Talk:Steam turbine

Please clarify about fuel/energy sources

This article only mentions "steam", but is not clear about where this comes from, its driving source. For a layman it's not obvious if, say, modern ships, use gas, coal (and if so, what types?), or whatever.

It doesn't matter. There's some variation according to the steam temperature and pressure, but no difference for the source. Andy Dingley (talk) 22:38, 6 April 2013 (UTC)

Repeated content

The two longest paragraphs are about problems with turbines. I think they should be merged--some content is repeated. DonSiano 13:54, 3 August 2005 (UTC).

Poor wording

I'm just a layman. The sentence below (from the "Impulse Turbines" section) does not make grammatical sense. Please, someone correct it so it says what is intended:

The steam leaving the moving blades is a large portion of the maximum velocity of the steam when leaving the nozzle.

Perhaps this what is meant:

The steam leaving the moving blades still retains a large portion of the velocity it had after leaving the nozzle.

--216.165.154.93 21:14, 2 November 2006 (UTC) [JM]

I put in your wording. -- Kjkolb 06:34, 23 June 2007 (UTC)

Jonal turbine

I came across the term "Jonal turbine" while working on the article. I do not think that this is the correct spelling, as I have never heard of it and "Jonal turbine" in quotes does not get a single hit except for Wikipedia and its mirrors. Many of the turbine names next to Jonal turbine in the article were misspelled. I was able to find the proper spelling for all of the others, but I did not find anything on any of the variations of "Jonal" that I could think of. If the proper spelling cannot be found, I suggest that it be removed from the article. -- Kjkolb 06:34, 23 June 2007 (UTC)

I have never heard of a turbine of this name and couldn't find anything. Removed from article.--Dj245 00:19, 19 October 2007 (UTC)

A few errors on this page

Although I don't have time to look up references for my information, I have been exposed to steam turbines in school and noticed a few errors on this page. The first being the listing of impulse and reaction turbines. The turbines listed are all water turbine stages. I can't remember all 4 types of steam stages, but I know they include parsons and delaval stages. I believe Parsons is purely reactive and delaval is a cross between the two.

The other error is in the section talking about a steam turbine for ships propulsion. If you look into the wiki article on ships they talk about propulsion and how a steam turbine is less efficient than a comparable diesel. The main reason steam is used on a commercial ship is if the ship by nature of it's cargo (such as a liquified natural gas ship) has a source of fuel available that it can't burn in a diesel engine it will use that to drive a steam turbine. The other use is in a nuclear ship where the only way to extract the power is to produce steam. Although a steam turbine takes up less space that a comparable diesel engine, the equipment required to run the turbine (boiler and steam piping) takes up considerably more space along with the added dangers of having high pressure superheated steam. —Preceding unsigned comment added by 72.90.173.42 (talk) 12:33, 21 January 2008 (UTC)

I agree with the turbine types, it looks like someone scoured the web and inserted any old thing they found. However, I think it may be possible to run a diesel on LNG tanker boil-off gas. Does natural gas autoignite at a reasonably obtainable temperature and pressure? I also agree when looking at the whole plant, steam is almost always larger than a comparable diesel. Very large diesels need their own auxiliaries and heat exchangers though which increases the size and complexity of the plant.--Dj245 (talk) 05:51, 24 January 2008 (UTC)

The wiki for ships meantions the technology being developed, and slowly implemented for operating an ICE via LNG boil off gasses, but it sounds like it is a relatively new technology. ICEs generally require some modifications to operate on a different fuel type than they are designed for, but it is possible. Diesel engines are inherently complex, but a slow speed diesel will have a similar shaft speed to the most efficient propeller speed for a large ship, whereas a steam turbine requires a pretty significant reduction gear setup.161.154.235.245 (talk) 16:26, 28 January 2008 (UTC)

Bold text

187.72.253.156 (talk) 04:41, 13 May 2014 (UTC) Someone with enough power to deal with images could add the indexes to U1 and U2 in the triangle diagram. It is implied in the drawings that the upper part have index 1 and the lower part index 2, so this is just a matter of improving the quality of the article, not really fixing an error. Thank you.

Electric drive

I don't think I'm the person to do it, but the section on speed reduction should mention electric drive. This was used in some US battleships between the two world wars. There were certain advantages: one turbine running flat out is more efficient than four running at quarter-power, but the opposite is true for electric motors driving marine propellers, and full power was available for going astern. Philip Trueman (talk) 20:06, 18 February 2008 (UTC)

Electric drive is not a method of gear reduction. It is an alternative method of power transmission and control. It is currently used in certain British naval ships, but has little to do with reduction gears.--Dj245 (talk) 01:39, 19 February 2008 (UTC)

I didn't say anything about reduction gears. Neither the article nor the section is about gears, nor should it be. The section is about speed reduction. The point is that the optimum speed for a steam turbine is mis-matched with the optimum speed for a marine propeller, and there is more than one way of overcoming the mismatch. Reduction gearing is one way; sometimes double reduction gearing is used. At the time the Royal Navy began applying reduction gearing the US Navy began applying electric drive (to battleships, at any rate). The two navies had different priorities, with the Royal Navy emphasising efficiency at full speed and the US Navy, with the vast distances of the Pacific in mind, emphasising efficiency at slower but more economical speeds. One figure I've seen quoted is that electric drive gave a fuel saving of about 20% at those speeds, for the reason I've explained above. Philip Trueman (talk) 15:09, 19 February 2008 (UTC)

Reversible, Reversing

The first paragraph seems to imply a relation between a reversible process, and the physical reversing of a marine turbine. The two or not related. Perhaps, the last line of this paragraph referring to a reversing marine steam turbine should be removed from the introduction for clarity. SFKatUMO (talk) 17:19, 2 March 2008 (UTC) —Preceding unsigned comment added by SFKatUMO (talk • contribs) 16:42, 2 March 2008 (UTC)

I agree and have removed the sentence. Also, the matter probably didn't deserve mention in the introduction. Thincat (talk) 15:59, 7 April 2008 (UTC)

Humm. I agree the unfortunate juxtaposition had to be fixed, but the sentence removed still made a valid point. It was usual, in the days before reversible-pitch propellers, for ships to be equipped with several turbines per shaft - say, one for full power, one for slow-speed cruising, and a reversing turbine. The reversing turbine wasn't reversible, it just turned the shaft the other way. For reciprocating engines there were ways of getting the engines to turn the other way, but a reversible steam turbine would be a nightmare to design, hence the need for a dedicated turbine. The history of reversing turbines goes right back to Parsons' Turbina. Electric drive also provided another solution to the problem. Perhaps room could be found to make this point elsewhere in the article? Philip Trueman (talk) 14:10, 8 April 2008 (UTC)

Yes, I don't find the article too clear on the "reversing" aspect and more detail (though maybe not in the introduction) would be welcome. I have just now moved the notion of "reversible" out of the introduction and into the section on efficiency. This might clear the ground generally, and for reintroducing "reversing" near the top, if anyone thought it beneficial. Thincat (talk) 08:17, 15 April 2008 (UTC)

about 86% ...

The article says about 86% of the world's electricity is generated using steam turbines. There's a [citation needed] tag, and there are some cites I could put in for this: [1] [2] These pages just seem to pull the figure out of thin air too, though. Are there any authoritative sources available that speak to the other 14% of electricity or mention some real research?--Martinship (talk) 09:10, 29 April 2008 (UTC)

You could also determine what percentage of sources are Coal, Nuclear, Oil-fired, Geothermal, and biomass (usually woodchips). If it isn't PV solar, wind, or gas turbine, its a steam turbine.--Dj245 (talk) 16:42, 30 April 2008 (UTC)

... and then you'd still have to apportion the power generated by gas-fired combined-cycle systems. Philip Trueman (talk) 18:44, 13 May 2008 (UTC)

Having a long history in the engineering of utility powerFredrosse (talk) 17:55, 5 December 2013 (UTC) cycles, I can vouch for the 80% vicinity for steam turbines. The USDOE publishes the energy mix in the USA, data from a couple of years ago provides the energy breakdown as follows: Hydro power=8%, Piston Engines burning Diesel fuel=2% Gas Fired Power=18% Renewables=2% Coal Fired Power=50% Nuclear Power=20% Within these regimes, Nuclear and Coal fired are all steam turbine Rankine cycles, totaling 70%. Gas Fired power is divided into three classes, Gas Fired Rankine Cycles, about 4% of the 18, all steam turbines, Gas Fired Combined Cycles, 12% of the 18, about 2/3 of a combined cycle output is from gas turbines, and the remaining 1/3 is steam turbines, thus 4% of the total power production, and simple cycle gas turbines, at less than 2% of the power mix. Renewables are almost all steam turbine cycles at 2%. That adds up to 50 + 20 + 4 + 4 + 2 = 80%. Note that wind and solar are growing, but still not very significant in the total power mix. The rapid expansion of natural gas mining in the USA will shift away from Rankine steam cycles, and generally promote gas fired combined cycles. The combined cycles produce about 1/3 of their power with steam turbines, so it is expected that the fraction of steam turbine power in the USA will be going down, but this is a slow process and probably will not go below the mid 70% share.

Unclear

I don't think this article is anywhere near clear enough about how the increasingly larger set of blades interact with one another. There is too much jargon and not enough dead simple explanation. This is why I came to this article and it really doesn't do the typical good job I've come to expect of a wikipedia article. I know that high speed steam blows on the blades and that turns a shaft but why and how do the blades interact? Johnor (talk) 20:38, 29 April 2008 (UTC)

I don't think they do, in the way you mean. There are two interleaved sets of 'discs' of blades: one fixed, and one rotating. As the steam expands its thermal energy is converted to kinetic energy which is directed onto the moving blades. The blades speed up, the steam slows down, and then the next stage of expansion occurs. Does that help? Philip Trueman (talk) 18:42, 13 May 2008 (UTC)

Remove Plagiarized

I have removed plagiarized sections from [3] and [4]. Additionally, the reference to [5] did not include citation for the referenced statement. Kilmer-san (talk) 16:55, 11 August 2009 (UTC)

Are you sure? I think they are pinching Wikipedia articles without acknowledgement. A lot of their stuff incorporates material from various WP pages. --Old Moonraker (talk) 18:14, 11 August 2009 (UTC)

Compared a few more of their pages with the equivalent pages here: it seems fairly clear that their material comes from here, and not the other way around. RV. --Old Moonraker (talk) 18:18, 11 August 2009 (UTC)

This could become increasingly problematic. A source I used for another article has since been expanded to include material I wrote in that WP article -- however, no-one has accused me of copyvio/plagiarism, yet...

And for another I was asked to add a snippet from a newspaper site as a reference, but the article was already referencing the Wikipedia article by name!!

EdJogg (talk) 23:35, 11 August 2009 (UTC)

Prior to reverting, I looked for evidence that the articles I mentioned were copied from WP, and the http://www.worldofcogeneration.com/member.php?u=1 site does list a source as: Sam Purl, Pangea Digital Media Ltd., which is not WP. So the perponderance of evidence seems to suppot copying to WP, and not the other way around. Sufficient inline citations would leiminate this issue. Kilmer-san (talk) 18:08, 12 August 2009 (UTC)

Looking further inot the page history, it appears this article is original (see this diff [6]). Sorry for the confusion. Kilmer-san (talk) 18:15, 12 August 2009 (UTC)

Having looked into this more closely, I would suggest that your first reference (www.worldofcogeneration.com) started life as a copy of the Wikipedia page at some point in its past. The 'give-away' is the text just after the "Speed Reduction" heading, towards the end of the document: The Turbinia - the first steam turbine-powered ship just happens to be the caption from the image at the end of the WP article! If you have the inclination to find out the version they used, we could justifiably raise a complaint and ask them to remove the page, since the GFDL requires users of the material to maintain a link to the source. (Personally, I wouldn't bother!)

The second ref (www.birrcastle.com) is not related to this article, although a previous editor could have used it as a source for the article without referencing it. Although such action could be considered plagiarism, the alternative would have to be Original Research: since Wikipedia articles should not be based on Primary sources, all Wikipedia content is, to a greater or lesser extent, plagiarised, so I wouldn't worry about this either!

Copy-vio is more serious, but in most cases the correct action is probably to highlight your concerns on the talk page (unless the whole article is a straight copy!) and allow other editors the chance to examine it and comment. The text can be re-worked very easily to avoid the problem without losing information. Where you may well run into problems is where a page has been created/edited by a website owner who has used text from his own website (I've seen this before). Ignoring 'Conflict of Interest' issues, it is not copy-vio for someone to write text on his website and then copy it to WP, or vice versa.

EdJogg (talk) 20:33, 12 August 2009 (UTC)

droop speed control

""On very large electrical grids--commonly referred to as "infinite" electrical grids--there is no single machine operating in Isochronous Speed Control Mode which is capable of controlling the grid frequency; all the prime movers are being operated in Droop Speed Control mode. But there are so many of them and the electrical grid is so large that no single unit can cause the grid frequency to increase or decrease by more than a few hundredths of a percent as it is loaded or unloaded."" ref - droop speed control

this contradicts the article statement:

""while some applications (such as the generation of alternating current electricity) require precise speed control.[9] "" Wdl1961 (talk) 03:43, 24 August 2009 (UTC)

Load balancing states of droop speed control: "if the frequency decreases, the power is increased", implying that the speed is to be maintained. A very hasty google offers: The ability to return to the original speed after a change in load is called isochronous speed control" (my italics). --Old Moonraker (talk) 06:13, 24 August 2009 (UTC)

google "droop speed control" pls and read more than one entirely. net power plants in the us have a five percent droop for stability .isochronous speed control is usually only for isolated single source powerplants . Wdl1961 (talk) 13:00, 24 August 2009 (UTC)

It's certainly true that steam turbines are mostly used for net (UK:grid) power plants, but surely this is where Load balancing is employed. "Droop speed control" is a redlink on Load balancing; perhaps what we need is a knowledgeable editor to create an article for this topic and thereby iron out any perceived inconsistencies between articles. --Old Moonraker (talk) 13:31, 24 August 2009 (UTC)

droop control means it is instantaneous with a governor which adjust the speed from no load to full load with a five percent speed drop. the governor can be reset on a new set point raising this curve and thereby changing the output of the plant. this has to be done slowly as not to disturb the stability of the net. Stability is the primary concern because if lost it usually means breakdown in large portions of the net. even with all of this more hvdc links are installed to increase stability .realize that droop control is automatically balancing the loads on the power plants. it certainly would be an interesting article but i am sick of "editors" placing a tag on it because they are to lazy or ignorant read the refs that are there . Wdl1961 (talk) 14:46, 24 August 2009 (UTC)

I can't work out what your pronoun antecedent is here, but as my last edit was to add a ref, I'm happy to assume that I'm not the target of this seeming personal attack.--Old Moonraker (talk) 14:56, 24 August 2009 (UTC)

sorry it is just a general observation.the biggest problem is to get the right keyords on a search . you are welcome to start an article on the subject and you can ask me anything with my email address . Wdl1961 (talk) 15:17, 24 August 2009 (UTC)

Thanks for the clarification: I appreciate it. --Old Moonraker (talk) 16:10, 24 August 2009 (UTC)

Calculating turbine efficiency

An anon editor recently added the equations in this section, without refs. Could someone confirm accuracy please?

EdJogg (talk) 15:27, 7 December 2010 (UTC)

I wouldn't include these myself; they are concerned more with the thermal efficiency of a complete boiler+turbine(+optional condenser) plant. The previous paragraph (isentropic efficiency) is the relevant one in this article 86.176.165.110 (talk) 01:10, 18 October 2011 (UTC)

Deleted 86.3.108.31 (talk) 05:05, 7 March 2012 (UTC)

"Practical thermal efficiency of a steam turbine varies with turbine size, load condition, gap losses and friction losses. They reach top values up to about 50% in a 1200 MW turbine; smaller ones have a lower efficiency." (in: Principle of operation and design) I doubt that. Steam turbine efficiency is next to 100%, when the steam input is compared to the mechanical power output plus the (partly) expanded steam output which may be used in the next stage or in a heating condensor. Modern coal fired plant achieve 46% and the losses are not in the steam turbine, but in the condensor and the emission of low temperature waste heat which is needed for entropy disposal. So it's an issue of the whole Rankine cycle, but the turbine is performing almost insentropicly (at least with the larger designs) and not at about 50%. --Gunnar (talk) 04:43, 26 July 2018 (UTC)

Steam Turbine Hybrid Alternative

Of course, no innovation is welcome unless it is carefully studied and understood. While the Conventional Turbine is perfectly balanced, and continuous in steam flow and torque, the Wankel Rotary Engine fail to be balanced (due to eccentric shaft) and fail to be continuous in flow and torque, because it has 30 degrees dead times (3 times per rotation). New concept like the Quasiturbine Air / Steam Engine has a perfectly balanced rotor and joined torque pulses for quasi-continuous steam flow and torque. Consequently, the Quasiturbine is a sort of hybrid between Conventional Turbine and Rotary Wankel, being a low-rpm-high-torque uniflow positive displacement rotary design, particularly suitable for direct drive steam power system.

As a first contact with this new QT technology, one can have a look at the University of Connecticut « Brash Quasiturbine QT.6LSC Air / Steam Car » Video : All day long Run (0,3 min.) and Variable speed Run (9 min.) and more on Brash power system

For theses reasons, readers interested by Conventional Turbine may have interested to « SEE ALSO » Tesla and Quasiturbine for a complete Steam Turbine overview. —Preceding unsigned comment added by 74.56.253.176 (talk) 16:11, 25 March 2011 (UTC)

No complain, but a few words to think about: There is always a risk that innovation makes obsolete some of the conventional technologies that we dear so much. This is very frustrating. It is also frustrating when innovation forces the redefining of conventional approaches and restrictive historical terminology and interpretation, in order for the innovation to fit somewhere. In reaction to this frustration, encyclopedians must resist the temptation to spontaneously favors historical material, while excluding vision and perspective of present and future technologies and lifestyle. Readers have expectations: To be interesting and modern, an encyclopedia has to be a little more than a 300 years historical museum brochure. List of motive for exclusion can be endless, but each page gains to have some roots also in the present and the future. There is of course no Wiki rule supporting exclusion of present and future innovation from any page, and over time, the need of constant updates insures « Wiki Enrichment ». Waiting for updates rewards the readers... With or without more inclusion of current innovation, the page is definitively interesting and well done. Innovation needs friends and supporters, not enemies, nor morale lesson from either side. Friends of innovation need time to grow, even if time does not exist anymore in modern science... Wiki is impressive. Keep on your good work. Cordialement, Gilles —Preceding unsigned comment added by 74.56.253.176 (talk) 22:41, 27 March 2011 (UTC)

To avoid duplication, please see Talk:Steam engine#Rotary Steam Alternative versus BRASH where discussions on the same topic may be found... -- EdJogg (talk) 12:17, 28 March 2011 (UTC)

The Quasiturbine, not being a turbine, should stay on its own page and be referred to from rotary engines and internal combustion engines, for which it has some affinity. Just because it is misnamed is no reason for it to be miscategorized. Dlw20070716 (talk) 04:26, 9 June 2011 (UTC)

Reactive turbine blade form

In the text reactive turbines are said to have blades forming convergent nozzles (no attribution). The adjacent figure does not make this detail clear. In fact, they look more like they are convergent/divergent passages, if they converge at all--they are rather clearly airfoil-shaped. (I would also not use the word nozzle for a passage that does not have a hollow shaped with a circular or nearly circular section, which the hollow between two blades most certainly does not.) I think an attribution is also in order at this point. — Preceding unsigned comment added by Dlw20070716 (talk • contribs) 04:17, 9 June 2011 (UTC)

T-s diagram VS Explaining Isentropic Efficiency

It's unfortunate that this diagram is opposite the paragraph on isentropic efficiency: (i) The diagram and the text do not share the same station identification scheme. (ii) The diagram does not show isentropic (ideal) expansions, a key part of what the text is talking about. 86.176.165.110 (talk) 11:43, 18 October 2011 (UTC)

I agree! It would be great to see a new diagram showing the graphical method for calculating Isentropic Efficiency - lines on a Mollier (h-s) Chart.--Graham Proud (talk) 12:40, 18 March 2013 (UTC)

units

the article mixes the sequence of units (hp v Kw) throughout, I've standardised on the si unit first. Markb (talk) 12:22, 10 February 2012 (UTC)

19th century chinese book on steam turbines

http://books.google.com/books?id=904qAAAAYAAJ&printsec=frontcover&source=gbs_ge_summary_r&cad=0#v=onepage&q&f=false

Title 汽機必以: 十二卷, 卷首一卷, 附錄一卷, Volumes 28-37 Volumes 28-29 of 西學富强叢書: 工藝學 汽機必以: 十二卷, 卷首一卷, 附錄一卷, 汽機必以: 十二卷, 卷首一卷, 附錄一卷 Author 張蔭桓 Publisher 鴻文書局, 1896 Original from Harvard University Digitized Jul 28, 2008

Rajmaan (talk) 17:57, 1 January 2013 (UTC)

Error

< The steam turbine is a form of heat engine >

Absolutely not true - it's merely an expander (that together with a lot of other stuff makes up a heat engine). — Preceding unsigned comment added by 86.176.160.42 (talk) 11:59, 3 August 2013 (UTC)

Error in velocity triangle

Velocity triangle

The V_w1 vector is the horizontal component of the V₁ vector. But the diagram in section 3.1.1 (about impulse turbines) shows it as the horizontal component of the V_r1 vector. The diagram should be changed. --EngineeringGuy (talk) 20:26, 29 January 2015 (UTC)

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