CN104931151A - Non-contact type measuring device used for measuring mirror surface temperature of large-diameter solar telescope primary mirror - Google Patents

Abstract

The invention provides a non-contact type measuring device used for measuring mirror surface temperature of a large-diameter solar telescope primary mirror. The non-contact type measuring device mainly comprises a primary mirror panel (1), an air lance (2), an ambient temperature sensor (3), an air jet temperature sensor (4), a total radiation sensor (5), an anemometer (6) and a data processing module (7). During the operating process of a solar telescope, the mirror surface temperature rise of the primary mirror can cause mirror surface seeing effect and mirror surface thermal deformation, and the performance of the solar telescope is severely restricted. The non-contact type measuring device can be used for monitoring mirror surface temperature of the primary mirror in real time, provides important basis for mirror surface temperature control of the solar telescope primary mirror, and provides data for the analysis of the mirror surface seeing effect and mirror surface thermal deformation. When compared with the traditional contact type temperature measuring device, the non-contact type measuring device can effectively avoid damages to a mirror surface coating by the traditional device and measurement errors caused by exposing the temperature sensor in solar radiation; in addition, the non-contact type measuring device is simple in structure, convenient in operation and low in cost, and has high practicality and innovativeness.

Description

A kind of non-contact measurement apparatus measured for heavy caliber helioscope primary mirror mirror temperature

Technical field

The present invention relates to helioscope domain of control temperature, particularly for a kind of non-contact measurement apparatus measured for heavy caliber helioscope primary mirror mirror temperature.

Background technology

Along with the development of modern sun physics research, require to improve constantly to the space needed for the activity observation of sun surface, time and spectral resolution, and impel the bore of helioscope constantly to increase.At present, solar physics research has been deep into the high resolution observation to sun surface fine structure, and require to reach 50-70km to the spatial resolution on sun surface, this just requires that the bore of corresponding helioscope must reach 1m or larger.

Due to heavy caliber envelope window manufacture difficulty and piezobirefringence effect, traditional vacuum type lens barrel be progressively applied to the open lens barrel of heavy caliber helioscope substitute.But, open lens barrel makes primary mirror minute surface directly be exposed in air, except the Mirror thermal distortion that minute surface temperature rise causes, minute surface temperature rise also will cause minute surface seeing effect (Mirror Seeing Effect) and worsen telescope imaging picture element further.In order to reduce Mirror thermal distortion and minute surface seeing effect to the adverse effect of telescope performance, at present, each heavy caliber helioscope in world wide, as DKIST, EST, GREGOR, NST, CLST and GREGOR, has all installed active temperature control system to primary mirror.No matter for thin primary mirror or lightweight primary mirror, primary mirror temperature control system, all by being arranged on the air jet arrays of minute surface lower panels, utilizes the air-spray of specified temp to carry out ACTIVE CONTROL to mirror temperature.

But, because the high-reflectivity metal film of primary mirror minute surface very easily damages, and be directly exposed to temperature sensor under the direct irradiation of the sun due to passive heating and be difficult to accurate thermometric.Therefore, in helioscope practical work process, mirror temperature cannot carry out temperature Real-Time Monitoring by the contact measurement method that sticking temperature sensor is traditional.At present, part telescope adopts in primary mirror edge or supporting construction shade, i.e. territory, non-transparent zone, the mode of pasting SMD temperature sensor is directly measured mirror temperature.But the method not only cannot reflect the temperature of minute surface regional all sidedly, the plated film of sticking area more may be caused to damage the plated film affecting territory, periphery transparent zone even further.Therefore, a kind of non-contact type temperature measurement method can carrying out Measurement accuracy to helioscope mirror temperature is badly in need of.

Based on above background, the present invention proposes a kind of non-contact measurement apparatus measured for heavy caliber helioscope primary mirror mirror temperature.Helioscope is reduced to the flat late heat transfer model under air-spray cooling by the present invention with the primary mirror of active cooling device, set up the quantitative relationship of mirror body each point temperature and mirror body surrounding air parameter, achieve the indirect inspection by reaching the measurement of mirror body surrounding air parameter mirror body each point temperature, particularly mirror temperature.In addition, this apparatus structure is simple, easy to operate, with low cost, has stronger practicality and novelty.

Summary of the invention

The technical problem to be solved in the present invention is: under the prerequisite that each sensor does not directly contact primary mirror mirror body, particularly primary mirror minute surface, by going out the temperature of primary mirror mirror body, particularly minute surface to the real-time measurement indirect inspection of mirror body surrounding air parameter.

The technical scheme that the present invention solves the problems of the technologies described above employing is: a kind of non-contact measurement apparatus measured for heavy caliber helioscope primary mirror mirror temperature, by primary mirror panel, air lance, environment temperature sensor, air-spray temperature sensor, built-up radiation sensor, anemoscope and data processing module seven part composition.

Wherein, environment temperature sensor is arranged near primary mirror, for monitoring of environmental temperature; Air-spray temperature sensor is arranged on air lance outlet, for monitoring air-spray temperature; Built-up radiation sensor is arranged in telescope frame, and just to the sun, for detecting solar irradiance; Anemoscope is arranged near primary mirror, for detecting telescope periphery wind speed; Data processing module is connected with above-mentioned all the sensors, for the record to above-mentioned all the sensors real time data, process and display.

The data handling procedure of this device is as described below:

Environmental parameter defines: the environment temperature that environment temperature sensor recorded in the i-th moment is (unit: DEG C); The air-spray temperature that air-spray temperature sensor recorded in the i-th moment is (unit: DEG C); Built-up radiation sensor is q in the solar irradiance that the i-th moment recorded ⁱ(unit: W/m ²), the flow rate of ambient air that anemoscope recorded in the i-th moment is (unit: m/s).

Primary mirror board parameter defines: panel material heat-conduction coefficient, specific heat capacity and density are respectively: k (unit: W/m DEG C), C _p(unit: J/Kg DEG C), ρ (unit: Kg/m ³).Primary mirror thickness L _thickness(unit: m), spatial domain step-length (N is that spatial discretization is counted), time domain step-length △ t (unit: s).

Surrounding air parameter defines: primary mirror diameter L (unit: m), environmental aerodynamics coefficient of viscosity ν ₁(table look-up, unit: m ²s), surrounding air heat-conduction coefficient λ ₁(tabling look-up, unit: W/m DEG C), surrounding air Prandtl number Pr ₁(tabling look-up, dimensionless number).

Jet air parameter defines: air lance internal diameter D (unit: m), nozzle exit and minute surface panel spacing H (unit: m), fluerics radius r (unit: m), air-spray dynamics coefficient of viscosity ν ₂(table look-up, position: m ²s), air-spray heat-conduction coefficient λ ₂(tabling look-up, unit: W/m DEG C), air-spray Prandtl number Pr ₂(tabling look-up, dimensionless number).

Then, heat conduction parameters is calculated.

Primary mirror minute surface convective heat-transfer coefficient h _ncalculate:

${\mathrm{Re}}_L^i=\frac{u_L^{i}L}{{\mathrm{\ν}}_1}---\left(1\right)$

Work as Re _l≤ 5 × 10 ⁵time, use equation (2); Work as Re _l>5 × 10 ⁵time, use equation (3).

$h_n=0.664{\left({\mathrm{Re}}_L^i\right)}^{1/2}{\mathrm{Pr}}_1^{1/3}\frac{{\mathrm{\λ}}_1}{L}---\left(2\right)$

$h_n=0.037\[{\left({\mathrm{Re}}_L^i\right)}^{4/5}-871\]{\mathrm{Pr}}_1^{1/3}\frac{{\mathrm{\λ}}_1}{L}---\left(3\right)$

Primary mirror backboard side convective heat-transfer coefficient h _ccalculate:

$h_c=2{\left(\frac{u_{D}D}{v_2}\right)}^{0.5}{{\mathrm{Pr}}_2}^{0.42}{(1+0.005{\left(\frac{u_{D}D}{v_2}\right)}^{0.5})}^{0.5}\frac{{\mathrm{\λ}}_2}{D}\frac{1-1.1D/r}{1+0.1(H/D-6)D/r}\frac{D}{r}---\left(4\right)$

Finally, above-mentioned parameter is substituted into recursion formula:

Wherein, $A=\mathrm{\τ}=\frac{k\mathrm{\Δ}t}{{\mathrm{\ρC}}_p{\mathrm{\Δx}}^2},B=-(1+2\mathrm{\τ}),C=-(1+2\mathrm{\τ}+2\mathrm{\τ}\frac{\mathrm{\Δ}x\·h_C}{k}),D=2\mathrm{\τ}\frac{\mathrm{\Δ}x\·h_C}{k},$ $E=-(1+2\mathrm{\τ}+2\mathrm{\τ}\frac{\mathrm{\Δ}x\·h_n}{k}),F=2\mathrm{\τ}\frac{\mathrm{\Δ}x\·h_n}{k},G=2\mathrm{\τ}\frac{\mathrm{\Δ}x}{k},\mathrm{\τ}=\frac{k}{{\mathrm{\ρC}}_p}\×\mathrm{\Δ}t/{\mathrm{\Δx}}^2,\mathrm{\Δ}x=\frac{L_{thickness}}{N}.$

Through one night constant temperature, think telescope body temperature identical with environment temperature (as starting condition) everywhere, by recursion formula (5), each moment primary mirror mirror temperature can be tried to achieve

Principle of the present invention:

No matter adopt thin primary mirror or the lightweight primary mirror of Active Cooling, all can be reduced to the flat late heat transfer model under air-spray cooling, as shown in Figure 2, wherein a-1 is primary mirror minute surface, and a-2 is primary mirror backboard side, and a-3 is air lance.Be primary mirror panel one dimensional transient heat transfer model further by model conversation, as shown in Figure 3.

According to associated heat transfer theory, above-mentioned one dimensional transient heat transfer model and up-and-down boundary condition thereof can represent by following differential equation group:

$\left\{\begin{array}{c}k\frac{{\∂}^{2}T(x,t)}{\∂x^2}={\mathrm{\ρC}}_p\×\frac{\∂T(x,t)}{\∂t}\left(t>0,0\≤x\≤L\right)\\ -k\×\frac{\∂T(0,t)}{\∂x}=h_c\×(T(0,t)-T_c\left(t\right))\\ -k\×\frac{\∂T(N,t)}{\∂x}=h_n\×T((N,t)-T_{amb}\left(t\right))+q\left(t\right)\end{array}\right.---\left(6\right)$

Wherein, k, ρ and C _pbe respectively primary mirror plate material heat-conduction coefficient, density and specific heat capacity; T _c(t), T _ambt () and q (t) are respectively air lance (a-2) outlet air temperature, the time dependent function of solar irradiance that environment temperature and minute surface absorb; h _nand h _cbe respectively the air heat-conduction coefficient of primary mirror minute surface (a-1) and primary mirror backboard side (a-3).T (x, t) is for t is at the mirror temperature of x position.

Wherein, h _nand h _ccan solve with Correlation respectively, as shown in equation (1)-(4).

Solve differential equation group (6), adopt center and forward difference to the second-order differential item of position and temperature to the first differential item of time to temperature respectively, corresponding DIFFERENCE EQUATIONS is as shown in system of equations (7).

$\left\{\begin{array}{c}k\left(\frac{T_{m-1}^{i+1}-2T_m^{i+1}+T_{m+1}^{i+1}}{{\mathrm{\Δx}}^2}\right)={\mathrm{\ρC}}_p\frac{\left(T_m^{i+1}-T_m^i\right)}{\mathrm{\Δ}t}\\ k\frac{\left(T_1^{i+1}-T_0^{i+1}\right)}{\mathrm{\Δ}x}+h_c(T_c^{i+1}-T_0^{i+1})={\mathrm{\ρC}}_p\frac{\mathrm{\Δ}x}{2}\frac{\left(T_0^{i+1}-T_0^i\right)}{\mathrm{\Δ}t}\\ k\frac{\left(T_N^{i+1}-T_{N-1}^{i+1}\right)}{\mathrm{\Δ}x}+h_n(T_{amb}^{i+1}-T_N^{i+1})+q={\mathrm{\ρC}}_p\frac{\mathrm{\Δ}x}{2}\frac{\left(T_N^{i+1}-T_N^i\right)}{\mathrm{\Δ}t}\end{array}\right.---\left(7\right)$

Continue solving equation group (7), finally obtain system of equations (5), be i.e. the recursion formula of minute surface temperature and surrounding air parameter everywhere.

The present invention compared with prior art has the following advantages:

(1). a kind of non-contact measurement apparatus measured for heavy caliber helioscope primary mirror mirror temperature that the present invention proposes, achieve under the prerequisite not contacting primary mirror mirror body, by to primary mirror mirror body ambient air temperature, achieve between the measurement of solar irradiance and air velocity mirror body temperature everywhere, the particularly indirect inspection of primary mirror mirror temperature value.Compared to conventional contact measurement mechanism, this device without the need to primary mirror mirror body, particularly primary mirror minute surface directly contacts, and avoids the damage that contact type measurement is possible to mirror metal film system.

(2). a kind of non-contact measurement apparatus measured for heavy caliber helioscope primary mirror mirror temperature that the present invention proposes, achieve primary mirror mirror temperature, the particularly non-contact measurement of mirror temperature, effectively prevent SMD temperature sensor in conventional contact measurement mechanism to be directly exposed under minute surface solar radiation and to be heated, and finally cause the situation of larger measuring error.

(3). a kind of non-contact measurement apparatus measured for heavy caliber helioscope primary mirror mirror temperature that the present invention proposes, required only several various kinds of sensors, volume is little, easy for installation, with low cost, easy to operate, there is stronger practicality and novelty.

In a word, a kind of non-contact measurement apparatus measured for heavy caliber helioscope primary mirror mirror temperature relying on the present invention to propose, non-contacting mode can be adopted helioscope primary mirror mirror body temperature everywhere, the particularly temperature of primary mirror minute surface, effectively measure, and avoid the various adverse effects that conventional contact temperature measuring equipment brings simultaneously.Meanwhile, this device has low cost, and structure is simple, is easy to the features such as realization, has stronger practicality and novelty.

Accompanying drawing explanation

Fig. 1 is a kind of non-contact measurement apparatus measured for heavy caliber helioscope primary mirror mirror temperature.Wherein, 1 is primary mirror panel, and 2 is air lance, and 3 is environment temperature sensor, and 4 is air-spray temperature sensor, and 5 is built-up radiation sensor, and 6 is anemoscope, and 7 is data processing module.

Fig. 2 is the flat late heat transfer model under air-spray cooling.Wherein, a-1 is primary mirror minute surface, and a-2 is primary mirror backboard side, and a-3 is air lance.

Fig. 3 is primary mirror panel one dimensional transient heat transfer model.Wherein, T _c, T _ambair lance (a-2) outlet air temperature is respectively, the time dependent function of solar irradiance that environment temperature and minute surface absorb with q; h _nand h _cbe respectively the air heat-conduction coefficient of primary mirror minute surface (a-1) and primary mirror backboard side (a-3); L is primary mirror plate thickness; X is primary mirror heat transfer direction; N is that spatial discretization is counted.

Fig. 4 is a kind of possible embodiment of the non-contact measurement apparatus for the measurement of heavy caliber helioscope primary mirror mirror temperature.Wherein, b-1 is refrigeration machine, and b-2 is heat exchanger, and b-3 is electric heater, b-4 is controller, and b-5 is blower fan, and b-6 is draught distributing box, and b-7 is built-up radiation sensor, b-8 is anemoscope, and b-9 is computing machine, and s1 is air-spray temperature sensor, and s2 is air temperature sensor.

Embodiment

The present invention is further illustrated below in conjunction with accompanying drawing and specific embodiment.

As shown in Figures 1 to 3, basic thought of the present invention is to provide a kind of non-contact measurement apparatus measured for heavy caliber helioscope primary mirror mirror temperature, by primary mirror panel, air lance, environment temperature sensor, air-spray temperature sensor, built-up radiation sensor, 7 module compositions such as anemoscope and data processing module.

For a possible embodiment for the non-contact measurement apparatus that heavy caliber helioscope primary mirror mirror temperature is measured, concrete, as shown in Figure 4:

Wherein, b-1 is refrigeration machine, and b-2 is heat exchanger, and b-3 is electric heater, and b-4 is controller, and b-5 is blower fan, and b-6 is draught distributing box.Above six parts together constitute light weight cellular primary mirror temperature control system.This temperature control system is divided into two-stage, and the first order forms liquid cooling by refrigeration machine b-1 and heat exchanger b-2 and circulates, and cools circulating air; The second level forms air cooling by heat exchanger b-2, electric heater b-3, blower fan b-5 and draught distributing box b-6 etc. and circulates, by the collaborative work under controller b-4 controls of heat exchanger b-2 and electric heater b-3, realize controlling the temperature of circulating air, and finally mirror temperature is controlled.

Wherein, the non-contact measurement apparatus that this primary mirror mirror temperature is measured is built-up radiation sensor by b-7, and b-8 is anemoscope, and b-9 is computing machine, and s1 is air-spray temperature sensor, and s2 is air temperature sensor five part composition.Air temperature sensor s2 is arranged near primary mirror, for monitoring of environmental temperature (unit: DEG C); Air-spray temperature sensor s1 is arranged on air lance outlet, for monitoring air-spray temperature (unit: DEG C); Built-up radiation sensor b-7 is arranged in telescope frame, and just to the sun, for monitoring solar irradiance q ⁱ(unit: W/m ²); Anemoscope b-8 is arranged near primary mirror, for monitoring telescope periphery wind speed (unit: m/s); Computing machine b-9 is connected with above-mentioned all the sensors, for the process to above-mentioned all the sensors real time data, record and display.

The data handling procedure of this device is as described below:

First, defined parameters.

Environmental parameter defines: the environment temperature that environment temperature sensor 3 recorded in the i-th moment is (unit: DEG C); The air-spray temperature that air-spray temperature sensor recorded in the i-th moment is (unit: DEG C); Built-up radiation sensor 5 is q in the solar irradiance that the i-th moment recorded ⁱ(unit: W/m ²), the flow rate of ambient air that anemoscope 6 recorded in the i-th moment is (unit: m/s).

Primary mirror board parameter defines: panel material heat-conduction coefficient, specific heat capacity and density are respectively: k (unit: W/m DEG C), C _p(unit: J/Kg DEG C), ρ (unit: Kg/m ³).Primary mirror thickness L _thickness(unit: m), spatial domain step-length (N is that spatial discretization is counted), time domain step-length △ t (unit: s).

Surrounding air parameter defines: primary mirror diameter L (unit: m), environmental aerodynamics coefficient of viscosity ν ₁(table look-up, unit: m ²s), surrounding air heat-conduction coefficient λ ₁(tabling look-up, unit: W/m DEG C), surrounding air Prandtl number Pr ₁(tabling look-up, dimensionless number).

Jet air parameter defines: air lance 2 internal diameter D (unit: m), nozzle exit and minute surface panel spacing H (unit: m), fluerics radius r (unit: m), air-spray dynamics coefficient of viscosity ν ₂(table look-up, position: m ²s), air-spray heat-conduction coefficient λ ₂(tabling look-up, unit: W/m DEG C), air-spray Prandtl number Pr ₂(tabling look-up, dimensionless number).

Then, heat conduction parameters is calculated.

Primary mirror minute surface convective heat-transfer coefficient h _ncalculate:

${\mathrm{Re}}_L^i=\frac{u_L^{i}L}{{\mathrm{\ν}}_1}---\left(1\right)$

Work as Re _l≤ 5 × 10 ⁵time, use equation (2); Work as Re _l>5 × 10 ⁵time, use equation (3).

$h_n=0.664{\left({\mathrm{Re}}_L^i\right)}^{1/2}{\mathrm{Pr}}_1^{1/3}\frac{{\mathrm{\λ}}_1}{L}---\left(2\right)$

$h_n=0.037\[{\left({\mathrm{Re}}_L^i\right)}^{4/5}-871\]{\mathrm{Pr}}_1^{1/3}\frac{{\mathrm{\λ}}_1}{L}---\left(3\right)$

Primary mirror backboard side convective heat-transfer coefficient h _ccalculate:

$h_c=2{\left(\frac{u_{D}D}{v_2}\right)}^{0.5}{{\mathrm{Pr}}_2}^{0.42}{(1+0.005{\left(\frac{u_{D}D}{v_2}\right)}^{0.5})}^{0.5}\frac{{\mathrm{\λ}}_2}{D}\frac{1-1.1D/r}{1+0.1(H/D-6)D/r}\frac{D}{r}---\left(4\right)$

Finally, above-mentioned parameter is substituted into recursion formula:

Wherein, $A=\mathrm{\τ}=\frac{k\mathrm{\Δ}t}{{\mathrm{\ρC}}_p{\mathrm{\Δx}}^2},B=-(1+2\mathrm{\τ}),C=-(1+2\mathrm{\τ}+2\mathrm{\τ}\frac{\mathrm{\Δ}x\·h_C}{k}),D=2\mathrm{\τ}\frac{\mathrm{\Δ}x\·h_C}{k},$ $E=-(1+2\mathrm{\τ}+2\mathrm{\τ}\frac{\mathrm{\Δ}x\·h_n}{k}),F=2\mathrm{\τ}\frac{\mathrm{\Δ}x\·h_n}{k},G=2\mathrm{\τ}\frac{\mathrm{\Δ}x}{k},\mathrm{\τ}=\frac{k}{{\mathrm{\ρC}}_p}\×\mathrm{\Δ}t/{\mathrm{\Δx}}^2,\mathrm{\Δ}x=\frac{L_{thickness}}{N}.$

Through one night constant temperature, think telescope body temperature identical with environment temperature (as starting condition) everywhere, by recursion formula (5), each moment primary mirror mirror temperature can be tried to achieve

The above; be only the specific embodiment of the present invention; but protection scope of the present invention is not limited thereto; any people being familiar with this technology is in disclosed technical scope; the replacement be understood that or increase and decrease; all should be encompassed in and of the present inventionly comprise within scope, therefore, protection scope of the present invention should be as the criterion with the protection domain of claims.

Claims (6)

1. the non-contact measurement apparatus measured for heavy caliber helioscope primary mirror mirror temperature, it is characterized in that: by primary mirror panel (1), air lance (2), environment temperature sensor (3), air-spray temperature sensor (4), built-up radiation sensor (5), anemoscope (6) and data processing module (7) seven part composition;

Wherein, environment temperature sensor (3) is arranged near primary mirror, for monitoring of environmental temperature; Air-spray temperature sensor (4) is arranged on air lance (2) outlet, for monitoring air-spray temperature; Built-up radiation sensor (5) is arranged in telescope frame, and just to the sun, for detecting solar irradiance; Anemoscope (6) is arranged near primary mirror, for detecting telescope periphery wind speed; Data processing module (7) is connected with above-mentioned all the sensors, for the record to above-mentioned all the sensors real time data, process and display;

The data handling procedure of this device is as described below:

First, defined parameters;

Environmental parameter defines: the environment temperature that environment temperature sensor (3) recorded in the i-th moment is (unit: DEG C); The air-spray temperature that air-spray temperature sensor recorded in the i-th moment is (unit: DEG C); Built-up radiation sensor (5) is q in the solar irradiance that the i-th moment recorded ⁱ(unit: W/m ²), the flow rate of ambient air that anemoscope (6) recorded in the i-th moment is (unit: m/s);

Primary mirror board parameter defines: panel material heat-conduction coefficient, specific heat capacity and density are respectively: k (unit: W/m DEG C), C _p(unit: J/Kg DEG C), ρ (unit: Kg/m ³), primary mirror thickness L _thickness(unit: m), spatial domain step-length (N is that spatial discretization is counted), time domain step-length △ t (unit: s);

Surrounding air parameter defines: primary mirror diameter L (unit: m), environmental aerodynamics coefficient of viscosity ν ₁(table look-up, unit: m ²s), surrounding air heat-conduction coefficient λ ₁(tabling look-up, unit: W/m DEG C), surrounding air Prandtl number Pr ₁(tabling look-up, dimensionless number);

Jet air parameter defines: air lance (2) internal diameter D (unit: m), nozzle exit and minute surface panel spacing H (unit: m), fluerics radius r (unit: m), air-spray dynamics coefficient of viscosity ν ₂(table look-up, position: m ²s), air-spray heat-conduction coefficient λ ₂(tabling look-up, unit: W/m DEG C), air-spray Prandtl number Pr ₂(tabling look-up, dimensionless number);

Then, heat conduction parameters is calculated;

Primary mirror minute surface convective heat-transfer coefficient h _ncalculate:

${\mathrm{Re}}_L^i=\frac{u_L^{i}L}{{\mathrm{\ν}}_1}---\left(1\right)$

Work as Re _l≤ 5 × 10 ⁵time, use equation (2); Work as Re _l>5 × 10 ⁵time, use equation (3);

$h_n=0.664{\left({\mathrm{Re}}_L^i\right)}^{1/2}{{\mathrm{Pr}}_1}^{1/3}\frac{{\mathrm{\λ}}_1}{L}---\left(2\right)$

$h_n=0.037\[{\left({\mathrm{Re}}_L^i\right)}^{4/5}-871\]{{\mathrm{Pr}}_1}^{1/3}\frac{{\mathrm{\λ}}_1}{L}---\left(3\right)$

Primary mirror backboard side convective heat-transfer coefficient h _ccalculate:

$h_c=2{\left(\frac{u_{D}D}{{\mathrm{\ν}}_2}\right)}^{0.5}{{\mathrm{Pr}}_2}^{0.42}{\left(1+0.005{\left(\frac{u_{D}D}{{\mathrm{\ν}}_2}\right)}^{0.5}\right)}^{0.5}\frac{{\mathrm{\λ}}_2}{D}\frac{1-1.1D/r}{1+0.1(H/D-6)D/r}\frac{D}{r}---\left(4\right)$

Finally, above-mentioned parameter is substituted into recurrence equation:

Wherein, $A=\mathrm{\τ}=\frac{k\mathrm{\Δ}t}{\mathrm{\ρ}{C}_p{\mathrm{\Δx}}^2},B=-(1+2\mathrm{\τ}),C=-(1+2\mathrm{\τ}+2\mathrm{\τ}\frac{\mathrm{\Δ}x\·h_C}{k}),D=2\mathrm{\τ}\frac{\mathrm{\Δ}x\·h_C}{k},$ $E=-(1+2\mathrm{\τ}+2\mathrm{\τ}\frac{\mathrm{\Δ}x\·h_n}{k}),F=2\mathrm{\τ}\frac{\mathrm{\Δ}x\·h_n}{k},G=2\mathrm{\τ}\frac{\mathrm{\Δ}x}{k},\mathrm{\τ}=\frac{k}{{\mathrm{\ρC}}_p}\×\mathrm{\Δ}t/{\mathrm{\Δx}}^2,\mathrm{\Δ}x=\frac{L_{thickness}}{N};$

Through one night constant temperature, temperature is identical with environment temperature everywhere to think telescope body, can be used as starting condition, by recursion formula (5), can try to achieve each moment primary mirror mirror temperature

2. a kind of non-contact measurement apparatus measured for heavy caliber helioscope primary mirror mirror temperature according to claim 1, it is characterized in that: environment temperature sensor (3) in device, air-spray temperature sensor (4), built-up radiation sensor (5) and anemoscope (6) are installed in ad-hoc location near primary mirror, directly do not contact with primary mirror.

3. a kind of non-contact measurement apparatus measured for heavy caliber helioscope primary mirror mirror temperature according to claim 1, it is characterized in that: when taking into account computing time, spatial discretization points N, gets little as far as possible, should ensure spatial domain step-length △ x≤1mm.

4. a kind of non-contact measurement apparatus measured for heavy caliber helioscope primary mirror mirror temperature according to claim 1, is characterized in that: time domain step-length △ t value equals each sensor maximum sampling period.

5. a kind of non-contact measurement apparatus measured for heavy caliber helioscope primary mirror mirror temperature according to claim 1, is characterized in that: environmental aerodynamics coefficient of viscosity ν ₁, surrounding air heat-conduction coefficient λ ₁, surrounding air Prandtl number Pr ₁, air-spray dynamics coefficient of viscosity ν ₂, air-spray heat-conduction coefficient λ ₂with air-spray Prandtl number Pr ₂by consulting handbook or adopting the mode of experimental formula to obtain.

6. a kind of non-contact measurement apparatus measured for heavy caliber helioscope primary mirror mirror temperature according to claim 1, is characterized in that: primary mirror minute surface convective heat-transfer coefficient h _nwith primary mirror backboard side convective heat-transfer coefficient h _c, can calculate according to the average environment parameter in a period of time and obtain and substitute into formula as constant, also can calculate renewal in real time according to the environmental parameter recorded in real time.