. 
     
     
         6 . The cryogenic pump system of  claim 1 , further including a support structure to mount the first pump assembly and the second pump assembly within the cryogenic tank. 
     
     
         7 . The cryogenic pump system of  claim 6 , wherein the support structure is configured to stack the first pump assembly and the second pump assembly within the cryogenic tank such that the second pump assembly is positioned at a higher elevation than the first pump assembly. 
     
     
         8 . The cryogenic pump system of  claim 1 , wherein the second pump assembly is configured to be cooled by the cryogenic fluid stored within the housing. 
     
     
         9 . The cryogenic pump system of  claim 1 , wherein the boost pump is configured to provide the cryogenic fluid to the housing at a pressure to prevent a flash boiling of the cryogenic fluid in the housing. 
     
     
         10 . The cryogenic pump system of  claim 1 , wherein the cryogenic fluid is liquefied natural gas. 
     
     
         11 . A cryogenic fuel system for an engine, the cryogenic fuel system comprising:
 a cryogenic tank to store a cryogenic fuel;   a first pump assembly including a boost pump that is configured to be disposed within the cryogenic tank and pump the cryogenic fluid received from the cryogenic tank; and   a second pump assembly configured to receive the cryogenic fluid from the first pump assembly, the second pump assembly including:
 a housing to store the cryogenic fluid received from the boost pump; 
 a stator to produce a magnetic field; and 
 a reciprocating member disposed within the housing and configured to move based on the magnetic field produced by the stator; and 
 at least one piston configured to be moved by the reciprocating member to direct the cryogenic fluid from the housing out of the cryogenic tank. 
   
     
     
         12 . The cryogenic fuel system of  claim 11 , wherein the boost pump is driven by a motor, the motor being cooled by a discharge of the cryogenic fuel from the boost pump. 
     
     
         13 . The cryogenic fuel system of  claim 11 , wherein the first pump assembly is configured to be submerged within the cryogenic fuel. 
     
     
         14 . The cryogenic fuel system of  claim 11 , wherein the first pump assembly is a low pressure pump assembly and the second pump assembly is a high pressure pump assembly. 
     
     
         15 . The cryogenic fuel system of  claim 11 , wherein the second pump assembly is configured to be disposed within the cryogenic tank. 
     
     
         16 . The cryogenic fuel system of  claim 11 , further including a support structure to mount the first pump assembly and the second pump assembly within the cryogenic tank. 
     
     
         17 . The cryogenic fuel system of  claim 16 , wherein the support structure is configured to stack the first pump assembly and the second pump assembly within the cryogenic tank such that the second pump assembly is positioned at a higher elevation than the first pump assembly. 
     
     
         18 . The cryogenic fuel system of  claim 11 , wherein the second pump assembly is configured to be cooled by the cryogenic fluid stored within the housing. 
     
     
         19 . The cryogenic fuel system of  claim 11 , wherein the boost pump is configured to provide the cryogenic fuel to the housing at a pressure to prevent a flash boiling of the cryogenic fuel in the housing. 
     
     
         20 . The cryogenic fuel system of  claim 11 , wherein the cryogenic fuel is liquefied natural gas.