HiETA Technologies Recently Tested Our Novel Waste Heat Recovery System

HiETA Technologies recently tested our novel waste heat recovery system, as part of a collaborative R&D project with Bath University and AXES Design, generating over 1kW of power from an exhaust stream.

As part of an Innovate UK project, we have developed a waste heat recovery system based on an Inverted Brayton Cycle, aiming to deliver ~5% fuel savings for an automotive internal combustion engine over a standard drive cycle (with other applications in the off-road, train, marine and industrial power markets). The system imparts no back pressure on the engine and uses low-cost products to deliver the energy and weighs less than 10kg, offering significant advantages over technologies such as turbo-compounding, thermoelectric generation, and organic Rankine Cycles.

The consortium designed, built and tested a prototype system in the state-of-the-art hot gas stand at Bath University, and simulated a range of driving conditions from a 2.0L gasoline engine. We tested a basic system comprising a turbine, heat exchanger and compressor, followed by a more complex system that condenses water from the exhaust flow and re-uses it to create superheated steam.

We have used Additive Manufacturing (metal 3D printing) to manufacture a high-efficiency heat exchanger, an Inconel turbine housing and an aluminium compressor housing. The system generated over 1kW of power, with further testing taking place this year predicted to generate up to 5kW of power. We are also now integrating an electric machine and steam turbine to complete the system, and looking for opportunities to demonstrate this on a vehicle as soon as possible.

Test cell with prototype heat recovery unit (below).

Waste Heat Recovery System