CASE STUDY

Fire System Adequacy for three sheds and to Study the hydraulics of IOCL Cochin

Project Brief:

Indian Oil Corporation Limited (IOCL) LPG Bottling plant, Kochi has entrusted M/s iFluids Engineering to study the existing fire water arrangements and its adequacy inside the bottling plant sheds. The existing firewater network has 26 different fire zones with deluge valve actuations. Sprinkler arrangements and Fusible loop connections for fire detection are available in the plant. M/s iFluids Engineering conducted the detailed site survey for existing fire water arrangements As-Built drawings, Pressure monitoring and other required data collection to check the adequacy of existing Fire water arrangements.

Facility Brief:

Indian Oil Corporation Limited (IOCL) LPG Bottling plant – Kochi consists of the following facilities.

  1. Filling Shed – 3 Nos. with Carousel
  2. Loading Shed – 3 Nos.
  3. Unloading Shed – 3 Nos.
  4. Storage Yard
  5. Maintenance Yard
  6. Tank Truck Gantry (12 Bays)
  7. Mounted Bullet Area

Execution Methodology:

Data Collection

  • PFD & P&IDs of the Firewater arrangement including Fire Water tanks.
  • Fire water system overall layout for the Process units.
  • Isometric and Piping GAs for firewater network showing sprinkler system for each facility.
  • Equipment datasheet for Water monitors, hydrants, deluge valves, HVLR’s and orifice plate.
  • Fire Water sprinkler system for storage tanks details including the K factor of sprinkler nozzles   Number of water sprinkler rings in each area.
  • Firewater pump datasheet including Main and Jockey pump.
  • Fire Water Piping specifications.
  • Operating philosophy of fire water system.
  • Fire and gas philosophy and its cause and effect, showing fire zones with respect to their deluge valves opening.
  • Existing Hydraulic analysis Report (if available)
  • PFD & P&IDs of the Foam System for facilities fire water arrangement including Fire Water tanks.
  • Isometric diagrams and Piping GAs for Foam network.
  • Foam system operating philosophy and pump datasheet.

 Hydraulic Study Procedure

  • Hydraulic analysis of firewater systems were modelled in software, in compliance with NFPA13, NFPA15 and NFPA16 rules.
  • Fire water equipment such as Water monitors, hydrants, deluge valves, HVLR’s and orifice plate data to be feed.
  • Fire water pump including main & jockey pump characteristic curve to be incorporated for pressure and flow rate from the pump house.
  • Fire water pipeline data will be taken from piping class specification.
  • Firewater flow line size and line length is incorporated from overall layout file or site survey report.
  • Firewater model is primarily drawn from pump house and flow lines are extended to respected main headers & sub headers.
  • Initially Firewater pumps are drawn from characteristic curve & optimized for BEP. Checked for output pressure, flow rate & Efficiency.
  • Overall layout of the firewater network is drawn adding Water monitors, hydrants, deluge valves, HVLR’s and orifice plate in the main header and sub header flow lines.
  • Fire water flow lines is extended to each Process facilities and storage tanks. Similarly, Water monitors, hydrants, deluge valve, HVLR & orifice plate is added.
  • Similar to fire water network, foam system is added to storage tanks along with the nozzles.
    • While adding nozzles such as water monitor, hydrant, deluge valve, HVLR, should be checked for off position.

Software Modelling

  • Performing the pipe network modelling
  • After modelling, include the flow lines for all the facilities along with the nozzle and sprinkler system, model should be corrected for any errors if occurred.
  • The modelling should be run for two simultaneous fire and HVLR, Monitor, hydrants to be opened as per NFPA. All other sections of the facility nozzles to be in off conditions or the scenarios will be considered as per Client provided details for worst case scenario.
  • Fire water pumps to be checked for flow, pressure and the number of pumps to be line depends upon the fire water demand, pump capacity and the fire water flow line network.
  • Iterations to be done in flow line size i.e., main header or sub headers based on the required pressure and flow rate in a section.
  • Flow lines should also satisfy the velocity limit given in NFPA. Iteration to be done flow line size if the velocity exceeds. Optimization to be done such that given pressure and velocity is achieved for a given flow rate.
  • Followed by iteration in Flow lines, iterations to be done in Fire water main pumps and jockey pump to be added even if required flow rate and pressure is not achieved.
  • Fire water demand calculations to be performed for each storage tanks, bullets, storage spheres & Process units as per NFPA.
  • Minimum fire water storage should satisfy the fire water demand for fire fighting as per NFPA.
  • Foam requirement in specified storage tanks to be satisfied.

Outcome of the Study

  • Pipe sizing for new and retro fire water pipe networks.
  • Calculation of pressure drop in fire water pipes for existing piping networks.
  • Calculation of velocity in fire water flow pipes.
  • Selection of fire water main pump, jockey pump & restriction orifices.
  • Ensuring that all consumers will get the demanded amount of fire water for distribution networks.
  • Ensuring that all nozzles get desired water flow rate and pressure for fire-protection network.
  • Fire water demand for fire protection.
  • Hydraulic analysis.