“The efficiency will be very high”: what are the prospects for the development of Russian and world hydrogen aviation

This year, Russia plans to complete research work on an aircraft hybrid power plant (HPU) using hydrogen as a fuel cell.

This was reported by the press service of the Central Institute of Aviation Motors named after P.I.

Baranova (CIAM).

“The plans for 2022 include testing the electrical part on the Sigma-4E, and at the next stage, the aircraft’s power plant will become hybrid due to the installation of a hydrogen fuel cell.

Its mass will be comparable to the mass of the battery," the Institute's website says.

• Electric aircraft "Sigma-4E"

• © CIAM

“Its (GSU. -

) will feature not only the use of a more powerful drive based on the VK-2500 engine, but also the use of liquid hydrogen as fuel and refrigerant.

With a decrease in temperature, the power of electrical machines on HTSC (high-temperature superconductivity. -

) almost triples while maintaining the weight and size characteristics, ”the CIAM specified.

In a RT commentary, Deputy Editor-in-Chief of the Aviapanorama magazine, Honored Military Pilot of Russia Vladimir Popov, stated that CIAM projects meet the current needs of modern aviation.

According to him, the institute

Baranova has the necessary base for the implementation of the plans.

“Hydrogen fuel cell can significantly improve the performance of hybrid power plants, especially promising is its use in conjunction with an electric motor.

The efficiency of using hydrogen as a fuel will be very high.

Profitability, the flight range of such aircraft should increase significantly, ”Popov explained.

"Perspective Direction"

Earlier, the United Engine Corporation JSC (UEC, part of Rostec) announced the start of work on the creation of hydrogen-fueled aircraft-type power plants.

Speaking on the sidelines of the International Aviation and Space Salon 2021, UEC General Designer Yuri Shmotin called the use of hydrogen fuel in aviation one of the most promising areas.

“We are considering two main technologies (obtaining H₂. -

): direct combustion of hydrogen fuel in modified gas turbines and electrochemical conversion of fuel into electrical energy using fuel cells,” Shmotin said.

The development of hydrogen as a fuel for aircraft began several decades ago.

The pioneer in this field was the Soviet Union.

The efforts of Soviet science and industry resulted in the creation of the Tu-155 flying laboratory based on the Tu-154 passenger aircraft.

The experimental machine received the NK-88 engine, which is also capable of operating on cryogenic fuel - hydrogen, which turned into a liquid state under the influence of extremely low temperatures.

At that time, the development of Soviet engineers had no analogues in the world.

Experts interviewed by RT noted that at that time the engineers tried to create a power plant that would make extensive use of the colossal energy potential inherent in N₂.

As you know, hydrogen is three times superior to traditional aviation kerosene in terms of thermal conductivity and is the leader in this indicator among all gaseous substances.

At the same time, H₂ is recognized as an environmentally friendly fuel, since during combustion it releases water and a small amount of nitrogen oxides.

However, hydrogen is explosive - detonation can occur at concentrations of H₂ in the environment at levels from 4 to 75%.

Storage and transportation of this gas can only be carried out in a liquid state, which requires maintaining extremely low temperatures.

Soviet engineers took these circumstances into account and therefore significantly redesigned the layout of the base liner so that the Tu-155 could use cryogenic fuel.

“In the tail section of the fuselage, where the passenger compartment was located, a sealed compartment was equipped, and a cryogenic tank for 20 cubic meters of liquid hydrogen was installed in it with screen-vacuum thermal insulation, which keeps the temperature in the tank below -253 ° C for a long time,” are given on on the Rostec website, the words of Valery Solozobov, Deputy General Director of Tupolev PJSC for design, who took part in the creation of the Tu-155.

Liquid hydrogen in the experimental aircraft was supplied using a high-pressure turbopump unit, and to ensure safety, almost all electrical wiring was removed from the cryogenic tank compartment, which eliminated the possibility of a spark.

• Experimental aircraft Tu-155

• RIA News

• © Vladimir Rodionov

In addition, engineers designed and installed a drainage system that removed hydrogen vapor from the tank to a safe distance from engines and sources of electricity.

In total, the use of liquid hydrogen required the creation of more than 30 additional onboard systems.

However, the Tu-155 never turned into a fully hydrogen aircraft.

Of the three engines of the flying laboratory, one worked on H₂.

The car made its first flight on April 15, 1988.

In 1989, the liner took off on another type of alternative fuel - liquefied natural gas.

The further fate of the Tu-155 is not reported in open sources, but the innovative aircraft did not go into operation.

Currently, in the world, in addition to CIAM and UEC, the Franco-German concern Airbus, one of the world's leading manufacturers of passenger and transport aircraft, is implementing hydrogen technologies in aircraft technology.

The company is confident that in the future the liners will certainly be refueled with the so-called green hydrogen, on which humanity has high hopes to achieve carbon neutrality.

However, to date, no optimal method has been developed for extracting “green hydrogen”, which is formed during electrolysis, an energy-intensive and costly process from a financial point of view.

In Russia, Rosnano is working to reduce costs, and in Germany, Siemens.

Both companies see a way out primarily in the improvement of wind generation technologies.

“The current agenda suggests that humanity is striving to switch to green hydrogen, but so far increasing its production is not too economically feasible.

For hydrogen to become “green”, electricity must come from renewable sources - these are windmills or solar panels, which for obvious reasons do not make sense to install everywhere, ”explained Alexander Frolov, deputy director general of the National Energy Institute, in an interview with RT.

Hydrogen infrastructure

Nevertheless, Airbus is optimistic about the development of green hydrogen extraction technologies.

The concern expects that its share in the total H₂ production will increase, while the cost of electrolysis will decrease.

As a result, by 2050, green hydrogen is expected to become one of the most common energy carriers on the planet.

The concern expects to bring aircraft powered by this type of fuel to the market by 2035.

In October 2020, Airbus published concept images of three promising passenger cars of various dimensions.

To create hydrogen aircraft, the concern plans to adapt technologies from the automotive and space industries, where H₂ is already used.

Also, engineers must solve problems with hydrogen storage, reduce the mass of equipment for the operation of new fuel and reduce its cost.

Airbus believes that in the future, airports will receive hydrogen from their own electrolysis plants.

Once removed, the H₂ will cool to a safe liquid state.

• Conceptual images of three passenger cars from Airbus

• © AIRBUS

Ambitious plans for the development of hydrogen aviation are also hatched by the industry of the United Kingdom.

In December last year, the British Institute of Aerospace Technology presented the FlyZero project, which provides for the emergence of a hydrogen wide-body airliner for 279 passengers.

It is assumed that, like the Tu-155, the aircraft will use liquid hydrogen stored in fuel tanks at a temperature of approximately -250 ° C.

According to the forecast of British experts, from the mid-2030s, hydrogen-powered aircraft will have better performance than traditional air transport.

According to Vladimir Popov, further development of technologies for the use of hydrogen fuel can indeed lead to the fact that H₂-powered aircraft will surpass machines with gas turbine power plants in a number of parameters.

Nevertheless, the achievement of concrete practical results in the field of hydrogen aviation is a prospect, at best, for the next 15-20 years, the RT interlocutor believes.

“The prospects for the use of hydrogen fuel in combination with powerful high-performance batteries look promising.

But it should be understood that a lot of technical issues must be resolved.

And the main thing here is safety.

Engineers need to create such an aircraft in which all aspects of fire and explosion hazards would be thought out at the highest level, ”Popov emphasized.

Alexander Frolov also believes that a sufficient technical base has not yet been accumulated to create a competitive H₂-powered aircraft.

According to the expert, in addition to ensuring safety, the unresolved issues of transportation and storage of hydrogen are an obstacle to the development of hydrogen aviation.

“It is difficult for me to imagine how exactly the hydrogen infrastructure associated with air traffic will be organized.

But I can assume that a large number of technical (engineering) problems will go off the agenda as the hydrogen energy system itself develops.

And with this question, it seems to me, many in the world are in a hurry, ”concluded Frolov.