 | University of Virginia record February, 1910 |  |
ENGINE AND BOILER TESTS.
The Steam Engine Tests are made on the high-speed Ball engine,
which operates the shops. This motor has been specially equipped
Sweet separator; humidity determinations are thus made twice—
once by a separating calorimeter before the steam enters the separator,
and again by a throttling calorimeter as it enters the cylinder.
It is fitted with proper indicators, and permanent indicator rigging
so that at any time cards may be taken and the indicated horsepower
determined. In like manner a rope friction brake is so arranged
that it may be at once applied for the determination of brake
horse-power. Connections are so made with a Wheeler surface condenser
that the engine may at will be operated either condensing or
non-condensing. Provisions are made for measuring the temperatures
and the amounts of the condensation water and the condensed
steam produced during the run. With these data a complete heat
balance of the experimental run is attainable.
For Steam Boiler Tests the boilers of the University heating and
lighting plant are available. The department is equipped with the
necessary apparatus—thermometers, gauges, steam calorimeters, fuel
calorimeters, gas analyzers, scales, tanks, and so on. Students of
Mechanical Engineering are taught by practical lessons in the boiler
room the standard methods for boiler trials, and the class makes each
session at least one complete trial.
The Gas Engine Tests are made on an Otto machine of 15 I. H.
P. and 12 B. H. P. This is also provided with its friction brake, indicator
rigging, and indicator. The cooling water is run in from calibrated
tanks and provision is made for observing not only its amount
but the initial and final temperatures. Gasoline or alcohol is used
as fuel, and is run in from a graduated wrought-iron bottle, so that
the amount consumed is determined. The heating power is obtained
by an independent test with a Rosenhain calorimeter. Samples of the
burnt gases are drawn from the exhaust pipe and analyzed in an
Orsat gas apparatus. With these data, and the observed numbers
of revolutions and explosions, the heat balance is worked out.
The Refrigerating Tests are made on a Remington Ice Machine
of one ton capacity. This is an ammonia compression machine driven
by an electric motor. Instead of brine, plain water is used, heated
by a steam jet to 100 degrees and then cooled down to 40 degrees by
the machine. A run is first made with the pipes empty in order to determine
the friction horse power. The ammonia is then turned on
and the run is made under load. In both cases the power consumed
is measured both by watt-meter and by am-meter and volt-meter
readings. The tanks are accurately calibrated and careful measurements
of the temperature are made through the run. Indicator cards
are also taken from the ammonia cylinders and the number of revolutions
is registered by counter. With these data the mechanical and
thermodynamic performance of the machine are figured out.
| University of Virginia record February, 1910 | |