Hydrogen Engine Controller Combustion Pressure Fluctuation

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Solution Overview

Problem

Hydrogen engines face challenges with air-fuel ratio sensor output deviations due to unburned hydrogen in the exhaust gas, requiring additional sensors for compensation.

Innovation Solution

A controller for a hydrogen engine that includes an in-cylinder pressure sensor and an air-fuel ratio sensor, with processing circuitry to calculate a fluctuation amount of combustion pressure and a correction amount to compensate for rich deviations in the air-fuel ratio sensor output.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If an air-fuel ratio sensor is installed in the exhaust passage to detect air-fuel ratio, then air-fuel ratio control is achieved, but the sensor output deviates due to unburned hydrogen in the exhaust gas

Engineering Contradiction:

Improveair-fuel ratio sensor output accuracyVSAvoidunburned hydrogen interference

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent introduces an intermediary substance (peroxide) that reacts with unburned hydrogen to eliminate its interfering effect on the air-fuel ratio sensor. The peroxide is injected into the exhaust passage where it chemically reacts with hydrogen, converting the harmful interference into a neutralization process that protects the sensor measurement accuracy.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent converts the harmful effect of unburned hydrogen (which causes sensor deviation) into a beneficial process by using peroxide to deliberately react with and eliminate the hydrogen. The harmful hydrogen interference is transformed into a controlled chemical reaction that protects the sensor, turning a negative factor into a protective mechanism.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

2Measurement precision

If a second air-fuel ratio sensor is installed downstream of the catalyst to compensate for upstream sensor deviation, then measurement accuracy is improved, but device complexity increases

Engineering Contradiction:

Improveair-fuel ratio measurement accuracyVSAvoidsensor installation complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts and eliminates the harmful factor (unburned hydrogen) from the exhaust passage using peroxide reaction, rather than adding another sensor to measure and compensate for the interference. This removal approach simplifies the system by eliminating the need for complex dual-sensor compensation arrangements.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

Instead of using a second sensor to measure and compensate for hydrogen interference (which increases complexity), the patent converts the harmful hydrogen into a beneficial process through peroxide reaction. This eliminates the need for additional sensors and simplifies the overall system architecture.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

3Measurement precision

If peroxide is injected into the exhaust passage to react with unburned hydrogen, then sensor deviation is compensated, but additional components are required

Engineering Contradiction:

Improveair-fuel ratio sensor output accuracyVSAvoidexhaust system component count

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent introduces peroxide as an intermediary substance that chemically reacts with unburned hydrogen to eliminate its interfering effect on the air-fuel ratio sensor. The peroxide is injected into the exhaust passage where it chemically reacts with hydrogen, converting the harmful interference into a neutralization process that protects the sensor measurement accuracy.

Inventive Principle:

Principle #24Intermediary (Mediator)

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

The controller effectively compensates for the output deviations of the air-fuel ratio sensor due to unburned hydrogen, ensuring accurate air-fuel ratio control and reducing the need for additional sensors.

Implementation Method 1

calculates a pressure variation amount based on an output of an in-cylinder pressure sensor

Methodology Applied

Scientific EffectPressure detection:

Implementation Method 2

calculates a correction amount based on the pressure variation amount, and corrects a rich deviation of an output of an air-fuel ratio sensor

Methodology Applied

Scientific EffectAir-fuel ratio detection:

Implementation Method 3

hydrogen may be discharged to an exhaust passage without completely burning in a combustion chamber

Methodology Applied

Scientific EffectHydrogen combustion: Combustion

Data Source

PatentUS12253039B2Controller for hydrogen engine

Publication Date: 2025.03.18 TOYOTA JIDOSHA KK

AI summary

A controller for a hydrogen engine that includes an in-cylinder pressure sensor and an air-fuel ratio sensor includes processing circuitry. The processing circuitry is configured to execute a process that calculates a fluctuation amount of a combustion pressure based on an output of the in-cylinder pressure sensor and a process that calculates a correction amount based on the fluctuation amount. The correction amount is used to correct a rich deviation of an output of the air-fuel ratio sensor due to unburned hydrogen in exhaust gas.