JohnWeal
Mechanical
- Dec 16, 2012
- 124
Hello All,
We have 3 CHP engines that will provide heat energy to the hot water distribution circuit.
As a backup energy input, we have to install 2 hot water Boilers (duty / standby operation when called to run)
The boilers are each 2300 kW with burners that run on biogas and light fuel oil. The light fuel oil is a secondary fuel should Biogas not be available.
The boilers are non condensing 3 pass with a return temp of 60 deg C and flow of 71 deg C. There is a shunt pump arrangement should the water come back too cold.
The hot water according to the client standard design, will NOT be directed through the boilers. The CHP engines will provide the heat input by taking flow off the circuit using VSD pumps.
The boilers as I stated earlier are only a backup should the CHPs be down for maintenance or if biogas is not being produced and the boilers can provide heat with their secondary light fuel oil.
But the important thing is, is that the boilers can be inoperable for up to 12 months.
This is not the way I would like to see the circuit operated.
I prefer to split the flow 50% through each boiler. This keeps the boiler water moving through the system and regularly changed. Also the boiler is kept warm rather than cooling to ambient conditions in the boilerhouse which is at 5 deg C in winter.
There is no oxygen scavenger or water treatment plant being installed either.
Buy allowing 50% through each boiler (and only firing one boiler when needed) the pipelines can be reduced to 6” from 8”. Smaller valves too.
I would be grateful if anyone can share their experience for similar type of installations/ operations.
Regards
John
We have 3 CHP engines that will provide heat energy to the hot water distribution circuit.
As a backup energy input, we have to install 2 hot water Boilers (duty / standby operation when called to run)
The boilers are each 2300 kW with burners that run on biogas and light fuel oil. The light fuel oil is a secondary fuel should Biogas not be available.
The boilers are non condensing 3 pass with a return temp of 60 deg C and flow of 71 deg C. There is a shunt pump arrangement should the water come back too cold.
The hot water according to the client standard design, will NOT be directed through the boilers. The CHP engines will provide the heat input by taking flow off the circuit using VSD pumps.
The boilers as I stated earlier are only a backup should the CHPs be down for maintenance or if biogas is not being produced and the boilers can provide heat with their secondary light fuel oil.
But the important thing is, is that the boilers can be inoperable for up to 12 months.
This is not the way I would like to see the circuit operated.
I prefer to split the flow 50% through each boiler. This keeps the boiler water moving through the system and regularly changed. Also the boiler is kept warm rather than cooling to ambient conditions in the boilerhouse which is at 5 deg C in winter.
There is no oxygen scavenger or water treatment plant being installed either.
Buy allowing 50% through each boiler (and only firing one boiler when needed) the pipelines can be reduced to 6” from 8”. Smaller valves too.
I would be grateful if anyone can share their experience for similar type of installations/ operations.
Regards
John
