The purpose of utilizing a dynamometer would be to test the burden capacity for a train locomotive prior to putting it in service. It enables for that break-in of a new or newly rebuilt engine in the controllable environment. Engine manufacturers, rebuilders and several fleets have proven this sort of break-in procedure through years of experience. Properly run-in engines go longer, run better and cost less to maintain. This article highlights the operation of the water brake engine dynamometer.
An electric train engine without a load is only able to produce speed. Maintaining a given rate of revolutions each minute (RPM) takes a tiny amount of engine horsepower. The wann (More Signup bonuses
) dyno can be a means by that any controlled load could be added and monitored. Using a water brake dynamometer, the horsepower of the prime mover is converted into heat with the dynamometer water. The stators and rotors successfully accomplish that transfer of energy. Both the stators and rotors have pockets built within them. As water is brought into the engine dyno or chassis dyno by passages inside the stator, it's discharged to the dyno close to the center of rotation of the rotor assembly. This water entering the dyno will flow in to the pockets of the rotor. The lake is then accelerated from the rotation from the rotor assembly, which is coupled to the output shaft from the engine. As it increases (or accelerates), the lake will fly out as a result of centrifugal force. And as the water flies out, it ends up in pockets within the stator plates. The lake in these similar pockets inside the stator plates has a tendency to go out and is also once more met through the rotating rotor assembly. The lake is hasten (or accelerated) again, and also the constant acceleration and deceleration with the water, power is required that is converted into frictional heating of the water. The thermal conversion of engine chance to frictional heating of the water is supported by pure laws of physics.
Horsepower could be defined when it comes to heat. Heat loads are measured in terms of "BTUs" or British Thermal Units. A BTU of heat may be the amount of heat it would take to improve the temperature of 1 pound of pure water by one degree Fahrenheit. When dealing with water brake dynamometers, the heat loads in terms of BTUs are essential.
Because we are raising the temperature of just one pound water by one degree Fahrenheit, we are going to need to know a few more definitions. You can find 62.4 pounds of pure water in a cubic foot. There are 231 cubic inches in a gallon of pure water. Therefore, one gallon of pure water would weigh 8-⅓ pounds. One horsepower is equal to 2,545 BTUs hourly or about 45.5 BTUs for each minute. With this particular information, we could now determine the quantity of water which is required to absorb confirmed level of horsepower. The amount of water within the dyno at any given instant determines how much horsepower that it may absorb. The more water which is inside the dynamometer, the harder the dyno can absorb. You can not put more water in to the dyno than the amount for the degree of horsepower that you plan to test.
The dynamometer does not hold water. It is simply something for converting the horsepower into heat from the water. Because of this, you'll need a given flow with the dyno in a given horsepower rating. The amount of flow varies with the amount of horsepower being absorbed and is also directly proportional. The better the quantity of load required, the larger the quantity of water will need to be supplied.
The amount of water supplied for the dynamometer is controlled externally towards the dynamometer. This can be done either by a set of manual turn off valves mounted within the water supply line, from the electric remote load control valve or by the servo-operated inlet manifold option. Whether the manual or electric valves are used, they both accomplish exactly the same task. The broader
the valve is opened, the greater water it allows to circulate towards the dynamometer. This flow for the dyno is directly proportional to the amount of horsepower being absorbed.
An exhaust or outlet valve is also installed on the dynamometer. The purpose of this valve is always to conserve water while allowing the dynamometer to run on various temperatures of inlet water. Once we are converting horsepower into heat with the water, the connection with the inlet and outlet water temperatures becomes a crucial consideration. The exhaust valve
is a controlled orifice. The farther it really is opened, the higher the water consumption is going to be.
- 2014/02/06(木) 18:38:26|
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