[YesAuto technology] Recently, Honda and a test equipment company and Tsinghua University conducted an exhaust emission test on their Accord Hybrid. The test data showed that the amount of HC contained in the exhaust gas emitted by the Accord Hybrid was actually lower than The test value of the main road area of Beijing's Third Ring Road. Seeing this result, some people joked that “cars have become air purifiers”!
Judging from this result alone, it is indeed easy to be misunderstood that Accord Hybrid's exhaust gas is cleaner than the atmospheric environment, but in fact, this test only tests the HC concentration in the exhaust gas and the air, as for the other two in the exhaust gas. The main pollutants, carbon monoxide and nitrogen oxides are not in this test, and the three-way catalyst we often say is around these three substances for catalysis. Not only that, we all know that fuel combustion is a very complicated process. In addition to the test items specified in the regulations, the exhaust gas also contains unconventional pollutants. These substances not included in the test also have varying degrees of pollution to the environment. . In summary, the argument that “cars have become air purifiers” is clearly untenable.
● Why is the HC value so low?
To be sure, the Accord Hybrid does control the HC emissions very well, which is also a major advantage of the hybrid system itself. In traditional cars, the internal combustion engine must continuously adjust its speed as the vehicle runs to meet the needs of power output. In contrast, the hybrid power system “isolates” the direct relationship between the engine and the power through the way the electric motor drives the wheels. Under such conditions, the engine can always maintain a high efficiency state, and then give full play to the efficiency advantages of the Atkinson cycle.
In addition, the engine can also use this to heat the three-way catalytic converter so that it reaches the operating temperature as soon as possible. In this way, the catalysis of HC substances can be completed faster, and the data in the exhaust gas will naturally be controlled at a relatively low level. Low range.
● About the development of hybrid vehicles in China
Looking up at the sky, I have to admit that the problem of environmental pollution is at hand, which has also promoted the rapid development of new energy vehicles in the past two years. So, should we develop pure electric or focus on catching up with Japanese companies in the field of hybrid technology? Under the policy guidance in recent years, Chinese brand manufacturers have chosen a relatively suitable technology route based on their current technology reserves. For hybrid technology, this needs to be built on the basis of existing traditional power technologies, for example, Maintaining the Atkinson cycle on the traditional engine structure, integrating the motor in the gearbox, etc., due to the lack of mature technology development and application in traditional power, this has led many manufacturers to invest in the development of pure electric vehicles in advance.
Coupled with the differentiated subsidy policies for new energy vehicles in various regions, especially in Beijing, hybrid vehicles are excluded from the new energy subsidy policy, which strengthens the determination of manufacturers to develop more resources towards pure electric vehicles.
Through our understanding, at the beginning of the formulation of the new energy subsidy policy and lottery rules, we also considered granting more “privileges” to hybrid vehicles, but the final decision now seems to be basically consistent with the original assumptions of the relevant departments. Related speeches People use the survey results in Shanghai to illustrate this point. Since hybrid power can enjoy a series of subsidy and preferential policies in Shanghai, the sales of hybrid models represented by BYD Qin are significantly better than those in other regions, which also drives local new cars. However, according to recent survey results, more than 90% of hybrid vehicles are being used in the same way as traditional gasoline-powered vehicles. This is related to the immature charging infrastructure in the region, and the weight of hybrid vehicles is due to the lack of batteries. Because it is heavier than ordinary gasoline engines, hybrid vehicles may consume more fuel when gasoline engines are working. This result is contrary to the goal of alleviating traffic pressure and air pollution pressure set by the Beijing area.
Despite the good policy form, whether pure electric vehicles are suitable for current development has become a topic that many people are discussing. In addition to the battery life and charging issues during daily use, the topic about whether electric vehicles can truly reduce emissions The same is true, and we will discuss this topic in detail in a separate article in the future.
Japanese manufacturers have made early investments in hybrid technology, especially Toyota. After completing the localization of hybrid system components, the hybrid versions of Corolla and Ralink have broken people’s grievances about hybrids in terms of price. Now Honda will also introduce the Accord Hybrid into domestic sales next year.
Corolla 2016 Dual Engine 1.8L CVT Flagship Edition
Ralink 2016 Dual Engine 1.8HV CVT Deluxe Edition
In fact, no matter what kind of technology the car adopts, the ultimate goal is to reduce the impact on environmental pollution. Although Honda’s exhaust gas test on the Accord Hybrid has produced some ironic statements, it can give us an updated understanding of car exhaust. In addition to the several parameters specified in the testing regulations, some unconventional types The pollutants actually have a certain impact on the environment. Another thing worth mentioning is PM2.5. Previously, we simply calculated the PM2.5 emitted from the exhaust pipe. If we look at this problem from the perspective of the entire atmospheric environment, the emissions in the exhaust gas still have secondary conversion. Situation, for example, nitrogen oxide compounds will gradually be converted into PM2.5, aggravating the formation of haze.
It can be seen that only by continuously improving the testing standards of conventional pollutants, can environmental pollution be further controlled. Although, in the eyes of many engineers and R&D institutions, there is still a lot of room for improvement in the efficiency of internal combustion engines, but it is obvious that the combination with electric technology can continue its longer life cycle.