Industry Trends & Engineered Solutions Library

New Technology Increases Safety of Hydrogen Filling Stations in Warehouse Operations

Thursday, August 13, 2015

Hydrogen-fuel-cell-powered material handling equipment is becoming increasingly popular in warehouse operations.  Warehouse managers are benefiting from increased productivity when their fleets make the switch from battery-powered to fuel-cell-powered material handling equipment. Air_Liquide_hydrogen_fork_truck-1

Unlike batteries, fuel cells can run uninterrupted for the duration of an eight-hour shift.  Batteries have been known to die at least once per shift and can take up to thirty minutes to changeover.  The fuel-cell-powered equipment only needs to be refueled once at the end of each eight-hour shift and the process takes three minutes or less. 

Another added benefit – fuel cells maintain constant power while in use.  Batteries on the other hand, show reduced voltage toward the end of their charge.

Construction of a Hydrogen Filling Station

Hydrogen filling stations are typically placed in convenient locations within the warehouse to minimize travel time for material handling equipment.  The equipment used to produce or store the hydrogen in most warehouses is located outside, hundreds and possibly even thousands of feet from the dispenser.  Connecting the two, in order to transport the hydrogen, can present a challenge.

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Conventional methods use short lengths of straight seamless tubing joined with fittings to connect the storage tanks to the dispenser.  With this process, installing the tubes on the vertical portion of the building can be especially difficult. 

Another major drawback to connecting equipment inside of the 15-foot radius.  shorter lengths with fittings is that NFPA 2, Hydrogen Technologies Code, suggests that a 15-foot, Class I, Division 2, Group B hazardous area surrounds each connection.  As a result, engineers may be forced to re-route the tubing to avoid this area.  If re-routing is not an option, engineers may have to use explosion-proof

 

The number of connections has a direct impact on the overall cost of the station, so most engineers try to minimize them.  Minimizing the connections not only reduces the cost of the station, but it also makes the warehouse safer by minimizing leak points. 

Air_Liquide_hydrogen_fork_truck-HydrogenOne solution that is becoming increasingly popular is the use of stainless steel coil tubing to connect the hydrogen storage tanks to the dispenser.  Depending on the size of tubing used, the coils can sometimes be eighty times longer than a single stick of tube.  In this case, over a 1600-foot run, straight seamless tubing at standard length of 20 feet would need 79 intermediate connections, while stainless coil tubing requires zero.

Stainless steel coil tubing can easily be uncoiled in the field using a straightener and pay-off system.  Stainless coil tubing has the added benefit of easier storage, and shipping and handling in the field compared to traditional straight seamless tubing.

Find the Tubing That Fits Your Operation

Very few companies produce uniquely designed stainless steel coil tubing capable of transporting hydrogen over long distances.  This is not the standard seamless tubing shown in many catalogs.  Compared to the standard offerings, uniquely designed stainless coil tubing has many benefits:

• Increased Safety – Fewer connections means fewer leak points, decreasing the potential of hydrogen

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• Improved Reliability – Using fewer fittings increases overall system integrity and minimizes maintenance. escaping from the system.

• Reduced Scrap – Stainless coil tubing can be cut to exact lengths in the field, minimizing waste.

• Reduced Installation Costs – Installing stainless steel coil tubing saves time and money by reducing the labor and material costs associated with joining shorter lengths.

• Improved Flow – Each fitting adds friction to a system, interrupting flow and reducing overall efficiency.

Conclusion

The same factors that increase safety and control hazards also reduce installation costs.  The equation is a simple one. Installing seamless stainless steel coil tubing to transport hydrogen over long distances saves time and money by reducing the labor and minimizing fitting costs. 

Download our white paper for more information:

Advantages of Hydrogen Fuel Cell-Powered Forklifts

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