- What is a hydrogen engine?
- Short story
- How does work
- Hydrogen engine types
- How long is the service life of fuel cells?
- Which companies are already making or are going to make hydrogen cars?
- How much does a hydrogen-powered car cost?
- Why are hydrogen cars better than electric cars?
- What are the prospects for hydrogen cars and when will they be seen on the road?
- Pros and main disadvantages of hydrogen engines
Internal combustion engines did not appear as separate power units dramatically. Rather, the classic motor came about as a result of the refinement and improvement of heat engines. Read about how the unit, which we are used to seeing under the hood of cars, gradually appeared. in a separate article.
However, when the first car equipped with an internal combustion engine appeared, mankind received a self-propelled vehicle that did not require constant feeding, like a horse. Many things have changed in motors since 1885, but one drawback remains unchanged. During the combustion of a mixture of gasoline (or other fuel) and air, too many harmful substances are released that pollute the environment.
If before the advent of self-propelled vehicles, the architects of European countries feared that large cities would drown in horse dung, today the inhabitants of megacities breathe dirty air.
Tightening environmental standards for transportation are forcing vehicle manufacturers to develop a cleaner powertrain. So, many companies are interested in the previously created technology of Anjos Jedlik - a self-propelled cart on electric traction, which appeared back in 1828. And today this technology has become so firmly established in the automotive world that you will not surprise anyone with an electric car or a hybrid.
But what is really encouraging is the power plants, the only release of which is drinking water. It's a hydrogen engine.
What is a hydrogen engine?
This is a type of engine that uses hydrogen as fuel. The use of this chemical element will reduce the depletion of hydrocarbon resources. The second reason for the interest in such installations is the reduction of environmental pollution.
Depending on what type of motor will be used in transport, its operation will differ from the classic internal combustion engine or be identical.
Hydrogen internal combustion engines appeared in the same period when the ICE principle was being developed and improved. A French engineer and inventor designed his own version of an internal combustion engine. The fuel that he used in his development is hydrogen, which appears as a result of electrolysis of H2A. In 1807, the first hydrogen car appeared.
The power unit was piston, and the ignition in it was due to the formation of a spark in the cylinder. True, the first creation of the inventor needed manual spark generation. After just two years, he finalized his work, and the first self-propelled hydrogen vehicle was born.
However, at that time, development was not given importance, because gas is not as easy to obtain and store as gasoline. Hydrogen motors were practically used in Leningrad during the blockade from the second half of 1941. Although, we must admit that these were not exclusively hydrogen units. These were ordinary GAZ internal combustion engines, only there was no fuel for them, but there was plenty of gas at that time, since they were fueled by balloons.
In the first half of the 80s, many countries, not only European ones, but also America, Russia and Japan undertook to experiment with this type of installations. So, in 1982, with the joint work of the Kvant plant and the RAF automobile enterprise, a combined motor appeared, which ran on a mixture of hydrogen and air, and a 5 kW / h battery was used as an energy source.
Since then, there have been attempts by different countries to introduce "green" vehicles into their model lines, but in most cases such cars either remained in the prototype category or had a very limited edition.
How does work
Since today there are many operating motors of this category, in each individual case the hydrogen plant will operate according to its own principle. Consider how one modification works that can replace the classic internal combustion engine.
In such a motor, fuel cells will definitely be used. They are a kind of generators that activate an electrochemical reaction. Inside the device, hydrogen is oxidized and the reaction results in the release of electricity, water vapor and nitrogen. Carbon dioxide is not emitted in such an installation.
A vehicle based on a similar unit is the same electric vehicle, only the battery in it is much smaller. The fuel cell generates enough energy to operate all vehicle systems. The only caveat is that from the beginning of the process to the generation of energy, it can take about 2 minutes. But the maximum output of the installation begins after the system warms up, which takes from a quarter of an hour to 60 minutes.
So that the power plant does not work in vain, and it is not necessary to prepare the transport for the trip in advance, a conventional battery is installed in it. While driving, it is recharged due to recuperation, and it is needed exclusively for starting a car.
Such a car is equipped with a cylinder of different volumes, into which hydrogen is pumped. Depending on the driving mode, the size of the car and the power of the electrical installation, one kilogram of gas can be enough for 100 kilometers of travel.
Hydrogen engine types
Although there are several modifications of hydrogen engines, they all fall into two types:
- Unit type with fuel cell;
- Modified internal combustion engine, adapted to work on hydrogen.
Let's consider each type separately: what are their features.
Power plants based on hydrogen fuel cells
The fuel cell is based on the principle of a battery, in which an electrochemical process takes place. The only difference between the hydrogen analogue is its higher efficiency (in some cases, more than 45 percent).
The fuel cell is a single chamber in which two elements are placed: the cathode and the anode. Both electrodes are platinum (or palladium) coated. A membrane is located between them. It divides the cavity into two chambers. Oxygen is supplied to the cavity with the cathode, and hydrogen is supplied to the second.
As a result, a chemical reaction occurs, the result of which is the combination of oxygen and hydrogen molecules with the release of electricity. A side effect of the process is water and nitrogen released. The fuel cell electrodes are connected to the car's electrical circuit, including the electric motor.
Hydrogen internal combustion engines
In this case, although the engine is called hydrogen, it has an identical structure as a conventional ICE. The only difference is that it is not gasoline or propane that burns, but hydrogen. If you fill a cylinder with hydrogen, then there is one problem - this gas will reduce the efficiency of a conventional unit by about 60 percent.
Here are a few other problems with switching to hydrogen without upgrading the engine:
- When the HTS is compressed, the gas will enter into a chemical reaction with the metal from which the combustion chamber and piston are made, and often this can also happen with engine oil. Because of this, another compound is formed in the combustion chamber, which is not distinguished by a special ability for high-quality combustion;
- The gaps in the combustion chamber must be perfect. If somewhere the fuel system has at least minimal leakage, the gas will easily ignite upon contact with hot objects.
For these reasons, it is more practical to use hydrogen as a fuel in rotary motors (what is their feature, read here). The intake and exhaust manifolds of such units are located separately from each other, so the gas at the inlet does not heat up. Be that as it may, while the engines are being modernized so as to circumvent the problems of using cheaper and more environmentally friendly fuel.
How long is the service life of fuel cells?
All over the world today, such cars are very rare, and they are not yet in the series, it is difficult to say what resource this energy source has. The craftsmen have no experience in this regard yet.
The only thing that can be said according to the statements of representatives Toyota the fuel cell of their production car Mirai is capable of uninterruptedly generating energy up to 250 thousand kilometers. After this milestone, you need to monitor the effectiveness of the device. If its performance has noticeably decreased, the fuel cell is changed at an authorized service center. True, one should expect that the company will charge a decent amount for this procedure.
Which companies are already making or are going to make hydrogen cars?
Many companies are engaged in the development of an environmentally friendly power unit. Here are the auto brands, in the design bureau of which there are already working options, ready to go into series:
- Mercedes-Benz is a GLC F-Cell crossover, the start of sales of which was announced in 2018, but so far only some enterprises and ministries of Germany have acquired it. A prototype hydrogen fuel cell tractor unit, the GenH2, was recently unveiled;
- Hyundai - Nexo prototype, presented two years ago;
- BMW - a prototype hydrogen Hydrogen 7, which was released from the conveyor. The batch of 100 copies remained in the experimental stage, but this is already something.
Among the stock cars that can be bought both in America and in Europe are the Mirai and Clarity models from Toyota and Honda, respectively. For other companies, this development is still either in the drawing version, or as a non-working prototype.
How much does a hydrogen-powered car cost?
The cost of a hydrogen car is decent. The reason for this is the precious metals that make up the electrodes of fuel cells (palladium or platinum). Also, a modern car is equipped with countless security systems and stabilization of the operation of electrical elements, which also requires material resources.
Although the maintenance of such a car (until the fuel cells are replaced) is not much more expensive than an ordinary car of the latest generations. There are countries that sponsor the production of hydrogen, but even with this, you will have to pay an average of 11 and a half dollars per kilogram of gas. Depending on the type of engine, this can be enough for a distance of about one hundred kilometers.
Why are hydrogen cars better than electric cars?
If you take a hydrogen plant with fuel cells, then such a car will be identical to the electric car that we are used to seeing on the roads. The only difference is that the electric car is charged from the network or from a terminal at a gas station. Hydrogen transport itself generates electricity for itself.
As for the cost of such cars, they are more expensive. For example, Tesla models in the basic configuration will cost from 45 thousand dollars. Hydrogen analogues from Japan can be purchased for 57 thousand units. Bavarians, on the other hand, sell their cars on "green" fuel at a price of $ 50.
Considering practicality, it is easier to fill the car with gas (it will take about five minutes) than to wait half an hour (with fast charging, which is not permissible for all types of batteries) in the parking lot. This is the plus of hydrogen plants.
Another plus - fuel cells do not particularly need maintenance, and their working life is quite large. As for electric vehicles, their huge battery will require replacement in about five years due to the fact that it has many charge-discharge cycles. In freezing temperatures, the battery in electric vehicles is discharged much faster than in summer. But the element on the reaction of hydrogen oxidation does not suffer from this and stably produces electricity.
What are the prospects for hydrogen cars and when will they be seen on the road?
In Europe and the United States, the hydrogen car can already be found. However, they are still in the curiosity category. And today there are few prospects.
The main reason that this type of transport will not soon fill the roads of all countries is the lack of production capacities. First, it is necessary to establish hydrogen production. Moreover, it is necessary to reach such a level that, in addition to environmental friendliness, it is also fuel available to most motorists. In addition to the production of this gas, it is necessary to organize its transportation (although for this you can safely use the highways along which methane is transported), as well as equip many filling stations with appropriate terminals.
Secondly, each automaker will have to seriously modernize production lines, which requires considerable investment. In an unstable economy due to the outbreak of a global epidemic, few will take such risks.
If you look at the pace of development of electric transport, the process of popularization took place very quickly. However, the reason for the popularity of electric cars is the ability to save on fuel. And this is often the first reason why they are bought, and not for the sake of preserving the environment. In the case of hydrogen, it will not be possible to save money (at least now), because much more energy is spent on its production.
Pros and main disadvantages of hydrogen engines
So, let's summarize. The advantages of hydrogen fuel engines include the following factors:
- Environmentally friendly emission;
- Silent operation of the power unit (electric traction);
- In the case of using a fuel cell, frequent maintenance is not required;
- Fast refueling;
- Compared to electric vehicles, the propulsion system and energy source operate more stably even in freezing temperatures.
Although the development cannot be called a novelty, nevertheless, it still has a number of shortcomings that induce the average motorist to look at it with caution. Here are some of them:
- For hydrogen to ignite, it must be in a gaseous state. This creates certain difficulties. For example, special expensive compressors are required to compress light gases. There is also a problem with proper storage and transportation of fuel, as it is highly flammable;
- The cylinder, which will be installed on the car, will need to be periodically checked. To do this, the motorist will need to visit a specialized center, and this is an additional cost;
- In a hydrogen car, a huge battery is not used, however, the installation still weighs decently, which significantly affects the dynamic characteristics of the vehicle;
- Hydrogen - ignites at the slightest spark, so an accident involving such a car will be accompanied by a serious explosion. Given the irresponsible attitude of some drivers to their own safety and the lives of other road users, such vehicles cannot yet be released onto the roads.
Taking into account the interest of mankind in a clean environment, we can expect that a breakthrough will be made in the issue of finalizing the "green" transport. But when this happens, only time will tell.
In the meantime, watch the video review on the Toyota Mirai: