Viewing 7 posts - 76 through 82 (of 82 total)
  • Author
    Posts
  • #9966
    AaronB
    Participant

    Looks good. I would add high-voltage lines coming out of one side, and maybe a barbed-wire fence around it. Maybe put an EV charging station in front of the truck. The reactor, capacitors, cooling equipment and transformers could be in the basement level to help with the shielding, and the sauna for the occasional maintenance worker could be on the main level as you walk in.

    #9969
    zapkitty
    Participant

    AaronB wrote: Looks good. I would add high-voltage lines coming out of one side,

    Well, it’s intended more as a concept to hang numbers off of rather than an actual model to add details to 🙂

    And if it’s supposed to be part of a distributed grid, a node, would it need particularly high voltage to supply its allotment of 2000 or so homes?

    Perhaps there would be dedicated “export” nodes scattered along the grid to either provide peak power or, when local demand is low, to package their own output along with excess power from the grid for high-voltage export?

    AaronB wrote: and maybe a barbed-wire fence around it.

    Well, in America at least, chain link with barb wire tops. Given crime rates and the voltage for even district-wide distribution, yeah. They’re even having to secure wind turbines behind such fences.

    Still want to keep folks 12 meters away from the housing in case of that impossible core breach and we want a meter of grass between the fence and the sidewalk so the land plot goes to 26 meters a side…

    Y’know, in some of those socialist countries they disguise substations of similar value and power as houses for aesthetic purposes. Looks just like any other home on the block except for the warning sign on the front door.

    AaronB wrote: Maybe put an EV charging station in front of the truck.

    I’ll leave that to the visually-abled types 🙂

    AaronB wrote: The reactor, capacitors, cooling equipment and transformers could be in the basement level to help with the shielding,

    What help with the radiation shielding? All the shielding that’s needed is included with the standard 3 meter x 2 meter x 2 meter FF box in the housing… I’m still using the standard box unless and until the team changes the parameters.

    And anyways a subsurface setup would make accessing equipment for installation, maintenance or replacement a bit more difficult, no? … of course one of those socialist countries might do something like that… 🙂

    Anyways, the equipment housing in the generic design has no basement… instead it’s raised 10 cm off the ground on a platform that can serve as a fire ant barrier or, depending on local conditions, it can house drainage passages (with optional high speed pumps for post-tsunami duty) or even apartments for mongooses (useful for places where you might find cobras coiled amongst the ‘caps).

    Of course anything I could place in the housing now besides the FF unit would just be busywork… but attached find the interior w/ some random boxes along the walls and some extra tanks of switch gas just for Derek 🙂

    AaronB wrote: and the sauna for the occasional maintenance worker could be on the main level as you walk in.

    Well, of course if you’re going to drag water cooling into it then you could make the blasted thing invisible 🙂

    (scene: a stream wends through a park… the only odd note is the large submarine-type snorkel poking up out of the stream…)

    …. anyways, here’s some intermediate figures…

    previousIy I’d said:

    Practical examples show that conduction and convection from similar plant heat outputs aren’t a problem for their surroundings with suitable exhaust stacks but still want to run dispersion models for insurance.

    hmmm…. what’s this? online tools…. how cheap and tawdry of me would that be?

    …lessee what they give us 🙂

    It seems that with an exhaust temp of 250 C the governing conditions for plume rise and dispersion are superadiabatic by definition. Of course by the time the plume gets high enough for the lapse rate to mean much it’s already become a non-issue for local concerns… but the variety of calculation tools online are all aimed at finding the locations and amounts of pollutants entrained in the plume, not the plume temp itself per se.

    But the tools should serve for a rough cut… here the one I’ll use for now:

    http://www.ajdesigner.com/phpdispersion/effective_stack_height_equation_superadiabatic.php

    With the given stats and a windspeed of 15 m/sec (33.5 mph – bad weather!) the plume rise will be 31 meters for a total of 42 m height (on a calm day that goes up to 465 m)…

    … given the poor thermal conductive properties of air and the convective tendency to rise it seems that this whole heat thing just became a non-issue… except for tall buildings within a few hundred meters downwind…

    Still need to model it all out properly though.

    Attached files

    #9974
    Tulse
    Participant

    Y’know, in some of those socialist countries they disguise substations of similar value and power as houses for aesthetic purposes.

    That’s certainly true where I live, in Soviet Canuckistan — Torontograd has many such substations.

    I’m very dubious, however, that a residential plant would be permitted with such a large cooling tower — the height alone would prohibit it from many such locations. However, if the idea is to place small modules all around cities, I wonder if one can’t use the existing water/sewer system as a heat sink. Even if one isn’t going to use the plant for district heating, one might be able to simply run the cooling pipes into the local water infrastructure. Or, alternatively, build such plants at sewage treatment plants, and use the excess heat in the water treatment process.

    #9982
    zapkitty
    Participant

    Tulse wrote:

    Y’know, in some of those socialist countries they disguise substations of similar value and power as houses for aesthetic purposes.

    That’s certainly true where I live, in Soviet Canuckistan — Torontograd has many such substations.

    I thought the Indiana Imperial Senate had renamed that city North Hoosierville after the last time we invaded you?

    Tulse wrote: I’m very dubious, however, that a residential plant would be permitted with such a large cooling tower — the height alone would prohibit it from many such locations.

    One, it’s not what most people think of when they think of an industrial cooling tower… it’s actually just a vent duct over an air-cooled heat exchanger (ACHE). For those unfamiliar, these are akin to a really big car radiator and are extremely common in industry with capacities ranging from a few kilowatts to gigawatt-range installations.

    The only thing that sets this one apart from myriad others is that the coolant in the radiator is helium fresh from a fusion reactor… 🙂

    Second, and perhaps more relevant :), the duct and its height are not needed if you’re willing to pay a bit more for the installation. I was aiming for “universal” and “cheap.” But throw more coolant at the unit and you can even bring down the temp to where a standard off-the-shelf ACHE can lift the 5 MWt… and its exhaust would only be 60 C.

    (Somewhere along this path the cost of expanding the helium loop will overtake the cost of using a water loop and the helium loop will be scaled back to just getting the heat out of the core to where the water can take it away.

    http://www.gearainey.com/opencms/opencms/gem/en/calculators/AFC_Calculator.html

    Attached find crude representations of just such an off-the-shelf unit engulfing the building housing the FF 🙂

    Tulse wrote: However, if the idea is to place small modules all around cities, I wonder if one can’t use the existing water/sewer system as a heat sink.

    Speaking from my experience at the Indianapolis Department of Public Works, it would be very iffy in general and impossible here. In general urban water systems are not designed for the extra energy input even if it is distributed over a large area. And many systems such as ours in downtown Indy are shamefully antiquated… they’d collapse. Literally.

    The problem with water cooling, and thus the increasing dominance of “dry” systems such as ACHE, is that heated water must go somewhere and will get you in a lot of hot water of your own if you’re not very careful.

    Tulse wrote: Even if one isn’t going to use the plant for district heating, one might be able to simply run the cooling pipes into the local water infrastructure.

    Or, alternatively, build such plants at sewage treatment plants, and use the excess heat in the water treatment process.

    For the long term you’d certainly design the infrastructure around the availability of such units.

    That’s for the long run. But currently in the U.S. our infrastructure planning, never strong since the conservative rise to power, has now been overtaken by the teabaggers… who don’t believe government can work and are intent on proving it.

    Thus plug-and-play units are the best way for distributed use, even if air-cooling costs a bit more for units in residential areas.

    And of course FF units installed in existing power and industrial infrastructure can make use of the existing water cooling.

    Attached files

    #9983
    Tulse
    Participant

    I’m curious as to what, if any, regulations there are about waste heat in residential areas. Many houses in northern climes of course have chimneys, but I doubt any fireplace is putting out 5MWt. What effect would a large 60 C air stream have on a local clime? I don’t have a good sense of the relative scale of the heat being dumped — is this comparable to the exhaust of an industrial air conditioner, or something much more substantial?

    #9986
    zapkitty
    Participant

    Tulse wrote: I’m curious as to what, if any, regulations there are about waste heat in residential areas.

    Apparently very few regulations that don’t involve something being burned.

    Tulse wrote: Many houses in northern climes of course have chimneys, but I doubt any fireplace is putting out 5MWt.

    This is off the cuff but about 250 large homes with their furnaces going…

    Tulse wrote: What effect would a large 60 C air stream have on a local clime?

    Even in a stiff breeze it would rise ~20-30 meters and would disperse laterally even further before impacting the neighborhood.

    Tulse wrote: I don’t have a good sense of the relative scale of the heat being dumped — is this comparable to the exhaust of an industrial air conditioner, or something much more substantial?

    … an office buildings total heat output or a car being set on fire… 🙂

    #9987
    zapkitty
    Participant

    … and if the 60 C is somehow just unbearable you can lower it to 30 C 😉

    Attached files

Viewing 7 posts - 76 through 82 (of 82 total)
  • You must be logged in to reply to this topic.