SPS was used to provide fuel tank thermal insulation on three tankers, delivering:

• Cost effective insulation of boundary between adjacent HFO and MGO tanks
• Maximum HFO and MGO tank capacity due to compact thickness of SPS
• No changes to existing structure
• Zero through-life maintenance

Carried out in Qatar by SPS Technology Network Partner, CTSOM, each of the three ships had 50m2 of SPS fitted to bulkheads between two adjacent fuel tanks. This was the first time Sandwich Plate System had been used in this type of application.

The SPS elastomer core provides an efficient thermal barrier while maximising available storage capacity, as there is no need for void spaces between tanks or changes to the ship’s structure. The standard SPS specification uses an 8mm steel top plate with a 40mm elastomer core.

The tankers each needed a thermal insulation boundary installed between two Heavy Fuel Oil (HFO) tanks to create a Low Sulphur Marine GasOil (LSMGO) tank as part of the ship owner’s strategy to meet new exhaust gas emission requirements.  IMO MARPOL 73/78 Annex VI had been amended to require new standards for marine fuel oils when vessels are operating in defined Emission Control Areas (ECA; as defined by the IMO), specifying a reduction of the sulphur content (SOx) to below 0.1% from January 2015.

Care must be taken to keep LSMGO fuels cool enough to maintain viscosity and avoid operating problems. For HFO tanks, the required viscosity is achieved by heating the fuel up to 90degC, whereas MGO should be stored at temperatures below 40degC. Therefore a layer of insulation is necessary between the adjacent tanks, to maintain optimum storage temperatures.

In this project, the Owners proposed to add LSMGO storage tanks to a series of vessels, but were concerned that the proximity of the HFO tanks may result in the LSMGO exceeding the maximum allowable temperature of 50°C, or 10°C below the fuel’s flash point.

It was established that the insulating properties of SPS’s elastomer core reduced the rise of the LSMGO temperature.

Lloyd’s Register EMEA’s Technical Investigation Department (TID) modelled heat transfer through a proposed LSMGO storage tank on a series of vessels. The assessment of the thermodynamics of the vessel in the vicinity of the tanks was carried out by both:

  • a simplified thermodynamic calculation, taking into account conduction only;
  • as well as a much more complex approach with a three-dimensional heat transfer CFD modelling capturing both conduction and convection.

The results from these analyses showed that:

  • the mean LSMGO temperature will not exceed 50°C under normal operating conditions;
  • the rate of temperature rise of the LSMGO is less than 2°C/month.

Read more about how SPS was used to create Enhanced Oil Recovery Tanks onboard the FPSO Glen Lyon.

Please see more about SPS Technology Maritime and Offshore projects. Or, follow us on LinkedIn.