How to calculate the heat occupied by the deaerator?
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Part of the heat coming out of the waste heat boiler is sent to the deaerator; how is this amount of heat calculated?
It generally accounts for 3% of the rated evaporation rate.
This post was last edited by dongjiang1001 on 2011-11-9 at 18:40. Heat Q = steam volume x steam enthalpy (the enthalpy corresponding to the temperature and pressure of deaerated steam).
This post was last edited by dongjiang1001 on 2011-11-9 at 18:40. What 729 said is pretty much correct, but not entirely accurate. It should be: Heat Q = amount of steam x (enthalpy of steam – enthalpy of steam when it becomes saturated water). The heat required is equal to the enthalpy difference resulting from heating deoxygenated water to a saturated state; a small margin (for heat loss) is sufficient.
This post was last edited by dongjiang1001 on 2011-11-9 at 18:41. Generally, according to empirical formulas, to heat water to the saturated temperature of 104 degrees at the deaerator, the amount of steam required is 15% of the boiler’s rated steam output; that is, for a boiler with a rated evaporation capacity of 10 tons, the steam input to the deaerator should be 1.5 tons. The same principle applies in similar cases.
If what the comrade on the 5th floor said is correct, then this will be very practical.
I think what was said on the 5th floor is a bit vague; the amount of steam required has to be calculated. Personal opinion: Assuming that the heat source steam required for deoxygenation is a t/h, and the enthalpy difference between this heat source steam and the saturated water it becomes is h, then the energy provided by the heat source is: a*h. The water replenishment amounts are as follows: steam turned into saturated water at a rate of a t/h, condensate at a rate of c t/h (with the temperature of the condensate being t1), and fresh feedwater at a rate of d t/h (with the temperature of the fresh feedwater being t2). The total amount of water used in the deaerator is therefore e = a + c + d t/h. The temperature of the mixture of condensate and fresh feedwater is t3: t3 = (c*t1 + d*t2) / (c + d). The enthalpy value of water at this temperature is h1; the enthalpy value of saturated water at the outlet of the deaerator is h2. Thus, the amount of steam required to heat the feedwater is: h*a = (c + d)*(h2 – h1). The value of a represents the steam consumption, while the heat quantity required is given by Q = (c + d)*(h2 – h1)