Inventors : Dr Viacheslav Sedunin, Deshraam Ganeshamoorthy, Whittle Laboratory
The inventors have developed a novel turbomachinery seal design that can become a key enabling technology for the hydrogen industry and small modular reactors (SMRs). In high pressure turbines and compressors working on gas and supercritical steam, the densities are extremely high, and seal leakages can account for 20–30 % of total losses.
Leakage from seals means that chemicals are lost, increasing costs and the risk of environmental contamination. Current tight seal solutions on the market require frequent maintenance and are limited in applications.
Conventional sectors such as aero-engines and power generation could also benefit, with improved seals expected to result in 1–3 % efficiency gains and more when closer to the end-of-life. This is a promising opportunity for such mature markets where even achieving a 0.5% efficiency improvement is seen as a huge change – reducing use of aviation fuel by just 1% would result in a saving of $80 billion a year.
The ideal seal clearance in turbomachinery is zero under steady operating conditions, but practical designs must accommodate a finite gap to avoid contact between rotating and stationary components. Seal clearances are therefore dictated by short-timescale effects such as vibration and misalignment, and longer-timescale effects including thermal growth and structural deformation. Consequently, sealing performance is limited not by steady-state requirements but by the need to survive both everyday and extreme transient events
The new technology is based on a pressure balanced structure that sits tight on the rotor during steady operation and adjusts itself during transients therefore allowing 5-10 times tighter gaps with the same flexibility as the current mass-market designs.
The technology has been proven feasible through a laboratory-grade prototype (TRL 4) operating under industry-representative conditions. A further prototype is being developed which will also include the inventors’ own control and measurement systems.
There are a range of possible applications in both mature markets and in new emerging technology areas, each of which has different needs. Therefore the challenge for the i-Team is to investigate the range of applications and markets for this new seal design, and recommend the inventors’ next steps towards commercialisation. This will include investigating the details of the operating environments for each application, and whether there are other requirements to make the product viable. Who would the inventors need to partner with to take their design into commercial turbines?