High-voltage frequency conversion energy-saving retrofit design of mine screw air compressor system Nan Yonghui, Li Junwei, Pengli Zhuzhou Converter Technology National Engineering Research Center Co., Ltd., Hunan Zhuzhou 412001 system basic structure and working principle, as well as application notes and Experimental data and energy saving analysis are given.
1 Overview High-power screw air compressors provide gas for underground pneumatic equipment. The annual power consumption is very considerable. Because there are many underground equipments, the wind time is not fixed, the air volume is unstable, so the air compressor must run continuously. . When the amount of air used in the underground is small, it will cause the air compressor to run for a long time under low load, the power loss will increase and the wear of the equipment will be aggravated, and the running cost will be increased. If the equipment is shut down or some equipment is shut down during the load, it will lead to frequent operation, shorten the life of the equipment, and will affect the use of wind equipment and the wind, and the cascading multi-level pressure converter that has appeared in recent years has been dragged high. The melon power motor scheme has the advantages of no impact on the power grid, high energy-saving effect, significant output harmonics and low input power factor, and has become the mainstream trend of development.
Henan Coal Chemical Group crane, two sets of screw air compressor drive system under the mine, to provide pneumatic power for underground equipment, the original, frequency direct start, long-term 1 frequency constant speed record, there is a large amount of start-up current, large energy waste Disadvantages such as unstable gas pressure, after analysis and argumentation, decision-making, technical transformation, and the use of technologically advanced systems to improve economic and social benefits, Mu Wentu should introduce the frequency conversion transformation process.
2 The working mode and dragging scheme of the original screw air compressor The working mode of the screw air compressor is the main working mode of the screw air compressor is to start and stop loading and unloading, the inlet port is set with the loading valve, and the solenoid valve is loaded to control The switch of the inlet valve. When the air compressor is running, if the exhaust pressure is lower than the lower limit of the set target pressure, the pressure controller controls the load solenoid valve to be energized, and the valve is opened, and the press is at full load if the exhaust pressure is high. Set the upper limit of the standard 1 force. Then the air compressor controller commands the loading of the solenoid valve to lose power, thereby closing the port valve, and the air compressor is in a no-load unloading state. At this time, the compressor is actually an empty-transporting air compressor loading and unloading control mode so that the pressure of the compressed gas EPmill1JPm , change back and forth = is to knock down the low force value, that is, the minimum pressure that can ensure the normal operation of the compressed air user. Under normal circumstances, the relationship can be called 1+5, 5 is a percentage. If the value is roughly between 1025 and the frequency regulation technology is used to continuously adjust the air supply, the pipe network pressure can be maintained at all times. To meet the pressure of gas supply, that is, the original power frequency dragging device scheme near the corpse is two sets of rotary screw air compressor drive systems with the same parameters. The asynchronous motor drives the air compressor to rotate, the air compressor and Its control system compresses air to supply air to the downhole pneumatic equipment.
Asynchronous motor parameters rated voltage 6, rated current 43. In, the amount of power 375.
The operation of the air compressor system is as follows: the equipment is running, and the equipment is reserved; if one equipment fails, it will be out of operation and another equipment will be started.
In order to improve the operating life of the air compressor transmission equipment and facilitate maintenance, the two equipments are turned down every second to turn the operating equipment into standby equipment, and the standby equipment is turned into operation.
Pneumatic equipment with a gas pressure greater than 06 cubits 3 can work. There are several gas peak points in the downhole equipment. When the gas is low, the downhole pressure is high. The air compressor flapping system has the adjustment force of the unloading mode. The short adjustment accuracy is not high and the solenoid valve frequently operates. The output force of the actual day is between 0.60 and 0.75 PCT.
The motor runs at a constant frequency of 50, 2 at a constant speed, and the average rated current is 38 people; The current can reach 200, and the average power is about 310.
Analysis of the technical system of the system, the original motor drive system has a downward adjustment of the speed and pressure, so the original system has a waste of energy, the use of frequency control is feasible.
3 The high-voltage frequency conversion of the air compressor is considered by design redundancy, and the company chooses 150 42-type 6 power unit cascades. According to the characteristics of the mine pneumatic equipment system, the system adopts 1 force closed loop, the given pressure is 0.62. The inverter has built-in digital (1) Tuner. On the inverter interface, only the pressure given inverter can be set to adjust the output frequency to stabilize the pressure. .
1 Inverter retrofit electrical scheme Variable frequency electrical main wiring 1. Medium 1. Start 1 circuit breaker, 2 2 = start cabinet circuit breaker, furnace 1 furnace 6 for manual isolation Kaiai. The furnace 5 and the still 2 are mechanically interlocked; the 4 and the suction 1 are mechanically interlocked; the furnaces 6 and 53 are mechanically interlocked; the sheets 5 and 54 are interlocked by the sequence lock, and the 82 and 51 are interlocked by the program lock, When selecting 1 high-voltage motor frequency conversion operation, the switch operation needs to be turned off and the switch is still 10, and the combination is still 5. It is still 6, and 1 is the same. When the inverter is equipped with 1 motor, if the inverter needs to be operated and overhauled, it will be disconnected. 2 knowledge, so that the 2+ frequency drag uses the variable speed control scheme, the reliability of the equipment can be improved.
6 bus high voltage motor 2 high voltage motor 6, high voltage inverter consists of 6 power units per phase 2 only 3 modules are drawn per phase. The multi-level high-voltage frequency converter is mainly composed of a phase shifting transformer power unit and a controller as described in the bypass switch cabinet 1. System structure 2. The phase-shifting transformer has 6 windings per phase. 2 Only 3 are drawn per phase, and the windings are sequentially shifted by 10 to achieve 36-pulse rectification. The output of the phase shifting transformer is connected to each power unit, and the controller drives each power unit through the optical fiber. The unit of the human phase is connected to the phase shifting transformer, 8, which is the same. The power single-phase mountain-phase bridge rectifier and bridge inverter are composed. It can be seen that the DC voltage after rectification of each unit is independent, which is advantageous for the control of 1 and each phase is superposed by high voltage to high voltage. Each power unit is also not shown in the bypass control. When a unit appears, the unit is bypassed, and the remaining units can continue to operate. The balance is controlled to make the output line, 1 maintain balance. This enhances the reliability of the system. The phase shifter is the motor speed, the stator frequency is the motor slip rate, and the household is the motor pole pair. For the asynchronous motor, the household is fixed, the adjustable range of 5 is also small, and the variable range is large, so the adjustment is the most important speed regulation method. According to the motor theory, in order to maintain a constant torque capacity, it is necessary to maintain the magnetic flux density substantially constant, so that the ratio of the stator electric power to the stator frequency must be kept substantially constant, that is, under variable voltage frequency conversion control.
The multi-level frequency converter adopts the 1 carrier phase shift 501 control technology. The basic principle is that each phase consists of cascading units. The phase of each single-angle carrier is sequentially and 36,1 uses the same sine in phase. Modulation Yi 4, using the waveform generation method in the 81 fly 1 technology and the waveform superposition structure in the multiplexing technique to generate 5 waveforms, thereby realizing the name level 5 output; the reference waves between the 30 phases are sequentially different by 120. For each phase Inverter with cascaded module units, the maximum number of phase voltage levels is 2 + The maximum number of voltage levels is 4+. The more cascading modules, the closer the output waveform is to the sine wave, which is beneficial to reduce the number of And 1 is the 6th unit cascade output line, it can be seen that the output waveform is very close to 1 string.
Frequency conversion design and use instructions analysis and testing. Set the high frequency conversion system as the force closed loop, the caller enters the given version of the recommended force value 621 in the interface; the inverter has built-in digital, 10 regulator, the output of the regulator is the output frequency of the given motor, and the actual force is adjusted by frequency modulation. The small, negative feedback regulator increases the output frequency to increase the force to maintain a given pressure; when the actual pressure is high, the negative feedback regulator reduces the output frequency and reduces the force to reduce energy consumption.
Force deceleration time setting. It is necessary to satisfy both the process requirements and the system reliability. If the acceleration time is set too small, the large slip rate during startup or acceleration will cause excessive current. Similarly, if the deceleration time is set too small, during the deceleration process, the motor is charged to the inverter in the generator state, which can cause the module capacitor voltage to be too high, which affects the system reliability. After the test and analysis, the local system accelerates when the 60150 deceleration time 120300 starts to be activated. The air compressor control system has pressure to judge the chat before starting, so the inverter must wait until the pressure is 0.451 inch before starting.
The sequence of isolating switches and circuit breakers must be correct. After the frequency conversion is used, the motor shaft temperature drops due to the decrease of the motor energy consumption, the original shaft temperature is 95, and the average temperature after the transformation is 80. The other friction losses are reduced, which is very beneficial for improving the service life of the equipment. The switching cycle of the air compressor is recommended to be changed. The 4 system test and energy-saving calculation system are debugged on site and the test waveforms are collected.
Flow waveform. 5 is the steady state 36 current output waveform.
2, the output current waveform can be seen from 4, the starting current is small, the middle has a large amplitude peak peak of about 7, people, its vibration is due to the motor like low frequency vibration phenomenon, the motor between 712 vibration. Because the inverter has current feedback suppression measures to make the motor run in a safe range, it is far superior to the original power frequency direct start process. 5 is the current waveform current effective value when the motor is running stably at 3682. It can be seen that the current sinusity is very good and the output harmonics are small, which is very beneficial to the motor.
Between 3, the average rated current of the motor 1 is 38 people; the average power is 310kW. After the inverter is operated, the pressure is basically 0.60.653, the average motor current is 32, the input average current is 23., and the average power is 2001. If the year is calculated according to the work 3501, the total energy can be 10,000.
Therefore, the high-voltage frequency converter is used in the mine screw air compressor to realize the soft start of the air compressor system, which greatly reduces the advantages of equipment maintenance and repair costs, and the actual operation is clear, which not only improves the reliability, but also the mechanical damping on page 84. Delay mechanism principle 1. When the grid is out of pressure or undervoltage, the screw on the core of the loss-relief coil is treated by spring force. After the high-claw explosion-proof power distribution device pushes the isolation switch, the lost claw line is charged by the voltage transformer 6100, and the pressure-relief coil core overcomes the spring force, and drives the transmission shaft to move to the fixed position, when the power grid loses pressure or When the voltage is under voltage, the voltage loss coil loses power, and the transmission shaft moves downward due to the force of the lost line, and the shaft of the mechanism is extended. The three steel balls, the small groove on the drive shaft, make the transmission shaft slowly move down; and the pressure between the steel ball and the transmission shaft is caused by the friction between the steel ball rear spring and the steel ball to slow down the transmission shaft. , to achieve the purpose of delay. After the transformation, when the excitation coil is energized, the electromagnetic force overcomes the spring and the system reaction force to pull the armature and pushes the load action. At this time, the ten mechanical damping delay mechanism adds 1 transmission shaft to the armature; 2 shaft seat; Steel ball; 4 adjustment spring; 5 adjustment screw and energy saving effect is significant, with obvious direct and indirect economic benefits.
1 Xiao Fu. The application of frequency conversion closed-loop regulation control system in air compressor 0. Coal Mine 21 Li Guohua. Research and development of screw compressor air compressor control system based on frequency conversion technology, 2,05.
Li Yongdong, and so on. Large-capacity multilevel converter Beijing Science Press, 2005.
Zhang Wei, continued Ming near, Yang Mei. High-pressure high-power AC frequency conversion speed control technology. Beijing Mechanical Industry Press, 2006.
B Nan Yonghui, Luo Renjun, Wu Hailin. Research on Asynchronous Motor Control Strategy Based on Cascaded Multilevel Inverter 0. Converter Technology and Electric Traction, 20085.
6 Lu Xinnan. The introduction of frequency conversion technology in the control strategy analysis of air compressor energy-saving transformation 1 piece introduction Nan Yonghui 179, male. He graduated from Beijiao Jiaotong University with a master's degree in electrical engineering in 2,6 years. Now he is mainly engaged in the application and development of high-voltage and high-power variable frequency speed control technology for power electronics.
14; responsible editor Yao Ke's action friction, increase its action time, delay the traction armature closed position, so that it avoids the large-scale stop accident caused by the momentary grid loss or undervoltage caused by the device opening.
During the start-up process, after the excitation line is energized and energized, the electromagnetic force overcomes the spring and the system reaction force to pull the armature and push the load. After the armature reaches the closed position, the steel ball lock mechanism is immediately locked, and the lock is locked in the closed position without loosening. The entire startup process is completed in an instant.
During the reset process, when the tripping excitation coil is energized, the electromagnetic force overcomes the spring reaction force to cause the shackle to touch the steel ball lock mechanism to unlock, the armature and the load are restored to the rated state under the action of the spring and the system reaction force, and the effect of the process 3 is used for the downhole high voltage. The time delay mechanism of the explosion-proof power distribution device adopts the mechanical damping delay mechanism, and there is no factor of electrical connection, and the explosion-proof of the whole mechanism is not considered. In May 2007 and September 2007, after the improved devices were used in the high-voltage explosion-proof power distribution devices of the Dingcai District of Pingdingshan No. 6 Mine and the Dingcai District, there was no trip accident. The safety performance of the organization is stable and reliable, and not only the safety level of coal mine power supply is greatly improved, but also brings considerable economic benefits.
Industrial electrical automation, direct in electrical control teaching and research work received date 200009; responsible editor Yao Ke
Furniture refers to movable objects intended to support various human activities such as seating (e.g., chairs, stools, and sofas), eating (tables), and sleeping (e.g., beds). Furniture is also used to hold objects at a convenient height for work (as horizontal surfaces above the ground, such as tables and desks), or to store things (e.g., cupboards and shelves). Furniture can be a product of design and is considered a form of decorative art. In addition to furniture's functional role, it can serve a symbolic or religious purpose. It can be made from many materials, including metal, plastic, and wood.
Metal furniture is a type of furniture that uses metal parts in its construction. There are various types of metal that can be used, such as iron, aluminium, and stainless steel.
Aluminum is a light and corrosion resistant metal,and to take advantage of these qualities, it is heavily utilized for stamped and cast furniture, especially in the category of molded chairs. Aluminum atoms form an outer layer of Aluminum Oxide, which prevents the internal aluminum from being corroded.
Metal furniture is a popular choice of furnishings, especially used outdoors for decks and patios. However, metal furniture can also be used indoors, such as brass beds, brass tables, iron bakers racks and metal curio cabinets. Besides being sturdy, metal furniture is attractive, giving a contemporary look to your home.Xinyu Mould manufacturing all types of aluminum casting furniture product HPDC dies and components.
Xinyu Mould Capabilities
-
Xinyu Mould At Glance
1.Year Of Establishment:2002
2.Location:2 (One Is Brand New)
3.Land Area:3600sqm
4.Emplyees:120
5. Equipment;CNC:18 (Makino, Toshiba, Liyang ), WEDM:10, EDM:9, Spotting Machine:2, CMM:2, Gun Drill Machine:2, Die Casting Machine:7, Others:50
-
Xinyu Mould Technical Profile
1. Engineers In 2d&3d: 16
2. Engineers In Cnc Programming:6
3.File Format For 2d: Dwg&Dxf
4.File Format For 3d:Iges&Step
5.Software For 2d:CAD
6.Software For 3d:Simens NX & Pro-E
7.Software For Programming: Powermill
8.Software For Mould Flow: Magma
-
Xinyu Mould Process Control
1.MES Process Control System
2.IATF 16949 Quality System
3.Well-Trained Operators
4.CMM Inspection
-
Xinyu Mould Advantages
1. CAE Support Magma(Lid 18175001)
2.Rich Experience In Casting Dies For Auto Structual Parts,Powertrain;Oil Pan;Redirector; AC Compressor
3.Trial Run Machines Available In House From 160t To 1600t
4.Vaccum Venting System Application In Dies
5. Partial Squeeze Skill In Dies
6.High Precision Imported CNC(5 Axis)
7.Globalized Hr Concept
-
Xinyu Mould Die Capacity
1.Max Die Size:2500*2500*1800
2.Max Die Tonnage:2500t
3.Biggest Die Casting Machine:1600t
4.Most Complex Die: 11slides
5.Yearly Capacity:350sets
-
Xinyu Mould Marketing
1.Main Market:Na;Europe;Asia
2.Main Field: Auto;Telecommunication;
Lighting;General Machinery;Power Tool
Furniture
3.Partner Offering After Sales Service:
Available In India&Us,Europe
4.Business Involved:
Aluminum Die Casting Dies
Aluminum Die Casting Components
-
Xinyu Mould Commercial Terms&Conditions
1. Fob Ningbo/Shanghai
2.Payment Term:Tt
3.For Dies:50% Down Payment 50% Prior To Delivery
4. For Castings: 10% Down Payment
The Rest Within 30days After b/l Date
5.Leadtime For Quotation:2days
6.Feedback For Customers' Query:24hours
Aluminium Castings For Furniture and other parts
Aluminium Castings For Furniture,Furniture Aluminium Castings, Aluminum Die Casting For Furniture,Custom Furniture Aluminium Castings
Ningbo Beilun XinYu Mould Manufacturing Co.Ltd. , http://www.xinyudiecasting.com