China introduced the diesel engine with a thermal efficiency of 53.09 percent

Since the invention of the Diesel internal combustion engine 127 years ago, a number of engineers and scientists have sought to improve the efficiency of the engine. As a significant step forward, the Chinese company Weichai Power presented the first diesel engine in history with an internal thermal efficiency of 53.09 percent.

The company presented its new technology at the 2024 World Congress of Internal Combustion Engines, which began in Tianjin, China. The performance was recognized by TÜV SÜD, an internationally recognized testing organization, and the China Automotive Technology & Research Center, an organization specializing in testing Chinese internal combustion engines.

Leading efficiency innovation

The thermal efficiency of the basic engine is known as the percentage of diesel combustion energy converted into useful engine work without the need for a waste heat recovery mechanism. The economy of the engine improves with the increased thermal efficiency of the base engine.

On September 16, 2020, Weichai Power introduced a diesel engine that set a new record with an efficiency of 50.23 percent. On January 8, 2022, the company made even more progress, raising the engine’s thermal efficiency to 51.09 percent. Most recently, on November 20, 2022, the company achieved a thermal efficiency of 52.28 percent, surpassing its previous records. The company compared it with current, standard products, which typically achieve an average thermodynamic efficiency of 46 percent. (The theoretical maximum efficiency of the Diesel cycle is 75%. Large two-stroke marine engines achieve 55% efficiency, truck engines 45%, standard passenger car engines 43% efficiency. Weichai Power’s result of 53.09% is therefore far above average above. – The ed.)

Fine-tuning of existing technologies

Building on previous successes, Weichai Power’s research team invested more than 500 days of concentrated work to optimize four vital systems: fuel supply, air intake, combustion and friction reduction. The team has effectively advanced high-expansion combustion, mixed-flow pressure equalization, high-efficiency fuel injection, and low-drag friction reduction technologies.

As a result of the experiment, the engine exceeded the 53 percent heat output limit for the first time in the world. According to the researchers, the result is comparable to a person running 100 meters in nine seconds. During the research and development phase, the group received 176 patents and 68 utility model protections.

Reduced fuel consumption

Modernizing the thermal efficiency from 45-46 percent to 53 percent can increase the economy of diesel engines by about 14 percent. This figure is based on current estimates of diesel engine ownership in China. This innovation results in approximately 31 million tons of fuel savings and a reduction of 97 million tons of carbon dioxide emissions every year.

A heavy tractor with a mileage of 250,000 kilometers can save approximately 45,000 liters of diesel fuel thanks to this technology. According to the team, this technical breakthrough will benefit not only transportation, but also other industries such as construction machinery, agricultural equipment, ships and power generation equipment.

(source)