When we hear the word "steam," our minds automatically go back in time a hundred years or more. We are living under the belief that steam power is old-fashioned, outdated, crude and inefficient. Nothing could be further from the truth. Although some applications have moved away from steam power entirely, others are still using it today. Did you know that almost all of our electricity today is still made from steam power? From the coal-fired power stations that are the industry standard, to the latest, greatest designs in nuclear-power generating stations, they all work on the same principle of using large amounts of heat to make large amounts of steam, which then drives big generators to make electricity. As you're reading this on your sleek, modern computer, remember that most likely, the power for your computer is still being supplied by the same steam power that's been around for some 200 years.
The reason that's always been given for steam's demise is lack of efficiency. My favorite example of this kind of thinking is the automobile. In the earliest days of the automobile, the motoring public was confronted with three basic types of transportation. The first was the steam car, the oldest and best-understood form of technological power. Next was the electric car, which was a newer technology, but still very well understood for its day. Finally came the gasoline engine, and its cousin, the diesel engine, both internal-combustion designs.
Let us look at how the "big three" designs compare to each other. Again starting with steam, the earliest configurations had a boiler, essentially a big pot of water, that was located in a convenient location, and the steam was piped to the engine, which was located in another convenient location. Even though the basic design was improved over the years, it always suffered from the same problem of inefficiency, because not enough attention was paid to the thermodynamics of the system. A large amount of heat was applied to a large amount of water, which was wasteful. Then the steam was piped, usually a considerable distance, to the engine. Along every inch of that piping there were heat losses, adding-up over the length of the piping to the point where a great deal of heat had to be supplied to the boiler just to make sure that the steam arriving at the engine would be hot enough and under enough pressure. Because the engine was located at some distance from the boiler, the engine would take quite awhile to heat-up from the steam, and all the while the engine was absorbing heat, it was not making power from that heat.
Next let's take a look at the electric car. It was true a hundred years ago, and it's still true today, that the electric motor is the single most efficient way to move a car along the road. Period. End of argument. No matter what the specific design, every electric-powered car has essentially the same configuration. A motor with one moving part is connected right to the wheels of the car. Electric motors are clean, quiet, efficient, require no warm-up, and they are very powerful at accelerating a dead weight. Keep in mind as you read this, I'm not saying anything at all about batteries or any other means of storing electricity. The source of power for an electric motor is a different matter altogether. Right here, right now, I'm only concerned with the electric motor itself, and its ability to move a car. The early electric cars, and the latest ones being produced today, all suffer from the same basic problem, which is how to get enough electric power on-board to give the electric motor what it needs. The motor itself is not the problem, the power-storage issue is the problem, and always has been.
Now we come to the internal combustion engine. This design was the least-favored of the "big three" back in the early days of motoring. The electric car was clean, quiet, and instant-on, but was slow and had a short range. The steam car was clean, quiet, powerful, and fast, but required a sometimes-long warm-up time. The ICE design, even with its problematic features, could start instantly, did not require a long warm-up period, and was able to go long distances without refueling. Despite its crudeness at the time, it overcame the deficiencies of the other two major designs, and this put the ICE at the forefront of automobile engineering.
It can be argued that the modern ICE has been thoroughly refined over decades of use and millions of miles of motoring. I, however, would not make that argument. For example, the steam engine always had a clean exhaust, because it was an external-combustion design, and it did not suffer from the stinking, poisonous exhaust of the ICE. So, over many decades, the exhaust of the ICE has been cleaned-up, by using such things as exhaust-gas recirculation, positive crankcase ventilation, electronic fuel injection, catalytic converters, oxygen sensors, controlled ignition timing, oxygenated fuels, and more. My point should be obvious. The ICE design causes nasty, foul combustion products to be created in the exhaust, and then dozens of devices are added to the engine in order to counteract those noxious emissions, and this is called refinement by the manufacturers. Here is another point: ICEs by their nature run best at a single speed. Since that is incompatible with an automobile that must constantly speed-up and slow-down, a complex means of transmitting power from the engine to the wheels is required. In the simplest of cars, this was done with a two-speed transmission. In today's "refined" cars, the engine's power is sent to the road through an eight-speed transmission. Likewise, an ICE running at a single, fixed speed, as it would like to do, would require only the simplest of carburetors (such as we see on a lawnmower). Since a car engine must constantly change its speed, a complex carburetor, or even digitally-controlled fuel-injection system, is required to allow the engine to be flexible enough to be drivable. An electric motor, by comparison, requires none of those things. All that is needed is a motor controller and a motor.
You see, all the "refinements" we've made to the ICE over all the years that we've been using it, are supposed to make the ICE more like the steam car or the electric car were in the first place. Rather than fixing a couple of small problems with the steam or electric car in the beginning, we have elected instead to take the ugly duckling of the "big three" and dress it up in colorful clothing and declare that it's beautiful.
Part of the reason an ICE is efficient at all is because of the compression stroke that takes place before combustion and the power stroke. This has always been stated as the reason the ICE took precedence over the steam engine. Let me present this to you in another way. Every gallon of fuel contains "X" amount of chemical energy. Just to make things easier, I'm going to use some round numbers. Let's say a gallon of gasoline contains 100,000 Btu's of heat. If you simply burn that gallon of gasoline, you will get 100,000 Btu's of heat from it. Now let's burn that gasoline in an ICE. After the whole gallon of gasoline has been run through the engine, we will look at our measurements, and we will discover that 1/3 of the energy in the gasoline has gone straight out the exhaust pipe and been lost. Then we discover that another 1/3 of the energy in the gasoline has gone to heat the water in the radiator. That's 2/3 of the 100,000 Btu's we started with going to waste, accomplishing nothing. We are quite literally paying $3 for a gallon of gas, and throwing $2 a gallon away as wasted heat.
If, however, we take that same gallon of gasoline, and burn it completely, we will get all the heat back out of it. Then it just becomes a matter of engineering to get the heat from the burner to the driving wheels. This is where new, efficient designs in steam cars comes into play. Let me give you one idea for a better steam car design. Since it's all about heat, let's start with putting the heat where it's needed. Imagine, for example, if you took a blowtorch and used it to heat a cylinder head. The cylinder head would get very hot indeed, right? Now spray a small amount of water onto that heated cylinder head. It would instantly flash to steam, and almost all the heat energy in that steam would go toward driving a piston. Compare that to the old steam designs that located the boiler many feet from the engine, with all the heat-losses that occurred at every step of the way. You see, folks, it's all about making and using the heat, with as little loss as possible. The problem with steam cars was not the steam power itself, it was the thermodynamically-inefficient designs of the time. I have more ideas for steam cars but for now this example will do.
I want to see a return to steam power. Not in any nostalgic, turn-back-the-clock kind of way, not at all. I'm talking about modern, efficient steam power, using the latest advances in materials, and our best understanding of the laws of thermodynamics. I dream that someday, I will have the chance to build some of my designs and test them under real-world conditions. I would wager right now (if I had any money!) that my ideas will work, just based on a scientific understanding of how heat flows in a given system. By making heat efficiently, right where it's needed, many of the simplest problems of the old steam-car designs can be avoided. I'd like to see what a few decades of refinement would do to a new, improved type of steam car.
Anyone care to join me for a steam?
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