Abstract:
A pumping jack drive system using an induction motor whose speed is controlled by a variable-voltage, variable-frequency power supply comprises means for detecting the speed of the induction motor and an instantaneous value of the secondary current; means for detecting the down stroke time for every cycle of each pumping jack; means for detecting the maximum value of the instantaneous secondary current at each down stroke; means for detecting and storing the time from each down stroke reference point to the maximum value of instantaneous secondary current, and means for setting the reference time to the maximum value of instantaneous secondary current to be compared with the stored value wherein the two are compared at the end of the down stroke for each cycle and, if the time that the instantaneous value of the second current reaches the maximum value is later than the set reference value, then a pump-off condition is considered to occur. Thus, an accurate pump-off and continuous production in an oil well can be performed.
Abstract:
This invention relates to ununiform rotary transmission and control method to improve compression efficiency and pulsation rate of object fluid by changing the velocity of suction and compression strokes in pump and compressor and improve suction efficiency and combustion efficiency of internal combustion engine by changing compression (exhaust) and explosion (suction) time. In compressor and pump, the rotation angle of driving rod during compression is made larger than that during suction, thereby reducing maximum torque of driving axle during compression and consequently getting desired result with a driving unit of small capacity. In this way, this invention improves overall efficiency and pulsation rate of object fluid, and provides internal combustion engine with conditions close to complete combustion by elongating suction and explosion time compared with compression and exhaust time.
Abstract:
A liquid pressurizing device, comprising a plunger pump (1), a pressure sensor (23), and a pressure control part (25) which moves plungers (5A, 5B) so as to make an actual delivery pressure value reach a predetermined threshold and, after the acual delivery pressure value reaches the threshold, controls the actual delivery pressure value so as to determine an optimum feedrate, and then maintains the optimum feed rate at a constant, wherein the pressure control part (25) comprises a proportional element which, after the actual delivery pressure value reaches the threshold, proportionally controls the actual delivery pressure value while the plungers (5A, 5B) first reach the forward ends thereof.
Abstract:
A presente invenção refere-se a um sistema e a um método de controle para pistão de compressor linear ressonante (100) especialmente projetados para operar na sua máxima eficiência, sendo tal sistema capaz de acionar o dito compressor sem o uso de sensores para medir grandezas ou variáveis mecânicas. A presente invenção faz referência ainda a um método de controle para pistão de um compressor linear ressonante, cujas etapas permitem estimar a velocidade e o deslocamento do referido pistão, a fim de controlar de forma eficiente o motor do compressor. Adicionalmente, a presente invenção refere-se a um compressor linear ressonante (100) dotado de um sistema de controle tal como proposto no objeto ora reivindicado.
Abstract:
Dosierpumpenaggregat mit einem Dosierraum (6), einem diesen begrenzenden, durch einen Verdrängerantrieb (22) bewegbaren Verdrängerkörper sowie einer Steuereinrichtung (30) zum Ansteuern des Verdrängerantriebs. Die Steuereinrichtung ist derart ausgebieldet, dass sie zumindest in einem bestimmten Betriebszustand den Verdrängerantrieb derart ansteuert, dass ein Hub, insbesondere Druckhub, des Verdrängerkörpers mit einer ersten geringen Hubgeschwindigkeit begonnen wird und im weiteren Verlauf des Hubes (36) die Hubgeschwindigkeit auf eine zweite erhöte Hubgeschwindigkeit erhöht wird. Verfahren zur Steuerung des Verdrängerantriebs eines solchen Dosierpumpenaggregates.
Abstract:
A method and system for pumping unit with an elastic rod system is applied to maximize fluid production. The maximum stroke of the pump and the shortest cycle time are calculated based on all static and dynamic properties of downhole and surface components without a limitation to angular speed of the prime mover. Limitations of structural and fatigue strength are incorporated into the optimization calculation to ensure safe operation while maximizing pumped volume and minimizing energy consumption. Calculated optimal prime mover speed is applied to the sucker rod pump by means of beam pumping, long stroke or hydraulic pumping unit by controlling velocity, acceleration and torque of the electric prime mover or by controlling pressure and flow rate in hydraulically actuated sucker rod pumping system.
Abstract:
A motor speed controller (100) identifies the position of a pump rod (14). At one or more critical positions of the rod, the motor speed controller (100) adjusts the speed of the motor to change the movement of the pump rod (14). The critical positions and the rate of change of speed at each critical position can be user-specified.
Abstract:
A linear compressor drive device (101) comprising an inverter (2) for supplying a drive current of a specified frequency to a linear compressor (100), wherein an inverter controller (6) is provided to control the inverter (2) so that the frequency of an output current therefrom is a resonance frequency based on resonance frequency information and to measure the instantaneous values of the output current Id and output voltage Vd of the inverter (2) at a phase timing that renders zero a change in the output current Id of the inverter (2) to thereby calculate a piston stroke from the measured values. Such a linear compressor drive device (101) can detect accurately the piston stroke and top clearance of a linear compressor by a simple processing without using a position sensor.