A Skin Effect Heat Management System (SEHMS) is an engineered system designed to maintain or protect waxy Crude Oil pipe at pre-determined temperatures and within defined design criteria.
SEHMS generates heat on the inner surface of a carbon steel heat tube that is welded to the carrier pipe to be heat traced, however crude oil pipeline is insulated with 90 mm Poly Urethane Foam (PUF) to arrest the heat loss from pipeline to the surrounding soil and further enclosed with a 5 mm HDPE jacket .
SEHMS works on the principles of skin and proximity effect for operation which is established and proven electrical heating technology used for long distance pipelines.
The key SEHMS elements are transformers, heat tube, pull boxes, end boxes, and temperature sensors.
Produced RJ crude oil in India from Mangala Field which is waxy in nature and gets solidified around 45 Deg C requires continuous heating. World’s longest, (700KM) continuously heated and insulated 24” pipeline from Mangala Process terminal in Barmer, Rajasthan, India is being operated with SEHMs technology and supplying the crude oil to various refineries in India.
A Scott-T transformer (also called a Scott connection) is a type of circuit used to derive two-phase power from a three-phase source or vice-versa. The Scott connection evenly distributes a balanced load between the phases of the source hence the total real power delivered to the two phase load is equal to the total real power supplied from the three-phase system.
A LBU (Load Balancing Unit) circuit used to distributes the equal power to both the side of Power source connected with transformer.
Advantages of SEHMS
- Embedded heating
- Minimal maintenance
- Cold re-start capability
- Remote Emergency Shut-down capability
- High Waxy Crude.
- Ship loading/unloading lines
- Piping partially or completely underground/sub sea/submerged lines
- Frost Heave Prevention