| 摘要 |
FIELD: oil production industry. SUBSTANCE: this relates to cleaning production strings of oil wells from paraffin deposits. Device for electric heating of oil-withdrawing piping of well has electric power transformer, thyristor-based frequency converter, sensor, current setting unit and regulator. Inputs of regulator are connected to current sensor and setting unit. Current setting unit gives alternating load current of required value and frequency. Current sensor is connected to input of unit for protection from asymmetric mode of operation of frequency converter, and output of protection unit is connected to frequency converter. Protection unit is made in the form of seriesly connected comparator, rectifier and filter. Additionally, device is provided with temperature sensor and temperature regulator with hysteretic characteristic and its output is connected to current setting unit, and input is connected to temperature sensor. EFFECT: higher efficiency. 1 cl, 2 dwgw |
