3-7022 heading face
supply
electric current
set up
count
report
tell
Compile:
Audit:
Ratification:
Electrical system
20 1 1 August
Chapter 1 Power Supply Design Report
I. Description of power supply
The gateway length of 3-7022 heading face is 1688m, and the total installation load is 698.4kw The power supply scheme adopts GB-80# high-explosive switch (1#, 2#) to supply power from 2# distribution point II in No.7 mining area to 3-7022 distribution point. Because the roadway design is long, the voltage loss at 800 meters can't meet the power supply needs, so two sets of power supply schemes are adopted. Among them, 3-7022 distribution point 1# high-explosive switch supplies power to KBSGZY-660V/6 shift transformer (1#) in the early stage, which is responsible for supplying power to a belt conveyor and various mechanical and electrical equipment in the working face 800 meters before the gateway (see the early stage power supply system diagram for details). In the later stage, the KBSZY-630/6 transformer (2#) was supplied with power by the 2# high-explosive switch in the 3-7022 distribution point. After the voltage was reduced to 660V, it was responsible for supplying power to the roadheader, drainage pump and electromechanical equipment in the 900-meter working face behind the gateway, while in the early stage, it was supplied with power by the KBSZY-630/6 (1 #) transformer.
The double-circuit power supply of the fan comes from the dedicated transformer of I-circuit KBSGZY-T-200/6/0.66 and the dedicated transformer of II-circuit KBSGZY-T-200/6/0.66 at No.2 distribution point in No.7 mining area.
Second, the electrical equipment load statistics
Table 1:
Serial number equipment name model number motor power capacity voltage remarks
1 TBM EBZ- 132 1 2 15kW 2 15kW 660v
Two ssj-80/2× 55 2× 55kw 220kw 660v belt conveyors.
3 tension winches jj-JJ-4 2 sets 4KW 8KW 660V.
4 endless rope winch sq-801110kw110kw660v.
5 scheduling winch JD-11.41.1.4kw1.4kw660v.
6 dispatching winch JD-25 1 25kw 25kw 660v
7 centrifugal pump zs50-2×100f155kw55kw660v
8 sewage pump bqw 15-30/32 3kw 6kw 660v
9 exploration diamonds zlj-2501.4kw 4kw 660v.
10 local ventilator FBDNO 6.3/2× 2222 * 22kW 44kW 660V special power supply.
1 1 total14 698.4kw.
Chapter II Selection of High Voltage Cables
Selection of high-voltage cables from 2# distribution point to 3-7022 distribution point in air inlet lane of No.1 and No.7 mining areas
1, cable type determination
According to the principle of determining the cable type, the resistance cable for coal mine is selected, and the high-voltage cable for supplying power to the mobile substation is MYPTJ-3.6/6 movable metal shielding and monitoring soft cable for coal mine.
2. Determination of cable length
1. According to the mining engineering planning, the total length of 2# distribution point in No.7 mining area is about 300 meters away from the distribution point in 3-7022 air inlet inclined lane.
Actual cable length l1= kl2 =1.1× 300 = 330m.
Where L 1 is the actual cable length;
L2 is the length of the cable laying path;
K is the growth factor, and rubber cable is 1. 1.
3, cable section selection calculation
Preliminary selection of cable section according to continuous allowable current
= 0.7×698.4 = 489 kW
=489/0.8=6 1 1KVA
……(2- 1);
..... demand coefficient of line load; Take 0.6 ~ 0.75
..... Apparent power of total line load, kVA；;
..... the rated voltage of the line, kV.
Will be substituted into the formula (2- 1):
= 0.7×6 1 1/×6 = 4 1(A)
According to the cable ammeter, the long-term allowable current carrying capacity of the flexible cable with rubber sheath for movable metal shielding monitoring in coal mine with the model of MYPTJ-3×50+3×25/3+3×2.5 is 173A, and the cross section of the main core wire is 50mm2, which meets the selection requirements.
Second, the choice of cable from 2# high explosive to 2# displacement transformer
1, cable type determination
According to the principle of determining the cable type, the resistance cable for coal mine is selected, and the high-voltage cable for supplying power to the mobile substation is MYPTJ-3.6/6 movable metal shielding and monitoring soft cable for coal mine.
2. Determination of cable length
1. According to the excavation project plan, the total displacement length of 2# with high blasting distance is about1000 m..
The actual cable length is l1= kl2 =1.1×1000 =1000 m.
Where L 1 is the actual cable length;
L2 is the length of the cable laying path;
K is the growth factor, and rubber cable is 1. 1.
3, cable section selection calculation
Preliminary selection of cable section according to continuous allowable current
= 0.7× 280 =196kw
=196/0.8 = 245kVA
……(2- 1);
..... demand coefficient of line load; Take 0.6 ~ 0.75
..... Apparent power of total line load, kVA；;
..... the rated voltage of the line, kV.
Will be substituted into the formula (2- 1):
=0.7×245/ ×6= 17A
According to the cable ammeter, the long-term allowable current carrying capacity of the flexible cable with rubber sheath for movable metal shielding monitoring in coal mine with the model of MYPTJ-3×50+3×25/3+3×2.5 is 173A, and the cross section of the main core wire is 50mm2, which meets the selection requirements.
Chapter III Selection and Calibration of Low Voltage Cables
I. Determination of cable model
According to the requirements of "Coal Mine Safety Regulations", it is necessary to choose the flame-retardant cable that has obtained the safety mark of coal mine products, so the MY type flexible cable with movable rubber sleeve for mine, which is often used underground, is selected.
Second, the cable section selection calculation
Current carrying capacity of rubber sheathed flexible cable for mine;
Table 2
Main core section (mm2) Allowable current carrying capacity of long-term continuous load (A)
4 36
6 46
16 85
25 1 13
35 138
50 173
70 2 15
95 260
Select the cable section according to the long-term allowable current.
The maximum long-term working current of a conductor supplying power to a single motor or two motors may be the rated current of the motor. The trunk line supplying power to three or more motors (including three) can be calculated according to the following formula:
………(3- 1)
Where: ... sum of rated power of electrical equipment carried by the line, kW;
..... demand coefficient of line load; Take 0.5
..... the weighted average power factor of the line load; Take 0.8
..... Rated voltage of the line, V ..
Check the cable section according to the allowable voltage loss.
Table 3 Maximum voltage loss of underground low-voltage power grid under different rated voltages
rated voltage
Secondary voltage of UN/UN transformer
The minimum allowable voltage of u2n/V electrical equipment is 0.95UN/V, and the maximum allowable voltage loss of the line ur = u2n-0.95 un/v.
127 133 120 13
660 690 627 63
The voltage loss on the line resistance can be calculated as follows:
………(3-2)
Where: △ ur ... voltage loss on conductor resistance, v;
The abbreviation of UNITED NATIONS ... the rated voltage of the line, V;
..... the sum of the rated power of the electrical equipment carried by the line, kW;
Los Angeles, ... Length of line conductor, m; Cross-sectional area, mm2；;
Rsc…… ............................................................................................................................................................................... Was) Difference Table: 42.5
..... demand coefficient of line load;
The current carrying capacity of 1 and 1# cables transferred to the distribution point of the belt conveyor head is as follows:
Substitute = 0.5, = 660, = 260.4 and cos φ = 0.8 into the formula (3- 1):
ICA = 0.5×260× 1000/( 1.73×660×0.8)= 142 A
Look-up table 2 shows that the long-term allowable current of 50mm2 flexible cable with movable rubber sleeve for mine is IP =173 a > Ica= 142 A, so MY-3×50+ 1× 16 flexible cable with movable rubber sheath is selected.
Substitute =0.5, =660, =260, L=50, A=50 and rsc=42.5 into Formula (3-2):
△Ur= 0.5×260×50× 10？ /660×42.5×50 = 4.6 & lt； Article 63(V)
Choose to meet the requirements
2. The cable carrying capacity from 1# to the second distribution point of belt conveyor head is:
Substitute = 0.5, = 660, = 1 14 and Cosφ= 0.8 into the formula (3- 1):
ICA = 0.5× 1 14× 1000/( 1.73×660×0.8)= 62 A
Look-up table 2 shows that the long-term allowable current of 50mm2 flexible cable with movable rubber sleeve for mine is IP =173 a > Ica=62 A, so MY-3×50+ 1× 16 flexible cable with movable rubber sleeve for mining is selected.
Substitute =0.5, = 660, = 1 14, L = 900, A = 50, RSC = 42.5 into formula (3-2):
△Ur = 0.5× 1 14×900× 10？ /660×42.5×50 = 37 & lt； Article 63(V)
Choose to meet the requirements
3, 2# class to the working face distribution point cable current-carrying as follows:
Substitute = 0.5, = 660, = 280 and Cosφ= 0.8 into the formula (3- 1):
ICA = 0.5×280× 1000/( 1.73×660×0.8)= 153 A
Look-up table 2 shows that the long-term allowable current of 50mm2 flexible cable with movable rubber sleeve for mine is IP =173 a > Ica= 153 A, so MY-3×50+ 1× 16 flexible cable with movable rubber sheath is selected.
Substitute =0.5, =660, =280, L=20, A=50 and rsc=42.5 into Formula (3-2):
△Ur= 0.5×280×20× 10？ /660×42.5×50 = 2.0 & lt； Article 63(V)
Meet the requirements.
Chapter IV Selection of Low Voltage Switch
First, the selection principle
According to the "Coal Mine Safety Regulations", the use scope of all kinds of mine low-voltage switches should be determined according to the methane level, coal (rock) explosion risk and ventilation conditions of their use places.
1, mine flameproof switch is used in any place where there is methane outburst mine and the mining area air intake roadway, return air roadway and mining face where there is methane and coal dust explosion danger mine. The application scope of mine intrinsically safe switch and mine flameproof and intrinsically safe switch is the same as mine flameproof switch.
2, choose mine low-voltage switch, its rated voltage must be greater than or equal to the rated voltage of the controlled line; Its rated current is greater than or equal to more than 2 times of the long-term maximum actual working current of the controlled line load. At the same time, the setting current value of overcurrent protection relay should be selected according to the needs of control circuit.
3. The number and inner diameter of the connection bell mouth of the mine low-voltage flameproof switch should meet the requirements of the number and outer diameter of cables selected by the controlled line. Only one cable can be connected to a loudspeaker.
Second, the determination of low voltage switch model
1, according to the selection principle of mine flameproof switch, mine substation and distribution point of working face are used as low-voltage distribution lines.
2. Main technical data sheets
Table 4:
Model rated voltage (V) rated current (A) setting multiple
kbz 16-400 660 400.00 3- 10Ie 3
Third, the setting and calibration of low-voltage switch protection device
1, setting current calculation of low voltage switch
Overload setting of feed switch;
…………(4- 1);
Short circuit setting of feed switch;
………(4-2)
The setting value of short circuit protection is 6 ~ 8 times that of overload protection;
..... the rated (or actual) starting current of 1 motor (or multiple motors starting at the same time) with the largest starting current in trunk load;
..... sum of rated currents of other electrical equipment except 1 motor with the largest starting current (or multiple motors are started at the same time) in trunk load;
Sensitivity check of protection device
……(4-3);
..... Minimum two-phase short-circuit current at the end of protection range;
Setting calculation of overload protection for 1# feed switch;
Will be substituted into the formula (4-1):1.1×142 =156.2a.
Setting value of overload protection = 160A.
Setting calculation of short-circuit protection for 1# feed switch;
The setting value of short circuit protection is 6 ~ 8 times that of overload protection;
Setting value of short circuit protection = 160×8= 1280A.
Sensitivity verification of 1# feed switch protection device;
Look-up table shows that the minimum two-phase short-circuit current at the end =6729A.
Will be substituted into the formula (4-3):
= 6729/ 1280 = 5.2 & gt； 1.5 meets the sensitivity requirements.
Setting calculation of overload protection for 2# feed switch:
Substituting the formula (4- 1) gives: 1. 1×62=67A.
Setting value of overload protection =67A.
Setting calculation of short-circuit protection for 2# feed switch:
The setting value of short circuit protection is 6 ~ 8 times that of overload protection;
Setting value of short circuit protection =67×8=536A.
Sensitivity verification of 2# feeder switch protection device:
The minimum two-phase short-circuit current at the end is = 1 164A by looking up the table.
Will be substituted into the formula (4-3):
= 1 164/536 = 2. 17 & gt； 1.5 meets the sensitivity requirements.
Setting calculation of overload protection for 3# feed switch;
Substitution formula (4- 1) is:1.1×153 =168a.
Setting value of overload protection = 168A.
Setting calculation of short-circuit protection for 3# feed switch:
The setting value of short circuit protection is 6 ~ 8 times that of overload protection;
Setting value of short circuit protection = 168×8= 1344A.
Sensitivity verification of 3# feeder switch protection device:
By looking up the table, the minimum two-phase short-circuit current at the end is =6370A.
Will be substituted into the formula (4-3):
= 6370/ 1344 = 4.7 & gt； 1.5 meets the sensitivity requirements.
2, low voltage switch setting table
Table 5:
Switch serial number Switch model Switch serial number overload setting (1) Short circuit setting (1)
1kbz 16-400 160 1280
2 kbz 16-400 67 536
3 kbz 16-400 168 1344