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MHD Advanced Power Train
Prepared For
PITTSBURGH ENERGY TECHNOLOGY CENTER THE UNITED STATES ~EPARTMENT OF ENERGY
Contract DE-AC22-83PC60575
AUGUST 1985
Westinghouse Advanced Energy Systems Division
Large. P.O. Box 10864. Pittsburgh, PA 15236
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DISCLAIMER
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DISCLAIMER
This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees. makes any warranty. express or implied, or assumes any legal liability or responsi- bility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Refer- ence herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recom- mendation. or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof.
WAESD-TR-8 5-0079
MHD Advanced Power Train
Phase I Final Report .
Volume 1 Executive Summary
Prepared For
THE UNITED STATES DEPARTMENT OF ENERGY PITTSBURGH ENERGY TECHNOLOGY CENTER
Government Technical Project Officer: Dr. Harold F. Chambers, Jr
Contract DE-AC22-83PC60575
AUGUST 1985
by A. R. Jones
Project Manager
Westinghouse Advanced Energy Systems Division
Large, P.O. Box 10864. Pittsburgh. PA 15236
DISTRIBUTION OF THIS DOCUMENT IS UNLIMITED,,
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VOLUME 1 TABLE OF CONTENTS
Sect ion 1 .O Background
1.1 S t a r t i n g Point f o r the Study 1.2 1 . 3
In tegra ted Approach I
Study P a r t i c i p a n t s 2.0 Study Scope 3.0 Technical Report: Volume I1 .Synopsis 4.0 Engineering Approach t o the Advanced Power Train
4.1 Study Methodology 4.2 Sys tem Analysis
4.2.1 S tudies o f Early Comercial P lan ts 4.2.2 Studies o f In tegra ted Facilities for MHD Program Options
4.3 MHD Generator 4.4 Combustor 4.5 Diffuser 4.6 Power Conditioning 4.7 Scal ing Considerations 4.8 Requirements f o r Coal 4.9 R e l i a b i l i t y and Lifetime 4.10 Other Components and Subsystems
5.1
5.2 The Poten t ia l of MHD/Steam Power Plan ts Justifies the National
5.3
5.0 Resul t s and Concl usi ons The Power Train Development Program Plan has been Delineated: The Objective of the Contract has been Achieved
Program The Technological Base for the Program has been Demonstrated
5.4 Technical Success i n the Shor t e s t Schedule and a t Lowest Cost
5.5 will be Realized through an Integrated Development Program The Management and Engineering Tools, Expertise and Concepts t o Carry O u t the Program t o a Successful Conclusion have been J u s t i f i e d
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Page 1-1 1-2 1-2 1-4 2-1 3-1 4-1 4-1 4-3 4-4 4-8 4-8 4-10 4-12 4-1 3 4-14 4-14 4-16 4-18 5-1 5-1
5-6
5-9 5-1 5
5-17
VOLUME 1 LIST OF FIGURES
Figure No. T i t l e
2 3
4 5 6 7 8 9
10 11 12 1 3 14
5
MHD Power Train i n Relation t o Total MHD/Steam Power P1 a n t C1 a s s i c a l Sys tems Enpi neeri ng Approach The Advanced Power Train i s Par t of an Overall Systems Def in i t ion Tree. Elements o f the APT System a r e Shown. Westinghouse Analytical Program Hand1 ing Systems 500 MWe MHD/Steam P lan t Arrangement MHD Channel Concept Combustor Concept Diffuser Concept Power Conditioning Concepts, Schematic Power Train Program Schedule Effect of .Rating on Rela t ive Cost o f E1ectricit.y Effect o f Rating on Performance MHD Program Phases Work Breakdown S t r u c t u r e First and Second Level
LIST OF TABLES Sumnary o f Reference MHD/Steam P1 a n t Descriptions In t eg ra t ed Facil i t ies Current S t a t u s o f MHD R e l i a b i l i t y / D u r a b i l i t y Coal F i red Power Train w i t h Power Conditioninq Scal e-Up Considerations Power Train Program Cost Estimate - by Object ive
Page No.
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1-3 4-1
4-3 4-7 4-11 4-12 4-1 3 4-15 5-4 5-8 5-8 5-10 5-16
4-5 4-9 4-17 5-3
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ABSTRACT
The objective of the MHD Advanced Power Train Project, Phase I, is to def.ine a Plan for the Development program that will 'I.. . provide qualification of the engineering data base required for the design, fabrication and operation of MHO Power Trains for MHD/steam plants with an - 200 MWe capacity". The project objective has been achieved. A program has been defined that addresses: rugged, reliable and cost effective equipment required in the electric utility application, b) the scale-up, in reasonable steps in both performance and life- time, of the power train components to reach the - 200 MWe plant capacity goals, c) the integration of the components into proof-of-concept power train systems at two logical ratings, and d) the integration of the power train sys- tem into the total plant at the larger of the two ratings.
a) the engineering.development of components prototypical of the
The development program has been justified. the benefits of MHD/steam plants including cleaner air, insured supply of
energy resources, reduced oil imports, reduced demand for cooling water and new plant sites, and reduced creep of electric power cost. Beneficial and cost effective power train and MHD/steam plant performance and cost goals have been defined. The development program requirements are established and the plan will be implemented consistent with the goals.
The U.S. citizenry will realize
The technological base for the program has been demonstrated. The remaining system and plant proof-of-concept steps, and cost development scale-up in performance and lifetime, nology and there is no requirement for scientific sion was confirmed in detailed program reviews by supplier and utility advisors.
reduction are engineering extensions of existing tech- breakthrough. This conclu- panels of senior equipment
The Plan is an integrated program that will produce technical success in the shortest schedule and at lowest cost. The plan includes the technical integra- tion necessary to focus the component development efforts into a cohesive power
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-train technology. It recognizes and pr.ovides For the design and development of the MHD Generator (the channel, magnet and power conditioning) as a closely integrated unit so that opportunities for overall generator optimization will be realized. effort, for coordination of the development program efforts with the testing facilities.
The plan also identifies the need, and provides appropriate
The plan identifies the management and engineering tools and expertise required for the cost effective technical integration and implementation o f the develop"- ment program. Typical examples of management techniques include: appropriate application of the System Engineering Approach, document control with a formal document change control procedure, regular progress reviews with subsequent variance reporting to focus management and DOE attention on critical issues. Typical examples of engineering tools include: computer aided design (CAD) for rapid technical communication and cost reduction through elimination of expen- sive models, and the Westinghouse SPA/SUMMARY computer model for prompt evalua- tion of effects of suggested development actions on total power train and MHD/steam plant performance and/or economics.
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1 .O BACKGROUND
The successful development and application of magnetohydrodynamic (MHD) elec- tric power generation technology would make a- significant contribution toward meeting the national energy requirements. the direct combustion of coal, the nation's abundant fossil energy resource.
MHD/steam plants would be fueled by
4
Numerous studies have confirmed that MHD/steam plants have the potential to be economically competitive and to produce up to 50 percent more electricity per ton of coal consumed compared to the conventional coal/steam plant. This auto- matically reduces the ecological impact of coal mining and transportation. MHD plants will also significantly ameliorate environmental concerns, including waste heat and oxides of sulfur, nitrogen and carbon.
The study reported here deals with the key enabling technology for the con- struction of such plants, the MHD power train, see Figure 1. The major compo- nents of the power train are: the coal combustor, the MHD generator, the diffuser, and the power train controls. The MHD generator, analagous to gas turbine-generators, consists o f the channel, power conditioning and the magnet (the magnet was excluded from the contract work scope).
Figure 1. MHD Power Train in Relation to Total MHD/Steam Power Plant
c 'Particular emphasis in this study was placed on concepts that offer potential as early commercial plants, on the requirements for the power trains for such plants, and on the engineering development and proof-of-concept testing requirements for these power trains.
1.1 STARTING POINT FOR THE STUDY
The Government. carried out an electric power
primarily through the Department of Energy, and industry, have extensive effort to. design and develop MHD/steam combined cyclg plants. Significant progress has been achieved in several
component and subsystem areas. has been demonstrated by TRW. test at the Component Development and Integration Facility (CDIF). capped copper anodes, for the MHD generator, have been operated for 1300 hours at the AVCo Everett Research Laboratory. operated at 6 Tesla at the Argonne National Laboratory. Demonstration Experiment at the U. S. Air Force Arnold Engineering Development Center has produced an enthalpy extraction of about 12 percent at a magnet field strength of 3.9 Tesla and a power output o f 36 mW. power to ac electric power for the Montana Power Co. system has been demonstra- ted with Westinghouse designed and constructed hardware at the CDIF. Seed deposition and collection tests, as well as experiments to demonstrate low emission of oxides of sulfur and nitrogen have been performed at the University of Tennessee Space Institute.
A 20 HWt combustor with high slag rejection The first stage o f a 50 MWt combustor i s under
Platinum
A superconducting magnet has been The High Performance
Inversion o f dc MHO
Supported by numerous other analytical and experimental activities, the feasi- bility of the MHD concept for power generation has been established. Extensive preliminary engineering or technology base experience has been gained for indi- vidual components at small scale (up to 50 MWt thermal), and partial "bread- board" systems have been successfully operated.
1.2 INTEGRATED APPROACH
This component by component development is impressive, but it is not adequate for the scale-up of the MHD power train and its components. This requires
1-2
c ' d i r e c t i o n t h a t can only be provided .by def in ing power t r a i n requirements d i r e c t l y r e l a t ed t o commercially v i ab le t o t a l p l an t requirements. A proven method t o provide such power t r a i n requirements i s t h e System Engineering Approach (SEA).
SEA i s sometimes ca l l ed t h e Vop-down1I approach. t r a t e d i n Figure 2 w i t h re fe rence t o t h e power t r a i n subsystem. The u t i l i t y needs def ine the u l t imate use and from this s tar t ing po in t requirements t i e r down f o r t he p l a n t , the e a r l y commercial power t r a i n , t h e advanced power trgin ( A P T ) , and f i n a l l y , t h e system and equipment spec i f i ca t ions . plementary requirements d u r i n g the top-down requirements d e f i n i t i o n a r e indica- ted on t h e r i g h t of the f igu re . The in f luence indicated by "Design GuidelinesU pervades the e n t i r e process and r e f e r s t o the d i s c i p l i n a r y requirements and procedures which a r e a t the h e a r t of the systems approach t o p r a c t i c a l equip- ment design.
I t s e a r l y s t a g e s a r e illus-
Sources of sup-
(UTILITY NEEDS I n c L m i n t RATING, REOUIRMNTS LIFETIME, AVAIL- ABILITY; M I N AlN- AEILITYI COST3
POWER TRAIN (INTERFACE REOUIRWENTS) REOUIRWENTS
?RELlMNARY EPUlPnENT SPEClFICATlOnS DESIGN
@ STATE OF TECmOLOGY, IKIERFACE REOUIRMEHTS, CODES AND STbNOARDS, QUALITY ASSURANCE, RELIABILlTYr M I W T A I M l I L I T Y r LIFETIHE, I U T ~ l A L . 5 SUITABILITY
Figure 2. Class i ca l Systems Engineering Approach
T A S K 1
TASKP
TAsu m
' The three tasks of the contract s tudy reportedcherein (Phase I ) a r e enclosed i n the dot-dash l ines . design and fabricat ion of APT t e s t hardware, construction of the APT, t e s t operation of power t r a i n s , and data reduction and analysis t o es tab l i sh the Engineering Data Bases. the ear ly comnercial power t r a i n and f u l l comnercial plant requirements.
Act ivi t ies which would show up below the f igure a r e the
The resu l t s then would logical ly feed back t o ref -L
1 .,3 STUDY PARTICIPANTS
This System Engineering Approach has been applied by a Westinghouse l e d team including Applied Energetics, Burns & Roe, HMJ Corp, SEITEC, and TRW. U t i l i t y Advisory Council was convened t o review the to t a l power plant require- ments, the Council included representatives from Boston Edison, Duke Power Co., Montana Power Co., Nevada Power Co., Northeast U t i l i t i e s , Penn. Power & L i g h t , Pub. Service Electr ic & Gas Co., Southern California Edison Co., Southern Services, and TVA.
A
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2.0 STUDY SCOPE
The Phase 1 cont rac t study purpose i s the " . . .Def in i t ion o f a Development Program f o r a MHO Advanced Power T ra in (APT)." The work scope i s made up o f th ree tasks, as f o l l o w s :
Task I
Task I1
Task I11
Analysis o f MHD Steam Power Plants, Determination o f MHD *
Performance requirements and Design C r i t e r i a , and C r i t i c a l Evaluat ion o f the State o f Technology
D e f i n i t i o n o f MHO Power T ra in Oesign Approaches
D e f i n i t i o n o f a Program Plan f o r MHD Advanced Power Tra in Development
The Task I e f f o r t i s d iv ided . in to th ree subtasks:
0
0
0
Analysis o f MHD/Steam Power Plants and Power T ra in Requirements . Scal ing Relat ionships and APT Performance (Test ing) Requirements . C r i t i c a l Evaluat ion o f State o f Technology.
The Task I1 e f f o r t i s d iv ided i n t o th ree subtasks:
0
0
0
Deta i led MHD Generator Studies f o r a Plant o f 200 HWe Capacity.
I d e n t i f i c a t i o n and Assessment o f Power Tra in Design Approaches.
Pre l iminary Conceptual Design Study o f the Preferred Power Tra in f o r a P lan t o f 200 MWe Capacity.
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3.0 TECHNICAL REPORT: VOLUME I I SYNOPSIS
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3.0 TECHNICAL REPORT: V ~ L U M E 11 SYNOPSIS
The Phase I study results are reported i n six volumes in addition to'this -Executive Sumary as follows:
Volume
2
3
4
5
6
7
Title
MHD/APT Development Program Plan
APT System Description and Specification for 200MWe Plant
Power Train Design Approaches and Detailed MHO Generator Studies
Plant Analyses, Scaling Studies, Technology Assessment, Testing Requirements, and Competitive MHD/Steam Plant Requirements
Special Studies - Evaluation of MHD Program Options
Appendices
Content
Describes the recommended PT engineering development and test effort to be implemented in Phase 11. Provides a suggested Work Breakdown Structure, task descriptions, schedule, management plan and cost estimate. (Task I11 results.)
Provides the format and currently available definitive data with emphasis on the PT and component interface. (Task 11, subtask 3 results.)
Describes innovative approaches and concepts devised to guide the Development Program Planning effort (Task 11, subtasks 1 and 2 results.)
Describes the analyses and related efforts that form the bases for the Development Program Planning (Task I results. )
Describes studies of 50 and 80 HWt and Frank E. Bird Retrofit integrated facility conceptual designs. (Added task results.)
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HEAT AND SEED RECOVERY
4.0 ENGINEERING APPROACH TO THE ADVANCED POWER TRAIN
BALANCE of
C L A N 1
STEAM OXIDIZER TURBINE- MHD
POWER TRAIN MAONET SYSTEM GENERATOR
PLANT
4.1 STUDY METHODOLOGY
NOZZLE CONGOLIDATION COMBUSTOR AND AND
CHANNEL INVERTER -
The MHO power train subsystem is one of several major subsystems that comprise
DIFFUSER
a MHD/steam power plant. It is distinguished from the others by the prepon- derance o f new technology required for its components. Its integration with other subsystems must be taken into account in the technology development to
..
ensure that an efficient and cost-effective power plant results. ing APT design and development requirements, the integrated system needs must be satisfied.
In establish-
The APT and APT program can be displayed as part of a systems definition tree shown in Figure 3. In the figure, the tree has been extended to define the major components of the MHO power train subsystem, as defined in the contract work scope.
MHD POWER PLANT iF REGENERATION LlJ
Figure 3. The Advanced Power Traln i s Part of an Overall Systems Definition Tree. Elements of the APT System are Shown.
' In the first step of the study, MHD/steam plan& were conceptually designed and their competitive potential was established in a comparison with a modern conventional coal/steam power plant. where specific design, rating, lifetime and cost goals and requirements were established for the MHD power train and its individual components.
The designs were carried to the point
These MHD/steam power plant designs also produced design, rating, lifetime and cost goals for all of the other power plant subsystems. tnformation for other MHD subsystem development work.
This provides useful .-
In the second step, methods were defined to relate engineering data over the range from small test facility to commercial plant sizes. These methods can be thought of as the I'pathwaysll along which the technology must be developed and demonstrated as the commercialization of MHD is realized. The scaling rela- tionships are speclfic to components (and even to subcomponents) of the MHD power train.
In the third step, the existing state-of-technology was explored through literature search and visits to several U. S. development centers active in the national MHD program. The results were correlated with the scaling relation- ships. realized in the commercialization of the power train and its components.
An assessment was made of the testing requirements remaining to be
In the fourth step, the MHD generator (including the channel, power condition- ing subsystem and the magnet) was studied in some detail. Concepts of innova- tive components were devised to indicate development directions to produce the engineering data base for rugged, reliable and cost effective MHD generators.
In the fifth step, the subsystems and components of the power train (indi- vidually and collectively) were studied to identify and recommend design approaches to be considered in the Development Program Plan.
In the sixth step, a MHD/APT System Description and Specification was prepared. Particular attention was given to definition of the Specification format to make it of continuing value throughout the Phase I 1 development
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' effort and future design phases. Special aGention was focused on the detailed definition of interfaces (and interactions) between components within the Power Train and between the Power Train and the balance of plant.
In the seventh and final step of the reported effort, the detailed Development Program Plan was prepared. "...provide qualification of the engineering data base required for the design, fabrication and operation of MHD Power Trains for MHD/steam plants with an 200 MWe capacity . II
The Program Plan scope was delineated to
.*
Thus, it can be seen that the contract study is a partial progression through the steps of the classical Systems Engineering Approach (SEA). This is a successful approach that has been evolved from many utility, aerospace and military projects. If the MHO program is to be successful in the current era of restricted development program funding, it must be focused. SEA is an excellent way to provide that focus.
4.2 SYSTEM ANALYSIS
To define efficient and cost-effective MHD/steam power plant designs an extensive study was carried out using the total plant design code displayed in Figure 4. The Westinghouse System Performance Analysis (SPA/SUMARY) code provided the capability to perform design optimization studies for each design change, including cost trade-offs.
?ERFMYINCE
MYLlCAL DATA
Figure 4. Westinghouse Analytical Program Handling Systems
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.The SPA code accepts fuel data compiled by the’NASA TRANS 72 code. I n the SPA code, a gorithms of up t o 100 integrated plant elements can be analyzed simul- taneous y. The SUMARY code accepts the SPA output and presents tabulated data on perf rmance, cos t and physical features . Data f o r the t o t a l plant and a l so each component a re presented. The cost data a r e a l so presented i n t h e Uniform System of Accounts format, showing: component cos t , balance of plant cost , i n s t a l l a t ion cost , ind i rec ts , and contingency. Cost of e l e c t r i c i t y i s a l so computed and displayed.
4.2.1 STUDIES OF EARLY COMMERCIAL PLANTS
Making use of previous DOE/NASA studies as a s t a r t i n g point, ten careful ly selected MHWsteam power plant basic configurational arrangements o r s i z e var ia t ions were considered in-depth. Each of these ten cases was examined parametrically w i t h respect t o MHD cycle pressure ra t io , enrichment of combus- t ion a i r above the natural 21% oxygen content, and MHD generator loading fac tor . The analyses were based on the use of Montana Rosebud coal and steam (bottoming) cycle conditions of 2400 psi/lOOO°F i n i t i a l l y w i t h reheat t o 1000°F.
Based on (1) efficiency (resource parameter), (2) cost o f energy ( u t i l i t y worth parameter) and (3) s i t e a b i l i t y (environmental parameter), three a t t r a c t i v e reference ear ly commercial MHD/steam power plant designs were defined from among the variations studied. comercial plant rating: a r e described i n Table 1 . a supersonic channel i s a l so shown.
The reference designs cover a range of potential 200 MW,, 500 MWe, and 1000 MW,. These designs
A fourth case, a 200 MWe plant based on the use of
A p lo t plan of the 500 MWe plant i s shown i n Figure 5. 1000 MWe plants have s imi la r arrangements.
The 200 MWe and
The major c r i t e r ion f o r es tabl ishing the Figure 5 plant arrangement was t o achieve m i n i m u m cos t of e l e c t r i c i t y while sa t i s fy ing the pract ical constraints associated w i t h construction, maintenance, operation, and safety.
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TABLE 1 SUMMARY OF REFERENCE MHD/STEAM PLANT DESCRIPTIONS
Plant Data Coal Thermal Input, MWt Net Power Output, MWe P lant Ef f ic iency, 4: Plant Capi ta l Cost, $M Cost o f E l e c t r i c i t y , M/kWh
Selected Component Data
P I Oxygen Content i n Combustion A i r , X Preheat Temp, O K
Combustor E x l t Pressure, A t m
v1
Slag Removal, X MHD Channel Dimensions, M - I n l e t - Out le t - Length MHD Enthalpy Extract ion, X Mach. No. Number o f Electrode Pairs Number o f dc/ac Inve r te rs Magnet F i e l d Strength, Tesla
- 1000
2278 989
43.4 7 60
62.6
36 922
7.3 85
0.97 x 0.97 2.50 x 2.50
15.9 21.7 0.875
1060 5 6
- 500
1163 49 5
42.6 449
70.5
36 922
6.2 85
0.77 x 0.77 1.79 x 1.79
11.7 19.6 0.875
782 3
6
- 200
483 195 40.4
236 88.8
36 922
4.8 85
0.54 x 0.54 1 . 1 8 , ~ 1.18
10.6 16.8 0.875
71 0 2 6
200 (Supersonic)
483 193 40.5
234 90.5
36 922
4.9 85
0.56 x 0.56 1.13 x 1.13
9.5 15.5
1.3 - 1.0 557
2
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= A major consideration i n establishing the planearrangement was the cos t of piping, ducting, and wiring. Both operating (power loss) cos t and capi ta l cost impacts of the piping, ducting, and wiring were considered i n a r r iv ing a t the preferred plant arrangement.
The concept consis ts of careful ly integrated MHD topping cycle and bottoming steam cycle. The optimum net e lec t r ica power from the MHD portion is s l i g h t l y less than half the t o t a l plant output. T h i s requires t h a t the MHD generator ex t rac t 16 t o 22 percent of the t o t a l p an t heat i n p u t i n the form of e l ec t r i c - power.
To provide s t ruc tura l v i ab i l i t y , the MHD power t r a i n operates w i t h water-cooled and s lag coated ncoldn walls. t i a l , being on the order of 20 percent of the t o t a l plant i n p u t . Proper integrat ion of this heat in to the bottoming steam cycle i s an important face t of plant efficiency. A t o t a l p l a n t design codep such as SPA/SUMARY, i s an e f f i c i e n t tool f o r the study and design of such plant interfaces .
The heat rejected t o th i s cooling i s substan-
The MHD process requires a plasma (gas stream) w i t h an e l ec t r i ca l conductivity of 6 mhoheter o r better. require a h i g h degree of preheat t ha t i s impractical w i t h current technology. For ear ly commercial plants the desired e l ec t r i ca l conductivity can b e produced by oxygen enrichment of the a i r and th i s approach is u t i l i z e d i n a l l p lants considered i n t h i s study.
Combustion of coal w i t h atmospheric a i r would
While this study i s concentrated on the power t r a i n components, see Figure 3, i t i s important t h a t the other components necessary t o accomplish the t o t a l plant function be carefu l ly integrated in to the design. These include: the oxygen plant f o r enrichment of the combustion a i r , I1seed1l recovery and reprocessing, heat recovery subsystems, instrumentation and control subsystems, and magnet system. The study resu l t s c lear ly demonstrate t h a t the m i n i m u m cost of energy i s achieved by optimizing the to t a l plant , resul t ing i n a power t r a i n t h a t i s s ign i f icant ly off-optimum on a component by component basis .
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B
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' 4.2 .2 STUDIES OF INTEGRATED FACILITIES FOR MH6 PROGRAM OPTIONS
An additional subtask was assigned to the project. 50 MWt, 80 MWt and possible retrofit facilities. system performance, captial costs, construction schedules, resource require- ments and technical risk.
The study was to assess The study was to evaluate
The 50 and 80 MWt integrated facilities were studied based on their installa- tion at the CDIF. selected as the candidate retrofit unit.
The Fank E. Bird unit, owned by Montana Power Company, was -
These studies utilized the SPA/SUMARY code package. assessment were based on data obtained from candidate component suppliers.
The cost data and schedule
Sumnary results, for the four cases analyzed, are shown in Table 2. The 50 MWe and the 40 MUe retrofit cases both assume use of the Fank E. Bird Unit. steam and electric drive for the combustor oxidant compressor.
The difference in MHD generator size arises from consideration of both
4.3 MHD GENERATOR
The MHD generator concept used herein employs a linear channel, see Figure 6. The channel concept has platinum capped (at least in the higher power sections) copper electrodes and segmented copper sidewall bars, maintained at low (cold wall) temperature, operated in a fully slagged condition, Faraday loaded and supported in fiberglass box walls. The walls require external strengthening members to allow a relatively thin fiberglass wall and to make maximum use o f the magnet warm bore. to be developed to be as economical of warm bore space as possible, and these must also be engineered for high reliability and long duration operation. electrical power has to be removed through a power conditioning system (power management plus inverters). Sidewall potential distribution is fixed through conducting but interrupted sidebars placed along essentially equipotential lines between anode and cathode. It will be designed with modern solid-state
The electrical and cooling fluid arrangements have also
The
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TABLE 2 INTEGRATED FACIL IT I ES
Item 50MWt 80MWt 40MWt 50NWt
Location
Compressor Drive
Thermal Input, MWt 50 80 276 31 6
Net Electric Power, MWt 13.5 23.2 89 106
112 Capital Cost, $ Million 138 283 31 9
Constr. Schedule, Months 63 63 57 57
Cost o f consumables, $/hr. <288 (Coal and seed)
<441
Value o f power, $/hr. 67 5 1160
Risk (Based on immediate start)
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'power electronic components to reduce, to the minimum practical extent, the losses in the subsystem. current distribution over the anode surface and to limit fault currents. This is an important objective because the major electrode life limiting mechanism is erosion due to high local current density. The consolidated dc power will be conditioned for the electric utility grid in multiple inverters. generator will utilize a 6 Tesla (peak magnetic flux) superconducting magnet. A control system will insure proper operation of the generator (and the rest of the plant) under all conditions over the power range from at least 75 to 100 percent power. It must also handle normal start-up, network transients, and both normal and emergency shutdown situations.
It will be designed to assist in establishing uniform
The MHO
The engineering development of such a MHD generator is judged to require an extensive and focused program. The channel must be designed and developed, in all aspects, to have a minimum life of six months in early plants and at least one year in later plants. To meet this goal, the designers must have detailed engineering data and information in all of the detailed areas of design. combined design of the nozzle, channel (with wiring and cooling arrangements), magnet and diffuser must provide for rapid removal, replacement, reconnection and checkout of the channel.
The
4.4 COMBUSTOR
The combustor concept used in the study, see Figure 7, is the two-stage slag- ging combustor under development by TRW. 20 MWt sizes have been built and tested successfully for operation and per- formance. train testing. Performance prediction methodology check experimental results at the 10 MWt and 20 MWt sizes. has been produced and is being tested.
Combustors of the 10 MWt and
The 20 MWt size has also been used in limited successful power
The slagging stage of a 50 MWt combustor
4-10.
f
I
,ING AIR
CABLE
ELECTRODE COOLING WATER CONNECTION \ COOLING WATER MANIFOLD-I (ELECTRODE)
Figure 6 . MHD Channel Concept
c
SECOND STAGE OXIDANT INJECTORS
Figure 7. Combustor Concept
The major development areas are: slag removal systems, electrical isolation and support structures, seed injection system to ensure uniform plasma conduc- tivity, and engineering impacts due to scale-up from the existing 20 HWt size. tests and in existing or anticipated facilities. tests are recommended at 50 MWt and component tests are recommended at 100 MWt, or above. mance can be achieved at large power levels.
Many of the tests to provide these data can be obtained in stand-alone Both performance and lifetime
It must be proved experimentally that adequate perfor-
4.5 DIFFUSER
The diffuser concept, see Figure 8, employs a constant area section followed by a subsonic diffuser section. plate (slag baffle) in a dump tank. The key concerns are the selection of a unit that interfaces properly with the MHO channel (Mach No.) , provides ade- quate (at least 0.5) pressure recovery factor, and interfaces properl’y with the heat recovery equipment.
This subsonic section is followed by a blast
Cold flow modeling can be an effective and economic
4-1 2
1
t o o l and an extensive t e s t s e r i e s i s . a n t i c i G t e d . Hot f l o w performance evaluat ion and comparisons can be ca r r i ed o u t i n small (20 mW thermal) power t r a i n s and i n conjunct ion w i t h other t e s t programs.
CONSTANT AREA DUMP TANK CHANNEL
c FROM CHANNEL
Figure 8. D i f f u s e r Concept
4.6 POWER CONDITIONING
The MHD power condi t ion ing subsystem, see Figure 9, consists o f a power manage- ment subsystem (Figure 9b), which consolidates the hundreds o f i n d i v i d u a l channel e lectrode outputs, and then bulk invers ion (Figure sa) t o u t i l i t y q u a l i t y 60 Hertz output. To date, t he consol idat ion and c o n t r o l f unc t i on has been accomplished w i t h resistance networks. These have been adequate f o r experimentation w i t h small channels. More e f f i c i e n t elements f o r consol idat ion and con t ro l are feas ib le w i t h today's state-of-the-art i n power e lect ron ics.
Power con t ro l (power management) concepts t o l i m i t i n t e r n a l channel f a u l t power and maintain current d i s t r i b u t i o n over the electrodes appear t o o f f e r p o t e n t i a l
' f o r achieving the f u l l design endurance ( l l fe)&of the channel. The engineering development should include analytical e f f o r t s , breadboard t e s t s and integrated demonstration. Bulk inversion of the consolidated power from dc t o u t i l i t y qua l i ty ac I s well established engineering as exemplified by HVDC i n s t a l l a - t ions. Westinghouse under EPRI contract . expected t o be operated in to multiple dc/ac inverters . Sat isfactory operation and appropriate control should be demonstrated w i t h actual MHD generators. I t i s recommended t h a t a l l future MHD generator development and t e s t ing be con- ducted w i t h act ive power management subsystems. Inversion t o the ac u t i l i t y g r i d i s desirable.
Application t o MHD has been demonstrated by the CDIF inver te r , b u i l t by Large e l e c t r i c u t i l i t y MHD generators a re
4.7 SCALING CONSIDERATIONS
Power t r a i n , and even component, t e s t s t o define and confirm the engineering data f o r commercial MHD plants a r e very cost ly . Hence, i t i s desirable t o conduct such t e s t s a t the smallest ra t ing t h a t w i l l produce the necessary resu l t s . Scaling relationships and the SPA code were used t o explore the usefulness of t e s t s a t 20, 50, and 100 MWt ra t ings. Many MHD power t r a i n development concerns can be resolved a t 50 MWt. resolved a t 100 MWt except t ha t demonstration of adequate values of key performance related parameters such as enthalpy extraction ( the r a t i o of generated e l ec t r i c power t o fuel i n p u t ) require t e s t s a t 250 MWt level o r more.
Almost a l l concerns can be
4.8 REQUIREMENTS FOR COAL
A good understanding of the interact ions of coal slag w i t h the e l ec t r i ca l and mechanical aspects of MHD generators appears v i t a l f o r successful power t r a i n design. T h i s i s so f o r achievement of both high performance and long l i fe t ime.
To date very l i t t l e MHD operation w i t h coal has been accomplished. Most opera- t ion has been w i t h a simulation of coal burn ing u s i n g a l i q u i d fuel such a s toluene w i t h the introduction of simulated coal s lag using ash.
-
4-14
c
. Entry Power Generating. Exit I Region I Region
~. I I I I
I
I -
I I I 1- I
! 1
El Inverter
Consolidation Connecting . Network (part of the Power Management .@hyfteml
9a. Inverter Connection - 5 Unit Example DERIVATIOK CONTINUED
EACH PHASE CAN HANDLE 6EVERM ELECTRWEI BY USING PARALLEL CONNECTED CONVERTERS
9b. I
Principle of Power Management
Figure 9. Power Conditioning Concepts, Schematic
- .
0093Tz25-23 4-15
c ‘Coal burned in a slagging coal combustor should be standard in all MHD power train or generator tests. to do this and other combustors should only be used in special circumstances (e.g., short duration testing).
The major U. S. MHD laboratories should be equipped
4.9 RELIABILITY AND LIFETIME
Most MHD hardware built to date has been for the purposes o f experimenting with one or more detail aspects of MHD technology. mostly adequate for the intended test purposes has not been engineered or manu- factured to commercial quality assurance standards. reality, hardware (along with auxiliaries) of good overall quality must be evident. mation is the Engineering Development phase of a new technology program. now time to embark on this engineering development effort. ing hardware, so designed and qualified, is a vital part o f the effort.
As such, the equipment, while
To move MHD to commercial
The preparation o f the engineering and manufacturing data and infor-
Building and test- It is
Channel lifetime, between refurbishments, is a key element in utility accep- tance. The maximum acceptable replacement frequency is twice per year, timed to match the usual Spring and Autumn low utility demand periods. This, along with other consistent criteria, was taken as the basis for the study leading to the findings shown in Table 3.
Life testing pertinent to the subcomponent level for some components can be performed in rig testing. Examples include: elastomer seals, plastic electric isolation components, and the fiberglass box wall elements. must be planned to take maximum advantage of the smallest feasible test facil- ities to minimize the cost of the Engineering Development phase.
All life testing
Readiness to design and construct viable comnercial MHD/Steam power plants must incorporate adequate technology for all of the plant components. Therefore, it will be necessary to carry out development programs on other components, in addition to those included in the Advanced Power Train.
4-16
TABLE 3 CURRENT STATUS OF MHD RELIABILITY/DURABILITY
CDIF 38 POWER TRAIN SPEC5-97
PROPOSED COMMERCIAL PLANT, FORCED OUTAGE MTBF
(HOURS)
DURABILITY WITHOUT "RELEVANT" FA1 LURE
(HOURS) TEST STATUS
(HOURS)
I 885-95 0 COMBUSTOR 2000 16,667
0 GENERATOR TBD <loo0 8,000
NOZZLE CHANNEL ANODES BALANCE DIFFUSER
TBD TBD 2000 TBD TBD 2 0 0 0
100,000 9,524
18,182 20,000
100,000 TB D TBD
0 POWER CONDITIONING TBD <loo0 40,000
POWER TAKEOFF INVERTER
TBD TBD
2000 2 0 0 0
* 80,000 80,000
0 BALANCE MHD SYSTEM
0 OVERALL MHD SYSTEM
TBD TBD 33,333
TBD G O O 4,000
i
=4.10 OTHER COMPONENTS AND SUBSYSTEHS c
The magnet technology is well advanced and continues to be improved as a spinoff from other programs such as fusion. cost item and effort should be devoted to engineering studies that correlate the magnet/channel interface to the improvement of both.
However, the magnet is a major
The heat recovery boiler will require extensive development, including testing at 20 HWt and larger rating, prior to commercial plant commitment. .-
Seed recovery, from slag and spent combustion gas will require extensive development. Seed regeneration RbD is indicated, starting with comparative assessment of the formate process against alternatives. experimental data on dust collectlon in MHD systems must be rectified.
The low level of
The total environmental impact of MHD systems needs to be examined. The results obtained in this study, and corroborated by others, indicate that MHD systems can make a significant contribution to the reduction of oxides of sulfur and nitrogen in the electric power generation process. Other aspects, such as particulates and solid wastes, should be examined.
Finally, engineering study of total MHD/steam power plant instrumentation and control is indicated. In any planned or inadvertent off-design operation of the power train, the interactions with the bottoming steam plant and the utility grid are likely to be significant. Start-up and shutdown transients, in a closely integrated MHD/steam plant must be examined. the ac grid, is more complex than normal because o f the two different sources of electric power.
Plant trip-off, from
4- 18-
L
c E
5.0 RESULTS AND CONCLUSIONS
The results achieved in Phase I of the MHD Advanced Power Train Program can.be summarized under five major conclusions:
5.1 - The Power Train Development Program Plan has been Delineated: The '4
Objective of the Contract has been Achieved,
5.2 - The Potential of MHD/steam Power Plants justifies the National Program,
5.3 - The Technological Base for the Program has been Demonstrated,
5.4 - Technical Success in the Shortest Schedule and at Lowest Cost will be Realized through an Integrated Development Program, and
5.5 - The Management and Engineering Tools, Expertise and Concepts to Carry the Program to a Successful Conclusion have been Identified.
5.1 THE POWER TRAIN DEVELOPMENT PROGRAM PLAN HAS BEEN DELINEATED: THE OBJECTIVE OF THE CONTRACT HAS BEEN ACHIEVED
The MHD/APT project is unique in that it addresses, for the first time, the complete program to carry one of the MHD systems through all the myriad development steps remaining to be accomplished before the utilities can apply MHD/steam power plants with confidence. contributions to the understanding of the design of the MHD generator as an integrated subsystem.
The project has also made unique
The plan for a development program that will produce the engineering data base for the design of competitive early commercial power trains has been delinea- ted. the information to be provided by execution of the plan has been
Direct correlation between the requirements for the commercial plants and
5-1
'established. accepted design limits and parameters were used as the s t a r t i ng point f o r the development program. A conscious decision was taken t o preclude any assumption of new science o r ''breakthrough" i n the program. The program i s concentrated on the engineering development of components from the presently defined labora- t o r y and breadboard devices t o prototypes of the rugged, r e l i ab le and low cost equipment t h a t will be necessary i n the commercial e l e c t r i c u t i l i t y plants . The present low level of both performance an.d l i fe t ime demonstration was recog- nized and the plan includes power t r a i n t e s t s a t two ratings w i t h progressive '+
The present state-of-technology wzs assessed and generally
l i fe t ime increases and cost reduction goals t o minimize the risk associated w i t h the scale-up r a t io s . compared t o the present s ta tus on the one hand and t o the required s t a tus f o r the ear ly commercial plant on the other hand a r e shown i n Table 4 . The f i r s t s tep provides the integrat ion of the power t r a i n system. provides the opportunity t o carry o u t t o t a l plant integration, assuming t h a t the development and integration of other developmental systems (heat recovery/ seed recovery and seed regeneration) a r e carr ied out on the appropriate schedule -- an assumption tha t i s considered reasonable by experts i n those f i e l d s .
The choice of ra t ings f o r the two development s teps ,
The second s tep
In the area of the MHO generator (channel, magnet and power conditioning) new design approaches have been ident i f ied , and their development planned, t h a t have the potential t o contribute s ignif icant ly: a ) Toward making f u l l use of the generally accepted l imits on channel design and operating parameters, b )
Toward real iz ing the f u l l theoret ical channel l i fe t ime, c ) Toward a power t r a i n control system w i t h the f l e x i b i l i t y f o r easy plant operation, and d ) Toward real izat ion of a channel w i t h low production cost and h i g h r e l i a b i l i t y .
5-2-
I 1428
TABLE 4 COAL FIRED POWER TRAIN WITH POWER CONDITIONING SCALE-UP CONSIDERATIONS
PLANT INTEGRATION (RETROFIT)
COMMERCIAL PLANT
STATUS ENGINEERING DEVELOPMENT
PERFORMANCE MW(t) 20 - 50* 50 150-250 . 500
2* 2 - 3.5 15 - 35 70
LIFETIME, HOURS POWER TRAIN ELECTRODES
FEW 1500*
500 2000 4000 - 8000
2500 COST (Channel)
$/kW(e) 405 40
*SIMULATED COAL
707075-17A
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RETROFIT POWER TRAIN TEST OPERATION/DATA ANAL.
0 CONSTR./I NSTAL L/CH ECK-OUT DESIGN - TITLE I & II
0 GOALWBASELINE DESIGN/ PLANT STUDIES
50 MW(T) POWER TRAIN 0 500 HR ENDURANCE TEST 0 CHANNEL DES., FAB., INSTALL 0 POWER MANAGEMENT DEV. 0 COMBUSTOR DEW. & TEST 0 DIFFUSER DEV.
MHD GENERATOR DEVELOPMEN? 0 HIGH INTERACTION &
POWER EXPERIMENT 0 DEV. GENERATOR TESTS 0 DEV. CHANNEL PRODUCTION e MATERIAL & STRUCT. DEV.
707075-10A
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6 7 8 9 10 11
PLANT ENGINEERING DATA BASE
MHD GENERATOR ENGINEERING 4
i
Figure 10. Power Train Program Schedule
I
= The plan recognizes the need f o r continued ap"p1ication o f the System Engineer- i n g Approach t o provide the management and technica l i n t e g r a t i o n o f t he development and t e s t i n g e f f o r t s o f many organizations t o b r i n g the best o f the na t i on ' s ta len ts t o bear d i r e c t l y on the program i n the most e f f i c i e n t manner. A summary o f the major elements o f t he p lan are shown i n Figure 10. The
50 MWt Endurance Power Train element provides the system in teg ra t i on . R e t r o f i t Power T ra in element provides the opportuni ty f o r f u r t h e r scale-up and the t o t a l p l a n t in tegrat ion. Ear ly conceptual design o f t h e power t r a i n f o r the R e t r o f i t f a c i l i t y i s important t o proper i n t e g r a t i o n o f t h e power t r a i n ' ' development program and t o preparat ion f o r e a r l y i d e n t i f i c a t i o n of an request f o r the c a p i t a l funds f o r the R e t r o f i t f a c i l i t y as noted by t h e ca re t a t the middle o f the t h i r d year.
The
The MHD Generator Development element i s planned t o be c a r r i e d ou t a t 50 Wt. The generator, and especia l ly the channel, i s p a r t i c u l a r l y important t o r e l i - able MHD power p l a n t operation and t o low cost o f energy. the channel inc lude performance, l i f e t i m e , economical o f warm bore, r e a d i l y replaced, rugged, r e l i a b l e , and low f a b r i c a t i o n and assembly cost.
The requirements f o r
The development o f t he channel w i t h features s u i t a b l e f o r use i n a supercon- duct ing magnet w i l l be necessary f o r t he R e t r o f i t program. o f the low-production-cost structure, devised i n the MHD Generator study, may requi re more t ime f o r f i n a l demonstration and may not be ava i l ab le i n t ime f o r the f i r s t channel i n the R e t r o f i t program. It w i l l , however, be a v i t a l f a c t o r i n achieving compet i t ive commercial MHO power. The program t o develop the data and in format ion f o r design and manufacture o f low-productioncost channels for the e a r l y commercial p lants can be ca r r i ed ou t w i t h i n the schedule f o r t h e R e t r o f i t program.
Fur ther development
The t o t a l power t r a i n development program, exclusive o f t e s t i n g f a c i l i t i e s and supplies, i s estimated t o cost $278 m i l l i o n . The d i r e c t cos t o f t e s t i n g i s estimated t o cost $10 m i l l i o n . The cos t o f t he R e t r o f i t p l a n t was estimated by the MHO I n d u s t r i a l Forum t o cost $310 m i l l i o n i n add i t i on t o the c o n t r i b u t i o n o f the e x i s t i n g steam plant . Since t h e power t r a i n components, f o r the Retro- f i t p lant , are included i n the power t r a i n development program, some $60 m i l l i o n might be charged against the R e t r o f i t p lant . A l l o ther major t e s t
5-5
' f a c i l i t i e s are already avai lable a t Univers i tcof Tennessee Space Institute, COIF, or a t industr ia l organizations. i n Table 5 .
The cost estimate, by element, i s shown
5.2 THE POTENTIAL OF MHD/STEAM POWER PLANTS JUSTIFIES THE NATIONAL PROGRAM
The potential benefits of MHO w i l l accrue t o the general c i t izenry more than t o industry. T h i s i s so because the benefits w i l l be clean a i r , insured supply of energy resources, reduced o i l imports, reduced demand f o r cooling water and ngw plant s i t e s , and reduced creep of e l e c t r i c power cost .
I t was noted i n the Background Section t h a t the advantages of MHD/steam power plants , when they a re developed and commercially applied, can make a s i g n i f i - cant c,ontribution toward meeting the nat ion 's energy requirements w i t h coa l while ameliorating the environmental impact of coal power production. i n f a c t , a number of potential advantages. I t has been indicated i n previous s tudies and confirmed i n the Task I plant studies tha t MHD/steam power p l a n t s can be developed t h a t w i l l be competitive w i t h modern Coal/steam power plants a t and above about 200 MW(e) t o t a l plant o u t p u t . obtained i n this s t u d y a r e presented i n Figure 11. The reduced fuel cost f o r these ear ly comnercial MHO plants w i l l more than compensate f o r the re la t ive ly la rger (than fo r Coal/steam plants of the same rat ing) capi ta l cost . reduction i n fuel cost i s , of course, achieved through the r e l a t ive ly higher eff ic iency a t ta inable w i t h the MHO plants . presented i n Figure 12.
MHD has,
The economic comparisons
The
The comparative eff ic iency data a re I
The increased eff ic iency real izable w i t h MHO plants a lso produces advantages. The amount of coal t o be mined and transported, per u n i t of energy produced, i s reduced. This reduces the environmental impact of bo th fuel recovery and plant operation. reduced. i s an example. s i t e without increasing the waste heat. growth w i t h o u t developing new power plant s i t e s .
The amount of waste heat, i . e . , cooling water requirement, i s The concept of r e t r o f i t t i n g exis t ing plants w i t h MHO topping cycles
Additional e l e c t r i c output could be realized from an existing This would contribute t o meeting load
5-6.
a
L
TABLE 5 POWER TRAIN PROGRAM COST ESTIMATE - BY O B J E C T I V E
RETROFIT POWER TRAIN Development & Test Equip.
50 MW(t) POWER TRAIN
CHANNEL DEVELOPMENT
$'s - Millions
122
78
78
TOTAL TO PRODUCE PT ENGINEERING DATA BASE
278
Facilities, Modifications, Operation and Escalation are not included.
707075-1SA
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0.8
I I I I I I U 0 SUBEWSQNIC e SUBSONIC
STEAM PLANT. - WESTINGHOUSE (I '* MHD APT STUDY
F i g u r e 11. E f f e c t o f R a t i n g on R e l a t i v e Cost o f E l e c t r i c i t y
60 I I I I I
I 'I ULTIMATE MHDBTEAM PLANT
EARLY COMMERCIAL MHDlSTEAM PLANT
REFERENCE COAUSTEAM P ~ A N T
I I I I I 100 400 8w mo
PLANT RATING - MWe
F i y r e 12. E f f e c t o f Rat ina on Performance
*Seikel, G . P., "Status o f Coal Fired Open Cycle MHO Steam Power Plant Studies in the United STates," Specialists Meeting on Coal Fired MHO Power Generation, Sidney, Australia, 1981, The Institutio? o f Engineers, Australia, National Conference Publication No. 8217, V o l . 11, p. 7.1 .l-7.1.13.
' The plant study results may be considered wirh confidence since, as noted above, these efficiency improvements are predicated on power train design limits and parameters that are presently accepted or are judged to be demon- strable in the proposed development and test program described in Section 5.1. Scale-up in rating and lifetime, increase in reliability, and production approaches to meet component cost goals are the primary remaining uncertain- ties. It is also noted that these results are consistent with other studies such as the Evaluation of Conversion Alternatives Studies (ECAS) conducted for DOE/NASA some years ago.
-4
The concept o f retrofitting exist'ing oil/gas fired units with MHD topping cycles is feasible and the MHD units should be readily permitted since they offer the potential of very low emissions of oxides of sulfur and nitrogen. The confirmation of low emission capability is well underway in programs at the University of Tennessee Space Institute and their results support the analyses conducted in this project. This application could contribute to the reduction of need for imported oil.
Incidentally,.the potential for low emissions of sulfur exists for eastern high sulfur coal as well as for the low sulfur western coals. be a contributing factor to the economic rebirth o f Appalachia as well as to the resolution o f the pollution problems threatening the entire northeast region of the nation.
This advantage might
Therefore testing with various coals is recommended.
5.3 THE TECHNOLOGICAL BASE FOR THE PROGRAM HAS BEEN DEMONSTRATED
Every high technology program proceeds through s i x fairly well defined phases between inception and commercial acceptance. These are depicted in Figure 13. The MHD technology was demonstrated to be at the early stage of the Engineering Development phase. research and development has been accomplished over the past decades. Numerous preliminary engineering studies and conceptual designs, of which the APT studies are the latest, have been completed. Breadboard components and systems have been tested. Long operating times have been achieved in very small
The concept of MHD power is quite old and extensive
I
i
I’ ENGINEERING
DEVELOPMENT I I I
I I I I I I
PROGRAM TARGETS
I I I
I PLANT
INTEGRATION
vl I -I
PHASE DEFINITION
0
r
MHD EMPHASIS
F l g u r e 13. MHD Program Phases i
( k i l o w a t t ) systems. (seconds). tes ted f o r short times (hour s ) .
Very h i g h power has bceen achieved f o r very short times Engineering concepts of su i tab le components have been devised and
The MHO/APT project has made unique contributions t o the understanding of the design of the M H O generator by considering the three principal elements of the generator (channel, magnet and power conditioning) as an integrated u n i t . MHD generator operation a t h i g h (6.5 Tesla, peak) magnetic f i e l d s t r e n g t h ( w i t h concomitant substantial performance improvement) i s now possible. FurtheT, t h i s improvement was demonstrated t o be achievable w i t h i n present l imitat ions on e l e c t r i c a l , gas-dynamics and thermal operating parameters and s t resses .
Specific unique and original contributions t o MHD generator technology include:
a ) local plasma management through ac t ive control of individual electrode currents (and voltages),
b ) generator performance improvement and optimization through design f o r mixed loading (drawing Hall generator as well as Faraday currents) ,
c ) r e l i a b i l i t y and l i fe t ime enhancement through I&C concepts t h a t can be developed t o recognize and ameliorate the e f fec ts of electrode-to-electrode f a u l t conditions, along w i t h o ther supporting design features,
d ) generator production cost reduction through concepts t h a t minimize dimensions, hand labor, and the number of special par ts .
A power management subsystem concept was devised w i t h the capabi l i ty t o provide the already recognized current collection and consolidation (from the hundreds of electrode pairs t h a t make up the channel) function and provide other advan- tages. limit the voltage o r current a t each electrode independently of a l l others. The control can be f l ex ib l e i n t h a t i t may control voltage a t one time and current a t another. The control can be varied as the operating mode of the
The proposed power electronics package can be used t o control and/or
5-1 1
’ plant is changed. recognize and eliminate, or at least limit the consequential damage o f ,
electrode-to-electrode faults.
It is anticipated. that tge system can be developed to
The versatility of the power management concept also provides new freedom ior the channel designer. For example, the ability to control local currents makes it possible to select different operating modes (drawing Hall current as well as Faraday current) in selected sections of the channel. This technique permits the designer to take full advantage of the permissible design p a r a w eters to realize the highest overall power density and operating efficiency.
In sumary, this power management concept offers the possibi ity o f managing the MHD plasma through control of the boundary conditions to avoid the local stress conditions in the channel that are life-limiting. It will, therefore, contribute to realizing the full potential of the MHO generator in performance, reliability and lifetime.
The confidence that this power management concept can be developed and utilized is supported by work that Westinghouse has done for DOE and EPRI in the development and demonstration of power conditioning systems for CDIF and fuel cell and photovoltaic power systems. The power electronic devices with which the power management system will be constructed are commercially available. The remaining efforts are in the areas of definition of the specific channel conditions to be controlled, and development of software to produce the desired power management element actions. The first requires channel design definition and very detailed operating data that do not now exist. These must be obtained in actual power train tests and translated into the interface data and informa- tion with which the power electronics experts can define the power management software. The second is (to software experts) a straightforward engineering development assignment.
The power management system should be applied to the 50 MWt power train because every effort should be made to demonstrate channel lifetime and reliability in that test. To meet the projected schedule, the hardware will have to be overdesigned (expanded ranges of voltage and current capability) and
5-12 .
the software w i l l hav t b developed ascth program proceed , probably i n c l u d i n g modification d u r i n g the actual t e s t . makes such modification possible i s a merit o f the concept.
The system f l e x i b i l i t y t h a t
Another innovative Phase I resu l t i s a channel s t ruc ture concept having the potential f o r very low production cost and enhanced r e l i a b i l i t y . of-technology channel features a re retained and incorporated i n t o the proposed approach. For example, copper electrodes w i t h platinum and/or s t a in l e s s s t ee l caps and internal water cooling ( t h a t represent the state-of-technology iit AVCo
The stdte-
Everett Research Laboratory) a re not changed except t o add a fea ture t h a t w i l l provide f o r the necessary retention of s lag and eliminate the need f o r machin- i n g grooves i n each electrode. The thrust of t h e concept, therefore , has been t o take the proven channel features and the known channel requirements and devise low cost manufacturing and assembly means t h a t combine the two. features and approaches t h a t were selected a re a17 based on technology t h a t has been successfully applied i n other f i e l d s , so t h a t the probabi l i ty of success i n t ransferr ing these technologies t o the MHD f i e l d i s h i g h .
The
This channel s t ruc tura l development and demonstration is a major t h r u s t i n the Generator Development element of the development plan, because a r e l i ab le and low cost channel i s absolutely essent ia l f o r the achievement of the national advantages of MHD plants. t o pass wi l l be time consuming. The ultimate evaluation o f these methods must be carried out In actual and complete power t r a i n tests of some duration because the time related concerns, such as creep under thermal s t r e s s i n the f u l l MHD environment, cannot be f u l l y and f i n a l l y resolved i n any other manner.
The engineering development t o b r i n g this t r ans fe r
High power and energy extraction experiments a r e planned t o insure t h a t the analytical code packages f o r the design of large MHD generators include ade- quate representation of a l l performance impacted phenomena (such as secondary flow and magneto-aero-thermal i n s t a b i l i t y ) . These very short time (seconds) t e s t s will continue t o b u i l d on experiments begun a t the Air Force High Power Demonstration Experiment and l a t e r limited t e s t s a t AVCo. superconducting magnet now i n storage a t Argonne i s recommended, pr ior t o i t s use i n the more conventional tasks of the MHD generator development element.
The ear ly use of the
' The remaining components of the power trainh-e under development or represent reasonable extensions of existing technology. that DOE is funding at TRW and CDIF must continue until the practicality of simultaneously meeting the requirements (high slag rejection, tolerance of practical coal grind variablity and low moisture content, uniform and steady plasma generation, efficient recovery of waste heat, and durability) is thoroughly demonstrated. the channel entrance is considered to be a reasonable engineering effort. diffuser will require engineering development that can be carried out in the course of other power train tests augmented by cold-flow component tests. power train instrumentation and control (I&C) system will require design and analytical attention and some instruments will require component development. Integration of the I&C with the total plant I&C system will require similar attention and must await the plant integration program for final detailed definition.
The combustor development effort
The nozzle to produce the required plasma velocity at The
The
This and indeed all of the interfaces with the balance of plant will be a continuing concern until the plant integration is carried out. demonstrated in the Task I plant studies that every power train component has numerous interfaces, above and beyond the obvious mechanical ones, with the balance of.plant. These interfaces have been qualitatively defined in Task I1 in the preparation of the APT System Description and Specification. the detailed quantitative definition of some of these interfaces must await the development of the Heat Recovery/Seed Recovery and Seed Regeneration systems.
It was
However,
This is one cogent reason for the recommendation that these system development programs be pursued in parallel with that for the power train, rather than to proceed with a progressive development program. The opportunity to make the most effective technical and cost trade-offs between the power train and the other systems approaches will be lost unless all the systems are carried forward together and properly coordinated -- the most important function of the integration effort. Fortunately, the DOE program on downstream development (at B&W, UTSI, Argonne and Miss. St. U) has provided the technological base for the engineering development of the HRSR and Seed Regeneration systems'.
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I 5 . 4 TECHNICAL SUCCESS IN THE SHORTEST S C ~ D U L E AND AT LOWEST COST WILL BE REALIZED THROUGH AN INTEGRATED DEVELOPMENT PROGRAM
The APT program opportunity f o r power t r a in w i 1 i n the Retrof i t
through implementation of the Phase I1 e f f o r t , o f fe rs the
be focused and directed t o the key objective of demonstrating, an e f fec t ive and e f f i c i en t program.
project and the MHD Generator development, the p rac t i ca l i t y of
The en t i r e e f f o r t on the
and the enginee.ing basis f o r real iz ing the national benefits of MHD power. The various component development and system studies can be evaluated i n - a cohesive model s t ruc ture (already established i n the SPA/SUMARY code package) so t h a t DOE has the technical tools and data t o manage and d i r e c t the pieces of the M H D program t o come together i n and contribute d i r ec t ly t o the Retrof i t program and t o the .u l t imate commercialization o f MHD.
The value o f the exis t ing component-by-component development i s recognized b u t
i t i s not adequate f o r the scale-up phase of the power t r a i n program. The APT program plan i s predicated on maintaining these programs along w i t h the con- tinued involvement of t he developing organizations. The ex is t ing technology, along w i t h on-going para l le l program resu l t s , w i l l be transferred a s opposed t o i n i t i a t i n g programs of re-invention. I t i s an application of the make-or-buy decision process, i n which equipment and/or services a r e purchased i f pract ical i n preference t o embarking on new e f fo r t s . Experience teaches t h a t there w i l l be suf f ic ien t new business opportunities remaining i n new large programs such as MHD a f t e r the outside sources a re exhausted. The objectives of the program can be realized through the integration of these programs in to the Westinghouse APT program through e i t h e r subcontracting o r GFE methods.
The integration e f f o r t t o rea l ize these benefits o f a t r u l y national program on the power t r a i n was considered and incorporated in to the development plan as shown i n the Work Breakdown Structure given i n Figure 14. integration t o focus the component development in to a cohesive power t r a i n i s an important pa r t of WBS 1100. exis t ing t e s t ing f a c i l i t i e s and t h e i r program plans i s an equally important pa r t of the WBS 1800.
The technical
The coordination of the development w i t h the
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The WBS 1200 was established to provide the-esign and development considera- tion of the MHD generator as an integrated subsystem. accomplish the advantages of the new and innovative power management system and channel structural concepts discussed above.
This WBS element will
The necessity for including the magnet as an integral part of the generator was recognized. inclusion of an unnumbered WBS element) because it was defined as out o f scope in the APT contract.
The magnet i s not included as a WBS component element (note the
It should be included in scope in the Phase I1 effore.
1000 I MHO POWER TRAIN 1
FL---- PROGRAM MANAGEMENT
Figure 14. Work Breakdown Structure First and Second Level
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a
= I t must be considered-in de t a i l i n the WBS 1>00 e f f o r t , aga in -e i the r as a subcontract o r as an integrated GFE system. I t i s impossible t o design and develop the optimum (o r even adequate) power t r a i n , and especial ly the MHD generator, without firm decisions and detai led information on the magnets i n which these quipment must operate.
5 . 5 THE MANAGEMENT AND ENGINEERING TOOLS, EXPERTISE AND CONCEPTS TO CARRY OUT THE PROGRAM TO A SUCCESSFUL CONCLUSION HAVE BEEN IDENTIFIED
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Most of the techniques fo r technical management of large developmental programs such as the power t r a i n a re well'known and many large organizations, especially serving the defense and space markets, pract ice them on a regular basis. industr ia l organizations serving the u t i l i t y market a r e generally less famil iar w i t h these tools . Westinghouse i s one of a very few organizations t h a t a r e not only familiar w i t h these tools b u t have already adapted them t o u t i l i t y o r i - ented programs. capabi l i ty .
The
The success i n the Phase I APT e f f o r t was la rge ly due t o t h i s
Adapting the tools t o the specif ic needs of MHD is not an easy task . important t o s e l ec t those elements of technical management t h a t a r e necessary and re jec t those t h a t a r e not required b u t would add s igni f icant ly t o the program cost i f retained. The experience gained i n applying Air Force 375 t o the Nuclear Rocket Engine Application, PMS t o the Clinch River Breeder Program, and adaptations of these tools t o t o t a l plant and development programs i n commercial nuclear. and new conventional power projects, was applied. Most of the personnel working on the Phase I1 e f f o r t have had personal hands-on experi- ence i n both levels of system management methods. Successful performance of the Phase I e f f o r t was the r e su l t , described herein, achieved w i t h i n budget and schedule.
I t is
The level and degree of application of these tools will be raised a s required i n the execution of Phase I1 of the project. t a n t where numerous organizations a re carrying out portions of the program. The documentation f o r proper and economical direction of the various e f f o r t s wil l be provided f o r use by Westinghouse and DOE management.
T h i s will be par t icu lara ly impor-
Typical examples of such documentation includeYhe Power Train System Descrip- tion and Specification, and the Development Plan both produced in Phase I. On initiation of Phase 11, agreed upon versions of these and other related docu- ments will be placed under control procedures and will be changed only after agreement by the affected parties and approval by DOE. Made available to all parties participating in the program, they will form the framework within which each organization will perform their portion of the power train development effort so that the various results will conform to the coordinated and integra- ted whole power train.
Appropriate progress review and reporting procedures will also be applied to insure that the Westinghouse APT effort is properly directed and that DOE has the latest data and information for their management of the various related projects. A key responsibility of the APT Project Manager will be the call and conduct of regular project reviews that include all participants in the pro- gram. These reviews will be conducted in such manner as to identify progress against the Development Program Plan and to identify potential problem areas at the earliest moment. Variance Report designed to provide APT and DOE management with information to focus their attention on the critical issues. These reviews will also be conducted to identify new information that can update the System Description and Specification (and related documents such as Equipment Specifications on individual components) or call out needs for changes in data or information previously included in these documents. Such needs will be presented in Change Request format that will describe the requested change and rationale. Such
. ..
Such problem areas will be recorded in a follow-up
Change Requests will be evaluated for impact on other elements of the program and referred to a Change Control Board. The Change Control Board will be made up of senior personnel drawn from the various participating organizations to provide the best available expertise to the deliberations. will be referred to DOE for approval and/or implementation, depending on the affected organizations. Once approved, the change will be reflected into the control documents (Plans and Specifications).
Recommended changes
Technical as well as management tools have been identified. For example, Computer Aided Design (CAD) will be applied. By establishing terminals at the
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various organizational locations, agreed upon"configurationa1 changes can be implemented on very short notice and all parties will be assured of data that is up to the minute and that their design is thoroughly consistent with that of mating equipment. delay and cost of conventional drawings.
Design information can be exchanged rapidly without the
The continued use of the SPA/SUMARY code package and plant models will allow the rapid consideration of potential design alternatives at very reasonable cost. reason such as availability of adequate materials or dimensional interferences) the power train integration functi'on, WBS 1100, will be prepared to study and recommend options that can resolve the concern.
As problems arise in the development of any component (for whatever '-
.
The examples cited above, along with many others, will be used in the success- f u l execution of Phase I1 of the MHD Advanced Power Train program.
