1、INTERNATIONAL STANDARD IS0 9459-2 First edition 1995-08-I 5 Solar heating - Domestic water heating systems - Part 2: Outdoor test methods for system performance characterization and yearly performance prediction of solar-only systems Chauffage solaire - Syst the procedures are therefore suitable for
2、 testing all types of systems, including forced circulation, thermosiphon, freon-charged and integrated collector-storage systems. This part of IS0 9459 is not intended to be used for testing solar heating systems which have an auxiliary heater as an integral part of the system, since the operation
3、of the auxiliary input may influence the performance of the solar heating system. To quantify the interaction between the energy inputs, the test procedure described in IS0 9459-3 is recommended. This part of IS0 9459 applies to solar-only domestic water heating systems designed to heat potable wate
4、r to be supplied for domestic water usage and is not intended to be applied to other systems. The test procedures are applicable only to systems of 0,6 m3 of solar storage capacity or less. The test procedures in this part of IS0 9459 do not require the solar water heating system to be subjected to
5、freezing conditions. Consequently, the energy consumed or lost by a system while operating in the freeze- protection mode is not determined. This part of IS0 9459 is not generally applicable to concentrating systems. It is not intended to be used for testing the individual components of the system,
6、nor is it intended to abridge any safety or health requirements. 2 Normative references The following standards contain provisions which, through reference in this text, constitute provisions of this part of IS0 9459. At the time of publication, the editions indicated were valid. All standards are s
7、ubject to revision, and parties to agreements based on this part of IS0 9459 are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and IS0 maintain registers of currently valid International Standards. 1 IS0 9459-2: 1995(E
8、) Q IS0 IS0 9060:1990, Solar energy - Specification and classification of instruments for measuring hemispherical solar and direct solar radiation. IS0 9459-3: -11, Solar heating - Domestic water heating systems - Part 3: Performance test for solar plus supplementary systems. IS0 9846:1993, Solar en
9、ergy - Calibration of a pyranometer using a pyrheliometer. IS0 9847:f 992, Solar energy - Calibration of field pyranometers by comparison to a reference pyranometer. ISOflR 9901: 1990, Solar energy - Field pyranometers - Recommended practice for use. IS0 11924:-J, Solar heating - Domestic water heat
10、ing systems - Test methods for the assessment of reliability and safety. World Meteorological Organization, Guide to Meteorological Instruments and Methods of Observation, No. 8, 5th edition, WMO, Geneva, 1983, Chapter 9 - World Radiometric Reference, known as the WRR. 3 Definitions As stated in the
11、 Introduction, each part of IS0 9459 has been conceived as a self-contained document. Therefore, some of the terms with their definitions given in this clause may also appear in other part(s) of IS0 9459. For the purposes of this International Standard, the following definitions apply. 3.1 absorber:
12、 Device within a solar collector for absorbing radiant energy and transferring this energy as heat into a fluid. 3.2 accuracy: Ability of an instrument to indicate the true value of the measured physical quantity. 3.3 ambient air: Air in the space (either indoors or outdoors) surrounding a thermal e
13、nergy storage device, a solar collector, or any object being considered. 3.4 angle of incidence (of direct solar radiation): Angle between the solar radiation beam and the outward-drawn normal from the plane considered. NOTE 1 Angle of incidence is often termed “incidence angle” or “incident angle”.
14、 The use of these terms is deprecated. 3.5 aperture area: Maximum projected area through which the unconcentrated solar radiation enters a collector. 3.6 aperture plane: Plane at or above the solar collector through which the unconcentrated solar radiation is admitted. 3.7 auxiliary energy: See auxi
15、liary (heat) source. 3.8 auxiliary (heat) source: Source of heat, other than solar, used to supplement the output provided by the solar energy system. 3.9 collector: Device containing an absorber. 3.10 collector tilt angle: Angle between the aperture plane of a solar collector and the horizontal pla
16、ne. 3.11 components: Parts of the solar hot water system including collectors, storage, pumps, heat exchanger, controls, etc. I) To be published. 2 IS0 9459-Z: 1995( E) 3.12 concentrating collector: Solar collector that uses reflectors, lenses or other optical elements to redirect and concentrate th
17、e solar radiation passing through the aperture onto an absorber, the surface area of which is smaller than the aperture area. 3.13 differential temperature controller: Device that is able to detect a small temperature difference, and to control pumps and other electrical devices in accordance with t
18、his temperature difference. 3.14 domestic: For use in residential and small commercial buildings. 3.15 draw-off rate; water draw-off rate: Rate at which water is withdrawn from a water heating system. 3.16 draw-off temperature: Temperature of hot water withdrawn from the system. 3.17 evacuated tube
19、tubular collector: Solar collector employing transparent tubing (usually glass) with an evacuated space between the tube wall and the absorber. The absorber may consist of an inner tube or another shape, with means for removal of the thermal energy. The pressure in the evacuated space is usually les
20、s than 1 Pa. 3.18 flat plate collector: Non-concentrating solar collector in which the absorbing surface is essentially planar. 3.19 fluid transport: Transfer of air, water, or other fluid between components. 3.20 gross collector area: Maximum projected area of a complete solar collector, excluding
21、any integral means of mounting and connecting fluid pipework. For an array or assembly of flat plate collectors, evacuated tubes or concentrating collectors, the gross area in- cludes the entire area of the array, i.e. also borders and frame. 3.21 heat exchanger: Device specifically designed to tran
22、sfer heat between two physically separated fluids. Heat exchangers can have either single or double walls. 3.22 heat transfer fluid: Fluid that is used to transfer thermal energy between components in a system. 3.23 irradiance: Power density of radiation incident on a surface, i.e. the quotient of t
23、he radiant flux incident on the surface and the area of that surface, or the rate at which radiant energy is incident on a surface, per unit area of that surface. It is expressed in watts per square metre. NOTE 2 Solar irradiance is often termed “incident solar radiation intensity”, “instantaneous i
24、nsolation”, “insolation” or “in- cident radiant flux density”; the use of these terms is deprecated. 3.24 irradiation: Incident energy per unit area of a surface, found by integration of irradiance over a specified time interval, often an hour or a day. It is expressed in megajoules per square metre
25、 NOTE 3 Solar irradiation is often termed “radiant exposure” or “insolation”; the use of these terms is deprecated. 3.25 load: Heat supplied to the user, for example in the form of hot water. NOTE 4 Because of heat losses in the distribution system, the location of the heat delivery must be specifi
26、ed. 3.26 long-wave radiation: Radiation at wavelengths greater than 3 pm, typically originating from sources at terrestrial temperatures (e.g. ground and other terrestrial objects); sometimes called “thermal radiation”. 3.27 precision: Measure of the closeness of agreement among repeated measurements of the same physical quantity. 3
