Designing Of The Intermediate Frequency Source For Electric Heating Oil Recovery

Intermediate frequency electric power supply is a kind of static electricequipment transferred from three phase 50 Hz industrial frequency source supply to300-800HZ intermediate frequency electric power supply, which is specially used inoil recovery by wellbore electric heating and heavy oil pipeline transportation heating.It is characterized by electricity saving and high heating efficiency compared to theelectric heating oil recovery by industrial frequency source supply.The heating theoryof the intermediate frequency is the surface effect and proximity effect.In order to solve the problem that large energy consumption and low heatefficiency are commonly occurred in electric heating oil recovery, the study focuseson designing of the new driving loop, IGBT, transformer, etc. in order to meet therequirements of stable running, wave form and life-span in the field site, based on theanalysis and investigation on the practical data of industrial frequency supply andsome of electric heating by intermediate frequency source.In the paper, the main loop of the intermediate frequency source is designed ,based on the working mechanism and designing principles of the intermediatefrequency source, including designing of three phase uncontrollable rectifying circuitwith capacitance filtering , voltage type inverse variant circuit, the circuit for thecontrolling part and terminal part, lock-out circuit and its structure as well asintermediate frequency transformer .Through processing the model machine, installation and calibration, simulationtest and field test, repetitive experiment and modification, many problems found inthe early development stage are solved including IGBT stability, mis-movement oflock-out, heating, transformer temperature rising and electro-magnetismcompatibility, etc..Designing of the intermediate-frequency source for electric heating oil recoveryis based on the principles of utility and stable performance. The main part of thesource is composed of large power electric elements, which could bear large voltageand current. The controlling part of the source is of the one-chip with rich programorders, characterized by fast running, flexible control, large output power, easilyvarying running frequency, reasonable protection configuration, structure suitable forfield environment. Closed loop system has improved the automation degree. So thewhole system operates stably. Through field trial test, the heating effect is satisfactoryand achieved expected effect for energy saving. For electric heating oil recovery, theintermediate frequency source and its matched equipment have great advantages inthe heavy oil recovery, which has promising market.