As we all know, 5 years ago, the domestic engine was unmatched in terms of power and fuel consumption compared with the joint venture engine. However, with the layout of domestic brands in the field of hybridization in the past two years, China has instantly produced a large number of hybrid engines with thermal efficiency that are proud of the world, such as BYD DM-i's dedicated 1.5L Snap Cloud engine, and the thermal efficiency has reached a staggering 43%, completely abandoning the Japanese "Shuangtian" hybrid engine, which was previously known for its 41% thermal efficiency! This makes people wonder, why did Chinese brands suddenly achieve cornering overtaking in the field of hybrid engines?
Volkswagen EA211evo
First of all, one of the reasons why China's mass-produced engines can achieve curve overtaking in the field of engine thermal efficiency "instantaneously" and lead the world is that there are indeed very few competitors in this field. This is mainly because the thermal efficiency of the engine is higher, the lower the peak power of the engine. At this time, if there is no hybrid system to make up for the lack of power through the combination of batteries and motors, the power performance of the vehicle will be very crotch-pulling. This is certainly unacceptable to European automakers who have formed alliances and are bent on 48V "light mixing", after all, the 48V "light mix" motor can only bring a slight power increase of more than 10 horsepower, which is simply not enough to offset the large loss of horsepower caused by the engine's pursuit of top thermal efficiency. Therefore, this also leads to European manufacturers dare not make the thermal efficiency of the engine too high, such as Volkswagen with 48V light mix system 1.5T EA211evo new engine, its thermal efficiency is only 37.5%.
In other words, the light mixing and plug-in mixing systems of European car companies are basically based on the existing pure fuel engines, achieved by increasing the motor, and have not been redesigned for the engine. As for the 41% ultra-high thermal efficiency 1.5T engine designed by Volkswagen for the DHT hybrid system, it is only in the PPT stage and has not yet been officially mass-produced.
Chevrolet Volt
Unlike European car companies, in the United States, where Hollywood stars each have a Toyota Prius to promote environmentalism, GM Group launched a hybrid model that can achieve series parallel Chevrolet Volt as early as 2010. Since the power of the driving vehicle has changed from the original single gasoline engine to the power combination of a high-power electric motor and a gasoline engine, the 1.5L engine on the Volt can safely and boldly specialize in thermal efficiency, retaining only the peak power of 101 horsepower. Unfortunately, due to the relatively early launch of Volt, the technology to improve thermal efficiency at that time was not rich and mature enough, so even the second-generation Volt model released in 2016, its engine only achieved the highest thermal efficiency of 36.5%.
"Batman" Ben Affleck's car
But with the rise of Tesla in recent years, American Hollywood stars have begun to favor teslas as a symbol of their support for environmentalism. After all, compared with the Prius and Chevrolet Volt, which have no performance to speak of, and have to refuel the hybrid car, the choice of Tesla will not only not be "environmentally friendly" by the duty, but also have strong performance and smarter driving assistance. Therefore, the Chevrolet Volt, which has little marketing, was officially discontinued in 2019, and since then, the US car companies have not launched decent hybrid vehicles, but have fully embraced the general trend of electric vehicles.
After Europe and the United States have abandoned the strong hybrid route, in addition to Japan, which has extremely scarce oil resources, only China, which is equally scarce in oil resources, is left with crazy hybrid vehicle skill points. Among the current Japanese car companies, Toyota, Honda, and Nissan all have high-thermal efficiency engines for hybrid vehicles. Among them, the most thermally efficient is the hybrid Xuanyi e-power built by Nissan for the Chinese market last year. Because hybrid Xuanyi adopts the idea of extended range hybridization, its 1.2L three-cylinder engine is only responsible for generating electricity, so the maximum thermal efficiency is increased to 43% without scruples. As for the hybrid engine of the "Two Fields", everyone should be familiar with it, toyota's 2.5L engine used in the hybrid Camry and Highlander has a maximum thermal efficiency of 41%; the 2.0L LFB11 engine on the Honda Accord hybrid has a maximum thermal efficiency of 40.6%. Since both engines have participating in the drive, thermal efficiency is not as exaggerated as Nissan's.
In summary, it can be found that European car companies have not worked the high thermal efficiency engine exclusive to hybrid models due to the group's firm 48V light mixing route. In the United States, because the family car and hybrid car market has long been swallowed up by Japanese cars, American automakers are still eating the historical dividends of large-displacement self-priming engines on the one hand, and on the other hand, they have begun to skip hybrid vehicles and bet on electric vehicles. Therefore, at present, there are engineers on the earth who have the ability to develop hybrid engines, and have a large enough market to consume hybrid vehicles, only China and Japan are left. The equivalent of the global hybrid camp can already be reduced to China (BYD + Geely + Great Wall + Changan + Chery + SAIC) vs Japan (Toyota + Honda + Nissan). As for the excellent automotive R&D engineers in other countries, their minds are not on the hybrid engine at all, which is equivalent to the hybrid engine, there are few cars participating in the track, so as long as you can surpass the competitors around you, you can basically stand on the "podium".
Seeing this, everyone will definitely be curious, since there are so few competitors for hybrid engines and so many opportunities for overtaking in curves, why didn't domestic automakers launch high-thermal efficiency engines for hybrid vehicles earlier, and had to rush to launch them in the last two years? The reason is actually very simple, because the previous domestic brands did not even have a decent hybrid system, so even if they built a high thermal efficiency engine, it was useless. It should be known that there are only two schemes in the field of hybridization, one is a hybrid system composed of a planetary gear group structure, which is Toyota's own patent and is widely used in the hybrid vehicles within the Toyota Group. The other is a dual-motor series parallel structure hybrid system with clutch, which is currently based on the Honda i-MMD, BYD DM-i, and Great Wall/Chery DHT hybrid.
Honda i-MMD hybrid
The reason why the domestic brand failed to launch a dual motor series parallel structure hybrid system with a clutch in the early years is actually because this hybrid structure patent did not expire until 2019... However, this time, domestic auto manufacturers rushed to the top after the expiration of the patent, not because this structure is bullish and can finally be copied, but because the structure is very simple, as early as 1999, it was preemptively registered by an American company that sold patents for a living. "Patent company" everyone understands that after registration, it is naturally used to collect protection fees, and it is said that a certain field was launched in 2013 because of the payment of "protection fees". Perhaps seeing the success of the Honda i-MMD, domestic brands also began to develop based on this hybrid structure, and waited until 2019 after the expiration of the internationally recognized "20-year patent term" before releasing the "similarity" hybrid.
The reason why the hybrid of this dual-motor series parallel structure is fuel-efficient is because the engine will only generate electricity at the highest thermal efficiency point at medium and low speeds, and the task of driving the vehicle is completed by the motor, so that the engine avoids the inefficient working range of the previous medium and low speed direct drive wheels. At high speed, the engine can be directly connected to the wheel through the clutch, thereby avoiding high-speed conditions that are not conducive to the energy consumption of the motor. At this point, on the basis of efficient hybridization, domestic automobile manufacturers only need to create a high thermal efficiency engine for this hybrid system to achieve ultra-low fuel consumption.
If crops want to grow well, in addition to the internal factors of land, seeds, and people taking care of them, the external factor of good or bad weather is also the key to determining whether the final grain can be harvested. This is like the domestic hybrid model made out, the initial consumer probability can not understand the hybrid than the pure fuel car more expensive than the tens of thousands of pieces of the difference in meaning, so that the manufacturer does not dare to vigorously pave the hybrid, for fear of the price difference more expensive than the pure fuel car, will lead to brand sales on the street. In this way, consumers pay the bill, manufacturers will invest profits in research and development again to enhance competitiveness, and consumers can not use the same price to buy better products of industrial product upgrading cycle at all. Fortunately, the big hand of the mainland policy is just stuck at the time point before the domestic manufacturers have launched hybrid models, and the introduction of the policy has paved the way for hybrid vehicles and electric vehicles, which has played a role in fueling the waves!
In April 2018, the mainland introduced a strict double credit policy, which calculates points based on the fuel consumption of vehicles sold by enterprises every year, and if the fuel consumption of vehicles is too high, the company's points will become negative, and then need to pay fines or even be forced to delist. If you sell more hybrid vehicles and new energy vehicles, you can obtain positive points, which can not only offset the negative points of other high-fuel-consuming fuel vehicles to a certain extent, but also sell the points to other car companies to earn considerable income. For example, for every pure electric vehicle with a range of 500km, a car company can get 6.8 points, and selling a plug-in hybrid can obtain 2 points. Taking BYD as an example, in 2020, BYD obtained nearly 750,000 positive points for new energy by selling new energy vehicles, and the market price of one point at that time could be sold to 3,000 yuan, which is equivalent to if BYD sold all the points, it could make a profit of about 2.25 billion yuan! Although it is not known how much money BYD actually made by selling points, according to BYD's corporate annual report, BYD's corporate net profit in 2019 was only 1.614 billion, and in 2020, the corporate net profit reached 4.234 billion. Therefore, for car companies surviving in China, reducing fuel consumption of fuel vehicles and producing more plug-in hybrid and pure trams has become a decision that must be made.
In addition to the "strong push" of the double integral policy, the lottery purchase restriction policy implemented by major cities in China in the past ten years is also a booster for the rapid development of domestic plug-in and mixed vehicles. After all, the plug-in mixed car can enjoy a lottery-free and free license policy in most cities except Beijing, while there is no anxiety about the endurance of electric vehicles. Therefore, although in the past few years, the domestic plug-in mixed car has no blessing of the strong hybrid system, and the fuel consumption without charging is frighteningly high, there are still many consumers who will choose to buy a plug-in mixed car under the preferential treatment of the policy to enjoy the policy benefits.
The power of the policy is strong, the time point of the expiration of the hybrid patent is just right, and the Chinese car companies are also competing for gas, after a short period of inefficient plug-in hybrid chaos, the domestic efficient hybrid system officially ushered in the blowout period. At the end of 2020, BYD took the lead in launching the DM-i efficient plug-and-mix system, and relied on the inherent advantages of the plug-and-mix policy, excellent smoothness, and the loss of electricity and fuel consumption comparable to the "two fields" hybrid vehicle, which quickly won the pursuit of consumers, and then the Great Wall also launched a SIMILAR structure OFT system. Geely launched the DHT Pro system that added a 3-speed transmission last year, and its hybrid structure and working logic are superb, even the Japanese "two fields" have to be ashamed of themselves.
Seeing this, everyone will certainly be curious, for China's hybrid, patent expiration, policy push at best is considered to be the time, location, that person and this piece, how do Chinese manufacturers catch up in the field of hybrid engines that are indispensable to the hybrid system? Below I will bring you the highlight of this article, that is, why China can achieve cornering overtaking in the field of hybrid engines in an instant!
For a long time, the reason why the gasoline engines of domestic manufacturers cannot be compared with the joint venture manufacturers is mainly because the engines used solely for fuel vehicles must take into account both power, fuel consumption, cost, technology, and development time, so it is indeed very difficult to build. The most difficult of these is the balance between power and fuel consumption, because it not only requires high research and development costs, but also requires a long period of accumulation in the field of engines. After all, looking back at history, a good engine is usually piled up by accumulating technology for a long time, and the hero in the network cool article turned out to be born, and the storyline that directly creates miracles is difficult to appear in the field of engine manufacturing.
Nissan HR16 engine
A good example is the Nissan HR16 1.6L naturally aspirated engine, which has little sense of existence. This engine was first born in 2006 and has served many entry-level models such as Xuanyi, Qida, Jinke and Sunshine in the past decade. The 1.6L self-priming engine's Bull X is that in the 16 years since its development to the 3rd generation, Nissan has only upgraded some details to keep the engine's power and fuel consumption ability at the top level for a long time.
Nissan cylinder wall melt injection process
For example, the second generation of HR16 has been upgraded from the original variable valve timing to continuous variable valve timing, and the third generation has been upgraded to e-VTC intelligent electric continuous variable valve timing, and the upgrade of this gas distribution structure provides a good foundation for reducing fuel consumption and improving power. In addition, the third generation of HR16 engine also canceled the cylinder liner design and upgraded to the same cylinder wall melt injection process as the GT-R engine, which can effectively reduce the resistance of piston operation. And on this basis, Nissan has improved the fuel economy of the engine by improving the compression ratio, and finally increased the peak horsepower of the HR16 engine from 109 horsepower of the original generation to 139 horsepower of the third generation, and with the upgrading of the engine, the fuel consumption of Xuanyi NEDC has also dropped from 7.2L/100km of the first model to 4.9L/100km of the third-generation model, achieving a double increase in power and fuel consumption.
Since engine manufacturing is so emphasis on technology accumulation, why can domestic cars achieve curve overtaking in the field of hybrid engines in an instant?
Through the evolution of the Nissan HR16 engine above, it is not difficult to find that it is indeed not possible to create an engine that takes into account both power and fuel consumption overnight. But! As long as we erase the need for either of the two indicators of fuel consumption and power, the engine will be much better. For example, the reason why the modification factory can easily increase the engine power significantly through the brush program is because they have abandoned the requirement that the original engine must take into account fuel consumption emissions when designing. On the contrary, if you give up the power and only grasp the fuel saving, it is also easy to make the thermal efficiency of the engine high. It just so happens that the engine on the hybrid car plays the role of a range extender for most of the time, and it does not need any power, so like the current BYD Tang DM-i 1.5T engine, it only has 139 horsepower; the Honda i-MMD's 2.0L engine is only 146 horsepower.
The reason why the series parallel hybrid system does not need to consider the engine power is mainly because its operation mode does not depend on the power of the engine. As mentioned above, when the vehicle is in the tandem mode at medium and low speed, the engine will only play a role in generating electricity, and the driving force of the wheel is provided by the driving motor, which means that the power of the engine will not affect the acceleration performance of the vehicle, and the power only needs to meet the power consumption of the motor. In high-speed parallel mode, although the power source of the vehicle to maintain the cruising state is switched to the engine, it does not require much power to maintain the vehicle's cruising. For example, for an ordinary family compact sedan for cruising at a speed of 120 km/h, about 35 horsepower is enough. Therefore, a model like the 1.5L hybrid Atom, even if the peak horsepower of the engine is only 109 horsepower, can fully meet the cruising power requirements of the vehicle. In the case of high-speed overtaking conditions that require strong power output, the hybridization of this series-parallel structure can also mobilize the drive motor with more horsepower than the engine to accelerate with the engine. In this way, because the whole working condition does not require the engine to exert great force, the hybrid engine can give up power and pursue thermal efficiency.
After understanding why a series-parallel hybrid engine doesn't need power, we can understand why a thermally efficient engine that doesn't need to think about power is a good build. One of the most critical reasons is that the development of a hybrid engine only needs to make the thermal efficiency of one "point" high. Ordinary fuel engines need to take into account thermal efficiency and power in the entire "surface" range. For example, the above figure is the "brake ratio fuel consumption graph" of the Honda 2.0 hybrid engine (left) and the 1.5T supercharged engine (right), and the number on the medium and high lines represents how many grams of gasoline per kilowatt of power per kilowatt of power consumed by the engine in the current speed and torque output state, and the smaller the number of an area or point, the higher the thermal efficiency and fuel saving of the engine.
Still taking this figure as an example, we can see that the most fuel-efficient area on the 2.0L self-priming engine specially built for hybrid vehicles on the left is 210g/(kW·h), while the most fuel-efficient area of the 1.5T turbine used in the pure fuel vehicle on the right is 240g/(kW·h), which is equivalent to 30g more fuel consumption per hour per kW of power than the hybrid 2.0L self-priming. However, from the comparison chart, we can also see that the 240g/(kW·h) working area of the 1.5T engine is much larger than the 210g/(kW·h) working area of the most fuel-efficient 2.0L hybrid engine, which means that although the 1.5T does not have 2.0L self-priming and fuel saving in a small working range, it can cover a wider area with its own 240g/(kW·h) optimal fuel consumption with stronger torque. This is the difference between taking into account the thermal efficiency of only one "point" and taking into account the thermal efficiency and power on a "surface".
You know, if you want to make a pure fuel engine in a large range to take into account the power and fuel consumption, that is, to make the "surface" bigger, it is necessary to adjust the gas distribution, ignition timing, fuel injection volume, and even the starting state of the turbine under all working conditions of the engine to the extreme, which not only requires a lot of hardware, time cost, but also inseparable from the strong engine research and development capabilities of the car company, if there is no long-term technical accumulation is impossible to do.
But if you change to a hybrid special engine that only needs to meet the needs of motor drive and only needs to make a "point" thermal efficiency high, the difficulty is much lower. For example, at the hardware level, because no power is required, hybrid engines can first be used on conventional fuel engines that reduce power but improve thermal efficiency in the Atkinson cycle to avoid pump air loss at low loads. Secondly, the hybrid engine can also greatly improve the compression ratio and the air-fuel ratio to make the engine achieve the effect of thin combustion, and further improve the thermal efficiency of the engine.
BYD 1.5L Snap Cloud engine
Not only that, because the hybrid engine usually only generates electricity within a small range of speed fluctuations, it is not necessary to assemble the valve lift function that adapts to the high and low speed, so the gas distribution mechanism can also be omitted, while saving costs, it also reduces the operating resistance of the gas distribution mechanism, which is also helpful for thermal efficiency, such as BYD's 1.5L Xiaoyun engine cancels the valve adjustment mechanism on the exhaust valve side. In terms of tuning, because the hybrid engine working condition is very single, and the structure is simple, it does not require the manufacturer to have strong tuning ability and experience.
In summary, it is not difficult to find that creating a fuel-saving hybrid engine is indeed much simpler than building a traditional fuel vehicle engine that takes into account both power and fuel consumption.
Nowadays, the implementation of the strict emission standards of China VIB has forced many car companies to meet emission policies by developing new engines and installing particle traps. It should be known that the current emission difficulties of gasoline engines are mainly caused by the nitrogen oxides generated by insufficient combustion of oil and gas mixtures at low speed and low load of vehicles. However, due to the single operating condition of the parallel hybrid engine, and the maximum thermal efficiency point of about 2000 rpm will be at a single working point, the engine will not have a low load condition that is not conducive to combustion, and it will become a breeze to pass the emission regulations. And from the current point of view, the engine on the hybrid model, whether it is self-priming or turbocharging, because its daily working conditions are very healthy, so almost no need to install particle traps on the exhaust.
In addition, because the three-way catalyst responsible for filtering the exhaust gas can only provide the best purification capacity at an air-fuel ratio of 14.7:1, and the acceleration and deceleration conditions of ordinary fuel vehicles will cause fluctuations in the engine air-fuel ratio, so it is easy to cause excessive emissions of exhaust pollutants. For models with series-parallel hybrid systems, first of all, as mentioned earlier, the output power of the engine in most working conditions is fixed, and the air-fuel ratio of 14.7:1 can be maintained very stable. Secondly, if you encounter an acceleration condition that requires the engine and the drive motor to exert force at the same time, the drive motor will also give priority to adjusting the output power to avoid large load changes in the engine, thereby maintaining the stability of the air-fuel ratio and avoiding excessive exhaust pollutant emissions. Therefore, hybrid models can not only easily pass the current strict National 6B, but even if the future National 7 emissions continue to increase, hybrid models can still sit back and relax.
Since the hybrid engine and the pure gasoline engine use a completely different design idea, so at the end of this article we may wish to make a hypothesis, if these thermally efficient hybrid engines are installed in the cabin of the pure fuel vehicle, then what will it feel like to drive this pure fuel vehicle?
First, the poor peak power of the high thermal efficiency engine will cause the power of the car to be very crotch-pulling. Secondly, due to the narrow range of high thermal efficiency of hybrid engines, when pure fuel vehicle engines are used, fuel consumption will become very high. Finally, because the highest thermal efficiency of the hybrid engine is generally around 2000 rpm, if the automatic model matches each gear to an efficient 2000 rpm according to the fuel-saving logic, the car will drive every day because of the high engine speed, and there will be noise annoyance problems.
If a person pops up 10 years ago, he will open up to the public: in less than 10 years, China's car manufacturing level will be raised to the same high level as the first echelon level in Europe, the United States and Japan! Then this person is most likely to be treated as a "little pink". But today, 10 years later, whether it is in the field of electric vehicles that represent the future, or in the field of hybrid vehicles that assume a transitional role and have a driving experience that far exceeds that of pure fuel vehicles, several models in China have completed the real sense of "curve overtaking". At this time, if you ask me what level China's car manufacturing will develop in the next 10 years, I am not good to say, nor dare to say, because I am afraid that everyone will read my predictions and will also put me in the ranks of "little pink". But what I can be sure of is that with the official announcement of the suspension of pure fuel vehicles by BYD on April 3, 2022, there will be more and more Chinese brands that stop production of pure fuel vehicles in China in the future, because now everyone has made sufficient preparations and is ready for the next 10 years, the highlight moment that belongs to China's car manufacturing.