Talk:Fossil fuel power plant

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A fact from Fossil fuel power plant (or a previous version of it) was included in the Did you know? section of the Energy Portal.

If you want to help, we could use some appropriate photos. There is plenty of opportunity for expansion. There could be a section on operator controls, and more detail on water treatment, and pollution control, for example. --Blainster 10:00, 2 Mar 2005 (UTC)

This is written from memory (personal experience) so checks on things like flow rates, pressures, and temperatures are particularly appreciated. --Blainster 00:00, 9 Mar 2005 (UTC)

1 Water purity
2 Comparative Stack Gas volumes
3 Steam-electric power plants
4 Further Response to Blainster
5 Pollution
6 cold/hot startup
7 Global view tag - re costs
8 Trains per day
9 Coal power and radiation
10 Other Pollution Issues
11 Re: 'waste heat' edit...
12 Do we really need 4 articles on the same subject?
13 Is this correct?

[edit] Water purity

It seems the industry standard unit is microsiemens per centimeter. A Google search turned up this reference [[1]] whose Table 1 says chemically pure water has a conductivity of 0.038 microsiemens per cm, and demineralized water up to 1.0 microsiemens per cm - which looks like the magnitude for boiler feedwater. Per metre would be 100 times smaller, which isn't possible. --Wtshymanski 19:22, 5 August 2005 (UTC)

indeed, a conductivity of 0.038 uS/cm is ultrapure water, also known as MilliQ water. This quality is quite hard to achieve, requiring expensive columns etc. Still I don't understand the question your asking... Sikkema 12:52, 23 January 2007 (UTC)

[edit] Comparative Stack Gas volumes

This section compares flue gas volumes for different fuels, but does not state why this is of interest. An encylopedia needs to give context for the information presented, so that it will be useful to non-specialists. Much of the data in the table is not relevant to its accompanying statement. The image itself is problematic, consisting of a bright color graphic of a table of data. The color is obtrusive. The format is wasteful of page space. As an image, the table is uneditable. I suggest editor Mbeychok replace it with a table that is editable. As it stands, the graphic is not any more useful or relevant than putting steam tables or power generation curves into the article. --Blainster 21:24, 20 January 2006 (UTC)

So what is it, a rough measure of how 'smoky' each fuel is? Tom Harrison ^Talk

Actually, no, "smokiness" generally refers to opacity, or how difficult it is to see through. Opacity is measured in percent, and is a rough measure of the concentration and size of particulate matter in the flue gas. I am waiting for editor Mbeychok to explain what he has in mind. --Blainster 23:04, 20 January 2006 (UTC)

(Response to Blainster from MBeychok) The concerns of the public and of our regulatory agencies with what comes out of the flue gas stacks from power plants (or any other large combustion furnaces) has increased ten-fold or more during the twenty years since you worked in a power plant. A great many people have the mistaken idea that coal burning creates a great deal more total flue gas than a "cleaner" fuel like natural gas. As shown in my table, coal burning does create more flue gas, but only marginally so. I did not want to dwell on that in my contribution lest I sound biased in favor of coal burning ... which I am not. I wanted the table to show the facts and to speak for itself.

I suggest the information in the table needs better verbal explanation. The section does not state why the table belongs in a general article describing a power plant. Remember the encyclopedia is targeted at the educated layperson, so you need to provide context. I don't see how explaining the importance of flue gas volume could be considered a bias. --Blainster 22:56, 26 January 2006 (UTC)

Deleting the table and only leaving the comparative scf/10⁶ of flue gas for each of the fuels pretty well "guts" my contribution because:

The credibility of my calculated results depends upon readers being able to see the compositions that I used for each fuel and to ascertain that they are typical ... not selected to bias the results. With those compositions, readers could actually perform their own calculations to check my results if they wanted to do so. Without the compositions, they could could not make independent checks.
The credibility of my results also depends upon the readers being able to see what percentage of excess combustion air I used ... again to ascertain that I did indeed use typical values. And those excess combustion air values are also needed to permit independent checks of my results.
- I was attempting to condense the information to summarize the point I think you were trying to make. But of course your followup edits and thoughts are appreciated. This kind of detail is more likely to confuse than enlighten the general reader. If you wish to provide a tutorial, Wikibooks would be a more appropriate forum. There would also be more latitude for calculations in a subarticle on air pollution measurement and control. --Blainster 22:56, 26 January 2006 (UTC)

Quite a bit of my table concerns how to convert the results into units used by some 99% of the world (the USA is the only nation still using scf and Btu's rather than metric units). Believe it or not, the vast majority of people on the planet don't know how many inches there are in a foot.
- Unit conversions are normally covered by links to articles on the units which already exist in Wikipedia. There are already some examples of this in the article. --Blainster 22:56, 26 January 2006 (UTC)

All steam tables contain the same data because water has a fixed set of physical and thermodynamic properties. There are literally thousands of different composition natural gases, fuel oils and coals, all with different heating values, carbon-to-hydrogen ratios, and different physical properties. That is another reason why the readers should have my table to look at rather than just the final results.
- There could be loads of detail on steam properties which drive pressure vessel design, or coal properties which drive furnace design, but these things really belong in subsidiary articles. --Blainster 22:56, 26 January 2006 (UTC)

As for my table being a graphic image that is not editable, I would point out that photographs are also not editable. I don't see where that is relevant. I created that image some time ago so that I could use it on a number of Internet forums without having to cope with the plethora of markup languages in use (HTML, BB code, PHP code, Wiki markup, etc).

Placing textual information into an image is not allowed by the community, because it prevents collaboration, which is the heart of the Wiki process. I can sympathise with not wishing to learn table code in Wiki, but one way to handle that is to place the information on the page and ask for help in getting it formatted. --Blainster 22:56, 26 January 2006 (UTC)

As for your finding the color "obtrusive", one person's "obtrusive" may be another person's "favorite color". Does the Wikipedia have a "color" standard somewhere that I haven't yet found? Or do the Wiki editors have some "color police" looking for inappropriate colors?

This is of course my opinion only. Color is negotiable, I would suggest pale colors are more readable on text pages. --Blainster 22:56, 26 January 2006 (UTC)

Blainster, I also responded to you in your User discussion page ... I hope that you've seen it.

Mbeychok January 20, 2006

Yes, thanks for your input. A brief note on my user page will suffice (that triggers the message flag) with no need to duplicate the detail here. See my responses above, and once again, I appreciate your help in improving the article. --Blainster 22:56, 26 January 2006 (UTC)

[edit] Steam-electric power plants

I removed steam-electric power plant as an alternate name because it is incorrect. The article I created gives a better definition. Also, not all fossil fuel power plants are steam-electric. Gas turbines and reciprocating engines can be fossil fueled and they are not steam-electric (reciprocating engine power plants usually aren't very big, they range from 1 kw to about 20 MW). -- User:Kjkolb 22 January 2006

[edit] Further Response to Blainster

In your original message to me on my user talk page, you said:

"We do not own the material we contribute, so be prepared to have your entries edited mercilessly— the thought "but it's my article" should never cross your mind."

It seems evident to me that most of your points against the table that I contributed to this article (which you say that you wrote) are because you do indeed consider the article to be your own. Rather than carry this discussion any further, I have completely removed the table that I contributed. I have better things to with my time. mbeychok 17:28, 27 January 2006 (UTC)

On the contrary, I welcomed the changes you made to my text. It is you who seem to consider your contributions inviolate. It is regrettable that you do not wish to carry on a discussion, which is the heart of the process of building a collaborative encyclopedia. But I harbor no ill will—if you feel inspired to rejoin the endeavor at any time, you are welcome to do so. --Blainster 17:44, 27 January 2006 (UTC)

[edit] Pollution

It seems that a section on pollution should be included but I'm reluctant to do this myself since this isn't really my area. In particular I believe the otherwise generally unknown but potentially very relevant and worrisome aspect of radioactive waste should be included (article currently contains an external link but otherwise no mention of the problem). 212.48.126.140 10:30, 22 May 2006 (UTC)

It is unclear what kind of radioactive waste you are referring to. The small number of radiation sources used in power plant instrumentation are compact, sealed, licensed, and regularly inspected. Fossil fuel plants do not produce any waste of the sort produced by nuclear power plants. All coal has a small degree of natural radioactivity, and this is somewhat concentrated in coal ash, but is a much smaller hazard than the naturally occuring radon gas that collects in residential housing, for example. --Blainster 17:16, 22 May 2006 (UTC)

I was refering to the trace elements that would be insignificant if there wouldn't be such a large amount of coal (or whatever) being burnt. The external link http://www.ornl.gov/info/ornlreview/rev26-34/text/colmain.html claims that a typical 1GW power station releases 5.2 tons of uranium and 12.8 tons of thorium per year. Even if one considers that maybe only 1% of it is not caught in the coal ash and is released into the biosphere, it still seems somewhat alarming especially considering the public outcry that would result if a nuclear powered facility would release radioactive waste of that magnitude. There are possibly other factors involved that make the situation more harmless than it seems but if there are, it would be good to be able to read about it here. However, I did find this mentioned on the coal page so this is all perhaps a mute point.212.48.126.140 13:15, 23 May 2006 (UTC)

This is true: in a nuclear facility in the UK, called ISIS, the majority of radiation measured outside comes from the precipitation of the radioactive elements from a nearby coal plant. The radiation on the inside is actually lower!!

—The preceding unsigned comment was added by Sikkema (talk • contribs) 12:57, 23 January 2007 (UTC).

I am more concerned about the health effects of mercury release from burning coal than radioactive elements. The EPA was set to implement mercury reduction requirements until the Bush administration pushed it back by ten years. (I think the word you want in the last sentence is moot, meaning debatable, not mute.) --Blainster 18:05, 23 May 2006 (UTC)

What you say about mercury is certainly relevant as well, not to mention whatever other heavy metals there may be, so perhaps a section listing all typical harmful pollutants would be beneficial. I still believe that the release of uranium and thorium is an underrated problem, for example, you wrote previously that radon gas is a concern (being a cause of lung cancer) and it would be interesting to know how much artificially released airborne uranium and thorium contributes to the production of radon (both elements can decay to radon). A hypothesis also exists that airborne uranium can be converted to plutonium, which is well known for its toxicity. (Yes, "moot" is what I meant. :-) Everything in Wikipedia is always so correct, unlike in other forums, one needs to be careful...)212.48.126.140 12:50, 29 May 2006 (UTC)

This article does need a pollution section though. raptor 11:22, 1 November 2006 (UTC)

I agree with raptor and 212.48.126.140, coal is infamous for its health dangers. The section should include radioactive fly ash, soot, nitrogen, carbon emissions, and everything else you can think of, why withhold information if you have it? I'd write it myself, but I don't know enough about it, nor do I have good sources at the moment. Also, to be frank, I don't think anyone cares about any one person's idea of which pollutant is most important; just put all of the pollutants in the section and everyone will be happy. 204.126.2.5 12 December 2006

I have added a very basic section on environmental impacts. Every power generation source on wikipedia has this section; if you feel the need to expand the article to include positive benefits of fossil fuel power, feel free to add those as well. If you take issue with any point of fact, please ask for clarification or citation. But a full discussion of the environmental impacts must be present to clear this glaring ommission of facts and to bring this article up to par with the other energy generation technologies. Sven42 03:28, 21 December 2006 (UTC)

Sven42, I wholeheartedly agree that power plants have environmental impacts ... just as do our autos and almost every other human activity. But your original contribution made it sound as if they were solely "responsible". Even now, your revised contribution includes "air pollution" (which is valid) but goes on to include scare words like "release of uranium and thorium to the atmosphere". Are they not included in "air pollution"? Why do you feel it necessary to use those scare words and why not point out that the amounts are quite small? It is that sort of overstatement that I consider to be a biased POV (point of view). I am an environmentalist myself but there is a difference between stating facts as against expressing what struck me as overblown bias. Regards and Happy Holidays! - mbeychok 05:12, 21 December 2006 (UTC)

I found a reference regarding Uranium and Thorium emsissions, but I'll let it be put in by someone more familiar with Wikipedia's style of writing. Here is the reference, I don't know how helpful it is, but it's at least a start. <http://www.physics.ohio-state.edu/~aubrecht/coalvsnucMarcon.pdf#page=8> —The preceding unsigned comment was added by 66.140.86.116 (talk) 22:07, 29 December 2006 (UTC).

I have read the entire website article that you referenced above. To me, it reads like 20 pages of a vitriolic rant against coal mining and against coal burning. It does not read like a credible scientific paper published in a peer-reviewed journal (or any other reputable journal) would read. For example, here is one quote "Given that so much crud is coming from coalstacks ...". I could find no mention of where this article has been published in any journal or book. As another example, it uses red fonts and very greatly oversized fonts when it wants to hammer home one of the author's points. I invite others to read that article and see if it strikes them as a balanced, credible scientific reference.

I also read the article at [2] which was referenced much earlier in this discussion by 212.48.126.140 ... and it is a much better and more believable article covering the same subject without any ranting. I will therefore include the following statement (paraphrased from the Wikipedia Coal article) in this article:

Coal contains low levels of uranium, thorium, and other naturally-occurring radioactive isotopes whose release into the environment may lead to radioactive contamination. While these substances are present as trace impurities, enough coal is burned that significant amounts of these substances are released, paradoxically resulting in more radioactive waste than nuclear power plants. I will reference that statement as being sourced to the above article provided by 212.48.126.140. I will also include the statement from that reference that a 1000 MW coal-burning power plant could release as much as 5.2 tons/year of uranium and 12.8 tons/year of thorium. - mbeychok 00:30, 30 December 2006 (UTC)

[edit] cold/hot startup

anyone can advise the difference between the 2?

First, let me say that you really should sign your user name to queries or comments. If you don't have a user name yet, you should sign in and get one. :)

That said, I did quite a bit of searching using Google and it appears that:

For thermal power plants, a cold startup is a startup that takes place after the power plant has been shut down for at least 48 to 72 hours (the exact number of hours varies from one reference source to another). A hot startup is a startup that takes place after the power plant has been down less than 2 to 48 hours (again the exact number of hours varies from one source to another). In other words, the difference between a cold startup and a hot startup depends on the number of hours that the plant has been shutdown and the exact number varies from one definer to another definer. The importance of the distinction between the two seems to be related to how long a plant may be permitted to exceed the regulatory limits on the air pollutant emissions of nitrogen oxides for example. In some cases, the nitrogen oxides regulatory limits may be different during hot and cold startups than during normal operation.
For nuclear power plants, the definitions are different. A hot startup is one that takes place while the nuclear reactivity is still decreasing (i.e., the plant has not yet been fully shut down). A cold startup is one where the nuclear reactivity is no longer decreasing because the plant has been fully shut down.

- mbeychok 20:28, 5 July 2006 (UTC)

It also affects how the operator starts up his plant. For example, the boiler will probably have been drained down (to prevent corrosion) prior to a cold start. The operator may need to pre-fire the boiler with gas to warm it, and the turbines be taken off barring (in which they are made to slowly rotate to prevent the hot shaft sagging). The principal effect is however determining how quickly the operator can start up the plant and ramp up its output. BillC 21:48, 5 July 2006 (UTC)

[edit] Global view tag - re costs

I presume the figures given are for the United States as I doubt that they are the same everywhere. If this is the case, the article should say so. Olborne 21:36, 10 September 2006 (UTC)

Olbourne, do you really think that one sentence about USdollar costs warrants labeling the entire article as lacking a global view? Seems like a pretty drastic personal judgement on your part. Do you have any good references giving significantly different costs in various countries? If so, why not include them in the article? - mbeychok 00:12, 11 September 2006 (UTC)

Olbourne, from what I could find in the History page of this article, it was created on March 2, 2005 by User:Blainster. I suggest that you contact him at User Talk:Blainster about the cost figures. - mbeychok 00:22, 11 September 2006 (UTC)

Olbourne, since you have not responded to my above comments, I am removing the global view tag. - mbeychok 23:17, 13 September 2006 (UTC)

[edit] Trains per day

3–5 trains per day doesn't sound right unless the trains at issue are shorter than unit trains, or are stockpiling fuel. A 2000 MW (sub-bituminous) plant at full load burns about 1000 ton/hour. But this would probably amount to no more than 16,000 tons in a day due to off-peak load reduction. The largest plants of around 3000 MW would then use 24,000 tons, which is still only 2.4 unit trains worth. --Blainster 07:46, 30 November 2006 (UTC)

[edit] Coal power and radiation

I think that the part about coal's supposed radiation exposure should be removed because of the many problems with the referenced article's reasoning. The article was written to promote nuclear power. The author works in nuclear energy and has no experience in dealing with coal or coal power plants. The first problem is that there is an extremely low amount of uranium in coal, about as much as is in the average piece of the Earth's crust. Second, very little of the uranium is released into the air, most of it remains in the ash, yet the article assumes all of it is released. However, even the uranium concentration in fly ash is not very great. It is about the same as the amount found in black shale. Third, whether it is in the ash or released into the air, 99.3% of the uranium is stable U-238, which emits no radiation. Fourth, the little uranium that is released quickly falls to the Earth, giving it little time to be breathed in (U-235 is an alpha particle emitter and can only cause harm if it is breathed in or eaten). Also, there are few people in area immediately surrounding coal power plants around to breath it in. Still, the amount of radiation for any people that are around, like workers at the plant, is minimal.

Besides this, the article makes stunning leaps of illogic and it is embarrassing for it to be used as a Wikipedia reference. One example is when the article claims that coal power is wasteful because of the amount of uranium that it wastes, which could be used for nuclear power generation. However, as I stated before, the amount of uranium in coal is extremely low. This makes the extraction of the uranium incredibly uneconomic. The article uses a number of 1.3 ppm (0.00013%) for the concentration of uranium in coal. The U.S. Energy Information Administration website says that the range of economic uranium ore is 0.05 to 0.20%. Therefore, coal has a uranium concentration about 385 times too low to be considered economic. Even if uranium ores of very low concentrations become economic in the future, it is certain that coal will never be an economical source of uranium. Even the ash, which has a greater concentration of uranium than the coal, is nowhere near economic. There are many other major errors. Several of the most serious occur in the area where the author claims that coal plants threaten nuclear proliferation (when I read through this part I thought that he might be joking because the reasoning is so ridiculous, but apparently he is serious). For all of these reasons, I believe that the content should be removed. -- Kjkolb 21:37, 31 December 2006 (UTC)

I would have no objection to your removing the section I added. I was simply trying to appease the above editors (User:212.48.126.140, User:66.140.86.116 and User:204.126.2.5) who dug up the article and a similar one also. I guess I just went too far in my appeasement. Happy New Year! - mbeychok 06:47, 1 January 2007 (UTC)

Don't worry about it. I'm only disappointed in Oak Ridge National Laboratory (ORNL). You expect information from a U.S. Department of Energy National Laboratory (ORNL in this case) website to be accurate, or at least I do. In almost all cases, I have found their information to be good and in many cases excellent. This article is the only major blunder I have come across. They really dropped the ball when they let this article get published. The United States Geological Survey has more accurate information on the subject.

Nuclear power has many advantages (few emissions, relatively abundant, massive fuel deliveries are unnecessary (they can be a problem for coal plants, especially those far from coal mines)) and many disadvantages (high capital cost, need long term radioactive waste storage, current designs are unsuited for anything but base load operation). However, people have been using the ORNL article to make false claims about coal power while promoting nuclear power (it has been used on other websites and on at least one other Wikipedia article). Making such claims does not do anyone or any cause any good. It makes nuclear power look bad for lying and fear mongering and it makes coal, which provides half the electric power for the U.S., look bad by those who take it at face value (coal has many actual problems of its own, of course). Unfortunately, bashing the other energy sources and making exaggerated claims about your own seems to be common practice in the energy industry and in energy research. It is not limited to coal, nuclear and oil, either. Some of those involved in renewable energy are equally guilty making false claims about themselves and others.

Anyway, I'll remove the content now. Anyone who objects later, please let me know. -- Kjkolb 12:46, 5 January 2007 (UTC)

[edit] Other Pollution Issues

Looking at the image ‘PowerStation3.svg’, it looks as though the cold water used in the condenser (8) which is then cooled inside the cooling tower (1) forms a closed system. Actually power stations tend to be sited by rivers, and in practice I think that it is river water which is used to condense the steam. Once it comes back out the condenser and is cooled by the cooling tower, I think it is then sent back into the river. I say this because I have heard about the damage to the environment that power stations can cause by raising river temperatures. As good as the cooling towers may be, they do not get the water back down to the original temperature of the river water. Which I suppose is the reason why fresh river water is then used again, because it is colder and will be better at condensing the steam. As you may be able to tell, I am no authority on these things, but I did want to make the comment.

I do not really understand why the steam must be condensed at all. It seems like a remarkable waste of energy. At the very least the hot steam could be made to do more work as it condenses – like in early steam engines, the vacuum type. Or a stirling engine could be used. In some places I know the hot water is used for heating. Why though, is the steam not simply fed back into the furnace? From the image ‘PowerStation3.svg’ I can see that after the high pressure turbine (11), the steam is reheated in the reheater (21). Why can we not reheat the steam coming out of the low pressure turbine? Over the years I would like to think that engineers have got quite good at perfecting some of these things. From this article though, I can not find the reason for what appears to simply be spectacular energy wastage (which in turn of course means needless pollution). Could someone please educate me? --JB001 13:16, 4 January 2007 (UTC)

Answering my own question, I suppose the vacuum created by condensing the steam helps drive the turbines faster. Does this sound right?--JB001 14:28, 4 January 2007 (UTC)

JB001, as stated in the article:Typically the cooling water causes the steam to condense at a temperature of about 90–100 °F (32–38 °C) and that creates an absolute pressure in the condenser of about 1.5–2.0 in Hg (5–7 kPa), a vacuum of about 28 in Hg (95 kPa) relative to atmospheric pressure. The steam is condensed at a temperature which results in a very low pressure (94% below atmospheric pressure!). That is done so as to utilize almost all of the usable energy in the steam and and thereby increase the efficiency of the turbines. So your self-answer was almost right.

Simply reheating the very low pressure steam exhausted from the turbines would not raise its pressure and thus it could not be re-used as high-pressure steam. However, the condensed steam is reused as feedwater to the steam generating boilers.

As one other point, not all power plants are located next to a river, lake or ocean. Regards, - mbeychok 17:07, 4 January 2007 (UTC)

Mmm. Thanks. I’m not great at thermodynamics. I’m glad there are engineers out there obviously more competent than I! I knew that absolute profligate waste would have been exorcised from the system by now. I was wondering just how efficient the process actually was, and how it could be improved. In this article there are sections on ‘Supercritical Steam Plants’, and ‘Gas Turbine Combined-Cycle Plants’ which partly address this. There is also an article on Combined Heat and Power elsewhere, that claims that by utilising the heat for productive purposes (heating things you want to heat), rather than just losing it to the environment as normally happens using cooling towers – you can improve efficiency from 35% to 70%. This would also eliminate the heat pollution of rivers some power stations create as I mentioned earlier.--JB001 04:42, 5 January 2007 (UTC)

This article is about conventional power plants burning fossil fuels. The large majority of power plants in the world are conventional plants. Their thermal efficiency is about 35%. If one wants to learn about other types of power plants, then one does exactly what you did ... that is, read the articles devoted to other types of power plants. Combined-cycle plants do indeed have higher efficiencies. And Cogeneration plants also have higher efficiencies.

The problem with Cogeneration is that there must be a nearby large need for heat. Not all power plants are in small European countries with nearby towns needing central district heating (and that for only the winter season).

I can assure you that if there is an economic justification for cogeneration, power plant developers and their engineers will certainly consider it. As for thermal pollution of rivers or other waterways, a good part of the steam condensing can be done with air-cooling rather than water-cooling ... and some power plants do utilize air-cooling. But again, in today's world, there must be an economic justification for doing so. - mbeychok 18:04, 5 January 2007 (UTC)

[edit] Re: 'waste heat' edit...

In the 'Steam Condensing' section, after my edit, here is an extract of what the article used to say:

The heat absorbed by the circulating cooling water in the condenser tubes must also be removed to maintain the ability of the water to cool as it circulates.

My edit has since been reversed by mbeychok, removing my reference to waste heat, who states that it is 'out of context', and that a cooling tower does not "produce" waste heat.

I would like to defend a reference being made to 'waste heat' in this article. In the 'waste heat' article, reference is made to cooling towers, so I do not think that it is out of context. The heat is ‘waste’ because energy has been expended in creating it, and yet no useful application is found for it – and it is simply dumped into the environment through the cooling towers.

It may not be intentional that a cooling tower ‘wastes’ heat, but in keeping the cooling water cool, that is effectively what it has to do. It is as much a product of its operation, as the cool water is.--JB001 02:15, 8 January 2007 (UTC)

JB001, with all due respect, I have no intention of getting into a discussion or debate with you about semantics. The water entering the cooling tower is just barely warm water at a temperature of about 120 °F (49 °C). There is no practical place to use such low level heat in a power plant. As you just admitted in a message on my talk page, you have a "bee in your bonnet" about wasting heat. That was clearly evident in our previous lengthy discussion just above. Having a "bee in your bonnet about not wasting heat" is a good thing ... but it can be carried to extremes. Yes, that heat removal in a cooling tower ends up in the atmosphere. But your edit linking it to an article on waste heat and your wording that the lost heat is "dumped into the environment" makes it sound as if power plants are deliberately doing something that is "wrong" of them. That is what I meant when I said that your edit "was out of context".

There are a lot of valid examples of foolish waste in this world ... just look at all of the unnecessarily large SUVs on the road wasting huge amounts of energy. Expend your efforts on those sorts of waste rather than worrying about the very low level heat rejected by cooling towers. Now, once again with due respect, I have to get back to more important work. - mbeychok 03:35, 8 January 2007 (UTC)

I propose that the article say the following:

The heat absorbed by the circulating cooling water in the condenser tubes must also be removed to maintain the ability of the water to cool as it circulates.

This is done by pumping the warm water from the condenser through either natural draft, forced draft or induced draft cooling towers (as seen in the image to the right) that reduce the temperature of the water, by 20–30 °F (11–17 °C), by evaporation - expelling waste heat to the atmosphere. The circulation flow-rate of the cooling water in a 500 MWe unit is about 225,000 US gallons per minute (14.2 m³/s) at full load.

Hopefully this is more agreeable, and it avoids the same wicked connotations of deliberately producing waste. I think it actually clarifies what is happening, and it is good to have convenient links to other related articles for people who are reading up on the subject.--JB001 09:57, 8 January 2007 (UTC)

That is agreeable with me. Happy New Year! - mbeychok 17:45, 8 January 2007 (UTC)

Jolly good then, 'tis done! Happy New Year to you too! :-) --JB001 09:00, 9 January 2007 (UTC)

[edit] Do we really need 4 articles on the same subject?

Wikipedia now has these 4 articles, all on the same subject:

Do we really need all of these? In my opinion, this sort of thing reflects badly on Wikipedia. What can we do to get these four articles merged?? - mbeychok 17:53, 23 January 2007 (UTC)

[edit] Is this correct?

It is stated that: "Nuclear power plants generally cannot reheat process steam due to safety requirements for isolation from the reactor core. This limits their thermodynamic efficiency to the order of 34–37%."

So far every diagram I have found on the net shows that steam is cooled and re-heated. Examples:

—The preceding unsigned comment was added by Vynbos (talk • contribs) 10 February 2007 (UTC).

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