Hi,
We are in the process of finalizing the flare system for our upcoming refinery in India. After identifying the controlling load we have found that flare load is very high from the Cracker complex (for cooling water failure case). Our primary motive is to avoid additional cost incuured via having a seperate flare header for the cracker complex. in line with this can you suggest ways of mitigating flare load giving examples of case studies.
Thanks
B Mukund
M A M Krishnen
Process Engineers
HMEL
Full Version: Flare Load Mitigation
HIPPS comes to mind in minimizing relief loads.
You might as well consider that option.
You might as well consider that option.
HIPPS philosophy - as seen in Oil&Gas production facilities - is not applicable in refinery environment. As an ultimate protection, configure the flare system in such manner it can handle full process load. And, in my opinion, this step should be done after configuring ESD systems and power/utility supply system modes of operation; or even before that, but at least having the idea what it will look like.
1. Power supply network should be redundant - having at least two, or three independent sources. In the case of power grid failure, alternative power supply is automatically provided, and your pump/compressor/fan motors will continue to run.
2. Equipment sparing philosophy. A good practice is to provide different (motive) sources for equipment in critical service. For example, consider having both electrical and steam turbine-driven pumps, compressors etc. It's not very likely that two systems will both fail at once.
3. Configure plant ESD systems in such way they respond fast and logical, ensuring maximum protection. This means you need to account for automatic shutdown of all process equipment which generates heat and takes it into the system (i.e. fired heaters), while heat removal sections should be fully relaxed (i.e. 100% opening of louvres in air-coolers, pumparound control valves etc.)
After assessing these items, you'll see that estimated (the most conservative load) is very high, as compared with the one resulting from the optimum power/utility/sparing/ESD philosophy. And early design stage is the right moment to deal with all these subjects.
1. Power supply network should be redundant - having at least two, or three independent sources. In the case of power grid failure, alternative power supply is automatically provided, and your pump/compressor/fan motors will continue to run.
2. Equipment sparing philosophy. A good practice is to provide different (motive) sources for equipment in critical service. For example, consider having both electrical and steam turbine-driven pumps, compressors etc. It's not very likely that two systems will both fail at once.
3. Configure plant ESD systems in such way they respond fast and logical, ensuring maximum protection. This means you need to account for automatic shutdown of all process equipment which generates heat and takes it into the system (i.e. fired heaters), while heat removal sections should be fully relaxed (i.e. 100% opening of louvres in air-coolers, pumparound control valves etc.)
After assessing these items, you'll see that estimated (the most conservative load) is very high, as compared with the one resulting from the optimum power/utility/sparing/ESD philosophy. And early design stage is the right moment to deal with all these subjects.
QUOTE (Zauberberg @ Aug 27 2008, 11:43 PM) 
HIPPS philosophy - as seen in Oil&Gas production facilities - is not applicable in refinery environment. As an ultimate protection, configure the flare system in such manner it can handle full process load. And, in my opinion, this step should be done after configuring ESD systems and power/utility supply system modes of operation; or even before that, but at least having the idea what it will look like.
1. Power supply network should be redundant - having at least two, or three independent sources. In the case of power grid failure, alternative power supply is automatically provided, and your pump/compressor/fan motors will continue to run.
2. Equipment sparing philosophy. A good practice is to provide different (motive) sources for equipment in critical service. For example, consider having both electrical and steam turbine-driven pumps, compressors etc. It's not very likely that two systems will both fail at once.
3. Configure plant ESD systems in such way they respond fast and logical, ensuring maximum protection. This means you need to account for automatic shutdown of all process equipment which generates heat and takes it into the system (i.e. fired heaters), while heat removal sections should be fully relaxed (i.e. 100% opening of louvres in air-coolers, pumparound control valves etc.)
After assessing these items, you'll see that estimated (the most conservative load) is very high, as compared with the one resulting from the optimum power/utility/sparing/ESD philosophy. And early design stage is the right moment to deal with all these subjects.
1. Power supply network should be redundant - having at least two, or three independent sources. In the case of power grid failure, alternative power supply is automatically provided, and your pump/compressor/fan motors will continue to run.
2. Equipment sparing philosophy. A good practice is to provide different (motive) sources for equipment in critical service. For example, consider having both electrical and steam turbine-driven pumps, compressors etc. It's not very likely that two systems will both fail at once.
3. Configure plant ESD systems in such way they respond fast and logical, ensuring maximum protection. This means you need to account for automatic shutdown of all process equipment which generates heat and takes it into the system (i.e. fired heaters), while heat removal sections should be fully relaxed (i.e. 100% opening of louvres in air-coolers, pumparound control valves etc.)
After assessing these items, you'll see that estimated (the most conservative load) is very high, as compared with the one resulting from the optimum power/utility/sparing/ESD philosophy. And early design stage is the right moment to deal with all these subjects.
Dear Mukund Balachandaran Hello/Good Afternoon,
Just adding slightly to what has been justifiabely pointed out/suggested by Zauberberg
A thorough conceptual Overall 'Vented to Flare system' loads survey be conducted and wherever their diversion to Fuel gas or Flaregas recovery systems is possible should be routed to such destinations/eqipments.
Moreover the Most Important/Critical Cooling System/reflux Streams Pumps and other Finfan coolers Power must be kept secured as rightly pointed out by Zauberberg.
The overall control valve Failure to close and Open stratagy is also to be very thoroughly checked/reviewed to serve this objective.
Hope this helps
Qalander
This is a "lo-fi" version of our main content. To view the full version with more information, formatting and images, please click here.