CN101852747A - Design method of constant-frequency gas-insulated X-ray flaw detector - Google Patents

Abstract

The invention discloses a design method of a constant-frequency gas-insulated X-ray flaw detector. The design method comprises the following steps of: (a) designing a high-voltage wire package of the X-ray flaw detector and a filament wire package of an X-ray tube to share one iron core to reduce the turns of a filament wire package; (b) forming a oscillation circuit by using distributed capacitors and distributed inductors existing because a X-ray generator is formed by connecting a high-pressure transformer (comprising a filament transformer) and the X-ray tube in parallel, wherein the oscillation circuit has an optimal resonance point so that the output voltage frequency of a control part is adjusted and fixed on the resonance point while the X-ray generator is transformed into a purely resistive load; and (c) stabilizing a ray tube current by adjusting the pulse width of the output voltage frequency of the control part because of the reduction of the filament turns. The invention changes the design idea of the X-ray flaw detector of the modern variable-frequency industry, overcomes all defects of the variable-frequency flaw detector so that the constant-frequency flaw detector can save electricity over 40 percent and has great through thickness, high sensitivity, little dispersion and environmental protection.

Description

The method for designing of constant-frequency gas-insulated X-ray flaw detector

Technical field

The present invention relates to the industrial flaw detection machine, especially relate to the method for designing of constant-frequency gas-insulated X-ray flaw detector.

Background technology

X-ray flaw detector will be adjusted the X-ray tube both end voltage according to the thickness of detected steel plate in the industrial nondestructive testing process.In order to satisfy little, in light weight, the portable needs of volume, x-ray flaw detector all is designed to a shared iron core with the filament transformer of high-tension transformer and ray tube at present, for when adjusting voltage, filament voltage is constant, and it has adopted the way of frequency modulation to realize.Because x ray generator is inductive load, therefore have the following disadvantages, mainly show as: one, voltage adjusting range are narrower, film making penetration thickness scope narrows down; Two, electric current is big, power consumption is high, and causes hi-line bag and ray tube thermal value fragile greatly; Three, because the diffusing dosage that shines of the variation X ray of frequency conversion is bigger, sensitivity is lower, and environmental pollution simultaneously is comparatively serious.

Summary of the invention

The invention reside in provides a kind of energy-conserving and environment-protective, the big method for designing that detects sensitive high constant-frequency gas-insulated X-ray flaw detector of penetration thickness.

For achieving the above object, the present invention takes following technical proposals:

The method for designing of constant-frequency gas-insulated X-ray flaw detector of the present invention, undertaken by following step:

A, the hi-line bag of x-ray flaw detector and the filament wire bag of X-ray tube are designed to totally one iron core, the filament wire bag number of turn reduces;

B, because x ray generator is to be formed in parallel by high-tension transformer (containing filament transformer) and X-ray tube, also just have distributed capacitance and distributed inductance, and form oscillation circuit, an optimum resonance point is arranged in the oscillation circuit.If the frequency of the output voltage of control section is transferred on the tuning-points is fixed up, this moment, x ray generator became pure resistive load (voltage and current waveform size, phase place identical);

C, because the minimizing of the filament number of turn can realize constant ray tube current by the pulsewidth of adjusting the control section output voltage frequency.

The invention has the advantages that the design concept that has changed existing frequency conversion industrial X-ray diagnostic machine, overcome all deficiencies of frequency conversion defectoscope, make the constant frequency defectoscope to economize on electricity more than 40%.And penetration thickness is big, and is highly sensitive, the few environmental protection of scattering.Owing to take existing x ray generator is become resistive load by original inductive load, reduce the filament transformer number of turn, therefore can be by increasing the interference that pulse width reduces higher hamonic wave.In order to further specify the marked improvement of institute of the present invention tool, the present invention is with rated capacity 250KV, and 5MA provides constant frequency and frequency conversion x-ray flaw detector main performance contrast table (supply voltage 220V/50HZ).

Contrast table:

Constant frequency x-ray flaw detector frequency conversion x-ray flaw detector

Voltage is adjusted 85kV-250kV voltage and is adjusted 150kV-250kV pulse-width adjustment 2.4ms-1.2ms frequency adjustment 250Hz-160Hz constant frequency 110Hz ± constant pulsewidth 1ms ± power output 250kV * 5mA=1250W power output 250kV * 5mA=1250W input power 220V * 6.6A=1452W input power 220V * 12A=2640W power attenuation 1452W-1250W=202W power attenuation 2640W-1250W=1390W detection sensitivity≤1% detection sensitivity 〉=1.8%

As can be seen from the above table, with the x-ray flaw detector of power, the reactive loss of constant frequency x-ray flaw detector has reduced more than 1,000 watt, and sensitivity improves nearly one times, has therefore improved accuracy of detection (anti-flase drop) greatly, the little and environmental protection of scattered quantum simultaneously.

Description of drawings

Fig. 1 is the constant-frequency gas-insulated X-ray flaw detector schematic block circuit diagram of making according to method for designing of the present invention.

Embodiment

The method for designing of constant-frequency gas-insulated X-ray flaw detector of the present invention, undertaken by following step:

A, the high-tension transformer of X ray industrial flaw detection machine and the filament transformer of X-ray tube are designed to a shared iron core;

B, because x ray generator is an inductive load, there is the resonant tank of being made up of distributed inductance and distributed capacitance in its, therefore, the frequency of impressed voltage is adjusted into the resonance frequency of described resonant tank, makes x ray generator become pure resistive load;

C, realize stablizing the tube current of X-ray tube by the pulse width of adjusting impressed voltage.

As shown in Figure 1, following is the constant-frequency gas-insulated X-ray flaw detector of making according to method for designing of the present invention:

1, high-voltage rectifying part

Adopt serial connection controllable silicon (SCR) single-phase half-controlled bridge-type rectifier system, controllable silicon is subjected to the triggering with current synchronous signal, and the input pulsating current is filtered into smooth direct current through LC then, and voltage is feedback input controllable silicon controller after resistance R 2 samplings.Controllable silicon controller adopts the light-coupled isolation technology, high pressure forceful electric power and low pressure weak current part kept apart, thereby in the safety that guarantees to have guaranteed under the linear condition use and maintenance personal.This controllable silicon controller adopts the reliable triggering of proportional and integral controller (PI) and integrated circuit TL494, thereby has guaranteed control voltage output accuracy.

2, electric current (mA) copped wave part

Adopt advanced high power switch tube module (IGBT), under the control of impulse regulator (PI) and integrated circuit TL494, carry out the constant frequency pulse width modulation, stable with the tube current that guarantees x ray generator.Electric current (mA) sampling is obtained by resistance R 20, R34, by the voltage follower that integrated circuit LM324 (ICI) forms itself and regulator is isolated, to guarantee the precision of control.

3, control and display part

This part most of is done unified control by microcontroller 89C51 to above-mentioned two, in time makes the control and the protection instruction of various requirement and shows on light-emitting diode display, thereby make the staff can in time understand the work at present state.This machine detects six kinds of common faults automatically and shows on display pannel.Its implication is as follows: daily x ray generator training and operation, carry out fully automatically with microcomputerized control, and need not manual intervention; machine is equipped with from shutting down one day to one month with interior automatic instruction machine program; do not establish the instruction switch, and when start automatically according to carrying out the instruction machine stop time, simplified operation.

Claims (1)

1. the method for designing of a constant-frequency gas-insulated X-ray flaw detector is characterized in that: undertaken by following step:

A, the high-tension transformer of X ray industrial flaw detection machine and the filament transformer of X-ray tube are designed to a shared iron core;

B, because x ray generator is an inductive load, there is the resonant tank of being made up of distributed inductance and distributed capacitance in its, therefore, the frequency of impressed voltage is adjusted into the resonance frequency of described resonant tank, makes x ray generator become pure resistive load;

C, realize stablizing the tube current of X-ray tube by the pulse width of adjusting impressed voltage.

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