Oszacowanie wyważenia zespołu pomp żerdziowych bez żurawia na podstawie wartości zużywanego prądu

Abstract

The article presents the results of experimental studies to assess the loading and balancing of a new constructive solution of beamless sucker-rod pumping units. It is noted that the key factor that has the most significant effect on the mean time between failures (MTBF) is the right balancing of the pumping unit. The main purpose of the balancing device is the accumulation of potential energy during the downstroke and its release during the upstroke of the rod. It has been proved that the proposed additional balancing system (movable counterweight) which helps to reduce the uneven load on the electric motor and the power consumption of the pumping unit will also increase the efficiency of the beamless sucker-rod pumping unit. It was found that losses in sucker-rod pumps depend on the degree of balance of the counterweights. If the unbalance coefficient of the equipment is in the range from –5 to +5%, then the power loss due to unbalance can be ignored. In the current article, the authors propose a technique that allows to determine the energy characteristics of the electric drive of the pumping unit under conditions of a cyclically changing load and insufficient balance. It was revealed that when the balancer head passes from the upstroke to the downstroke and vice versa, there are sections with a negative value of the torque, which is explained by the influence of the inertial forces of the moving masses. This leads to shocks in the gearing of the reducer at the extreme positions of the cranks, increased wear and possibly to breakage of the teeth. Since it is not possible to completely eliminate this phenomenon, one should strive to limit the value of the negative torque by the correct balancing of the sucker-rod pump. In all cases, the change in the operating mode of a new constructive solution of beamless pumping unit requires new calculations, and requires changing the position and weights of movable and rotary counterweights (with combined balancing).