Oil pumper cycle speed change drags energy conservation
The present invention relates to the beam-pumping unit and the electric drive technology thereof of oil field oil recovery usefulness, especially relate to a kind of oil pumper cycle speed change and drag power-economizing method.
Advantages such as that beam-pumping unit has is simple in structure, cheap, maintenance cost is few, since half a century, oil field both domestic and external all is extensive use of, however it also exists than important disadvantages.Oil pumper is the equipment of heavy-load start and long-term light running, the output characteristics that belongs to AC torque motor, but AC torque motor of the prior art is by increase rotor loop resistance value superfluous slip power to be changed into the mode that dissipates behind the heat energy to realize required torque characteristics, because of its a large amount of heatings of rotor loop resistance very ambassador, force motor designs to get that volume is big, cost is high, add again that operational efficiency is low and make it can not be used to drag oil pumper equipment.
Therefore, since half a century, the oil field is to use common mouse-cage type 6 utmost points and 8 utmost point asynchronous motors to drag oil pumper always, because the starting torque of common mouse-cage type 6 utmost points and 8 pole motors has only the twice nominal torque, for making the oil pumper normal starting, need press the specification of the starting torque apolegamy motor of oil pumper, the average load rate of motor has only about 30% when starting afterwards normally operation, causes the situation of serious " low load with strong power ".The motor of used for oil extractor is by belt pulley, gear-box, crank axle and four connecting rods etc., the up and down straight reciprocating motion of the low speed that converts motor to suspension point at the high speed rotary motion under the rated speed, now the common cage electromotor of Y series (IP44) that uses can only be under rated speed could long-play, the constant speed of motor rotatablely moves, soft commutation by crank axle mechanism converts speed to by sinusoidal rule, from zero to peaked speed change linear reciprocating motion, long draw by last km passes to the down-hole swabs, reaches the purpose that extracts oil; This traditional straight line variable motion oil pumping mode is difficult to make the swabbing parameter of down-hole piston pump to be tending towards rationally and the minimizing pump leakage, and further raising oil pump efficient is restricted.Because the driven off by shaft characteristic properties of crank, make the hurried variation of its rectilinear motion speed ratio, motor is dragging for a long time from zero load and is moving under maximum load periodically pulsing condition, add the drive line angle of the continuous variation of four jointed gear units formation, cause the reach of pulsating load peak value again and produced negative torque phenomenon, the load characteristic of oil pumper is further worsened, can't realize the complete equipilibrium operation of oil pumper by the adjustment counterweight, thereby the energy index of motor is descended significantly, the operational efficiency of the Y series motor that 90% operational efficiency is arranged is originally dropped to about 65%, Y series power of electric motor factor is dropped to about 0.4.
Oil pumper is a kind of heavy-duty machinery, inertia load torque during starting is very big, add that motor is to operate under the periodically pulsing loading condition, force supporting motor specification all bigger than normal, the starting current that causes motor is when operation 17～19 times of average current, the needs of big electric current when satisfying motor starting, the power supply unit capacity also will the corresponding increase with the increase of motor power (output).
When motor of oil extractor moved at zero load or near zero load, not only motor wasted electric energy, and the power supply units such as oil well dedicated transformer of unit power supply also waste electric energy.
For a long time, the speciality circles of each the countries concerned of the world are making great efforts to solve the low problem of oil pumper operational efficiency always, have also developed multiple new product; During the domestic recent two decades because oil well quantity surge, improve oil recovery efficiency and reduce cost for oil production and be much accounted of, domestic the departments concerned has also dropped into a large amount of funds, man power and material to improve the operational efficiency of oil pumper, yet till now, fail the technical scheme that finds reality to address this problem effectively all the time.
Summary of the invention
One of purpose of the present invention provides a kind of poor efficiency that can make beam-pumping unit and extracts and become the periodically high efficiency abstracting method that drags of speed change of motor.
Two of purpose of the present invention provides the induction conductivity of a kind of and existing equal-wattage and number of poles and compares under the condition that starting current does not increase, export five times of left and right sides nominal torques and the inertia load by stepless automatic speed-changing function and oil pumper intercouples, and the pulsating load that will become torque is converted into normal continuous load, reaches the starting that highly adapts to oil pumper and the high efficiency ac motor of operation characteristic.
Oil pumper cycle speed change of the present invention drags power-economizing method and is achieved in that it comprises beam-pumping unit, rod pumping pump and induction alternating current (AC) motor, motor passes through belt pulley, gear-box, crank axle and four connecting rods etc. rotatablely move the constant speed of motor and convert linear reciprocating motion to, when whenever going around the soft commutation of twice transmission speed the highest forming and twice, the crank axle on the oil pumper puts this intrinsic characteristic by zero velocity, make the load torque of oil pumper periodically change to torque capacity from zero torque, change to zero torque from torque capacity again, it is characterized in that: every phase stator winding of induction alternating current (AC) motor all is made into shunt-resonant circuit under several different rotating speeds by switch and several groups of AC capacitors respectively, on the motor rotor each is in the shared groove number of magnetic pole, the insulation winding of seven to ten two-phases all is set, the output characteristics that makes motor expeditiously, the harmful inertia load that produces when moving with oil pumper intercouples, and the pulsating load of oil pumper is converted into normal continuous load.When the required torque of pump load reduced rapidly, motor speed rose significantly, and the excess power of motor output is stored in the transmission system of oil pumper by inertia load, became inertia kinetic energy; When the required torque of oil pumper increased rapidly, motor speed descended rapidly significantly, and the kinetic energy that is stored in the transmission system is discharged, and the power addition of exporting with motor drags swabs jointly.Like this load of motor just become continuous, and under the pulsation peak load about 0.6 times high-efficiency operation.
Proved all that by test of many times and theory analysis the three-phase alternating current inductiopn rotor of low induced potential also has the character of dc motor rotor.Because on the rotor of induction alternating current (AC) motor with each to all being provided with seven heterogeneous insulation windings more than mutually in the shared groove number of magnetic pole, wherein each mutually the shared air-gap flux of system group all be the part of every utmost point rotor flux, because magnetic flux is little, the electromotive force and the electric current that are generated when flux change weekly are all less, therefore, constituted a rotor magnetic pole that magnetic potential is more weak, when rotor magnetic potential and the coupling of stator magnetic potential, its synthetic magnetic flux vector is the enhancing shape resultant magnetic field based on the stator magnetic potential, the character that this has just fundamentally changed the induction alternating current (AC) motor rotor magnetic potential makes its characteristic trend towards the character of dc motor; Overcome to induct high potential and produce the phenomenon of very big commentaries on classics stator current of the alternating current impression rotor that under high-slip, moves, realized that the induction alternating current (AC) motor rotor also has higher-wattage group's number and high efficiency purpose when moving under high slip, realized motor starting torque M under the condition that starting current does not increase simultaneously
QReach the starting performance of 5 times of left and right sides nominal torques.
Its subordinate is characterised in that:
1. induction alternating current (AC) motor rotor winding also is included in each in the shared wire casing of magnetic pole, nine adjustable, two-layer composite with its turn ratio of ten two-phases mutually, the insulation winding that two covers respectively independently have the loop mutually of one's own that are provided with simultaneously, these windings are made of single or many flat, circular copper wires.
2. realize regulating respectively oil pumper upstroke speed or down stroke speed by the method for regulating oil extractor balance weight,, improve oil well output to reduce the stroke that sky is taken out, and conservation of power and maintenance cost.
3. when zero torque changed, motor speed raise oil pumper from torque capacity, had compensated because the problem of the swabs stall that the crank axle transmission causes has reduced oil pump returning under low speed and leaked.
4. the stator winding of three-phase alternating-current induction motor, each is that two insulation windings of 1: 3.5 ± 0.85 constitute by turn ratio all mutually.Can make the starting torque of motor reach 5 times of specified turnovers in the left and right sides, can make motor high operating efficiency be arranged between speed-change area again.
The invention has the beneficial effects as follows:
1. the power-economizing method that drags of beam-pumping unit cycle speed change, can be when existing conventional pumping unit keeps the advantage of commutation, make the extraction speed of swabs more reasonable, thereby optimized the operation characteristic of oil pumper, can significantly improve complete machine operational efficiency and a large amount of saves energy of oil pumper.
2. the speed change of oil pumper drags, and can reduce the load peak of V belt, gear-box and rolling bearing, can reduce power consumption and improve reliability, also can reduce the application life of maintenance cost and prolongation equipment simultaneously.
3. the heavy-load start of oil pumper and the big starting torque ac motor of operation characteristic be can highly adapt to,, the operational efficiency of supply transformer and the investment of the equipment of saving improved owing to, can reduce the capacity of power supply unit because starting current is little.
4. the high-efficiency electric motor of big starting torque, when changing supply voltage, can form a high performance motor with stepless speed regulation, the time of step-less adjustment jig frequency and the upper and lower stroke of step-less adjustment thereby the realization oil pumper is in operation, at any time the jig frequency of stripper well, heavy oil wells is regulated and control, so that oil pumper operates in optimum Working, improve oil production, reduce cost for oil production.
Description of drawings
The present invention is further described below in conjunction with drawings and Examples.
Fig. 1 is big starting torque ac motor and the torque characteristic curve of common Y series 18.5kW6 utmost point ac motor and the comparison diagram of current characteristics curve of 18.5kW 6 utmost point oil pumper special uses.
Fig. 2 is the fluctuating load torque curve of the beam-pumping unit after overbalance and drags method by the periodicity speed change, makes it become the continuous load torque of 55% left and right sides peak value
The torque characteristic curve of the special-purpose big starting torque motor of 1. a kind of 18.5kW 6 utmost point oil pumpers of the present invention among the figure, 2. the current characteristics curve of big starting torque motor, 3. the torque characteristic curve of common Y series 18.5kW 6 utmost point ac motors, 4. the current characteristics curve of common Y series 18.5kW 6 utmost point ac motors, 5. the fluctuating load torque characteristic curve of beam-pumping unit 6. makes fluctuating load torque convert the characteristic curve of continuous load torque to by the periodicity speed change method of dragging.
The specific embodiment
The system that the speed change of the beam-pumping unit method that drags is made up of following each several part realizes.
Be arranged on the needed power of long piston pump of oil well bottom, be moving from the surface well oral instructions by the long draw of last km, the wire rope that is fixed on the pull bar upper end is in transmission connection with walking beam, the other end of walking beam is in transmission connection with two crank axles by crossbeam and two long connecting rods, and then by these heavy components such as heavy reduction box and big belt pulleys, and several ton heavy large-scale counterweight and the induction alternating current (AC) motors of going up that are contained on the crank axle are in transmission connection.Because the inertia of whole drive system is big especially, when oil pumper starts, motor is except providing Liquid extracting and promoting the required load torque, also must provide the bigger transmission system that makes to quicken required inertia load torque, can the size of its concrete torque be according to the starting process that finish oil pumper at motor in the not overheated time.
Use a kind of that two of purpose of the present invention provided, 18.5kW the big starting torque ac motor of 6 utmost point oil pumper special uses, its starting torque is seen the curve (1) of Fig. 1, it can provide 1016Nm the starting torque of (model machine measured value), be 5.8 times of common Y series 18.5kW 6 utmost point ac motor nominal torques, starting torque than Y280M-55kW 6 pole motors that use on the present oil pumper is also big, can replace 55kW 6 pole motors make the oil pumper normal starting with this light-weighted fractional electric motor, and under high-efficiency operation nominal load under 75% left and right sides nominal load high-efficiency operation.Because the maximum starting current of this big starting torque definite-purpose motor, curve among Fig. 1 (2) is 37.5% of common Y series 55kW 6 utmost point ac motor 584A starting currents for 219.5A (model machine measured value), its cranking performance rating is about original 2.7 times. calorific value and the temperature rise of motor in starting process descends along with the minimizing of its total losses, time that therefore can the big starting torque motor starting procedure of proper extension.For example with the time lengthening 30% of starting process, just can make the original oil pumper that could start with Y315S-75kW 6 pole motors, with seat No. is that the 18.5kW 6 very big starting torque motor of 225M carry out normal starting, and long-time running is in 18kW～20kW power bracket.In addition, because the starting current of starting oil pumper is dropped to the 219.5A of 18.5kW by the 783A of 75kW motor, only be 28% of the former starting current, the capacity that this just can make the shared supply transformer of several oil wells or suitably reduce individual well supply transformer and electric power system.
The load torque of beam-pumping unit, the curve among Fig. 2 (5) is the low principal element of various motor operational efficiency that causes oil pumper to use.The way of finding the solution this problem is, the periodically pulsing load torque is changed into the continuous torque of 55% left and right sides peak torque of curve among Fig. 2 (6), the load factor of motor is under 80%～50% rated power condition all the time moves.The necessary condition that makes the fluctuating load torque of oil pumper change into the continuous load torque is, a kind of its rotating speed that can make expeditiously utilizes the inertia load in the oil pumper transmission system to carry out energy storage along with the motor that the load torque size of oil pumper is inversely proportional to and changes.According to the curve among Fig. 2 (5), when the load torque of oil pumper descends rapidly, the inertia that the superfluous torque of the part of motor output is used to quicken the oil pumper transmission system, the instantaneous speed of service of compensation suspension point converts electric energy to kinetic energy and is stored in the transmission system.When load torque rises rapidly, the rotating speed of motor is along with decline, the kinetic energy that is stored in the inertia system is discharged, drag the swabs operation jointly, the load factor of motor is in 80%～50% the high-efficiency operation interval all the time with motor output torque addition.