How Do Submarines Dispose of Waste Heat?

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Discussion Overview

The discussion centers on how nuclear submarines and air independent propulsion submarines manage the disposal of waste heat generated by their power plants, particularly in the context of high pressure environments and the need for stealth. Participants explore various methods and implications related to heat dissipation and detection technologies.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested
  • Historical

Main Points Raised

  • Some participants propose that waste heat is discharged to the surrounding water via condensers and service water systems.
  • Others mention the use of heat exchangers capable of handling high pressure.
  • There is a question regarding the absorption of infrared (IR) radiation in seawater and its implications for stealth.
  • One participant speculates that sound reflection off temperature gradients caused by heat released from submarines could pose a stealth problem.
  • Another participant raises the distinction between passive listening and active sonar in the context of submarine detection.
  • Some contributions discuss the potential use of satellite technology for detecting submarines through non-acoustic means, including infrared and synthetic aperture radar.
  • A later reply questions whether the design of submarines might be easier due to the external pressure of the ocean compared to land-based units.
  • There are discussions about historical satellite reconnaissance efforts and their relevance to submarine detection, with no consensus on the effectiveness of these technologies.
  • One participant expresses a personal interest in military tactics and the historical context of submarine detection technologies.

Areas of Agreement / Disagreement

Participants express a range of viewpoints on the methods of waste heat disposal and the implications for stealth, with no clear consensus reached on the effectiveness of different approaches or technologies discussed.

Contextual Notes

Some discussions touch on the limitations of current understanding regarding the interaction of heat with sonar and IR detection, as well as the historical context of submarine detection technologies, but these remain unresolved.

Who May Find This Useful

This discussion may be of interest to individuals exploring military technology, submarine engineering, and the physics of underwater acoustics and thermal dynamics.

Delta Force
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How do nuclear submarines (and also newer technologies such as air independent propulsion submarines) get rid of the waste heat generated by their power plants given the high pressure environment they work in and their need for stealth?
 
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Delta Force said:
How do nuclear submarines (and also newer technologies such as air independent propulsion submarines) get rid of the waste heat generated by their power plants given the high pressure environment they work in and their need for stealth?

A condenser and service water systems. The heat gets discharged to the water around them.
 
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...via heat exchangers that can handle the pressure.
 
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Delta Force said:
How do nuclear submarines (and also newer technologies such as air independent propulsion submarines) get rid of the waste heat generated by their power plants given the high pressure environment they work in and their need for stealth?
With respect to stealth, what is the absorption of IR in seawater like? :smile: How does that affect your question?

ftp://misclab.umeoce.maine.edu/users/optics/classFTP2015/Labs/Lab2_resources/Pegauetal1997.pdf
 
berkeman said:
With respect to stealth, what is the absorption of IR in seawater like? :smile: How does that affect your question?

ftp://misclab.umeoce.maine.edu/users/optics/classFTP2015/Labs/Lab2_resources/Pegauetal1997.pdf
My guess: sound reflection off temperature gradients in the water set up by heat released from a sub is the stealth problem.
 
mheslep said:
My guess: sound reflection off temperature gradients in the water set up by heat released from a sub is the stealth problem.
Interesting thought. Are you talking about normal ocean sounds having their propagation modified by the thermal trail behind the sub? Or a return change for active sonar pings? But if active sonar pings, those should pick up the sub unless they have some amazing sound absorbing coating, no?

Plus, I would guess that most of the movements of stealthy subs are below the natural thermocline layer, so that's wny I assumed the OP was asking about optical IR detection...

http://oceanservice.noaa.gov/facts/thermocline.html
 
Passive listening, not active.
 
http://www.atimes.com/atimes/China/LE13Ad01.html

Detecting submarines via satellite is a form of Non-Acoustic Anti-Submarine Warfare (NAASW). Lasers, infrared and other detectors and synthetic aperture radar (SAR) in space may be used as part of this NAASW activity. Satellites might see subtle undersea disturbances caused by submarines, watch wave patterns on or beneath the sea surface, or detect subtle variations in ocean temperature.
 
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jim hardy said:
...via heat exchangers that can handle the pressure.

Oh wait, the secondary coolant loop is already pressurized. Since water is a good heat exchanger and since the ocean is applying more external pressure than a land based unit using the atmosphere as a heat sink doesn't that mean the design is in some respects easier?
 
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jim hardy said:

Might the Soviet US-A (Western designation Radar Ocean Reconnaissance Satellite/RORSAT) series satellites and the TOPAZ reactor powered Kosmos 1818 and Kosmos 1867 satellites have been used in that role, at least with the later units? The US-A series orbited Earth very closely and getting any useful information from a high altitude naval radar would have required development of look-down capability to eliminate clutter.

The United States didn't deploy synthetic aperture radar satellites until many years after the Soviets put theirs up, but the United States and NATO could far more easily ring the ocean with sound detection equipment and early Soviet submarines were notoriously noisy. The Soviets were at a disadvantage in lacking friendly areas to base sound detection equipment out of and having to hunt submarines that were far quieter.

This is getting more into radar physics than nuclear power, but I'm wondering if this is something that the Soviets might have been trying for with their naval reconnaissance satellites.
 
  • #11
Delta Force said:
Might the Soviet US-A (Western designation Radar Ocean Reconnaissance Satellite/RORSAT) series satellites and the TOPAZ reactor powered Kosmos 1818 and Kosmos 1867 satellites have been used in that role, at least with the later units? The US-A series orbited Earth very closely and getting any useful information from a high altitude naval radar would have required development of look-down capability to eliminate clutter.

The United States didn't deploy synthetic aperture radar satellites until many years after the Soviets put theirs up, but the United States and NATO could far more easily ring the ocean with sound detection equipment and early Soviet submarines were notoriously noisy. The Soviets were at a disadvantage in lacking friendly areas to base sound detection equipment out of and having to hunt submarines that were far quieter.

This is getting more into radar physics than nuclear power, but I'm wondering if this is something that the Soviets might have been trying for with their naval reconnaissance satellites.
Why the fascination with trying to tap other smart folks for ideas about military tactics? Are you thinking of writing a book? We have a different sub-forum for that...
 
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  • #12
berkeman said:
Why the fascination with trying to tap other smart folks for ideas about military tactics? Are you thinking of writing a book? We have a different sub-forum for that...

I have thought of writing something about the United States Atomic Energy Commission, especially its work on environmental studies and alternative energy. This question is really more of personal interest because I didn't know synthetic aperture radar could be used to detect submarines.

I'm interested in alternate history/counterfactual history (leaning closer to the "hard" side of things and counterfactual history) and want to make sure that I get the details right. I respect that this is a physics forum and not a politics or history forum, but I suppose without context some of my questions must seem a bit strange.
 
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  • #13
Well I'm sure no expert just a curious amateur.

Tom Clancy fascinates me and sometimes i check him against Jane's just out of curiosity.
I just finished "Cardinal of the Kremlin" . When i checked Google Maps , Clancy's Russian 'satellite killer lasers' were exactly where he described them in 1988 .
DushanbeLasers.jpg


I know, it's a thirty year old book .. i really enjoyed it.
 
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