Delphi Multec 3.5, Руководство по применению

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Product Description Multec 3.5 Fuel Injector Application Manual
3-16 Delphi Energy and Chassis Systems
Revision: 11/05-1
6. Vehicle Calibration Dependent Issues
•
When sizing injector flow rate for any engine/vehicle application,
the engineer should also consult the fuel calibration engineer for
calibration specific fuel concerns. An example list is:
−
Piston Protection
−
Power Enrichment
−
Converter Over-temperature Protection
−
Cold Start Requirements
−
Any application injector duty cycle limitations
Some calibrators desire that the injector should be sized to meet an A/F
ratio range of 9.0 to 10.0 A/F [equivalence ratio (
φ
) = 1.63 to 1.47] at the
maximum horsepower point. However, the resulting required linear flow
range might warrant a flow compromise.
Once the preceding specifications are determined, proceed with the
following calculation to obtain maximum fuel flow per injector.
Example:
Engine Rated Horsepower (HP) @ 4500 RPM
300 HP
BSFC (Lb
m
/HP*Hour) @ 4500 RPM
0.53 Lb
m
/HP*Hour
Number of Cylinders 8
Minimum fuel flow per injector
(Make up pulses) @ 600 RPM
0.023 gm/sec
Calibration Specific Issues (Values are guidelines)
Power Enrichment
11.5 A/F Ratio = 1.25 Equivalence Ratio (
φ
)
Converter Over temperature 11.0 A/F Ratio = 1.33 Equivalence Ratio (
φ
)
Cold Start Requirement
10.5 A/F Ratio = 1.40 Equivalence Ratio (
φ
)
Fuel Pump Compensation Compensation for lower pump pressure at
high flow
1. Multiply the maximum engine horsepower by the brake specific fuel
consumption to obtain required fuel flow per hour.
(300 Hp) * (0.53 Lb
m
/HP*Hour) = 159 Lb
m
/Hour
2. Convert to grams/second.
(159 Lb
m
/Hr) * (454 grams/ Lb
m
) * 1 hr/3600 sec) = 20.0 gm/sec