Yu Hexin also knew that the big boss of Huaxing Group Company in front of him was from a technical background, so he also discussed with Yang Jie about the ultra-lean combustion engine.

"Zhongyuan Automobile Group Co., Ltd. and Mazda have overlapped many parts of the conceptual technical route of ultra-lean combustion, similar to the thinner degree of diesel engines, but how much is the most appropriate degree of thinness, the technical teams of both companies have done a lot of research, and they all believe that it is most appropriate to increase the air-fuel ratio to more than 2 times the theoretical air-fuel ratio. ”

Yang Jie said with a smile.

"The limit value of the spark plug ignition mixture is only 1.35, and you have to achieve an excess air coefficient of more than 2, which is not possible with conventional car igniters. ”

Yu Hexin looked at Yang Jie and said, "No wonder your Huaxing Group has been developing technology for microwave igniters. ”

"The ignition of the microwave igniter is hundreds of times the volume of the spark plug, the temperature is 1200 degrees, the microwave energy emitted can be confined in the cylinder, and the microwave electromagnetic field can change the chemical reaction of fuel combustion, these carbohydrates will be cleaved, thus triggering a series of free radical chain reactions, we have done a lot of experiments, and it has been proved that the content of harmful pollutants has indeed been reduced by a small margin. ”

Yang Jie said with a smile: "We have been researching this area for more than five years, and now we have finally seen the results, and this technology can at least extend the service life of internal combustion engine technology for another one or two decades." ”

In fact, the reason why Huaxing Group has been able to achieve results in this area is mainly because Huaxing Group has made great progress in microwave technology and gallium nitride power devices.

Microwave igniters have not been studied abroad before, Eagle Sauce's West Virginia University has done a series of research on microwave igniters, and in 2001 they made a microwave igniter with a resonant frequency of 2.45GHz, but it was not very successful.

Later, Huaxing Group also encountered a lot of problems when developing microwave igniters, mainly the design of microwave resonators and the modulation of microwave energy.

The geometric size of the resonator largely determines the size of its Q value, the larger the size, the more energy storage of the resonator, but when the size of the resonator is too large, it also brings a large ohmic impedance loss on the inner surface of the cavity and the radiation loss at the top opening, and when the resonator has the maximum Q value, it cannot make the tip of the inner conductor form the maximum electric field, because the small diameter of the inner conductor is easier to excite the tip of the strong electric field, so how to choose the resonator is a very test of the designer's skills.

Huaxing Group also selected a suitable coupling design scheme after designing a variety of schemes through a large number of electromagnetic simulations.

Because the choice of a suitable coupling method not only ensures the performance of the resonator, but also takes into account the simplicity of the integrated machining method.

In addition, considering that this resonant cavity is to be plugged into the inside of the engine block, it is impossible to make it much larger than the spark plug, which puts forward very high requirements for the power of the input microwave, the microwave power must reach 400 watts, the electric field strength of the top of the conductor in the resonant cavity can reach the threshold condition of excitation plasma flame, with the increase of power, the electric field is also enhanced, and the breakdown area is correspondingly larger.

At the beginning, Huaxing Group could only make a 20-watt monolithic gallium nitride power microwave integrated circuit, but now Huaxing Group has been able to make a single 200-watt chip, because of the use of more advanced process technology, so the packaging chip is smaller, and the microwave power can be output through the power synthesizer, and the product size is only the size of a cigarette box, and the original chip needs to be the size of a toolbox, and the volume is still relatively large.

Of course, this is due to the fact that Huaxing Group's technology in gallium nitride power devices has also gone further, and the cost of chips has also decreased significantly with the progress of gallium nitride wafer preparation technology, which also allows microwave igniters to begin to be used in automotive ignition systems.

In the past, this igniter device could not be stuffed into a car because it was too large and very expensive.

This microwave ignition device is actually equivalent to stuffing a microwave oven into the cylinder for ignition heating, and the frequency of the resonator is deliberately adjusted to 2.45G hertz because the resonance frequency of fuel hydrocarbons is at this frequency.

To do this step is also a huge engineering and technical challenge for Huaxing Group Company, but fortunately, the overall technical strength of Huaxing Group Company is improving every year, more than five years, the technical department of Zhongyuan Automobile Group Company through a large number of research and development, continuous improvement, and now this set of igniters is used in the development of ultra-lean combustion engine.

Yu Hexin couldn't sit still at this time, so he took Chen Fangtong and Yang Jie and others to visit the powertrain R&D center of Zhongyuan Automobile Group.

Yu Hexin also saw two generations of prototypes of this microwave igniter in the sample display area, the size of the first generation is larger than the size of the microwave oven, and the size of the second generation is only the size of a DVD player, and the third generation is not displayed because it is still in the test.

Subsequently, Yu Hexin and others also saw the prototype of the ultra-lean combustion engine that was being tested on the test bench for various experiments.

This is a four-cylinder engine, a 2.0L inline four-cylinder naturally aspirated in-cylinder direct injection engine, very small in size, and the cylinder block is cast in aluminum alloy.

Yu Hexin also noticed at this time that the microwave igniter near the engine was only the size of a pencil case, and four microwave tubes were connected at the same time, which were also connected to the location of the engine's spark plug.

Hong Lei also proudly introduced this engine at this time, "This is also the first naturally aspirated ultra-lean combustion engine jointly developed by us and Mazda's technical department, and we have also applied a large number of new technologies, judging from the current experimental data, the performance of this engine even exceeds our design goals......

Yu Hexin looked at the technical experts from Mazda at this time, and these experts also had smiles on their faces at this time, obviously very proud of their participation in the joint development of such an engine.

In order to achieve the Otto cycle with a compression ratio of 13 in the high load area, Zhongyuan Automobile Group has also introduced an electric valve phase regulator device, which relies on the motor to control the valve phase, avoid the drawbacks of the hydraulic adjustment system, and can quickly and stably control the valve angle.

When Yu Hexin heard Hong Lei mention that this electric valve phase adjuster also uses a planetary gear reducer, which can quickly and accurately control the timing of the intake camshaft and realize complex engine cycle mode switching, and this device is also designed and developed by Zhongyuan Automobile Group Corporation.

Yu Hexin was also very emotional at this time: not to mention anything else, just such an electric valve phase regulator condensed the hard work of many engineers of Zhongyuan Automobile Group and Huaxing Group Group bit by bit.

At this time, a feeling of shame arose in his heart.