XBradTC

By

XBradTC

·

Shanghai shipyard 'to build second Chinese designed aircraft carrier' | South China Morning Post

China will soon start building its second locally designed aircraft carrier in Shanghai, according to a Canadian report. Kanwa Asian Defence, an English-language monthly defence review produced in Toronto, said Shanghai’s Jiangnan Shipyard was preparing to start work on the carrier. When completed, the carrier and another under construction in Dalian will give the PLA…

China will soon start building its second locally designed aircraft carrier in Shanghai, according to a Canadian report.

Kanwa Asian Defence, an English-language monthly defence review produced in Toronto, said Shanghai’s Jiangnan Shipyard was preparing to start work on the carrier.

When completed, the carrier and another under construction in Dalian will give the PLA Navy two fully functioning, battle-ready aircraft carriers.

The recently completed Liaoning, the refitted former Soviet carrier Varyag, is classed as a training platform, not a full combat vessel, by the navy, since it went into service in September 2012.

Counter to many expectations, the new carrier about to be built at the Jiangnan Shipyard will use conventional, not nuclear power.

via Shanghai shipyard ‘to build second Chinese designed aircraft carrier’ | South China Morning Post.

This is the second new-build, in addition to the Liaoning. It will be interesting to see what the configuration is. And the choice of conventional power isn’t terribly  surprising. Nuclear power of the kind needed for an aircraft carrier is a tough nut to crack. You can build a 30,000 horsepower nuke for a sub fairly easily. The quarter million horsepower for a carrier is somewhat harder.

Tags:

  1. Quartermaster

    We tried putting a number of smaller nukes in Enterprise, and then backed off building others because of the trouble of fueling the thing. I remember the fight over building JFK as an oil burner. After Nimitz was built, it was obvious the Navy was right in taking the path they took on CV nukes.

    Like

  2. Jeff Gauch

    There’s also the pressure vessels. Each PWR takes several large tanks capable of withstanding extremely high pressures. They’re a major reason a CVN takes a decade to build. It’s possible that the Chinese would rather have 4 or 5 SSN’S rather than 2 CVN’s they won’t be able to use properly for years.

    Like

  3. xbradtc

    And I’m guessing you can’t use a BWR at sea?

    Like

  4. Jeff Gauch

    Certainly not on a submarine, you’d end up contaminating the air. On the other hand, this is China we’re talking about. I think there are other issues around putting essentially all of your engineroom inside the shielded volume, and I think PWR give you higher power densities, but I’d have to think on that.

    Like

  5. Quartermaster

    I think you could, but you can’t get away from high pressure. The efficiency of the Carnot Cycle is directly dependent on the temperature difference between the steam generated by the reactor heat exchanger and the cooling water at the condenser. High temp means high pressure.

    Like

  6. Jeff Gauch

    But the only temperatures that count are the saturation temp at the inlet to the turbine and the saturation temp at the exhaust. Everything else is energy lost to the environment.

    The secondary side of a PWR operates at a much lower pressure than the primary. It’s not hard to build a BWR that matches a PWR’s Carnot efficiency. Indeed, since you’ve cut out an entire heat transfer, a loop of water bleeding heat to the environment, and a pressurized, plus the fact that nucleate boiling is much more efficient at transferring heat, BWR’s have much higher total efficient cries, which is why they’re still being built.

    Like

  7. Quartermaster

    I had an evil thought about asking how you can have a saturation temp at the turbine inlet when the steam isn’t saturated, but you and I are the only ones that would probably get the joke. It’s a difference in terminology between operations and thermodynamic theory.

    You are correct, however about the temp diff from inlet to outlet being what counts. That difference is what allows you to determine the energy you were able to extract form the steam.

    Like

Leave a comment