1 Highlights
Peaking Power: Prologue Peaking Power: Introduction Chapter 1: The Brayton Cycle
Chapter 2: Time Line – Gas Turbine Technology Chapter 3: Gas Turbine Performance, Simplified Chapter 4: Sir Frank Whittle, Father of the Gas Turbine Chapter 5: Gas Turbine Planes, Trains and Automobiles Chapter 6: Rutland on the Leading Edge
Chapter 7: The Fuel Regulator
Chapter 8: Compressor Drives for the Industrial and Gas Pipeline Industry Chapter 9: Enter the Peaking Power Package Plant
Chapter 10: The Great Northeast Blackout Chapter 11: The Long-awaited Frame 7 Chapter 12: The Mighty MS5002 Gas Turbine
Chapter 13: Speedtronic™ Control and Protection Systems Chapter 14: The Arab Oil Embargo of 1973 – 1974
Chapter 15: Cogeneration and Combined Cycle Chapter 16: Computerized Control Systems Chapter 17: The Long Anticipated 7EA!
Chapter 18: Conversions, Modifications & Upgrades Chapter 19: Metals, Ceramic Coatings & Cooling Chapter 20: F-Technology and Beyond
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Peaking Power – Prologue
Black Start – Prologue
The study hall in Du Bois library was quiet in the din of autumn that evening in November, 1965. Such was life at the University of Massachusetts at Amherst, MA. Winter was rumored to be just around the next blustery bend. Mid-term exams wouldn‟t let me think about the Thanksgiving break coming later that month.
I should have been studying at this hour of 5:30 pm. As I recall, a pretty blonde co-ed (unnamed here) captured my eyes and imagination. Unfortunately for me, I didn‟t have hers. So there I was day dreaming (not about thermodynamics, as I should have been), when all of a sudden the lights flickered in the expansive study hall with long tables and uncomfortable wooden chairs. A few moments later, the lights flickered again and went out to stay. There was no thunder and no lightening. What just happened? A buzz came over the room.
A few seconds later, I heard a deep voice: “This is God speaking.” Everyone around me chuckled. Some wise guy, no doubt. “Due to lack of interest, today has been cancelled.” The laughs were louder now. It wasn‟t quite dark outside but everyone in the hall began loading books into their backpacks and making their way to the exits where emergency lights were dimly lit. Something definitely had happened. It wasn‟t but two years after another November event when President Kennedy had been assassinated, so I‟m sure some students, like I, had considered something ominous had happened. Or was it a Soviet nuclear attack in retribution to Kennedy‟s blockade of Cuba in October 1962?
That was my first experience with blackout conditions. It wouldn‟t be the last. November 9, 1965 was the day that came to be known as The Great Northeast Blackout. States along the eastern seaboard went dark and stayed that way for a dozen hours. New York State was perhaps the darkest, as the power system collapsed from Niagara Falls near Buffalo to New York City. Long Island was blacked out as well.
I learned many years later that a lone gas turbine generating plant in the town of Southampton, NY, on the eastern tip of Long Island, was the only one in the region with “black start” capability. That is, this power plant manufactured by General Electric (GE), could start on battery power using a diesel cranking engine. It could fire, warm-up and accelerate to full speed on #2 distillate fuel oil from a nearby storage tank. It took approximately eight minutes after an emergency start signal was initiated. The good news was, the turbine performed as expected. This little GE 12-megawatt generator was credited with restoring power to Long Island and eventually New York City.
Little did I realize that day in fall of 1965 that a career in gas turbine field service engineering would be in my future. I was hired with General Electric the following year. After eighteen months in technical marketing training, I opted to change my career direction. I was hired in 1968 by their international service organization called General Electric Technical Services Company, better known by everyone in the business simply as GETSCO (pronounced Jets-co).
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After a brief period in training on the new Field Engineering Program (FEP), I was sent to Chicago to assist in the installation of three 4-unit GE gas turbine power blocks. These twelve package power plants could start and operate on either natural gas or liquid fuel. Commonwealth Edison Company, at their Crawford Station, needed peaking power in case that region ever experienced a power emergency. Also, one of the Dresden nuclear plants was seriously behind schedule, so these units were immediately put into service for base load operation. At the time, they ran only on liquid fuel, as the gas fuel system was not commissioned until years later.
A few months later, I was called back to Schenectady, NY to enter the Gas Turbine Start-up Program. The program lasted about one year. We were trained on current and new control systems. The current controls on MS5001LA gas turbines utilized the Young & Franklin fuel regulator. The first electronic system, first used on MS5001N gas turbines, was GE‟s Speedtronic™ Mark I. We were trained to provide start-up support on both systems.
After the training period, in the May 1969, an emergency call came in from a site in Escuintla, Guatemala. No longer considered a trainee, I was dispatched to the capitol city and later driven down toward the Pacific side of the country. Along with another engineer, Willie Brandt (no relation to the former leader of Germany) and I were sent to a flooded region of the country to “bailout” two GE gas turbine generators. We were there for about a month. Torrential rains came every day and we had to cross over a river (sometimes by cable and a stirrup chair), to get to the power plants.
This GE year-long start-up program gave me extensive controls and start-up experience on several assignments within the USA and overseas. Over my career, I‟ve worked in more than 20 countries for GE and a few countries more since then. It was the beginning of a 40+ year career in gas turbine field engineering.
I dedicate this blog endeavor to all the friends and associates I have had in the gas turbine business and in particular, the field engineers and those associated with the Field Engineering Program (FEP). We call ourselves “Turbine Cowboys.” Visit www.turbinecowboy.com to learn more about the guys and gals who have become field engineers in the power generation business. Please read on and comment.
- David Lucier
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Peaking Power – Introduction
Black Start – Introduction
Since its introduction toward the end of World War II in jet aircraft, the applications of gas (combustion) turbines have been myriad. Some uses have been successful, others have not. In most cases, the failures were not because of ill-conceived applications. More often it was a case where they were “ideas whose times had not yet come.”
Note: For the most part herein, I will refer to these types of prime movers as gas turbines, even though some only burn liquid fuels. Also, some in the industry use the term combustion turbines, but my GE experience makes me prefer the word gas.
Gas turbine applications in some industries were tried in earnest but never came to fruition. For instance, even though the Union Pacific Railroad gave gas turbine locomotives a good look by ordering a fleet of units from ALCO with GE engines in the late 1940s to propel cargo and passenger trains. However, high-frequency whining from the compressors limited their use to “open spaces” of the far western United States or Canada. Out in the plane states and mountains ranges, air-borne noise was less of an irritant to far away townships. What if compressor noise attenuation had been made an engineering design priority, using inlet silencing, would turbo-powered trains then been allowed to pass through more densely populated city areas?
Automobiles were another potential application in the 1950s and 1960s. A British company named Rover tried gas turbines in sedans and commercial vehicles. What if the Rover Jet One car had been victorious in road racing? Suppose the Rover BRM race car actually won the 24 Hours Le Mans race in 1965, defeating the Ferraris and Porsches instead of finishing a respectable tenth? Certainly gains in reducing fuel consumption made the Rover race cars more efficient when regenerators were installed in the turbine exhaust. Regeneration was used to recover the exhaust heat to pre-heat compressed air entering the combustor. Here‟s another scenario: Suppose the Granatelli-designed Studebaker gas turbine car, piloted by the famous racer Parnelli Jones, had actually won the Indianapolis 500 in 1967, instead of slipping to fourth place due to a minor gearbox component failure? Had this part not failed, having nothing to do with the gas turbine power plant and the turbine car taken the checkered flag, would turbine- powered vehicles (trucks and other long-distance carriers) become popular for cross-country transportation? In racing they say: “what wins on Sunday, sells on Monday!”
Air travel was another thing in the 1950s. Former Pan American Airways CEO, Juan Trippe, favored jet-powered commercial airplanes and did much to propel a reluctant transportation industry. Trippe envisioned non-stop, international air travel. He forced the industry away from turbo-prop aircraft. This act of “arm twisting,” along with the fear of European competition, made companies like Boeing, Lockheed, General Electric and Pratt-Whitney develop jet engines for commercial aviation. Decades later, after the advent of such innovative aircraft as the Boeing 747 and the supersonic Concorde, the traveling public thinks nothing of hopping cross-continent airplane and even nonstop from New York to Beijing, a 14 hour trip. The gas turbine (jet) has been an obvious commercial aviation success story.
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Note: I got to fly on one of the first Pan American 747 from Hong Kong to Tokyo in 1971. What a thrill that was. I had just spent 5 months installing two GE gas turbine PPP north of Saigon, Vietnam. It was a treat to fly on the maiden flight in the Far East.
It took a couple of decades for gas turbine electric power generation to come into its own. Perhaps no event in history has had more impact on emergency electric power generation by gas turbines as The Great Northeast Blackout of November 1965.
Fig. I-1: Dark Days – Transmission Lines Suddenly “Darkened” During a Blackout
Gas turbines with “black start” capability were in high demand for a decade thereafter. The bottom fell out in the USA, however, with the Arab Oil Embargo of the winter of 1973 and 1974. These two events form bookends for the history books for the highpoint era for gas turbine emergency power installations. For the next ten years, however, island countries of the Caribbean were not deterred. In the middle of the decade, the 20 megawatt GE frame 5 package power plant became very popular for its rating and quick response to needs of a region plagued by frequent hurricanes. The Bahamas, Virgin Islands, Aruba, Curacao and other islands placed orders with GE, Westinghouse and others. Oil-producting countries like Venezuela, Colombia and Mexico, ordered hundreds of GE frame 5 and Westinghouse 251 units.
The impact of the gas turbine on power generation in the USA took another decade to recover. It wasn‟t until the advent of co-generation (co-gen) power plants in the early 1980s that gas turbines made a comeback as an alternative power sources. Co-gen plants were constructed next door to “steam hosts” like paper mills, salt plants and other industrial facilities. Combined-cycle (CC) plants became popular as well as in the 1990s. The electricity that was simultaneously produced was more of a byproduct in co-gen applications than a primary raison d‟etre. Furthermore, as efficiencies improved for combined-cycle plants of the 1990s, reaching targets above 50 percent, so gas turbines became the method of choice for many electric utility
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companies and industrial plants. Siting for nuclear power, as well as coal-burning plants, took far longer to be realized, as compared to gas turbine generation. Nowadays, the reference has changed from co-generation to combined heat and power (CHP).
So we come to these questions when we consider the gas turbine as a prime mover. What if can be a fun game to play, as follows:
• What if… the problem of compressor noise had been resolved, permitting trains to operate in cities, would gas turbines have become common prime movers for trains?
• What if… Rover gas turbine cars of the early 1950s proved to be a viable means of day-to-day transportation in England, would we all be driving turbine cars today?
• What if… the Northeast Blackout of 1965 had been averted? Would GE and others have abandoned research and development of the gas turbine?
• What if… the Rover BRM turbine-powered car won the 24-hour race at 1965 LeMans, would enduro-type cars be all gas turbine powered today?
• What if… Andy Granatelli‟s gas turbine car actually won the Indy 500 in 1967? Would Indy-car engines be all gas turbines today? I repeat here the adage in racing: “What wins on Sunday, sells on Monday.”
• What if… the Arab-Israeli war had not resulted in the Arab Oil Embargo of 1973 – 1974? Would the OPEC countries have had far less influence on oil consuming countries today?
Sometimes forces more powerful than just “good ideas” come into play. However, it is still fun to play What if…
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Peaking Power, Chapter 1: The Brayton Cycle
Black Start, Chapter One: The Brayton Cycle
The individual most commonly associated with the concept of the combustion (gas) turbine engine was an American named George Brayton (1830-1892). He was an engineer with vision and ingenuity, who conceived the gas turbine thermodynamic cycle back in 1872, when he filed for a patent. Discussions about gas turbines need to begin with Brayton.
Brayton conceived an engine that compressed atmospheric air to a high pressure. In his concept turbine, the compressed air would then be mixed with a fuel (most commonly natural gas or #2 distillate oil) and ignited in one or more combustion chambers. The excess air (that is, air not needed in the combustion process) would then be used to dilute and reduce the high-temperature combustion gases to a more moderate level, without significantly reducing the pressure leaving the combustors. This would be known as combustion at constant pressure.
In Fig.1 below, air from the atmosphere adjacent to the turbine is drawn in and compressed, as shown from point 1 to point 2. Notice that the volume decreases as the pressure rises. Heat is then added between points 2 and 3 on the graph. However, the pressure remains essentially constant, as represented by the horizontal line on this pressure-volume (P-V) diagram.
Take a few minutes to study all aspects of the graph below. Pressure is on the vertical axis (ordinate); Air Volume is on the horizontal axis (abscissa). Notice how volume decreases as pressure increases along the up slope from Point 1 to Point 2. Trace the line from the Start Point 1 around to Point 4. Imagine how the pressure and volume change along the route. Notice where heat is added to the compressed air.
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Thereafter, the hot gases expand through stationary nozzle segments that direct the flow to impinge on the turbine blade surfaces (a.k.a. buckets) and develop torque (power). According to Brayton, power will be developed by the gases applying impulse forces on the turbine rotor blades. Additional power results from reaction forces of the hot gases accelerating away from the turbine blades. These TWO forces develop rotational power to turn turbine wheel(s).
An extension shaft from the turbine wheels would then be connected to an electric generator or other load device to do useful work. Brayton envisioned that approximately 2/3 of the power developed by the gas turbine would be required to drive the turbine‟s own axial-flow compressor and such required auxiliaries as fuel, oil, hydraulic and water pumps. Finally, the exhaust gases would then be sent to a diffuser (to reduce the flow velocity) and out to the atmosphere through a stack enclosure.
The Brayton Cycle is considered to be an open system, since the exhaust gases are expelled back to the atmosphere from whence they originated. Please refer to Fig. 2 below.
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The stick diagram (Fig.1-2 above) and the associated pressure-volume diagram (Fig. 1) clearly show the gas turbine in its most rudimentary form.
The four numbered corner points show following modes:
Points 1 to 2: Compression (air drawn from atmosphere and compressed) Points 2 to 3: Combustion (combustion at essentially constant pressure) Points 3 to 4: Expansion (expansion across turbine section)
Points 4 to 1: Exhaust (exhausting hot gases back to atmosphere)
The Brayton Cycle, in its simplest form, is not particularly complicated. However, it took almost 60 years before working engines were developed. This was due, in large part, to the fact that Brayton‟s idea was one whose time had not yet come. Technology lagged behind his concepts because the need was not yet beckoning for such a device as a gas turbine.
The axial-flow compressor requires work to compress the air (W1-2) as shown in Figure 1-1. Energy, in the form of fuel (natural gas or #2 distillate oil are the most popular), is injected into the combustor(s) shown as Q2-3. The output work developed between W3-3’ is required to power its own compressor and auxiliaries. The remaining power (W3’-4) is used to drive a load device (generator or load compressor). The gases going to the atmosphere are hot, but this is often wasted energy (Q4-1), unless heat recovery equipment is employed.
Figure 1-3 below shows gas turbine operation for three different ambient conditions: an ISO day (compressor inlet temperature of 59 ˚F day, which is 15˚C) is represented by the sloped line in the middle. To the left is the characteristic control line for a MAXIMUM ambient day (assume something like 100 ˚F at the compressor inlet). The third line shows a loading curve for MINIMUM ambient day (assume 32 ˚F at the inlet).
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Loading the gas turbine from No Load to Rated Load for the ISO day, the fuel flow and exhaust temperature would track along the center line until the BASE load limit is reached.
If PEAK load is then selected, the curve would track higher to intercept the upper line. On a MAXIMUM ambient day (hot), the governor control would track along the line on
the left until BASE or PEAK load was intercepted, as desired.
Similarly, a MINIMUM ambient day (cold) is reflected in the governor tracking along the right-side line to BASE or PEAK load. Notice that a different BASE load level is achieved depending upon the ambient day of operation. For instance, suppose the outside temperature at the compressor inlet is 32 ˚F, more power would be developed than on an ISO (59 ˚F) day.
Much more power would be developed on a 32 ˚F day than on a MAXIMUM (say 100 ˚F) day, but fuel costs will increase too.
There are some minor efficiency gains on colder days, but for the most part this additional power is developed as a consequence of more fuel being burned in the combustors. This raises the pressure acting on the turbine blades (buckets). It costs the gas turbine operator more in fuel for the additional power generated. However, the cost per kilowatt generated decreases.
George Brayton never lived to see his concept engine, the gas turbine, become a reality. If he lived today, the F-class gas turbines that develop upwards of to 200 megawatts would likely bring a grin to his face some 14 decades later.
Tags: Brayton Cycle, Combustion, Compression, Exhaust, Expansion, gas turbines, George Brayton, Pal Engineering, turbines
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Peaking Power, Chapter 2: Time Line – Gas Turbine Technology
Chapter Two: Time Line – Gas Turbine Technology150 BC – A Greek philosopher and mathematician, Hero, invented a toy (called an aeolipile) that rotated on top of a boiling pot of water. This caused a reaction effect of hot air or steam that moved several nozzles arranged on a wheel. This works when one understands the Third Law of Motion – Every action produces a reaction, equal in force and opposite in direction.
1232 – Chinese began to use rockets as weapons. The invention of gun powder uses the reaction principle to move rockets forward.
1500 – Leonardo da Vinci drew a sketch of a device called the chimney jack, which rotated due to the effect of hot gases flowing up a chimney. It looked like a device that used hot air to rotate a spit. The hot air came from the fire and rose upward to pass through a series of fan like blades that turned the roasting spit.
1629 – Giovanni Branca developed a stamping mill that used jets of steam to rotate a turbine that then rotated to operate machinery.
1678 – Ferdinand Verbiest built a model carriage that used a steam jet for power.
1687 – Sir Isacc Newton announces the three laws of motion. These form the basis for modern propulsion theory.
1791 – John Barber received the first patent for a basic turbine engine. His design was planned to use as a method of propelling the „horseless carriage.‟ The turbine was designed with a chain-driven, reciprocating type of compressor. It had a compressor, a combustion chamber and a turbine.
1872 – Dr. F. Stolze designed the first true gas turbine engine. His engine used a multistage turbine section and a flow compressor. This engine never ran under its own power.
1903 – Aegidius Elling of Norway built the first successful gas turbine using both rotary compressors and turbines - the first gas turbine that actually delivered excess power.
1897 – Sir Charles Parson patented a steam turbine which was used to power a ship. 1914 – Charles Curtis filed the first application for a gas turbine engine.
1918 – Dr. Stanford A. Moss developed the GE turbo-supercharger engine during W.W.I. It used hot exhaust gases from a reciprocating engine to drive a turbine wheel that in turn drove a centrifugal compressor used for supercharging. General Electric Company started a gas turbine division.
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1920 – Dr. A. A. Griffith developed a theory of turbine design based on gas flow past airfoils rather than through passages.
1930 - Sir Frank Whittle, in England, patented a design for a gas turbine for jet propulson. The first successful use of this engine was in April, 1937. His early work on the theory of gas propulsion was based on the contributions of most of the earlier pioneers of this field.
The specifications of the first jet engine were: Airflow = 25 lb/sec
Fuel Consumption = 200 gal/hr or 1300 lb/hr Thrust = 1,000 lb (estimated)
Specific Fuel consumption = 1.3 lb/hr/lb
Fig. 2-1 Sir Frank Whittle and his Jet Engine Prototype
1936 – At the same time as Frank Whittle was working in Great Britain, Hans von Ohian and Max Hahn, college students in Germany, developed and patented their own engine design. 1939 - Ernst Heinkel Aircraft flew the first flight of a gas turbine jet, the HE178.
1941 - The 2nd World War and the need for faster flying aircraft changed all that. However, the development of aero-derivative engines had to evolve as well. But the war wouldn‟t wait. Not only that, it ended before the Allied Forces (in particular, England and a brilliant engineer named Frank Whittle) could get its jet-powered aircraft aloft.
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The Americans never got fighter planes in the air before the allied victories in Europe and Japan. However, when the war economy evolved into an industrial economy in the late 1940s, the conversion of the jet engine to other applications (air, land, rail and sea) followed and the result was the combustion (gas) turbine.
1942, April 11 - David Lucier is born. Little did anyone know at birth that his destiny was to have a career in field engineering services in gas turbine technology, since he was more interested in sucking on a warm bottle of milk. He didn‟t invent a single thing in his lifetime. He did, however, service many GE gas turbines throughout the world during a 40+ year career.
Fig. 2-2 Older brother Stephen and Fat David (age 8 months in 1942)
1942 – Dr. Franz Anslem developed the axial-flow turbojet, the Junkers Jumo 004, used in the Messerschmitt Me 262, the world‟s first operational jet fighter. After World War II, the development of jet engines was directed by a number of commercial companies. Jet engines later became the most popular method of powering airplanes.
1949 – General Electric, of Schenectady, NY sold gas turbine locomotive engines that were installed on ALCO (from the same city) trains for the Union Pacific Railroad.
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Fig. 2-3 Gas Turbine Powered Locomotive
1951 – General Electric sells three gas turbine generator drives, dual fuel (#2 distillate and #6 heavy oil) rated at 5,000 KW each were installed at Central Vermont Public Service in Rutland, VT. Units were nicknamed the “Kilowatt Machines.” The power plants were intercooled, regenerative cycle that operated at base load. Dave Lucier assisted in troubleshooting a problem in 1988 and was later given the Young & Franklin fuel regulator (serial number 49) and the plant nameplate from Unit #1, for his service help. The last of the three units were retired in 1989 and sold for scrap.
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Fig. 2-4 Kilowatt machine at CVPS in Rutland, VT (1951)
1953 – General Electric sells two frame 3 gas turbine generator drives, dual fuel (natural gas and #2 diesel), with on-line, auto transfer, to Montana Dakota Utilities in Williston, ND. Units are still in operation as of 2010. Rating 4,000 KW for each.
Fig. 2-5 Montana Dakota Utilities MS3001 Gas Turbine at Williston, ND (1957)
1957 – General Electric sold their first frame 3 steam turbine and gas (STAG) plant to the City of Ottawa, KS. In 2010, the unit is still operational. Dave Lucier’s company, PAL Turbine Services, LLC, conducts borescope inspections in October 2010.
1965, November 6 – The Great Northeast Blackout. MS5001D Package Power Plant (PPP), installed at Long Island Lighting Company plant in Southampton, NY, is credited for restoring power on the island, feeding back to New York City. GE begins selling the PPP design and 4-unit Power Blocks like “hot cakes.” Hundreds are shipped in the next 5 years.
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Fig. 2-6 Black Out Along NY State Transmission Lines (1965)
1966, September – David Lucier graduates (finally) from the University of Massachusetts, Amherst. His mother is pleased. Lucier begins work for General Electric on the Technical Marketing Program (TMP) in the Power Transformer Department in Pittsfield, MA. He is unhappy living at the YMCA. His mother is happy he doesn‟t quit GE because he needs “a job to pay off his college loans.”
1967, June – David Lucier is offered a transfer assignment on the TMP to the Gas Turbine Department in Schenectady, NY. With practice, Lucier learns how to spell the name of the city. He likes gas turbines, but a friend with a brand new black 1969 Corvette convinces him that a working at a field engineer (What‟s that?) might be a wise career change. The Corvette was a motivator for Lucier.
1968 – David Lucier changes careers and enters the GE Field Engineering Program (FEP). He is sent to help install three 4-unit power blocks at Crawford Station for Commonwealth Edison Co. in Chicago, IL. The twelve turbines were GE MS5001L package power plants (PPP) rated at 15.000 kilowatts each at NEMA conditions.
Lucier likes working as a field engineer because of several factors
1. 60-hour weeks that include 20 hours of paid overtime (Lucier begins paying off his college loans making his mother happy!).
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3. Rental car was a 1968 Dodge Charger (Avis mistake). Lucier refuses to surrender the car until the concludes.
4. Some beautiful women in Chicago for Lucier to meet and enjoy
Fig. 2-7 Lucier traveling to work on a flooded gas turbine site in Guatemala (1969)
1968 – David Lucier is assigned to the Gas Turbine Start-up Program and begins a 40+ year career in field engineering services. He worked for General Electric Technical Services Company (GETSCO) for about 5 years in his first field career. Lucier is sent to work abroad on gas turbines in over 20 countries. In 1971, Lucier is reassigned as Area Engineer for Venezuela, Colombia and Caribbean Islands including Aruba, Curacao and Isla Margarita. His first field career ends in June 1973.
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Fig. 2-8 Lucier and associates at power plant in Vietnam (1971)
1971 – GE produces first MS7001A gas turbine Package Power Plant. First unit shipped to Long Island Lighting Company in Babylon, NY. It was one of the first gas turbines with Speedtronic™ Mark I and electro-hydraulic fuel controls.
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Fig. 2-9 Lucier at power plant in Venezuela (1972)
1973 –1974: The OPEC Oil Embargo. Members of oil-producing nations create a world-wide crisis that lasts many months, driving up costs for gasoline and heating oil.
Motorists and home owners in the USA experience fuel shortages and gas stations limit hours of operation. Some stations limit sales to just $1.00 worth of gasoline per visit. Also, alternating days (odd-even license plates) become common in some states like Massachusetts.
Significant reduction in demand for gas turbine power plants in the USA begins and lasts over the next decade. However, OPEC nations in the Middle East and Caribbean Islands still order PPP from GE for their specific applications.
1982 – GE introduces a cogeneration (Co-Gen) plant using the new MS6001 gas turbine. The so-called frame 6 turbine was a hybrid design between the frame 5 and 7. It had a 17-stage compressor like the frame 5 and a 3-stage turbine like the frame 7. The first units have Speedtronic™ Mark II controls. The turbine was exhaustively tested at the Schenectady Plant Outdoor Test Site (dubbed SPOTS) in the early 1980s. Later in the decade, the Mark IV
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computer-based control systems are introduced. Co-Gen nowadays is known as Combined Heat and Power (CHP) in the industry.
1983 – 1988 – GE begins to install STAG plants worldwide. STAG stands for steam turbine and gas. These plants use either the new MS7001E (60 cycle generators) or MS9001E (50 cycle generators). Fourteen STAG-109E gas turbine plants, totaling 2,000 MW of power, go into commercial operation for Tokyo Electric Power Company (TEPCO) in Futsu, Japan in 1988. At the time, this site was the largest gas turbine installation of its kind in the world. These turbines began with Speedtronic™ Mark II controls but were later upgraded to Mark V.
1983-1985 – David Lucier is assigned by GE to work at TEPCO in Futsu, Japan. He heads a group of 15 field engineers on this assignment. He is succeeded by Muggs Norris and finally Dave Smith, who was initially headed up the start-up team.
1986 – David Lucier voluntarily resigns from GE. He starts his first company: I&SE Associates of Schenectady, Inc. I&SE provides field engineering services on GE gas turbines including training, troubleshooting and consulting. Company is disbanded in 1998.
1991 – GE introduces the MS7001EA gas turbine (evolved from the 7B from 1970) which is rated at 90 MW for ISO conditions. Firing temperature is 2200˚F. Speedtronic™ Mark V is introduced. Dry Low Nox (DLN) systems are first employed.
1999, June – David Lucier and Charles Pond start a new company: Pond and Lucier, LLC. Company provides field engineering services for owners and operators of General Electric gas and steam turbines.
2000 – GE introduces the MS7001FA gas turbine which is rated at 150 MW for ISO conditions. The so-called “F” technology can fire at a temperature of 2400˚F. Turbine utilizes Speedtronic™ Mark VI controls.
2004 – GE introduces the MS9001H gas turbine (50-cycle) which is rated over 200 MW for ISO conditions. The so-called “H” technology has steam-cooled turbine buckets and can fire at a temperature of 2600˚F with Mark VI controls.
2010, January – Dave Lucier buys out Pond and becomes sole owner of Pond and Lucier, LLC. Name is changed to PAL Turbine Services, LLC.
Thus, we have the Time Line of Gas Turbine Technology. Tags: gas turbines, turbines
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Peaking Power, Chapter 3: Gas Turbine Performance, Simplified
It is generally known by observation that gases have particular characteristics. Variables like pressure (P), temperature (T) and volume (V) have a special relationship in gases that is best understood when considering the model below. In words, Pressure (P) multiplied by Volume (V) and then divided by Temperature (T) is always constant. It is a different constant for each gas. Air, which includes many gases, would have still a different constant than the particular gases in the mixture. Finally, when fuel (natural gas, for instance) is mixed with air in a gas turbine combustion system, still another constant is realized. However, when considering the various stages of the Brayton Cycle, the specific constant does not matter in the analysis.
In equation form, that would be: (P) multiplied by (V) then divided by (T) = constant
or simply (P x V) ÷ T = constant
This relationship holds through all stages of the gas turbine. It is important, however, that the units of each of the three variables be correct. In English units, that would be:
Pressure (P) in pounds per square inch absolute, (psia)
Temperature (T) must be in degrees Rankin, (˚R). That is, to convert from Fahrenheit to Rankin, it would be: T (˚R) = T (˚F) + 460
Volume (V) must be in cubic inches, (in³) Or it can be said, simply:
P (psia) x V (cubic inches) ÷ T (degrees R) = constant
For the four regions of the gas turbine on the pressure-volume (PV) diagram we have: Region 1 – 2 Region 2 – 3 Region 3 – 4 Region 4 – 1
Compresion Combustion Expansion Exhaust Thus, we have:
P1 x V1 = P2 x V2 = P3 x V3 = P4 x V4 T1 T2 T3 T4
Imagine a cubic foot of air. Assume that the “box” of air has dimensions of 12 x 12 x 12 inches, as it enters the compressor. Try to envision this air cube passing through the gas turbine.
From the compressor inlet (point 1) the air cube passes through the axial-flow compressor diminishing in size through each stage.
The air cube, now smaller in size, leaves the compressor discharge (point 2) and enters the combustors at essentially the same pressure. That is, P2 = P3.
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Then the smaller air cube expands through the combustors to the first stage turbine nozzle, to a point just in front of the turbine buckets at essentially constant pressure (point 3).
After expanding through the turbine stages, the air cube increases in size, continuing out the exhaust reaching approximately the same pressure as the compressor inlet (point 4), That is, P4 = P1.
Fig 3-1 - Brayton Cycle-Pressure Volume Diagaram
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We know that pressure, volume and temperature are variables. However, they only vary throughout the gas turbine cycle in the relationship described above. Also, notice that the pressure from points P2 to P3 is considered constant, horizontal line on the P-V diagram. Thus, in the combustion zone, they would then P2 and P3 cancel out on each side of in the following equation leaving:
V2 = V3 T2 T3
The formula only works for temperatures in degrees Rankin. Converting to Fahrenheit we have ___V2___ = ___V3___
(T2 + 460) (T3 +460)
Take a typical General Electric model series MS5001P, a very popular gas turbine in the world-wide market. Assume that the turbine firing temperature is Tf = 1800 degrees Fahrenheit. Assume that the air temperature at the discharge of the compressor is approximately 500 F. Thus, we would have:
___V2___ = ___V3___ (500 + 460) (1800 + 460) ___V2___ = ___V3___ (960) (2260)
Thus, in the gas turbine‟s combustion system, the pressure remains essentially constant (P2 ≈ P3). However, the volume more than doubles, or in this case V3 = 2.35 (V2)
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Fig 3-2 - Compressor End View of a Typical Gas Turbine
View of the gas turbine in Fig. 3-2 above showing the compressor and turbine rotor installed inside the casings. Notice how the compressor stage passageways diminish in size as the air flows through the turbine (getting smaller with every stage). In Fig. 3-3 below, the compressor rotor blades diminish in size from the R-0 stage to the R-16 stage; again, the air passage ways for the air to flow diminish through this 17-stage compressor.
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Fig 3-3 - Compressor Rotor View
Gas turbine performance can be affected by many variables. One of the most important factors is the change of ambient temperature at the compressor inlet. Figure 3-4 below shows how changes in ambient temperature impact such variables as Heat Rate, Exhaust Temperature, Exhaust Flow, Fuel Flow and Power Output. Notice how the Heat Rate (thus the Thermal Efficiency) improves on colder days. Fuel Flow does increase, as does Power Output. However, notice that the slope of the Power line is steeper than that of the Fuel Flow, which flattens the Heat Rate line. More power output for less fuel means higher efficiency.
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Fig 3-4 - The Effects of Changes in Compressor Inlet Temperature
So what can I do to improve gas turbine performance without spending tons of money?
Check compressor discharge pressure (CPD). If it is low, you should clean the compressor by on-line washing or other techniques.
Borescope the turbine on a regular basis. If the trailing edge of the first-stage turbine nozzle is distorted or missing metal, performance will suffer. The forces acting on the buckets that develop power output is diminished by a reduction in back pressure on the compressor reduces CPD.
Be sure that the inlet guide vane (IGV) angles are set properly. This can be determined during a borescope inspection. Incorrect settings can reduce air flow and adversely affect power output.
Record FSNL Data. Once the gas turbine reaches operating speed (called Full Speed, No Load or FSNL), record the following data:
27 1. Compressor Discharge Pressure (CPD)
2. Fuel Flow (gpm, if liquid fuel or SCFM, if gas fuel) 3. Average Turbine Exhaust Temperature (TTXM) 4. Megawatts (MW) – Zero at the moment.
Then begin loading the generator and record power output (MW) and observe the other data points (CPD, FF and TTXM) until base load is reached. These variables should increase in essentially equal proportions from the FSNL data. Once base load is reached, you should determine if the correct turbine firing temperature, Tf is reached. Contact PAL Turbine Services, LLC and David Lucier for assistance in these calculations.
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Peaking Power, Chapter 4: Sir Frank Whittle, Father of the Gas
Turbine
Discussions about gas turbines and their application to land-based power generation, gas pipeline and process plants should rightfully begin with British engineer Sir Frank Whittle. The key word here is application. His predecessors were many, as the time line in Chapter 2 outlines, but Whittle should be credited for bringing ideas regarding the jet engine to fruition in industrial applications.
In 1941, Sir Frank Whittle designed the first successful turbojet engine for air defense during World War II. Dubbed the Gloster Meteor, it flew in defense over Great Britain. Whittle improved his jet engine as the war progressed. He shipped a prototype engine to General Electric in the United States in 1942. GE built America‟s first jet engine for military aviation applications the following year.
Whittle came to the USA for the first time on a secret mission in the summer of 1942. He met with officials from General Electric in Lynn, MA and Bell Aircraft Company in Buffalo, NY. Later in 1942, he visited GE in Schenectady, NY, where a rudimentary propeller jet engine was under development. Whittle‟s comments and suggestions to American engineers proved invaluable in modifications and improvements that soon followed.
One can argue that the development of jet engine might have been accelerated had World War II lasted longer. However, the other side of that argument is that the application of turbo-technology to other industries became a post-war quest of American industry. In the eyes of many engineers on both sides of “the pond,” this method of power production and propulsion could be used to drive land-based generators, compressors and other load devices, as well as to propel ships and aircraft in commercial applications. All that was needed was funding and the imagination of the engineers involved, eager as they were to apply this innovative prime mover.
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Fig. 4-1: Sir Frank Whittle and his multi-combustor jet turbine (circa 1941)
The multi-combustor, turbo-jet engine (hereafter called the gas turbine) has Frank Whittle proudly standing beside it in Fig. 4-1. Notice that there are 10 combustion chambers (tube shaped) encircling the engine, with stainless steel nozzles to inject fuel into them at the front ends. The chambers are interconnected by cross-fire tubes, as is common on most modern gas turbines. The exhaust diffuser is in the center. The reverse-flow concept of the hot gases is obvious from the photograph. So are the transition pieces curling from the discharge of each combustor.
“If necessity is the mother of invention,” as preached to engineering students by college professors, then the end of WW-II brought many needs to the front burner ready to be invented. Jet engine technology needed to be harnessed and applied to other commercial endeavors. As a prime mover, the gas turbine needed to find applications that could deliver power to other modes of transportation, electrical power delivery and natural gas pipelines prime movers. However, as inventors soon found, not every idea has a viable application to industry, or a willingness of the public to accept them. Engineers like Whittle would encounter doubters, the enemies of progressive thinkers. Progress often depended upon inventors who could convince entrepreneurs and angel investors to take a chance on their ideas and innovations. This presumes that negative forces are not overwhelmingly against such visionaries. As explained in later chapters of this blog, GE engineers struggled to get funding in a fledgling gas turbine department in Schenectady, NY in the 1950s.
It is uncertain if Frank Whittle could have envisioned a modern gas turbine like the one shown in Fig. 4-2 below. A single-fuel (natural gas) General Electric MS7001EA gas turbine (approximately 80 megawatt rating) is shown, with fuel line “pigtails” coming from the manifold
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on the left leading to each combustor. The chambers themselves are inside the combustion wrapper, which encircles the turbine, so only the covers are showing.
Fig 4-2; Multi-combustor GE MS7001EA Gas Turbine inside Combustion Wrapper (circa 2000)
Since the combustors are interconnected via cross-fire tubes, only one combustor needs to have a sparkplug (igniter) and another, a flame detector. However, for redundancy and reliability, modern gas turbines typically have at least two of each, as shown in Fig. 4-3.
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Fig 4-3: Typical configuration of Multi-combustor Gas Turbine with Spark Plugs & Flame Detectors
Design of combustion systems, like those depicted herein, seems to be a “settled” issue. Most manufacturers have decided that this is the design that makes the most sense. It allows for temperature equalization and flow distribution to the first-stage turbine nozzle and rotating wheels with buckets (blades) that develop the output power. Refer to Fig. 4-4 below.
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Fig. 4-5 below should be studied for its completeness regarding the design of a typical modern combustion system for a GE MS7001EA gas turbine. Notice that the combustors are “canted” in design to straighten the hot gas flow through the transition pieces toward the first-stage nozzle (not shown). Also, this design shortens the length of the turbine and thus bearing spans. The reverse flow of the air from the compressor discharge casing is also shown entering the combustor.
Fig 4-5: Typical Modern Combustion Chamber and Transition Piece Configuration
Other areas of development have also occurred over the past 70 years with gas turbine technology. Advances in metallurgy, ceramic coatings and internal cooling designs have evolved over the past seven decades, to a point where efficiencies and higher internal firing temperatures have made the gas turbine a viable competitor to other forms of power generation. In conclusion, over sixty years ago an engineer from Britain named Frank Whittle envisioned, designed and built a multi-combustor, aero-derivative gas turbine engine for land-based applications. His innovative design in gas turbine technology has prevailed for the following six decades well into the 21st century.
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Peaking Power, Chapter 5: Gas Turbine Planes, Trains &
Automobiles
After World War II, it became popular to apply a new technology to modes of transportation including planes, trains and automobiles. The combustion (gas) turbine, under development during the war, found many commercial applications. Some succeeded; some didn‟t. Some came up against forces that crushed such innovative ideas. Planes, trains and automobiles became the focus of these applications by 1950.
Planes
From the late 1950s to today, jet-powered commercial airplanes have been a permanent presence in the skies overhead. However, entering this post-war decade, airplane manufacturers and airline companies were not anxious to go with jet-powered aviation. Jets were playing a military roll, but should they propel commercial aircraft? They consumed enormous volumes of fuel. Airport runways for civilian aircraft were too short. The capital investment required was projected to be enormous. An authoritative report by a prestigious consulting firm declared that jets could not carry the loads for long-range flight. If anything, they were perceived as a luxury for the affluent traveler. Two crashes in less than 20 months of Britain‟s Comet appeared to confirm that the world was not ready for jet-powered commercial aircraft. Turboprop aircraft was presumed to be the logical replacement for aging propeller transports.
Fig. 5-1: Jet-powered Pan Am 707 Arrived in the early 1950s
Enter the Chairman of Pan American airways, Juan Trippe, with other notions and visions. He stood alone in his perception of where commercial aviation was headed. Trippe could foresee a demand for faster transportation that carried many more passengers all over the world. Pan Am‟s main supplier of passenger aircraft at the time was a company named Douglas. They had a long-range military aircraft on the “drawing boards” that were to use Pratt and Whitney jet
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engines, but they were not large enough or powerful enough to meet Pan Am‟s needs for a profitable venture.
Trippe was not satisfied. He began courting Rolls Royce in Britain for jet engines. In his mind, there was nothing like international competition to bring Pratt &Whitney to their senses. Rolls Royce offered to sell Trippe one hundred twenty of its bigger jet engines. Armed with a commitment on engines, Trippe threatened to look abroad for engines if Douglas refused his request. Douglas reconsidered and agreed to build twenty-five DC-8 passenger airplanes. Not one to put all his “jets in one basket,” Trippe contracted with Boeing for 20 of its newly conceived 707 aircraft.
This bombshell announcement that Trippe of Pan Am had just ordered 45 jets for numbing sum of $269 Million, announced in October 1955 to a gathering of world airline leaders, shocked the aviation industry and especially Boeing. Learning that Douglas was building a larger jet, Boeing concluded it would have to build a competitive airplane and hastened to renegotiate its contract on Pan Am‟s terms. Furthermore, other airlines realized that to compete with Pan Am they too would have to invest in jet fleets too. Commercial aviation, with its a new gas turbine (jet) engines, was born. With General Electric, Rolls-Royce and Pratt & Whitney providing the power, this mode of air transportation has become an integral part of air transportation of people and cargo. However, Pan American Airlines did not survive beyond the late 1980s to see this phenomenon for other competitive reasons, but that‟s another story.
Trains
General Electric produced several models of gas turbine generators for locomotives applications in the late 1940s and 1950s. The only successful production models were sold to the Union Pacific Railroad for cargo hauling in the remote western United States. Records show that 55 turbine/generators were sold for this application.
They came in two types:
The first version was a 4,500 HP model introduced in 1949 for UP. It was called a UP50 and installed on locomotives manufactured in Schenectady, NY by American Locomotive Company (ALCO). The prime mover was a General Electric gas turbine driving a generator to provide electric power to eight traction motors. It was a dual fuel unit: starting fuel was a lighter (diesel) oil and then transferring to “Bunker C” during operation. Fuel flow was controlled by a Young & Franklin fuel regulator, described in Chapter 7 herein.
Note: In those days, Schenectady, NY was known as the “City that Powers and Moves the World.” This slogan was a tribute to the contributions and world-wide recognition of GE and ALCO in many commercial industries.
The second train model went into production in 1958. It consisted of two car bodies, a lead control unit and a second unit containing a 10,500 HP turbine. Each car body had two C trucks. At first, the two generators attached to the turbine were rated together at 8,500 HP but were later uprated to 10,000 HP.
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Fig. 5-2: Gas Turbine Powered Locomotive for Union Pacific UP50 (circa 1950)
Thirty large turbines were produced by GE and ALCO. Compared to first g,eneration of locomotives, these machines were very reliable. They burned Bunker C a thick, black oil which was considered waste fuel at the time, was initially very inexpensive. Heated tenders cars (used to keep the fuel from solidifying) were provided for each locomotive, custom made from old steam tenders. See Fig. 5-3.
Bunker C became more expensive when it became an ingredient for making plastics. Increased fuel expense doomed the gas turbine, which could not operate with the fuel efficiency of the diesel engine. A way was not yet found to cool the turbine blades like a piston engine cooling system, so the turbine had to operate at a lower, less-efficient “firing” temperatures than a diesel. Had the manufacturers invested in research and development in gas turbine cooling, as was done later in the century, the attitude toward gas turbines as prime movers in the transportation industry may have been much different.
Fig. 5-3: Turbine Tender carrying “Bunker C” Fuel
Gas turbines remained in service roughly from 1950 to 1969. None of the first generation turbines remains in operation. At least one of the second generation turbines is currently on display in Ogden, Utah.
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Fig. 5-4: Gas Turbine powered Locomotive
The 4,500 horsepower Gas Turbine Electric Locomotive (GTEL) streaked across Union Pacific rails as part of a fleet that once seemed the successor to both steam and diesel motive power. In 1954, the Union Pacific took delivery of its second order of fifteen GTEL. These new locomotives included significant improvements over their predecessors, notably roof-mounted air intakes and recessed side walkways that gave trainmen greater access to vital turbine‟s components. Because of the latter distinctively featured walkways, the new units became commonly known as Verandas. For the next decade, this style of locomotive represented the cutting edge of the Union Pacific‟s quest for horsepower for hauling more tonnage.
As a large railroad system, vast uninhabited expanses in the western states, Union Pacific constantly searched for the best means to move maximum tonnage at the highest possible speed. The UP Motive Power Department took the search a step further by squeezing maximum horsepower out of the least number of locomotives. These operating concerns led to some of the most powerful and largest locomotives ever, from the 4-8-8-4 Big Boy steamer to the DD40AX Centennial diesel. In 1948, the ultimate power solution was seen in demonstrator #100, a product of the American Locomotive Company (ALCO) and General Electric (GE). It would eventually become Union Pacific #50, the first of the only fleet of GTEL ever run on rails in the USA.
The GTEL drives a generator that, as on a diesel-electric locomotive, provides electric power to the traction motors. Initially, advantages over both steam and diesel locomotives were found in this novel power plant. With fewer parts to maintain than a diesel and cheaper Bunker C fuel oil, the turbine decreased operating costs. The GTELs generated 4,500 horsepower and the Veranda produced 137,930 pounds of starting tractive force. They pulled the same tonnage several miles per hour faster than a diesel of equal horsepower. Verandas ran double-headed with GP-9 diesels and 4-8-8-4 Big Boys to pull seemingly endless strings of heavy freight cars. Their noisy gas turbines (compressor inlet high audible whine) restricted these units from operating in highly
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populated communities. Instead, they ran on the wide open spaces of the Union Pacific system, such as along the Wyoming Division railways.
For more about this subject, go to http://www.uprr.com/aboutup/history/loco Automobiles
Following its pioneering work with jet engines during World War II, an English firm named Rover developed a gas turbine engine primarily for automobile use. The first gas turbine roadster, the Rover Jet 1, was introduced in 1951. See Fig. 5-5 below. A dozen years later, the Rover BRM ran in the 1963 Le Mans race powered by a gas turbine engine.
Fig 5-5: Gas Turbine Powered “Jet 1” by Rover (circa 1951)
The Jet-1 achieved a top speed of 152 miles per hour on a race track in England in 1951. According to the back of this photograph on a postcard, it could accelerate from 0 to 100 mph in 13 seconds. That‟s respectable performance for a “first-of-a-kind” roadster. Other cars of the era, the MGTD midget and the Triumph TR2, certainly would have had difficulty competing with this sleek beauty. A schematic drawing of the engine is shown in Fig. 5-6 below.
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Fig. 5-6: Cutaway view of automotive gas turbine engine used in the Rover Jet-1
The first competitive attempt to race a gas turbine car at Le Mans, the famous 24-hour endurance race in France, came in 1963 with the Rover BRM. It ran successfully but was too inefficient, having too high fuel consumption for this kind of racing. Two years later a regenerator was added to recover some of the lost heat from the exhaust and reduce fuel consumption. Regeneration to pre-heat the compressed air entering the combustor, made the later version very competitive as it finished 10th in the enduro race. The 1965 Le Mans car (see Fig. 5-7 and 5-8 below) overwhelmingly proved the turbine car‟s reliability and endurance capability.
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Fig 5-7: Rover BRM Gas Turbine Car at the Le Mans race of 1965
Car #31 did not win the race but it certainly left lasting impressions. Renowned driver English driver Graham Hill and diminutive American driver Richie Gunther shared the wheel in the 24-hour challenge. Fig. 5-8 shows the car during a driver change and a pit stop at Le Mans.
Fig 5-8: Pit Action for Rover BRM Gas Turbine Car at the Le Mans
The Indianapolis 500 race in 1967 had an unusual entry designed by the famous driver, Andy Granatelli. This gas turbine powered open-wheel racer was driven by the famous Parnelli Jones and had a sixth place qualifying speed of over 166 mph. Mario Andretti drove a piston engine at two miles per hour faster and won the pole position. Granatelli‟s side-mounted gas turbine engine racer led the race for remarkable 171 of 200 laps. A gear box failure, reportedly a $6 part, in the 197 lap (just 7 ½ miles from the finish) caused the STP Special from Studebaker to slip back to 6th position. It ran on Firestone tires and set 18 track records during its first attempt. Its fastest lap during the race was remarkable 164.926 miles per hour.
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Fig 5-9: 1967 STP Special Studebaker driven by Parnelli Jones (now held at the Indy Racing Museum)
According to a recent article in Pit Talk magazine by Jan Lamkins, the 4-wheel drive turbo-powered Indy car dubbed “Silent Sam” whizzed around the track with Jones at the steering wheel. The car performed magnificently, only to lose to A.J. Foyt, who won the race for the third time.
Pit Talk noted: “For 1968, USAC instituted rules that reduced the size of the turbine engine allowed. Nonetheless, Granatelli teamed with Colin Chapman and Lotus to build a wedge-shaped, 4-wheel drive Lotus 56. The STP team showed up with 3 cars, which would be driven by Joe Leonard, Art Pollard and Graham Hill. Also of note, Carroll Shelby showed up with two turbine cars that looked similar to the 1967 side-engined car. These were to be driven by Denis Hulme and Bruce McLaren. The cars practiced but were withdrawn for „safety‟ reasons.”
Imagine this, with racing legends noted above, had one of the turbine cars actually won the Indy 500, would we be driving turbine cars on the streets today? How different might the automobile industry be today if a turbine option be offered by Detroit? Could demand from the public be denied? We can only imagine. There is an old adage in car racing worth noting: What wins on Sunday, sells on Monday.
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Fig 5-10: In the pits at the 1967 Indianapolis 500 race (Courtesy of Indy Museum)
Of course, there is another unspoken axiom: if you can‟t beat them, keep changing the rules until then can‟t compete with you! More size restrictions were put on turbine car engines in the next two years. Only one turbine-powered car showed up in Indianapolis in 1969 to race. Jack Adams Special conformed to the newest restrictions in his new-look car and nearly qualified but was bumped on the final day. The qualifying agency, USAC, finally banned turbine cars (and 4-wheel drive racers) a year later. So, in the final analysis, the innovative turbine race cars, some twenty years in development, came to race at Le Mans and Indy, only to find that racing officials did not welcome them into the fold. Could the tactics of those who write the rule books, or perhaps their love for the sound of pistons engines on race tracks, have sounded the final death knell for these new turbine racers?
The gas turbine engine can be compared with a 4-cycle piston engine as shown in Fig. 5-11. The piston engine shown below is an induction stroke followed by a compression stage. Fuel is then injected, mixed with air and combusted. Expansion takes place as the piston again moves downward. The exhaust stroke follows as the hot gases are sent to the atmosphere. In the case of the gas turbine engine, air is sucked into the compressor. Once the compression takes place, the air is mixed with fuel and combusted. The hot gases then expand through the turbine section where power is developed and the gases continue to the exhaust. On some engines, a regenerator (heat exchanger) is utilized capture some of the heat and transfer it to the compressed air entering the combustor and thus reduce fuel consumption and improve cycle efficiency.
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Fig 5-11: Gas turbine cycle compared to conventional 4-cycle Automotive Engine
A few touring sedans were tried in the decade of the 1960s, but efficiency (gas mileage) soon became an issue with these non-regenerative cycle designs.
Fig. 5-12: In foreground, gas turbine powered 1956 Rover T3 Sedan in England
Meanwhile, over the Atlantic Ocean in the USA, Plymouth was building a passenger car that utilized the gas turbine engine for day-to-day use by motorists. Fig. 5-13 shows a mechanic
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working on one model. Keeping this in perspective, 1959 was the era of Sputnik and just before President John Kennedy was elected president. What if President Kennedy had challenged America, instead of sending a man to the moon in this decade, but to put a turbine-powered vehicle in every garage? How different motoring on American interstate highways have been decades later!
Fig. 5-13: Mechanic works on an American-made 1959 Plymouth sedan which had a gas turbine engine
Planes, trains and automobiles all require prime movers to propel them along. Plane manufacturers took the technology of gas turbine engines and made them the cornerstone of their prime mover fleets. Trains and automobiles, however, never embraced this innovative new engine after the 1960s. Too bad! The advances in gas turbines over the past 50 years have made this technology much more viable power source for trains and vehicles. Our lives would be better for it.
Tags: aircraft, automobiles, control systems, Gas turbine generators, gas turbines, locomotives,
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Peaking Power, Chapter 6: Rutland on the Leading Edge
Rutland, Vermont is probably not a place one would expect to be in the forefront in new technology in power generation, unless perhaps it was in mountain stream hydropower. Even less likely is this town‟s involvement with one of the first land-based gas turbines to drive an electric generator. But that is just what happened sixty years ago. In 1951, three new gas turbine plants manufactured by General Electric (GE) in Schenectady, NY were installed on the west end of Rutland, elevating this New England city to the leading edge of power technology. The owner and operator of these plants was Central Vermont Public Service (CVPS).
GE called this design combustion turbine a frame size 3. There were only ten turbines of this design ever manufactured by GE. According to their published records, all were installed in the early 1950s in such diverse locations as Maine, Texas, Connecticut and the aforementioned Vermont.
Note: The very first GE installation in power generation was at Belle Island Station of Oklahoma Gas and Electric Company was two years earlier. It was a Frame 3 but a simple-cycle, single-shaft generator drive, with the model designation 3001.
Fig. 6-1 below shows a colored cross-sectional view of the Rutland gas turbine. As depicted in the rendering, there are compressors at each end. The low-pressure (LP) axial-flow compressor is on the right; another axial-flow compressor (so called high-pressure, HP) is on the left. Air from the LP compressor is intercooled before going to the HP compressor. Air discharging from the HP compressor is then pre-heated by regenerators before going the combustors. There will be more on this later in the chapter.
Fig. 6-1: Cutaway of the 5000 KW “Kilowatt Machine at Rutland, VT
According to the CVPS unit operator log books, the first of three plants went into commercial operation on October 1, 1951. The three units were installed side by side in a building that is now an electrical repair shop for transformers, since the last gas turbine plant was retired in 1987. Unit #1 is shown in Fig. 6-2 below.
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Fig. 6-2: Elevated view of plant operators recording data on Unit #1 at Rutland, VT (circa 1951) The Rutland plants were very advanced for their time. In fact, they would be considered extraordinary even by today‟s standards. Unlike the simple-cycle, peaking gas turbine power plants that became popular in the late 1960s, in reaction to the great Northeast Blackout of 1965, these first gas turbine power plants were very complex. Dubbed the “Kilowatt Machines” by GE engineers, the indoor in power stations in Rutland were both inter-cooled and regenerative cycle. See Fig. 6-3 below. Each plant could develop approximately 5,000 kilowatts when operating at an ambient inlet temperature of 80 degrees Fahrenheit at the Rutland elevation.
Crisp and clean mountain air was sucked into the inlet of the LP compressor. The LP compressor was driven by the LP turbine stage. Air from the discharge of LP compressor was not only higher in pressure but at an elevated temperature, which hurt overall performance. GE used twin intercoolers (in parallel) to reduce the temperature at the LP compressor discharge (while maintaining the pressure) before piping it into the high-pressure (HP) compressor for further compression.
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Fig. 6-3: Cycle Diagram of the CVPS plants
The HP turbine provided the power to both the HP compressor, and through a speed reduction gear box, the AC generator. The air from the HP compressor discharged into twin regenerators. Installed in parallel to divide the airflow, the regenerators transferred heat from the turbine exhaust to the air from HP compressor discharge. This compressed and pre-heated air was then directed into the six combustors where fuel was burned adding additional heat.
Fig. 6-4: The late Norton Mark Cobb, CVPS Superintendent of Gas Turbines, kneels to take readings next to a “Kilowatt Machine” (circa 1951)
CVPS would start a plant on #2 diesel oil and later transfer to the heavier Bunker “C” fuel. The ultra-hot combustion gas, firing at 1500 degrees Fahrenheit when at base load, was then expanded through the two sections of the turbine. Approximately two-thirds of the power