Objectives for the development of advanced automotive CNG storage system and vehicle concepts :

INGAS meeting, Berlin, 16 March 2010INGAS meeting, Berlin, 16 March 2010

INGAS INtegrated GAS PowertrainINGAS INtegrated GAS Powertrain

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Objectives for the development of advanced automotive CNG storage system and vehicle concepts :

• Extended driving range (in the order of 500km) at acceptable weight, volume, costs;

• Compatibility of storage components with different gas qualities (oil/sulphur content, methane/hydrogen blends);

• Advanced CNG storage components, such as shut off-valves, electronic pressure regulator to ensure a safe and accurately controlled CNG supply at the rail;

• Development of a highly integrated storage module which is intrinsically safer that conventional solutions currently adopted that allows an optimized packaging as well for automotive assembly processes;

• New modular design and construction concepts for advanced CNG vehicles including higher storage capacities, and advanced safety concepts.

• The project has to deliver recommendations for further modifications of EC regulation ECE R110 based on scientific validation of burst factors and on cylinder validation with long term pressure tests.

SP-B1 “Gas storage for CNG engines”SP-B1 “Gas storage for CNG engines”



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SP-B1: Reviewers’ Comments n.1 & 2 and ResponsesSP-B1: Reviewers’ Comments n.1 & 2 and Responses

• According to the DoW a class C prototype demonstrator shall have integrated the InGAS tank system with a driving range larger than 500 km. From Deliverable DB1.01 it can be inferred that this is not anymore the case. Please comment on this.

• To be clarified is the aim to address recommendations for further modifications of ECE 110 regulation. While this in principle is absolutely legitimate, it would be misleading to assume that the requested modifications will be accepted. The project should be based only on the current rules on the matter.

As documented in the 12-month progress report, the possible solution for the C-segment demonstrator vehicle, which has been identified by CRF, would enable a vehicle driving range in the order of 500km at an operating pressure of 260 bar as per US standards by equipping the vehicle with a storage capacity of approx. 130 litres. Indeed, in CRF’s interpretation of the DoW, the option does seem to be open to consider higher operating pressures than currently specified in the ECE R110 regulations which are generally considered to be restrictive as regards achieving a vehicle driving range that exceeds 400km. In particular, one of the stated objectives of WP B1.2 is to address the “regulatory aspects for advanced lightweight pressure vessels with proposed improvement of the current ECE R110 regulations”.

Nevertheless the solution which has been proposed by CRF also reflects the past experience of Xperion regarding vessel diameters; specifically CRF and Xperion have attempted to utilise to the full current solutions and best practice in vessel design. The added benefit to the project from the perspective of innovation to increase the dimensions of the vessels to provide approx. 145 litres of gas storage capacity (to yield a driving range of approx. 500km at an operating pressure of 200 bar) is unclear, however, also bearing in mind that the objectives of the virtual design optimisation of WPB1.4 and WPB1.5, which focuses on a B-segment vehicle, remain that of a 500 km driving range.



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Physical demonstrator: Proposed SolutionPhysical demonstrator: Proposed Solution

Parameter

Cylinder

Diameter[mm]

Length[mm]

Capacity[l]

A 390 760 60

B 204 670 15,2

C 204 780 18,4

D 204 780 18,4

E 204 780 18,4

130,4

PROPOSED SOLUTION

TOTAL LITRES

Capacity 130Lit: Capacity 130Lit: ca.400km @ 200 bar (EU)ca.400km @ 200 bar (EU)ca.500km @ 260 bar (US)ca.500km @ 260 bar (US)

Capacity 145Lit: ca.500km @ 200 bar (EU)

For C-segment demonstrator:



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Virtual demonstrator: Proposed SolutionVirtual demonstrator: Proposed Solution

Capacity 115Lit: ca.450km @ 200 bar (EU)ca.500km @ 260 bar (US)

Capacity 130Lit: Capacity 130Lit: ca.500km @ 200 bar (EU)ca.500km @ 200 bar (EU)

For B-segment demonstrator:

ABBC

Parameter

Cylinder

Diameter[mm]

Capacity[l]

A 422 71

B 248 22,5

C 190 14,5

130,5

PROPOSED SOLUTION

TOTAL LITRES



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SP-B1: Reviewers’ Comment n.7SP-B1: Reviewers’ Comment n.7

• The preliminary design of the rear module shows a solution (pg. 154) for securing the vessels to the frame, which - although practical for assembling/disassembling the vessels - seems to be particularly critical when considering side impacts. Of course, the planned safety analysis will tell more about this issue. Please comment on the time/budget issues in case of re-design.

Fig. B1.32 Preliminary design of rear module incorporating a functionalized frame which has been developed with reference to potential installation on a B-segment car based on a twist-axle type rear suspension system and providing a nominal CNG storage capacity of 122.5 litres



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Top view

Deformable brackets (if necessary)

The solution for securing the vessels to the frame which has been proposed by CRF is indeed innovative, the intention being to improve the structural properties of the rear section of the vehicle by exploiting the stiffness of the vessels themselves. As indicated by the reviewer(s), this may indeed prove to be critical with respect to the crash analyses.

However it should be pointed out also that a relatively significant deformation space around the storage module sub-assembly does exist when mounted within the chassis of the vehicle.

SP-B1: Response to Reviewers’ Comment n.7SP-B1: Response to Reviewers’ Comment n.7



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SP-B1: Response to Reviewers’ Comment n.7 (cont’d)SP-B1: Response to Reviewers’ Comment n.7 (cont’d)

In any case such a re-design could be included as part of the ‘design optimisation and validation’ activities of Tasks B1.5.1 and B1.5.2; correspondingly, the implications on the overall timeplan are not foreseen to be particularly significant even if this proves to be necessary.

A ‘fall-back’ option (ie. in the case of inadequate crash behaviour during simulation) would be:

• to re-design the rear overhang of the vehicle in order to increase the deformation space further;

• to adopt deformable brackets, in longitudinal direction, under rear crash loads;

• to use a more conventional belt-type solution which will require a re-design of the frame and brackets.



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SP-B1: Reviewers’ Comments n.3 and ResponseSP-B1: Reviewers’ Comments n.3 and Response

• Indicated weight savings with 500 km range for composite cylinders instead of steel cylinders are not in line with kg/l details for three show alternatives addressed. Please comment on this

The total mass of the complete system is estimated about of 130kg including all components:

- vessels, - methane, - valves, - tubes, - pressure regulator, - control unit- fitting system, etc.).

Indeed 130kg can be considered to be an overestimate: According to detailed calculations, the true total weight of the entire system on the prototype vehicle will be approximately 120kg.

The weight of the vessels fall into the specified range required: Please see also Comment 6.



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SP-B1: Reviewers’ Comment n.6 and ResponseSP-B1: Reviewers’ Comment n.6 and Response

Type III vessels can achieve attractive weight performance, but have substantial disadvantages:

Costs

Xperion have assessed Type III cylinders as well, seeing that the cost target of <5€/l can not be achieved with this type of cylinders. The cost of Type III cylinders are significant higher compared to InGAS Type IV vessels and are in the range of 8-10€/l (=nearly double costs!) due to:

- costs of the metal liners compared to blow former plastic liners, - higher material costs resulting from “pure” CF-composite instead of the hybrid GF/CF-

composite INGAS design.

Reliability

The weak point of Type III is the fatigue behaviour of the liner (ref: EU-Project StorHy)

Permeation

The Xperion CNG type IV vessels were intensively tested and fulfil all permeation requirements of ECE R110. By new advanced plastic liner materials, also the permeation requirement of a pure H2 vessel can be fulfilled by type IV vessels.

• The InGAS development targets do not comply with the current state of the art. The gravimetric storage density of 0,45 kg/l for a pressure vessel type IV does not seem to be competitive with the current production of type III, like e.g. those produced by FABER with steel liner and carbon fibre winding, which exhibit a value of 0.41/0.42 kg/l and avoid all the problems related with the permeation of thermoplastic liners. Please comment on this.



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SP-B1: Reviewers’ Comment n.6 and Response (cont’d)SP-B1: Reviewers’ Comment n.6 and Response (cont’d)

Xperion aims to identify the best compromise regarding price and weight by exploiting a hybrid (GF + CF), the aim being to achieve weight performance of 0,45 kg/l at a price below 5 €/l. These are indeed highly ambitious targets when compared to the CNG Type III or IV vessel solutions currently on the market.

0%

50%

100%

150%

200%

250%

Type I: Steel Type III:L: Aluminium

C: CF

Type IV:L: Plastic

C: CF

Type IV:L: Plastic

C: GF

INGAS Gen1.1

Type IV:L: PlasticC: Hybrid

INGAS Gen1.2


INGAS Gen1.3


Relative Weight

Relative Volume

Relative Cost

Weight: 0,35 kg/l

rel. Vol: 0,94

Cost: 5 €/l

1 kg/l

1 rel. Vol

4 €/l

INGAS Development- More than 40 vessels designs- More then 250 vessel tests

Latest Generation



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SP-B1: Reviewers’ Comments n.4 and Response SP-B1: Reviewers’ Comments n.4 and Response

• The costs of an E200NGT vehicle today are already approximately € 3.500,00 higher (without mandatory automatic gear box for € 2.000,00) than that of an equivalent E200 compressor car. If the total costs of the new proposed InGAS vessel system are estimated to be 50% higher than today’s steel based solutions, will this be accepted by prospective customers? Please comment.

The example referred to regards the Mercedes E200 NGT Kompressor (Bi-fuel) which uses four Type I vessels:

The objective of the InGAS project is to develop solutions for economy class vehicles using Type IV vessels which remain highly competitive in this respect.



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InGAS solution Type IV has a storage volume of 130 lt whereas conventional Type I solutions are 85 lt.

Vehicle costs of current advanced CNG vehicles with a turbocharged ICE as the Passat ECO-Fuel are less than €3000 more compared to the gasoline version and “only” €1000 to the Diesel version.

The overall attractiveness to customers of the CNG versions of vehicles is thanks to lower taxes, public incentive programmes (eg. In Germany and Italy) in addition to the significantly lower fuel cost.

InGAS developments aim a significant weight reduction at an acceptable cost in the range €1.00-€1.50/l per compared to Type I, achieving a weight reduction of 60kg-70kg on system level.

The EU Project Super Light Car identified weight reduction potentials for solutions that 2€/kg.

The INGAS Hybrid vessel should enable approx. less than 2.50€/kg.

Hybrid vessel solution is particularly attractive when:• OEMs can avoid additional costs by adapting the rear axle, suspension etc. or • Cars can achieve the same pay load without modification.

KW CO2 g/km Additional Costs Fuel Costs

Passat 1,8 TSI DSG 118 kW 169 Reference Reference

Passat 2,0 ,TDI, DSG 125 kW 159 + 1.700 € 90%

CNG 1,4 TSI Eco Fuel, DSG

110 kW 119 + 2.830 € 60%



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• The use of methane and hydrogen blends as fuels shows drawbacks regarding operating range with full fuel tanks and also difficulties concerning the fuel use and distribution due to present restrictions (ECE R110) concerning hydrogen share in the methane gas. The definition of hydrogen content is somewhat vague. Embrittlement of CNG tanks via hydrogen is mentioned as a potential problem and should be addressed in more detail.

The issue of H2 embrittlement of CNG steel tanks is topic of a study within SPB0. The study is being elaborated by TUEV Sarbrüecken, Germany, and will be presumably finished on schedule end of April 2010. As yet, the results can roughly be resumed as follows (please note: binding statements can only be derived from the future report):

Almost all CNG1 tanks are made of the quenched and tempered steel 34CrMo4. This material is in principle suited for gases containing hydrogen, even for pure hydrogen.

The suitability of this material depends however on the parameters • yield strength (suited below a limit value),• hardness, and (suited below a limit value),• inner surface quality (roughness, surface must be specially finished).

CNG Type I tanks with very high strength 34CrMo4 steels - used for weight optimized automotive tanks – can not be applied for H2 admixture. Whereas, Type IV cylinders with advanced plastic liners with low H2 permeation rates are a feasible solution to overcome the embrittlement problems of high strength steel cylinders. In the INGAS hybrid vessels, a metal boss is applied. Due to the specific sealing concept of Xperion, the sealing is realized directly between the plastic liner and the valve body. Thus, the boss is not directly exposed to the gas and protected regarding hydrogen embrittlement.



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BACK-UP



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SP-B1 “Gas storage for CNG engines”

Today’s NG vehicles InGas

Gas composition G20 (100% CH4) ÷ G25 (14% inert as N2)

Matrix of limit gases defined within SP-B0

Fuel flexibility Homologation with G20 and G25 Full compatibility with commercial NG +Biomethane + NG / H2 blends (up to 20-30% by volume)

D Tank mass / vehicle range

+ 150 kg/350 km (steel)+ 200 kg/500 km (steel)

+ 160 kg/500 km (composite)

Vehicle range 250 (bifuel) ÷ 400 km (monofuel) 500 km (monofuel)

Vehicle capacity via a specific architecture adopting a not intrusive tank location

Just adaptation to the pre-existing gasoline vehicle

Vehicle trunk capacity reduction not higher than 10%

CH4 conversion efficiency at a given catalyst cost

80% < on 100.000 km durability > 90% on 160.000 km with possible lower catalyst cost

Fun-to-drive (expressed by torque output)

12% less than the corresponding NA gasoline engine vehicle or equivalent in case of boosted engines

Equivalent to the corresponding 2006 diesel vehicle



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Prototype demonstrator and virtual vehicle studyPr

otot

ype

dem

onst

rato

rVirtual vehicle study

Tasks for 2010 and 2011

WP B1.4 Storage Module Concepts

WP B1.5 Advanced CNG Vehicle Concepts

Activity without

WP B1.4 Storage Module Concepts

WP B1.5 Advanced CNG Vehicle Concepts

Vessels will be developed in according with ECE R110 without further constraints deriving from safety

XPERION and VENTREX would have to supply to C.R.F. the components (vessels, valves, etc)

Virtual analysis* + study of realisation feasibility

Vessels will be developed in according with ECE R110 and further constraints deriving from vehicle performances and safety and based on indications provide by the expert partners

Vehicle

Specifications and requirements

Prototype demonstrator

Virtual vehicle study

Vehicle type 3/5 door hatchback

Vehicle platform "C" "B"

Vehicle kerb mass [kg] 1460 1260

Vehicle range [km] <= 500 500

CNG storage system mass [kg] 130 120

Emission CO on NEDC cycle [g/km] 125 115

Fuel consumption [kg/100 km] 4,75 4,2

Fuel mass [kg] 24 (G20) 21 (G20)

145 at 200 bar 130 at 200 bar Tank capacity [l] 130 at 260 bar 110 at 260 bar

Engine type 1.4 litres / 4 cyl / TC Multiair / CNG

Max Torque Output ~ 220 Nm @ < 2000 rpm

Max Power Output ~ 100 kW @ 5000 rpm

Max CNG engine fuel consumption [kg/h] ~ 24 (G20)

CNG engine fuel consumption @ idle [kg/h] ~ 0.5



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Torsion beam axle (Baseline)

Torsion beam axle (Optimised)

Task B1.4.1: Optimization of vessel lay-out (Target = 130 l)



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CRF design domain

Task B1.4.1: Valves – CRF Design domain



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CRF proposes neck mounting for Virtual vehicle studySection A-A

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65

40

65 2”

Section A-A

CRF design domain

Task B1.4.1: Cylinder mountings – CRF Design domain

Objectives for the development of advanced automotive CNG storage system and vehicle concepts :

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