CN101871093B - Method for preparing selective absorbing coating for steel core of solar collection tube - Google Patents

Abstract

The invention provides a method for preparing a selective absorbing coating for a steel core of a solar collection tube, belonging to the field of solar energy application. The method designs optimum technology of the solar selective absorbing coating and film preparation based on analog theory operation, has the advantages of simple process, convenient operation, reliable product quality, and is suitable for large-scale industrial production. The coating preparation method improves the performance of the solar selective absorbing coating on the solar collection tube, ensures that the working temperature of the coating exceeds 400 DEG C, and can improve the solar photothermal conversion efficiency.

Description

Method for preparing selective absorbing coating for steel core of solar collection tube

Technical field

The present invention relates to a kind of method for preparing selective absorbing coating for steel core of solar collection tube, belong to the Application of Solar Energy field.

Background technology

The trough type solar power generation system be by the groove type paraboloid condensor with solar light focusing on a line, tubulose heat absorption device (thermal-collecting tube) is installed on this focal line, be used for the solar radiant energy after absorb focusing on.After fluid in the pipe was converted the solar heating of coming, the interchanger heating working medium of flowing through was converted to the hot steam of High Temperature High Pressure, relended to help steam circulation power and generate electricity.The trough type solar power generation technology is ripe relatively, so applied widely in the world, this class power station is distributed in the abundant country of solar energy resourceses such as Algeria, Australia, Egypt, India, Iran, Italy, Morocco, Mexico, Spain, the U.S..The high-temperature vacuum pipe receivers is the core component of total system in this system, is provided by Israel Solel company (predecessor is a LUZ company).Germany Schott company has done improvement to high-temperature vacuum pipe: the one, for preventing the too high sealing-in quality that influences of two ends temperature, increased solar radiation reflection circle in the part; The 2nd, make every effort to reduce the shading area to greatest extent, make valve tube effectively utilize length greater than 96%; The 3rd, adjust relevant glass material prescription, kovar alloy and Glass tubing sealing-in are got better.Focus in the generating at groove type paraboloid, the performance that improves solar selectively absorbing coating on the thermal-collecting tube surpasses 400 ℃ with the working temperature that improves coating and can improve the efficient that solar energy converting becomes heat energy.

Summary of the invention

The invention provides a kind of method for preparing selective absorbing coating for steel core of solar collection tube.This coating production should improve the performance of solar selectively absorbing coating on the thermal-collecting tube and surpass 400 ℃ in the working temperature of coating and can improve the solar energy thermal conversion efficiency.

The technical solution adopted in the present invention is: a kind of method for preparing selective absorbing coating for steel core of solar collection tube, this preparation method adopts the d.c. sputtering metal targets, the method of radio-frequency sputtering oxide target material and reaction cosputtering prepares the reflective metal layer of selective coating, absorption layer and antireflection layer; The equipment that uses mainly comprises vacuum system, planar magnetic control sputtering, column-shape magnetron sputtering, grid bias power supply heating system, airing system and water-cooling system, stainless steel tube is installed on the revolution rotation work rest in the water-cooled vacuum chamber, and preparation X-Y film is that preparation process is on stainless steel tube:

One, design film layer structure

1, at first prepare individual layer X film and Y film, measure specific refraction n and optical extinction coefficient k,

2, respectively the X film with different components and the optical parametric of Y film are calculated,

3, carry out modeling with TFC film design software, simulate the structure of optimization solar selectively absorbing coating,

4, with the inverting of theoretical modeling calculation result on preparation technology.Utilize film thickness gauge accurately to detect regulation and control and adjust preparation X film/highly doped X-Y film/low-doped X-Y film/pure Y film,

5, utilize Lambda 950 spectrophotometers, test set measurement of reflectivity such as infrared emittance detector, transmissivity, multilayer film optical parametrics such as emittance,

6, theoretical and result confirms contrast mutually, obtains preparing the optimised process of satisfactory rete;

Two, preparation X-Y film is a technological process:

1, vacuum chamber pumping process:

(1) threshold switch of fetching boiling water.And check whether each pipeline water flowing is smooth and easy,

(2) open mechanical pump,

(3) open and take out valve in advance, bleeding is evacuated to 500Pa, opens lobe pump, is evacuated to 5Pa again, in the process of bleeding with the power supply opening of molecular pump 4～5 minutes,

(4) close and take out valve in advance, step valve left high valve after 1 minute before opening, and opened the molecular pump pumping high vacuum, up to pressure to processing requirement,

2, according to working specification, pivoted frame is opened in heating,

3, according to technological process, send Ar gas,

4, use the plasma clean stainless steel tube,

5, adopt planar magnetic control sputtering X target sputtering sedimentation, preparation X reflecting layer,

6, adopt rf magnetron sputtering Y sputtering sedimentation Y and planar magnetic control sputtering X target sputtering sedimentation X, while formation of deposits absorption layer, ratio and the deposition of X and Y depend on sputtering power,

7, adopt rf magnetron sputtering sputtering sedimentation Y film separately, deposition depends on sputtering power.

X in the described X-Y film system is W, Mo or Al metal, and Y is SiO ₂, Al ₂O ₃Or AlN pottery.

Above-mentioned theoretical basis about X film and Y membrane simulation calculating is: equivalent medium theory is thought, when a kind of particles of material evenly is embedded in the matrix material that constitutes the macrostructure uniformity in the another kind of body material, the dielectric properties of material can be come equivalence with a kind of dielectric properties of homogeneous material, and the specific inductivity of this material is exactly the effective dielectric constant of the heterogeneous material studied.The MG theory in 1904 with you can well imagine out 1906 the fraction of the year, originates in the Clausius-Mossotti formula by Maxwell and Garnett, is applicable to be embedded into spherical metal particulate sintering metal system in the dielectric matrix and to have done following supposition:

(1) metal particle of minute quantity is scattered in the dielectric matrix, and the distance between the particulate is bigger, does not interact each self-scattering between the particulate;

(2) particulate is by the transient field induced polarization;

(3) outfield can be revised with the Lorentz local fields

If the specific inductivity of medium is ε 1, metal ball shaped particulate specific inductivity is ε 2, and then the DIELECTRIC CONSTANT of two-phase compound system can be formulated:

$\mathrm{\ϵMG}=\mathrm{\ϵ}1\frac{\mathrm{\ϵ}2+2\mathrm{\ϵ}1+2f\left(\mathrm{\ϵ}2-\mathrm{\ϵ}1\right)}{\mathrm{\ϵ}2+2\mathrm{\ϵ}1-f(\mathrm{\ϵ}2-\mathrm{\ϵ}1)}$

F is the metal volume mark in the formula.

The available formula 3-2 of relation in the optical frequency scope between the complex refractivity index N of compound system and the equivalent complex permittivity ε represents:

$N=n+\mathrm{ik}=\sqrt{\mathrm{\ϵ}}$

N in the formula, k are respectively the light refractive index and the optical extinction coefficient of compound system

The invention has the beneficial effects as follows: this method for preparing selective absorbing coating for steel core of solar collection tube is owing to obtain preparing the optimised process of satisfactory rete on the basis that modeling theory is calculated, this technology is simple, easy to operate, reliable product quality is fit to the big rule curtain of tissue industrial production.This coating production has improved the performance of solar selectively absorbing coating on the thermal-collecting tube and has surpassed 400 ℃ with working temperature in coating and can improve the efficient that solar energy converting becomes electric energy, reduces its cost of electricity-generating.

Description of drawings

Fig. 1 is a kind of selective absorbing coating for steel core of solar collection tube equipment front view.

Fig. 2 is a kind of selective absorbing coating for steel core of solar collection tube equipment vertical view.

Fig. 3 is vacuum chamber structure figure.

Among the figure: 1, water-cooled vacuum chamber, 2, revolution rotation work rest, 3, the insulation of carriage transmission shaft, 4, the plated film stainless steel tube, 5, well heater, 6, the column-shape magnetron sputtering target, 7, transmission shaft, 8, the pivoted frame power motor, 9,10, the metal controlled sputtering source, 11,12, the rf magnetron sputtering target, 13, door for vacuum chamber, 14, temperature thermocouple, 15, the thickness tester, 16, high valve, 17, molecular pump, 18, preceding step valve, 19, take out valve in advance, 20, by-pass valve, 21, lobe pump, 22, mechanical pump.

Embodiment

Fig. 1,2,3 shows a kind of selective absorbing coating for steel core of solar collection tube equipment drawing.This metal-ceramic coating equipment mainly comprises a vacuum chamber and a vacuum system, vacuum chamber and vacuum system by pipe connection together, plated film stainless steel tube 4 is installed in the pivoted frame mechanism that is driven by external motor in the vacuum chamber; It also comprises metal controlled sputtering source 9,10 and the rf magnetron sputtering target 11,12 that is installed on the vacuum chamber; Be provided with well heater 5, column-shape magnetron sputtering target 6, temperature thermocouple 14, thickness tester 15 in the vacuum chamber; Vacuum system is connected with vacuum chamber through a high valve 16, the outlet of high valve 16 is provided with and takes out valve 19 in advance, the outlet one tunnel of taking out valve 19 in advance connects mechanical pump 22 and lobe pump 21 through by-pass valve 20, another Lu Jingqian step valve 18 link molecule pumps 17, and the outlet of taking out valve 19 in advance also directly connects lobe pump 21.

The pivoted frame mechanism that water-cooled vacuum chamber 1 adopts is positioned at the bottom of vacuum chamber, and pivoted frame power motor 8 is positioned at the outside of vacuum chamber, and a side of vacuum chamber is provided with a door for vacuum chamber 13.This equipment can conveniently prepare various metallic films or ceramic membrane etc.

Embodiment 1: the metallic film preparation method

1, vacuumize according to working specification, pivoted frame is opened in heating;

2,, send Ar gas according to technological process;

3, plasma clean workpiece;

4, the planar magnetic control sputtering metallic target prepares film, opens baffle plate, can adopt two direct supplys or intermediate frequency power supply to prepare metallic film (the composition metal alloy firm in like manner) separately;

5, column-shape magnetron sputtering target adopts direct supply, the preparation metallic film;

6, preparation metallic film or preparation composition metal alloy firm can adopt intermediate frequency power supply sputter planar metal target and direct supply sputter cylindrical metal target to unite use, and deposition is by vacuum gas pressure and sputtering current control.

Embodiment 2: the ceramic membrane preparation method

Adopt ceramic target radio-frequency sputtering deposition or planar magnetic control sputtering method for reactive sputter deposition to prepare ceramic membrane.

Embodiment 3:SiO2 method for manufacturing thin film

1, vacuumize according to working specification, pivoted frame is opened in heating;

2,, send Ar gas according to technological process;

3, plasma clean workpiece;

4, adopt rf magnetron sputtering (SiO2) target, open baffle plate, the radio-frequency plasma sputtering sedimentation.Deposition mainly depends on radio frequency power.

Embodiment 4:Al-N method for manufacturing thin film

1, vacuumize according to working specification, pivoted frame is opened in heating;

2,, send Ar gas according to technological process;

3, plasma clean workpiece;

4, by column-shape magnetron sputtering aluminium target, adopt direct supply sputter reactive deposition or intermediate frequency power supply sputter reactive deposition technology, reactant gases is made up of Ar and N2 gas mixture, and film forming phase composition and weave construction depend on gas ratio and sputtering voltage-electric current.

Embodiment 5:Mo-SiO2 method for manufacturing thin film

1, vacuumize according to working specification, pivoted frame is opened in heating;

2,, send Ar gas according to technological process;

3, plasma clean workpiece;

4, adopt planar magnetic control sputtering Mo target sputtering sedimentation metal M o, preparation metallic reflector;

5, adopt rf magnetron sputtering (silicon oxide target) sputtering sedimentation SiO ₂With planar magnetic control sputtering Mo target sputtering sedimentation metal M o while formation of deposits absorption layer, metal and SiO ₂Ratio and deposition depend on sputtering power;

6, adopt rf magnetron sputtering sputtering sedimentation SiO separately ₂Film, deposition depends on sputtering power.

Embodiment 6:Mo-AlN method for manufacturing thin film

1, vacuumize according to working specification, pivoted frame is opened in heating;

2,, send Ar gas according to technological process;

3, plasma clean workpiece;

4, adopt planar magnetic control sputtering Mo target sputtering sedimentation metal M o, preparation metallic reflector;

5, feed Ar and N2 mixed gas, adopt column-shape magnetron sputtering (Al target) sputtering sedimentation AlN and

Planar magnetic control sputtering Mo target sputtering sedimentation metal M o codeposition forms absorption layer, and the ratio of metal and AlN and deposition depend on sputtering power and gas ratio;

6, adopt column-shape magnetron sputtering target sputtering sedimentation AlN anti-reflection film separately, phase structure and composition depend on gas ratio and sputtering power.

Claims (2)

1. method for preparing selective absorbing coating for steel core of solar collection tube, this preparation method adopts the d.c. sputtering metal targets, and the method for radio-frequency sputtering oxide target material and reaction cosputtering prepares the reflective metal layer of selective coating, absorption layer and antireflection layer; The equipment that uses mainly comprises vacuum system, planar magnetic control sputtering, column-shape magnetron sputtering, grid bias power supply heating system, airing system and water-cooling system, stainless steel tube (4) is installed on the revolution rotation work rest (2) in the water-cooled vacuum chamber (1), goes up preparation X-Y film system at stainless steel tube (4); It is characterized in that: described X-Y film is that preparation process is:

One, design film layer structure

1, at first prepare individual layer X film and Y film, measure specific refraction n and optical extinction coefficient k,

2, respectively the X film with different components and the optical parametric of Y film are calculated,

3, carry out modeling with TFC film design software, simulate the structure of optimization solar selectively absorbing coating,

4, with the inverting of theoretical modeling calculation result on preparation technology, utilize film thickness gauge accurately to detect regulation and control and adjust preparation X film/highly doped X-Y film/low-doped X-Y film/pure Y film,

5, utilize spectrophotometer, infrared emittance detector test set measurement of reflectivity, transmissivity, emittance multilayer film optical parametric,

6, theoretical and result confirms contrast mutually, obtains preparing the optimised process of satisfactory rete;

Two, preparation X-Y film is a technological process:

1, vacuum chamber pumping process:

(1) threshold switch of fetching boiling water, and check whether each pipeline water flowing is smooth and easy,

(2) open mechanical pump (22),

(3) open and take out valve (19) in advance, bleeding is evacuated to 500Pa, opens lobe pump (21), is evacuated to 5Pa again, in the process of bleeding with the power supply opening of molecular pump (17) 4～5 minutes,

(4) close and take out valve (19) in advance, open preceding step valve after (18) 1 minutes, drive high valve (16), open molecular pump (17) pumping high vacuum, up to pressure to processing requirement,

2, according to working specification, pivoted frame is opened in heating,

3, according to technological process, send Ar gas,

4, with plasma clean stainless steel tube (4),

5, adopt planar magnetic control sputtering X target sputtering sedimentation, preparation X reflecting layer,

6, adopt rf magnetron sputtering Y sputtering sedimentation Y and planar magnetic control sputtering X target sputtering sedimentation X, while formation of deposits absorption layer, ratio and the deposition of X and Y depend on sputtering power,

7, adopt rf magnetron sputtering sputtering sedimentation Y film separately, deposition depends on sputtering power.

2. according to the described method for preparing selective absorbing coating for steel core of solar collection tube of claim 1, it is characterized in that: the X in the described X-Y film system is W, Mo or Al metal, and Y is SiO ₂, Al ₂O ₃Or AlN pottery.

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