An $18 million program to install a state-wide microgrid, powered by distributed gas-fired turbines, has recently been launched in the US coastal state of Connecticut, to keep the lights on in public buildings during grid outages in severe weather. The scheme comes after hurricane Sandy last year caused 5 deaths in the state, and $68 billion in damages nationwide.
The gas turbine, at first glance, appears to be a very complicated piece of rotating equipment. Part of the reason for this perception is due to the complexity and number of the various support systems involved. The accessory gearbox is a very critical piece of equipment, since it provides power take-offs to the majority of support system pumps, starters and blowers.
Americans used more natural gas, solar panels and wind turbines, and less coal to generate electricity in 2012, according to the most recent U.S. energy charts released by Lawrence Livermore National Laboratory. Natural gas use is up particularly in the electricity generation sector, where it has basically substituted directly for coal, while sustained low natural gas prices have prompted a shift from coal to gas in the electricity generating sector, according to A.J. Simon, an LLNL energy systems analyst.
Air pollution in China is a serious issue now – the nation burns roughly as much coal as the rest of the world combined. According to a study published recently in a leading U.S. scientific journal, pollution from coal has reduced the average life expectancy of northern China’s 500 million citizens by a full five years. The study, which appeared in the Proceedings of the National Academy of Sciences of the U.S., was based on data compiled between 1980 and 2000.
A gas turbine is a dynamic internal combustion engine. When we compare the performance of a gas turbine to that of a steam turbine, it becomes immediately evident that steam turbine performance is much easier to calculate, since both the vapor and the vapor conditions are fixed.
In coming years, natural gas will continue to be one of the leading fuels for power generation in Texas, but its growth as a fuel source will be dependent on a complex relationship with renewable energy resources, sources told Platts. According to the Electric Reliability Council of Texas -- which represents 85 percent of the state's electric load -- in 2012, gas accounted for almost 45 percent of electric power generation in the ERCOT region. Coal, the second most popular fuel for power generation, had about a 34 percent share, while wind had about 12 percent share.
Condensing and extraction steam turbine efficiency determination requires the calculation of the driven equipment power. This calculation can be inaccurate due to the many variables involved. Installing a torquemeter during the project phase will ensure accurate efficiency calculations for all condensing and extraction condensing steam turbines.
U.S. President Barack Obama recently said global warming is the biggest threat facing the nation and the world. In his State of the Union address in February, he asserted that "we must do more to combat climate change." His policies have been contested by some prominent scientists. Among them is Steve Goreham, Executive Director of the Climate Science Coalition of America, a non-political association focused on science and energy economics.
In June 2013, keynote speakers at PowerGen Europe in Vienna urged European governments to cooperate on a framework that would invigorate the sluggish power market. They called on policymakers to consider the "age of technologies" when deciding on sources of power to support and called for an end to "uncertain legislation-making."
Compressor degradation is the major cause of output and efficiency loss in a gas turbine. "Degradation reduces the air mass flow and pressure ratio, thus reducing power output,” said Jean-Pierre Stalder, head of new product development for Turbotect Ltd. Fouling is a major contributor of degradation. According to Stalder, it accounts for much higher losses than aging. He pointed out that enough air passes through the compressor on a 172 MW turbine in one year to make up a column that is the size of a football field, rising 1,320 miles high.
Schedule delays can prompt some vendors to offer field mechanical tests as an alternative to specified shop tests. Field testing exposes turbines to situations not encountered in FAT testing (piping and foundation stresses) which lead to decision delays and possible acceptance of less than reliable equipment.
Clean energy will be the second largest global source of electricity by 2016 after coal, according to a new report from the International Energy Agency (IEA). At its second annual Medium-Term Renewable Energy Market Report, the agency said that by the year 2016 clean energy will overtake natural gas to become the second largest source of energy in the world. Only coal will generate more electricity than clean energy within three years, the IEA projects.
Siemens Energy has completed two combined cycle power plants (CCPP) Hemweg 9 and Diemen 34 in the Netherlands. Dutch utility Nuon, a part of Vattenfall, has officially inaugurated the 440MW Hemweg 9 located in the Westport district to the west of Amsterdam's center and 435MW (260MW thermal capacity) Diemen 34 CCPP situated to the east of Amsterdam about 15km from Hemweg.
A common reliability issue with single stage steam turbines is the undetected steam seal wear and entrance of condensate into the small volume bearing housings. Steam seal wear will rapidly displace bearing oil with condensate causing Babbitt-lined, sleeve bearing wear with potentially dangerous consequences.
Turbine oil varnish has been a well-documented reliability challenge for power plants. Traditional oil analysis techniques have been ineffective at predicting the onset of deposit problems in turbine oils – often defined as varnish. This has led to the commercialization of several new analytical tests which measures oil degradation products and can be correlated to the potential of deposit formation of turbine oil. The most widely adopted test is referred to as Membrane Patch Colorimetry (MPC).
The function of the steam turbine protection system is often confused with the control system, but in fact the two systems are entirely separate. The protection system operates only when any of the control system set point parameters are exceeded, and the steam turbine will be damaged if it continues to operate. A multi-valve, multi-stage turbine protection system incorporates a mechanical overspeed device (trip pin) to shut down the turbine on overspeed (10 percent above maximum continuous speed).
Duke Energy's Edwardsport Generating Station has begun commercial operation recently. Located in Knox County, Ind., near Vincennes, the 618MW coal gasification plant uses advanced technology to gasify coal, strip out pollutants, and then burn that cleaner gas to produce electricity. The technology substantially reduces the environmental impact of burning coal to produce electric power making the plant one of the cleanest coal-fired power generating facilities.
In the previous part of this series, the author wrote about the commercial use of single shaft engines that used natural gas as fuel. In this concluding part, he reveals the surprise element – the activation of the TU 95 H for surveillance service – and explains how it compares with the jet engine-powered B-52.
In the previous article, the author discussed the unique features of the engine that became the forerunner of the J-47 jet, the F-86 fighter plane and other military planes. Here, he discusses how the early turboprop engines running on natural gas were used on commercial airplanes.
In the first part of this series, we saw how turboprop engines can be used for compressor drivers, ship propulsion and electric power, and a new railroad electric locomotive using natural gas as the fuel. In this article, the author writes about the first turboprop unit that was run using a water break.
Turboprop engines are designed with a specific integrated speed reduction gear to drive an airplane propeller whereas the turboshafts do not include a specific speed reduction gear and are generally used to power helicopters. Both are light weight and somewhat interchangeable.
Impulse bladed turbines, which historically did not produce significant thrust loads, have used reaction blades in the last three stages since the 1980s for increased turbine efficiency. The use of reaction blading in the last stages has significantly increased thrust loads – to the surprise of both end users and designers.
The 17th International Conference & Exhibition on Liquefied Natural Gas (LNG 17) took place in April at the George R. Brown Convention Center in Houston, Texas. It spread across four days and consisted of more than 50 topical sessions, panels, roundtable discussions, poster sessions and lectures.
The function of a flexible coupling is to transmit torque from the driver to the driven machine, while making allowances for minor shaft misalignment and shaft end position changes between the two machines. The design of the coupling should provide for transmission of the required torque at the required speed, with a minimum of extraneous forces and perturbations being exerted on either the driver or driven shaft. Shaft misalignment exists when the centerlines of two shafts that are joined by a coupling do not coincide.