A New Era for Natural Gas Turbines

A New Era for Natural Gas Turbines A New Era for Natural Gas Turbines Many older, decommissioned coal power plants are being replaced with highly efficient natural gas turbines. In someplaces where fuel is imported, such as in Europe and Asia, highly efficient turbines are critical for power plants to continue operations because of high fuel costs. In the U.S., where natural gas prices are lower, highly efficient natural gas turbines are not only being selected as replacements for their cost savings, but also for their ability to meet stricter ambient effektenemission regulations. Twenty years ago, land-based electrical power gas turbine (GT) efficiencies crept upward from 15%, as E-class turbines matured into F-class. A decade ago, turbines were approaching combined-cycle efficiencies of 50%. The large, high-capacity G, H, and J class electrical GTs of today produce hundreds of megawatts of power. Used in combined-cycle power plants along with heat-recovery steam generators and stea m turbines, they can achieve greater than 60% combined-cycle efficiency. Large GT manufacturers have taken different approaches to increasing efficiency, including increasing overall mass flow, increasing compressor pressure ratio, and increasing the temperature of the air entering the turbine. The latter, increasing the firing temperature, is the most common and most technically challenging. Natural gas turbines are not only being used as replacements because of their cost savings but also for their ability to meet stricter ambient regulations. Hotter Is Better As the temperature of the air entering the turbine has increased to be higher than the melting point of some of the materials that come in contact with hot gases inside the turbine, manufacturers have not only had to develop specialty turbine blade materials, but also new blade designs, coatings, and cooling technologies specifically to enable robust, reliable operations at these ultra-high temperatures. According to Carlos Koeneke, vice president of project engineering and quality assurance at Mitsubishi Heavy Industries, many of these types of advancements have led the way for operation at turbine inlet temperatures of 1,600 degrees C, achieved during the last year. The biggest challenges with increasing the temperature were the materials exposed to the hot gases, which have historically limited the temperature in the past,he says.Were getting to the point where we cant further improve the materials, and are now using thermal barrier coatings as facilitators. Also, internal cooling is now needed, which steals some energy from the system but enables operatio. As a result of higher firing temperatures, mega turbines not only produce higher amounts of power, but higher power density as well, so fewer turbines are needed to generate the same amount of power. On a dollar-per-kilowatt/hourbasis, the price is lower for mega turbines, since power plants actually spend less in construction, footprint, and ins tallation. Increased Flexibility Despite having high efficiency, these new GTs in combined-cycle power plants are challenged when it comes to operating efficiently under variable loads. Flexibility, which can refer to the ability to start and stop frequently or rapidly, is becoming mora important as more generating plants receive power from sources such as wind and solar. Achieving high efficiency in a combined-cycle plant requires operation at constant base loads or at full load, or peak operating conditions. Its not that long times are needed to achieve high efficiency, but they dont react well to big changes, Koeneke says. Single-cycle GT systems that are faster to react are now able to operate more efficiently when parked at lower loads, and are also maintaining emissions compliance over wider load ranges. Some power plants are adopting multiple systems, both combined and single mode, for more flexible operations, since a single system cannot perform well in both modes. Efficien cy has long been the goal in designing and operating gas turbines. Having achieved greater than 60% efficient emissions-compliant operation, the new-era turbines are entering what could be referred to as flexible efficiency, as the focus shifts toward the ability to adjust to new types of demands for efficient operations. Debbie Sniderman is a consultant, an engineer, and a contributing writer to Mechanical Engineering.The biggest challenges with increasing the temperature were the materials exposed to the hot gases, which have historically limited the temperature in the past.Carlos Koeneke, vice president of Project Engineering and Quality Assurance, Mitsubishi Heavy Industry

In Iceland, its now illegal for men to be paid more than women

In Iceland, its now illegal for men to be paid more than womenIn Iceland, its now illegal for men to be paid more than womenIn Iceland, its no longer enough to say youll offer equal pay - youll need to prove it.As part of its ambitious goal to completely end the gender wage gemeinsame agrarpolitik within the next five years, Iceland has made it illegal for men to be paid more than women, reportedly becoming the first country in the world to make public and private employers prove they offer equal pay to men and women for equal work. The new law, which was announced on International Womens Day in March, went into effect on January 1st.Under the law, companies employing 25 people or more will undergo audits and must get a certification from the Icelandic government that proves their compliance with equal-pay policies, or else they will be fined.Iceland Where closing the gender wage gap is now legally enforcedIceland, which has a population of fewer than a million people, is already at the forefront of the movement toward workplace gender equality. The World Economic Forum named Iceland the most gender-equal country in the world for the ninth year in a row, notlageing that it has closed more than 70% of its gender gap in political empowerment. The annual gender progress report, which examines the gender gap in four areas - economic participation and opportunity, educational attainment, health and survival, and political empowerment - noted that since it first was released in 2006, Iceland has closed approximately 10% of its total gender gap, making it one of the fastest-improving countries in the world. But even though they have made rapid progress, government officials and advocates see legalization of their standards as a necessary step to ensure enforcement.We want to break down the last of the gender barriers in the workplace, Thorsteinn Viglundsson, Icelands social affairs and equality minister, told the Times when the law was first announced. History has shown that if you want progress, you need to enforce it.Dagny Osk Aradottir Pind, a board member of the Icelandic Womens Rights Association, told Al Jazeera, that enforcement is needed to move the issue beyond awareness Women have been talking about this for decades and I really feel that we have managed to raise awareness, and we have managed to get to the point that people realize that the legislation we have had in place is not working, and we need to do something more, she said.

5 tips to picking out the perfect office chair

5 tips to picking out the perfect office chair5 tips to picking out the perfect office chairIt is always important to pick an office chair that suits you. Yeah, that comes without saying right? Sitting for long periods of time slaying in an uncomfortable chair can only cause a great deal of discomfort. Not only can it affect the quality of your work but it can increase stress in the back, shoulders, arms and legs. And no one wants that So it is of utter importance to take into consideration these 5 points before buying an office chair.StyleWith the power of social media it takes one celebrity to wear a particular piece of clothing for it to sell out within minutes. For example, Kate Middleton started to appear in the public spotlight more frequently following her engagement to Prince William in 2010. Obviously. And she sparked a media frenzy when her fashion pieces started to sell out within minutes As you may have heard, this was known as the Kate effect and has added a further 1 bi llion pound in sales every year in the UK fashion industry.Celebrity styles should not just be limited to clothing, you can create your own celebrity inspired office looks Office spaces should not be dull with boring colors and plain furniture because this can reduce work ethic and motivation. Furniture at work have created a cool Infographic with some celebrity inspired office looks that can help you determine the look that best suits you.Comfortable material and paddingThe choice of material and padding is a matter of preference and fit. However, it is essential that the material shouldnt feel bulky and over padded. Whilst some people like a cushioned back others do not, but when picking the right material that suits you it is important that it does not get too hot when in sight of direct sunlight. Also, there should be enough cushions to support the professional when sitting in buchung for them to sit for long periods of time without their back feeling strained and sore.Conside r how much space you haveOffice space is an important factor to take into consideration when buying an office chair. There should be enough room to move around as an office chair should encourage you to move in order to keep blood and oxygen flowing as well as giving the support your body needs.BackrestA backrest should be included on an office chair as sitting for long periods of time without back support can cause a great deal of stress on the lower back.ArmrestAn office chair ought to have an armrest to support the elbows to prevent neck strain. They should be adjustable therefore you can sit comfortably with your shoulders relaxed. Armrests should enable your elbows to relax but your arms and wrists should not be as you are typing.This article was originally published on YourCoffeeBreak.co.uk.