The Dynamic Performance and Control Strategy of a CO2 Transcritical Cycle for Waste Heat Recovery of Internal Combustion Engine

orc2019 Tracking Number 124

Waste heat recovery technologies are regarded as one of the most promising method to improve efficiency of internal combustion engines of trucks. Therein, CO2 transcritical cycle can make full use of waste heat of exhaust and jacket water at the same time under the design working condition. However, since the working conditions of trucks are complex, the waste heat recovery system also needs to work under different conditions. When the working condition of CO2 transcritical cycle changes, the properties of CO2 vary obviously and the cycle may not be able to use up the waste heat of exhaust and jacket water anymore. Therefore, a dynamic model of CO2 transcritical cycle which recovers both of exhaust and jacket water waste heat is established in this work by Simulink. After being verified by experiment data, the model is used to research the dynamic and off-design performance of the CO2 transcritical cycle. Based on these, a control strategy is proposed to help the cycle be able to recover the waste heat of exhaust and jacket water at the same time as much as possible.