Heat management specialist Zircotec says it has launched research and development programmes to help commercial vehicle manufacturers deal with the increased exhaust temperatures needed for higher emissions standards.

The problem, they say, is significant: internal temperatures in some cases will rise from 500°C to more than 700°C, while the maximum external temperature ' currently as high as 480°C ' could be reduced to just 70°C by future legislation.

Finding a cost-effective way to meet these targets has become paramount for commercial vehicle manufacturers.

'Heat management is easy if the only requirement is to reduce heat loss and you have enough space to install sufficient insulation; however, that just isn't the case in most applications,' said Zircotec group sales director Graeme Barette.

'Conventional insulation would typically need to be up to 70mm thick to achieve the thermal barrier performance required. There is not room for such a thickness even with commercial vehicles, without re-routing the exhaust line and introducing knock-on effects that compromise other systems and overall packaging, to say nothing of the cost involved'

Zircotec, based near Oxford, is developing a range of solutions for several manufacturers, using its proprietary ceramic thermal barrier technology in innovative new ways.

The company is analysing each component of exhaust systems to identify ways of reducing heat transfer from the hot exhaust gas to the outer containment. This helps to maintain exhaust gas temperatures, speeds up cold-starts and the time taken for systems to warm-up. It also reduces the operating temperature of the containment structure, enabling a wider choice of more economic materials.

'One of our clients is aiming to maintain the exit gas temperature at no less than 87 per cent of the temperature at which it leaves the engine, for reasons of efficiency,' explained Barette.

'This requires us to minimise every possible source of heat loss; even the metal exhaust clamps can be significant in this respect and we are working on ceramic coating options with a leading clamp supplier'

Zircotec is looking at ways to integrate the ThermoHold, a ceramic-based heatshield coating, within the exhaust manifold. Prototypes have been produced by the manifold supplier at their facilities and early trials and the associated test results have been very promising, according to Zircotec.

Another key industry focus is on the thermal management of after-treatment systems to significantly improve conversion efficiency.

By using thermal barrier technology inside and around the DPF (Diesel Particulate Filter) and catalyst, the internal gas temperature can be increased, ensuring that heat is delivered and focused where it is most needed, while reducing external heat loss.

'Our experience in the thermal management of vehicle exhausts spans three decades and includes competition cars, supercars and motorcycles, but commercial vehicles are becoming an increasingly important sector for us,' said Barette.

'Our current research and development programs highlight the benefits for customers of working with us from an early stage to fully understand the different sources of heat loss and establish the most cost-effective solutions'