An indirect heating solution to reduce CO2 emission and improve efficiency of gas distribution networks

The gas industry relies on indirect heating to prevent gas from freezing when it is transferred from high-pressure networks to lower pressure distribution systems. The main challenge in preheating natural gas is designing an indirect heating system capable of consistently maintaining a target temperature, despite large load diversity. The most common form of heating technology has traditionally been water bath heaters and boiler houses. In this paper, a novel technology is introduced, and its performance compared to existing installations. The Immersion Tube Thermosyphon Heater was developed specifically to address high load diversity; it combines a high-efficiency immersion burner with a sub-atmospheric two-phase loop thermosyphon. The use of low-temperature steam provides a flexible and precise solution for temperature control easily adapted to variable gas flows. The Immersion Tube Thermosyphon achieved an average thermal efficiency of 90%, considerably higher than the 46% efficient water bath, allowing an estimated annual saving of 7,660 tonnes CO2 for 1-megawatt gross heat capacity operating with a 50% load factor.