The one-dimensional transient simulation model of a heavy-duty diesel engine cooling system was established by using GT-SUITE software

and the control strategy and control effect of the cooling system were studied. In order to reduce the energy consumption of the cooling system and improve the accuracy of coolant temperature control

three control strategies combining the mapping feedforward and three different fuzzy control feedbacks were designed

including the fuzzy control feedback

variable-universe fuzzy control feedback and variable-universe fuzzy control feedback with pump speed proportional integral control. Then

according to the worldwide harmonized transient cycle(WHTC) conditions

a simulation calculation and its comparison with the engine bench test and vehicle operation were carried out. Results show that compared with fuzzy control feedback

use of variable-universe fuzzy control feedback can reduce the variation of the engine coolant outlet temperature by 37.6%

and increase the duration of water temperature control within the range of ±0.5℃ by 39.98% coupled to the reduction of the total energy consumption of the cooling system by 8.58%

thus resulting in a significant improvement in cooling performance. In particular

by using variable-universe fuzzy control feedback with pump speed proportional integral control

the engine coolant outlet temperature can be further reduced by 16.1%

and the duration of water temperature control within the range of ±0.5℃ is increased by 15.26%

but the total energy consumption of the cooling system is also increased by 10.3%

so that the temperature control accuracy is improved at the expense of energy consumption. In summary

compared with fuzzy control feedback

use of variable-universe fuzzy control feedback has the best overall performance in terms of the temperature control accuracy and energy consumption

which improves the temperature control accuracy by 49.28% during vehicle operation

and reduces the energy consumption of the cooling system by 8.68%.