Introduction: To design, construct and install two innovative pre-heaters with heat output capacities of circa 100kW and 326kW, compliant with UK legislation and standards.

The pre-heaters will be innovative for four main reasons:

• They will operate in a vacuum, i.e. in the presence of low levels of oxygen, which minimises corrosion, extends asset life and the water boils at a lower temperature meaning less energy input is required for indirect heat transfer. As less water is used than in conventional systems, heat can be better directed over a range of loads, resulting in higher efficiency while reducing the physical size to a compact footprint

• Energy inside the system will be transferred indirectly, without the use of pumps or motors, by means of a heat cycle call a thermosyphon resulting in improved reliability with fewer moving parts than conventional preheating systems, therefore maintenance frequency and likelihood of breakdown is reduced

• The compact pre-heating units will reuse process connections and civil supports from existing water bath heaters, thereby reducing complexity and cost associated with pre-heater replacement

• They will employ novel burner design which offers the same efficiency as modular boilers with a simplified industrial design for long life and ease of service. This burner technology has not previously been utilised for gas-preheating.

Objectives:

The key objectives of this project are outlined below: 

• Fabricate a 100kW and a 326kW compact natural gas pre-heating unit that are compatible with the UK gas distribution system.
• Install and field trial the two prototypes on SGN sites.
• Demonstrate that the new pre-heaters have better thermal efficiencies than current pre-heating systems.
• Demonstrate that the new pre-heaters can successfully repurpose existing civil and process connections to reduce installation costs associated with pre-heater replacement.
• Demonstrate that the new pre-heaters have less CO2 emissions than other systems currently available.
• Quantify anticipated lifecycle cost savings through a combination of reduced failure, reduced installation cost, improved serviceability, improved design life and higher efficiency.
• Produce a report detailing the results of the trials.

Expected Benefits: In order to quantify the benefits of this project, performance comparisons will be made against an existing preheating plants operated by SGN to examine efficiency, emissions and life-cycle ownership costs including capital cost, installation cost, fuel use and maintenance.

The project will be deemed to be successful if the field trials enable assessment of the extent to which the new pre-heaters:

• Are compatible with the UK gas distribution system

• Have better thermal efficiencies than the current pre-heaters onsite

• Have a lower installed capital costs than modular boilers as a replacement option

• Have lower operating costs than other systems currently available

• Show a marked reduction in fuel usage

• Show marked reduction in carbon emissions

• Improve system reliability and design life as compared to modular boiler pre-heating plants.