Hot ideas: Revolutionary heat exchangers could hold the key to efficiency

Thermal management lies right at the heart of the drive towards greater efficiency. Electric powertrains and internal combustion engines alike can benefit dramatically from carefully optimised operating temperatures and reduced heat loss.  

Innovations in this area can have huge implications for a wide range of different applications. Hounslow-based thermal management specialist Hiflux applied to the APC’s Technology Developer Accelerator Programme (TDAP) to assist with bringing two promising new technologies to market.  

The first was a high-temperature compact heat exchanger originally conceived for micro turbine combined heat and power (CHP) systems. Hiflux had identified an opportunity to apply this concept to split-cycle engines, which use recuperators to recover significant amounts of waste heat from the combustion process. These engines have great potential in long-distance freight applications where combustion engines are expected to remain the dominant power source. In some cases, it’s estimated that they could lead to a 30 per cent reduction in COemissions and a 20 per cent drop in fuel costs. 

The other focus for the technology was developing ultra-compact heat sinks for power electronics on applications such as electric vehicles. These systems function most efficiently and most reliably within a specific temperature range, so there is a fundamental requirement for thermal management.  

Hiflux was awarded a grant of over £100,000 to pursue the development of these technologies, along with expert guidance, networking opportunities and access to TDAP’s delivery partners. As part of the project, the company worked with researchers at the University of Warwick and Imperial College London to investigate material properties. 


“TDAP put us in touch with the Compound Semiconductor Catapult, which pointed out that we needed more background science to back up our heat sink samples,” comments Hiflux Managing Director Tanzi Besant. “A lot of CFD and CHT work was carried out to understand things like pin spacing and dimensions that could be fed into our performance modelling.”  


The biggest benefit of the TDAP programme for Hiflux was the role it played in helping the company to evaluate potential markets, says Besant: “TDAP has provided a very important platform for us to investigate alternative markets. With the reduced resources we’ve had during the COVID pandemic we simply wouldn’t have been able to pursue both of these two projects without the APC’s help and encouragement.” 

Aided by the TDAP programme, Hiflux now intends to begin small-scale production of the high-temperature heat exchanger to support Dolphin N2’s development of a new split-cycle engine. The intention is to license external production for higher volumes. Meanwhile, samples of the heat sink technology are expected shortly, and the goal is to progress to commercial production within the next 18 months.