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PostPosted: Aug 04, 2016 11:13 pm 
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Arctic to Antarctic could take a month by ship.
Much wiser to get a closer standby. They ultimately managed on their own!


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PostPosted: Aug 04, 2016 11:35 pm 
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"Yamal is one of the Russian "Arktika" family of icebreakers, the most powerful icebreakers in the world. These ships must cruise in cold water to cool their reactors[not in citation given], so they cannot pass through the tropics to undertake voyages in the Southern hemisphere."
https://en.wikipedia.org/wiki/Yamal_(icebreaker)

"Built entirely for service in the Arctic seas, the Yamal is unable to voyage to the Antarctic because of her cooling system. This requires that it be supplied with cold sea water to operate properly, if the ship were to voyage to Antarctica it would have to cross the equator and sail through the tropics where the water is most definitely warm. Hence the Yamal and her sister ships are confined to the Northern polar region."
http://www.coolantarctica.com/Antarctic ... reaker.php

And some more for you to read.

http://www.google.ca/url?sa=t&rct=j&q=& ... gu5Mfd8nRA

https://www.iaea.org/NuclearPower/Downl ... Fadeev.pdf

http://www.liquisearch.com/arktika_clas ... a_reactors

http://www.rosatomflot.ru/index.php?menuid=33&lang=en

http://www.world-nuclear.org/informatio ... lants.aspx

http://www.sciencedirect.com/science/ar ... 3315300814

The reason why people think that a nuclear powered icebreakers cannot cross the tropics is because of the cooling system in the reactor as I explained before. You are not going to get any where near 50 C in the middle of the Pacific ocean. "Operate properly" meaning, it can run at full power. There are no side effects using warmer water for cooling other then loss of power. As I said before, it would be a 12% drop in power using 30 C temperature water rather then 0 C. That is the only difference.

If Hawaii had nuclear energy, they could increase the efficiency of the power plant by 8-10% just by dropping a large pipe down 1500 meters and suck up 4 C cooling water. And it dos not have to be a nuclear power plant. Any type of plant would be more efficient.


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PostPosted: Aug 04, 2016 11:58 pm 
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jagdish wrote:
Arctic to Antarctic could take a month by ship.
Much wiser to get a closer standby. They ultimately managed on their own!


I totally agree. Kind of silly for Russia to call home 8000 miles for help, when there is a Chinese, a Aussie, and a US ship that could help just 800 miles away.


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PostPosted: Aug 05, 2016 1:55 am 
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Wilson wrote:
There are no side effects using warmer water for cooling other then loss of power. As I said before, it would be a 12% drop in power using 30 C temperature water rather then 0 C. That is the only difference.

You missed the part where without sufficiently cool water the crew compartments can reach dangerous temperatures. The power plant on board produces potentially over 170MW thermal, without enough cold water to cool the ship the crew compartments will become unbearably hot. With the reduced power plant output the crew will be exposed to this heat for weeks while it travels to the Antarctic.

Wilson wrote:
You are not going to get any where near 50 C in the middle of the Pacific ocean.

That 50C temperature was not in reference to the water temperature but the temperature within the crew compartments on board if it was to travel in tropical waters. The water is used to cool the crew too, not just the reactor.

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PostPosted: Aug 05, 2016 2:27 am 
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Wilson wrote:
jagdish wrote:
Arctic to Antarctic could take a month by ship.
Much wiser to get a closer standby. They ultimately managed on their own!

I totally agree. Kind of silly for Russia to call home 8000 miles for help, when there is a Chinese, a Aussie, and a US ship that could help just 800 miles away.

If Russia has year-round Antarctic stations then one would assume they'd have a heavy icebreaker as capable as anything the US has but they do not. Had there been any Russian icebreakers in the area when that Russian research vessel was icebound chances are they would have been as unsuccessful in freeing her as the Chinese, Australian, and French ships were. Russia has several warm water capable medium icebreakers but their heavy icebreakers are Arctic bound. Even so few or none of their icebreakers have variable pitch propellers which limits their ability to ram through the large ice peaks common in Antarctic waters.

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Disclaimer: I am an engineer but not a nuclear engineer, mechanical engineer, chemical engineer, or industrial engineer. My education included electrical, computer, and software engineering.


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PostPosted: Aug 05, 2016 7:59 am 
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Quote:
That 50C temperature was not in reference to the water temperature but the temperature within the crew compartments on board if it was to travel in tropical waters. The water is used to cool the crew too, not just the reactor.


https://earth.nullschool.net/#current/w ... 148,11.377

See live map above, you do not have any air temperatures above 30 C in the middle of the Pacific ocean at this moment. That happens closer to the coast lines. There is just to much water to cool the air. Just click on the map and it will give you air temperature. 22.33N, 149.64E is the hot spot in the Pacific right now. The Persian Gulf (air temperature) is 46.4 C at the moment. The reason why the Persian gulf is so hot is because its land locked on three sides. Less ocean water to cool the surrounding area.


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PostPosted: Aug 05, 2016 8:56 am 
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Cooling a crew compartment with 5C water is an awful lot more efficient than cooling with 25C water.
All the intakes, pumps and pipework are sized for small flows of very cold water and not large flows of warm water


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PostPosted: Aug 05, 2016 2:34 pm 
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Another thing to remember is that turbines often don't work well with a high back-pressure. Rather than spinning in an effective vacuum, the last stages will be spinning in a significant partial pressure. This can put a lot of drag on them, reducing efficiency and power output to a much greater extent than simple thermodynamics would suggest.

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PostPosted: Aug 05, 2016 9:01 pm 
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Wilson wrote:
See live map above, you do not have any air temperatures above 30 C in the middle of the Pacific ocean at this moment. That happens closer to the coast lines. There is just to much water to cool the air.

The people that designed, built, and operate the ship say that the cabin temperatures will likely exceed 50C if the ship were to travel in tropical waters. You can argue all you like but I'll take their word over yours every time.

Also, assuming what you say is true and the cabin temperatures will not exceed 30C, they will be traveling in an area where relative humidity will be around 80%. 30C and 80% humidity is considered a rather dangerous working environment, people risk heat exhaustion working in such conditions. They might be able to find a path where the temperatures are a few degree C cooler, by following prevailing arctic winds perhaps, but that's still a very uncomfortable and potentially dangerous voyage for the crew.

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Disclaimer: I am an engineer but not a nuclear engineer, mechanical engineer, chemical engineer, or industrial engineer. My education included electrical, computer, and software engineering.


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PostPosted: Aug 06, 2016 7:28 pm 
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Quote:
The people that designed, built, and operate the ship say that the cabin temperatures will likely exceed 50C if the ship were to travel in tropical waters. You can argue all you like but I'll take their word over yours every time.


Tropical oceans encircle Earth in an equatorial band between the Tropic of Cancer (23.5° North latitude) and the Tropic of Capricorn (23.5° South latitude). *

Read more: http://www.waterencyclopedia.com/Oc-Po/ ... z4GbKpaEnr

Tropics could mean either through the Persian gulf or the middle of the Pacific. One can be 50 C, the other never, and they are both in the tropics.

Please provide reference where cabin temperatures can exceed 50 C in the middle of the Pacific ocean.


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PostPosted: Aug 06, 2016 8:24 pm 
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Wilson wrote:
Please provide reference where cabin temperatures can exceed 50 C in the middle of the Pacific ocean.


I did cite my source when I pointed that out in the first place. I gave the link to the Wikipedia article on the Arktika that was launched this year.
https://en.wikipedia.org/wiki/Arktika_(2016_icebreaker)
Wikipedia is a secondary source but they give their primary source.
http://rbth.com/science_and_tech/2014/01/22/icehunters_russian_conquerors_of_the_north_pole_33439.html

Quote:
Since these vessels were originally designed to operate in the cold Arctic waters, they cannot traverse to the Antarctic: in the course of such a voyage, the temperature in some of their compartments would rise to 50 degrees Celsius even at low reactor power settings.


I see that you list your occupation as welder in your profile. Because of your work you must understand that heat does not dissipate immediately, it takes time. If heat did dissipate as quickly as you claim then you would never be able to melt the wire on your welder to create a bead, the rest of the steel would soak up the heat. The reactor on these nuclear powered icebreakers operate at 300C, that heat will "soak" into the surrounding compartments until it reaches an equilibrium with the water and air outside the ship. The people that built the ship have computed that they'd see 50C in many compartments even if the reactor was operating at minimal power. At reduced power the ship would be traveling slower than it's max rated 22 knots, meaning spending many days in this heat. Increasing the power means reducing the time spent in the warm waters but also increased heat in the ship's compartments.

Again, even if what you claim were to be true the crew would be spending many days in 30C heat and 80% humidity, that is a potentially dangerous working environment and certainly uncomfortable.

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Disclaimer: I am an engineer but not a nuclear engineer, mechanical engineer, chemical engineer, or industrial engineer. My education included electrical, computer, and software engineering.


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PostPosted: Aug 06, 2016 9:47 pm 
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Quote:
I did cite my source when I pointed that out in the first place. I gave the link to the Wikipedia article on the Arktika that was launched this year.
https://en.wikipedia.org/wiki/Arktika_(2016_icebreaker)


I see your point. Next time, I will read your references fully.

Quote:
even at low reactor power settings.
is the phrase that spells it out that its internal heat rather than external heat that heats the compartments.

Good example with the welding that you gave.

Looks like they made the compartments to cool with 4 C water rather than 30 C water.


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