sewage source heat pump issue

[Lc_shi]

Many cities use sawage resource heat pump for building air conditioning but there're headache for the heat exchanger fouling issue,esp the biological fouling. Any body know the advanced technology to overcome this issue? thanks in advance!

regards
LC

[mad fridgie]

Scraped surface heat exchanger

[desA]

Scraped surface heat exchanger

Not overly efficient, are these beasts, I'd suspect. Probably lots of maintenance.

There would also be a few alternative technologies to manage this, I'd expect.

There was a technology project a year-or-so back, that centred around heat-pumps that extracted their energy from sewerage. On the MW scale, as I remember - US-based company looking for new technology.

Lc_shi are you perhaps involved in this?

[mad fridgie]

Not overly efficient, are these beasts, I'd suspect. Probably lots of maintenance.

There would also be a few alternative technologies to manage this, I'd expect.

There was a technology project a year-or-so back, that centred around heat-pumps that extracted their energy from sewerage. On the MW scale, as I remember - US-based company looking for new technology.

Lc_shi are you perhaps involved in this?
Not found efficiency to be bad on a per meter of heat transfer surface area, but per space requirement is a different matter. A lot of space require compared to say a PHE of some sort.

Maintence, not as much as you make think, modern nylon blades last for years, moter and gear box, i supose comes down to original sizing and build quality.

on the negative if a large piece of crud does get stuck then strip down would be required.

the next question should be what is the exact fouling problem, a part from the obvious "a large turd stuck up the pipe" and how this fouling is manafesting itself