CN1295824C

CN1295824C - Approximate outer fluid generator for pulsed laser Q modulation

Info

Publication number: CN1295824C
Application number: CNB200410061023XA
Authority: CN
Inventors: 陈良才; 程祖海
Original assignee: Huazhong University of Science and Technology
Current assignee: Huazhong University of Science and Technology
Priority date: 2004-10-29
Filing date: 2004-10-29
Publication date: 2007-01-17
Anticipated expiration: 2024-10-29
Also published as: CN1604408A

Abstract

The present invention relates to an approximate outer fluid generator for pulse laser Q modulation, which belongs to the technical field of a laser. The present invention overcomes the disadvantages of high energy consumption, large volume, low voltage stabilization, poor sealing of a pump cavity and influence on the stable performance of the fluid of the existing extraction devices for super critical fluid SCF. In the present invention, an accumulator connected with a high-pressure pump of a pressure part is built; the accumulator is communicated with a steel cylinder storing optical fluid and is communicated with a laser Q modulation optical pool; a vacuum pump is communicated with the laser Q modulation optical pool; a circulation pump of a circulation thermostatic bath part is communicated with the laser Q modulation optical pool by a pipeline; a thermostatic bath is communicated with the laser Q modulation optical pool by a thermostatic return pipe. The present invention integrates vacuum pumping, pressurization, voltage stabilization, temperature rise and constant temperature, and has the advantages of compact structure and small energy consumption. Impurities can not jump into the optical fluid in the process of pressurization, which conveniently causes the optical fluid such as carbon dioxide, sulfur hexafluoride, etc. to achieve the approximate outer state needed by laser experiments. The temperature and the pressure of the approximate outer fluid can be adjusted at real time to meet the needs of the laser experiments for the approximate outer fluid.

Description

Pulse laser transfers Q with closely facing the outer fluid generator

Technical field

The invention belongs to laser technology field, particularly the pulse laser Q-modulating device.

Background technology

When material solid, liquid, gas three-state that people are common and laser action, all can produce nonlinear effect.But solid attitude crystal has absorption coefficient big, the shortcoming that is difficult to repair after the low and damage of damage threshold; Gas has the little shortcoming of gain coefficient because of material density is little; The characteristic of liquid occupy between gas and the crystal, but liquid has density, damage threshold and gain coefficient to be difficult for the shortcoming of adjusting because of incompressible; Thereby the common three states of matters is difficult to use in the research of high energy light laser nonlinear effect.

Supercritical fluid (SuperCritical Fluid is called for short SCF) is that state is in monophasic fluid (T＞T that critical temperature is above and critical pressure is above _c, ρ＞p _c), its density is between gas and liquid, and density is even, and diffusivity is good.Because the optical property of SCFNCP is easy to regulate, so when doing the SCF Laser Experiments, need be near the supercritical fluid (SuperCriticalFluid Near Critical Point is called for short SCFNCP or closely faces outer fluid) of critical point.But closely facing outer condition for fluid foundation is the comparison difficulty, because in known numerous materials, critical pressure and critical temperature almost do not have near the material of normality.The critical pressure height is (as CO ₂Critical pressure be 7.32MPa) or critical temperature low (as H ₂Critical temperature be-239.9 ℃).Consider to add the ratio of specific heat refrigeration conveniently, generally select for use critical temperature at normal temperature or fluid more than the normal temperature such as CO ₂Or SF ₆Set up and closely face outer condition.These fluids pour into steel cylinder with liquid state usually, so the general subcritical pressure of fluid pressure in the steel cylinder need pressurize to surpass critical pressure again to it.

The requirement of SCFNCP laser Q-switching experiment convection cell is: fluid is in and closely faces exterior domain, and fluid should quietly should not move, and fluid property is stable, fluid temperature (F.T.) and pressure may command.

In traditional SCF extraction equipment, SCF with the contacting of material in finish mass transfer and task is carried in extraction, so require SCF to circulate.SCF will become liquid through condenser earlier before advancing pump, so that the high-pressure pump pressurization heats up through heater after the pressurization again, reaches supercriticality like this.The SCF extraction equipment can only make fluid reach supercritical temperature and supercritical pressure in the mode that circulates, and SCFNCP laser Q-switching experiment to need supercritical fluid be immobilising, it is uniform and stable needing temperature, pressure etc. that related parameter is arranged, so the SCF extraction equipment is not suitable for the experiment of SCFNCP laser Q-switching.In addition, except pressurization, heating power consumption, circulate with condensation and also will additionally consume energy in the SCF extraction equipment.Also may be poorly sealed because of pump chamber, cause impurity to scurry into fluid and influence the stable of fluid property parameter.

Summary of the invention

The present invention proposes a kind of pulse laser and transfers Q with closely facing the outer fluid generator, demand at SCFNCP laser Q-switching experiment convection cell, collection vacuumize, pressurize voltage stabilizing, intensification constant temperature is one, overcomes that existing supercritical fluid SCF extraction equipment is used for laser Q-switching experiment energy consumption height, volume is big, the precision of voltage regulation is low, pump chamber is poorly sealed and influences the stable shortcoming of fluid property.

A kind of pulse laser of the present invention transfers Q with closely facing the outer fluid generator, partly constitute by build-up pressure part and circulation constant temperature bath, build-up pressure partly comprises high-pressure pump, accumulator and vacuum pump, high-pressure pump connects the air bag external space of accumulator by pipeline, the air bag of accumulator is communicated with two pipelines: wherein one be used to be communicated with hold steel cylinder that optical fluid is arranged, another is used to be communicated with the laser Q-switching optical cell, vacuum pump is used for the laser Q-switching optical cell is vacuumized by pipeline connection laser Q-switching optical cell; The circulation constant temperature bath partly comprises thermostatic bath and the circulating pump that connects by pipeline, and the circulating pump other end is used for by pipeline connection laser Q-switching optical cell, and thermostatic bath connects the constant temperature return duct, the latter is used to be communicated with the laser Q-switching optical cell; The build-up pressure part can closely be faced external pressure with transferring Q to bring up to the pressure of optical fluid; Circulation constant temperature bath part can closely be faced outer temperature with transferring Q to bring up to the temperature of optical fluid.

The described outer fluid generator that closely faces, air bag is used for the filling fluid in the accumulator, constitutes in " flexible cylinder ", under the effect repeatedly of high-pressure pump, air bag can constantly extrude the capsule inner fluid and suck new fluid, up to the fluid pressure in the optical cell is brought up to desired closely face outside state.

The described outer fluid generator that closely faces, it is further characterized in that described high-pressure pump, accumulator, vacuum pump are separately and all be equiped with break valve between the pipeline; Install unidirectional valve between vacuum pump and the break valve, prevent that fluid from flowing back in the pipeline; Also install unidirectional valve between accumulator and the break valve, prevent the fluid accumulator that flows backwards back.

The described outer fluid generator that closely faces, accumulator, vacuum pump are communicated with on the pipeline of laser Q-switching optical cell can be equiped with vent stop valve, when pressure is higher than desirable value, by vent stop valve emptying or flow to basin and regulate.

In the present invention, the air bag of accumulator becomes " flexible cylinder ", by break valve control, it

Both optical fluid can be sucked, optical fluid can be extruded again.And " flexible partition " of air bag effect can completely cut off the hydraulic fluid of optical fluid and high-pressure pump and come, and avoids impurity to scurry into optical fluid." flexible cylinder " is the core of present technique, and conventional purposes of this and accumulator (gases at high pressure energy storage and to hydraulic system supplementary pressure liquid) and routine operation method are distinct.

Circulation constant temperature bath keys available is set supercritical temperature, and after the affirmation, constant temperature bath just can be worked automatically.The design temperature of circulation constant temperature bath must not surpass the boiling point of constant temperature bath liquid under normal pressure, also must not surpass the maximum operating temperature of accumulator air bag.

This generator architecture compactness, consuming little energy, constant temperature and pressure precision height.Use this generator, can set in real time or change and closely face the outer fluid state in the optical cell.

Description of drawings

Fig. 1 SCFNCP generator architecture of the present invention schematic diagram;

Fig. 2 utilizes SCFNCP generator operation principle schematic diagram.

Embodiment

Below in conjunction with the description of drawings embodiments of the present invention.

As shown in Figure 1, the present invention closely faces the outer fluid generator and partly is made of build-up pressure part and circulation constant temperature bath, build-up pressure partly comprises break valve V2, V3, V4, the V7 on accumulator 3, high-pressure pump 4, vacuum pump 10, the pipeline, vent stop valve V5, unidirectional valve V8 and V9 also have cylinder joint 11, high-pressure pump liquid injection port 12, high-pressure pump discharging tube 13, optical cell joint 19, blow-down pipe 20, vacuum pump blast pipe 21, energy storage pressure table PI and vacuum pump pressure table PI; The circulation constant temperature bath partly comprises thermostatic bath 5, circulating pump 6, thermostatic bath discharging tube 14, constant temperature bath pressure connection 15, constant temperature bath reflux tube joint 16, constant temperature measurement and control instrument 17, thermostatic bath liquid injection port 18; Two parts are all packed in the casing 22.

Fluid in the laser Q-switching optical cell can abbreviate optical fluid as, as carbon dioxide, sulphur hexafluoride etc.As shown in Figure 2, vacuum pump 10 is used for optical cell 7 is vacuumized, and steel cylinder 1 charges into optical fluid by the air bag in the accumulator 32 in optical cell 7.The course of work is summarized as follows: close break valve V7, V3, open break valve V2, steel cylinder 1 inner fluid enters air bag 2; Close break valve V2, open break valve V7, V3, high-pressure pump 4 is pressed into optical cell 7 with the optical fluid in the air bag 2.Repeatedly carry out this process, value outside the optical cell internal pressure reaches closely facing of setting.Thermostatic bath 5 is by the constant temperature jacket 9 and the circulating pump 6 of pipeline connection optical cell 7, and circulating pump 6 is by pipeline connection constant temperature jacket 9; Circulation constant temperature bath part can closely be faced outer value with transferring Q to bring up to the temperature of optical fluid; Light 8 will be by optical cell 7 during laser works.TI represents thermometer among Fig. 2, and PI represents Pressure gauge; Break valve V1, V6 control steel cylinder 1 respectively and are pressed into the fluid of optical cell 7.

Unidirectional valve V8 of installing prevents that fluid from flowing back in the pipeline between vacuum pump 10 and the break valve V4.Also install a unidirectional valve V9 between accumulator 3 and the break valve V3, prevent the fluid accumulator that flows backwards back.If optical fluid is relatively more cheap and harmless to human and environment, then when optical cell pressure is higher than set point, can regulate it rapidly by vent stop valve V5 emptying.If optical fluid is costliness or harmful to going into environment relatively, then can when optical cell pressure is higher than set point, can allows it flow to basin by vent stop valve V5 control and regulate it at basin of vent stop valve V5 back tipping.

Casing sealing adopts the static seal of common form.

After closely facing the outer fluid generator and having assembled, the effective plug of external interface is sealed,, the pressure-bearing pipeline is carried out the hydraulic test by 1.25 times of maximum working pressure according to the hydraulic test of pressure vessel national standard.And constant temperature and pressure pipe and return duct are carried out the hydraulic test by 1.25 times of thermostatted water circulating pressure.It is then qualified that all sealings place all do not have leakage.

Before closely facing the outer fluid Laser Experiments, steel cylinder, optical cell, constant temperature circulation line etc. are connected, closely face 1.25 times of outer fluid pressure set points during by Laser Experiments the pressure-bearing pipeline is carried out the hydraulic test.And constant temperature and pressure pipe and return duct are carried out the hydraulic test by 1.25 times of thermostatted water circulating pressure.If all sealings place all do not have leakage, begin closely to face the outer fluid Laser Experiments.

Claims

1. a pulse laser transfers Q with closely facing the outer fluid generator, partly constitute by build-up pressure part and circulation constant temperature bath, build-up pressure partly comprises high-pressure pump, accumulator and vacuum pump, high-pressure pump connects the air bag external space of accumulator by pipeline, the air bag of accumulator is communicated with two pipelines: wherein one is used to be communicated with and holds the steel cylinder that optical fluid is arranged, another is used to be communicated with the laser Q-switching optical cell, and vacuum pump is used for the laser Q-switching optical cell is vacuumized by pipeline connection laser Q-switching optical cell; The circulation constant temperature bath partly comprises thermostatic bath and the circulating pump that connects by pipeline, and the circulating pump other end is used for by pipeline connection laser Q-switching optical cell, and thermostatic bath connects the constant temperature return duct, and the constant temperature return duct is used to be communicated with the laser Q-switching optical cell; Build-up pressure part will transfer Q to bring up to the pressure of optical fluid closely to face external pressure; Circulation constant temperature bath part will transfer Q to bring up to the temperature of optical fluid closely to face outer temperature.

2. the outer fluid generator that closely faces as claimed in claim 1, it is characterized in that air bag is used for the filling fluid in the accumulator, constitute in " flexible cylinder ", under the effect repeatedly of high-pressure pump, air bag constantly extrudes the capsule inner fluid and sucks new fluid, up to the fluid pressure in the optical cell is brought up to desired closely face outside state.

3. the outer fluid generator that closely faces as claimed in claim 1 or 2 is characterized in that described high-pressure pump, accumulator, vacuum pump are separately and all be equiped with break valve between the pipeline; Install unidirectional valve between vacuum pump and the break valve, prevent that fluid from flowing back in the pipeline; Also install unidirectional valve between accumulator and the break valve, prevent the fluid accumulator that flows backwards back.

4. the outer fluid generator that closely faces as claimed in claim 3 is characterized in that accumulator, vacuum pump are communicated with on the pipeline of laser Q-switching optical cell to be equiped with vent stop valve, when pressure is higher than desirable value, by vent stop valve emptying or flow to basin and regulate.