Transcript Fuel Cell Systems Engineering - Adirondack Trout & Salmon

Fuel Cell Systems Engineering
Systems Engineering Process
Fuel Cell Systems Engineering, F06
Announcement
• Change of classroom to JEC4034 starting
on Tuesday.
• For the class on Monday, September 11th
study the OTC Solicitation that will be
distributed via email next week.
Fuel Cell Systems Engineering, F06
Lecture 2 Topics
• Re-cap of intro lecture topics
• Systems Engineering as a
process/method
• When & how to apply the Systems
Engineering Process
• Process inputs and outputs
• Group activity
Fuel Cell Systems Engineering, F06
Systems Engineering is a Process
Systems Engineering is an interdisciplinary,
iterative, structured process employed to
increase the probability that a developed
system meets the original user
requirements.
Fuel Cell Systems Engineering, F06
Systems Engineering Objectives
• Reduce Cost
• Reduce Risks
• Increase Probability of Success
Fuel Cell Systems Engineering, F06
Defining the System
• A system is a complex set of interrelated
components working together as an
integrated whole toward some common
objective.
Fuel Cell Systems Engineering, F06
This IS NOT a System
5 Cell PEMFC stack from TDM
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This IS a System
Plug Power’s GenSysTM 5KW System
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Common Systems Elements
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Hardware
Software
People
Environment
Information
Interfaces & integration with other systems
A System of Systems
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Hierarchy of System Levels
• System
• Subsystem
RNG PEMFC System
Thermal
Fuel
Documentation
• Components
Controls
Stack
End Plates
Power Cond.
Cells
• Subcomponents
Bi-Polar plates
• Parts
Membrane
Manifolds
Cooling Plates
MEAs
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GDL
Reformer
Gaskets
Seals
Catalyst
Sub-gasket
Defining the “System”
• It is critical that the boundaries of the “box”
around the system be clearly defined and
understood.
• Failure to do so usually results in a system
that does not meet the expectations of the
user.
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System Life Cycle
• A term used to describe the typical stepwise evolution of a new system from
concept through development, production,
deployment and operation, and eventual
disposal or retirement.
• There are many different System Life
Cycle Models, but all have similarities.
Fuel Cell Systems Engineering, F06
System Life Cycle
Systems Engineering Stages
Concept
Development
Engineering
Development
Post
Development
• Needs Analysis
• Advanced Development
• Production
• Concept Exploration
• Engineering Design
• Operation & Support
• Concept Definition
• Integration & Evaluation
• Retirement
Systems Engineering Phases
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System Life Cycle
• And the life cycle of these two fuel cell
systems will be much different.
UltraCell’s 25W Portable System
Plug Power’s GenSysTM 5KW System
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When to Apply the SE Methodology?
• The amount and rigor of the application of
systems engineering methods is usually
related to the system complexity, and the
probability and consequences of failure
• Space shuttle- very complex, low probability of
failure, very high consequences
• MS Windows- moderate to high complexity, high
probability of failure, low consequences
• FC system for space shuttle?
• UPS FC system?
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Project Cost vs. Time
100
Final Cost Determined
Project cost- %
80
60
40
Actual Cost
Realized
20
Concept Dev.
Engineering Dev.
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Post Dev.
Retirement
SE Process- The 50,000ft View
Process
Inputs
Requirements
Analysis
Design
Validation
Process
Outputs
Functional
Definition
Physical
Definition
Although the specific activities may change slightly depending on the
particular system and developmental stage, the general process is similar.
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An Iterative Process
• The Systems Engineering Process is an
iterative process that is applied during
each successive stage of the system life
cycle.
• At each successive iteration the inputs and
outputs become more refined and
detailed.
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Project Initiation
• Needs based development– There is either a real or perceived shortcoming(s)
with an existing system or process
– Project is typically initiated by the user
• Opportunity based development– The emergence of a new technology creates a
new market opportunity (real or perceived)
– Project is typically initiated by the system
developer
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Process Inputs
• User needs/objectives/requirements
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Missions
Measures of effectiveness
Environments
Constraints
Precursor system or technology
Outputs from prior development efforts
Program plans
Specifications and standards
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Requirements Analysis
• Organize inputs: needs; requirements; plans;
schedule; models; precursor designs
• Understand the objectives in terms of the “why”
associated with each requirement re: operational
needs, constraints, environment, schedule, etc. e.g.
“improved responsiveness”
• Clarify the user needs- “What” the system must do,
and “how well” it must do it, e.g.
– Increased range & speed; stop & fire within x sec.;
day/night vision; on-board processors for critical functions
• Quantify the needs whenever possible
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Functional Definition
• Translate all requirements into functional “what”
statements. Typically action words are used, e.g.
“stop and fire within x seconds.”
• Allocate functional requirements into basic
functional elements, e.g.
– Provide secure communications
– Provide automated fuse setting
– Provide automated location and direction data for
armament
– Provide for on-board ballistic computation
• Define functional interactions, e.g. commo. >
location> ballistics > fuse setting
Fuel Cell Systems Engineering, F06
Physical Definition
• Translate functional requirements (“what”) into
multiple technical approaches (“how”)
• Conduct trade-off analysis to determine ”best
technical approach.” Best is determined at the
system level by the best combination of
performance, risk, cost and schedule, based on
previously determined prioritized criteria
(measures of effectiveness).
• Define the system design to the required level of
detail.
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Design Validation
• Does the selected design meet the
requirements and constraints?
– Models of system performance (physical,
mathematical, simulations, logical)
– Testing and analysis of results.
• Re-evaluate the requirements and
constraints.
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Process Outputs
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Refined plans
Updated requirements
Decision support information
Results of analyses
Designs
Specifications
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Situation
• Small gasoline engines, such as those on lawn
mowers are a significant source of pollution.
• Small gasoline engines are not fuel efficient.
• Standard electric lawn mowers require an
extension cord (hazard & inconvenient).
• Batteries do not have the power density needed
for a lawn mower.
• A number of states are considering legislation
that will impose emission standards and fuel
economy standards on small gasoline engines.
• It is anticipated that legislation will drive the cost
of lawnmowers up significantly.
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Opportunity
• There is a perceived opportunity to
develop a fuel cell powered lawn mower
that will overcome the shortcomings of
current lawnmowers.
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Group Activity
• From the perspective of the user, what are
the requirements associated with a fuel
cell powered lawnmower?
• From the perspective of the developer,
how would you go about determining IF
there is a feasible (fuel cell) solution to the
perceived need?
Fuel Cell Systems Engineering, F06