What is claimed is:
1. A power system that comprises fuel cells and a fuel gas generation system for generating a hydrogen-rich fuel gas to be supplied to the fuel cells, and outputs electric power,
the fuel gas generation system comprising:
a chemical reaction module that generates a hydrogen-containing gaseous mixture from a predetermined material through a chemical process; and
a hydrogen separation module that separates hydrogen from the gaseous mixture,
the power system further comprising:
a hydrogen supply line that supplies the separated hydrogen to the fuel cells;
a stop signal input module that receives a stop signal for stopping the supply of hydrogen to the fuel cells;
a purge gas supply module that supplies specified purge gas for removal of hydrogen from the hydrogen separation module; and
a stop control module that selects a hydrogen purge mode that activates and controls the purge gas supply module to remove hydrogen from the hydrogen separation module or a hydrogen no-purge mode that stops the purge gas supply module as a stop control mode, executes stop control in the stop control mode to stop the supply of hydrogen to the fuel cells.
2. The power system in accordance with claim 1, the power system further comprising:
a parameter input module that inputs a predetermined parameter representing a working state of at least one of the power system and a system with the power system mounted thereon,
wherein the stop control module selects either of the hydrogen purge mode and the hydrogen no-purge mode as the stop control mode, based on the input parameter, and executes the stop control in the selected stop control mode.
3. The power system in accordance with claim 1, wherein the stop control module changes over the stop control mode to the hydrogen purge mode, after execution of the stop control in the hydrogen no-purge mode.
4. The power system in accordance with claim 3, the power system further comprising:
a parameter input module that inputs a predetermined parameter representing a working state of at least one of the power system and a system with the power system mounted thereon,
wherein the stop control module switches over the stop control mode from the hydrogen no-purge mode to the hydrogen purge mode, when the input parameter fulfils a preset condition.
5. The power system in accordance with claim 4, the power system further comprising:
a temperature measurement module that measures temperature at a preset position in the power system,
wherein the predetermined parameter includes a parameter representing the observed temperature, and
the stop control module switches over the stop control mode from the hydrogen no-purge mode to the hydrogen purge mode, when the observed temperature is not higher than a preset level.
6. The power system in accordance with claim 2, the power system further comprising:
a temperature measurement module that measures temperature at a preset position in the power system,
wherein the predetermined parameter includes a parameter representing the observed temperature, and
the stop control module switches over the stop control mode from the hydrogen no-purge mode to the hydrogen purge mode, when the observed temperature is not higher than a preset level.
7. The power system in accordance with claim 1, the power system further comprising:
a booster mechanism that boosts up a pressure of hydrogen in the hydrogen supply line,
wherein the stop control module controls the booster mechanism to boost up the pressure of hydrogen in the hydrogen supply line, in the setting of the hydrogen no-purge mode to the stop control mode.
8. The power system in accordance with claim 1, the power system further comprising:
a temperature retention module that keeps temperature in the hydrogen separation module,
wherein the stop control module controls the temperature retention module to keep the temperature in the hydrogen separation module, in the setting of the hydrogen no-purge mode to the stop control mode.
9. The power system in accordance with claim 8, wherein the stop control module stops the operation of the temperature retention module, when the stop control in the hydrogen no-purge mode continues for at least a preset time period.
10. The power system in accordance with claim 1, wherein the stop control module actuates the purge gas supply module on the condition that hydrogen remains in the hydrogen separation module, in the setting of the hydrogen no-purge mode to the stop control mode.
11. The power system in accordance with claim 10, wherein the stop control module stops the operation of the purge gas supply module after elapse of a predetermined time period since a start of actuation of the purge gas supply module, in the setting of the hydrogen no-purge mode to the stop control mode.
12. The power system in accordance with clam 1, the power system further comprising:
a restart request input module that receives a restart request to restart the fuel gas generation system, where the restart request includes an output demand to the fuel cells; and
a material supply control module that regulates a supply of the material to the chemical reaction module, in response to the output demand,
the material supply control module supplying a greater amount of the material to the chemical reaction module than a normal supply in a state of normal operations, in response to input of the restart request into the restart request input module, after a start of the stop control in the hydrogen purge mode.
13. The power system in accordance with claim 12, wherein the material supply control module supplies the greater amount of the material to the chemical reaction module than the normal supply in the state of normal operations, only when the output demand is not greater than a preset level after a start of the stop control in the hydrogen purge mode.
14. The power system in accordance with claim 1, the power system further comprising:
a secondary battery; and
a power supply control module that controls supply of electric power from the secondary battery according to a state of the stop control of the fuel cells.
15. The power system in accordance with claim 14, the power system further comprising:
an output demand input module that receives an output demand to the power system,
wherein in response to the output demand of not greater than a preset level, the power control module controls the secondary battery to output electric power and the stop control module executes the stop control in the hydrogen no-purge mode.
16. The power system in accordance with claim 14, the power system comprising:
a state-of-charge measurement module that measures a state of charge of the secondary battery,
wherein the stop control module executes the stop control in the hydrogen purge mode, when the observed state of charge is not higher than a preset level.
17. A mobile object having a motor as a driving source, the mobile object comprising the power system in accordance with claim 2 as a power source of the motor.
18. The mobile object in accordance with claim 17, wherein the predetermined parameter includes a parameter representing an on-off state of a starter switch of the motor, and
the stop control module executes the stop control in the hydrogen purge mode when the starter switch is off.
19. A mobile object having a motor as a driving source, the mobile object comprising the power system in accordance with claim 1 as a power source of the motor.
20. The mobile object in accordance with claim 19, the mobile object further comprising:
an operation state input module that inputs an operation state of a manipulation unit for moving the mobile object; and
a restart control module that restarts the fuel gas generation system when the input operation state allows for movement of the mobile object, in the setting of the hydrogen purge mode to the stop control mode.
21. The mobile object in accordance with claim 19, the mobile object further comprising:
a moving speed measurement module that measures a moving speed of the mobile object; and
a restart control module that restarts the fuel gas generation system when the observed moving speed exceeds a preset level, in the setting of the hydrogen purge mode to the stop control mode.
22. The mobile object in accordance with claim 21, the power system further comprising:
a restart request input module that receives a restart request to restart the fuel gas generation system, where the restart request includes an output demand to the fuel cells,
the mobile object further comprising:
a temperature measurement module that measures temperature at a preset position in the fuel gas generation system,
wherein the stop control module warms up the fuel gas generation system in response to input of the restart request into the restart request input module, when the observed temperature is not higher than a preset lower limit, in the setting of the hydrogen purge mode to the stop control mode.
23. The mobile object in accordance with claim 20, the power system further comprising:
a restart request input module that receives a restart request to restart the fuel gas generation system, where the restart request includes an output demand to the fuel cells,
the mobile object further comprising:
a temperature measurement module that measures temperature at a preset position in the fuel gas generation system,
wherein the stop control module warms up the fuel gas generation system in response to input of the restart request into the restart request input module, when the observed temperature is not higher than a preset lower limit, in the setting of the hydrogen purge mode to the stop control mode.
24. A mobile object having a motor as a driving source, the mobile object comprising the power system in accordance claim 3 as a power source of the motor.
25. A mobile object having a motor as a driving source, the mobile object comprising the power system in accordance claim 7 as a power source of the motor.
26. A mobile object having a motor as a driving source, the mobile object comprising the power system in accordance claim 8 as a power source of the motor.
27. A mobile object having a motor as a driving source, the mobile object comprising the power system in accordance claim 10 as a power source of the motor.
28. A mobile object having a motor as a driving source, the mobile object comprising the power system in accordance claim 12 as a power source of the motor.
29. A mobile object having a motor as a driving source, the mobile object comprising the power system in accordance claim 14 as a power source of the motor.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A method of calculating parity, comprising:
dividing, by a client system, a file which is to be stored into chunks of a preset size, and distributively storing the chunks in a plurality of data servers;
sending, by the client system, a data write complete notification message to a metadata server;
storing, by the metadata server, a file sent through the data write complete notification message in a recovery queue;
sending, by the metadata server, a random data server a parity calculation request for the file stored in the recovery queue; and
performing a parity operation by the data server receiving the parity calculation request
wherein the performing of the parity operation includes:
receiving a request for allocating and calculatinq a parity, chunk containing information regarding a stripe from the metadata server,
generating a parity chunk file which is to store parity;
allocating a temporary of a chunk size, which is to be used for the parity operation;
requesting data for parity calculation from a data server storing a data chunk constituting the stripe, and storing received data in the temporary buffer;
storing the data, stored in the temporary buffer, in the parity chunk file when the received data is a first data chunk;
performing the parity operetion upon the data read from the parity chunk file and the data stored in the temporary buffer when the received data is not a first data chunk, and storing the data, stored in the temporary buffer, in the parity chunk file;
sending a parity reflection complete response to the data server sending the data chunk; and
sending a parity calculation complete response to the metadata server when parity operation for every data chunk constituting the stripe is completed.
2. The method of claim 1, wherein, in the distributively storing of the chunks in the plurality of data servers, the divided chunks are distributively stored in a plurality of data servers indicated by the metadata server.
3. The method of claim 1, wherein, in the storing of the file in the recovery queue, a path name or an identifier of the sent file is stored.
4. The method of claim 1, wherein the sending of the parity calculation request to the random data server includes:
acquiring an identifier of the file from the recovery queue;
acquiring metadata information of the file from a metadata storage unit;
determining a stripe requiring parity calculation;
determining a data server that is to store a parity chunk of the stripe; and
requesting the determined data server to allocate and calculate a parity chunk.
5. The method of claim 1, wherein the performing of the parity operation further includes:
allocating, by a data server receiving a data request for the parity calculation, a temporary buffer which is to store data;
reading data from a chunk file and storing the data in the temporary buffer when a chunk temporary file is not present;
when a chunk temporary file is present reading data from the chunk temporary file, storing the data in the temporary buffer, and calculating an intermediate parity; and
sending the data stored in the temporary buffer to a data server requesting data.
6. The method of claim 5, wherein the performing of the parity operation further includes merging the chunk temporary file and the chunk file when a response is received from the data server requesting the data.
7. The method of claim 6, wherein the merging of the chunk temporary file and the chunk file comprises:
checking whether or not every bit of an update bitmap of metadata of the chunk temporary file is 1;
converting the chunk temporary file into the chunk file when every bit is 1;
when the number of 1-bits is greater than the number of 0-bits, copying data of a page of 0-bits from the chunk file to the chunk temporary file, and converting the chunk temporary file into the chunk file; and
when the number of 0-bits is greater than the number of 1-bits, copying data of a page of 1-bits from the chunk temporary file to the chunk file, and deleting the chunk temporary file.
8. The method of claim 1, further comprising processing, by a data server receiving a chunk data read request from the client system, the read request.
9. The method of claim 8, wherein the processing of the read request includes:
checking presence of a chunk temporary file;
when the chunk temporary file is not present, reading data from a chunk file and sending the data to the client system; and
when the chunk temporary file is present, reading data from the chunk temporary file and sending the data to the client system in the case of a page where a bit of an update bitmap of metadata of the chunk temporary file is 1, and reading data from the chunk The and sending the data to the client system in the case of a page where a bit is 0.
10. The method of claim 1, further comprising processing, by a data server receiving a chunk data write request from the client system, the write request.
11. The method of claim 10, wherein the processing of the write request includes:
storing data in a chunk file when a chunk the offset is greater than a size of the chunk file;
checking presence of a chunk temporary file when the chunk file offset is not greater than the size of the chunk file;
reading data of a page which is to be updated from the chunk file to the chunk temporary file when the chunk temporary file is present and storing the data in a corresponding page of the chunk temporary file, and generating a chunk temporary file when the chunk temporary file is not present, then reading data of a page to be updated from the chunk file to the generated chunk temporary file, and storing the data in a corresponding page of the generated chunk temporary file; and
setting a bit corresponding to the updated page to be 1 in an update bitmap of metadata of the chunk temporary file.
12. The method of claim 1, further comprising sending, by the metadata server, a recovery request to a data server which is to store a recovered data chunk.
13. The method of claim 12, further comprising:
requesting, by the data server receiving the recovery request, a data chunk from a data server storing a data chunk constituting a stripe to which recovery data belongs; and
reading, by the data server receiving the request for the data chunk, requested data from a chunk file and sending the data to the data server receiving the recovery request.
14. A method of calculating parity, comprising:
dividing a file into chunks of a preset size and distributively storing the chunks of the file in a plurality of data servers;
storing a file sent through a data write complete notification message in a recovery queue; and
performing a parity operation, comprising:
receiving a request for calculating a parity chunk containing information regarding a stripe comprising a plurality of the divided chunks;
generating a parity chunk file which is to store parity;
allocating a temporary buffer of a chunk size;
requesting data for parity calculation and storing the requested data in the temporary buffer;
storing the data, stored in the temporary buffer, in the parity chunk file when the received data is a first data chunk; and
performing the parity operation upon the data read from the parity chunk file and the data stored in the temporary buffer when the received data is not a first data chunk, and storing the data, stored in the temporary buffer, in the parity chunk file.
15. The method of claim 14 further comprising:
sending a parity calculation complete message when parity operation for every data chunk constituting the stripe is completed.
16. A method of calculating parity, comprising:
dividing a file into chunks of a preset size and distributively storing the chunks of the file in a plurality of data servers;
storing a file in a recovery queue;
processing a read request, comprising:
checking for presence of a chunk temporary file;
when the chunk temporary file is not present, reading data from a chunk file from the divided file, and sending the data to a client system; and
when the chunk temporary file is present, reading data from the chunk temporary file and sending the data to the client system in the case of a page where a bit of an update bitmap of metadata of the chunk temporary file is 1, and reading data from the chunk file and sending the data to the client system in the case of a page where a bit is 0.
17. The method of claim 16 further comprising:
sending a data write complete notification message to a metadata server; and sending, by the metadata server, a random data server a parity calculation request for the file stored in the recovery queue.