Manufacturing Model: Simulating SECA Core Technology TIAX LLC - - PowerPoint PPT Presentation

Manufacturing Model: Simulating Relationships Between Performance, Manufacturing, and Cost of Production

TIAX LLC Acorn Park Cambridge, Massachusetts 02140-2390 Reference: TIAX LLC -80034 DE-FC26-02NT41568 SECA Core Technology Program Workshop Sacramento February 19-20, 2003

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1 Technical Issues 2 R&D Objectives and Approach 3 Activities for Phase I

2

Technical Issues

For commercial success, SOFC technologies must ultimately be manufacturable and cost competitive. A number of factors contribute to uncertainty at this time.

Cell design, stack designs, and production processes are still in early

stages of development

SOFC stacks are radically different in structure from any currently mass-

produced ceramic products

Relationships between cell and stack design, design tolerances, and

stack performance are not very well established

3

Technical Issues

Proposed manufacturing processes may be amenable to high-volume production, however, specific processes and sequences must be selected.

Tape Cast Anode Powder Prep Vacuum Plasma Spray Electrolyte Small Powder Prep Screen Print Cathode Small Powder Prep Sinter in Air 1400C Sinter in Air Progressive Rolling of Interconnect Shear Interconnect Vacuum Plasma Spray Slurry Spray Screen Print Slurry Spray Slip Cast

Multi-Fired Process

Finish Edges

Note: Alternative production processes appear in gray to the bottom of actual production processes assumed

Braze Paint Braze

• nto

Interconnect Blanking / Slicing QC Leak Check

Interconnect Fabrication Electrolyte Cathode Anode Stack Assembly Electrical layer

powders are made by ball milling and calcining.

Interconnects are

made by metal forming techniques.

Automated

inspection of the electrical layers

• ccurs after

sintering.

Electrical layer

powders are made by ball milling and calcining.

Interconnects are

made by metal forming techniques.

Automated

inspection of the electrical layers

• ccurs after

sintering.

Illustrative

Process Flow Assumptions Process Flow Process Flow Assumptions Assumptions

Multi-Fired Process Flow Multi Multi-

• Fired Process Flow

Fired Process Flow

Potential Process Flow for Planar Anode-Supported SOFC

4

Technical Issues

Relationships between cell and stack design, design tolerances, stack performance, and process yields are not very well established.

Properties of individual layers, e.g., physical attributes, conductivity

(electrical or ionic), polarization, transport, mechanical, are not well defined as a function of temperature

Manufacturing Options Individual process steps Sequence of steps Impact on Process yield, tolerances, and reproducibility Performance Thermal cycling and Life Cost

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Technical Issues Challenges

A state-of-the-art SOFC manufacturing model will allow developers and NETL to minimize the uncertainties inherently associated with commercialization of a new technology. The model must be able to:

Handle all key SOFC stack components, including ceramic cells and

interconnects

Relate manufactured cost to product quality and likely performance,

taking into account

manufacturing tolerances product yield line speed Address a range of manufacturing volumes, ranging from tens of MW to

hundreds of MW per year

Adapt to individual production processes under development by SECA

industrial teams

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1 Technical Issues 2 R&D Objectives and Approach 3 Activities for Phase I

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R&D Objectives and Approach Objectives

The Manufacturing Model Project will develop a tool to provide guidance to the DOE and SECA development teams on system design and manufacturing processes selection.

Phase I SOFC Manufacturing Model Framework and Demonstration Phase 2 SOFC Manufacturing Model Expansion and Use

Develop model

framework

Demonstrate benefit of

model for system development trade-off analyses

Develop Phase 2 plan Expand Phase I model

framework to other SOFC system designs, alternative materials, and manufacturing processes

Incorporate findings and

research of SECA teams Objectives

Model framework Demonstration of

model capabilities

Workshop with SECA

stakeholders Deliverables

The primary output of the model will be an activity based manufacturing cost for various SOFC system scenarios.

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Phase I will be conducted in three tasks.

Develop architecture of

manufacturing model

Review architecture

with SECA stakeholders

Revise existing model

architecture based on Task 1 workshop

Demonstrate

manufacturing model with baseline SOFC system

Report project progress Prepare Phase I report

that summarizes critical manufacturing steps and performance parameters

Define Phase II

development effort

Workshop with SECA

stakeholders

Definition of model

framework, user interface with model, and critical issues to be assessed, model assumptions

Workshop with SECA

stakeholders

Monthly updates Phase I final report

Objectives Deliverables Task 2 Model Demonstration Task 3 Reporting

Activities for Phase I Tasks

Task 1 Model Framework Development

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Activities for Phase I Deliverables

We anticipate that we will provide DOE and industrial teams with some key conclusions and recommendations:

Identification of critical manufacturing steps and performance parameters if considerable uncertainty exists about these steps, specific additional

SECA R&D objectives may be developed

Refinement of SECA technology cost and performance estimates Definition of desirable next steps

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Model Architecture Modeling Approach Link to Performance/Structural Module

The cost model will be augmented with a SOFC performance model to help relate manufacturing quality to performance.

User Interface SOFC Scenario Compiler Module Activity-Based Cost Model Performance Structural Module Databases

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Model Architecture Modeling Approach Cost Model

The model uses a set of databases to calculate cost for defined production (process flow) scenarios and performance assumptions.

Manufacturing Costs Material Properties Database Material Cost Database Purchased Components Formulation Database Process Database Capital Equipment Database

• Labor
• Real estate
• Overhead

. . .

• Vendors
• Cost vs.

volume . . .

• Density
• Particle size

distribution

• Surface area

. . .

• Cost vs.

volume

• Specifica-

tions . . .

• Anode
• Cathode
• Electrolyte
• Interconnects
• Equipment

process data

• Throughput
• Size limit
• Automation
• Scrap
• Yield
• Cost vs.

product volume

• Process flow
• Equipment options

Calculation Engine (Activity-Based)

• Design
• Performance

Parameters

• Manufacture

Processes and Flow

• Production Scenarios
• Tables
• Graphs
• Crystal Ball

– sensitivity – “frequency distribution” Inputs Outputs (Results)

The model description provides a unified framework for discussion of input parameters of interest to the Team members.

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Model Architecture Performance/Structural Module Capabilities

The module also accounts for all the relevant thermo-electrochemical phenomena which influence cell performance and, ultimately, cost.

Interconnect

• Heat conduction
• Current

conduction Anode and cathode reaction zones

• Electrochemical reactions
• Heat generation

Electrolyte

• Ion conduction
• Heat conduction

Flow passages

• Heat convection
• Plug flow of gas

Anode and cathode porous electrodes

• Heat conduction
• Current conduction
• Species diffusion
• Internal reforming on anode

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Model Architecture Performance/Structural Module Interface with Cost Model

The performance/structural module is used to predict power density, thermal stresses, and other performance factors that influence cost.

Compressive load

• n the cell#

Temperature gradients Material yield Heat conduction Boundary conditions Heat generation Heat convection Current generation Chemical reactions* Stack/cell geometry Electrochemical reactions Power density Stress distribution Defects

Performance/Structural Module Framework

* Internal reforming reactions

# Compressive load needed for establishing contact between different stack layers

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1 Technical Issues 2 R&D Objectives and Approach 3 Activities for Phase I

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Manufacturing Model Technical Issues

We met with the SECA technical teams to discuss what relationships among cell and stack design, design tolerances, stack performance, and process yields should be considered in Phase 1?

Properties of individual layers Thickness and other physical attributes Polarization and conductivity (electrical or ionic) Transport Mechanical Manufacturing Options Individual process steps Sequence of steps Impact on Process yield, tolerances, and reproducibility Performance Thermal cycling and life Cost

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Manufacturing Model Stack Design

We discussed selection of a stack design for demonstration of the model capabilities and an initial assessment of the impact of selected manufacturing/design factors.

What planar stack configuration should

be modeled in Phase I?

Rectangular or circular Co-, counter-, or cross-flow What design details (e.g., seals,

manifolds, insulation) should be included in the Phase I modeling effort?

What size (kW) stack should we

consider?

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Manufacturing Model Performance/Structural Module

What choices affecting both cost and performance should we analyze?

For example, we could consider the impact of layer thickness on system

power and thermal stresses.

Layer Thickness Processing Steps Ohmic Losses Stack Size Thermal Stresses Cracking Failures Part Yield Material Cost Process Cost Area-Specific Resistivity Power Density

Inputs Inputs Performance/Structural Module Performance/Structural Module Cost Model Cost Model

$ kW

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Manufacturing Model Use of Performance/Structural Module

In addition, the Performance/Structural Module could be used for stand- alone simulations to evaluate the sensitivity of particular material or process parameters.

Contact Resistance Contact Area Power Density Surface Finish

Performance/Structural Module Performance/Structural Module

Contact Resistance Pressure Variations Power Density Thickness Variations Mechanical Stresses MEA Warping Cracking Failures Oven Temperature Variations

What design parameters, material properties, or manufacturing conditions are of interest for analysis, either in Phase I or II?

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Manufacturing Model Parameters Baseline Case Design

As a basis for Phase I, we will use an anode supported design. Anode/Electrolyte/Cathode Anode/Electrolyte/Cathode Anode/Electrolyte/Cathode One-Half Interconnect Layer One One-

• Half Interconnect Layer

Half Interconnect Layer

Ni Cermet Anode 700 µm 8YSZ & LSM Cathode 50 µm Y-stabilized ZrO2 Electrolyte 10 µm Ferritic Stainless Steel 4 mm 2 mm

We will only assess the stack costs in this phase. We also considered inclusion of reforming layers or materials in the stack, but have insufficient design information in this Phase of work.

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Manufacturing Model Parameters Performance Parameters

We propose using the following set of operating parameters for the stack.

Parameter Parameter Value/Range

• Cell voltage
• Power Density
• Composition of the reactant

streams

• Gas inlet temperatures
• Fuel utilization
• Cathode stoichiometry
• Cell voltage
• Power Density
• Composition of the reactant

streams

• Gas inlet temperatures
• Fuel utilization
• Cathode stoichiometry
• 0.7 V
• 500 mW/cm2 (not reactant limited)
• Anode: reformate; Cathode: air
• 650°C at the Anode and Cathode
• ~ 50 %
• ~ 5, adjusted to effect an exit temperature of

800°C.

• 0.7 V
• 500 mW/cm2 (not reactant limited)
• Anode: reformate; Cathode: air
• 650°C at the Anode and Cathode
• ~ 50 %
• ~ 5, adjusted to effect an exit temperature of

800°C. Value/Range

The performance model will calculate the current distribution over the electrode, the average power density, and the actual fuel utilization.

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Manufacturing Model Parameters Impact of Layer Thickness

We will look at the trade-offs between layer thickness and their impact

• n performance and cost. The latter impacted by material quantities

and yield.

Layer Nominal Thickness (µm) Remark Anode Material 700

• Minimize thickness to reduce material

weight and resistance

• Impact of thickness on strength and MEA

stress Electrolyte Ni-YSZ 10

• Barrier properties vs thickness critical
• Impact of coating technology and thickness
• n defects

Cathode YSZ 50

• Coating technologies

Interconnect YSZ- LSM

• Roll form technique used in baseline study

Metal 4300

As part of this effort we will look at the impact of the attributes of various process technologies on each layer, types of defects, and number of defects. It will be critical to find relationships between defects, materials, and processes.

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Manufacturing Model Parameters Economies of Scale

We will consider how production volume impacts cost ($/kW).

Assumptions 5 kW unit size unit operations are automated to achieve uniformity and maximize

yield

increasing volume can change equipment scale, speed, material

logistics in the process, and automation of assembly

Parameters Days per week Shifts per day Commercialization (Volume) Steps Production Prototypes Market Entry Market Penetration

Our 1999 study was made assuming 250 MW, however, we have not fixed the volume steps at this time for this project.

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Manufacturing Model Parameters Process Flow Options

We will look at a multi-fired process flow option in Phase I.

Co-fired Process Flow Co Co-

• fired Process Flow

Multi-fired Process Flow Multi Multi-

• f

fired Process Flow ired Process Flow fired Process Flow

Tape Cast Anode Powder Prep Vacuum Plasma Spray Electrolyte Small Powder Prep Screen Print Cathode Small Powder Prep Sinter in Air 1400C Sinter in Air Progressive Rolling of Interconnect Shear Interconnect Vacuum Plasma Spray Slurry Spray Screen Print Slurry Spray Slip Cast

Multi-Fired Process

Finish Edges Braze Paint Braze

• nto

Interconnect Blanking / Slicing QC Leak Check

Interconnect Fabrication Electrolyte Cathode Anode Stack Assembly

Co-Fired Process Flow

Anode Powder Prep Cathode Small Powder Prep Electrolyte Small Powder Prep Tape Cast Tape Cast Tape Cast Blanking / Slicing Stack Calendar Dual Atm Sinter Diamond Grind Edges Slip Cast Slip Cast Slip Cast Roll Calendar Shear Interconnnect Progressive Rolling of Interconnect

Note: Alternative production processes appear in gray to the bottom of actual production processes assumed

Blanking / Slicing Paint Braze

• nto

Interconnect Braze QC Leak Check

Interconnect Fabrication Electrolyte Cathode Anode Stack Assembly

• Individually tape-cast layers
• Laminated together
• Co-fired in one step
• Individually tape-cast layers
• Laminated together
• Co-fired in one step
• Tape-cast anode layer
• Electrolyte and cathode layers applied by coatings
• Sequential firing steps
• Tape-cast anode layer
• Electrolyte and cathode layers applied by coatings
• Sequential firing steps

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Manufacturing Model Discussion Non-Technical Issues

In this phase, we will use generic data, however, for Phase 2 we will have to develop a protocol(s) for protection of proprietary information with participating teams.

Issues:

Protection of individual SECA team

proprietary information

Security of User Interface Access to model Access to process and equipment data

and specifications

Protection of individual SECA team

proprietary information

Security of User Interface Access to model Access to process and equipment data

and specifications

Java based User Interface User User Interface Interface Activity-Based Cost Model Activity-Based Cost Activity-Based Cost Model Model Manufacturing Process Database Manufacturing Manufacturing Process Database Process Database

Manufacturing Process Flow Manufacturing Process Flow Thermal Spray Thermal Spray Tape Casting Tape Casting Sintering Sintering

Materials Database Materials Database Materials Database

LSM LSM YSZ YSZ 316 Stainless Steel 316 Stainless Steel

SOFC Scenario Compiler Module SOFC Scenario SOFC Scenario Compiler Module Compiler Module

Issues: Issues:

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Next Steps Phase I

We expect Phase I to be completed in approximately 3-6 months.

Modify Model and Analyze Selected Scenarios and Issues Layer thickness and processes Economies of scale Discuss results with SECA teams Develop plans for Phase 2 Phase I Final Report

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Activities for Phase I TIAX Team Members

The TIAX core team consists of five members whose backgrounds are particularly appropriate to this project.

Staff Email Telephone

Yong Yang yang.yong@tiax.biz 617-498-6282 Eric Carlson

Project Input

carlson.e@tiax.biz 617-498-5903 Chandler Fulton Principal Investigator fulton.chandler@tiax.biz 617-498-5926 Suresh Sriramulu System modeling sriramulu.suresh@tiax.biz 617-498-6242 Fuel cell technology Manufacturing model