ENGINE COOLANT CONDITIONING SYSTEM
|Type||: Non mixing closed loop cooling system|
|Temperature range||: 80°c~95 °c|
|Temperature Satbility||: ± 0.2 oC steady state , ± 2 oC dynamic|
|Indicating accuracy||: +-1.0°c|
The system essentially comprises:
Here, the raw water is used for controlled heat removal from the engine so as to maintain coolant outlet temperature say at 85o C. (settable range 80 oC ~ 95 oC)
Initial heating of coolant at 70 oC with auto timer so that engine is filled with hot coolant; insulated, hot water storage tank with level control, visual glass tube level indicator, over flow and drain, auto & manual filling provision.
Following Auto functions are provided:
ENGINE CRANKING SYSTEM
The Engine Cranking System consists of an AC Motor with Belt & Pulley Arrangement for giving drive to shaft of the starting mechanism. The starting mechanism uses pneumatic cylinders to push the shaft which is provided with a toothed ring for engagement with mating toothed ring on the dyno shaft. A Frequency Controller (V.F.D.) is used for cranking engine at a desired speed of cranking.
The engine cranking unit (positioned at non-driving end of dyno) and Dyno are mounted on a common base-frame. The frequency controller is used for cranking the engine at a desired speed of cranking and also for smooth engagement of cranking mechanism.
|Type||: Motorized with pneumatic cylinders|
|Motor||: AC Induction 3-phase(Make: CGL/Siemens)|
|Frequency Controller||: ABB/|
|Starting Speed||: settable thru’VFD|
|Drive thru’||: Belt and Pulley type arrangement|
|Safety interlocks||: proximity Switch for engagement and spped feedback for dis-engagement with free wheel clutch|
When ‘ENGINE CRANK’ command is given, AC motor starts running at a slow speed and at the same time pneumatic cylinders push forward the drive shaft of the starting mechanism forward. The toothed ring mounted on the drive shaft gets engaged with the mating toothed ring mounted on the non-driving end of the dyno rotor shaft and as soon as it gets engaged which is sensed by a proximity switch, motor starts running at cranking speed set on the VFD.
FUEL CONDITIONING SYSTEM
This system is suitable to control the fuel (diesel) temperature within the range of +40 oC to +45 oC (6 oC higher than cooling tower water temperature) throughout the test, at the engine inlet. For lower temperature range chiller is provided.
Fuel from the in-cell tank is passed through a heat exchanger, which is made of SS sheet metal. The water controlled at specific desired temperature is used to remove heat from fuel flowing through the heat exchanger.
It is observed that the temperature of fuel is maintained with ± 1 oC.
The system comprises:
Digital Temperature Indicating Controller For Heater
Bosch Fuel Pump
A sight flow indicator is provided in the fuel circuit for visual flow indication.
Following Auto functions are provided:
This unit is used for the remote control of throttle lever of an engine under test. The actuator is controlled such that the demand position set on the potentiometer is held constant. The System will have retention of the position even after power failure.
|Supply for Insturment||: 220 V ±10% AC, 50 Hz, Single phase|
|Supply for Drive||: 415 V ±10% AC, 50 Hz, three phase|
|Dimensions for Instrument||: 19” sub-rack of 2U size (88 mm)|
|Dimensions for Drive||: 380(w)x300(d)x600(h) mm|
|Control accuracy||: ± 0.2% of the set value|
|Adjusting path||: 10.0cm (maximum)|
|Response Time||: 400ms|
The system comprises:
A suitable mounting stand is provided for Servo Motor installation in the test-cell.
GRAVIMETRIC FUEL METER
The Gravimetric Fuel Consumption Time/Weight Indicator essentially comprises a unit which senses weight of fuel being consumed by the engine under test and an indicator-cum-controller to set either quantity of fuel in grams or time in seconds to display time required to consume set quantity of fuel or display quantity of fuel consumed in the set time.
The indicator comprises a keypad to set weight or time and LED display for the indication of fuel weight, fuel consumption time and fuel flow. The electronic circuit in the indicator ensures that the level of fuel in the glass container is maintained within the minimum and maximum level (internally set).
|Range||: 10 to 200 g or 50 to 500 g – any value can be set on instrument / PC|
|Indicating Accuracy||: ± 0.2% of fsd for weight , ± 0.1 s for time|
|Resolution||: 0.1 g for weight , 0.1 s for time|
|Setting of Time/Weight||: Special function keys on the keypad|
|Disply(for Weight/time)||: LED|
|Time base||: Crystal Oscillator|
|Alarms||: For high and low fuel levels with trip at high level.|
|PC interfacing||: Thru’ RS 485 (for actual weight consumed & fuel consumption time)|
EDDY CURRENT DYNAMOMETER
The dynamometer comprises:
The construction comprises a casing (Stator assembly) that houses the field coil and cooling chambers. A thin spoked steel rotor revolves in the casing. The stator assembly is mounted on a sturdy MS fabricated & machined base-frame supported by trunnion bearings.
When the excitation current is passed thru the coil, a magnetic-flux field is formed. An equal and opposite magnetic field is induced in the heat exchanger walls facing the rotor and this field is of a pulsating form corresponding to the frequency of the passing rotor spokes. This changing field produces eddy currents in the heat exchanger walls, which oppose the excitation field, thus causing retarding action to be imposed on the rotor. The magnetic flux lines developed in the rotor are parallel to the axis and therefore the thickness of the rotor is minimized, resulting in a low moment of inertia.
The function of water passed through cooling chambers is heat dissipation only and it does not come in contact with the rotor assembly. Hence, control of load depends entirely on the level of excitation and therefore fluctuations in pressure and flow of water have no effect whatsoever on the stability of load absorption as water is used for cooling purposes only.
The dynamometer is BI-DIRECTIONAL, DRY GAP TYPE. In a dry-gap unit, the only resistance to movement of the rotor is that of bearing friction and the small effect of windage. With zero excitation, an almost no-load condition can be achieved over the entire speed range.
The Dynamometer is provided with following safety features: