Exhaust hydrogen dilution device
An exhaust hydrogen dilution device includes a purge receiving chamber to store hydrogen purged from a fuel cell of a fuel cell system and an air passage chamber adjoining the purge receiving chamber. Diluter gas flows through the air passage chamber. An interface member between the chambers comprises an interface member having first and second vents respectively on an upstream side and a downstream side. A pressure loss at the first vent is greater than or equal to a pressure loss at the second vent. Some of the diluter gas flows into the purge receiving chamber through the first vent and is mixed with the hydrogen into a mixed gas that flows toward the second vent. The pressure losses are adjusted such that a ratio of the hydrogen flowing into the air passage chamber to a total amount of gases flowing through the air passage chamber is 4% or lower.
1 . An exhaust hydrogen dilution device to be mounted on a fuel cell system, the exhaust hydrogen dilution device comprising:
a purge receiving chamber configured to temporarily store hydrogen that is to be purged intermittently from a fuel cell of the fuel cell system;
an air passage chamber through which diluter gas is to flow, the air passage chamber adjoining the purge receiving chamber; and a purge nozzle coupled to the purge receiving chamber, and comprising a distal end configured to discharge the hydrogen into the purge receiving chamber, wherein
an interface region between the purge receiving chamber and the air passage chamber comprises an interface member having a first vent on an upstream side and a second vent on a downstream side,
a pressure loss at the first vent is greater than or equal to a pressure loss at the second vent,
some of the diluter gas flows from the air passage chamber into the purge receiving chamber through the first vent and is mixed with the hydrogen stored in the purge receiving chamber into a mixed gas that flows toward the second vent,
the pressure loss at the first vent and the pressure loss at the second vent are adjusted such that a ratio of the hydrogen flowing into the air passage chamber through the second vent is 4% or lower with respect to a total amount of gases that flow through the air passage chamber,
the mixed gas in the purge receiving chamber flows into the air passage chamber through the second vent and is diluted with the diluter gas,
the interface member inclines up to the second vent with the second vent residing at a lowest position in the purge receiving chamber,
the interface member includes a first portion between the first vent and the second vent, and a second portion between the second vent and a side wall of the purge receiving chamber at the downstream side,
the distal end of the purge nozzle is at a space within the purge receiving chamber above the first portion, and
the interface member is configured to rectify a flow of the hydrogen from the purge nozzle toward the second vent by a structure including:
(i) the purge receiving chamber providing for an unobstructed flow path between the purge nozzle and the second vent; and
(ii) the first portion inclining at a first angle with respect to the second vent, and the second portion inclines at a second angle greater than the first angle with respect to the second vent.
2 . The exhaust hydrogen dilution device according to claim 1 , further comprising:
a water guiding structure configured to guide liquid to be generated in the purge receiving chamber to flow toward the second vent.
3 . The exhaust hydrogen dilution device according to claim 1 , further comprising a supplemental gas supply device supplying supplemental gas into the air passage chamber,
wherein the supplemental gas supply device provides gas comprising oxygen to the air passage chamber when a flow rate of air discharged from the fuel cell is below a certain level as the diluter gas.
4 . The exhaust hydrogen dilution device according to claim 1 , further comprising
a water blocking member that has a cylindrical shape being provided in the purge receiving chamber on the interface member in such a manner as to surround the first vent provided in the interface member, wherein the blocking member is configured to block liquid to be generated in the purge receiving chamber from closing the first vent.
5 . The exhaust hydrogen dilution device according to claim 1 , further comprising a water blocking member that has a cylindrical shape being provided in the purge receiving chamber on the interface member in such a manner as to surround the first vent provided in the interface member, wherein
the blocking member is configured to block liquid to be generated in the purge receiving chamber from closing the first vent, and comprises an upstream part and a downstream part nearer to the second vent than the upstream part, and
the downstream part is lower than the upstream part.
6 . The exhaust hydrogen dilution device according to claim 1 , further comprising:
a water blocking member surrounding the first vent and being configured to block liquid to be generated in the purge receiving chamber from closing the first vent.
7 . The exhaust hydrogen dilution device according to claim 6 , further comprising:
a water guiding structure configured to guide the liquid to flow toward the second vent.
8 . The exhaust hydrogen dilution device according to claim 1 , further comprising:
a turbulence generating member capable of generating turbulence in a region of the air passage chamber, the region residing on the downstream side with respect to the first vent.
9 . The exhaust hydrogen dilution device according to claim 8 , further comprising:
a water guiding structure configured to guide liquid to be generated in the purge receiving chamber to flow toward the second vent.
10 . The exhaust hydrogen dilution device according to claim 8 , further comprising:
a water blocking member surrounding the first vent and being configured to block liquid to be generated in the purge receiving chamber from closing the first vent.
11 . The exhaust hydrogen dilution device according to claim 10 , further comprising:
a water guiding structure configured to guide the liquid to flow toward the second vent.