Fuel Cell Cooling Pump Timing for Air Removal and Heat Control

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Solution Overview

Problem

Conventional fuel cell systems face thermal deterioration due to air accumulation in the cooling water circulation channel, which can lead to increased internal temperatures exceeding the heatproof limits of components, causing functional deterioration of the pump and potentially damaging the fuel cell.

Innovation Solution

Implementing a control method that distinguishes between two stop times for the circulation pump's intermittent operation: a longer first stop time during water filling to ensure air removal and a shorter second stop time during electricity generation to maintain the fuel cell within safe temperature limits, thereby preventing thermal deterioration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the circulation pump operates intermittently to remove air from the cooling water circulation channel, then air removal effectiveness is improved, but the fuel cell internal temperature increases excessively

Engineering Contradiction:
Improveair removal effectivenessVSAvoidfuel cell internal temperature
Core Design Contradiction:
ReliabilityVSTemperature

Solution Approach 1:

The patent applies dynamics by making the pump operation mode adjustable based on operating conditions. The controller switches between intermittent operation (for air removal) and continuous operation (for temperature control) depending on whether the fuel cell is starting up or already operating, optimizing both air removal effectiveness and temperature management dynamically

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the operational parameters of the circulation pump based on the fuel cell's operating state. During startup, the pump operates intermittently with longer stop periods to maximize air removal. During normal operation, the pump operates continuously or with shorter interruptions to maintain appropriate cooling, thus adjusting parameters to balance air removal and temperature control

Inventive Principle:
Principle #35Parameter changes

2Temperature

If the circulation pump operates continuously to maintain fuel cell temperature, then temperature control is improved, but air accumulation in the circulation channel increases

Engineering Contradiction:
Improvefuel cell internal temperatureVSAvoidpump function
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The patent implements periodic action by scheduling intermittent pump operations at appropriate intervals during fuel cell operation. This periodic interruption allows air to rise and be removed from the circulation channel while maintaining overall continuous cooling, preventing both air accumulation and excessive temperature rise

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent applies preliminary action by performing air removal operations during startup before full power operation begins. This preliminary air removal prevents air accumulation that would otherwise occur during continuous operation, maintaining pump reliability while enabling effective temperature control

Inventive Principle:
Principle #10Preliminary action

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 approach effectively removes air from the circulation channel and prevents thermal deterioration of fuel cell components by ensuring the circulation pump operates within safe temperature ranges during electricity generation.

Implementation Method 1

a circulation channel through which cooling water circulates to exchange heat with a fuel cell

Methodology Applied
Scientific EffectHeat exchange: Convection

Implementation Method 2

a circulation pump that delivers the cooling water to the circulation channel

Methodology Applied
Scientific EffectPumping: Pump

Implementation Method 3

air dissolved in cooling water generally appears as bubbles (air) with a rise of a temperature of cooling water circulating through the cooling water circulation channel

Methodology Applied
Scientific EffectGas dissolution and bubble formation: Bubble

Data Source

PatentEP3279991B1Fuel cell system and operation method therefor
Publication Date: 2023.11.01 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD
  • EP3279991B1 patent drawingFigure 1
  • EP3279991B1 patent drawingFigure 2
  • EP3279991B1 patent drawingFigure 3

AI summary

When a stop time is defined as a time from an operation stop to an operation restart of an intermittent operation of circulation pump (4) which circulates cooling water through circulation channel (3) for heat exchange between the cooling water and fuel cell (2), controller (15) intermittently operates circulation pump (4) during a start of fuel cell (2) and electricity generation of fuel cell (2), such that a second stop time corresponding to a stop time of the intermittent operation during electricity generation by fuel cell (2) is shorter than a first stop time corresponding to a stop time of the intermittent operation during the start of fuel cell (2). Accordingly, air remaining in circulation channel (3) through which cooling water circulates for heat exchange with fuel cell (2) can be reliably removed, and thermal deterioration of constituent elements of fuel cell (2) can be prevented.