Reply To: Competition from the Thorium reactor

[Rematog]

Cooling Load and Cooling tower design.

I’ve been looking into cooling loads needed for a 5MW Focus Fusion Power Block.

My Assumptions:

Net output power is 5000kw
raw ion power is 98% of input power
raw x-ray power is 57% of input power
raw ion power coversion to electrical power eff. = 90%
raw x-ray power conversion to electrical power eff = 80%
Therefore: 0.98(Input) x 90% + 0.57(Input) x 80% = 5000kw + (Input)
so: 1.338(Input) = 5000kw + (Input)
Input = 14,793 Kw

Heat wasted is (100% – coversion eff) x raw power
Heat(Ion Beam) = 0.98(14,793kw) x 10% = 1450 kw
Heat(X-Ray) = 0.57(14793kw) x 20% = 1686 kw
Allowance for heat at electrode 5% of Input power = 14793kw x 5% = 740 kw.
Total Heat rejected 1450kw + 1686kw + 740 kw = 3876 kw = 13.2 MMBtu/hr for 5 MW net output.

Assume heat load linear with scaling reactor block output.

Cooling Tower Design

I’ve just gotten a cost estimate for a cooling tower which would be sufficient to meet the cooling needs for 200 MW of Focus Fusion output, based on my assumptions stated above.

I’d be glad to forward a PDF of the quote, and the URL of the site which provided it.

Bottom line was bare cooling tower materials $434K, FOB Factory. My rough estimate for installed cost is $625K, not including the circulating water pumps and piping, blow down systems and waste water disposal, make-up water supply and treatment and land.

Result summary: a bare Cooling tower will add $3.12/kw to the capital cost. It’s fans will consume 157kw of the Fusion blocks net output. The cooling water system would have a flow rate of 29,000 gpm and the tower would impose a 24′ head on the cooling water system (to be added to piping pressure loss and delta P flange to flange of the Focus Fusion power blocks cooling system heat exchangers). This was based on an assumed hot water temp of 140F and cool water temp of 100F. It was designed for a Louisiana environment.

The Hot temp is an important design/cost factor, as hotter water is easier to cool with a given ambient air temperature and humidity. I ran the cost estimate again with 180F hot water and 1/2 the flow rate (same heat rejected). Capital cost would be roughly 65%, fan Hp 125% (250 vs 200 HP) and cooling water pump head 2′ more (fan HP more as the same heat is rejected at higher temp, so outlet air temp higher, air less dense, more volume to move….)

In both cases I assumed the more expensive fiberglass construction as opposed to cheaper wood. FG lasts longer and requires less maintenance. For a project with a 30 yr design life, FG gets the nod.

If anyone wonders why I’m assuming a water based cooling system, just ask….