Research Progress on Engine Coolant Under the Background of Carbon Neutrality

With the implementation of the “dual carbon” strategy, low-carbon and compact engine development is an inevitable trend. At the same time, the cylinder pressure and temperature of the engine continue to increase, and the heat load also increases, which puts higher requirements on the engine coolant. In this paper, the standards, performance requirements, and types of engine coolant have been introduced. Then, for commercial coolant, the properties of coolant base fluids and additives have been analyzed. Further, for novel coolant, the properties and application effects of nanofluids and phase change fluids in engines have been emphasized from heat transfer characteristics, heat carrier densities and flow resistance characteristics. Finally, the challenges faced by engine coolant and future development directions were proposed. In the future, coolant recovery, modification of anhydrous coolant worth further exploration. And further research is needed for performance improvement of nanofluids and phase change fluid and their applications in engines.