Fuel Cell Device Flow Regulation for Natural Gas Composition Fluctuations

Solution Overview

Problem

Fuel cell devices operating with natural gas face challenges in maintaining consistent operation due to fluctuations in natural gas composition, leading to deviations in oxygen-to-carbon ratio and fuel efficiency, which can result in carbon deposits and fuel starvation.

Innovation Solution

A control unit is implemented to regulate the inlet volume and mass flow of natural gas based on the output flows from the reformer unit and fuel cell unit, using a control valve and flow meters to maintain constant output flows, and a recirculation circuit to manage anode exhaust gas, ensuring stable operation despite composition fluctuations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If natural gas is supplied to the fuel cell device without flow regulation, then the device can operate with simple supply infrastructure, but the oxygen-to-carbon ratio and fuel efficiency deviate due to composition fluctuations

Engineering Contradiction:

Improvesupply infrastructure complexityVSAvoidoperational consistency

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The control unit continuously monitors the actual volume flow of natural gas and compares it with the desired volume flow, then adjusts the control valve accordingly to maintain the desired flow rate despite composition fluctuations in the natural gas supply

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The system dynamically adjusts the volume flow parameter of natural gas based on real-time composition variations, changing the flow rate to compensate for fluctuations in calorific value and maintain stable oxygen-to-carbon ratio and fuel efficiency

Inventive Principle:

Principle #35Parameter changes

2Reliability

If the inlet volume flow of natural gas is regulated to compensate for composition fluctuations, then operational consistency is improved, but device complexity increases due to control components

Engineering Contradiction:

Improveoperational consistencyVSAvoidcontrol system complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The control unit continuously monitors the actual volume flow of natural gas and compares it with the desired volume flow, then adjusts the control valve accordingly to maintain the desired flow rate despite composition fluctuations in the natural gas supply

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The control system automatically adjusts the natural gas flow rate based on real-time composition data and operational parameters, enabling self-regulation without requiring manual intervention or complex external control infrastructure

Inventive Principle:

Principle #25Self-service

3Adaptability or versatility

If natural gas composition fluctuates, then supply flexibility is maintained, but carbon deposits form due to oxygen-to-carbon ratio deviations

Engineering Contradiction:

Improvesupply flexibilityVSAvoidcarbon deposits

Core Design Contradiction:

Adaptability or versatilityVSObject-generated harmful factors

Solution Approach 1:

The system dynamically adjusts the volume flow parameter of natural gas based on real-time composition variations, changing the flow rate to compensate for fluctuations in calorific value and maintain stable oxygen-to-carbon ratio and fuel efficiency

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The control unit continuously monitors the actual volume flow of natural gas and compares it with the desired volume flow, then adjusts the control valve accordingly to maintain the desired flow rate despite composition fluctuations in the natural gas supply

Inventive Principle:

Principle #23Feedback

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 solution effectively compensates for natural gas composition fluctuations, minimizing deviations in oxygen-to-carbon ratio and fuel efficiency, reducing the risk of carbon deposits and fuel starvation, and maintaining consistent fuel cell device performance.

Implementation Method 1

a reformer unit (16a, 16b), which is intended to at least partially reform the natural gas (12a, 12b)

Methodology Applied

Scientific EffectSteam reforming:

Implementation Method 2

by partial oxidation

Methodology Applied

Scientific EffectPartial oxidation:

Implementation Method 3

by autothermal reforming

Methodology Applied

Scientific EffectAutothermal reforming:

Implementation Method 4

a fuel cell unit (14a, 14b), in particular a solid oxide fuel cell (SOFC), which is intended to generate at least one chemical reaction energy of at least one, in particular continuously supplied, fuel gas, in particular hydrogen, and at least one oxidizing agent, in particular oxygen

Methodology Applied

Scientific EffectElectrochemical reaction:

Data Source

PatentEP3586390B1Fuel cell device

Publication Date: 2021.06.09 ROBERT BOSCH GMBH

Figure 1
Figure 2

AI summary

The invention relates to a fuel cell device (10a; 10b), which is provided to be operated with a natural gas (12a; 12b), having a fuel cell unit (14a; 14b) and a reformer unit (16a; 16b), which is provided to at least partially reform the natural gas (12a; 12b). According to the invention, the fuel cell device (10a; 10b) has a regulating unit (18a; 18b), which is provided at least to regulate an inlet volume flow and/or inlet mass flow (20a; 20b) of the natural gas (12a; 12b) according to at least one volume flow and/or mass flow (22a; 22b) at an output (24a; 24b) of the reformer unit (16a; 16b) and/or according to at least one volume flow and/or mass flow (26a; 26b) at an anode output (28a; 28b) of the fuel cell unit (14a; 14b).