Information about compressed air filter
All compressors supplied by Volvo
Penta must be equipped with air filtration before the air inlet. Air filters
are included in the compressor kit and can also be ordered separately. The
compressor air filter must be changed at the same time as the engine air
filter. The compressor inlet must be connected to the combustion air duct
between the engine air filter and the turbocharger (if possible vertically from
above). The connection point must always be positioned before the crank case
ventilation connection to avoid the compressor drawing in oil. On the other
hand, the distance to the turbocharger must be sufficient to prevent the pulsating
compressor from affecting the turbocharger. The air inlet hose must have an
inner diameter of at least 22 mm (0.87") and be suitable for hydraulic
oil. When engine coolant is drained, the compressor cooling system must also be
drained if there is a risk of freezing.
General
Volvo Penta supplies different
types of hydraulic pumps. These pumps are only intended for power steering
systems and are not designed for continuous use. However, Volvo Penta is able
to supply a number of different flanges for engine-mounted hydraulic pumps for
continuous operations. Refer to the Volvo Penta Sales Support Tool, Partner
Network.
IMPORTANT!
Because hydraulic pumps involve
large cyclical torque variations to the camshaft gear it is essential that
pumps not supplied by Volvo Penta be approved by Volvo Penta before
installation on the engine concerned.
Hydraulic Steering Pumps
delivered by Volvo Penta
The pump gear is installed on a
cylindrical shaft with a key. Before the gear is installed on the shaft it must
be heated to maximum 200 °C (392 °F).
D9 and D16
engines
For TAD94X and TAD164X engines it
is possible to order a hydraulic steering pump on which the fuel pump is end
mounted on the power steering pump. There is a safety valve in the hydraulic
pump, but the supplier nevertheless recommends that a flow and pressure valve
be installed in the circuit. If there is no requirement for a hydraulic steering
servo pump, a dummy is installed instead of the pump (in the same housing as
the fuel pump. Refer to the Volvo Penta Sales Support Tool, Partner Network for
technical details.
System
Configuration
In order for the hydraulic pump
to function satisfactorily it must be installed correctly. The following
factors influence function:
• Tank
• Suction
line
• Inlet line
• Drain line
• Oil filter
• Air filter
• Hydraulic
oil
Tank
In order for the hydraulic tank
to function correctly a number of simple calculations need to be made. For
satisfactory hydraulic function, consideration must be given when designing the
tank to system venting, oil heat absorption and expansion. The collection of
water and dirt is another important function. The illustration shows an optimal
tank. Maximum hydraulic oil volume in the hydraulic tank must be 10 - 20 % lower
than tank volume. Hydraulic oil volume ≥ Pump flow.
Heat
absorption
Transmission losses occur in all
hydraulic systems, as do hydraulic pump and engine losses. All of these are
transformed into heat in the oil, which means a choice between cooling the oil
or allowing it to absorb heat. If operational time exceeds one hour the oil will
usually require cooling.
The required tank volume can be
calculated according to the following:
NOTICE! Cooling capacity is not
doubled if tank volume is doubled. Conversely, heat absorption capacity is
doubled. Cooling capacity only increases by 50 %. Remember to adjust the size
of lines, tank and filters to the systems maximum circulation flow.
Suction lin
Oil flow to pump suction must be
free and without restrictions. This requires a suction line of sufficient
diameter and the shortest possible length without flow limitations. Recommended
flow speed: 0.5 - 1 m/s (1.6 - 3.3 ft./s).
Inlet line
Too narrow an inlet line causes
unnecessary pressure losses that are transformed into heat. At a flow of 100
l/min a pressure drop of 10 bar (145 PSI) will create around 1.7 kW of heat. A
flow speed of 4 to 7 m/s (13.1 - 23.0 ft./s) is recommended at a pressure of
100-300 bar (1,450 - 4,350 PSI).
Drain line
Pumps that are not self draining
must have a drain line installed directly on the tank. The flow to the drain
will increase with pump load. Overpressure will occur in the pump when the oil
in the drain line accelerates and flow increases. This pressure must not exceed
2 bar (29 PSI) in normal conditions. A drain line the same size as the pump
connection is recommended.
Oil and air
filter
Nominal filter flow speed must
correspond to the maximum flow that can occur in the system. For example, a
system with a double-acting ram, such as a crane, can give double the pump flow
in return. The following filtering speeds are recommended for maximum pump
lifetime:
Clean environment or low
pressure 25 μm
Dirty environment or high
pressure 10 μm
Hydraulic
oil
A suitable hydraulic oil grade
must be used. At operational temperature oil viscosity must be 20 to 30 cSt.
General
Recommendations
A high power take-off ratio
(greater than 1:1) means that a smaller pump can be used. This is usually the
best alternative both technically and economically. An exception is when a
diesel engine must be run at high rpm, as a lower power take-off ratio is necessary
to avoid overspeeding the pump.
Check
- Compare the power take-off max
permissible load with the pump max permissible load.
Note that the formulae do not
take frictional losses (mechanical efficiency) into account. However, the
discrepancy is not greater than around 2 %.
- Use the engine power graphs and
hydraulic pump data to make sure the engine is able to drive the pump.
The following formula can be used
to calculate hydraulic pump power requirement:
Note that efficiency (η) varies
depending on pump type and size and operational conditions.
Typical efficiency is 85 to 95 %
It is important to note that a hydraulic pump with 90 % efficiency emits twice
the heat as a pump with 95 % efficiency.
Note: We are diesel generator manufacturer/factory in China and can provide 25KVA to 3125KVA diesel power generator with various types, contact us at: sales@dieselgeneratortech.com.
Comments
Post a Comment