Hydrogen Production

The QRA study was focused on the hydrogen storage as the largest hydrogen inventory in the plant. The hydrogen storage (compressed gaseous hydrogen, CGH2) has a total capacity of 5000 Nm3 (±420 kg of H2) at a pressure of 3 MPa and ambient temperature. It mainly consists of two large cylindrical CGH2 tank installed outdoors and its piping system. The piping systems used to connect the tank to other equipments such as electrolysers, pressure relief devices, instrumentations, end-use technologies, and other outlines. Each of them, of course, may break or rupture in an infinite number of ways. By considering the factors above (section 5.1), the following scenarios have been assessed: 0) Instantaneous release of the complete hydrogen inventory caused by tank rupture; (2) Continuous release of hydrogen in liquid or vapour phase through a hole in the tank; (3) Continuous release of hydrogen in vapour phase due to relief valves fail open; (4) Continuous release of hydrogen in vapour phase due to rupture discs ruptures prematurely; ( ) Continuous release of hydrogen due to a full-bore rupture of the vapour lines.

The summary of the scenarios considered for the hydrogen plant is given in Table 5-1. The table shows the five accident scenarios A-E, including with following information: undesired events, inner diameter (tank, pipe, and hole), release direction, and discharge data (i.e. flow rate or mass, and release duration. Due to inadequate information the diameter of pipes and holes were estimated from a similar study (e.g. LPG).

Table 5-1 List of accident scenarios for the GH2 storage at production plant

Scena rios

Undesired events

Inner diameter (mm)

Release Direction

Type of

Bund Surface

Discharge Data

Type

Phase

Tank

Pipe

Hole

Flowrate (kg/s) or mass (kg)

Duration (s, or inst)

A

Tank rupture

Vapor

N/A

-

-

-

N/A

445

inst.

B

Tank leak

Vapor

N/A

-

50.8

Down

N/A

3.3

135.9

C

Relief valve

Vapor

N/A

50.8

12.7

Vertical

N/A

0.3

17550.3

D

Rupture disc

vapor

N/A

50.8

50.8

Vertical

N/A

2.3

194.9

E

Line rupture

Vapor

N/A

50.8

50.8

Vertical

N/A

2.3

194.9

Getting Started With Dumbbells

Getting Started With Dumbbells

The use of dumbbells gives you a much more comprehensive strengthening effect because the workout engages your stabilizer muscles, in addition to the muscle you may be pin-pointing. Without all of the belts and artificial stabilizers of a machine, you also engage your core muscles, which are your body's natural stabilizers.

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