INSTALLATION AND START UP REPORT CERTIFYING THE CORRECT
FUNCTIONALITY OF THE “AD HOC” REFUELLING STATION
Ref. Number:
LIFE+ MHYBUS LIFE 07-ENV/IT/000434
Project Acronym:
MHYBUS
Project Title:
Methane and Hydrogen blend for public city transport bus: technical demonstrative application and strategic policy measuresDeliverable n.
2.d
Partner responsible:
SOL
Author:
R. Nava (SOL)
INDEX
1. Scope of Document
2. Description of the “ad hoc” H2-CNG fuel station 3. Implementation main steps
1. Scope of document
Scope of this document is to describe the main steps carried out by SOL to design implement and test ad hoc fuel station for CNG blend supply in order to allow the bus to be refuelled with H2-CNG mixture in the necessary quantity to cover the well-defined road test.
The H2-CNG fuel station is realized inside an existing industrial hydrogen production facility based in Ravenna, Italy, nearby the ATM bus depot.
The main purpose of functional test is to grant the proper start-up of the fuel station in conjunction with the bus road test.
2.
Description of the “ad-hoc” H2-CNG fuel station
The design and implementation of the “ad-hoc” fuel station for H2-CNG blend supply for road test has been carried out within SubAction 2.4 of the project .
A dedicated area have been selected and set up inside the SOL facility area placed in Ravenna, (address Via Baiona 154) for implementation of the ad-hoc fuel station.
Main data of the ad-hoc fuel station are:
CH4/ H2 inlet feed pressure: 12 barg
H2-CNG (Hydromethane) blend outlet filling Pressure: 200 barg
Filling connector type. NGV-1 standard
H2-CNG blend composition: 15% vol. H2- 85% vol CH4
The ad-hoc fuel stations consists of the following main units:
1) CNG distribution line
Natural gas (CNG) used for production of Hydrometane blend of project MHYBUS is delivered to the fuel station area through a dedicated carbon steel pipeline (DN20 size) starting form the existing Sol facility CNG metering cabin.
The pipeline route is realized partially underground and partially aboveground and is equipeed with safety root valves and CNG flow totalizer (to measure and totalize the flow of CNG consumed into the ad hoc fuel station during the project).
Figure 1 shows a detail of the CNG pipeline with the CNG flow totalizer.
2) H2 distribution line
Hydrogen (H2) used for production of Hydrometane blend of project MHYBUS is delivered to the fuel station area in compressed form into n. 1 200 bar vertical type 16- cylinder bundle (total volume 800 liters WC) connected to the rest of plant through a flexible stainless steel pipe; line is also equipped with a safety root valve.
Figure 2 shows a detail of the H2 bundle.
3) H2-CNG mixing skid unit
H2 and CNG gases are blended at the defined % ratio of Hydrogen (15% vol. ± 2% tolerance) into a mixing skid unit that has been fully designed and realized by SOL as a dedicated parallel activity (out of the scope of the project).
The mixing unit consists of a skid including all the necessary components and devices for H2 and CNG gases safety handling and mixing.
The blending is realized at an intermediate pressure stage (12 bars).
An analysis instrumentation equipment is also part of the mixing unit to guarantee the correct % ratio of Hydrogen into the blend.
Figure 3 shows a detail of the H2-CNG skid.
Figure 4 shows a detail of the analysis panel with the % ratio of Hydrogen blend.
Figure 3: H2-CNG skid
4) H2-CNG compressor cabinet
The H2-CNG blend is compressed from an intermediate pressure stage to a final delivery high refilling pressure stage by means of a compressor cabinet.
The compressor cabinet is property of ENEA,and is part of a previous regional H2 project.
It has been transported to Ravenna and revamped in a fully customised by manufacturer in order to fulfil the project requirements of filling pressure, end filling connector, filling time. The compressor is open from one side and realized inside a 15 cm thickiness reinforced concrete cabinet as requested by Italian Regulations (dimensions 5 x 2,5 x 2,5 mts); the open front is anyway protected by one of the walls of the box protecting the ad hoc fuel station area.
The compressor is a 3-stage hydraulic piston suitable to deliver a maximum outlet pressure of 350 bars. Due to the limitation of the maximum filling pressure admitted into the bus storage system, the system is equipped with active safety devices to limit the filling pressure to 200 bar and with passive mechanical safety valves discharging to atmosphere in case of 110% overpressure reaching (220 bars).
Figure 5 shows a detail of the H2-CNG blend compressor cabinet.
Figure 5: H2-CNG compressor skid
5) HP storage Buffer
H2-CNG blend is stored inside n.3 bundles each of 200 bar, vertical type, 16-cylinder composition (800 liter WC each).
The total WC of 2.400 l guarantees a proper “reservoir” of HP blend in order to perform a fast refuelling of the bus.
In this configuration the main part of the bus refuelling is accomplished by pressure transfer of H2-CNG blend from the intermediate HP bundles to the bus storage system.
The compressor is used to complete the final “top-up” of the bus storage tank up to 200 barg. The connections between the HP bundles and the compressor cabinet are made with HP stainless steel flexible pipe and are protected from overpressure by means of safety valves.
Figure 6 shows a detail of the H2-CNG storage buffer.
6) Refuelling system connector
Bus Refuelling at 200 bars of the H2-CNG blend is realized by means of a special refuelling connector.
The system includes:
P/T control transmitter devices;
“Fail-safe” automatic shut-off valve with automatic opening/closure controller via PLC system by the control cabinet (see ch. 7);
Safety valve set at 110% of the refuelling pressure; Excess flow valve;
Pressure gauge for operator; Breakaway system;
Flexible refuelling hose;
End refuelling connector NGV-1 standard (NOT compatible with other connector for CH4 and H2 present inside the SOL facility for additional safety measure).
Figure 7 shows a detail of the refuelling system connector.
7) Electric feed and control board
The fuel station is designed to operate in automatic mode by means of a dedicated PLC system. The electrical feed and control of the ad-hoc fuel station is performed by means of n. 3 boards:
- N. 1 electrical feed distribution (Figure 8-A) - N. 1 control board of the mixing unit (Figure 8-B)
- N. 1 control board of the compressor cabinet (Figure 8-C)
Figure 8: fuel station electric feed and control boards
8-A 8-B
The ad hoc fuel station operates in two different modalities: MODALITA’ RIFORNIMENTO (”refuelling modality”):
in this modality the unit checks if all the safety signals are in proper status and in this case activates the refuelling of the vehicle.
Vehicle is refuelled in two steps; first step by means of gas transfer from the HP storage bundle into the vehicle tank, second step through also a compression ”top-up” stage.
Before activation of this modality SOL trained operator perform the connection between vehicle and the refuelling system of the ad hoc station.
Normal refuelling takes approximately 30 minutes.
After a refuelling the pressure inside the intermediate buffer bundles is lower and needs to be restored to initial 200 bars capacity.
MODALITA’ RIPRISTINO (”bundle restore modality”):
in this modality the unit checks if all the safety signals are in proper status and in this case activates the restoring of the initial 200 bars capacity of the intermediate bundles.
Bundles are restored by means of production of new H2-CNG blend inside the mixing unit, that is compressed and transferred into the bundles through the compression cabinet.
3 Implementation main steps
The mains steps of the design and implementation of the “ad-hoc” fuel station for H2-CNG blend supply for road test been carried out by SOL within SubAction 2.4 are below summarized.
1st quarter 2011: Project Definition
Step one: selection of dedicated area for project inside SOL Ravenna Plant facility
For the implementation of the ad-hoc fuel station inside SOL facility it has been selected an existing storage box for hydrogen trailers which is already equipped with proper fire protection systems.
Other issues considered in selection: bus access, separation of zones, safety distances, utilities availability.
Figure 9 shows the existing storage box before implementation of the fuel station.
Step two: assessment of project schemes and plot plan
The plot plan have been developed considering technical, operating and normative requirements and the following additional issues: bus access, separation of zones, safety distances, utilities availability.
Figure 10 shows the Plot Plan of the fuel station
Figure 11a/b shows the bus entry/exit route inside and outside of the SOL facility agreed with the bus operator.
Figure 11a: Bus entry route in SOL facility
Step three: preparation of new Hydromethane safety datasheet
A dedicated safety datasheet containing all the safety characteristics for the “new product” hydromethane blend has been developed by SOL safety department.
Figure 12 shows the cover of the safety datashhet for Hydromethane.
Figure 12: Hydromethane safety datasheet
2nd quarter 2011: Project Submission
Step four: Fire Department Approval for the refuelling station infrastructure
Preparation and issue of the whole set of documentation for Permit Procedure (“project” and “as-built” approvals) with reference to the applicable regulation for hydromethane and the direct involvement of Italian Fire Brigades.
Picture 13 shows the Fire Brigade Approval Release
P Figure 13: Fire Brigade approval
Step five: new equipment construction
The H2-CNG mixing unit is realized by SOL specifically for MHYBUS project with integrated analysis of H2 ratio for blend preparation at known and defined H2 ratio.
3rd quarter 2011: fuel station implementation Step six: construction
During the 3rd quarter of year 2011 the installation of the ad-hoc Hydromethane fuel station has been mechanically and electrically completed in SOL facility.
Figure 26: system blank start-up Figure 27: system pressure start-up
Beginning 2012: fuel station functionality testing Step seven: system check and system functionality test
During the beginning of 2012 SOL have performed the system check and the functionality start-up test in collaboration with authorized responsibles nominated for the ENEA minirete plant in order to check the main specifications of the plant.
4. Summary test report
The ad hoc hydromethane fuel station has been mechanically and electrically completed in December 2011.
The check of the system and the functionality test of the system have been performed beginning of 2012.
The fuel station will be in operation until completion of the scheduled road test phase of the bus. During this period SOL will provide the fuels (hydrogen in compressed form locally produced and natural gas taken by the grid) for the desired H2-CNG blend preparation.
