Fuel Cell Valve Device Heating for Freezing Prevention

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Solution Overview

Problem

Existing fuel cell systems face challenges in effectively suppressing freezing of valve devices and rapidly defrosting them due to complex structures and inefficient heat distribution from Positive Temperature Coefficient (PTC) heaters.

Innovation Solution

A fuel cell system with a simplified structure that includes a gas liquid separator and a valve device with a heating device integrated into the fluid inlet, allowing direct heating of fluids and water, and using a PTC heater controlled by a unit to maintain the valve main body above freezing temperatures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a PTC heater is provided for the shaft and seal portion of the valve device to prevent freezing, then the valve device can be heated, but the structure of the valve device becomes complicated

Engineering Contradiction:

Improvefreezing preventionVSAvoidvalve device structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The heating function is extracted from the valve device structure and relocated to the fluid inlet component. The heating device is integrated into the fluid inlet that guides fluid from the gas liquid separator to the valve main body, separating the heating function from the valve mechanism itself and simplifying the overall valve device structure.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The fluid inlet acts as an intermediary component that serves dual purposes: guiding fluid from the gas liquid separator to the valve main body and housing the heating device. This intermediary structure allows heat to be applied to the fluid and valve components without requiring direct integration of the heater into the valve mechanism.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Temperature

If a PTC heater is used to heat the shaft and seal portion, then heating is provided, but the heat is radiated to the outside through the valve device body making it ineffective for suppressing freezing

Engineering Contradiction:

Improveheating capabilityVSAvoidheat radiation loss

Core Design Contradiction:

TemperatureVSLoss of energy

Solution Approach 1:

The heating device is positioned locally at the fluid inlet where fluid containing water enters the valve device. This localized heating approach targets the specific area where freezing is most likely to occur (the fluid passage and valve components) rather than heating the entire valve device body, thereby reducing energy loss through radiation to non-critical areas.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The heating device pre-heats the fluid and fluid inlet components before the fluid reaches the valve main body and shaft. By applying heat in advance at the fluid inlet, the system prevents freezing proactively rather than attempting to heat already-frozen components, improving heating efficiency and reducing energy waste.

Inventive Principle:

Principle #10Preliminary action

3Reliability

If the valve device is frozen, then freezing occurs, but it is not possible to defrost the frozen valve device rapidly with the existing structure

Engineering Contradiction:

Improveoperational continuityVSAvoiddefrosting time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The heating device continuously maintains the fluid inlet and incoming fluid above freezing temperature, preventing ice formation in the first place. This preliminary preventive heating eliminates the need for lengthy defrosting operations and ensures rapid restoration of functionality if freezing does occur.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The passive thermal management approach is replaced with an active heating system that uses electrical energy to maintain temperatures above freezing. This substitution allows for rapid response to freezing conditions and quick defrosting capability compared to passive thermal design.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This configuration effectively prevents freezing and rapidly defrosts the valve device, reducing electrical power consumption and maintaining system efficiency.

Implementation Method 1

A heating device is provided at an inner hole of the fluid inlet... it is possible to directly heat the fluid (off gas and water) guided from the gas liquid separator to the valve main body by the heating device

Methodology Applied

Scientific EffectJoule heating: Joule Heating

Implementation Method 2

a positive temperature coefficient (PTC) heater is provided for a shaft and a seal portion of the valve device... the heat produced by the PTC heater tends to be radiated from the shaft and the seal portion to the outside

Methodology Applied

Scientific EffectPositive temperature coefficient effect: Thermistor

Data Source

PatentUS11171346B2Fuel cell system

Publication Date: 2021.11.09 HONDA MOTOR CO LTD

AI summary

A fuel cell system includes a gas liquid separator and a valve device. The gas liquid separator separates water from a fuel off gas discharged from a fuel cell stack. The valve device is provided in a discharge channel for discharging water separated from the gas liquid separator. The valve device includes a fluid inlet for guiding fluid at least containing water in the gas liquid separator toward the valve main body. A heating device is provided at an inner hole of the fluid inlet.