This article appeared in the March 2019 (Vol.14, No.3) issue ofChina Automotive Review (CAR), our monthly publication in English exclusively focused on the Chinese auto industry. If you would like to read this information-packed monthly report on the Chinese automotive market (in PDF format on a paid basis), please send your subscription to us at: sub@cbuauto.com.cn

As new energy development is in the fast lane, pressures on traditional power sectors are getting heavier and heavier. Under such circumstance, Tan Xuguang, chairman of Weichai Group, honorary chairman of China Internal Combustion Engine Industry Association, expressed his views and opinion on the prospect of diesel engines in an article published in Science and Technology Daily on February 14. The following are highlights of the article. – Editor

Diesel engine's key role in the national economy

Diesel engine is one of the most important inventions in power industry in the course of human history. After more than 100 years of development, diesel engine technology has achieved many breakthroughs in energy saving and emissions reduction, becoming the major power application in many fields including commercial vehicles, construction equipment, agricultural machinery, boats and ships, and military vehicles with majority share in the power market. According to data from the Ministry of Transport, highway transport conducted by diesel-powered vehicles took 78.8 percent of total national passenger transport volume and 78 percent of total national freight volume in 2017, supporting the high-speed development of China's national economy.

With the reform and opening-up, China's diesel engine industry has achieved remarkable progress and development. Sales of vehicle diesel engines in the Chinese domestic market increased from 631,100 units in 2000 to 3,575,200 units in 2017. Through independent technology innovations, the diesel engine industry has caught up with the advanced international level, even leading the industry in some areas in the world. This is why Chinese brand commercial vehicles have taken up over 99 percent of the market share in the country, leaving only a tiny room for products from international commercial vehicle giants, and realized volume export.

The irreplaceable nature of diesel engines

Over recent years, fast development of new energy technologies has brought a huge pressure on the diesel engine industry. However, it must be recognized that new energy technologies will not be able to completely replace diesel engine technology for a very long period of time in the future.

Most diesel-powered vehicles and machines require engines equipped on them to generate high power and operate continuously for a long time. Since new energy technologies are still in the development stage, they currently can only be applied in some specific segment markets such as public transport buses, municipal vehicles and terminal tractors.

As current energy densities of lithium batteries are not high enough, it is difficult to promote the application of pure electric technology to heavy-duty commercial vehicles. Take a gross weight of a 49-ton heavy-duty tractor as an example. Based on the current practical conditions on market, to electrify the 49-ton tractor, the power density of the lithium battery pack has to be 3,000 kWh. Even the lithium battery pack meets China's planned objective, the battery weight will still be about 11 tons with cost of ¥3 million and long charging hours, having no practical application value.

Hydrogen fuel cell technology is regarded as the possible development direction in the heavy-duty commercial vehicle power sector. But current conditions in hydrogen production, transport, storage and refill cannot support the wide application of hydrogen fuel cell batteries. According to estimates from international hydrogen energy organizations, application of fuel cell batteries in heavy-duty commercial vehicles will not exceed 20 percent by 2050.

The quick development of new energy technologies has forced the diesel engine industry to accelerate technology innovation and product upgrade. New energy power equipment and diesel engine will complement each other for a long time, as they are not simply competitors for zero emissions requirement.

Diesel engine plays huge role in energy saving and emissions reduction

With the steady progress in technology, diesel engine has played a huge role in energy saving and emissions reduction with enormous potential to make further improvement in these areas.

Fuel consumption of diesel engines is getting lower now. Compared with other power devices, diesel engine has notable energy saving effect, as it has the highest energy conversion efficiency. Based on the latest research findings, there are already commercial possibilities to increase diesel engine's thermal efficiency to 50 percent from the current 45 percent and realize close to zero emissions. If the thermal efficiency of diesel engines can achieve that increase, whole vehicle fuel consumption will be reduced by 11 percent, which means about 19 million tons of diesel fuel will be saved annually, reducing CO2emissions of about 60 million tons by the entire society. With more advanced technologies including high efficiency combustion and heat recovery, it is possible to increase diesel engine's thermal efficiency to 55 percent to further lower the whole vehicle fuel consumption by 22 percent from the current level and reduce diesel fuel consumption by about 38 million tons and CO2emissions about 120 million tons per year by the entire society.

Pollutants emitted from diesel engines have been gradually reduced since China I emissions standards began to take effect in 2000, and China VI emissions standards will be implemented starting in 2019. Compared with China I emissions standards-compliant diesel engines, particulate matter and NOX emissions from China VI diesel engines have been cut by 97 and 95 percent respectively. This indicates commercial possibilities to realize zero emissions to further decrease pollutants from diesel engines. The next step is to implement nationwide China VI emissions standards for on-road diesel engines and Phase IV emissions standards for non-road diesel engines and accelerate the replacement of those diesel-powered products with high pollutant emissions levels available on market, so as to help push consumers to upgrade their demand for those diesel-powered products with low fuel consumption and pollutant emissions.

Summary

With continued technology breakthroughs, diesel engines will still dominate the fields such as heavy transport power, large industrial fixed power, marine power, construction equipment, agricultural machinery and military vehicles, having huge market demand and tenacious vitality in the next few technology development stages. Advanced diesel engine technology will still play an indispensable role in energy saving and emissions reduction as well as in coping with climate change. Predicably, in the next 50 years, diesel engines will still thrive.

(Translated by San Shi based on author's article in Science and Technology Daily)

The above article appeared in the March 2019 (Vol.14, No.3) issue ofChina Automotive Review (CAR), our monthly publication in English exclusively focused on the Chinese auto industry.