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4
CT2 Founder ... Joseph M. Kane
PUBLICATION STAFF Publisher ... Brent Haight Associate Publisher ...Roberto Chellini Editor ...Patrick Crow Executive Editor ... DJ Slater Deputy Editor ... Mark Thayer Senior Editor ... Michael J. Brezonick Senior Editor ... Mike Rhodes Associate Editor ... Jack Burke Associate Editor ...Chad Elmore Associate Editor ...Art Aiello Copy Editor ... Jerry Karpowicz Digital Content Manager ...Catrina Boettner Advertising Manager ...Sarah Yildiz Circulation Manager ...Sheila Lizdas Production Manager ... Marisa J. Roberts Graphic Artist ...Brenda L. Burbach Graphic Artist ...Carla D. Lemke Graphic Artist ... Amanda J. Ryan Graphic Artist ... Alyssa Loope
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COMPRESSOR
A Member of the Diesel & Gas Turbine Publications GroupBrent Haight, publisher [email protected]
R
ussia has broken ground onthe Power of Siberia, a 2465 mi. (3968 km) pipeline that will link gas fields in eastern Siberia to China. The project is part of a US$400 billion deal inked in May between Rus-sia’s Gazprom and the Chinese Na-tional Petroleum Corporation (CNPC). China will begin construction of its sec-tion of the pipeline early next year.
Under the first phase of the 30-year contract, Russia will supply China 1.3 Tcf (38 x 109 m3) per year of natural
gas starting in 2018. Future phases could increase this volume to as much as 2.1 Tcf (60 x 109 m3) per year.
When complete, the Power of Si-beria will be the largest fuel network in the world, linking the Chayandins-koye and KovyktinsChayandins-koye gas fields in eastern Siberia with Khabarovsk and Vladivostok on Russia’s Pacific coast. Spurs will be drawn to China at Bla-goveshchensk and Dalnerechensk, and an LNG terminal will be built in Vladivostok. Russian President Vladi-mir Putin and China’s Vice Premier Zhang Gaoli have called the venture the world’s largest construction proj-ect, as investment from both countries will be more than US$70 billion.
This contract is Gazprom’s biggest to date and is viewed as a win/win for each country as China struggles to meet its energy demands and Russia faces growing sanctions from the west due to the ongoing situation in Ukraine.
China’s natural gas demand has been growing as the government seeks to move away from coal in favor of cleaner fuels. Last year, China con-sumed about 6 Tcf (170 x 109 m3) of
natural gas and expects to consume 14 Tcf (420 x 109 m3) per year by
2020. China’s northern and eastern provinces have growing natural gas demands that cannot be met by ex-isting pipelines or imported LNG.
Be-ginning in 2019, the Power of Siberia will pump gas from Siberia to China’s populous northeast region.
For Russia, the deal will lessen its dependence on European buyers that have imposed economic sanctions because of the Ukraine crisis. Europe still remains Russia’s largest energy market, buying more than 5.6 Tcf (160 x 109 m3) of Russian natural gas in
2013, but countries within the Europe-an Union do not mask their frustration with Russia and their desire to break free from Russia’s energy monopoly.
What remains to be seen is the im-pact the pipeline will have on natural gas prices and availability worldwide. While specific pricing details of the Russia/China deal have not been dis-closed, some energy experts warn that the deal could drive up prices for Euro-pean gas consumers who are becom-ing increasbecom-ingly dependent on Russia and now face competition for supplies.
The planned LNG terminal could pose a threat to LNG producers in Aus-tralia, Canada and Africa without con-tracts, and could undermine the U.S.’s LNG export efforts by offering better pricing to LNG-addicted countries like Japan, South Korea and India.
Taking it one step further, some analysts warn that the impact of the Russia/China deal in displacing Chi-nese LNG demand increases the likelihood of LNG oversupply.
Much uncertainly remains. What is clear is that Russian gas will remain an influencing factor in the global energy landscape, regardless of in-creased supplies and availability from rising players around the world. CT2
Russian Gas Brings
China Relief, Potentially
Pains The West
Featured Articles
16 2014 Engine Specs-At-A-Glance
18 CPI Develops Compressor Valve With Replaceable Seat Plate
34 Exterran Offers Highly Configurable Compressor Package
36 Revamp Of A Reciprocating Compressor Unit
40 2014 Year In Review
48 Cozzani’s Stepless Capacity Control Tested
54 GEA Gradually Expands Compression Range
TECHcorner
20 Combustion Solutions For Achieving Low Exhaust Emissions
In Integral Gas Compressor Engines
Departments
4 Page 4 — Russian Gas Brings China Relief, Potentially
Pains The West
8 Global Perspective — Gazprom, Ukraine Agree On Gas Sales
10 Meetings & Events
12 About The Business — Ebbing Oil Prices Erode Gas
Compressor Demand
14 Monitoring Government — North Dakota’s Flares Begin To Flicker
47 Prime Movers
56 Recent Orders
58 Featured Products
59 Literature
60 Scheduled Downtime
61 Marketplace
62 Advertisers’ Index
64 Cornerstones Of Compression — ‘Breaking The Ice’ For
Mechanical Refrigeration
December 2014
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Compressortech2 ( I S S N 1 0 8 5 - 2 4 6 8 ) Volume 19, No. 10 — Published 10 issues/year
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M
uch has been said about Russia shutting off pipe-line shipments of natural gas to Ukraine and Europe to counteract the U.S. and European sanctions. But in reality nobody has an interest in altering the sta-tus quo. Russia needs the money Gazprom collects for gas sales. Europe is its major customer. Ukraine, on the edge of bankruptcy, has problems paying Gazprom’s invoices from last winter. So at the end of the day, the parties needed to sit at a table and try to resolve their problems — and that is what happened.Russia and Ukraine have finalized an agreement that will see the resumption of natural gas supplies to Ukraine. The gas price was negotiated at US$378/1000 m3 until the end
of the year, then US$365 until the end of next March. Be-yond that, no secure deal is in place.
The accord is also dependent on Ukraine paying the first tranche of its gas arrears — US$1.45 billion — before sup-plies are restarted. The European Commission acted as a third party signatory, guaranteeing both sides would fulfill the obligations of the document, essentially ensuring Rus-sia will receive payment.
The agreement should eradicate fears of gas shortages in Europe this winter, particularly in the central and south-eastern European nations that are dependent on Ukraine as a transit route for gas deliveries. The deal also comes just in time for the start of the winter heating season, when countries begin to draw down on gas storage.
The deal is crucial for Russia and Gazprom, which have been impacted by lower revenues from the loss of the Ukrainian gas market over the summer, compounding the impact of European Union and U.S. sanctions on the ability of oil and gas companies to borrow money.
Gazprom’s profits fell in the first half of 2014 due to the lower prices it charged Ukraine over the winter — just US$285/1000 m3. Gazprom cut supplies to Ukraine
com-pletely last June, and Business Monitor International (BMI) expects its third quarter 2014 earnings to be poor.
In 2013, Ukraine was Russia’s third largest gas customer, importing over 882 Bcf (25 x 109 m3) of gas for domestic
use. BMI predicts a significant reduction in natural gas con-sumption in Ukraine due to higher prices curbing demand and the government-implemented gas savings plan. The government has introduced measures aimed at cutting gas use, including a 30% cut in consumption from the manu-facturing and municipal sectors and a 10% cut by schools and hospitals.
Due to its size, the long-term loss of the Ukrainian mar-ket would not be in Russia’s interest. The increase of gas prices from US$285 to US$365 will also mitigate any loss in revenues from reduced consumption in Ukraine. Re-gaining such a large market at an improved sales price will be a boon to Gazprom, and the Russian government especially, at a time when European gas consumption is dwindling and gas deliveries to China are still some four years from realization.
BMI’s outlook for the European gas market remains bleak, considering weak industrial growth and poor pric-ing dynamics for power generation. Currently, one can-not see anything that would change forecasts that Euro-pean gas consumption will be lower in 2023 than it was in 2006. Russia’s market share will also be challenged by Azerbaijani gas, which is expected to be flowing into southern Europe by 2019, and by increased European LNG import capabilities.
Securing the return of gas sales to Ukraine, backed by a European Commission guarantee, will be an important source of revenue for Gazprom. This will help the company support investments in its other major projects, particularly those in the Far East targeting a diversification of gas sales to China. CT2
Gazprom, Ukraine Agree On
Gas Sales >
BY ROBERTO CHELLINI ASSOCIATE PUBLISHER
Global Perspective
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DECEMBER Dec. 4-6
Shanghai International Petroleum Petrochemical Natural Gas Technology Equipment Exhibition — Shanghai Tel: +86 21 6592 9965
Web: www.sippe.org.cn/en
Dec. 4-7
Basra Oil & Gas Conference and Exhibition — Basra, Iraq
Tel: +90 21 23 56 0056 Web: www.basraoilgas.com Dec. 9-11 *Power-Gen International — Orlando, Florida Tel: +1 (918) 831-9160 Web: www.power-gen.com Dec. 10-12
International Petroleum Technology Conference — Kuala Lumpur, Malaysia Tel: +971 4 457 5800
Web: www.iptcnet.org/2014/ kualalumpur
JANUARY 2015 Jan. 20-22
Offshore West Africa — Lagos, Nigeria
Tel: +1 (713) 963-6283
Web: www.offshorewestafrica.com
Jan. 26-28
Offshore Middle East — Doha, Qatar Tel: +44 1992 656 629
Web: www.offshoremiddleeast.com
FEBRUARY Feb.15-18
*Middle East Turbomachinery Symposium — Doha, Qatar Tel: +1 (979) 845-7417
Web: middleeastturbo.tamu.edu
Feb. 18-19
*Gas/Electric Partnership Conference — Cypress, Texas Tel: +1 (713) 529-3216
Web: www.gaselectricpartnership.com
Feb. 22-25
Laurance Reid Gas Conditioning Conference — Norman, Oklahoma Tel: +1 (405) 325-3891
Web: www.ou.edu/outreach/engr/ lrgcc_home.html
MARCH March 11-13
Australasian Oil & Gas Conference —
Perth, Western Australia Tel: +61 3 9261 4500 Web: www.aogexpo.com.au
March 16-19
Nigeria Oil & Gas Conference — Abuja, Nigeria
Tel: +234 706 911 7347 Web: www.cwcnog.com
March 18-19
Turkish International Oil and Gas Conference 2015 — Ankara, Turkey
Tel: + (44) 020 7596 5000 Web: www.turoge.com
March 22-26
*Sour Oil & Gas Advanced Technology 2015 — Abu Dhabi, U.A.E. Tel: +971 2 674 4040 Web: www.sogat.org
March 23-24
*European Gas Transport & Storage Summit — Munich Tel: +44 20 7202 7690 Web: www.gtsevent.com
Meetings & Events
*Indicates shows and conferences in which COMPRESSORtech2 is participating
DECEMBER 2014 10 COMPRESSORtech2
June 9-11
*Global Petroleum Show — Calgary, Alberta, Canada
Tel: +1 (403) 209-3555
Web: http://globalpetroleumshow.com June 9-11
Sensors Expo & Conference — Long Beach, California
Tel: +1 (617) 219-8375
Web: www.sensorsmag.com/sensors-expo
June 15-19
*ASME Turbo Expo — Montreal, Que-bec, Canada
Tel: +1 (404) 847-0072
Web: http://www.asmeconferences. org/TE2015/
June 24-25
Energy Exposition — Billings, Montana Tel: +1 (307) 234-1868
Web: www.energyexposition.com JULY
July 20-22
Southern Gas Association Operating Conference — Nashville, Tennessee Tel: (972) 620-8505
Web: www.southerngas.org
possible.
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Meetings & Events
11/13/14 8:58 AMMarch 25-27
*Offshore Mediterranean Conference — Ravenna, Italy Tel: +39 0544 219418 Web: www.omc.it
March 25-26
Georgian International Oil, Gas, Infrastructure & Energy Conference — Tbilisi, Georgia
Tel: +44 207 596 5000 Web: www.giogie.com
March 26-28
*China International Offshore Oil & Gas Exhibition — Beijing
Tel: +86 10 5823 6555
Web: www.ciooe.com.cn/2014/en
March 31-April 2
Offshore Asia Conference & Exhibition — Kuala Lumpur, Malaysia
Tel: +44 (0) 1992 656 651 Web: 10times.com/offshore-asia
APRIL April 12-15
*Gas Processors Association
Annual Convention — San Antonio Tel: +1 (918) 493-3872
Web: www.gpaglobal.org
April 20-22
*Gas Compressor Association Expo & Conference — Galveston, Texas Tel: +1 (972) 518-0019
Web: www.gascompressor.org
April 27-30
*Gulf South Rotating Machinery Symposium — Baton Rouge, Louisiana Tel: +1 (225) 578-4853 Web: www.gsrms.org
April 28-30
*Gas Compressor Institute — Liberal, Kansas
Tel: +1 (620) 417-1170 Web: www.gascompressor.info
MAY May 4-7
*Offshore Technology Conference
— Houston
Tel: +1 (972) 952-9494 Web: www.otcnet.org
May 12-14
*Eastern Gas Compression Roundtable — Moon Township, Pennsylvania
Tel: +1 (412) 372-4301 Web: www.egcr.org
May 12-14
Oil & Gas Uzbekistan — Tashkent, Uzbekistan Tel: +44 207 596 5144 Web: www.oguzbekistan.com May 19-21 *Sensor+Test — Nuremberg, Germany Tel: +49 5033 9639-0 Web: www.sensor-test.de JUNE June 2-5
Caspian Oil & Gas — Baku, Azerbaijan Tel: +44 207 596 5000
Web: www.caspianoil-gas.com
June 9-11
*Power-Gen Europe — Amsterdam Tel: +44 1992 656 617
Web: www.powergeneurope.com
DECEMBER 2014 11 COMPRESSORtech2
For a complete listing of upcoming events, please visit our website at www.compressortech2.com/events/
possible.
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Compliance with environmental legislation
Increased reliability
Reduced operating costs
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Hoerbiger.indd 2 11/13/14 8:58 AM
december 2014 12 compressortech2
F
or the past four years, while natural gas prices stag-nated, strong oil and gas liquids prices have fueled growth in domestic shale development. That has driven exceptional demand for compressors, especially for gas lift, gathering and processing applications, as well as for vapor recovery.The Energy Information Administration (EIA) reported that U.S. oil production in October was at the highest level since the 1980s. It expects that U.S. shale oil production in Decem-ber will increase by 125,000 bbl/d from NovemDecem-ber. Almost all of this growth will come from the Permian Basin, Bakken and Eagle Ford plays. The Eagle Ford alone has grown 42% in the past year. The long-term growth outlook remains bullish, and Platts recently projected that the U.S. could soon sur-pass Saudi Arabia as the top global oil producer.
Meanwhile, despite less than spectacular prices, natu-ral gas production has also grown, led by the Appalachian Basin. EIA expects the Marcellus Shale flow to reach 16.04 Bcfd (4.5 x 108 m3/d) in December, with the Utica Shale
adding 1.67 Bcfd (0.47 x 108 m3/d).
This record gas production has pushed prices from above US$4.50/Mcf in the first half of 2014, down to the US$3.80 to US$4 range since August. By mid-November, New York Mercantile Exchange (NYMEX) prices appeared to be drift-ing even lower.
Sooner or later, just like the natural gas industry, oil had to recoil from its booming success. Production growth has exceeded demand, causing oil and gas liquids prices to plummet. Since early August, NYMEX West Texas Inter-mediate crude oil prices have fallen steadily from above US$100/bbl to below US$80/bbl by early November. Gas liquids prices have suffered similar declines.
As oil prices have fallen, the obvious question is: “At what price does shale oil become uneconomic to produce?” Some believe it begins at US$80/bbl; others see it as low as US$50/bbl because shale oil extraction is getting more efficient. According to the EIA, production per rig has
in-creased by more than 300% over the past four years. The International Energy Agency (IEA) estimates that about 98% of crude oil and condensate production in the U.S. has a break-even price of below US$80 and 82% has a break-even price of US$60 or lower. That may only temper the shutdown of drilling operations but it will certainly put a damper on expansion plans.
For the first time since 2010, domestic oil output is ex-pected to grow at a slower rate than the year before. Some producers, including Continental Resources, ConocoPhil-lips and Pioneer Natural Resources, have already an-nounced postponements of their 2015 expansion plans. Major oil companies, such as Chevron, ExxonMobil and Shell, are also deferring expansions and scrapping opera-tions that have narrow profit margins, according to The Wall
Street Journal.
Halliburton Chairman, President and CEO Dave Lesar opined that the crude oil market should correct itself next year. He said that shale operations are more responsive to market signals than is conventional oil production, so an oversupply can be erased more quickly. He also indicated that demand is creeping up, albeit at a lower rate.
Some Marcellus gas producers are also re-evaluating their operations because the surge in their output, which has exceeded pipeline capacity, is driving gas prices lower. For example, Cabot Oil & Gas intends to finish its pipeline projects in the Marcellus Shale and then transfer invest-ments to other fields until additional pipeline capacity be-comes available in 2017.
As it did last year, the intensity of the winter will deter-mine the near-term pricing levels for gas. Storage levels were depleted last winter and their replenishment has helped hold prices up in some regions. EIA reported that working gas storage at the end of October was still 6.2% less than a year ago and 6.8% below the five-year aver-age, despite a record summer injection of 2749 Bcf (7.8 x 1010 m3).
All the signals suggest that compressor demand has probably peaked already, and at least a temporary retreat is a certainty for 2015. How steep and how long the decline will be depends on whether oil and gas prices begin to re-cover without significant production cuts. CT2
Ebbing Oil Prices
Erode Gas Compressor
Demand >
BY NORM SHADE
About
The Business
Signals indicate equipment orders
may have peaked
BY NORM SHADE
Norm Shade is senior consultant and president emeritus of ACI
Services Inc. of Cambridge, Ohio. A 44-year veteran of the gas compression industry, he has written numerous papers and is active in the major industry associations.
Phasedown begins for burning
of wellhead gas
BY PATRICK CROWNorth Dakota’s
Flares Begin To
Flicker >
DECEMBER 2014 14 COMPRESSORtech2N
orth Dakota’s push to slash gas flaring finally is in motion.The surge in Bakken Shale oil production, which jumped from more than 230,000 bbl/d in January 2010 to more than 1.1 million bbl/d last August, has opened a flood-gate of associated gas. However, gas pipelines in the oil-prone Williston Basin are often full or far apart. Long lead times are needed to build pipeline infrastructure (see
COM-PRESSORtech2, July 2013, p. 14).
The only way for producers to sell their crude has been to burn the gas. That’s become increasingly unacceptable, most of all for a state government witnessing prospective gas royalties go up in smoke.
For the compression sector, the anti-flaring movement in the Williston Basin will create opportunities to sell packages to move the gas from the wellhead to the gathering line and on to the processing plant, which will need compression yet again.
According to the U.S. Energy Information Administration (EIA), a third of the natural gas produced in North Dakota in recent years has been flared. At times, the rate has hit 36%.
The gas is burned, rather than vented to the atmosphere, because pure methane has a much higher global warming potential than carbon dioxide, the main component of com-busted gas. The state bans gas venting.
The North Dakota Industrial Commission (NDIC) has re-ported that nearly 28% of gas output was flared last August, or 375 MMcfd (10.6 x 106 m3/d) out of a total production of
1340 MMcfd (38 x 106 m3/d). The other 72% was either sold
or used at the production site.
NDIC has established goals to decrease flaring over coming years. It set a target of 26% for the fourth quarter of this year, phasing down to 10% by 2020.
In its July 1 order, the commission pledged to reduce flar-ing even if it had to restrict the oil flow from major sources such as the Bakken Shale and the Three Forks formation. However, NDIC said it recognized the difficult economics that companies face from rapidly declining oil and gas pro-duction curves at newly drilled wells and that it would con-sider exemptions on a case-by-case basis.
The state has estimated that more than a third of flared gas results from the lack of gathering pipelines. The largest challenge there, according to the NDIC, is securing land-owner permissions, which can delay projects half a year or longer. Other obstacles include zoning and permitting de-lays, harsh weather and labor shortages.
The remaining two-thirds of flared gas is due to the chal-lenges of altering existing infrastructure, such as the need for additional pressure on gathering lines to offset the high-er pressure from newly drilled wells and increased pipeline capacity from high-pressure wells.
Another challenge is the necessity to strip more liquids from the wet gas before it enters trunk lines. EIA said by the end of the year, new gas processing plants in the state would boost capacity to 1.454 Bcfd (41.1 x 106 m3/d), or
440 MMcfd (12.5 x 106 m3/d) more than last year. There
are plans to build another 400 MMcfd (11.3 x 106 m3/d) of
processing capacity by the end of 2016.
Even that won’t be enough. As the Bakken oil wells mature, they will yield less crude but proportionately more liquids-rich gas. The state has estimated the gas processing need may grow to 2.5 Bcfd (70.8 x 106 m3/d) within 10 to 15 years.
NDIC said the Fort Berthold Indian Reservation — home to the Mandan, Hidatsa and Arikara tribes — is a major part of the gas-flaring problem. Last August, 35.5% of gas pro-duced on the reservation was burned. The rate peaked at 64% in 2011.
The reservation produces roughly a third of North Dako-ta’s oil. Last August the flow was more than 333,000 bbl/d, of which 134,000 bbl/d was from tribal lands and 199,000 bbl/d from private lands. If the reservation were a separate state, it would be the nation’s seventh largest oil producer.
The Three Affiliated Tribes organization has said that construction of gathering lines, processing plants and trunk lines has been complicated by the overlap of governmen-tal rules. State regulators insist that their flaring regulations apply even on tribal lands. The tribes are developing their own approach, and the U.S. Department of the Interior is drafting its own flaring rule for federally managed lands. CT2
Monitoring Government
NEAC Compressor Service Ltd.
Located in Rayong, Thailand
www.neac.net
Contact me for South East Asia:
Teerawat Kijsawas
Senior Technical Service Engineer
[email protected]
Direct Phone: +66-38-923713
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Daihatsu
Dresser-Rand
Electro-Motive
Diesel (EMD)
Fairbanks Morse
GE Power & Water,
Distributed Power
Guangzhou
H. Ceglielski –
Pozna´n S.A.
Hyundai Heavy
Industries
Jinan
20,000 19,000 18,000 17,000 16,000 15,000 14,000 13,000 12,000 11 ,000 10,000 9000 8000 7000 6000 5000 4000 3000 2000 1900 1800 1700 1600 1500 1400 1300 1200 1100 1000MAN Diesel & Turbo
Maschinenbau
Halberstadt
Mitsubishi Heavy
Industries Marine
Machinery & Engine
Mitsubishi Power
Systems Americas
Moteurs Baudouin
MTU
Friedrichshafen GmbH
MWM
Niigata
Perkins
Rolls-Royce
Rumo
Wärtsilä
Yanmar
20,000 19,000 18,000 17,000 16,000 15,000 14,000 13,000 12,000 11 ,000 10,000 9000 8000 7000 6000 5000 4000 3000 2000 1900 1800 1700 1600 1500 1400 1300 1200 1100 1000KILOWATTS
Diesel or Heavy Fuel
Gaseous Fuel
Dual Fuel
1000 to 5200 1000 to 2670 31 to 16,226 71 to 6100 8 to 16,000 41 to 6729 37 to 3281 172 to 2000 66 to 6600 66 to 6600 170 to 1465 150 to 1350 288 to 768 1249 to 3729 750 to 23,850 1255 to 18,000 120 to 9500 660 to 4400 660 to 1080 500 to 30,000 575 to 10,000 15,000 to 25,000 455 to 880 2880 to 9600 2880 to 4320 10 to 6300 400 to 1000 450 to 87,220 548 to 2061 1740 to 87,220 1740 to 87,220 75 to 10,000 200 to 2530 400 to 4300 30 to 4000 1350 to 35,520 1350 to 35,520 3760 to 15,400 3650 to 5500 60 to 883 500 to 13,768 1007 to 6032 4 to 2000 322 to 1042 1685 to 12,000 1425 to 9620 800 to 4224 800 to 1045 800 to 1000 2700 to 80,080 4320 to 19,260 4050 to 17,550 250 to 3530 300 to 2000
KILOWATTS
December 2014 16 compressortech22014 ENGINE
CT501_Specs.indd 1 11/19/14 10:33 AMDiesel or Heavy Fuel
Gaseous Fuel
Dual Fuel
ABC –
Anglo Belgian Corp.
Caterpillar Global
Petroleum
Caterpillar Marine
Power Systems
Cummins
Daihatsu
Dresser-Rand
Electro-Motive
Diesel (EMD)
Fairbanks Morse
GE Power & Water,
Distributed Power
Guangzhou
H. Ceglielski –
Pozna´n S.A.
Hyundai Heavy
Industries
Jinan
20,000 19,000 18,000 17,000 16,000 15,000 14,000 13,000 12,000 11 ,000 10,000 9000 8000 7000 6000 5000 4000 3000 2000 1900 1800 1700 1600 1500 1400 1300 1200 1100 1000MAN Diesel & Turbo
Maschinenbau
Halberstadt
Mitsubishi Heavy
Industries Marine
Machinery & Engine
Mitsubishi Power
Systems Americas
Moteurs Baudouin
MTU
Friedrichshafen GmbH
MWM
Niigata
Perkins
Rolls-Royce
Rumo
Wärtsilä
Yanmar
20,000 19,000 18,000 17,000 16,000 15,000 14,000 13,000 12,000 11 ,000 10,000 9000 8000 7000 6000 5000 4000 3000 2000 1900 1800 1700 1600 1500 1400 1300 1200 1100 1000KILOWATTS
Diesel or Heavy Fuel
Gaseous Fuel
Dual Fuel
1000 to 5200 1000 to 2670 31 to 16,226 71 to 6100 8 to 16,000 41 to 6729 37 to 3281 172 to 2000 66 to 6600 66 to 6600 170 to 1465 150 to 1350 288 to 768 1249 to 3729 750 to 23,850 1255 to 18,000 120 to 9500 660 to 4400 660 to 1080 500 to 30,000 575 to 10,000 15,000 to 25,000 455 to 880 2880 to 9600 2880 to 4320 10 to 6300 400 to 1000 450 to 87,220 548 to 2061 1740 to 87,220 1740 to 87,220 75 to 10,000 200 to 2530 400 to 4300 30 to 4000 1350 to 35,520 1350 to 35,520 3760 to 15,400 3650 to 5500 60 to 883 500 to 13,768 1007 to 6032 4 to 2000 322 to 1042 1685 to 12,000 1425 to 9620 800 to 4224 800 to 1045 800 to 1000 2700 to 80,080 4320 to 19,260 4050 to 17,550 250 to 3530 300 to 2000
KILOWATTS
December 2014 17 compressortech2specs-AT-A-GLANce
CT501_Specs.indd 2 11/19/14 10:34 AMC
ompressor Products Interna-tional (CPI) has developed a compressor valve with a re-placeable seat plate for quick recon-ditioning in critical operations or in re-mote/hazardous environments.The Hi-Flo RS valve is a refine-ment of the company’s Hi-Flo R and V valves.
CPI noted that unscheduled recip-rocating compressor shutdowns can lead to costly production losses.
Compressor valves have many active parts and are responsible for more unscheduled shutdowns than any other compressor component.
When a valve fails, it not only reduces efficiency and capacity but also can result in secondary damage to other parts of the compressor.
CPI said its Hi-Flo R radius valves have performed reliably in the oil, gas petrochemical and air separation in-dustries worldwide.
The radiused profile of the valve
rings (Figure 1), which control and seal the process gas as it flows into and from the compressor cylinder, provides several important characteristics.
The main advantage is that the Hi-Flo R valves provide very long running times, typically up to three years between planned maintenance and overhauls. This is an advantage when service or reconditioning — re-quiring specialized skills, equipment and facilities — are needed for com-pressors that are operating in remote or difficult environments.
When an overhaul is needed, valves are shipped to a CPI facility or an approved workshop, resulting in downtime that costs time and money.
CPI developed the Hi-Flo RS valve at the request of a customer who oper-ated compressors using Hi-Flo V and R valves on offshore production plat-forms, floating production, storage and offloading vessels and other facilities far from properly equipped mainte-nance workshops.
The Hi-Flo RS has a replaceable seat plate that is integrated into the valve seat housing. Over time, any normal wear will be on the seat plate rather than on the valve seat itself.
CPI Develops Compressor
Valve With Replaceable
Seat Plate >
Designed for critical operations, remote/
hazardous environments
n CPI developed this replaceable seat compressor valve to simplify overhauls.
December 2014 18 compressortech2
n
Figure 1: This drawing shows the profile for the Hi-Flo R valve.n
Figure 2: This is a finite element analysis of the new seat plate in PEEK.When valve efficiency begins to decline, the seat plate can be popped out and a new seat plate can be snapped into place.
Because the new seat plate has the same dimensions as the original, there is no need for complicated depth and clearance adjustments, using shims and gaskets, when re-installing the valve.
The seat plate is made of polyetheretherketone (PEEK), the same rugged and durable material used to manufacture the rings. The difference in the strength of the replaceable PEEK seat plate compared to a traditional seat is negligible, as proven by engineering studies (Figure 2) and field tests.
CPI said the Hi-Flo RS valve performs extremely well un-der severe operating conditions and for processing of gases that contain liquid slugs and debris. Figure 3 shows the good condition of a valve removed preventively after 13 months of operation on a gas lift three-stage compressor offshore.
Total E&P Congo, equipped all stages of its PAC4 com-pressors with this technology in 2012 and is preparing to equip a General Electric Nuovo-Pignone 6HM3 with the technology by the end of 2014.
“The CPI Hi-Flo RS is the response to our problems. We don’t need to re-machine or use special tooling for mainte-nance,” a Total E&P representative said.
“Furthermore, we don’t need to keep complete valves in stock — only rebuild kits. We have also reduced the un-scheduled shutdown time and some valves installed two years ago are still running.”
The company said the new valve could be completely reconditioned on location without specialized tools, re-ma-chining, presses or other equipment. The rebuild kit includes the replaceable plate, new valve rings, springs and buttons.
CPI said since there is no reduction in valve seat thick-ness, no adjustments are needed if unloader forks are fitted on the suction valves. CT2
December 2014 19 compressortech2
n
Figure 3: This clean valve came from a third-stage gas lift com-pressor in service offshore.Recognized
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www.r-f.com [email protected] Tulsa, OK ReynoldsFrench.indd 1 7/8/13 2:07 PM CT487.indd 2 11/19/14 9:01 AMDavid Lepley has a bachelor’s degree in electrical
engineer-ing from Youngstown State University. He is Product Manager – Ignition Systems for Altronic, with responsibility for devel-oping and promoting advanced ignition technologies for gas engines. Luigi Tozzi has a doctorate in mechanical engineering from the University of Naples, Italy. His emphasis has been on lean burn gas engine combustion since the early 1980s. As president of Prometheus Applied Technologies, he leads the development and commercialization of precombustion cham-ber systems for large lean burn gas engines. Emmanuella
Soti-ropoulou has a master’s in electrical engineering from Colorado
State University. As vice president at Prometheus Applied Technologies, she is in charge of the development of precom-bustion chamber systems for large lean burn gas engines. This paper was presented at the Gas Machinery Research Conference in Albuquerque, New Mexico, in October of 2013.
Combustion Solutions For Achieving
Low Exhaust Emissions In Integral Gas
Compressor Engines >
O
perators of lean-burn natural gas engines are con-stantly striving to meet emissions requirements in the most cost effective way possible. More specifi-cally, the conversions of legacy large-bore (greater than 9.8 in. [250 mm]) natural gas engines can easily reach in ex-cess of US$100,000.This approach still provides some cost savings over a new engine installation, but is no longer necessary thanks to recent breakthroughs in high-energy ignition systems and the design of passive prechamber plugs via the use of computational fluid dynamics (CFD) [1-6].
This paper provides a summary of the advancements made in the past year by coupling emerging technologies such as the high-energy ignition and passive prechamber spark plug technologies and applying them to large-bore gas engines.
Two different configurations are covered. The first is the combination of the high-energy ignition technology with the passive prechamber spark plug in an open-engine com-bustion chamber configuration. The second is the same combination but this time the passive prechamber spark plug is located inside a fuel-fed precombustion chamber and referred to as the “dual-stage prechamber”
technol-ogy (patent pending). Both combinations have achieved in-cremental reduction in exhaust emissions with large-bore, slow-speed natural gas engines. The engine results of both of these combinations have been previously published [7].
In this paper, the continuation of the technology validation of the combination of the high-energy ignition and the dual-stage prechamber technology will be presented in terms of the com-plete engine test on an integral gas compressor engine.
While the dual-stage prechamber technology described in this paper was tested on a legacy integral gas compres-sor engine, the concept is also believed to be applicable to newer, high brake mean effective pressure (BMEP), large bore two-stroke or four-stroke engines. The paper merely intends to present the potential of this technology and calls for the next step of generating specific production solutions to address the industry’s needs.
The information in the following section has been pub-lished previously [7] and is presented to provide an adequate foundation for the new results presented later in this paper.
Engine system configuration
The authors decided to model and test the solutions proposed in this paper on a representative large-bore gas engine residing at the Engines and Energy Conversion Laboratory at Colorado State University. It is a four-cylinder Cooper Bessemer GMV-4TF with in-cylinder fuel injection. Figure 1 shows the engine installation. Table 1 contains the specifications of the engine as tested.
Each cylinder of this engine can be configured in two ways. One way is to use two spark plugs per cylinder. The other way is to use a precombustion chamber, which has its own separate fuel line. The fuel admission into the precombustion chamber is controlled by a mechanical check valve. For the purposes of the test, an electronic fuel control valve (ePCC [8], Figure 2) was installed, which is able to control the admis-sion timing and fuel amount in the precombustion chamber. This electronic fuel-control valve allows to deliver the fuel in the under sonic conditions.
TECHcor
ner
December 2014 20 compressortech2
Passive prechamber, dual-stage
prechamber methods explored
By DaVID LEPLEy, LUIGI TOzzI anD EMManUELLa SOTIrOPOULOU
continued on page 22
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December 2014 22 compressortech2
The specific advantages resulting from using an electron-ic fuel control valve compared to a mechanelectron-ical check valve have been discussed in a previous publication [9] and are not addressed in this paper. However, the need to use this type of fuel delivery system in this study was mainly to con-trol the fuel amount delivered independently of the cylinder pressure during the time of admission.
n
Figure 2. The ePCC electronic fuel control valve and CPU-XL ignition system on engine installation.The engine is outfitted with the latest available ignition system technology as shown in Figure 2. A tunable, high-energy ignition system able to assure reliable ignition with lean air-fuel mixtures, while maintaining long plug life, was selected for this test [1].
This system was chosen because it allows the user the flexibility in selecting a spark waveform profile based on the flow velocity at the spark plug gap, which is determined with the help of CFD for a particular application. The specific
advantages resulting from using this ignition system com-pared to a conventional system are the subject of a previ-ous publication [10].
Combustion pressure transducers are installed in all four cylinders, allowing for high-speed combustion pressure measurements via a high-speed data acquisition system (HSDA). The HSDA was controlled by a National Instru-ments PXI-1002 system.
The software computed combustion parameters such as peak cylinder pressure and location, heat release rate, in-dicated mean effective pressure (IMEP) and cycle-to-cycle variations. It was possible to monitor exhaust gas emis-sions of the entire engine.
The five-gas analyzer used for the test was a Rosemount five-gas emissions analyzer that measures CO, CO2, THC,
NOx and O2 concentrations. Both measuring systems are
shown in Figure 3.
n
Figure 3. The data-acquisition equipment (left) and the gas-analyzer rack.The engine air-fuel ratio is controlled by independently setting the air mass flow rate and the fuel mass flow rate. The engine is configured to maintain a constant differential pressure of 17.2 kPa (2.5 psi) between intake and exhaust. The air mass flow rate is controlled by adjusting the back-pressure. A variable-speed Roots blower is used to supply air to the engine and a variable-exhaust restriction is used to control the backpressure and to simulate a turbocharger.
Passive prechamber spark plugs for open chamber configuration
In the first combination of the high-energy ignition system and prechamber plugs, the two conventional spark plugs in the open chamber engine configuration are replaced with passive prechamber spark plugs. The plugs are located in the 0° loca-tion and the -45° localoca-tion as shown in the model of Figure 4.
CFD analysis indicated that a relatively large variation in the mixture distribution is to be expected in the two loca-tions with a lambda of 1.75 (f = 0.571) in the 0° location
RPM 300
Bore (mm) 356
Stroke (mm) 356
CR 10
continued on page 24
n
Figure 1. The Cooper Bessemer GMV-4TF at the EECL-CSU.n
Table 1. The Cooper Bes-semer GMV-4TF as tested at the EECL-CSU.Machinery uptime is at your fi ngertips
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and a lambda of 2.35 (f = 0.426) in the -45° location. This was observed at the time of spark of 5 crank angle degrees (CAD) before top dead center (BTDC). The results are shown in Figure 5.
n
Figure 5. The lambda distribution of the two spark plug locations [7]. Due to the large variation in lambda distribution observed in the CFD results, the two designs shown in Figure 6 were developed. The prechamber plug designs were able to suc-cessfully trap some fuel during the direct injection event to provide a richer environment than the conventional spark plug for the initial flame development.n
Figure 6. These are the two passive prechamber plug designs. The CFD results of the prechamber plug designs are shown in Figure 7 as compared to the open spark plug (J-gap type). The mixture at the gap of the open spark plug is 1.55 (f = 0.645) while that of the prechamber plug is 1.25 (f = 0.800) with an even richer mixture surrounding it (l=1.15, f = 0.870) to ensure strong flame jet formation.n
Figure 7. The lambda comparison at the electrode gap region between the two spark plugs [7].The results of the initial flame development initiated from two different spark locations for both the conventional open plug and the prechamber plug are shown in Figure 8. The
conventional spark plug (left) and the prechamber plug (right). Comparison of initial flame development from two different spark locations (isothermal surface at 1500K) [7]. The flame is represented as an isothermal surface at 1500 K, seen in red. These results indicate that the use of the prechamber plugs on engine will improve engine stability and, hence, ex-tend the lean flammability limit. This was later confirmed by the engine test at a constant load of 500 hp (372 kW).
n
Figure 8. The conventional spark plug (left) and the prechamber plug (right). Comparison of initial flame development from two dif-ferent spark locations (isothermal surface at 1500K) [7].The results indicated that the bullet prechamber plug de-sign provided the most stable operation as seen in Figure 9. The engine stability, measured as the coefficient of varia-tion of indicated mean effective pressure (COV of IMEP) versus NOx emissions is improved by more than a factor of
2 at less than 2 g/bhp-hr operating conditions.
Further improvements in the stability at lean operating points are made by the use of the high-energy ignition sys-tem. In conclusion, these results indicate that the combina-tion of passive prechamber spark plugs and the high-energy, tunable, ignition system provide the most robust solution for the 500 mg/Nm3 (1 g/bhp-hr) operation for large-bore
natural gas engines.
n
Figure 9. The COV of IMEP vs NOx and excess air ratio (l=1/f) forthe three configurations [7].
December 2014 24 compressortech2
continued on page 26
n
Figure 4. The rela-tive location of the two spark plugs is shown.A
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Dual-stage precombustion chamber concept
In order to improve the efficiency and emissions trade-off obtained by the standard precombustion chamber, a second concept was developed. Here, the reduction in emissions is obtained by reducing the fuel present in the precombustion chamber. To ensure consistent flame propagation within the now lean, homogenous precombustion chamber, flame jet ignition must be utilized.
To address this problem, the “dual-stage prechamber” ap-proach was created and is currently patent pending. Here, the combination of a smaller, fuel-rich prechamber (first stage) inside a larger, fuel-lean prechamber (second stage), are used to initiate the combustion in the main chamber.
This combination leads to a reduction in the NOx
pro-duction compared to the conventional configuration. To achieve the desired distribution in the dual-stage preber and appropriate flame jet penetration in the main cham-ber, a new design had to be developed for the second stage (Figure 10) to be coupled with a passive prechamber spark plug that served as the first stage. In addition, the fueling of the prechamber was controlled by an electronically actu-ated sonic valve as opposed to a mechanical check valve.
It is important to note that the use of the timed fuel deliv-ery was done to prove the ability of this approach to reduce emissions while increasing efficiency. Once this technology proves sound, a development process will be necessary to fit this approach in meeting different application needs, such as the combination of the dual-stage prechamber with the use of a mechanical check valve.
Comparative CFD analysis of the baseline conventional configuration (fuel-fed precombustion chamber with con-ventional spark plug) and the new dual-stage prechamber approach is shown in Figure 11. As expected, the conven-tional configuration is overly rich at approximately l=0.85 (f= 1.18) while the dual-stage prechamber has a lambda of 1.5 in the second stage and 1.2 in the first stage.
n
Figure 11. The lambda distribution in the conventional precham-ber (left) and dual-stage prechamprecham-ber (right) [7].Ignition is initiated in the passive prechamber spark plug,
which receives its fresh air-fuel mixture during compression from the first stage. The ensuing flame jets from the passive prechamber spark plug initiate combustion in the fuel-fed second stage, which in turn initiates combustion in the main chamber. The combustion simulation of Figure 12 demon-strates this combustion sequence.
n
Figure 12. The dual-stage prechamber/flame jet development (isothermal surface at 1500K) [7].Dual-stage precombustion chamber concept — full engine test
The first step for proving this technology was to perform an engine test in which one of the four cylinders of the Cooper Bessemer GMV-4TF was outfitted with the new dual-stage prechamber approach. The results from this test were pub-lished in a previous publication [7]. Due to the promising results of the single cylinder test, a full engine test was performed.
The baseline (conventional configuration) used the me-chanical check valve for the fuel admission in the precom-bustion chamber. In the case of the dual-stage prechamber, as described previously, all prechamber fuel lines were in-stalled with electronic fuel control valves.
This was done as an expediency to proving out the dual-stage prechamber technology. The fuel admission by these valves was kept under sonic conditions throughout the du-ration of the test. Future plans include the development and application of the dual-stage prechamber with the use of a mechanical check valve.
The test was performed at two different load conditions to gain an understanding of the behavior of the new technol-ogy under different engine power ratings; 500 hp (373 kW) and 350 hp (260 kW). The spark timing selected for the baseline is the optimum timing for this engine configuration and is set to 3 CAD BTDC.
To better characterize the performance of the dual-stage prechamber concept, three different spark timings were in-vestigated during the test: 3, 5 and 8 CAD BTDC. For each timing, the air manifold pressure was increased to reduce the fuel injected in the main chamber and achieve leaner in-cylinder conditions. No attempt was made to optimize the timing of the electronic fuel admission valve of the second stage. Following are the comparative results of the baseline and the dual-stage prechamber concept (DS).
December 2014 26 compressortech2
continued on page 28
n
Figure 10. The original precombustion cham -ber hardware compared to the new design of the dual-stage prechamber technology.Our Best
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The most comprehensive picture of the combustion re-sults is shown in Figure 13 in terms of the trade-off between brake thermal efficiency (BTE) and brake specific (BS) NOx
emissions at 500 hp. All spark timings of the dual-stage pre-chamber produce a higher BTE with lower NOx emissions
compared to the baseline.
At 0.75 g/bhp-hr of BS NOx emissions, the efficiency gain
ranges from approximately 0.5% points to 1.5% points. It was expected that the dual-stage prechamber would require more advance timing than the baseline due to the leaner sec-ond stage and to the time delay introduced by the first stage. The dual-stage prechamber achieves a BTE range be-tween 30.6 and 31.8% at 0.5 g/bhp-hr. It was not possible to obtain any data points at leaner than 0.35 g/bhp-hr because the engine had reached the airflow limit.
n
Figure 13. The 500 hp BTE/NOx trade-off comparison of thecon-ventional precombustion chamber (baseline) and the dual-stage prechamber.
The improved trade-off between BTE and NOx emissions
can be attributed mostly to the leaner conditions occurring in-side the second stage and to the enhanced flame propagation resulting from the flame jet ignition of the rich first stage. It can be further confirmed by comparing the mass of fuel in the second stage at 4.85 mg per injection to that of the baseline at 20.2 mg per injection (approximately 76% reduction in fuel).
Another contributing factor for this gain in efficiency is the increased engine stability due to the more efficient design of the second stage producing three flame jets instead of one (Figure 10), increasing the main chamber turbulence and, therefore, flame propagation. The engine stability is measured in terms of the coefficient of variation of indicated mean effective pressure (COV of IMEP). A comparison be-tween the baseline and the dual stage is shown in Figure 14. The results indicate that the baseline has an acceptable COV of IMEP of less than 5% at NOx levels higher than 0.75
g/bhp-hr. In contrast, the dual-stage prechamber is able to operate at a comparable COV of IMEP of less than 5% at a NOx level of less than 0.4 g/bhp-hr and is limited by the
engine’s airflow limit. Another observation can be made at the same emissions of 0.75 g/bhp-hr, where the dual-stage
prechamber improves the COV of IMEP from 4.75 to 2.2%. A comparison of the combustion pressure for the two points indicated in Figure 13 is provided in Figure 15 for all four cylinders. These two points were selected at similar COV of IMEP and have approximately 1% point difference in BTE.
It is easy to see the difference in manifold air pressure as indicated by the two black arrows. Even though the dual-stage prechamber is running at leaner conditions, it is able to produce higher peak pressures leading to higher efficiency.
n
Figure 15. The 500 hp combustion pressure comparison for baseline (dotted line) and dual-stage prechamber(solid).Taking a look at the BTE/NOx trade-off of the 350 hp power
rating, shown in Figure 16, one can see that the dual-stage prechamber technology offers more stable operation at 0.5 g/ bhp-hr of NOx emissions with approximately 1.0% point in
effi-ciency gain. Further insight into the engine stability is shown in Figure 17 where the baseline maintains an acceptable opera-tion (COV of IMEP < 5%) at a NOx emissions level of
approxi-mately 0.6 g/bhp-hr, while the dual-stage prechamber achieves the same at a NOx emissions level of less than 0.3 g/bhp-hr.
These results confirm that the benefits of the dual-stage pre-chamber are maintained at lower engine power ratings.
December 2014 28 compressortech2
continued on page 30
n
Figure 14. The 500 hp combustion stability comparison.Insight onsite.™
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Figure 16. The 350 hp BTE/NOx trade-off comparison.n
Figure 17. The 350 hp combustion stability comparison.Conclusions and next steps
This paper is a continuation of a previous study published in the 2013 CIMAC congress. The study was possible thanks to recent significant advancements in CFD com-bustion technology and high-energy ignition system tech-nology. Two cost-effective approaches are investigated for their ability to reduce emissions in large-bore natural gas engines (greater than 250 mm).
The first is the use of two passive prechamber spark plugs in place of the conventional spark plugs (J-gap type) in an open chamber engine configuration. This approach was able to reduce the NOx emissions level to 1 g/bhp-hr
while maintaining good combustion stability (COV of IMEP less than 5%).
To provide further improvements to the efficiency and emissions trade-off of engines configured to use a fuel-fed precombustion chamber, the second approach investigated is the use of a dual-stage prechamber (patent pending).
Here, the existing, fuel-rich conventional precombustion chamber and spark plug are replaced with the combination of a small fuel-rich prechamber (first stage) inside a larger, leaner prechamber forming the dual-stage prechamber. Both stages are especially designed to function together.
Combustion of the leaner mixture inside the second stage is initiated by flame jets produced by the first rich stage.
In this paper, a full engine test is performed to determine the merit of this new technology. The engine used is a Coo-per Bessemer GMV-4TF with four cylinders that are all instru-mented. The results of the test validate the expectations set forth by a previously published single cylinder test, showing a reduction in NOx emissions much below 0.5 g/bhp-hr while
gaining 1.5% points in BTE at a 500 hp engine rating. Fur-thermore, this approach demonstrated great improvements in combustion stability at lower engine ratings (350 hp).
Both approaches presented in this paper provide a flex-ibility of choice to the operator in meeting emissions require-ments in a more cost effective way. The dual-stage precham-ber approach has demonstrated large gains over the present state of the art, warranting the continuation of developing application specific solutions. The immediate next step is the development of an optimized dual-stage prechamber config-uration that allows retrofitting of integral compressor natural gas engines that use precombustion chamber fuel admission systems with subsonic check valves. This development will be the subject of a subsequent publication. CT2
References
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