Heat exchanger margin
Thread Content
As shown in the figure, why has the cooling water volume decreased while the heat transfer surplus has increased?
The heat load (Duty) under the latter operating condition is about 10% lower than that under the preceding condition, and the required heat transfer area also decreases accordingly.
Theoretically, the heat released and the heat removed are equal. To remove the heat released, 229 kg/s of cooling water at 32–42 degrees is required. The amount of water used in the second case is less; with such a small amount of water, it’s not enough to remove the theoretical amount of heat. Is this reasonable?
Theoretically, the heat released and the heat removed are equal. To remove the heat released, 229 kg/s of cooling water at 32–42 degrees is required. The amount of water used in the second case is less; with such a small amount of water, it’s not enough to remove the theoretical amount of heat. Is this reasonable?
There are too many specified conditions, which makes it easy to make calculation errors; for the hot side, the flow rate and inlet/outlet temperatures need to be specified, while for the cold side only the inlet/outlet temperatures are required, as the software will calculate the water volume itself.
Mm-hmm, that’s indeed the case. The amount of water needs to be calculated by oneself, and the heat released and absorbed by cold and hot substances must be balanced. Q=C M △T
. . Your result should come with a warning; the warning probably states something like a lack of heat conservation on the hot side and the cold side. In your case, it’s clear that the calculation uses the heat load of the cooling water as the basis for the overall heat transfer calculation. The calculation is incorrect.
Right, right – it indicates hot and cold loads, one for each, and actually it’s verified using another load; it seems that the intermediate value of the two is taken