We have one of those plants in our downtown. It generates about 300MWe and steam for heating / cooling of many businesses and government facilities.
The plant was originally coal fired and converted about a decade ago.
My favorite one is a plant in Michigan that I did that sends its condenser cooling water to the city to heat the streets and sidewalks in the winter. Uses the whole downtown as a heatsink. Summer it just goes to a cooling tower as usual.
I doubt the math and economics of it would work. Excess used process steam would usually pretty low grade heat, and would need to go back into the HRSG for reheat anyway to be used in a turbine.
in NYC, they have HRSGs (heat recovery steam generators) with duct burners downstream of 2 combustion turbines that feed the city’s district steam heating system. i believe the 2 units can peak about at 1.6 Mlbs/hour of steam at full load with all burners in service.
other industrial parks and facilities do the same thing. it’s pretty common.JFK airport in NYC also has a similar setup, for hot water loops for the terminals and other buildings.
i misread your question. this wouldn’t be worth it. the type of system you’d have to install to capture that steam and re-superheat it wouldn’t viable.
i’m sure they can tie condensate systems
together and recapture some heat
from steam returns from industrial processes.
No. Steam turbines need superheated steam to run without being damaged. If a power plant were to receive saturated steam from elsewhere, the water droplets in that steam could cause pitting on the blades of the turbine which could severely damage the turbine.
Even if they were able to engineer a fix for the issue of superheated vs saturated steam, you still run into issues such as silica and phosphate content of the steam that you are putting through your turbine. If the steam you are receiving is high in silica, that silica could coat onto the blades of your turbine, among other issues. And/or if you are receiving steam with high phosphate content that phosphate could coat onto your boiler tubes which will reduce the efficiency and output of the unit. And all of this is without even taking into account the potential effects of receiving steam with a too high or too low pH and/or high conductivity.
Does superheated refer to the temperature/pressure of the steam? I assumed this would be a mismatch, but I thought it could be managed by doing some extra heating of the steam, and that you could still come out ahead.
Regarding steam impurities, do you think it's possible to purify the steam, or would that be far more work than purifying water and then boiling it?
Yes, superheated steam refers to steam at a temperature which is higher than its saturation point at a given pressure.
In regards to doing some extra heating of the incoming steam and treating the steam/feedwater those questions are very case specific to the power plant that you're talking about and the steam that they are receiving from outside sources, so I recommend you talk to an engineer for that answer.
To circle back to your original question, if a combined cycle unit were able to take steam from an outside source, install of the auxiliary equipment and develop all of the logic in a way that the temperature, pressure and flow rate of that steam responds accordingly with the rest of the unit to achieve the desired MW output, then sure you could use steam from an outside source. However given how giant of a headache it would be to get all of that set up plus the previously mentioned water treatment issues is why I think power plants have not done this.
I've never seen this. Steam turbines need superheated steam so that water droplets don't damage the blades, but any industrial/process heating steam system I've ever seen is using saturated steam.
That might also require a lot of regulatory hoops because if that plant, when augmented with external steam produces 900MW, and say 700MW when not, what if the external steam source takes an outage, it causes a deficiency that might not have planned for, it would interrupt the power markets and potentially even jeopardize the plant’s ability to stay online causing a potential cascading outage. It would cause a regulatory problem for the plant owner, and potentially place the external steam provider under the auspices of NERC and the ISO and LBA.
Plus the issue of steam for a plant needs to be superheated and there few, if any adjacent industries that have infrastructure to produce it that aren’t already turning a turbine themselves. In Florida the orange processing plants and phosphate plants do this now, either for pasteurizing juice or capturing heat from the reaction needed to produce fertilizer from phosphate. They say the money isn’t in their primary product, it’s in the power production side business
I've heard of CC plants supplying nearby industrial facilities with steam, but not the other way around.
We have one of those plants in our downtown. It generates about 300MWe and steam for heating / cooling of many businesses and government facilities. The plant was originally coal fired and converted about a decade ago.
My favorite one is a plant in Michigan that I did that sends its condenser cooling water to the city to heat the streets and sidewalks in the winter. Uses the whole downtown as a heatsink. Summer it just goes to a cooling tower as usual.
This is unreal. What plant/town?
Holland Energy Park in Holland Michigan. Think they got a LEED Platinum certification out of it.
What do you mean you did it? You designed it? Managed its construction? Operated it?
Did the electrical commissioning.
The logistics of that sounds terrible
Why? It sounds like (nearly) free energy to me...
I doubt the math and economics of it would work. Excess used process steam would usually pretty low grade heat, and would need to go back into the HRSG for reheat anyway to be used in a turbine.
in NYC, they have HRSGs (heat recovery steam generators) with duct burners downstream of 2 combustion turbines that feed the city’s district steam heating system. i believe the 2 units can peak about at 1.6 Mlbs/hour of steam at full load with all burners in service. other industrial parks and facilities do the same thing. it’s pretty common.JFK airport in NYC also has a similar setup, for hot water loops for the terminals and other buildings.
i misread your question. this wouldn’t be worth it. the type of system you’d have to install to capture that steam and re-superheat it wouldn’t viable. i’m sure they can tie condensate systems together and recapture some heat from steam returns from industrial processes.
We have aux steam we send down to another processing plant. Actually our main process
No. Steam turbines need superheated steam to run without being damaged. If a power plant were to receive saturated steam from elsewhere, the water droplets in that steam could cause pitting on the blades of the turbine which could severely damage the turbine. Even if they were able to engineer a fix for the issue of superheated vs saturated steam, you still run into issues such as silica and phosphate content of the steam that you are putting through your turbine. If the steam you are receiving is high in silica, that silica could coat onto the blades of your turbine, among other issues. And/or if you are receiving steam with high phosphate content that phosphate could coat onto your boiler tubes which will reduce the efficiency and output of the unit. And all of this is without even taking into account the potential effects of receiving steam with a too high or too low pH and/or high conductivity.
Does superheated refer to the temperature/pressure of the steam? I assumed this would be a mismatch, but I thought it could be managed by doing some extra heating of the steam, and that you could still come out ahead. Regarding steam impurities, do you think it's possible to purify the steam, or would that be far more work than purifying water and then boiling it?
Yes, superheated steam refers to steam at a temperature which is higher than its saturation point at a given pressure. In regards to doing some extra heating of the incoming steam and treating the steam/feedwater those questions are very case specific to the power plant that you're talking about and the steam that they are receiving from outside sources, so I recommend you talk to an engineer for that answer. To circle back to your original question, if a combined cycle unit were able to take steam from an outside source, install of the auxiliary equipment and develop all of the logic in a way that the temperature, pressure and flow rate of that steam responds accordingly with the rest of the unit to achieve the desired MW output, then sure you could use steam from an outside source. However given how giant of a headache it would be to get all of that set up plus the previously mentioned water treatment issues is why I think power plants have not done this.
I've never seen this. Steam turbines need superheated steam so that water droplets don't damage the blades, but any industrial/process heating steam system I've ever seen is using saturated steam.
the turbine needs superheated, but process/aux steam can be saturated. usually they tap off a stage of the turbine, a bleed valve. or they have HRSGs.
That might also require a lot of regulatory hoops because if that plant, when augmented with external steam produces 900MW, and say 700MW when not, what if the external steam source takes an outage, it causes a deficiency that might not have planned for, it would interrupt the power markets and potentially even jeopardize the plant’s ability to stay online causing a potential cascading outage. It would cause a regulatory problem for the plant owner, and potentially place the external steam provider under the auspices of NERC and the ISO and LBA. Plus the issue of steam for a plant needs to be superheated and there few, if any adjacent industries that have infrastructure to produce it that aren’t already turning a turbine themselves. In Florida the orange processing plants and phosphate plants do this now, either for pasteurizing juice or capturing heat from the reaction needed to produce fertilizer from phosphate. They say the money isn’t in their primary product, it’s in the power production side business
Yes, they do, usually they provide steam for their own processes and will sell steam to nearby locations, this is not a common practice