Fuel Cell Systems Engineering Process Announcement Change of

Fuel Cell Systems Engineering Process

Announcement • Change of classroom to JEC 4034 starting on Tuesday. • For the class on Monday, September 11 th study the OTC Solicitation that will be distributed via email next week.

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

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.

Systems Engineering Objectives • Reduce Cost • Reduce Risks • Increase Probability of Success

Defining the System • A system is a complex set of interrelated components working together as an integrated whole toward some common objective.

This IS NOT a System 5 Cell PEMFC stack from TDM

This IS a System Plug Power’s Gen. Sys. TM 5 KW System

Common Systems Elements • • • Hardware Software People Environment Information Interfaces & integration with other systems A System of Systems

Hierarchy of System Levels RNG PEMFC System • System • Subsystem Thermal Fuel Documentation • Components Controls Stack End Plates Power Cond. Cells • Subcomponents Bi-Polar plates • Parts Membrane Manifolds Cooling Plates MEAs 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.

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.

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

System Life Cycle • And the life cycle of these two fuel cell systems will be much different. Ultra. Cell’s 25 W Portable System Plug Power’s Gen. Sys. TM 5 KW System

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?

Project Cost vs. Time 100 Final Cost Determined Project cost- % 80 60 40 Actual Cost Realized 20 Concept Dev. Engineering Dev. Post Dev. Retirement

SE Process- The 50, 000 ft 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.

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.

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

Process Inputs • User needs/objectives/requirements – – • • Missions Measures of effectiveness Environments Constraints Precursor system or technology Outputs from prior development efforts Program plans Specifications and standards

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

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

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.

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.

Process Outputs • • • Refined plans Updated requirements Decision support information Results of analyses Designs Specifications

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.

Opportunity • There is a perceived opportunity to develop a fuel cell powered lawn mower that will overcome the shortcomings of current lawnmowers.

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?