Fuel Cell Subsystem Scavenging Control via Temperature Detection

Solution Overview

Problem

In fuel cell systems with multiple subsystems, temperature variations among subsystems can lead to inappropriate timing for the scavenging process, particularly when residual water may freeze, due to differences in environmental conditions.

Innovation Solution

A fuel cell system with a control unit that determines the temperature of each subsystem and commands scavenging only in the subsystem with the lowest temperature, ensuring all subsystems perform scavenging at the appropriate time, reducing the likelihood of freezing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the scavenging process is uniformly performed on all subsystems, then the control logic is simple, but the scavenging timing may be inappropriate for certain subsystems with different temperature conditions

Engineering Contradiction:

Improvecontrol logic simplicityVSAvoidscavenging timing appropriateness

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The patent applies local quality by making the scavenging control strategy subsystem-specific. The control unit determines the temperature of each subsystem individually and performs scavenging based on local temperature conditions rather than applying a uniform control strategy to all subsystems. This resolves the contradiction by adapting the control approach to local thermal conditions while maintaining overall system coordination.

Inventive Principle:

Principle #3Local quality

2Reliability

If the scavenging process is performed in all subsystems, then all subsystems are protected from freezing, but energy consumption increases

Engineering Contradiction:

Improvefreezing protectionVSAvoidenergy consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent applies partial action by performing scavenging only in subsystems where it is actually needed based on temperature conditions. The control unit determines the temperature of each subsystem and commands scavenging only for subsystems meeting the freezing risk criteria, rather than performing scavenging in all subsystems unconditionally. This reduces energy consumption while maintaining adequate freezing protection.

Inventive Principle:

Principle #16Partial or excessive action

3Reliability

If the scavenging process is performed in all subsystems, then all subsystems are protected from freezing, but the system complexity increases

Engineering Contradiction:

Improvefreezing protectionVSAvoidcontrol system complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies partial action by performing scavenging only in subsystems where it is actually needed based on temperature conditions. The control unit determines the temperature of each subsystem and commands scavenging only for subsystems meeting the freezing risk criteria, rather than performing scavenging in all subsystems unconditionally. This reduces energy consumption while maintaining adequate freezing protection.

Inventive Principle:

Principle #16Partial or excessive action

Solution Approach 2:

The patent applies universality by using a single control unit that can manage multiple subsystems with different temperature conditions. The control unit performs temperature determination and scavenging control for all subsystems through a unified control logic, avoiding the need for separate control systems for each subsystem while still providing customized control based on local conditions.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS11152632B2Fuel cell system and control method

Publication Date: 2021.10.19 TOYOTA JIDOSHA KK

AI summary

A fuel cell system is equipped with a plurality of subsystems. Each of the plurality of the subsystems is equipped with a fuel cell stack, a temperature sensor, a scavenging device, and a control unit. The control unit of that one of the subsystems having the fuel cell stack whose temperature is specified as being the lowest among the plurality of the subsystems when the fuel cell system is stopped from operating performs scavenging control including a determination on the carrying out of scavenging in the subsystem and the issuance of a command to carry out scavenging to all the subsystems in accordance with the determination.