Using high conductivity water / un demineralized water as cooling water & effect on heat exchang
Using high conductivity water / un demineralized water as cooling water & effect on heat exchang
(OP)
Dear all,
in my plant, we used raw water or undemineralized water as cooling water. Is that giving a bad effect on the heat exchanger tube, for example higher rate of corrosion or fouling? The treatment that is used for the cooling water is only NaClO injection.
Because I know most of cooling water especially in coal fired power plant use demineralized water as cooling water.
Thank you.





RE: Using high conductivity water / un demineralized water as cooling water & effect on heat exchang
If it's a closed loop system like a cooling tower, then it's always necessary to actively monitor the water chemistry and to treat it with additives. If it's once-through water, then the need for treatment entirely depends on the chemical analysis of the source water.
Regardless of whether it's once-through water or a closed loop system, you need to prevent the temperature rise from getting too high (above ~120F). Otherwise calcium carbonate will precipitate out of solution and build up on the internal surfaces. Exchangers need to be designed to ensure that the cooling side outlet temperature doesn't get too hot and necessitate frequent outages for cleaning.
RE: Using high conductivity water / un demineralized water as cooling water & effect on heat exchang
David Simpson, PE
MuleShoe Engineering
In questions of science, the authority of a thousand is not worth the humble reasoning of a single individual. Galileo Galilei, Italian Physicist
RE: Using high conductivity water / un demineralized water as cooling water & effect on heat exchang
The quality of the raw water determines the cycles of concentration for the cooling tower. If the raw water was of very poor quality (Sea Water for example), you would use the raw water once through.
Generally, you would want to have a water quality that will allow 6-9 cycles of concentration for economical operation of the cooling tower. So the contaminants of concern such as hardness would concentrate 6-9 times, but still be below the concentrations that will not have a detrimental effect on the cooling tower operations and condenser operations.
RE: Using high conductivity water / un demineralized water as cooling water & effect on heat exchang
Regards
Ashtree
"Any water can be made potable if you filter it through enough money"