Keynote presenters at the PowerGen Europe conference and exhibition in Amsterdam last month touched on several pressing issues that, they maintain, must be addressed if Europe is to have secure, affordable and sustainable energy in the coming years.
Siemens has delivered a steam turbine in the capacity range up to 10 MW for the first time, which operates almost entirely without lubricants. The bearing systems consist of completely oil-free, air-cooled, electromagnetic bearings.
These are excerpts from a paper titled, ‘Revamp/re-rate design considerations’ presented at the 43rd Turbomachinery & 30th Pump Users Symposia (Pump & Turbo 2014) held from September 23 to 25, 2014 at Houston, TX.
I am an extremely avid reader and usually devour two or three books a week. My library is packed with books ranging from the short and easy-to-read 200-page fiction crime and mystery novels to profound literary 1,200-page anthologies and historical compendiums.
But I must also shamefully admit that I frequently end up picking up all the short books and seldom have the time or mental energy to crack open any text that is longer than 500 pages. These books are just too long, have too much information and are too much of a time commitment.
The following is a continuation of our previous discussion on rubs. We will begin with a brief review of some basic concepts and then give an example of a rub with supporting data plots. In upcoming blog articles which will continue this discussion, additional rub examples will be depicted.
Damping helps remove energy from a system through resistance to motion. For rotating equipment, damping is necessary to prevent vibrations from damaging the rotor, bearing or other components. Unlike rolling element bearings, fluid film bearings have a significant amount of damping. But even the damping provided by fluid film bearings is not sufficient for all rotating machinery. The stiffness of the fluid film bearing can counter the damping capability. Therefore, an additional means of increasing “effective” damping to the system is needed.
Usually, turbomachines show satisfactory vibration levels during test runs at the manufacturer’s shop. However, vibration levels after the commissioning could be higher than desirable levels. Too often, after several months of operation, vibration could show some increasing trends.
Nozzle repair is something that combustion Turbine Operators Task Force (CTOTF) group members are very familiar with. At this year’s spring conference, CTOTF invited Aaron Frost, Technical Director at Allied Power Group, to go into the details of 7FA Stage 1 nozzle repair. He warned the audience that the new 7FA.04 has lots of cooling holes and is made of GTD-111 material that is essentially unweldable.
The IPP3, said to be the world’s largest internal combustion engine (ICE) power plant, was recently inaugurated at the plant site near Amman, Jordan. The plant is powered by 38 Wärtsilä 50DF multi-fuel engines with a combined capacity of 573 MW.
In the second part of this series, the author highlighted the uses of ASCS and discussed multi-point and mono-point systems. This article focuses on the vibration control unit, speed controller and surge controller unit.
Vibration control unit
Radial bearing vibrations:
In the first part of this series, the author explained the significance of the anti-surge protection system in a compressor. In this article, he compares multi-point systems with mono-point systems and highlights the uses of ASCS.
The parameters affecting the anti-surge control system are discharge pressure, suction pressure, flow rate and suction temperature.
Surge control systems
Vishal Jariwala, Daryll Turner and James Hardin of Elliott Group presented a paper titled, ‘Computational Investigation of Coupling Guard Heating and Mitigation’ at the 43rd Turbomachinery & 30th Pump Users Symposia (Pump & Turbo 2014) that took place from September 23-25, 2014 at Houston, TX. Below are some of the excerpts:
Centrifugal pumps are widely used in industrial applications. Pumps driven by medium-to-low-power motors (70kW), for example, represent almost all of the installed machines deployed in oil & gas process plants.
In our last column, we talked about nitrous oxide as a potent greenhouse gas and how it was often mistakenly associated with power plant emissions. In this column, we will continue with the topic of greenhouse gases (GHGs) but focus on natural gas leakage and unburned hydrocarbons from the U.S. energy infrastructure.