00X/004 future nuclear CATOBAR carrier thread


FairAndUnbiased

Captain
Registered Member
It is getting more confusing. I don't even know what you are trying to say now.

EMALS release the high power during launch, it draws lower power over a longer time from the grid. So there is difference of powers.

Steam reservoir releases high power during launch, it draws steam over a longer time from the boilers. There is difference too.

Electrical energy is just like heat energy in steam. Steam reservoir acts exactly like flywheels in EMALS. The amount of heat energy released during launch is the high instantaneous power, the drawing of heat energy from the boilers over a longer time is the continuous power.


matching the load is the work of the flywheels which are energy storage. The steam system has the steam reservoir which is another type of energy storage.

As said above, in steam catapult the reservoir is doing the same job as matching different load.


of course not, because there is no electrical energy to begin with.

So there is still energy to store. What is the difference then? You store different type of energy by different means.

There is in steam storage as explained above. Flywheel charging between launches is like you accumulate and store steam between launches. Both will draw portion of energy from the source.

Neither is it any easier for any other type of heat engines. This is actually proven by all types of power generation plant, include the GT powered Type 45.

You can not indefinitely store steam. It will cool over time loosing energy. Flywheel on the other hand loose energy in a slower rate, therefor able to store energy for a longer time.

Steam is a physical media, it stores energy in the form of excited molecules. Flywheel is a physical media, it stores energy in the form of rotating momentum. Electricity is the movement of electrons. It is not energy but the phenomenon of energy transmission. I have a feeling that you equated Steam to Energy and Electricity to Energy, therefor the confusions.
Uh I did no such thing. The problem of supply demand matching in electrical power engineering is well documented and is why grid scale energy storage is still an unsolved question. The current way to deal with supply and demand matching in civil electrical grids is through generation capability dispatching.

Flywheels are great but you previously quoted base load cruising power demand as 30% of peak. There is no electricity grid in the world where anywhere near 70% of peak demand can be stored. Every electricity grid in the world uses demand following and generation dispatch, not storage, to balance out supply and demand. Proof: there are no flywheels at 500 MW commercial power plants to store energy for peak demand.

Steam energy storage does not have such supply demand matching problems. You can add steam to a reservoirs and it doesn't have to be matched by consumption. I'm not sure how to be more clear on this.

My questions come from this point of view, comparing the carrier electrical grid to a commercial civilian grid of equal generating capability. If this is something that is inappropriate then I have nothing to say.

Here are some resources about generation dispatch:

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taxiya

Brigadier
Registered Member
Uh I did no such thing. The problem of supply demand matching in electrical power engineering is well documented and is why grid scale energy storage is still an unsolved question. The current way to deal with supply and demand matching in civil electrical grids is through generation capability dispatching.

Flywheels are great but you previously quoted base load cruising power demand as 30% of peak. There is no electricity grid in the world where anywhere near 70% of peak demand can be stored. Every electricity grid in the world uses demand following and generation dispatch, not storage, to balance out supply and demand. Proof: there are no flywheels at 500 MW commercial power plants to store energy for peak demand.

Steam energy storage does not have such supply demand matching problems. You can add steam to a reservoirs and it doesn't have to be matched by consumption. I'm not sure how to be more clear on this.

My questions come from this point of view, comparing the carrier electrical grid to a commercial civilian grid of equal generating capability. If this is something that is inappropriate then I have nothing to say.

Here are some resources about generation dispatch:

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If you did not make such confusion, that is great, it was only my feeling.

Please keep focus on the catapult subject. My point was that there is equal issue of load balancing/matching work in both EMALS and Steam Catapult system but only manifested in different forms. To which you disagree.

P.S. this subject has been touched upon and discussed by many members in the dedicated EM launcher thread, please take a look. I don't want to repeat it in pages to a CV thread.
 

FairAndUnbiased

Captain
Registered Member
If you did not make such confusion, that is great, it was only my feeling.

Please keep focus on the catapult subject. My point was that there is equal issue of load balancing/matching work in both EMALS and Steam Catapult system but only manifested in different forms. To which you disagree.
Steam catapult doesn't need instantaneous electrical supply. The energy used to boil the water can be supplied constantly. So there is no question of how to store electricity.

EMALS needs instantaneous electricity supply. The peak power demand for EMALS is much higher than baseline. I don't know exactly how much but let's say it 2x base load, close to the quoted 30% peak for cruising power.

In civilian power engineering, such a large increase in demand is met through increasing generation.

In a carrier, this is supposed to be met with storage, maybe in a flywheel.

But noting that there has never been grid scale electricity storage equal to 2x base demand in civilian grids, I am not sure how reasonable it is to have this demand on a carrier grid.
 

taxiya

Brigadier
Registered Member
Steam catapult doesn't need instantaneous electrical supply. The energy used to boil the water can be supplied constantly. So there is no question of how to store electricity.

EMALS needs instantaneous electricity supply. The peak power demand for EMALS is much higher than baseline. I don't know exactly how much but let's say it 2x base load, close to the quoted 30% peak for cruising power.

In civilian power engineering, such a large increase in demand is met through increasing generation.

In a carrier, this is supposed to be met with storage, maybe in a flywheel.

But noting that there has never been grid scale electricity storage equal to 2x base demand in civilian grids, I am not sure how reasonable it is to have this demand on a carrier grid.
I am surprised why you kept saying the highlighted. Of course no.

The steam is supplied constantly, but replenishing the reservoir for a launch takes longer time (in minutes) than releasing (in seconds). The amount of steam for the launch has the constant energy, but due to the difference in time in replenishing and releasing, the power is different as power = energy / time. This is exactly the same as flywheel charging and releasing. You can call it instantaneous power vs. constant power. The difference exists in both systems.

Note, it is not instantaneous electrical supply, but instantaneous power be it in electrical form or heat form in steam. By your repeating this expression, I am pretty sure that you mixed up energy/power with its medium (steam and electricity) now.

Now I will do other members the favour to stop the subject now.
 
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FairAndUnbiased

Captain
Registered Member
I am surprised why you kept saying the highlighted. Of course no.

The steam is supplied constantly, but replenishing the reservoir for a launch takes longer time (in minutes) than releasing (in seconds). The amount of steam for the launch has the constant energy, but due to the difference in time in replenishing and releasing, the power is different as power = energy / time. This is exactly the same as flywheel charging and releasing. You can call it instantaneous power vs. constant power. The difference exists in both systems.

Note, it is not instantaneous electrical supply, but instantaneous power be it in electrical form or heat form in steam. By your repeating this expression, I am pretty sure that you mixed up energy/power with its medium (steam and electricity) now.

Now I will do other members the favour to stop the subject now.
Ok then that is the critical part I misunderstood.

I had thought that the steam was generated continuously and supplied to a pressurized reservoir.

I did not realize it was being generated shortly before use.
 

taxiya

Brigadier
Registered Member
Ok then that is the critical part I misunderstood.
There is still something I need to clarify.

I had thought that the steam was generated continuously and supplied to a pressurized reservoir.
The seam is generated continuously by the boiler. However, the amount of steam in the few seconds of launch far exceeds the boiler can continuously supply during the same time frame (in seconds) even if cutting off the supply to the propellers.

So the reservoir is needed not only to ready a launch in standby for long time, but most importantly to accumulate enough steam for the launch.

I did not realize it was being generated shortly before use.

It is generated continuously, but accumulated for enough amount during a long time. That accumulation process is the same as flywheel charging.

I hope everything is clear by now. :)
 

Aurora6666

Just Hatched
Registered Member
Hybrid (SMR + something) is his personal suggestion, not what is known or said about CV-18.

HEV is a "I have to get into EV but I have no better choice". People are not buying it, but waiting for Full EV to drop price. HEV adds dead weight in both low and high speed, a waste of money. At low speed, the ICE is dead weight, in high speed the battery and Electric motors are dead weights. I wouldn't take that trouble if I were PLAN.


I don't know where you heard it, I only heard this 福建舰采用舰船综合电力系统 from Xi Yazhou's video about CV-18. Here is the link
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at 3:10, he said 综合电站动力系统
View attachment 91402


However, at 6:39 he said CV-18 utilizes the similar design of integrated electric power station as Ford class.
View attachment 91403
at 6:42 he said the design take part of power to generate electricity (for EM launcher).
View attachment 91404

We know that Ford class is NOT IEPS, its propellers are driven mechanically by the steam turbines. Diverting part of the power to generate electricity means that the other part of power is not electricity but steam/mechanical power.

It was his mistake to put up 综合电站动力系统 (Integrated Electrical Power Station Propulsion System, ie IEPS) in his slide. It should have been 综合电站系统 (Integrated Electrical Power Station System).

I see many people here has taken that error as fact to call CV-18 being IEPS in this forum, in including another post I have responded to. I hope this will clarify things.
Not sure if Xi Yazhou provided concrete information.

Several different resources express otherwise.

i.e. a news from 2019:

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Meanwhile from another resource:
 

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taxiya

Brigadier
Registered Member
Not sure if Xi Yazhou provided concrete information.
I don't know if you are asserting that "CV-18 utilize IEPS" or you are refuting it. Here is my assessment regardless.
Several different resources express otherwise.

i.e. a news from 2019:

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Firstly, the sina news. It acknowledged that 055 is not using IEPS.
我国055型万吨级导弹驱逐舰虽然也曾传闻采用了全电推进技术,但现在已被证实是误传

Then the article stated that CCTV said MVDC IEPS by Ma's team is actually used in real life, WITHOUT quoting when and where CCTV stated so in which channel. There is no source.
而肖飞教授所在的马伟明院士团队研制成功的舰船中压直流综合电力系统属于第二代,央视和军报对其的评价是:在全球首次研制成功并实现实际应用

Then again the article said 054A utilized "Regional DC Power Distribution System".
根据公开报道,上文中提到的应用直流区域变配电分系统的国产新型护卫舰应为054A型护卫舰。
I have found the text of PLA daily report
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which said
他研制的直流区域变配电分系统,成功应用于我国新型护卫舰和岛礁风光储一体式发电站建设
The PLA daily said new type of frigate without saying 054A or B.

Note, 直流区域变配电分系统/Regional DC Power Distribution System is NOT IEPS. Zumwalt also have a DC distribution system for the hotel load, but it is not MVDC IEPS.

It is clear that the author mistaken MVDC IEPS with Regional DC Power Distribution System. They are based on same technology but not the same thing.

It is also clear that CCTV made the same mistake that is repeated by the sina author in a "shit in shit out".
Meanwhile from another resource:
This is the general diagram of IEPS, it can be AC or DC. Zumwalt and Type 45 could be presented by the same diagram.

Xi Yazhou may have made an mistake, but he still know what he was talking about. This can be seen that he used right terms in the two last screen dumps in post #294

However the author of the sina article sees everything MVDC IEPS whenever Ma's team is involved. He/She apparently knows nothing about IEPS.

Finally, since 055 is confirmed not using IEPS, it is 99.999% safe to say that CV-18 is not using IEPS. It is 100% certain that there is no evidence to prove otherwise so far.
 
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Lethe

Senior Member
On the subject of nuclear power and the costs/schedule implications thereof, I found an interesting 1994 document:

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The engineering effort is equivalent to that required to build the nuclear propulsion plants for about 10 Los Angeles class submarines or that required to build the nuclear propulsion plants for about four Virginia class cruisers. "The leadtime [sic] for procurement of these large nuclear propulsion plant components is more than 2 years longer than the next most limiting hardware," the Naval Nuclear Propulsion Program told Congress in 1972 as two Nimitz class carriers were under construction. In fact, "It was known from the start that delivery of these components would control the construction scheduled for the Nimitz class carriers." (pp. 43-44)
[....]
In the past, construction of nuclear-powered carriers has taken an average of 7.2 years between funding and commissioning, compared with only 4.2 years for conventional carriers. (p. 45)

The document goes into many other facets of nuclear and conventional carrier operations and is worth reading, particularly in relation to the lower historical availability of nuclear vs. conventional carriers and the real-world failure to realise other alleged advantages such as reduced replenishment requirements. However, it is the short-term opportunity costs (i.e. funds and schedule) that are most relevant to my critique of the nuclear path for China at this juncture.
 
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