Hydrogen generation assemblies

Abstract

Hydrogen generation assemblies and their components are disclosed. In some embodiments, the assemblies may include a pump controller configured to select a flowrate from a plurality of flowrates based on detected pressure, and to operate the pump at the selected flowrate. In some embodiments, the assemblies may include a purge valve assembly configured to allow at least one pressurized gas to flow through a purge conduit from a pressurized gas assembly to a fuel processing assembly when power to the fuel processing assembly is interrupted. In some embodiments, the assemblies may include a damper controller configured to move a damper between fully open and closed positions based, at least in part, on detected temperature in a hydrogen-producing region. In some embodiments, the assemblies may include a reformer controller configured to operate a fuel processing assembly between run and standby modes based, at least in part, on detected pressure.

What is claimed is: 
     
         1 . A hydrogen generation assembly, comprising:
 a fuel processing assembly configured to receive a feed stream and produce a product hydrogen stream from the feed stream;   a feed assembly configured to deliver the feed stream to the fuel processing assembly, the feed assembly including:
 a feed tank configured to contain feedstock for the feed stream, 
 a feed conduit fluidly connecting the feed tank and the fuel processing assembly, and 
 a pump configured to deliver the feed stream at a plurality of flowrates to the fuel processing assembly via the feed conduit; and 
   a control system, including:
 a feed sensor assembly configured to detect pressure in the feed conduit downstream from the pump, and 
 a pump controller configured to select a flowrate from the plurality of flowrates based on the detected pressure in the feed conduit, and to operate the pump at the selected flowrate. 
   
     
     
         2 . The assembly of  claim 1 , wherein the pump controller is further configured to select the flowrate based solely on the detected pressure in the feed conduit. 
     
     
         3 . The assembly of  claim 1 , wherein the feed sensor assembly is further configured to generate a signal based on the detected pressure in the feed conduit, the pump controller being further configured to condition the signal received from the sensor assembly and to select the flowrate based on the conditioned signal. 
     
     
         4 . The assembly of  claim 3 , wherein the pump controller is further configured to invert the signal received from the feed sensor assembly and to select the flowrate based on the inverted signal. 
     
     
         5 . The assembly of  claim 1 , further comprising a purge assembly, including:
 a pressurized gas assembly fluidly connected to the feed conduit and configured to receive at least one container of pressurized gas that is configured to purge the fuel processing assembly; and   a purge valve assembly configured to allow the at least one pressurized gas to flow through the feed conduit from the pressurized gas assembly to the fuel processing assembly when power to the fuel processing assembly is interrupted.   
     
     
         6 . The assembly of  claim 1 , further comprising an enclosure having an exhaust port, the fuel processing assembly including a hydrogen-producing region contained within the enclosure and configured to provide, via a steam reforming reaction, the product hydrogen stream from the feed stream, wherein the control system further includes a reformer sensor assembly configured to detect temperature in the hydrogen-producing region. 
     
     
         7 . The assembly of  claim 6 , further comprising:
 a heating assembly configured to receive at least one air stream and at least one fuel stream and to combust the at least one fuel stream within a combustion region contained within the enclosure producing a heated exhaust stream for heating at least the hydrogen-producing region to at least a minimum hydrogen-producing temperature; and   a damper moveably connected to the exhaust port and configured to move among a plurality of positions including a fully open position in which the damper allows the heated exhaust stream to flow through the exhaust port, a closed position in which the damper prevents the heated exhaust stream from flowing through the exhaust port, and a plurality of intermediate open positions between the fully open and closed positions, and wherein the control system further includes a damper controller configured to move the damper between the fully open and closed positions based, at least in part, on the detected temperature in the hydrogen-producing region.   
     
     
         8 . The assembly of  claim 1 , wherein the fuel processing assembly is further configured to be operable among a plurality of modes, including a run mode in which the fuel processing assembly produces the product hydrogen stream from the feed stream, and a standby mode in which the fuel processing assembly does not produce the product hydrogen stream from the feed stream. 
     
     
         9 . The assembly of  claim 8 , further comprising a buffer tank configured to contain the product hydrogen stream, and a product conduit fluidly connecting the fuel processing assembly and the buffer tank, wherein the control system further includes:
 a product sensor assembly configured to detect pressure in the buffer tank, and   a control assembly configured to operate the fuel processing assembly between the run and standby modes based, at least in part, on the detected pressure in the buffer tank.   
     
     
         10 . A hydrogen generation assembly, comprising:
 a fuel processing assembly configured to receive a feed stream and produce a product hydrogen stream from the feed stream;   a pressurized gas assembly configured to receive at least one container of pressurized gas that is configured to purge the fuel processing assembly;   a purge conduit configured to fluidly connect the pressurized gas assembly and the fuel processing assembly; and   a purge valve assembly configured to allow the at least one pressurized gas to flow through the purge conduit from the pressurized gas assembly to the fuel processing assembly when power to the fuel processing assembly is interrupted.   
     
     
         11 . The assembly of  claim 10 , wherein the purge valve assembly includes a purge valve that moves between a closed position in which the at least one pressurized gas does not flow through the purge conduit from the pressurized gas assembly, and an open position in which the at least one pressurized gas is allowed to flow through the purge conduit from the pressurized gas assembly. 
     
     
         12 . The assembly of  claim 11 , wherein the purge valve is in the closed position when there is power to the fuel processing assembly, and wherein the purge valve automatically moves to the open position when power to the fuel processing assembly is interrupted. 
     
     
         13 . The assembly of  claim 11 , wherein the purge valve assembly further includes a purge solenoid configured to move the purge valve between the open and closed positions, the fuel processing assembly including a control system configured to send a control signal to the purge solenoid, and wherein the purge solenoid is configured to move the purge valve to the closed position when the purge solenoid receives the control signal, and to automatically move the purge valve to the open position when the purge solenoid does not receive the control signal. 
     
     
         14 . The assembly of  claim 10 , wherein at least a portion of the fuel processing assembly and at least a portion of the purge assembly are contained within an enclosure. 
     
     
         15 . A steam reforming hydrogen generation assembly configured to receive at least one feed stream and generate a reformate stream containing hydrogen gas as a majority component and other gases, comprising:
 an enclosure having an exhaust port;   a hydrogen-producing region contained within the enclosure and configured to produce, via a steam reforming reaction, the reformate stream from the at least one feed stream;   a reformer sensor assembly configured to detect temperature in the hydrogen-producing region;   a heating assembly configured to receive at least one air stream and at least one fuel stream and to combust the at least one fuel stream within a combustion region contained within the enclosure producing a heated exhaust stream for heating at least the hydrogen-producing region to at least a minimum hydrogen-producing temperature; and   a damper moveably connected to the exhaust port and configured to move among a plurality of positions including a fully open position in which the damper allows the heated exhaust stream to flow through the exhaust port, a closed position in which the damper prevents the heated exhaust stream from flowing through the exhaust port, and a plurality of intermediate open positions between the fully open and closed positions, and   a damper controller configured to move the damper between the fully open and closed positions based, at least in part, on the detected temperature in the hydrogen-producing region.   
     
     
         16 . The assembly of  claim 15 , further comprising a purification region contained within the enclosure and including a hydrogen-selective membrane, the purification region being configured to produce a permeate stream comprised of the portion of the reformate stream that passes through the hydrogen-selective membrane, and a byproduct stream comprised of the portion of the reformate stream that does not pass through the membrane, wherein the reformer sensor assembly is further configured to detect temperature in the purification region and the damper controller is configured to move the damper between the fully open and closed positions based, at least in part, on the detected temperature in at least one of the hydrogen-producing region and the purification region. 
     
     
         17 . The assembly of  claim 15 , wherein the damper controller is configured to move the damper toward the closed position when the detected temperature is above a predetermined maximum temperature. 
     
     
         18 . The assembly of  claim 15 , wherein the damper controller is configured to move the damper toward the fully open position when the detected temperature is below a predetermined minimum temperature. 
     
     
         19 . The assembly of  claim 15 , further comprising:
 a purge gas assembly configured to receive at least one container of pressurized gas that is configured to purge the hydrogen-producing region;   a purge conduit configured to fluidly connect the pressurized gas assembly and the hydrogen-producing region; and   a purge valve assembly configured to allow the at least one pressurized gas to flow through the purge conduit from the pressurized gas assembly to the hydrogen-producing region when power to the hydrogen-producing region is interrupted.   
     
     
         20 . The assembly of  claim 19 , further comprising a purification region contained within the enclosure and fluidly connected to the hydrogen-producing region, the purification region including a hydrogen-selective membrane, the at least one container of pressurized gas being configured to purge the hydrogen-selective membrane, and the purge valve assembly being configured to allow the at least one pressurized gas to flow through the purge conduit from the pressurized gas assembly to the hydrogen-selective membrane when power to the hydrogen-producing region is interrupted. 
     
     
         21 . The assembly of  claim 15 , wherein the hydrogen-producing region is configured to be operable between a plurality of modes, including a run mode in which the hydrogen-producing region produces the reformate stream from the at least one feed stream, and a standby mode in which the hydrogen-producing region does not produce the reformate stream from the at least one feed stream, the assembly further comprising:
 a buffer tank configured to contain the reformate stream;   a product conduit fluidly connecting the hydrogen-producing region and the buffer tank;   a buffer tank sensor assembly configured to detect pressure in the buffer tank; and   a reformer controller configured to operate the hydrogen-producing region between the run and standby modes based, at least in part, on the detected pressure in the buffer tank.   
     
     
         22 . A hydrogen generation assembly, comprising:
 a fuel processing assembly configured to receive a feed stream and to be operable among a plurality of modes, including a run mode in which the fuel processing assembly produces a product hydrogen stream from the feed stream, and a standby mode in which the fuel processing assembly does not produce the product hydrogen stream from the feed stream;   a buffer tank configured to contain the product hydrogen stream;   a product conduit fluidly connecting the fuel processing assembly and the buffer tank;   a tank sensor assembly configured to detect pressure in the buffer tank; and   a control assembly configured to operate the fuel processing assembly between the run and standby modes based, at least in part, on the detected pressure in the buffer tank.   
     
     
         23 . The assembly of  claim 22 , wherein the control assembly is configured to operate the fuel processing assembly in the standby mode when the detected pressure in the buffer tank is above a predetermined maximum pressure. 
     
     
         24 . The assembly of  claim 22 , wherein the control assembly is configured to operate the fuel processing assembly in the run mode when the detected pressure in the buffer tank is below a predetermined minimum pressure. 
     
     
         25 . The assembly of  claim 22 , further comprising a product valve assembly configured to manage flow in the product conduit, wherein the control assembly is configured to direct the product valve assembly to vent the product hydrogen stream from the fuel processing assembly when the fuel processing assembly is in the standby mode. 
     
     
         26 . The assembly of  claim 25 , wherein the product valve assembly includes at least one valve that is configured to operate between a flow position in which the product hydrogen stream from the fuel processing assembly flows through the product conduit and into the buffer tank, and a vent position in which the product hydrogen stream from the fuel processing assembly is vented prior to the buffer tank. 
     
     
         27 . The assembly of  claim 26 , wherein the control assembly is further configured to move the at least one valve to the flow position when the fuel processing assembly is in the run mode. 
     
     
         28 . The assembly of  claim 26 , wherein the control assembly is further configured to move the at least one valve to the vent position when the fuel processing assembly is in the standby mode. 
     
     
         29 . The assembly of  claim 26 , wherein the at least one valve is a three-way valve. 
     
     
         30 . The assembly of  claim 26 , wherein the at least one valve includes a first valve configured to control flow of the product hydrogen stream between the fuel processing assembly and the buffer tank, and a second valve configured to vent the product hydrogen stream from the fuel processing assembly. 
     
     
         31 . The assembly of  claim 30 , wherein the first valve is configured to move between a first open position in which the product hydrogen stream flows between the fuel processing assembly and the buffer tank, and a first closed position in which the product hydrogen stream does not flow between the fuel processing assembly and the buffer tank, wherein the second valve is configured to move between a second open position in which the product hydrogen stream is vented, and a second closed position in which the product hydrogen stream is not vented. 
     
     
         32 . The assembly of  claim 31 , wherein the control assembly is further configured to move the first valve to the first open position and the second valve in the second closed position when the fuel processing assembly is in the run mode. 
     
     
         33 . The assembly of  claim 32 , wherein the control assembly is further configured to move the first valve to the first closed position and the second valve in the second open position when the fuel processing assembly is in the standby mode. 
     
     
         34 . The assembly of  claim 22 , further comprising:
 a purge gas assembly configured to receive at least one container of pressurized gas that is configured to purge the fuel processing assembly;   a purge conduit configured to fluidly connect the pressurized gas assembly to the fuel processing assembly; and   a purge valve assembly configured to allow the at least one pressurized gas to flow through the purge conduit from the pressurized gas assembly to the fuel processing assembly when the fuel processing assembly is in the standby mode.   
     
     
         35 . The assembly of  claim 22 , further comprising:
 a purge gas assembly configured to receive at least one container of pressurized gas that is configured to purge the fuel processing assembly;   a purge conduit configured to fluidly connect the pressurized gas assembly to the fuel processing assembly; and   a purge valve assembly configured to allow the at least one pressurized gas to flow through the purge conduit from the pressurized gas assembly to the fuel processing assembly when power to the fuel processing assembly is interrupted.