Cooling towers Vs Riverwater cooling

[Cammy]

Hi guys, looking for a little help with my uni dissertation. I am looking into the CO2 & cost savings (long term) of using river water to cool a condenser as opposed to using a cooling tower. One question that has been thrown up from looking at other works is, why is there an increase in CoP when using river water? Is it as simple as the ambient temperature of the water is less than the wet bulb of air?

cheers for any help clearing this up,.

[The Viking]

If fresh water cooling is an option, then throw HSE regulations at the project and you will see that a cooling tower can't compete.
The costs and environmental impact from water-treatment of a cooling tower will be astronomical in comparison to cleaning the strainers on the river water loop.

Another option would be a closed loop (collector) submerged in the river.

The CoP thing I think that you got sussed, it is also another heat exchange to take place in the cooling tower and the water going through the tower will not reach WBT.

[Cammy]

Thanks mate, glad i got that part sorted!

DO you happen to know if there are any rule of thumb figures associated with the cost of dosing for cooling towers per Litre of water or something along those lines?

[The Viking]

Unfortunately it will vary depending on a lot of factors, one of which is what council it is located in.
Your best option would be to contact a local water treatment company and ask them, another option to find someone that operates a cooling tower locally to you.

A while back, we quoted for maintenance for a site with a cooling tower and IIRC, the annual cost for the water treatment were almost £10k.

[Cammy]

Jesus! that's pretty expensive.

I have one more question, sorrythis could go on forever, if i am saying assume a CoP of 4 for a cooling tower cooled system, is it reasonable to assume that the CoP for water source cooling could be 7 (or 8)?

Also, which calculation can i use to show this, cop=heat rejected/power input? the problem is i dont have any manufacturers data for this project so it's all a bit up in the air.

thanks for any info

[shams]

Thanks a lot dear.

[Lc_shi]

Jesus! that's pretty expensive.

I have one more question, sorrythis could go on forever, if i am saying assume a CoP of 4 for a cooling tower cooled system, is it reasonable to assume that the CoP for water source cooling could be 7 (or 8)?

Also, which calculation can i use to show this, cop=heat rejected/power input? the problem is i dont have any manufacturers data for this project so it's all a bit up in the air.

thanks for any info

Hi Cammy
You're right to assume the COP of the cooling tower is around 4 ,but COP of the water source is 7 or above is not reasonable. Both the cooling system only affect the condensing temperature, the river water temp is lower than ambient air and the average water temp of the cooling season decide the chiller condensing temperature. If the cop up to 7 or above ,the theoretic condensing temp should be lower than 25C, it's not reasonable.

Cooling tower and river water all need water treatment. River water cooling should be better use close-loop heat exchanger.


regards
LC

[Don Davis]

What about the fish? We have a local power plant using river water to condense steam but environmental regulations force the operator to run the water through cooling towers before putting the water back into the River. In the end, he is only able to increase river temp by 2-3 degreesF.