The Konkan LNG terminal facility, located near Dabhol on the west coast of India, includes a LNG receiving terminal, storage tanks and a regasification plant. It is designed for a nominal throughput of 5 MMTPA of Liquefied natural gas (LNG). The receiving terminal consists of a jetty, a breakwater, and unloading arms which are the equipment necessary to transfer the LNG from incoming tankers to the onshore storage tanks. Shipboard pumps are used to transfer LNG from the ship to shore side facility. The transfer is accomplished through three 16” liquid unloading arms to a manifold and then via two 32” insulated lines to the two storage tanks located in the cove.
The LNG is unloaded through three unloading arms utilizing the ship’s send out pumps, which then flows to shore and into the LNG tanks. All vapors boiling off from the tanks is compressed via the Boil off Gas (BOG) compressor and returned to the ship to replace the volume of the off-loaded liquid. Because of the high unloading rates with LNG transfer, vapour must be continuously returned to the cargo ship during the unloading process to maintain a constant tank pressure of 1.L3 bar. The vapor, regulated to 2.0 bar atm is de-superheated by injecting LNG under temperature control. The cold vapors then flow through a 16” unloading arm back to the ship’s manifold where the vapor is regulated back into the individual spheres to maintain pressure. The liquid unloading pipe network is kept cool by recirculating LNG using the in-tank pumps and returning the warm liquid to the BOG Condenser, when LNG is not being unloaded. The LNG unloading arms are cooled down by a flow prior to any unloading operations.
The Fire risk Assessment study of the facility is conducted to evaluate the potential risk levels for personnel and equipment due to accidental release of hazardous materials from loss of containment scenarios from the facilities.
The FRA Study Methodology is as follows:
- Identification of Fire Hazard events.
- Calculation of physical effects of failure case scenarios which include Estimation of Flash Fire, Jet Fire, Pool Fire heat radiation distances.
- Determination of the fire zone, fire proofing requirements for Structures, Vessels & Equipment’s.
- Determination of the Critical Equipment that falls under the Fire Zone.
- Recommendation of risk reducing measures to ensure that all Equipment, Vessels & Structure are Fire safe.
- Analysis of the risk due to Inter-Separation issues.