“Toyota “”Hydrogen Engine Vehicle”” Aimed for Commercialization! Corolla & Corolla Cross”” Prototype Unveiled! Trying Liquid Hydrogen!
Toyota’s Idea of a Hydrogen Engine
At the “”Super Taikyu Series Round 2 Fuji 24 Hour Race”” to be held from June 3 to 5, 2022, Toyota has announced that it will launch a hydrogen engine vehicle, which has been under development for some time.
What kind of development is underway?
See the actual “”Corolla Cross,”” an awesome car unveiled for the first time in the world!
Toyota has stated that it will bring a “”hydrogen engine vehicle”” to market! (Image: The Corolla (liquid hydrogen version) equipped with a hydrogen engine that was unveiled to the public)
One year after the 2021 S-Taiji 24 Hour Endurance Race, the grown-up hydrogen engine is back.
We have reported in the news about the car that it has grown a great deal in just one year, but perhaps the easiest way to understand this is in the lap times.
In 2021, the lap time was 2 minutes 4.059 seconds (fastest lap in the race), while in 2022 it was 1 minute 58.868 seconds (qualifying), a reduction of almost 6 seconds.
Furthermore, the time required for the water supply was also greatly reduced, from more than 6 minutes in 2021 to 1.5 minutes in 2022.
The biggest reason for the success of the unknown engine in just one year is Toyota’s practice of “”creating better cars with motor sports as the starting point.
Toyota calls it agile development, and they have changed the way we work by “”making deadlines clear”” and “”evaluating in a place where everyone is watching.
As a result, the up-front development process, which has been difficult to see, can now proceed with a greater sense of speed.
Nevertheless, hydrogen engines are not without their challenges. One of them is the cruising range.
Although fuel efficiency has been improved by improving the combustion efficiency of the engine, the cruising range is calculated by multiplying the fuel efficiency by the tank capacity.
Currently, the hydrogen fuel used in hydrogen engines is a gas, so there is a limit to the amount of hydrogen that can be installed.
One way to solve this problem is to mount hydrogen in “”liquid”” form.
This is easy to say in words, but hydrogen becomes a liquid at -253 degrees Celsius, so it is not as easy to use as gasoline.
However, “”it is necessary to take up the challenge for practical use,”” and at the final round of the S-Taiyu (Okayama) last year, GR President Tsuneji Sato announced that “”we will begin the technical challenge to switch the fuel from gaseous hydrogen to liquid hydrogen.
However, everyone knows how high the hurdle is, so I also knew that it would not be so easy.
However, Toyota has gone above and beyond. To my surprise, they unveiled a hydrogen Corolla (based on the GR Corolla) that uses liquid hydrogen.
When we asked President Akio Toyoda about this, he replied, “”We really wanted to debut it here (at the 2022 Fuji 24-hour endurance race), but as expected, there was not enough time. It is such a difficult technology.
However, to have come this far in only about six months since the announcement in Okayama, this is the speed of today’s Toyota.
In addition to the vehicle exhibit, the system from the tanker truck carrying liquid hydrogen to the fuel supply system is also on display.
The surprising thing is the size of the system, which was displayed next to a mobile hydrogen station that supplies gaseous hydrogen for comparison, and it is an extremely compact design. This would make it possible to install the system in a pit.
I was looking at it with admiration, thinking, “”This is amazing! While I was admiring the exhibit, an engineer came up to me.
He is Mr. Naoaki Ito, who is in charge of the hydrogen engine project. Mr. Ito is an expert who has mainly worked on “”special models”” in a sense, such as the Lexus “”LF-A””, “”LFA””, the experimental vehicle “”LFA Code X””, and the hydrogen engine Corolla, and is naturally also involved in the liquefied hydrogen project. We asked him to answer a variety of questions.
–Six months after Okayama, I was surprised to see how far development had progressed.
Unfortunately, we didn’t make it in time for the 24-hour period, but we have reached this point with the infrastructure and the car connected.
– but it runs, right?
It’s really a brand-new car, so we haven’t run it yet.
What we have unveiled in this situation is “”making friends.
Even for us, we are still in the learning stage, but we want to do it with all-Japan technology.
However, there are really only a few companies and organizations that are working on liquid hydrogen, so by unveiling the technology at an early stage, we are asking, “”Why don’t we do this together?”” And.
–The hydrogen engine Corolla has improved considerably over the past year. I was also given a ride in a GR Yaris development vehicle, and I felt that the responsiveness, response, and torque production were superior to gasoline-powered vehicles in many respects.
However, the issue is the cruising range. One way to solve this problem is to use liquid hydrogen.
–Is liquid hydrogen still better?
People ask me, “”Which is better, liquid or gas?”” But each has its own advantages, so it is important to be able to make a choice.
For example, gaseous hydrogen is better for a car that is used for a short trip to the store, while liquid hydrogen is better for a car that is used for commercial purposes, or a car that is high performance and uses a lot of fuel.
–What difference does the use of liquid hydrogen fuel make on the engine side?
We want to use the same fuel regardless of whether it is gas or liquid. It depends on the application/size of the vehicle.
–I think the key will be the fuel tank that holds the liquid hydrogen, but are there still many technical challenges?
There are many hurdles to overcome in terms of “”putting it in a car. To begin with, there are very few manufacturers that make liquid hydrogen tanks, so we are taking on this challenge together with our partner companies.
Currently, the size is quite large, but as the technology advances, it will become even more compact.
As the technology advances, the size of the tank will become even more compact, and since the amount of hydrogen installed will increase, the cruising range will approach that of gasoline-powered cars. ……
Toyota “”Hydrogen Engine Vehicle”” Aiming for Commercialization! Corolla & Corolla Cross”” prototypes unveiled! Tackling Liquid Hydrogen!
What Will Be the Challenges of Liquid Hydrogen Technology?
–This year’s exhibit also includes a liquid hydrogen carrier. What are the applications for this?
This vehicle is the largest one and is usually used for the space rocket at Tanegashima.
It is about twice the size of a hydrogen truck that delivers hydrogen to a hydrogen station in the city.
–Is liquid hydrogen used to transport the hydrogen to the hydrogen station?
Hydrogen transported in liquid form is vaporized, pressurized with a pump, and filled into the MIRAI.
If the technology for in-vehicle liquid hydrogen tanks becomes a reality, we can simply fill MIRAI with hydrogen brought in in liquid form.
–A system for supplying hydrogen is also on display, but it is considerably more compact than the gaseous system.
This system is being developed exclusively for racing, and the reason for its rather thin design is that it is intended to be placed in the pit.
The space used is about 1/4 of the space currently expected to be used.
The reason we put it next to the gas feedwater element system this time is that it will be so much more compact. With this system, it is possible to use the feedwater element on pit road just like gasoline.
Hydrogen Corolla (liquid hydrogen specification)”” unit
–The quick charger that fills the tank with liquid fuel has different pipe thicknesses for the filling port and the return side. Normally, the filling port would be thicker, but this one is thicker on the return side, isn’t it?
The fill port is liquid and has a high energy density, so this thickness is fine. Conversely, the return side is a gas, so its volume is larger, so thicker piping is used.
The fuel supply pipe also has a thermos bottle structure to prevent heat from entering the fuel supply pipe, which would otherwise vaporize.
The moment it turns from a liquid to a gas, it expands 800 times, so it must be carefully controlled.
–What is particularly difficult about using liquid hydrogen?
Everything (laughs), but the development of the liquid hydrogen pump, which acts as a fuel pump for gasoline-powered cars.
This is where fuel pressure is created and sent to the engine side. In liquid form, it cannot be blown by the injectors, so it is converted to gas using a carburetor.
Incidentally, this carburetor utilizes heat from the engine. I think we can also manage the total heat management of the car well.
–By the way, what is the pressure chamber above the fuel tank used for?
The pump cannot keep up with a sudden increase in fuel consumption, so the fuel is stored in the chamber to cope with sudden changes in the accelerator pedal.
–What is this component called a boil-off valve?
Liquid hydrogen is gradually vaporized by heat from outside the tank.
This is called “”boil-off gas,”” and as it increases, the pressure becomes higher and higher, so it needs to be released.
However, it cannot be released as it is, so it is turned into “”water”” through a catalyst and released.
In this way, we have taken precautions against “”dangerous”” parts of the system. However, since race cars run at full throttle, there is basically no boil-off, but it is for standby in the pits.
–Speaking of liquefied hydrogen, BMW has also been developing it in the past.
Their engines used port injection, but ours use direct injection.
We use direct injection, which requires a liquefied hydrogen pump because of the high fuel pressure. In that sense, it is the same liquefied hydrogen, but the concept is different.
–What about the cruising range? How much longer is it compared to gaseous hydrogen?
It is about twice the range of gaseous hydrogen at this size. In the future, we would like to install an even larger size while confirming safety, but for now, we are trying to get it running.
Toyota “”Hydrogen Engine Vehicle”” Aimed for Commercialization! Corolla & Corolla Cross”” Prototype Unveiled! Trying Liquid Hydrogen!
We’ve moved “”toward commercialization””… but how many stations would you compare it to on Mt. Fuji?
What you may be wondering about is the mass production part.
Fuji,”” titled “”Toward Commercialization”” and “”The Road to Water Supply Elements. Fuji. The contents of the presentation are as follows.
Toward commercialization
First stage: fuel development and elemental technology development
2nd stage: Performance development and functional reliability issues
3rd stage: fuel efficiency development
Phase 4: Emission development
5th – Functional reliability/measures
Downsizing of tank
Stage 7 Demonstration and Evaluation
Drivability Development
Stage 9: NV development
Movement toward commercialization of hydrogen engines
Hydrogen feed-water element road
1st station: Water supply element practice and testing
2nd stage – Increasing the pressure boosting rate
3rd station Twin filling
4th station Higher flow rate
5th station – Running-in to liquid
Stop 6 Downsizing the system
Stop 7 Reliability
Stop 8 Demonstration and Evaluation
Stage 9: Market adaptation/improvement
* * * * *
When I asked President Sato of GR, he said, “”Currently, it is about 40% …….
This also has a meaning. Fuji is relatively easy to climb up to the 5th station, but after that, the hurdle rises dramatically.
In other words, the road ahead is never smooth. However, we are sure that the summit is in sight, and we just have to move forward steadily, step by step,”” he said.
However, this announcement does not mean that gaseous hydrogen will be replaced by liquid hydrogen.
They will continue to develop both in parallel. In other words, they are “”giving hydrogen a choice. I am looking forward to the future again.
Translated with www.DeepL.com/Translator (free version)”
