Energy saving and emission reduction in road transport field is an important part of the strategy to achieve carbon neutrality. Heavy commercial vehicles have high power and range requirements

and the transition from conventional internal combustion locomotives to hybrids with waste heat recovery is of great significance in improving engine efficiency and reducing energy consumption. However

the waste heat recovery system integrated with hybrid power in current research mostly adopts a simple layout

and only recovers a single form of waste heat energy from the cylinder liner water or flue gas

which has a limited degree of enhancement to the overall efficiency of the vehicle. Therefore

a waste heat recovery system based on the organic Rankine cycle that can simultaneously recover the waste heat from flue gas and cylinder liner water and operate efficiently under full operating conditions is proposed. The system is coupled with a series hybrid power system and operates under high-speed and suburban road conditions

the performance of the organic Rankine cycle system and the improvement effect of the overall energy efficiency of the integrated system are then investigated. The results show that

under the premise of considering the weight of the waste heat recovery system

the waste heat recovery system improves the engine efficiency by 2.85% and reduces the overall fuel consumption by 6.78% under high-speed USHWY conditions.Under urban road UDDS conditions

it enhances the engine efficiency by 2.30% and decreases the overall fuel consumption by 6.43%. The above results demonstrate the system's fuel-saving capability and application potential.It is found that the organic Rankine cycle system has a large inertia

and the long-term stable operation of the engine plays a decisive role in improving the output power and efficiency of the system

so the system is suitable for matching with high-speed operation of heavy-duty hybrid vehicles.