Thank you so much!!! Before watching this video I didn't understand the operation of natural draft cooling towers. My exam is this saturday and your video was really really helpfull!
2:24 Structural reason for the hyperboloid: There is a pressure differential between the interior and exterior that is structurally significant at this scale. Unlike a cylinder, this shape is self-supporting against local buckling that would otherwise crush the shell structure inward. In a sense, instead of relying on an unstable compressive arch shape in the horizontal plane as a cylinder does, it is supported by a tensile hammock-shape in the vertical plane.
Nice video. Thank you. We were taken on a trip around a working 2GW power station in school many years ago (actually walking around the working areas - coal mills, peeking inside the running boilers, the generator room etc, not just some sanitised 'visitor centre' and it was most definitely my best school day ever. I doubt today's tours would be quite so hands-on! Anyway a question that has stayed at the back of my mind is they were boasting about the temperature of the water returned to the river was less than 0.5°C higher than when it was extracted. Why would they be returning water to the river on a regular basis?
Weird. It's not a one pass system, there should only be makeup water and blowdown depending on the type of cooling tower. Blowdown amount depends on the cycles of concentration. I will have a think about it, thanks for the question! Don't forget to check out the new channel, it's more active and the videoa are a lot better.
Hi, the water from the river/lake is mixed with cooled water recovered while cooling down in this process? Is this water safe to return to a lake or a river?
I appreciate exhaust steam from the turbine needs to be condensed so it can be re-heated but why is warm water cooled (as the video explains) and then re-heated. Surely re-heating warm water rather than cooled water is more efficient.
Good question. The most important thing to keep in mind is how the steam is cooled. You can cool using a large volumetric flow of water with a small delta T (delta T = temperature difference between cooling water system and steam system), or a smaller volumetric flow of water with a larger delta T. Assuming the condenser remains the same, the actual cooling effect is the same for both these scenarios, but the volume of water required for cooling is the difference. The condenser is only so big and the steam needs to be condensed quickly. So if you have a small delta T, you would need the cooling water flow to be increased considerably (more flow is more cooling) compared to when you have a larger delta T. I am guessing that pumping 1,000 tonnes of water an hour is less expensive than pumping 10,000 tonnes of water an hour, and it may be another reason (electricity costs) power plants like to maintain a decent delta T. Assuming a constant flow rate, a condenser operating with a higher delta T has a higher cooling capacity than if operating with a lower delta T. This means the condenser can be smaller in design, this maybe a design limiting factor. Coming back to your question (sorry, I get carried away)... Cooling with HEATED cooling water represents a smaller delta T when compared to cooling with COOLED cooling water, so you need to increase the flow or make the condenser larger if using a smaller delta T. But, why bother? Keep the delta T large and you can have a smaller condenser, or, keep the condenser the same size and use less water. Either way, a larger delta T is useful. The trick is to not make the delta T too large, because you do not want to thermal shock the condenser and burst tubes (happens...). Does that help? There is an article here you might find interesting: www.overclockers.com/water-cooling-flow-rate-and-heat-transfer/ FROM THE ARTICLE There is an elementary equation from basic thermodynamics that states that the rate of heat transfer (Q) equals the mass flow rate (M) times a Constant (the specific heat of water) times the Delta T (fluid temp out minus fluid temp in): Q = M x C x Delta T
Prior to reheating the water, the pressure must be increased to have a difference in pressure across the turbine. This allows for the mechanical work to be extracted. If you pressurize the warm water without cooling it, the pump would have to put in the same amount of energy you would get out of the turbine and the system would produce no additional energy. The working fluid must make its way around a cycle in a pressure-volume diagram to get work out. Great question! I hope this helps! :D
Hello budyy. I appreciate your hardworking more than you will ever know ! Literally no words can explain my satisfaction. I had to design a natural draft cooling tower to graduate this year man thanks a bunch again :) But i have some problems to draw this cooling tower. Where can i find fill materials existingly available ? Im gonna draw this tower on SolidWorks app. Thanks in advance :)
+akki01 Will try to get around to it. I am more mechanical and electrical, but can probably find the relevant design and construction info to make a video. Will do my best. Thanks for watching!
Hello that was fantastic video. In thermodynamics course our professor ask us " why we use cooling towers instead of heat exchanger or something? It is too much cost we still use it. Why?" We answered all answers but he said "you re right but that is not I want. " And I asked him privately he said " it is about evaporation." What it would be? Please help me.
Some of the cooling water will evaporate in the cooling tower due to the pressure drop after leaving the spray nozzles and due to its coming into contact with the ambient air (the pressure of which affects the rate of evaporation). The effect of evaporation cools the system further because it represents a pressure drop and change of state (read about latent and sensible heat to know more). Remember that a pressure drop and volume increase also represent a temperature decrease (this is how a thermostatic expansion valve works in a refrigeration system). A pressure increase has a volume decrease and temperature increase (like in a combustion engine during the compression stroke). In short, evaporation creates an additional cooling effect other than just the heat exchanged between the water and air. At least, that is my opinion...:) If you can, try to get a hold of 'Standard Handbook of Powerplant Engineering', go to page 2.140, it has all the thermodynamic equations relating to the heat exchange for cooling towers and the equation they use to account for evaporation.
thanks for answering. According to my research , way your look is right. Evaporation creates an additional cooling effect. I got that book but there is only 1.019 pages. Thanks for advice
if you are still interested, i found the answer. thanks a lot! www.power-eng.com/articles/print/volume-114/issue-7/Features/cooling-tower-heat-transfer-101.html
The shape increases efficiency because it increases the speed of the air as it travels through the tower. I believe it's also cheaper to build this shape tower rather than a traditional cylindrical shaped tower.
Hi, You are the second person to ask about the structural design so I will try to see if I can make a video at some point in the future, I did some work with fracture mechanics so hopefully it wont take me too long to understand the important bits...hopefully... No promises but I will see what I can do. All the best and thanks for watching, Jon
I wouldn't actually know to be honest. I imagine a big risk with having that type of setup could potentially be radioactive contamination of the cooling water.
+Phuon lytho You can, but it doesn't normally make sense. Fans consume electricity and electricity costs money. The tower delivers enough cooling capacity without needing to use fans, it's designed that way. There are instances though where fans might be installed, Especially if the cooling capacity increases (power plant MW size increased) and you can get the additional cooling capacity by installing fans rather than a building a whole new tower. Hope that helps.
The model will be getting updated within the next few months. It is one of the first models that were created so it needs to be updated (will be a lot better). I will add something where the labels can be hidden or shown. I have not forgot about making a civil engineering video for the tower, just have not had a chance to get around to it yet.
so the one with basically a chimney in the middle, would only be used by a coal plant? since a nuclear power station wouldn't burn anything. i wonder why the 2 cooling towers at Chernobyl (were never used, or even finished construction) have a giant pipe in the middle like that.
Interesting. Maybe for the fire tube boilers (not even sure they have auxi boilers because I have never surveyed a nuclear power station) ? I would have to check on that, I will get back to you. Thanks for the observation and comment. Don't forget to checkout the new channel! (search 'savree 3d')
@@3dknowledge i have been pretty much stuck on this channel and your new one watching all the amazing video's you've made. really educational and fun to just absorb random facts about things that you might be interacting with or seeing on a daily basis without ever thinking about how they work, or what they exactly do.
@@3dknowledge sorry for the late reply i was kind of busy this week, again i think im just in love with your channel :D the 3D models are very well made, and you explain things very well. regarding the cooling towers at chernobyl, this is what it looks like www.google.com/maps/@51.3776036,30.1331149,3a,79.9y,241.24h,72.76t/data=!3m8!1e1!3m6!1sAF1QipMgFsZ0M5FLohK3WaVaY91pnRGftjIqE030dDuj!2e10!3e11!6shttps:%2F%2Flh5.googleusercontent.com%2Fp%2FAF1QipMgFsZ0M5FLohK3WaVaY91pnRGftjIqE030dDuj%3Dw203-h100-k-no-pi-0-ya240.73355-ro-0-fo100!7i8704!8i4352 its a 360' picture so you can look around, it appears this tower has 2 of those pipes, so im not quite sure what they were for, or even if they are chimney's in the first place.
NEW CHANNEL FOR ALL FUTURE VIDEOS! PLEASE SUBSCRIBE FOR MORE EDUCATIONAL ENGINEERING VIDEOS!
ua-cam.com/channels/osExgfjj-DhMJXnQd2Y4gA.html
This was really well explained. I've been trying to find a video that does exactly what this one does for a long time
+GB UK
Thanks. Much appreciated. Stay tuned and hopefully you will see more good content! ;)
Jon
ㆍ
Thank you so much!!!
Before watching this video I didn't understand the operation of natural draft cooling towers. My exam is this saturday and your video was really really helpfull!
This is simply magnificient.
Thanks! If you like this, you will live the new channel. Checkout the savree 3d channel for new videos. We are producing 2-3 a week.
Excellent video, easy to follow and understand. Thanks!
Thanks! Means a lot to me, knowing that people are finding these videos useful.
2:24 Structural reason for the hyperboloid: There is a pressure differential between the interior and exterior that is structurally significant at this scale. Unlike a cylinder, this shape is self-supporting against local buckling that would otherwise crush the shell structure inward. In a sense, instead of relying on an unstable compressive arch shape in the horizontal plane as a cylinder does, it is supported by a tensile hammock-shape in the vertical plane.
Great video, although I can't help but wonder why they use a circular spray pattern and not something more efficient like hex tiling or Vogel's model?
Always wanted to know how these work thanks for the info great video big thanks
Thanks for the nice feedback!
Nice video. Thank you. We were taken on a trip around a working 2GW power station in school many years ago (actually walking around the working areas - coal mills, peeking inside the running boilers, the generator room etc, not just some sanitised 'visitor centre' and it was most definitely my best school day ever. I doubt today's tours would be quite so hands-on!
Anyway a question that has stayed at the back of my mind is they were boasting about the temperature of the water returned to the river was less than 0.5°C higher than when it was extracted.
Why would they be returning water to the river on a regular basis?
Weird. It's not a one pass system, there should only be makeup water and blowdown depending on the type of cooling tower. Blowdown amount depends on the cycles of concentration. I will have a think about it, thanks for the question!
Don't forget to check out the new channel, it's more active and the videoa are a lot better.
Hi, the water from the river/lake is mixed with cooled water recovered while cooling down in this process? Is this water safe to return to a lake or a river?
I am wondering how small the Natural Draft Hyperbolold towers can be built? Do they become less efficient when they get shorter?
good information..and the way you explained is best one ..make more and more videos..
Thanks. Nice to get feedback, I really appreciate it. Next video will be online within a week.
I hear you! More videos coming!
Thanks, man! Tomorrow is my exam. You save me.
No problem! Thanks for watching. 😀
This was in paper xD
I appreciate exhaust steam from the turbine needs to be condensed so it can be re-heated but why is warm water cooled (as the video explains) and then re-heated. Surely re-heating warm water rather than cooled water is more efficient.
Good question.
The most important thing to keep in mind is how the steam is cooled. You can cool using a large volumetric flow of water with a small delta T (delta T = temperature difference between cooling water system and steam system), or a smaller volumetric flow of water with a larger delta T. Assuming the condenser remains the same, the actual cooling effect is the same for both these scenarios, but the volume of water required for cooling is the difference.
The condenser is only so big and the steam needs to be condensed quickly. So if you have a small delta T, you would need the cooling water flow to be increased considerably (more flow is more cooling) compared to when you have a larger delta T. I am guessing that pumping 1,000 tonnes of water an hour is less expensive than pumping 10,000 tonnes of water an hour, and it may be another reason (electricity costs) power plants like to maintain a decent delta T.
Assuming a constant flow rate, a condenser operating with a higher delta T has a higher cooling capacity than if operating with a lower delta T. This means the condenser can be smaller in design, this maybe a design limiting factor.
Coming back to your question (sorry, I get carried away)...
Cooling with HEATED cooling water represents a smaller delta T when compared to cooling with COOLED cooling water, so you need to increase the flow or make the condenser larger if using a smaller delta T. But, why bother? Keep the delta T large and you can have a smaller condenser, or, keep the condenser the same size and use less water. Either way, a larger delta T is useful. The trick is to not make the delta T too large, because you do not want to thermal shock the condenser and burst tubes (happens...).
Does that help?
There is an article here you might find interesting:
www.overclockers.com/water-cooling-flow-rate-and-heat-transfer/
FROM THE ARTICLE
There is an elementary equation from basic thermodynamics that states that the rate of heat transfer (Q) equals the mass flow rate (M) times a Constant (the specific heat of water) times the Delta T (fluid temp out minus fluid temp in):
Q = M x C x Delta T
Prior to reheating the water, the pressure must be increased to have a difference in pressure across the turbine. This allows for the mechanical work to be extracted. If you pressurize the warm water without cooling it, the pump would have to put in the same amount of energy you would get out of the turbine and the system would produce no additional energy. The working fluid must make its way around a cycle in a pressure-volume diagram to get work out. Great question! I hope this helps! :D
Hello budyy. I appreciate your hardworking more than you will ever know ! Literally no words can explain my satisfaction. I had to design a natural draft cooling tower to graduate this year man thanks a bunch again :) But i have some problems to draw this cooling tower. Where can i find fill materials existingly available ? Im gonna draw this tower on SolidWorks app. Thanks in advance :)
Thanks man. I appreciate it. Make sure you subscribe, that's all I ask! :) congrats on graduating!
3D-knowledge You are my hero ❤️
That was a awesome video...
Can you please also focus on design and build quality .. as m a civil engineering student...
+akki01
Will try to get around to it. I am more mechanical and electrical, but can probably find the relevant design and construction info to make a video. Will do my best. Thanks for watching!
We have a few cooling towers here in southwest Ohio, Cincinnati area!
Any chance of putting a graffiti 3D-knowledge.com logo on them? 😀
Hello that was fantastic video. In thermodynamics course our professor ask us " why we use cooling towers instead of heat exchanger or something? It is too much cost we still use it. Why?" We answered all answers but he said "you re right but that is not I want. " And I asked him privately he said " it is about evaporation." What it would be? Please help me.
Some of the cooling water will evaporate in the cooling tower due to the pressure drop after leaving the spray nozzles and due to its coming into contact with the ambient air (the pressure of which affects the rate of evaporation). The effect of evaporation cools the system further because it represents a pressure drop and change of state (read about latent and sensible heat to know more).
Remember that a pressure drop and volume increase also represent a temperature decrease (this is how a thermostatic expansion valve works in a refrigeration system). A pressure increase has a volume decrease and temperature increase (like in a combustion engine during the compression stroke).
In short, evaporation creates an additional cooling effect other than just the heat exchanged between the water and air. At least, that is my opinion...:)
If you can, try to get a hold of 'Standard Handbook of Powerplant Engineering', go to page 2.140, it has all the thermodynamic equations relating to the heat exchange for cooling towers and the equation they use to account for evaporation.
thanks for answering. According to my research , way your look is right. Evaporation creates an additional cooling effect. I got that book but there is only 1.019 pages. Thanks for advice
after nozzle sprayed water , what is pressure of that water?
if you are still interested, i found the answer. thanks a lot! www.power-eng.com/articles/print/volume-114/issue-7/Features/cooling-tower-heat-transfer-101.html
Hi, thanks for this. I did not get your message for some reason, sorry. To answer your question, the water has no pressure after leaving the nozzle.
Why do cooling towers have such a iconic shape? Is it due to efficiency, or is this a structural decision?
The shape increases efficiency because it increases the speed of the air as it travels through the tower. I believe it's also cheaper to build this shape tower rather than a traditional cylindrical shaped tower.
any Idea about the structural design of natural draught cooling tower.If you know plzz guide me
Hi,
You are the second person to ask about the structural design so I will try to see if I can make a video at some point in the future, I did some work with fracture mechanics so hopefully it wont take me too long to understand the important bits...hopefully...
No promises but I will see what I can do.
All the best and thanks for watching,
Jon
Isnt there an cooling tower that there is pipes underneat submerged in water that is used in nuclear power plants?
I wouldn't actually know to be honest. I imagine a big risk with having that type of setup could potentially be radioactive contamination of the cooling water.
Why we don't use fan?
+Phuon lytho
You can, but it doesn't normally make sense. Fans consume electricity and electricity costs money. The tower delivers enough cooling capacity without needing to use fans, it's designed that way. There are instances though where fans might be installed, Especially if the cooling capacity increases (power plant MW size increased) and you can get the additional cooling capacity by installing fans rather than a building a whole new tower.
Hope that helps.
It would cost a lot of money to make a giant fan for a tower this size
Forced type ?
please name the supporting structures in this cooling tower. I mean the coloumn like shapes are there.please Name them.
The model will be getting updated within the next few months. It is one of the first models that were created so it needs to be updated (will be a lot better). I will add something where the labels can be hidden or shown. I have not forgot about making a civil engineering video for the tower, just have not had a chance to get around to it yet.
so the one with basically a chimney in the middle, would only be used by a coal plant? since a nuclear power station wouldn't burn anything. i wonder why the 2 cooling towers at Chernobyl (were never used, or even finished construction) have a giant pipe in the middle like that.
Interesting. Maybe for the fire tube boilers (not even sure they have auxi boilers because I have never surveyed a nuclear power station)
? I would have to check on that, I will get back to you. Thanks for the observation and comment.
Don't forget to checkout the new channel! (search 'savree 3d')
@@3dknowledge i have been pretty much stuck on this channel and your new one watching all the amazing video's you've made.
really educational and fun to just absorb random facts about things that you might be interacting with or seeing on a daily basis without ever thinking about how they work, or what they exactly do.
Cool! Glad you like it. There will be a new video online soon, I'm just waiting for a 3d model so I can finish it.
Also starting to develop this page more. A new battery course comes soon and then a bearings course.
savree.com/en/video-courses/
@@3dknowledge sorry for the late reply i was kind of busy this week, again i think im just in love with your channel :D
the 3D models are very well made, and you explain things very well.
regarding the cooling towers at chernobyl, this is what it looks like www.google.com/maps/@51.3776036,30.1331149,3a,79.9y,241.24h,72.76t/data=!3m8!1e1!3m6!1sAF1QipMgFsZ0M5FLohK3WaVaY91pnRGftjIqE030dDuj!2e10!3e11!6shttps:%2F%2Flh5.googleusercontent.com%2Fp%2FAF1QipMgFsZ0M5FLohK3WaVaY91pnRGftjIqE030dDuj%3Dw203-h100-k-no-pi-0-ya240.73355-ro-0-fo100!7i8704!8i4352
its a 360' picture so you can look around, it appears this tower has 2 of those pipes, so im not quite sure what they were for, or even if they are chimney's in the first place.
Why pH increased in NDCT
i couldnt continue past "not your mate phil"..