Determining Mass Flux Of Feed Water In A PF Boiler?

sorry for calling ASAP wrong time.. by the way thanks for your response

Nice paper, I sure hope our budding designer can get past equation (8), but I will give him credit for choosing the right screen-name.

If you size the pump for 800 kg/s, it will be able to keep up with occasional higher-than-average steam consumption. In the long haul, the pump will run half the time. If your stem consumption is steady, a pump sized for 1.5 x or even 1.25 x of steam consumption should suffice.

I could be wrong, but I doubt it...any PF coal unit will be found to be also a once-through Universal Pressure or supercritical steam generating unit with no steam drum.

In such systems, steam generation depends upon the boiler feedwater pump operating on a 100% continuous (and 100% reliable) basis. Otherwise, the unit generating power from the steam will be unstable, and trip repeatedly.

I will say there is a discussion of the conservation of momentum in the waterwall tubing of PF boilers in the paper that Lyn linked to. That paper is essentially right, without stating one further boundary value - namely the precise flow rate at which flux is wanted. My understanding of water flux (and at some point steam flux which has to match the water flux at some earlier point in the tube) is that the flux is simply the mass flow rate in kg/s divided by the fluid density at the point (from the temperature at that point, and values in the steam tables to match P, T, although the specific volume can also be utilized, also), the result is fluid flow rate in m³/s at that point in the system. To obtain flow velocity, one only has to divide volume flow rate by cross-sectional area, to arrive at m/s units. To obtain flux, kg/m²-s, one divides the mass flow rate by the cross-sectional area. It is not rocket science, it just depends on having some reliable data from the system at hand, either design or actual operating data will suffice in most instances, unless sumting mayorly wong.

ASAP? New year's eve 2023 is possible, Mildred.

GA because what you say is correct.

What has me stumped is how you were even able to interpret that this is what the OP wanted to know.

Regards

WAL

Use the concept of he Mass Balance: Input = Output + Accumulation. Sum all he flows into the boiler. There is no accumulation, as the level remains constant, so this total must equal the sum of the flows out.

"Robert is your mother's brother." - Anon.

Since when in Universal Pressure (once through), or in supercritical boiler (also once through) is there any such thing as a water level? There are only tubes, no vessels. No steam is contained within any large bulk volume vessel in such a case, as all the fluid being heated is in the evaporator tubes, superheater tubes, or in the re-heater tubes. We did not make this far by accident. This is a divine appointment.

Does this thing about Robert being your mother's brother have anything to do with the "uncle-daddy" story in Kansas?

Whatever.