Installation Tips for Reducing Gas Generator Set Maintenance Costs

by Contributor KelscNM on ‎09-29-2010 12:23 PM

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Often, serviceability can be overlooked when doing detailed design work for a gas genset installation. Here are some simple ideas for gas power plant design that have the potential to reduce maintenance costs, increase uptime, and reduce overall life cycle costs.

Ask your manufacturer or supplier if these strategies can be used at your site, either before or after genset installation.

1. Match the capacity of your bulk oil storage tank to the size of the oil delivery truck to reduce the cost of delivered oil.

2. Match the size of the oil makeup tank to oil consumption. For example, a 1,600 kW genset could have approximately 140 gallons of oil capacity with a fill indication at 30 gallons below full. If the mid-life oil consumption is 6.2 gallons a day, you’d top off every 4-5 days. By installing a 150 gallon lube oil makeup tank, the oil top off interval would be monthly, saving technician labor.

3. Overhead lifting capability can save money by reducing labor hours – especially when it comes to larger gensets. Using the same example as above, over the course of 20 years, overhaul work will require an estimated 1,500 labor hours. An on-site hoist might reduce the labor commitment by up to 20 percent, or 300 hours for one engine.

4. Pre-install ports and sensors for emissions and O2 readings in your exhaust piping to reduce the time associated with taking readings.

5. Meter and record the total coolant drain volume when changing coolant. Use this information to fill the exact amount every time, preventing spills.

6. Install quick connect/disconnect mechanism for faster oil and filter changes.

7. Consider a compressed air engine starter and hard wired 24V DC connection to remove the cost and hazards of battery maintenance.

8. Besides scheduled oil analysis, a gas fuel analysis prior to installation provides a baseline sample of your fuel composition and contaminants. Regular gas sampling might also be included in a maintenance program, particularly for low energy applications such as landfill or biogas or if your engine is experiencing detonation.

These are just eight ideas that you can apply to your gas genset installation to extend genset serviceability and reduce costs. These suggestions may nor may not apply to all installations depending on the size of genset package, application, hours of operation, etc. Also, this list is far from complete.

- Have you or your service provider tried any of the above suggestions? What is your experience?
- What are your ideas to make genset service more efficient?
- Have you ever seen your engine go into detonation (knock) due to a change in fuel composition?
- How often do you test your fuel composition and make engine adjustments?

Please post your thoughts below.

Comments
by New member jospower
on ‎10-06-2010 09:03 AM

Load testing is another expense. New NFPA rules require monthly load testing for some installations. I've heard of a permanently installed load tester that connects to the grid and doesn't use resistors. Is this cost effective (it's definitely green, since the power isn't being burned in a resistor)

by Visitor markslum
on ‎10-06-2010 11:11 AM

Very helpful post.   I've also seen some successful combustion catalyst system that reduces fuel consumption and lower emissions in diesel engines.

 

www.wpowerproducts.com

by Visitor rjhintz
on ‎10-06-2010 11:18 AM

This is a really useful topic, but I have some questions as someone who deals with generators from a distance, so to speak, in a data center design capacity.

 

I thought I understood elementary terminology, but apparently not.  In speaking of "gas" gensets, I assume, perhaps wrongly, that most or all of this applies to diesel fueled gensets, right?  When I hear "gas," I think natural gas, which is a fuel choice, as I understand it, but that isn't the context here.  The overhead lift capability is independent of fuel, I assume.

 

#1, Matching size of oil storage (fuel oil, right?) to the oil delivery truck would seem to be dependent on the supplier, which could vary by contract, I suppose, unless there's a best practice, "one sizes fits all" strategy that mostly works, regardless of who the supplier is.  In a typical installation, is there a percent of cost add-on for matching the size of oil storage?  That is, perhaps matching size adds 1%, or 2%, or X% to the one time installation cost, or perhaps it doesn't add anything.

 

#2, Matching size of makeup tank: what's the strategy for generators used for standby?  Usually there's little or no consumption, except for testing.  However, in an outage situate, the generator runs essentially constantly.

 

#3, Overhead lift: understanding that every site is somewhat different, how much does adding overhead lift typicall add?  Is this $1K, $10K, $25K add on?

 

#4-6: typical add on cost?

 

#7, add on cost?  What are disadvantages to this?

 

#8, typical added costs?

 

Thanks for starting this topic and any clarifying answers.

 

 

 

 

by New member pumpprincess
on ‎10-06-2010 11:58 AM

Install a prelube system or a dc backup prelube system from VARNA Products!

 

Money saving, increasing equipment life and reliability smiles 2 share ;-)

by Contributor KelscNM
on ‎10-11-2010 09:18 AM
Responses to rjhintz's questions:

I thought I understood elementary terminology, but apparently not. In speaking of "gas" gensets, I assume, perhaps wrongly, that most or all of this applies to diesel fueled gensets, right?
Engine manufacturers and genset packages commonly refer to diesel fueled gensets as diesel gensets, and gaseous fueled gensets as gas gensets.

When I hear "gas," I think natural gas, which is a fuel choice, as I understand it, but that isn't the context here. The overhead lift capability is independent of fuel, I assume.
Yes. Many of these recommendations could apply to either diesel or gas fuel gensets, but they are targeted more towards prime power or continuous power applications where the engines are running thousands of hours per year, versus 20-100 hours per year in the case of an emergency standby installation.


#1, Matching size of oil storage (fuel oil, right?) to the oil delivery truck would seem to be dependent on the supplier, which could vary by contract, I suppose, unless there's a best practice, "one sizes fits all" strategy that mostly works, regardless of who the supplier is. In a typical installation, is there a percent of cost add-on for matching the size of oil storage? That is, perhaps matching size adds 1%, or 2%, or X% to the one time installation cost, or perhaps it doesn't add anything.
No. The intention here was to reference the lubricating oil storage for a prime power application. These packages consume oil as part of normal operation, and also require regular oil changes based on operating hours. If the typical prime power diesel genset requires oil changes every 500 hours, and a gas package requires oil changes every 1000-2000 hours, then oil becomes a very regular consumable. Oil change quantities for larger (>1000kW) genset packages operating continuously are in the hundreds of gallons of oil, and oil consumption quantities are in the dozens of gallons of oil per week.

#2, Matching size of makeup tank: what's the strategy for generators used for standby? Usually there's little or no consumption, except for testing. However, in an outage situate, the generator runs essentially constantly.
No benefit for standby operation.

#3, Overhead lift: understanding that every site is somewhat different, how much does adding overhead lift typicall add? Is this $1K, $10K, $25K add on?
It is a significant investment that would be in the 10's of thousands of dollars. Again, this recommendation would not apply to standby applications where you run very limited hours per year.

#4-6: typical add on cost?
#4 - Estimate a few hundred dollars, plus a couple hours of service labor.
#5 - No additional cost if conducted as part of routine maintenance.
#6 - Estimate a few thousand dollars for a larger (>1000kW) package


#7, add on cost? What are disadvantages to this?
Assume costs slightly higher than those of an electric start system. There are no significant disadvantages other than the need to monitor and perform maintenance on an air system.

#8, typical added costs?
These can vary depending on the analysis provider and the type of fuel analysis. Estimate several hundreds to a thousand dollars.


Great feedback everyone, keep it coming.

--Nick
by Super Contributor
on ‎10-12-2010 09:23 PM

Before construction review design of piping and support systems with service in mind.  Things like high point vents and low point drains seems small, but when you spend hours trying to vent a cooling system it really wasn't that much extra cost. Pipe supports also seem like good ideas to mechanical contractor until a technician points out it blocks access to a service point.

 

On gas engines. always provide fuel filters with gauges for monitoring, "clean dry" gas supplied by utility may not be clean and dry. Make sure an operable valve with ability to lockout is installed, a cheap plug valve that needs a 4 foot wrench to close will likely end up being a problem.

 

Make sure cooling system have points to draw coolant samples and to add chemicals, prime power systems need regular cooling system maintenance, even with ELC.

 

Review access, look at piping runs for coolant, air and exhaust, seen lots of sites that required partial disassembly of exhaust system to pull pistons and liners.  Make sure spool pieces are in piping that will need removal for service, taking down a 20 foot section of pipe for 3 feet of access will cost many times over in life of a plant.  Same thing with coolant lines, make sure a pump can be serviced, preferably without draining entire system by proper use of isolation valves.

 

If you add a hoist, make sure you know what it's going to be used for and it's limitations, a 1000lb hoist would be great for most parts but assure someone down the line doesn't overload it and do structural damage or hurt someone (seen that more than once).

 

Make sure things like service air, water and electrical outlets are near where the work gets done, not only the engine but things like heat exchangers need cleaning too. Adds time and risk if the service tech has to run a cord or air line 100'.

 

Good work lighting improves repair process, bad lighting invites something being missed.

 

Make sure access for major repairs is considered, like access to side of block for bearing inspection/replacement.

 

Consider some worst case possiblities, like getting a crank out, how will it be done and is there room for it?  Same thing for the tail end, in a prime power site likelyhood of tail end needing shop service is high.  Are the conduits not in the way?  Can you get it out without removing entire package, etc.

 

Consider relocating junction boxes, gauge panels and some sensors away from service areas of engine, trying to do a valve adjustment around a gauge panel usually results in extra time needed, and in some cases a mistake that can cause an engine failure. Remember the factory installs these items close to the engine for their convienence, not yours.

 

Consider the area around the engine for dealing with removed and new parts, and possible risks to personel handling those parts, most everything is heavy, so maybe a bit of extra clearence or an effort to make sure the surrounding area is level for safe working is worth review? I once had a designer argue the point with me, I gave him a 50 lb bag of sand and told him to walk around the engine then out of the enclosure, he got the point.

 

Modern gas engines require a fairly large DC power source for controls and ignition, so just eliminating starting batteries may not always eliminate the need for batteries at all.  Air start systems have their own issues, depending on starting requirements and ambient conditions.  Frankly I've found long term maintenance costs for air start systems more than costs for DC systems on 3400 and 3500 series engines.  Going to turbine starters is usually better than vane type, but air storage and piping still an issue, as is the compressor. Funny how many air starters I've rebuilt over the years because someone didn't add oil to the lubricator.

 

Make sure Lock Out Tag Out can be safely and quickly done when needed, major repairs require assurance that the engine cannot turn uncontrolled, means the start method needs disabled and the breaker needs to be racked out or isolated.  Need to make sure the design and operating procedures support doing this right when needed.  What is cost of having unit down and a bunch of techs standing around because the breaker can't be racked out due to many possible reasons? Also know where circuits that feed heaters, pumps and other support equipment are, and how to make them safe as well.

by Visitor pervin
on ‎12-21-2010 11:17 AM

All great tips Nick,

Many of the LFG projects I managed didn't have running water at the sites. This can be a big issue with respect to service and routine operations. I always wondered why someone would go to all the expense of renting port a pottys and the like and not consider installing a low cost item like a water main. Especially when you are constanstly trenching and installing plastic piping in the landfill itself. Go figure.

by New member vondanikken
on ‎01-30-2013 10:13 AM

This is an excellent post, installing these can be a pain, we at National Power Supply appreciate posts like this so we can pass this valuable information along to our customers.

by Vincent Scatena
on ‎04-02-2015 05:01 PM

This is a good article, though also depending on industry there are some other tricks on reducing maintenance costs.

 

I know in aggregate, and mining especially, well serviced and sealed "weather protection" and containers can dramatically reduce maintenance by reducing particulates.  I saw some good options on Industrial Motor Power.

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