Combined Heat and Power – Lovson Air Compressor

Is this the basis from which you can build a legal CHP power plant? You be the judge….

If you are making the time to read this, you likely know that combined heat and power WAS the standard in industry before the UK and America were electrified. Companies that produced machines and other durable goods often had CHP built into their factories, and many were elaborate and well thought out. Many of these plants were still functioning and in good shape when they were turned down and there are now efforts in UK and America to preserve some of this amazingly well engineered equipment.

As we look to the future, there is a lot of interest in distributed power generation, there’s a vision that small power plants could be established on and off the grid and they could have multiple power inputs as well, Wind, Solar, Bio Fueled or Natural Gas low emission engines running dynamos, and of course hydro. In places like Montana and Wyoming, there are billions of cubic feet of clean natural gas waiting to take the place of fuels that create more emissions. Is it possible that we can generate power at the well head and put it onto the grid versus build pipe lines to bring it to the markets and power plants?

As for us DIYers and Off Griders, we have always been interested in small power generation for various reasons, and these power plants are part of our focus.

I’m currently looking at one engine that LOVSON Markets, they refer to it as a LG6 or LG8, others will know th design as the GM90, this one capable of close to 6KW at the shaft.  If we reclaim waste heat from the coolant and exhaust, this could be a good choice for small power CHP. The engine looks well suited for spark conversion but what draws my attention to this engine is reports from the third world that this variant is delivering great fuel economy and longevity. Most noteworthy, the engine is delivered clean, and there’s been a lot of engines that have already racked up 6000 or more hours with no break downs.

I have used JB Shah as a source of information for the history of Indian engine building and I have found him to be one of the best sources in all of India to run down components and more. One impressive feat was JB Shah arranged to have custom bearing shells made for our DIYer CHP experiments group, and I can tell you that no other contact there seemed to have a clue how to get it done. JB set up the deal and had them sent to us right away.

With all said, the LG engine is one of the engines I’d consider for CHP as it will likely outlive other small diesels and is designed to rebuild in place. This engine differs from the  from the Standard CS type, and you should note that many parts are not interchangeable, so consider stocking the unique parts, or knowing who stocks them. the engine does use a DI head and piston, and there are claims of about 10% more efficiency and I have heard reports that these engines are favored at higher elevations as they make more power. there are a number of parts that interchange, the idler shaft is a standard part, I fitted a standard ring in the bore, and the ring gap looked correct. the head gasket is different than a standard CS, intake and exhaust fittings are standard, the idler gear is smaller, there is a piston pump that assures oil pressure to the all important crank pin, and this may cure the problems we’ve seen in the Standard clones with what looks like an oil film break down on the upper crankpin shell >possibly< caused by the position of the oil feed hole and the fact it’s right in the middle of the highest load area of the upper shell?

You may have read that the LG has been used as an Air Compressor and that these are legal to import. There is also a selected parts kit that can be ordered to convert this engine to a diesel engine. Should you decide to construct a combined Heat and power plant to be run on biofuel, you’ll need to research present EPA law and make sure you fully comply, I hope to share more information on this soon, as I hear the EPA is working with researchers and those who construct CHP plants.

There are many ways to design a power plant, but careful work to identify your peak power need can help you design the right plant for your needs, if you run less RPM (within the design limits of the engine) you can load these power strokes to a higher percentage of load and in theory raise the overall efficiency of your power plant and lower emissions. Currently, there are over the road engines that are burning more fuel in order to produce less emissions in certain categories of emissions. A study of the pre and post injections made in modern diesels could be an interesting study, I have been told that the maximum amount of work can be done for the least amount of fuel using one injection per cycle, and for those who believe that real and total emissions has everything to do with burning less fuel, this causes us to scratch our heads. We live in a time when political science and propaganda are more powerful than hard sciences, so what to believe?

Particle size in emissions is another interesting topic, some suggest that higher emissions standards in diesels has forced the use of higher injection pressures that are partially responsible for creating a smaller soot particles that is far more a health hazard. What ever the case, we have room in the stationary CHP plant to devote as much room as necessary to trapping these partials.

As for our first prototype, we may not run it for some time, our first assessments have everything to do with cost and getting it down where there is a chance for some kind of return on investment, those who recognize the huge economies of scale the power company has will be more motivated by backup potential or off grid potential, the pursuit of getting the highest efficiency and lowest emissions possible through experimentation is a popular goal in our DIYer and CHP experimenter groups.

We received the Lovson Air compressor and noted the shipping box was constructed of metal and composite materials to assure there was no wood products full of bugs or pests that customs or Agriculture people would stop the import of. What I received was a crate designed to take a direct hit by a nuke and survive! Overkill and expensive to build, there’s about 45 feet of heavy angle iron used in the crate frame! And then dozens of nicely plated nuts and bolts to hang the composite panels, the engine is bolted to two metal skids that bolts to the fully welded and rust proofed crate frame. I think an American outfit would charge a fortune for the crate alone! The point? We need to help India get the cost of the crate down, but in order to do that, we need to know a lot about customs and how they might inspect a container load, or a single crate.

Above: Here’s a mount I’ve found works well with the Utterpower PMGs

the frame is built like a ladder using thick wall materials and fully welding top bottom and sides. The hinge plate is sued because we’ve found the PMGs run very well on them, and one can use a tension spring for proper tension, and also pull the rod from the hinge for quickest removal of the head to gain access to engine door for rebuild or other maintenance.

Above: Utterpower 3KW continuous rated PMG can easily crank out 4.2 KW. The hinge plate makes removing the generator from the frame a 30 second operation, just pull the rod, it’s also easy to ‘fab up’ with a wire feed welder.

Above: Most folks who run CHP units for efficiency establish accurate timing marks. this done by finding .005″ either side of TDC and then finding the middle. The pointer is temporary, permanent marks will be transferred to the other flywheel when done.

Above:  Here’s a neat laser level with a fairly accurate digital ‘degree’ wheel built in. Once you have TDC, tape a device like this on firmly and close to ‘Zero” degrees, then simply push the button to zero, and then turn the wheel to find your marks. I like to establish TDC, 20 degrees BFTDC, and on this engine, 40BFTDC is a handy reference, because at this point, it’s easy to slip in the idler gear. Counter weights and other stuff is in the way if you attempt to do this at TDC. Of course, 20BFTDC is reference for your spill timing, something discussed in the utterpower CD. don’t have one of these fancy levels? simply measure circumference and divide by 360, then multiply by number of degrees you want to mark off.

One trick is figuring out the best way to get the gear train in time. I use what I call 20/20 method, it’s easy to remember and if you established the 20BFTDC mark as most serious CHP builders will, you can use that mark. When you slip in the cam, make sure the injection pump lobe center is pointing at 10 O’clock AND that the flywheel is positioned at 20BFTDC. Verify your work by measuring that the Intake valve is about .020″ off it’s seat when the flywheel is at 20BFTDC. there is more info about timing the gears on the CD and likely elsewhere on the WEB.

Extracting heat from the exhaust system, what might we do?

Many of us have read about the problems created when we condense these gasses, some report that stainless steel doesn’t last forever in sections of a condensing exhaust system. The new over the road partial trap used in production diesel pickups in 2007 uses a lot of energy to literally incinerate small carbon particles that eventually create excessive restriction to exhaust gas flow. In a Stationary CHP plant, we have more room and thus more options and maybe some ideas could be used in over the road applications too. Example?:  The the diesel pickup truck, in northern latitudes.. we won’t wait till the particle trap if restricted, we make use of a demand for heat to clean the trap. We all know how nice those seats are with the electric heaters because a diesel is a little slow in making heat for the cab and defrosters on startup, why not use that period of demand for heat to clean the particle trap and recover a little of the heat and direct it into the defrosters and cab? Remember the gas heaters in VW busses in the 60s-70s?

Another thing I think about are the simple humidifier systems where a piece of cloth runs between two rollers, one is in the bottom of a water tank, the other roller is high and the air stream is directed thru the fabric to evaporate the water and then directed into a room where we want the moisture. What kind of particle trap could we make with this principle? What kind of solution (like soapy water) could we have in the bottom to trap these carbon particles and what other objectionable things in the exhaust stream could we remove with it?

More to follow, watch as we fit this CHP rig with heat exchangers which will carry reclaimed heat from both the exhaust and coolant to a heat storage tank. In order to meet our KISS philosophy and avoid the reported failures of active circulation elements, we will design both exchangers to thermal siphon to the main storage tank. From there the heat is pumped to a point of use using a 1/20HP cartridge circulation pump.

How to Order: You can order the LG series air compressors now.  Lovson has developed a CD that shows you how to convert this air compressor to a diesel engine and the CD is free with the purchase of an air compressor. Please note, you’ll need what Lovson calls the ‘selected parts kit’ which has virtually everything you need to build your engine in about 45 minutes if you have the basic mechanicals skills, longer if you haven’t been around a wrench or hammer for a while. To order: email Joanna@lovson.net

Remember you can import up to $2000 worth of goods yourself.  Check the US Customs website for more information.