MAXfill CNG trailer filling solution

Eclipse has designed a filling system which significantly increases CNG Trailer usable

capacity by utilising existing station components and integrating our Cold fill controller valve

THE ISSUE Trailers filled with gas to MAWP of the cylinders suffer from heat of compression and

when leaving the compressor mother station are at a temperature higher than

ambient from 15-40 degC depending on fill times and equipment used. After

transport to the decanting site there can be as much as a 20% reduction in capacity

as the gas temperature has had time to settle.

Type 3 and 4 trailers this can be exacerbated due to the insulating effects of the

cylinder construction.

THE CAUSE A combination of station factors cause the gas to heat which when it cools reduces the trailer

capacity High Ambient temperatures

Time of day

No cover on the trailer tubes

Poor Pipe-design

Poor Compressor HX design

High fill speed

CNG trailer leaves the depot with a trailer full of hot Gas CNG trailer Arrives with reduced payload of cool gas

The capacity can be reduced by as much as 20%

THE SOLUTION

Remove the heat from the Gas!

Current solutions on the market is to use are to install large refrigeration systems to cool the

gas. This, in our opinion, is an expensive and high energy use solution.

Eclipse has developed retrofitable technology to significantly reduce the gas temperature

HOW IT WORKS

Natural Gas cools when subjected to pressure drop (Joule Thompson effect)

The Eclipse MAXfill cold filling system uses the technology of the existing CNG system and

integrates its cold fill control valve to act in a similar fashion to a refrigeration system.

When the trailer is empty the Cold fill controller is configured to utilise the

compressor cooling in conjunction with system sizing parameters to create colder

gas filling the trailers. As the trailer is filled the cooling reduces but the overall goal

is to fill the trailer close to its rated capacity and as close to Ambient air temperature

as possible. Generally the final filled temperature is within 5deg C of ambient

Compressor

Expansion Valve

Heat Exchanger

Closed Loop

refrigeration system

CNG

Compressor

Cold fill Controller

Evaporator

Eclipse Cold fill system

TECHNOLOGY

VFN-160 1” NPT Pilot operated Cold Fill Controller Valve

Bi Directional cooling on filling full flow on decant. Ideal solution for large capacity

trailer cylinders

APPLICATION

Large type 3-4 cylinders

Type 3 and 4 cylinder construction creates an insulating effect which reduces the

ability of heat to escape from the cylinder when filling through the walls of the

cylinder. Additionally the capacity of large type 3 and four trailers is double if not

triple the capacity of a type 1 steel trailer

The VFN-160 valve is designed to be installed on CNG trailers to ensure full

efficient flow to cylinder banks in each direction. Cooling the gas on filling and

high flow on decanting

Rated

5000psi

345BarG

CV

15.5

-45C

+85C

Thread size

1” NPT

-8SAE

Two-way

VPN-1612-DL 1” NPT Pilot operated Cold Fill Controller Valve

Ideal solution for trailer fill post solutions filling high volume cylinder trailers

APPLICATION

Steel trailers CNG Trailers with multiple tubes.

As steel trailers surface temperatures conduct and radiate heat the VPBN-1612DL

regulator is the ideal solution for these installations.

CONFIGURATION

The cold fill controller requires a pilot pressure to maintain its set point. Depending on

the site or trailer installation will determine the piping configuration of the pilot

Eclipse has developed a temperature compensating system which enables the

daytime fill pressure to be higher than at night

Rated

5000psi

345Bar

G

CV

9.5

-45C

+85C

Thread size

1” NPT

-8SAE

One-way

CASE STUDY

S.E. Asian Installation

Our S.E. Asian client installed Cold fill controller solutions into

their filling station.

THE RESULTS

Data was taken before and after the controllers were installed

CONCLUSIONS

The table of results showcase that the system increased the capacity experiencing a rise

between 12% and 20%. As the test site was on the extreme side of operating temperatures

the results were as expected and with some fine tuning the site will improve its overall fill

capacity

Cylinders 40Ft 12 tube type 1

Trailer G23 Trailer G-16 Trailer #G14

Before After Before After Before After

Cylinder WL

26,640

26,640

26,640

26,640

26,640

26,640

Density(kgm3) 0.74 0.74 0.74 0.74 0.74 0.74

Pressure initial (Bar) 35 30 40 30 40 30

Pressure Final (Bar) 250 250 250 250 250 250

Final fill volume M3 6052 6994 6061 7371 6248 7075

Gas Temp final Deg C 51.5 43.0 48.8 40.1 40.3 39.4

When Filled Night Day Night Day Night Day

Ambient Temp Deg C 27 37 26 36 26.0 35.0

Gas / Ambient Temp D 24.5 6.0 22.8 4.1 14.3 4.4

Additional M3 % Additional M3 % Additional M3 %

942 13% 1310 18% 827 12%

ABOUT US

CNG Bio-CNG

Alt Fuels

Eclipse valves engineers have been designing

valves and technology for alternative fuel

systems since the 1970s being instrumental in

the development of technology which is used

now in almost every CNG station around the

world.

Eclipse along with its sister company’s Bison

Compression and Artic Cryogenics have

developed a modern range of technically

advanced systems for a wide range of Alternative

fuels applications improving efficiency and

accessibility to new markets.

LOCATION

Eclipse Valves and Fittings

113 North Road Clevedon Auckland New

Zealand 2582

Phone +6492929115

email sales@eclipsevalves.com

web www.eclipsevalves.com