Exhaust Gas Heat Recovery

The need to reduce CO2 emissions has led to significant improvements in passenger vehicles over the past decade. With engine optimisation and aerodynam­ics now starting to reach their limits, the focus is shifting towards the recovery of thermal energy.
During engine warm-up, efficiency is very low, so faster warming of the internal combustion engine can greatly increase engine fuel efficiency.

BOSAL tackles this by recovering up to 75% of the engine exhaust thermal energy which would otherwise be lost. This thermal energy is used to rapidly heat up the engine at cold start. This eliminates the need for any external electrical, mechanical or thermal energy source. The modular design of the system can be used across car platforms and various engines. The system brings substantial fuel cost savings for the end user, while also delivering significant CO₂ reduction.
In addition, faster window defogging and heating of the vehicle cabin help to improve passenger safety and comfort.

The exhaust gas heat recovery system consists of 2 parallel flow paths, which are regulated by a double valve, providing 2 modes of operation: heat recovery and bypass. In heat recovery mode, the exhaust gas passes through the heat exchanger, which then recovers the thermal energy and transfers it to the engine coolant. In bypass mode, the exhaust gasses flow through the bypass and no heat is recuperated. Careful tuning of the dual valve design results in extremely low parasitic heat.

The functional component of the system - the heat exchange core - is composed of a patented plate design with a high rate of effectiveness - up to 75%. The modular sys­tem design allows stacking of the plates in lower or higher quantities to accommodate engine requirements, with minimal further design changes to the system.