CUMMINS ENGINE 4JB 103series

kimswed 2007.04.26 19:11 조회 수 : 1507 추천:130

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Putian ChinaHanji Power Limited,Co main tech data for diesel engine#4JB1
Model Ser. 4JB1 Nature
inspiration engine
4JB1 supercharged
engine
4JB1 supercharged
/O2 engine
4JB1 Turbo-charged
Center cold Altogether
axle engine
Inlet Method Nature inspiration supercharged supercharged/OII Turbo-charged Center cold Altogether axle
Diesel Engine Model oil-cooled,four-stroke, in-line,valve in-head oil-cooled,four-stroke, in-line,valve in-head oil-cooled,four-stroke, in-line,valve in-head oil-cooled,four-stroke,in-line,supercharged,center Leng,common-railed
Number of Cylinders 4 4 4 4
Bore and Stroke 93×102 93×102 93×102 93×102
shape size(L*W*H)mm 734×612×682 742×634×718 742×634×718 742×634×718
New Weight(kg) 224 230 230 250
Exhaust Volume (cc) 2.771 2.771 2.771 2.771
compression ratio 18.2 18.2 18.2 17.2
fuel supply mode direct injection direct injection direct injection direct injection
Lubrication Method The forced circulation splashes duplicate is suitable The forced circulation splashes duplicate is suitable The forced circulation splashes duplicate is suitable The forced circulation splashes duplicate is suitable
Cooling Method sealed pressed circulation sealed pressed circulation sealed pressed circulation sealed pressed circulation
Starting Method electric electric electric electric
EG stop mode fuel control systme fuel control systme fuel control systme fuel control systme
output power/speed(kW/r/min) 57/3600 68/3600 68/3600 85/3600
Maximum Torque(N·m/r/min) 172/2000 210/2100 210/2100 285/2100
idle speed(r/min) 750±50 750±50 750±50 750±50
maximum no load governed speed(r/min) 4200 4200 4200 4200
Min fuel comsumption on Full load(g/kW·h) 224 230 230 250
Temperature of cold start -25 ℃ -25 ℃ -25 ℃ -25 ℃
Temperature of exhaust <600 ℃ <600 ℃ <600 ℃ <600 ℃
noise Db(A) ≤ 106 ≤ 106 ≤ 106 ≤ 100

 

Short circuit interrupting ratings of the Low Voltage Generator
Circuit Breakers.
Low voltage circuit breakers are rated on symmetrical basis. Therefore the interrupting
ratings (or interrupting capacity) of the low voltage circuit breakers, published by
manufacturers, are expressed in RMS symmetrical current.
The instantaneous function of the circuit breaker trip unit is designed to react to the
peak value of the phase current. Since circuit breakers are capable of parting their
main contacts during first 1-3 cycles of the fault, their short circuit ratings should be
higher than the maximum available symmetrical fault current during the 1st cycle of a
fault.
Generator direct axis subtransient reactance (X"d) is the reactance of the stator winding
at the instance of fault. RMS symmetrical values of the fault current at the generator
terminals can be calculated as follows:
Three phase fault:
X d
Isc E
3 "
=
Line to Neutral fault:
2 0 "
3
X d X X
Isc E
+ +
=
Where:
E – generator line to line voltage before fault, Volts
X”d -- generator direct axis subtransient reactance, Ohms
X2 -- generator negative sequence reactance, Ohms
X0 -- generator zero sequence reactance, Ohms
Note: all reactance values should be used as the “worst case values”. Example: if X”d
value is specified by the generator as 20% +/- 15%, that the “worst case value” of X”d
should be calculated as 20%* 0.85 = 17%.
Typical values for a 2.25 MW, 480 V generator are: X”d= 0.013 Ohms (15.9%), X2=
0.012 Ohms (14.6%), X0= 0.003 Ohms (3.7%).
As can be seen if the generator neutral is solidly grounded, the ground fault current will
exceed the value of the three phase fault current.
Let’s assume that two (2) of the above generators are operated in parallel with high
impedance grounded neutral. In this case, three phase bolted fault will produce the
highest fault current, since line to ground fault will be limited by the neutral grounding
resistor(s). Than the highest fault current they can produce is approximately 42,615
Amperes of RMS symmetrical current. For the “worst case scenario” we will assume
Copyright © 2006 Advanced Power Technologies, Inc.
www.aptinc.net
2
close proximity of the switchgear to the generator sets and therefore ignore the values
of X and R of the connecting cables as negligible. In this case, as a rule of thumb, if the
80% of nameplate interrupting capacity of the feeder circuit breakers connected to this
generator bus is above 42.615 kA, no further calculations are generally required.
If the 80% of nameplate interrupting capacity of the feeder circuit breakers connected to
this generator bus is not above 42.615 kA, than further evaluation is required as
outlined below.
1. Type of low voltage circuit breaker. Most low voltage circuit breaker used in
North American power systems are rated to ether ANSI C37 standards or UL
489. ANSI rated circuit breakers are tested at 15% Power Factor (P.F.) UL 489
rated breakers are tested at 20% Power Factor.
2. Calculate short circuit Power Factor or Power System X/R ratio. System Power
Factor and X/R ratio are both indicators of the mathematical relationship between
system reactance and resistance. They are related by the following
formula: P.F . = cos(tan −1 ( X / R )) . For example 15% Power Factor
corresponds to 6.59 X/R ratio and 20% Power Factor corresponds to 4.9 X/R
ratio. If actual system fault X/R ratio higher than the X/R ratio the circuit breaker
was tested to, than the fault interrupting rating of the circuit breaker needs to be
adjusted by applying a derating multiplier further called “Derating Factor”. To
determine required interrupting rating of the circuit breaker, value of the available
fault current needs to be multiplied by a “Isc Multiplying Factor” as outlined in
Table 1.
The reason the system X/R ratio needs to be considered is that the actual generator
fault current is not symmetrical. It consists from the symmetrical AC component and a
DC component sometimes called DC offset. A typical asymmetrical current wave is
shown in Figure 1. The actual degree of asymmetry and therefore the actual magnitude
of current the circuit breaker will need to interrupt, depends on the system X/R ratio and
when in the power cycle the fault occurs. The higher the system X/R ratio, the greater
the potential for the instantaneous peak value of the fault current to reach its maximum
theoretical instantaneous peak value. The initially asymmetrical fault current becomes
symmetrical as the DC component of the fault current decays.
Copyright © 2006 Advanced Power Technologies, Inc.
www.aptinc.net
3
Figure 1
For a typical 2.25 MW, 480 V generator system described above the “worst case” X/R =
0.013/0.0015, which corresponds to an X/R ratio of 8.67 or system Power Factor of
approximately 11%.
The Table 1 below can be used to determine the required derating of the circuit
breakers interrupting ratings. In our example the required feeder circuit breaker
interrupting ratings will be:
1. For an ANSI rated circuit breakers: 42.615 kA * 1.049 = 44.7 kA
2. For a UL 489 rated circuit breakers: 42.615 kA *1.11 = 47.3 kA