Stirling Engines

5/6/24:

PDF file of the NASA Stirling Engine test on a delivery truck.

If this engine just charged a battery pack, and if the battery pack was much smaller, you might have a winner. The set up would be a series hybrid that charged a battery pack with about 45 mile range. You'd have the option of having it charged at home, or work; or you'd just run the Stirling engine when necessary for a re-charge of the battery as needed. That would work like the Chevy Volt set up. Range anxiety would be a thing of the past. Just fill up like with an ICE.

The Volt has not been popular, and may not be available anymore. Why not? That's beyond the scope here.

Electric engines are getting smaller and more efficient. So the weight of the thing should be less than a battery-only Tesla-like set up. Not only electric engines getting smaller and more efficient, so are batteries. But even with those improvements, batteries are too heavy and expensive.

end update of 12/08/23 post:

12/08/23: Update to last post of 10/22/21:

Automakers turning to hybrids?

Actually, they could turn to Stirling Engines, or better yet, Stirling/Electric hybrids. The two types should complement each other nicely. Stirlings take awhile to warm up. A charged battery is ready to go. The Stirling can keep the battery charged, and end range anxiety.

Batteries are expensive and heavy. The batteries could be a lot smaller, and the hybrid Stirling can be smaller too. It has been shown that most trips are less than 45 miles round trip. A small battery could handle that much driving, and the Stirling can keep it charged up, as needed. The amount of power needed would be relatively small for constant speed, which is what is done most of the time. Consequently, the Stirling can keep up with the demand while not having to deliver all the power needed at one time. The electric motor can do that. Extra power for acceleration could come from ultracapacitors, which can also be charged by the Stirling motor.

Nuclear power can supply the energy to convert to hydrogen. Especially true if the cost of energy can come way down, as it is projected with the Focus Fusion device. In the meantime, nuclear power could be used from molten salt reactors. In such a case, no emissions would be produced at all. There would be some waste from the molten salt reactors, and no waste worth mentioning from the Focus Fusion device.



end update:

 

Comment:

This topic isn't new here on this blog, but what is new is this video. I hadn't seen it before. The thing that is different here is that it is a complete engine concept tested in real live situations over a period of time.

A Stirling engine was tested in a truck by NASA. Actually, more than one truck. One of the trucks was a service vehicle used on an airbase in Virginia. The other looked like a regular old pickup truck. The pickup appears to have driven everywhere you'd drive a conventional vehicle.

Popping the hood doesn't reveal anything radically different. It doesn't look like a conventional engine though. Incidentally, this test was done a long time ago. Back in the eighties, perhaps. The vehicle looks that way. It doesn't look modern.

The curious thing is why this technology hasn't been adopted. It is said to be "too heavy". The engine was only 75 hp, but what people don't realize is that most of the horsepower in a conventional engine is unnecessary. Internal combustion engines cannot start under a load. I'm thinking that public acceptance may be low for some reason, or that auto manufacturers may fear taking a chance on something different could be too risky of a decision.

There was a Ford program during the Energy Crisis of the seventies that tested Stirling engines in cars. The fault there was that it took too long to warm up. That could be an issue, but that issue could be overcome if they really wanted to do it.

Why bother with the Stirling engine at all? It is said to be clean and efficient. It can run on any heat source. For me, I'd like to be able to get one as a power generator. But these things are impossible to find. You can certainly find toys, but nothing serious like a generator. What gives?

If you were to scratch the surface of all the things that have appeared to have gone wrong, you might find a common denominator with this question. Just saying. It could well be the thing that I've been discussing since day one on this blog. Our culture may well have become dysfunctional. It is a "better mousetrap", but for some reason, it doesn't succeed. It makes no sense, but there's your common denominator. It's like mandating a vaccine to solve a problem that doesn't exist ( in children, covid is not an issue). If a "vaccine" that doesn't work can be thusly mandated, then it might be easy to understand why a motor that would be cleaner and more efficient cannot be adopted for some strange reason. The highest cost "solution" to solve a non-problem that has the least probability of success is the path taken. The very defintion of dysfunctional.

Update:

NASA report on the Stirling Engine Program

Comment:

After reading through the full report done back in the late eighties, I can see why the Stirling Engine has not replaced the internal combustion engine. For its size, it just doesn't put out the performance.

It could be adequate though. It all depends upon customer expectations. People are a bit used to better performance than these can offer, however. It would not be a marketing hit. It would probably be a dud.

Some folks would find the economy to be an attraction. Yet the internal combustion engine has some room to grow, apparently. The new Eco-boost engine in Fords packs quite a punch for its size. The fuel economy would be pretty good too, I imagine. That's why it was developed.

That doesn't dissuade me from being interested though. The value of this engine is that it doesn't need specialized fuel. It was tested with a lot of different fuels, so it can be used with most anything that can be burned. In fact, it doesn't require anything but a heat source. Therefore, the possibility of running a Stirling engine on concentrated solar power is a real possibility.