Biggest CNG injector in the market? 2

[Azmio]

I am having a tough time to find the biggest CNG injector. I figure out that the biggest CNG injector can either be for truck or industrial applications. Is there anyone out there that can help me out in term of maximum flow and the injector dimension.

 

[TStaples]

Azmio,

CNG injectors used on pickups are typically higher in flow than the ones used on most industrial apps such as forklifts.

I formerly was the Engineering Manager for Quantum Technologies. They produce a CNG port injector that is suitable for CNG. It is used on many CNG V-8 pickup truck engines. It is the 2nd highest static flow rate CNG/Propane Injector that is commercially available. The highest comes from Keihin in Japan, but you generally cannot purchase it unless you are an OEM level company. The Quantum injector is about 5% lower flow than the highest flow Keihin variant. The Quantum injector is readily available. If you are an OEM level customer, then contact them directly.

http://www.qtww.com

If you are not an OEM level customer with high volume purchasing requirements, then they are represented by RC Engineering.

http://www.rceng.com

RC Eng. will handle all of your supply/information requirements for low volumes/prototype volumes. The Quantum part number for a CNG/Propane injector (same injector, used at different pressures) is 100078.



-Tony Staples

http://www.tscombustion.com

 

[pipehead]

Trains in California must use natural gas, so I'd suspect they are big, if they use injectors.

I operate 4400 HP natural gas engines manufactured by Catapillar. There are some newer 8000+ HP engines from Wautzila (sic) from Swenden. These units don't have injectors.

 

[Azmio]

guys,

thanks a lot for the information. I am looking for a CNG DI injector which is big enough to supply the gas in a very short amount of time. Gosh, you'd be surprise on how much time available at higher rpm.

I can add 2 injectors but I would rather have 1 big one instead of 2 small ones. I appreciate any help that I can have.

 

[pipehead]

I don't think you can find one big enough because of gas density, the injection port maybe 1-1/2" and if you have 2 3/8" ports they would be too small, unless you have 100 psig gas to inject (with CNG yes). Pulsing a valve in gas service will be difficult because of the acceleration and sudden pressure drop at the inlet to the injector. I suppose this is why big industrial engines do not direct inject CNG.

 

[Azmio]

that's why I am posting it here.

The sudden pressure drop at the inlet can be minimized if you have sufficient size gas rail before the injector.

As for my gas rail pressure, it is around 10-20 bar.

 

[Fabrico]

Have you looked into using some type of Diesel injector?

 

[TStaples]

Azmio,

Do you mean DI - Direct Injection, or PFI - Port Fuel Injection. The injectors I mentioned in my previous post are all Port injectors. With the exception of other products that might be in development somewhere and not publically announced, I am only aware of one DI CNG injector; Westport Innovations.

http://www.westport.com/tech/enable.php#injectors

Diesel Injectors won't work, as they are designed for much higher pressures, of a much more dense liquid fuel, and have very small annular flow passageways through the injectors. Plus, they rely on the diesel fuel to lubricate their innards. CNG requires a design specifically for CNG. The only CNG injector manufacturers I'm aware of are:

Westport - DI

Quantum - Port

Keihin - Port

Bosch - Port. Not really a CNG injector. Bosch actually sells a Methanol Racing Injector (i.e. Indy Cars and such, based on the original EV1 outline), that several companies have attempted to use as a CNG injector. It has almost as much flow capacity as the Quantum. I know of two very large Detroit based OEM's who have lost 7 figures warranty dollars replacing those things becuase they gum up rather quickly in service. CNG has a lot of "crap" that comes along with it in actual use (compressor oils, water, rust, etc . . ..)

Siemens - Port. On again, off again in development. The last I heard was it was working, but the durability was not anywhere near what it needed to be. Small package size, but about 2/3 the flow capacity of the Quantum, based on numbers given to me by my former customers who were also evaluating them. Availabilty unknown.

Teleflex GFI - Purchased the AutoGas group in Belgium. They supposedly manufacture an injector in partnership with what used to SAGEM Automotive. I believe it's been folded into VALEO now. It's a side feed design with a barb fitting on a plastic housing. It looks more like an EGR valve in cross section than an injector. It seems to work, but no OEM's will go near it as it could easily crack in an accident, which could lead to a thermal event.

Zenith Fuel Systems - Industial Market. They sell an "injector" which is really a throttle body with some metering solenoids. OK for a forklift truck (low power) but not going to work for a higher power engine.

Clean Air Power - They sell some stuff for heavy duty trucks, but their injectors (the ones I've tested) don't have sufficient flow capacity at 50 psi delta to fuel an engine. They work fiarly well from 125 psi on up. However, most OEM's I've dealt with didn't like the fact that they could not drain their compressed storage tanks down nearly as far with the CAP system, effectively cutting vehicle range. If that isn't a limitation for you, then their system might be worth investigation. I have no idea if they have durability issues.

I've heard of a couple of other Mom and Pops, but have never seen any actual hardware that worked. I've never heard of Delphi, Marelli, Denso, or Aisan having anything for the CNG sector, but it's possible that something is just coming to market.

If you find something new, please post it here. Up until very recently, I worked at ground zero of that industry. I like to stay current.

-Tony Staples

http://www.tscombustion.com

 

[Lou Scannon]

FYI, Bosch has been selling a line of CNG port injectors as "CNG Injectors" to OEMs and Tier 1 suppliers for the past 10-12 years. They are very cautious about selling them, since, as you say they are based on liquid injectors and are subject to the problems you mention. It is possible to clean the contamination with solvent, but Bosch does not endorse any such maintenance procedure. Bosch is becoming very bullish on natural gas for the upcoming decade, and they are rolling out a second generation line of dedicated design CNG injectors later this year in the current compact automotive external package. These are designed to be much more tolerant of contamination, but I think Bosch will continue to be cautious about who gets them.

For more information, try contacting
Andrew Wagner
Senior Sales Engineer
Powersports & Small Engine Controls, Powertrain Division
andrew.wagner@us.bosch.com
(248)876-2992

 

[Azmio]

I have a presentation slides from Bosch. They have this NGI2 CNG DI injector. it's really small if compared to others but it's limited to 500cc per cylinder displacement.

I went through papers from Nissan and they have this CNG DI injector for 1.15 liter per cylinder. However, I have no clue on the technical specifications of the injector. Could it be from Denso?

See, when you have a CNG DI, the key in fuel economy is stratified charge. With the currently available injector, I wonder how stratified can we get.

Any help would be greatly appreciated. Thanks guys!

 

[turbocohen]

Quote:"Siemens - Port. On again, off again in development. The last I heard was it was working, but the durability was not anywhere near what it needed to be. Small package size, but about 2/3 the flow capacity of the Quantum, based on numbers given to me by my former customers who were also evaluating them. Availabilty unknown." Unquote.

Er.. uh Tony.. atchooly the siemens cng injector is available over the parts counter in the EU from some major oem's.. it was in development for a decade and entered production after the turn of the decade... bout .5 million served so far.
The magnetic circuit dna is shared with a DI injector. It unofficially demonstrated DI capability WELL above 20bar using a 42v peak/hold strategy on a Xler 2.4L student research DI project long before regular production using a custom wound coil. No trouble up to 5K rpm. Built em one-off intended for a canadian sae competition vehicle.

Durability and contamination tolerance are issues for all brands. The main problem is fuel contamination amplified by poorly designed fuel handling systems that coalesce aerosols and deposit sulphur laden oily residues on the injector innards. Real world durability validation and competitive analysis are very subjective so take my word with a grain of salt.. the siemens port cng has higher dynamic operating pressure capability and contamination tolerance than the others mentioned.

Just my 0.02 dinars, turbo

 

[TStaples]

Turbo,

Thanks for the information! I'm not familiar with a DI package style available in Europe. That's good to know. That would have been done out of Pisa Italy. The Siemens CNG injector I'm familiar with was requested originally by Ford, to replace the Bosch Methanol Racing injector on certain CNG programs (like the CNG Crown Vic in the US.) Siemens worked on a variant of the Deka IV top feed package out of their Newport News, VA facility. I last saw those at Ford in 2001. Perhaps that project died, as I never saw hardware that was even approaching production readiness.

-Tony Staples

http://www.tscombustion.com

 

[turbocohen]

Tony,

Deka CNG is not available as a DI injector to the public, about a dozen were built and there is an SAE paper or two referencing them so it is in the public domain somewhere. They are offered as a port style only and are still mfg'd in Newport News.
It was originally an engineering excercise to support the NGV Challenge sponsored by GM and SAE with unofficial support from JTE. Early deka IV based injectors were built exclusively for GM sponsored student teams. The production versions with DI dna and contamination tolerance were first tested by a guy from JTE. Later on after most of the refinements were made they were tested on Fords. Every major oem in the world has tested them and every major oem suppliers cng injectors have been benchmarked for performance and durability.

Regards, Turbo

 

[CNGBrick]

You may want to contact Alternative Fuel Systems in Calgary Canada.

They manufacture high-flow port injectors for automotive applications (100 HP continuous flow at 5.5 bar inlet pressure) and also make an injector suitable for stationary engine applications (about 1200 HP worth of gas in continuous flow at 4 bar inlet pressure).