A good bit of this material is taken from American Heritage Invention and Technology article from 1998. Other information taken from my notes.
In 1968, a renaissance in steam-car technology suddenly began, amid new found concern about the pollution caused by internal-combustion engines.
The U.S. government had recently imposed strict emissions limits on automobiles, and in May 1968 several federal agencies held hearings on alternative power plants. Among the first to speak out in favor of steam were Calvin E. and Charles J. Williams, twins from Ambler, Pennsylvania, who for years had been using profits from their family’s construction business to experiment with steam. They drove their steam-powered convertible, on which they dubiously claimed to have spent $2 million, to Washington and invited Sen. Edwin Muskie, Sen. Warren Magnuson, and others to go for spins. Bureaucrats were impressed by the vehicle’s silence, acceleration, and supposed 30-mpg fuel efficiency (on kerosene). The Williams brothers maintained in committee hearings that steamers burn fuel more slowly and steadily, and thus more completely, than internal combustion engines. Steam power, they said, is also more mechanically efficient.
That same year, Don E. Johnson, the 36-year-old president of Steam Dynamics, in Mesa, Arizona, argued that his 150-pound, 150-horsepower steam engine was much lighter than an equally powerful conventional one. He could make this assertion by ignoring all the ancillary parts of the engine, such as the boiler, burner, and tanks. Johnson had originally developed his engine for helicopters but believed it would work just as well in automobiles.
Ford and General Motors had already gotten into the act, albeit in lukewarm fashion. In March 1968 Ford had announced a joint steam development program with the Thermo Electron Corporation, of Waltham, Massachusetts. GM, meanwhile, worked with another start-up steam company, Energy Systems, Inc., and offered to supply several steam-powered sedans to the California Highway Patrol for in-service testing.
The man who made the most noise about steam, though, was the brash and overconfident William P. Lear of Learjet fame. At a decommissioned military base outside Reno, Nevada, Lear developed several types of steam and steamlike engines. One was what he called an “involute expander,” which used intermeshing helical screws. Another was a 12 cylinder opposed-piston engine based on the British Napier Deltic diesel; the cylinders formed side-by-side triangles. A third was the Lear Vapor Turbine System, which involved a sealed turbine that used not steam but a revolutionary new fluid called Learium. Unfortunately, Learium was never developed.
Thermo Electron Corp of Waltham, Mass. designed an engine that would use instead of water a non-aqueous organic fluid to drive it. The fluid did not corrode the metal, worked at much lower temperatures and pressures, and therefore should have cut cost of the engine considerably.
In addition to Ford's $4 million, Thermo-Electron put as much as $2 million in the project, and kept the rights to any technology developed. Ford would have to pay royalties to sue the engine, but in 1970 held 10,000 shares of Thermo Electron, and thus had options on stock that eventually could give it at least a 25% holding.
The organic vapor in Thermo Electron's design drove a piston engine. It is condensed and returned to the boiler in a hermetically sealed closed cycle. As in other steam engines, the fuel heating the boiler is burned continuously with lots of air. This virtually eliminated pollution by unburned hydrocarbons. The low burning temperature also cut down on nitrogen oxides.
Cost, weight, size and slow startup proved problematic problems. The organic vapor posed problems. Thermo Electron used thiophene. William Moore, director of industrial design for Lear Motor Corp., which has put its own steam car on a back burner, said Lear rejected thiophene because of its high volatility and toxicity.
The man who made the most noise about steam, though, was the brash and overconfident William P. Lear of Learjet fame. At a decommissioned military base outside Reno, Nevada, Lear developed several types of steam and steamlike engines. One was what he called an “involute expander,” which used intermeshing helical screws. Another was a 12 cylinder opposed-piston engine based on the British Napier Deltic diesel; the cylinders formed side-by-side triangles. A third was the Lear Vapor Turbine System, which involved a sealed turbine that used not steam but a revolutionary new fluid called Learium. Unfortunately, Learium was never developed.
In the end Lear did build a steam-powered Chevrolet Monte Carlo and a steam-turbine bus. With his usual hyperbole, he announced plans for a steam-powered Indianapolis race car, and he even scraped out an oval track behind his warehouse, supposedly to test it. But because he had so many different projects going—plus horrific problems with his engineering staff—nothing ever came of any of his steam-powered visions.
In October 1973 the Arab oil embargo hit, forcing automakers to turn their attention away from steam to the more immediate challenges of downsizing and making the internal-combustion engine cleaner and more fuel-efficient. They succeeded well enough to put steam out of contention. Despite the progress some engineers believed they were making between 1968 and 1973, steam cars continue to pose seemingly insuperable challenges, principal among them being fuel economy. There’s no promise of future improvement, as there is with electric cars, in which batteries are being made smaller and smaller.
In October 1973 the Arab oil embargo hit, forcing automakers to turn their attention away from steam to the more immediate challenges of downsizing and making the internal-combustion engine cleaner and more fuel-efficient. They succeeded well enough to put steam out of contention. Despite the progress some engineers believed they were making between 1968 and 1973, steam cars continue to pose seemingly insuperable challenges, principal among them being fuel economy. There’s no promise of future improvement, as there is with electric cars, in which batteries are being made smaller and smaller.
Tidak ada komentar:
Posting Komentar