Recent content by deckart

I found an abstract of a thesis written about replacing wind turbine gearboxes with hydraulic transmissions here: https://scholarworks.iupui.edu/handle/1805/3800 I like where she is going but again, it looks like she is considering the use of conventional pumps as opposed to a more efficient...

All I have to go on is what I can find through searches. This is where I found the original .8-.9 gearbox efficiency: https://wind.globecore.com/wind-turbine-gearbox-efficiency.html This article puts them in the range of 90-95%: http://people.bu.edu/dew11/turbineperformance.html. cjl, you...

Regenerative meaning that the energy is not wasted and expressed as heat. It is put back into the system by increasing the torque of the pumping mechanism, as I have described, to reduce velocity. There are additional methods that can be utilized but that is regenerative braking without any loss...

Accumulators are really just capacitors. As shown with that calc sheet, they aren't suitable for that scale of storage. Their strength is in that they can absorb and release energy quickly and make hydraulic power available for auxiliary functions. I think you are right, being that there is a...

Good stuff, thank you. Looking at the graphic below for a 5MW wind-turbine, there is a great deal of cost getting from the turbine to the generator. And, according to this article, the transformer should not be something off-the-shelf but constructed to deal with the variable velocities of the...

A hydraulic accumulator used for energy storage is simply a hydraulic cylinder without a cylinder rod. A floating piston separates the gas and hydraulic fluid. Here is a chart showing standard sizes from a supplier that I use, https://www.accumulators.com: As far as cost for a small unit...

Got it! I was just looking at Watts. This wouldn't work in that capacity at all!

I estimate that the accumulator bank illustration with the man standing in it is approximately 1000 gallons. I contacted a friend who has had to make these calculations before in his consulting work. This is what he sent me: One complete charge would power the average US home for more...

Yep, these are good ideas and would work well in areas that have large volumes of water available and the geography to support storage. With hydraulic accumulators, the energy density can be very much higher. 100 psi of head pressure would require 50 times the volume of fluid that is can...

Here is an example of what an accumulator stand might look like for a large wind-turbine station: Thermal losses are determined by the rate of charge and discharge. A system sized for slow charge and discharge will mitigate the impact of thermal losses. Inefficiency will depend on how the...

This forum makes for a good chalkboard! I've been doing some more research into the challenges of current large-scale wind turbine arrays. One of the problems, of course, is energy storage. There are often demands when the wind isn't blowing. There are meteorological projections considered in...

Sure, high-speed pumps can be scaled to operate at low speeds. But they aren't. There is no market for them and that is why they don't exist. Pumps require a prime mover, something to drive them. The common items that drive pumps operate at high-speeds, i.e. gas engines, electric motors. There...

The shifting of each cylinder is accounted for in the model. With the shaft driving the cylinders at 2000 psi the combined forces average to approximately 4900 lb-in of torque at the shaft. +/- 8% throughout the entire rotation. This was a great exercise! With multiple radial cylinder sections...

I expect there will be an oscillation but I'm interested in the maximum torque. I will have to plot various positions to determine what that is

I've come to the conclusion that determining the torque about this point (the small red xy arrows) is simply a summation of the forces of these torque arms. Does anyone concur? I believe I was making it more difficult than it is.