ASTM E904-87(1995)

Standard Practice for Generating All-Day Thermal Performance Data for Solar Collectors

SCOPE
1.1 This practice provides a means of generating all-day thermal performance data for flat-plate collectors, concentrating collectors, and tracking collectors.  
1.2 The values stated in SI units are to be regarded as the standard. The values given in the parentheses are for information only.  
1.3 This standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

General Information

• Status: Historical
• Publication Date: 30-Jul-1987
• Technical Committee: E44 - Solar, Geothermal and Other Alternative Energy Sources

Relations

• Replaced By: ASTM E904-87(2001) - Standard Practice for Generating All-Day Thermal Performance Data for Solar Collectors
• Effective Date: 31-Jul-1987

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or
withdrawn. Contact ASTM International (www.astm.org) for the latest information.
Designation: E 904 – 87 (Reapproved 1995) An American National Standard
AMERICAN SOCIETY FOR TESTING AND MATERIALS
100 Barr Harbor Dr., West Conshohocken, PA 19428
Reprinted from the Annual Book of ASTM Standards. Copyright ASTM
Standard Practice for
Generating All-Day Thermal Performance Data for Solar
1
Collectors
This standard is issued under the fixed designation E 904; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
and including gaps between reflector segments within a collector module.
1. Scope
Net aperture excludes any shaded area or gaps between reflector segments
1.1 This practice covers a means of generating all-day
and is sometimes called effective aperture area.
thermal performance data for flat-plate collectors, concentrat-
(E 772)
ing collectors, and tracking collectors.
3.1.4 heat transfer fluid, n—in solar energy systems, (1)
1.2 The values stated in SI units are to be regarded as the
liquid or gas that passes through the solar collector and carries
standard. The values given in the parentheses are for informa-
the absorbed thermal energy away from the collector. (2) any
tion only.
fluid that is used to transfer thermal energy between sub-
1.3 This standard does not purport to address all of the
systems in solar energy systems. (E 772)
safety concerns, if any, associated with its use. It is the
3.1.5 non-operational mode exposure, n—condition that
responsibility of the user of this standard to establish appro-
exists when the collector has been filled, then purged of heat
priate safety and health practices and determine the applica-
transfer fluid (if a liquid) and capped (but not sealed) to prevent
bility of regulatory limitations prior to use.
introduction of foreign substances, mounted on a test rack, and
2. Referenced Documents exposed to solar radiation. (E 772)
3.1.6 stagnation conditions, n—conditions (that is, tempera-
2.1 ASTM Standards:
2
ture and pressure) existing when an energy system has attained
E 772 Terminology Relating to Solar Energy Conversion
a quasi-steady state after the flow of heat transfer fluid has
2.2 ASHRAE Standards:
stopped, but the absorber continues to receive significant solar
93-86 Methods of Testing to Determine the Thermal Perfor-
irradiance. (E 772)
mance of Solar Collectors
3.1.7 tilt angle, n—in solar energy applications, angle
96-80 Methods of Testing to Determine the Thermal Perfor-
between the horizontal and the plane of the detector (collector,
mance of Unglazed Flat-Plate Liquid-Type Solar Collec-
3
photovoltaic array, instrument) surface. (E 772)
tors
3.1.8 time constant, n—time required for the temperature
3. Terminology
change in the fluid leaving a solar collector to attain 63.2 % of
its equilibrium value following a step change in the solar
3.1 Definitions:
irradiance or inlet fluid temperature.
3.1.1 Terms from Terminology E 772 and solar nomencla-
ture documents under ballot, are listed for convenience.
NOTE 2—The step change involved should be thoroughly described in
3.1.2 For definitions of other terms used in this practice,
the procedure.
refer to Terminology E 772.
3.2 Definitions of Terms Specific to This Standard:
3.1.3 area, aperture, n—of a solar thermal collector, maxi-
3.2.1 useful energy (removed), n—time integral of the
mum projected area through which the unconcentrated solar
product of mass flow rate, specific heat, and temperature
2
radiant energy is admitted, measured in square metres (m )
difference across the collector when the outlet temperature is
2
(square feet (ft )).
greater than the inlet temperature.
NOTE 1—For concentrating collectors, the gross aperature area includes
4. Summary of Practice
any area of the reflector or refractor shaded by the receiver and its supports
4.1 The solar collector is mounted in accordance with the
1
manufacturer’s instructions. A constant flow rate and inlet
This practice is under the jurisdiction of ASTM Committee E-44 on Solar,
Geothermal, and other Alternative Energy Sources and is the direct responsibility of
temperature, and the transfer fluid, is preselected and specified.
Subcommittee E44.05 on Solar Heating and Cooling Subsystems and Systems.
The temperature, fluid flow rate, irradiance, and wind param-
Current edition approved July 31, 1987. Published December 1987. Originally
eters are recorded throughout the daylight hours. Data are
published as E 904 – 82. Last previous edition E 904 – 82.
2
Annual Book of ASTM Standards, Vol 12.02. collected at 1-min intervals or more frequently, and the average
3
Available from the American Society of Heating, Refrigeration, and Air-
values are report
...