Jed calculations is an order of estimate but actually on the conservative side:
1 MJ/s = 239,000 calories/s. 80°C - 20°C = 60°C. 239,000 calories / 60°C = 3,983 g/s = 239 L/min (61 gallons), which far exceeds the capacity of the entire building. It would take time to heat up the water to 80 degrees, then it will take time to exchange heat with the 20 degree water and so on, this will reduce the efficiency of the exchange. The right solution is probably a differential equation and I bet you get a even higher value of water flow needed. Unless you had enormous pools of water involved (cold and hot) you cannot think of this as a thermo-equilibrium situation. For an order of magnitude estimate I prefer to think that you will need a ton of water with 1 degree difference coming in an out of the building every second to deal with 1 MW poer (similar considerations about time needed to heat up and cool down the water applies but it is easier to think about 1 m^3 of water with a slight higher temperature involved to represent a solution closer to the non-equilibrium realistic one). In any case even if one adopted the conservative Jed estimate one can see easily the heat exchange idea is nonsense. On Mon, Aug 15, 2016 at 10:17 AM, Jed Rothwell <jedrothw...@gmail.com> wrote: > Peter Gluck <peter.gl...@gmail.com> wrote: > > >> Both, Jed and goiovanni are trying to show tht they are not understanding >> what I have told about the energy: the cut the Gordian solution of >> consuming the energy is to pass the steam pipe through a system of heat >> exchangers where it heats water. that is discraded to the drain channel as >> water at 40-50 C. being, (exactly as this discussion diluted to >> insignificance) >> > > The heat exchangers would produce waste heat, which would be readily > apparent. It would heat up the entire warehouse. > > More to the point, the heat exchangers would not serve any purpose. They > do not make heat vanish, they merely transfer it. The total amount of water > you need is the same with or without the exchangers (except for the waste > heat lost from the exhangers). So, you might as well leave out the > exchangers and use the water to cool the main loop. This, however, is > impossible. A normal commercial building in Florida has a 2" water supply > pipe, which is not large enough for the flow of water you need to keep the > temperature below the legal maximum of 80°C, with 1 MW of heat. > > 1 MJ/s = 239,000 calories/s. 80°C - 20°C = 60°C. 239,000 calories / 60°C = > 3,983 g/s = 239 L/min (61 gallons), which far exceeds the capacity of the > entire building. > > Your plan makes no sense. Evidently you do not understand the conservation > of energy or thermodynamics. > > - Jed > >
