GB/T 34334-2017 PDF in English
GB/T 34334-2017 (GB/T34334-2017, GBT 34334-2017, GBT34334-2017)
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Test method of mirror shape for solar collector
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Standards related to (historical): GB/T 34334-2017
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GB/T 34334-2017: PDF in English (GBT 34334-2017) GB/T 34334-2017
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 81.040.30
Q 34
Test method of mirror shape for solar collector
ISSUED ON. OCTOBER 14, 2017
IMPLEMENTED ON. SEPTEMBER 1, 2018
Issued by. General Administration of Quality Supervision, Inspection and
Quarantine;
Standardization Administration Committee.
Table of Contents
Foreword . 3
1 Scope .. 4
2 Terms and definitions .. 4
3 Symbols.. 5
4 Test principle .. 6
5 Instruments .. 6
6 Testing process .. 11
7 Parameter calculation .. 11
8 Test report .. 18
Foreword
This Standard was drafted in accordance with the rules given in GB/T 1.1-2009.
This Standard was proposed by China Federation of Building Materials.
This Standard shall be under the jurisdiction of National Technical Committee
on Industrial Glass and Special Glass of Standardization Administration of
China (SAC/TC 447).
The drafting organizations of this Standard. Beijing Aobotai Technology Co.,
Ltd., China Building Materials Inspection & Certification Group Co., Ltd., China
Haiyang Energy Group Co., Ltd., China Guangdong Nuclear Power
Development Co., Ltd.
Main drafters of this Standard. Bo Cong, Wang Jingjing, Zhang Zhemin, Li
Menglei, Wang Shanshan, Lu Jun, Zhang Yuxia, Yuan Jing, Wang Dong, Qiu
Juan, Li Boye, Li Yang, Wang Lichuang, Yang Fan, Feng Tian, Fu Lu, Zhu
Xiaowei, Zhang Ji, Yang Hui, Qi Bin.
Test method of mirror shape for solar collector
1 Scope
This Standard specifies the terms and definitions, symbols, test principle,
instruments, test procedures, parameter calculation and test report of mirror
shape for solar collector based on stripe reflection principle.
This Standard is applicable to the tests of mirror shape for slot, dish, tower solar
collectors.
2 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
2.1 height deviation
height deviation in the reference direction between the actual mirror and the
ideal mirror
2.2 slope
the tangent of the angle between the tangent plane and the reference plane at
a point on the reflector
2.3 slope deviation
the angle between the actual mirror normal and the ideal mirror normal at a
point on the mirror
2.4 focus deviation
under use conditions, the distance from the reflected light to the mirror's ideal
focus or focal line
2.5 focus deviation distribution
the distribution of focus point deviation of the mirror on the reference plane
2.6 parallel ray intercept factor
parallel light rays evenly distributed along the ideal direction of incidence, the
ratio of the amount of light reflected by the mirror to the heat sink to the amount
of light incident on the mirror
2.7 sun intercept factor
the ratio of the amount of sunlight reflected in the ideal direction of incidence to
the heat sink by the mirror TO the amount of light incident on the mirror
2.8 intercept factor distribution
take the diameter of the heat-absorbing device as the abscissa, the actual
mirror-parallel light-cutting factor of the corresponding caliber as the ordinate,
form the distribution curve of the parallel light-cutting factor under different
caliber conditions
2.9 concentrating quality factor
the ratio of the area under the actual mirror parallel light cut-off factor
distribution curve TO the area under the ideal mirror parallel light cut-off factor
distribution curve with a use aperture of the heat-absorbing device as the
boundary condition of the parallel light cut-off factor distribution curve
3 Symbols
The following symbols apply to this document.
CQF. concentrating quality factor
FDx. mean square root of focus deviation in x-axis direction in the use
coordinate system (xyz)
fdx (X, Y). focus deviation distribution in X-axis direction in the measurement
coordinate system (XYZ)
FDy. mean square root of focus deviation in y-axis direction in the use
coordinate system (xyz)
fdy (X, Y). focus deviation distribution in Y-axis direction in the measurement
coordinate system (XYZ)
HD. mean square root of height deviation in the measurement coordinate
system (XYZ)
hd (X, Y). mirror height deviation distribution in the measurement coordinate
system (XYZ)
IC. parallel ray intercept factor
ICsun. sun intercept factor
RIC(φ). parallel ray intercept factor distribution of heat absorption device
g (X, Y) - the slope at some fixed point (X, Y) on the tested mirror; its modulus
value is calculated according to equation (4).
5.2.4 Obtain mirror shape parameters
5.2.4.1 According to the mirror shape obtained from the measurement
coordinate system, the following parameters can be calculated. height deviation
distribution hd(X, Y), mean square root of height deviation HD, slope deviation
distribution sdX(X, Y) in the X axis direction, slope deviation distribution sdY(X,
Y) in the Y axis direction, mean square root of slope deviation in X-axis direction
SDX, mean square root of slope deviation in Y-axis direction SDY, focus
deviation distribution in X-axis direction fdX (X, Y), focus deviation distribution
in X-axis direction fdY (X, Y).
5.2.4.2 Convert the slope distribution gx (X, Y), gy (X, Y) in the measurement
coordinate system XYZ to the slope distribution gx (x, y), gy (x, y) in the use
coordinate system xyz according to the use requirements. In the use coordinate
system xyz, the z-axis is the direction of the ideal incident light, the y-axis is the
mirror bus direction, and the x-axis is the vertical yoz plane direction. Use linear
interpolation or area projection weighing methods, in the use coordinate system
xyz plane, according to the parameter calculation requirements, form an equal
interval slope distribution. Combined with the sun divergence angle and the
diameter of the heat collector, the following parameters can be calculated.
mean square root of focus deviation in x-axis direction FDx, mean square root
of focus deviation in y-axis direction FDy, parallel ray intercept factor IC, sun
intercept factor ICsun, parallel ray intercept factor distribution of heat absorption
device RIC(φ), concentrating quality factor CQF.
5.3 Requirements
5.3.1 Sample bench
The sample bench shall satisfy the positioning installation of the tested sample.
The sample positioning accuracy shall be less than 1mm.
5.3.2 Graphic generator
The graphic generator can be implemented by a display or projection method
that can generate a dynamic pattern. The display area shall meet the complete
reflective mirror test of the tested sample.
sdX - the slope deviation of the surface test point of the test sample in the X-
axis direction, in milliradians (mrad);
β'X - the angle between the projection direction of the test point's measured
normal on the XOZ plane and the Z-axis, in milliradians (mrad);
βX - the angle between the projection direction of the test point's ideal normal
on the XOZ plane and the Z axis, in milliradians (mrad).
See equation (8) for the calculation of the mean square root of slope deviation
of the tested sample SDX in X-axis direction.
where,
SDX - the mean square root of slope deviation of the tested sample, in
milliradians (mrad);
sdxi - the slope deviation of a certain test point on the surface of the test sample
in the direction of the X-axis direction, in milliradians (mrad);
n - total number of test points.
The slope deviation distribution sdX (X, Y) in the X-axis direction is the
distribution of the slope deviation of each test point on the sample surface on
the XOY coordinate plane sdXi, represented in two-dimensional error map.
7.2.2 Mean square root of slope deviation in Y-axis direction SDY
In the measurement coordinate system, the slope deviation of the test point on
the tested sample surface in Y-axis direction sdY is equal to the angle between
the actual normal direction and the ideal normal direction of the test point on
the YOZ projection plane. See equation (9) for the calculation.
where,
sdY - the slope deviation of the test point on the tested sample surface in Y-axis
direction, in milliradians (mrad);
β'Y - the angle between the actual measured normal of test point on the
projection direction of YOZ and the Z-axis, in milliradians (mrad);
7.3.3 Mean square root of focus deviation in y-axis direction FDy
See equation (13) for the calculation of focus deviation fdY in the Y direction.
where,
fdY - the focus deviation of the test point on the tested sample surface along
with the Y direction, in millimeters (mm);
sdY - the slope deviation of the test point on the tested sample surface in the Y
direction, in milliradians (mrad);
L - the distance from the test point on the tested sample surface to the ideal
focus or focal line, in millimeters (mm).
Convert the measurement coordinate system to use coordinate system.
Interpolation and other methods can be used to achieve uniform light sampling
and obtain the focus deviation fdY in the use coordinate system. The mean
square root of focus deviation in y-axis direction FDy is calculated according to
equation (14).
where,
FDy - the mean square root of focus deviation of tested sample in the y-axis
direction;
fdYi - the focus deviation of a test point on the tested sample surface along with
the Y direction;
m - total number of data points.
Use XOY plane as reference plane. The focus deviation distribution on the Y-
axis direction fdY (X, Y) is the distribution of the focus deviation of each test
point on the sample surface on the XOY coordinate plane fdYi, represented in
two-dimensional error map.
7.4 Intercept factor calculation
7.4.1 Calculation principle
The intercept factor can be calculated by ray tracing simulation, and the number
...... Source: Above contents are excerpted from the PDF -- translated/reviewed by: www.chinesestandard.net / Wayne Zheng et al.
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