How a Fuel Cell Humidifier Controls Air Moisture with a Smart Valve
This patent describes a fuel cell humidifier that uses two humidifying spaces and a controllable valve to precisely adjust the moisture content of incoming air before it reaches the fuel cell stack, improving efficiency and durability.
Original patent title: “Humidifier for a fuel cell”
This patent describes a fuel cell humidifier that uses two humidifying spaces and a controllable valve to precisely adjust the moisture content of incoming air before it reaches the fuel cell stack, improving efficiency and durability. Granted to Hyundai Motor in 2021 with 13 claims and 4 forward citations, and it is expected to expire in 2039.
Coverage
What does this patent actually cover?
This humidifier prepares incoming air, called inflow gas, for a fuel cell by adding moisture. It features a body with two separate humidifying spaces, a first and a second, each containing special membranes (humidifying membranes) that allow water vapor to pass through. Exhaust gas from the fuel cell, which is naturally humid, flows around these membranes to transfer moisture to the drier inflow gas. A key component is a first valve installed in a 'passing space' (ClaimclaimA numbered sentence at the end of a patent that legally defines what the inventor owns. The most important section.Read more → 1). This valve can direct the inflow gas either through the second humidifying space, bypass the second humidifying space entirely, or split the flow so some goes through and some bypasses. By controlling this valve, the system can select the exact path for the inflow gas, allowing for fine-tuned humidification based on the fuel cell's needs (Claim 1). For example, if the fuel cell needs more humid air, the valve can direct all inflow gas through both humidifying spaces.
The gap
What does this patent NOT cover?
- Does not cover humidifiers that lack a second, distinct humidifying space that can be selectively bypassed by a valve.
- Does not cover systems where the inflow gas always passes through the same humidification path without an adjustable valve.
- Does not cover humidifiers that only use a single humidifying membrane or space for all incoming air.
- Does not cover humidification methods that do not use exhaust gas from the fuel cell stack as the moisture source.
- Does not cover humidifiers where the valve cannot split the inflow gas into both humidified and non-humidified streams simultaneously.
These exclusions are unique to PatentBrief — derived from the actual claim language, not patent-office boilerplate.
Key facts
What made this novel
The clever part is the use of a single, controllable valve to dynamically choose or mix the humidification paths for the incoming air. This allows the system to precisely adjust the moisture level, either by sending all air through a more intense humidification path, bypassing it, or blending the two, all within a compact design.
The Patent Drawing
Schematic visualization of the patent's claim structure. Hand-drawn diagrams in progress for each landmark patent.
Where you've seen this
Real-world examples
Hyundai NEXO fuel cell electric vehicle
Toyota Mirai fuel cell electric vehicle
Honda Clarity Fuel Cell
Stationary fuel cell power generators
Fuel cell buses and heavy-duty trucks
Why it matters
The bigger picture
Fuel cells need precisely humidified air to work efficiently and last longer. If the air is too dry, the fuel cell membranes can dry out and degrade; if it's too wet, water can flood the system. This patent from Hyundai Motor Co. offers a way to dynamically control humidification, which is crucial for optimizing fuel cell performance across different operating conditions, like varying temperatures or power demands. This precise control helps improve the lifespan and reliability of fuel cell vehicles.
Filed
March 28, 2019
Granted
March 16, 2021
Market context
Who's building on this
Companies in this space
Hyundai Motor Co., the assigneeassigneeThe entity that owns the patent — usually the inventor's employer or a company.Read more →, is a major player in fuel cell technology, notably with its NEXO fuel cell electric vehicle. Other automotive manufacturers like Toyota and Honda are also actively developing and deploying fuel cell vehicles and related components. Companies specializing in fuel cell stacks and balance-of-plant components, such as Ballard Power Systems and Plug Power, are continually innovating in this space to improve efficiency and durability.
Market impact
This patent contributes to the ongoing development of more efficient and durable fuel cell systems, particularly in the automotive sector. By offering precise control over humidification, it helps overcome a significant challenge in fuel cell operation, potentially leading to more reliable and longer-lasting fuel cell electric vehicles. This kind of innovation supports the broader market shift towards hydrogen-powered transportation and stationary power generation, making fuel cell technology more competitive with traditional energy sources.
Claim 1 — Plain English
What this patent covers
This humidifier prepares incoming air, called inflow gas, for a fuel cell by adding moisture. It features a body with two separate humidifying spaces, a first and a second, each containing special membranes (humidifying membranes) that allow water vapor to pass through. Exhaust gas from the fuel cell, which is naturally humid, flows around these membranes to transfer moisture to the drier inflow gas. A key component is a first valve installed in a 'passing space' (Claim 1). This valve can direct the inflow gas either through the second humidifying space, bypass the second humidifying space entirely, or split the flow so some goes through and some bypasses. By controlling this valve, the system can select the exact path for the inflow gas, allowing for fine-tuned humidification based on the fuel cell's needs (Claim 1). For example, if the fuel cell needs more humid air, the valve can direct all inflow gas through both humidifying spaces.
The clever bit
The clever part is the use of a single, controllable valve to dynamically choose or mix the humidification paths for the incoming air. This allows the system to precisely adjust the moisture level, either by sending all air through a more intense humidification path, bypassing it, or blending the two, all within a compact design.
What it does not cover
- Does not cover humidifiers that lack a second, distinct humidifying space that can be selectively bypassed by a valve.
- Does not cover systems where the inflow gas always passes through the same humidification path without an adjustable valve.
- Does not cover humidifiers that only use a single humidifying membrane or space for all incoming air.
- Does not cover humidification methods that do not use exhaust gas from the fuel cell stack as the moisture source.
- Does not cover humidifiers where the valve cannot split the inflow gas into both humidified and non-humidified streams simultaneously.
Patent timeline
Application submitted to the patent office
Application published, typically 18 months after filing
Patent officially issued
Patent enters public domain
PatentBrief Score
Impact Score
Early stage
Citation count
14/40
Early citations
Claim breadth
9/20
Moderate scope
Recency
10/20
Granted 5–10 years ago
Assignee scale
0/20
Independent or smaller assigneeassigneeThe entity that owns the patent — usually the inventor's employer or a company.Read more →
PatentBrief Impact Score — based on citation count, claim breadth, recency, and assignee scale. Not a legal assessment.
Heuristic Value Estimate
What this patent might be worth
$42K – $134K
Midpoint $84K · 12.7 yr remaining · industry ×1.4
Heuristic only — blends forward/backward citation counts, claim scope, time remaining, litigation history, and CPC-derived industry baseline. Real valuations need a professional appraisal.
Claim text not yet imported for this patent
The original legal language
Original claims
13 claims as filed with the patent office.
Concepts involved
Citations
Patent lineage
Cite this patent
Kim, H. Y., & OH, S. H. (2021). How a Fuel Cell Humidifier Controls Air Moisture with a Smart Valve (U.S. Patent No. 10,950,878). U.S. Patent and Trademark Office. https://patentbrief.org/patent/us/10950878/humidifier-for-a-fuel-cell
Auto-generated from the patent record. Double-check author order and the issue date against the official USPTO document before submitting.
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Common Questions
Frequently Asked Questions
What does How a Fuel Cell Humidifier Controls Air Moisture with a Smart Valve cover?
This patent describes a fuel cell humidifier that uses two humidifying spaces and a controllable valve to precisely adjust the moisture content of incoming air before it reaches the fuel cell stack, improving efficiency and durability.
Who owns patent US 10950878?
Hyundai Motor owns this patent, granted in 2021.
When does this patent expire?
This patent is expected to expire on March 28, 2039, when the invention enters the public domain.
What is patent US 10950878 cited by?
This patent has been cited by 4 later patents that build on its ideas.
What problem does this patent solve?
Fuel cells need precisely humidified air to work efficiently and last longer. If the air is too dry, the fuel cell membranes can dry out and degrade; if it's too wet, water can flood the system. This patent from Hyundai Motor Co. offers a way to dynamically control humidification, which is crucial for optimizing fuel cell performance across different operating conditions, like varying temperatures or power demands. This precise control helps improve the lifespan and reliability of fuel cell vehicles.
What does this patent NOT cover?
Does not cover humidifiers that lack a second, distinct humidifying space that can be selectively bypassed by a valve.
Patent monitoring