ventilatiom of boilers water feed pumps!!!
ventilatiom of boilers water feed pumps!!!
(OP)
hi
]i ve asked to ventilate boilers water feed pumps there are 3 pumps each 4MW I/POWER any ideas or experience at this issue wil be good
thanx for advance
]i ve asked to ventilate boilers water feed pumps there are 3 pumps each 4MW I/POWER any ideas or experience at this issue wil be good
thanx for advance





RE: ventilatiom of boilers water feed pumps!!!
RE: ventilatiom of boilers water feed pumps!!!
RE: ventilatiom of boilers water feed pumps!!!
I am with you on this.I beleive this forum is for exchange of ideas and experience among serious professionals in the industry.It is definetly not the place for a bunch of lazy guys who want the easy way out!
This has been a trend of late as you rightly noted.The only way to correct things is to ignore such questions.That way we can ensure that they do not stay in the main page for long!
RE: ventilatiom of boilers water feed pumps!!!
the boiler's pump room is for power plant and have been
ventilated by 3-fresh fans it's cap.1150 m3/hr the pumps are 3 MW each the f.fans doesnt work the designer put them at a south wall not far from the boiler all i asked for is a hand of help what should i do ?put a specific coling unit to overcome icrease of heat? put more fresh and exhaust fans ??
sorry for the disturbance and i ll search on the old forums at this site
RE: ventilatiom of boilers water feed pumps!!!
You have problem wih heat drawn in by fans during hot weather? The reason for ventilation appears to be pump motors heat rejection?
RE: ventilatiom of boilers water feed pumps!!!
transfered due to hot weather ?
RE: ventilatiom of boilers water feed pumps!!!
But in summer, these fans should be switched off, probably by temperature controller. Air changes should be reduced to absolute allowable minimum during such weather (this room is not permanently occupied, so it can be rather low figure, compared to work of 3 big fans). If temperature rise is too high, room AHU should be added, dimensioned according to that minimal air quantity, not according to big fans capacity!
RE: ventilatiom of boilers water feed pumps!!!
What is the maximum temperature that the room can be?
What is the temperature of the available air that will be used for ventilation?
Required ventilation rate is then pretty simple to calculate.
RE: ventilatiom of boilers water feed pumps!!!
Do all 3 pumps run at the same time?
Are the pump motors high efficiency?
Are the motors open drip-proof?
How are the motors controlled, by variable speed drives?
Are the cooling/ventilation and combustion air loads combined for the fans?
Do the boilers operate year 'round and what is their function.
Hard to solve the problem if the problem is not clearly stated.....
RE: ventilatiom of boilers water feed pumps!!!
RE: ventilatiom of boilers water feed pumps!!!
I agree, the OP's question is poorly asked, and has the characteristic of "please do my job for me because I have no understanding of fundamentals".
RE: ventilatiom of boilers water feed pumps!!!
* yes the three pumps working at the same times and there is another one stand by
**the motor efficiency are high
*** i dont know what is the drip-off motor is it a motor kind?
**** boiler are operating year around and it is useda at producing electricity.
sorry i dont know what do u mean by" Are the cooling/ventilation and combustion air loads combined for the fans?"
RE: ventilatiom of boilers water feed pumps!!!
The poster has stated 3 pumps running at a time.
Size 3mw or 4 mw.
Let's go with 3 times 4 mw. that's 12 mw.
Assume the efficiency at 90%. The heat rejection will be 10% of 12 mw or 1.2 mw.
Or
Assume an efficiency of 85%. The heat rejection will be 15% of 12 mw or 1.8 mw.
If someone in the forum will now suggest a reasonable temperature rise and a corresponding ventilation rate we can give etchyHA a couple of reasonable figures for his fan capacity.
It will be etchyHA's responsibility to determine the actual efficiency of the motors and possibly scale our suggestions to match actual site conditions.
When I am frustrated by poor information, I try to remember that this is an international forum and english may not be the posters first language.
I also try to remember that I follow the forums to both gain new information and to offer help to others.
respectfully
RE: ventilatiom of boilers water feed pumps!!!
A motor of this size very likely has provisions for, or options for forced external cooling.
You don't start a 40 MW motor across the line, so there are probably some sort of drives that have power conversion losses to consider.
RE: ventilatiom of boilers water feed pumps!!!
If you would like to help that would be nice.
If you want to pick nits;
Losses are related to but not proportional to power.
Power is proportional to the cube of pump flow AT CONSTANT PRESSURE. An increase in flow is often a result of decreased back pressure.
Running three out of four pumps of this size on a power boiler, it is safe to assume that the pumps are loaded and sized properly.
Provisions for forced external cooling?? Are you confusing motors with transformers? If a motor is designed for external cooling it will have external cooling, not "provisions for". Other than water cooled motors, ther heat rejection is independent of the cooling method. If a motor is rejecting 0.4 mw of heat it doesn't matter if it's open drip proof, TEFC or whatever. 0.4 mw is still 0.4 mw.
It is not common practice to hang a starter or drive on the wall beside a 4 mw pump. The drives will be in the electrical equipment room.
etchyHA;
If you know the rated efficiency of the motors, please post it.
Also, what is the temperature of the outside air and what is the maximum temperature you would like to limit the inside air to?
respectfully.
RE: ventilatiom of boilers water feed pumps!!!
RE: ventilatiom of boilers water feed pumps!!!
Thank you for your response. It is exactly what I would have hoped for. I hope it is of use to etchyHA.
Respectfully
RE: ventilatiom of boilers water feed pumps!!!
So going as per the standard equation,
Q(BTU/hr) = BHP x 2545/eff. or IHP/2545
If IP is 4MW (i.e 4000000/745 = 5369 HP),
Q = 5369 x 2545 = 13664105 Btu/hr
For a 10F dT, 13664105 = 1.08 x cfm x 10 or flowrate is 1265195 cfm or 2151693 cu.m/hr
For three pumps, it is 6455076 cu.mtr/hr or 3795585 cfm.
That would take a 1000 HP motor (if there is no much duct work)
Personally, I would rather pray God (atheists should excuse me) to send twisters to the boiler pump room 24x7
RE: ventilatiom of boilers water feed pumps!!!
waross
rated eff.=.75
o/T=40C
max. temp at room =30:35 c
RE: ventilatiom of boilers water feed pumps!!!
Typical feedwater pump room arrangements will require some pretty specific geometry for the air introduction and circulation, to the point where many are built double wall and drop ceiling so the wall cavity is one plenum and the interstitial space is another. Some use cooling tower water to prechill incoming air at highest outdoor ambients, depends whether ambient temp profile only rises to within 5% of peak temperature for 10% of total time, or 25% of total time.