APT, Czech republic

05/03/2021

Question 9: „Hazardous areas“ are designated for hydrogen filling stations. What does this mean for operators and customers of the gas station?

Answer: A hazardous area is defined as an area in which there is or may develop an explosive atmosphere at concentrations requiring special precautions during the construction, installation and use of a compressed hydrogen filling station.

To hazardous areas can refer an area, classified as Zone 0, in which an explosive gas atmosphere exists continuously, for a long period of time or very often. Such zones cannot be located at hydrogen filling stations where customers and their vehicles are located.

Zone 1 is a space in which it is necessary to consider the periodic possibility of an explosive atmosphere. Such a zone is present at the vacinity of a filling station near the quick-disconnect filling connection at the moment of connecting the filling connection, during the filling process and disconnecting the filling connection. Zone 1 represents a ball with a radius of 25 centimeters.

Zone 2 is an area where there is no need to expect an explosive atmosphere to develop. But if this happens, then, most likely, it happens extremely rarely and in an extremely short time. Zone 2 extends around the dispensing device at a distance of 20 centimeters from its surface in all directions.

A non-explosive area is an area where an explosive atmosphere is not expected and therefore no special precautions need be taken during construction, installation and exploatation of a hydrogen filling station. This zone includes all other spaces available to the customer at the gas station, with the exception of the restricted areas mentioned above. However, in order to prevent dangerous situations at gas stations, there is a ban on smoking, a ban on the use of open flames and a ban on actions that can cause a fire in the area of the gas station. Prevention also includes sophisticated design principles, the use of quality materials, and rigorous functional testing in the design and construction of APT hydrogen filling stations. All of the above guarantees the safety of the station operation. Instructions for the correct operation of a hydrogen filling station should be posted in different places, and duplicated in several languages.

Question 9: „Hazardous areas“ are designated for hydrogen filling stations. What does this mean for operators and customers of the gas station?Answer: A hazardous area is defined as an area in which there is or may develop an explosive atmosphere at concentrations requiring special precautions d...

26/02/2021

Question 8: What is the difference between a public hydrogen filling station and a private hydrogen filling station?
Answer: The main difference is that private hydrogen filling stations serve a closed group of customers, that is, a closed company, or even a private group of individuals. At such stations, as a rule, only the hydrogen consumption by mobile devices is recorded. Therefore, there is no need for a commercial measurement of the amount of hydrogen consumed in order to accurately calculate the price. In this case, the purchase price of a private filling station will be significantly lower. The high pressure compressed hydrogen reservoir can be optimized according to the station’s operating mode, which can also be done with low filling rates.

A public hydrogen filling station serves the public and must be equipped with commercial instruments for measuring the amount of hydrogen consumed and must have a valid metrological certification (see Act No. 505/1990 Coll.). A public hydrogen filling station must also be equipped with a large supply of compressed hydrogen to meet the population’s irregular needs of fuel. These are usually high-speed filling stations. For public hydrogen filling stations, Act No. 311/2006 Coll. Is applicable.

From the point of view of operational safety, both variants of gas stations are equivalent. When designing and manufacturing devices of this class, the principles of maximum safety and operational reliability are always observed.

Question 8: What is the difference between a public hydrogen filling station and a private hydrogen filling station? Answer: The main difference is that private hydrogen filling stations serve a closed group of customers, that is, a closed company, or even a private group of individuals. At such sta...

19/02/2021

Question 7: What are the requirements for quick-release connection and refueling hoses at hydrogen filling stations?
Answer: The quick-release filling connection must comply with the requirements of the ČSN EN ISO 17268 standard “Hydrogen gas – interface filling stations for land vehicles”. It must be able to detect overpressure. Hoses, that provide a conductive connection to the mobile device can be used for filling only. These hoses must withstand the flow of hydrogen at its operating pressure. The filling hose should not be shorter than 3 m and longer than 5 m. The design of the filling quick-release connection excludes its use for other purposes, except for filling the tanks of hydrogen mobile devices. The quick-release coupling allows filling only if it is tightly and correctly connected to the counterpart of the filled vehicle gas tank, preventing its unintentional disconnection. The quick-release coupling can only be disconnected after the pressure has been released. If the mechanical stress, applied to the filling hose, exceeds a certain limit, the quick-release coupling mechanism will mechanically disconnect itself from the counterpart of the filled tank, the hydrogen supply will be shut off, and the filler neck of the vehicle will also be automatically closed. The force required to automatically disconnect the filling device is significantly lower than the breaking strength of the filling hose itself or the force required to damage a quick-release coupling or the filling device. The filling hose has a certain electrical conductivity. This circumstance is necessary to bring the filling station and the vehicle to the same potential, thereby preventing the possibility of ignition due to a voltage jump.

Question 7: What are the requirements for quick-release connection and refueling hoses at hydrogen filling stations? Answer: The quick-release filling connection must comply with the requirements of the ČSN EN ISO 17268 standard “Hydrogen gas – interface filling stations for land vehicles”. I...

19/02/2021

Question 6: Where can the hydrogen refueling be placed?
Answer: The equipment of a hydrogen filling station is located outdoors so that leaked hydrogen cannot accumulate in closed building structures. Some parts of the filling station can be installed in closed spaces, which must be ventilated in accordance with the rules and conditions specified in the Certified Methodology for the Construction and Operation of Compressed Hydrogen Refueling Stations for Mobile Equipment in the technical regulations issued by the Czech Gas Association TPG 304 03. Gas stations must be equipped with automatic valves providing automatic shutdown of hydrogen sources in the event of a hazardous situation. Technological parts of the station must be protected from access by unauthorized persons.

APT, spol. s r. o. developed complexes of hydrogen filling stations, the main components of which are placed in compact, convenient containers. This provides good weather protection for the plant and also simplifies on-site installation and project preparation. An example of such a station, located on the premises of the Institute for Nuclear Research ÚJV Řež, is shown in the photo below. Each container is designed by APT, spol. s r. o. individually, according to the investor’s requirements.

A small hydrogen filling station from APT located in the ÚJV Řež complex. On the front side of the container there is a filling device for vehicles mounted on a conductive surface (two gray metal strips in the lower left part, connected to the station grounding system).
https://www.apt.cz/en/newspaper/q6en

19/02/2021

Question 5: You are claiming that a hydrogen refueling station fills vehicles or other mobile devices at a pressure, usually 350 or 700 bar. What conditions are associated with this pressure? What other variables could arise around hydrogen refueling?

Answer: The pressure levels quoted are based on standard gas conditions, i.e. 15 ° C. We are also faced with the volume of hydrogen in Nm3, which is determined at a temperature of 15 ° C and a pressure of 101.325 kPa. From the user’s point of view, most often they talk about the injected kilograms of hydrogen. To convert Nm3 to kg of hydrogen, the formula 11.2 Nm3 = 1 kg is applied. The current market price for hydrogen at public hydrogen filling stations in Western Europe ranges from € 10 to € 15 per kg of hydrogen filled into a vehicle. Hydrogen prices are expected to fall in the future.

Question 5: You are claiming that a hydrogen refueling station fills vehicles or other mobile devices at a pressure, usually 350 or 700 bar. What conditions are associated with this pressure? What other variables could arise around hydrogen refueling? Answer: The pressure levels quoted are based on....

29/01/2021

Question 4: You state that a hydrogen refueling station is used to fuel vehicles. Can a hydrogen refueling station also refuel special hydrogen fuel cell machinery such as loaders, work equipment, and handling equipment in general?

Answer: Yes, it is possible. A prerequisite is a compatible connection according to the international standard and the corresponding technical parameters of the fuel tank in the mobile device. According to information from other countries, such “special” devices are usually charged up to 350 bar. For these purposes, APT, spol. s r. o. developed hydrogen filling stations of small design with the required capacity for refueling forklift trucks with emission-free operation. These stations are compact, easy to move, and thus can quickly meet the needs of different users. Small filling stations are designed for filling with hydrogen at a pressure of 250, 350 or 700 bar. The user specifies an individual specification when placing an order.

Question 4: You state that a hydrogen refueling station is used to fuel vehicles. Can a hydrogen refueling station also refuel special hydrogen fuel cell machinery such as loaders, work equipment, and handling equipment in general? Answer: Yes, it is possible. A prerequisite is a compatible connecti...

15/01/2021

Question 3: How can an ordinary user at a hydrogen filling station ensure that the filling hose is connected correctly to avoid the hazards associated with both the high pressure and the hydrogen itself?

Answer: The filling nozzle is a complex device whose function is defined by international technical standards. Compliance with these standards must be confirmed by quality certificates. The design of this component was focused on user comfort and protection.

The filling hose nozzle is inserted into the filler neck on the vehicle and is fixed in this position by turning the lever on the injector handle. In this case, there is an analogy with the systems for refueling vehicles with LNG, which have been used throughout the planet for many years.

In addition, the automatic sequence of the refueling process – first of all, includes checking the tightness of the connection of the refueling hose to the vehicle tank. For this purpose, the residual hydrogen pressure in the vehicle tank and in the refueling hose is used. When the hose is connected to the vehicle tank, the pressure is measured over a period of time. The next filling phase can only begin after confirming that there is no pressure drop in the system. If a pressure drop is detected, the control system stops the process and reports an error: leaking hose connection. A similar error can also occur if the O-rings on the filling nozzle have been damaged or dirt has got into the joint. The connection will also be leaky if the filling nozzle is connected to the wrong counterpart. This malfunction can be easily eliminated by the station technician.

13/01/2021

Question 2: How is the separation of systems with different hydrogen pressures ensured, so that a vehicle with a maximum filling pressure of 350 bar cannot be connected to a filling system with a filling pressure of 700 bar?

Answer: Hydrogen filling stations and the vehicles themselves on hydrogen fuel cells are equipped with standardized filling connections that meet international technical standards. These standards, among other things, ensure the required level of compatibility between filling stations and vehicles from different manufacturers.

The correct operation and safety of the system is ensured by a system of mechanical locks, which allows the connection of a filling end with a pressure of 700, 350 and 250 bar to the tank of the vehicle, designed for a pressure of 700 bar. On the other hand, the mechanical locking system will prevent the connection of a 700 bar filling end to a 350 bar vehicle tank.

13/01/2021

Question 1: What are the main functional parts of a hydrogen filling station for road transport?
Answer: A hydrogen filling station (hereinafter referred to as HFS) is a complex, specialized technical device operating with hydrogen at high pressures, up to 900 bar. HFS ensures compliance with technological processes, taking into account all the chemical and physical properties of hydrogen and operational safety when fuel is supplied to a vehicle.

The main functional components of the HFS:

1. The basic part of the HFS is the hydrogen supply system to the HFS itself. Typically, the working stock pressure is about 25 bar.

2. Compressor unit designed to increase the hydrogen pressure. From the working stock, with a pressure of about 25 bar, hydrogen is pumped (using a compressor unit) into high-pressure buffers (hereinafter referred to as HPB), which are designed to provide the pressure required for fuelling the vehicle. However, if necessary, the input of the compressor unit can be re-connected to the output of the buffer of the first stage of the cascade. In this case, the compressor will compress the hydrogen to higher values (for example, from 300 bar to 500 and even 900 bar). The meaning of the concept of cascade pressure increase is to reduce the energy consumption of the process and limit the unwanted heating of the medium during the compression process (the equation of state with an initial temperature of 15 ° C is applicable to the filling of the buffer tanks).

3. HPB included in a multistage cascade. Each stage of the cascade consists of high-pressure cylinders connected in such a way that they form the required volume.

The hydrogen in the BVD under operating pressure represents the operational fuel reserve at the filling station, which serves to accelerate the process of filling of the connected vehicle.

Customer requirements for a gas station include, among other things, a description of the types of vehicles to be refuelled at a given station (for example, buses with a filling pressure of 350 bar and a tank capacity of about 30 kg of hydrogen or cars with a refuelling filling of 700 bar and a capacity tank about 6 kg), as well as the frequency and requirements for the filling rate (for example, the transport company owns 15 buses that must be filled within 3 hours, and also, in the future, expects to fill 5 more cars per day). Based on these data, the required operating pressure of hydrogen in the HPB is calculated, as the division into pressure levels of the cascades (for example, levels of 300, 500 and 900 bar).

4. Valve block with the control system, which controls the outlet of the compressor unit and thus allows the individual stages of the high-pressure buffer cascade to be gradually filled. The main variables influencing the operation of the valve block are the pressure in the cascade section and the temperature of the cylinders. Also, the control system controls the hydrogen by-pass through automatic valves between the individual pressure sections. The control variable in this case is the pressure in the vehicle tank and the hydrogen flow rate through the mass flow meter (an integral part of the dispenser stand. When the pressure in the buffer falls below the set minimum, and as a result, the flow of the medium decreases, the system will switch to another section of the buffer with a higher working pressure). In the case of filling at a pressure of 700 bar, the temperature of the filled tank is also taken into account.

5. Dispenser – a device for the controlled supply of hydrogen to the vehicle tank. The dispenser performs several functions at once, in particular – ensuring the safety of the filling process (tight connection with the intake neck of the vehicle tank, tightness of the system itself, preventing damage to the hose, limiting the hydrogen consumption rate to 60 g / s, monitoring the pressure and temperature of the vehicle tank). In addition, the dispenser functions as a control system sensor for switching sections of the buffer cascade, as a commercial measurement for determining the fuel price, and also provides hydrogen cooling during filling at 700 bar. In this case, the dispenser unit is able to lower the temperature of the pumped fuel down to -40 ° C. The device is equipped with a banking terminal for payment and a registration system for drivers and filled vehicles.

6. The control system controls all processes taking place at the filling station. The system evaluates the information received from the sensors and maintains the technological process within the established operating limits. If any of the parameters is exceeded, the control system initiates an automatic sequence of actions aimed at bringing the station to a safe state. It communicates with the outside world, provides communication with higher-level control and monitoring systems, supports remote maintenance and self-diagnostics.

13/01/2021

In the automotive industry, the use of low-emission vehicles based on hydrogen fuel cells has come to the fore in recent years. Basic information on this topic is available in the press and other media. However, what is missing is the answers to simple questions that are often asked by ordinary users. The concept of using hydrogen fuel cell vehicles implies significant changes in both technological equipment and the transport infrastructure itself.

In the course of our work we have selected a number of interesting questions from those received by APT, spol. s r.о., which is one of the leaders in this topic. As evidence, we can cite the fact that the company APT, spol. s r.o. developed a certified methodology for the construction and operation of hydrogen filling stations, which later became the basis for the state technical standard TPG 304 03, and also completed the construction of the first two hydrogen filling stations in cooperation with the Institute for Nuclear Research ÚJV – Řež.

We decided to supplement the information on this topic, available in open sources, and share our experience in the field of practical aspects of infrastructure, everyday use, as well as data on the possibilities of potential investors in the field of hydrogen transport.

In the Newspaper section, we will regularly publish articles dealing with certain aspects of this topic. Also, we will be glad to any of your additional questions sent to [email protected].