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1、BRITISH STANDARD BS 3533:1981 Glossary of Thermal insulation terms UDC 536.2:001.4 Licensed Copy: sheffieldun sheffieldun, na, Wed Nov 29 03:13:11 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 3533:1981 This British Standard, having been prepared under the direction of the Refrigeration, Heating and
2、 Air Conditioning Standards Committee, was published under the authority of the Executive Board and comes into effect on 27 February 1981 BSI 11-1999 First published August 1962 First revision February 1981 The following BSI references relate to the work on this standard: Committee reference RHE/9 D
3、raft for comment 79/74975 DC ISBN 0 580 11833 9 Cooperating organizations The Refrigeration, Heating and Air Conditioning Standards Committee, under whose direction this British Standard was prepared, consists of representatives from the following: The organizations marked with an asterisk in the ab
4、ove list, together with the following, were directly represented on the Technical Committee entrusted with the preparation of this British Standard: Association of Consulting Engineers.Electricity Supply Industry in England and Association of Manufacturers of DomesticWales* Electrical AppliancesHeat
5、ing and Ventilating Contractors Boiler and Radiator ManufacturersAssociation Association LimitedHevac Association British Combustion EquipmentInstitute of Fuel Manufacturers AssociationInstitute of Refrigeration British Gas Corporation*Institution of Gas Engineers* British Refrigeration and Air Cond
6、itioningLloyds Register of Shipping AssociationManufacturers Association of Radiators it was recognized that the nomenclature employed required definition in order to avoid misrepresentation. In the present revision the text has been brought up to date with technical developments and takes into acco
7、unt the need for harmony with other standard glossaries in related fields published since 1962. It also takes account of current work being undertaken by the International Organization for Standardization (ISO). This glossary is intended to explain terms used in the insulation industry rather than t
8、o provide a full list of relevant scientific definitions. For this reason the term “description” is considered more appropriate than “definition” as normally used in British Standard glossaries. The descriptions are however compatible with the scientific definitions given in BS 874 and other British
9、 Standards publications. Where it has been considered to be helpful, the descriptions have been elaborated by explanatory notes, references and symbols. Where units are indicated (in parentheses at the end of appropriate definitions), these are given in terms of the Systme International dUnits (abbr
10、eviated to “SI units”). For details see PD 5686. The glossary has been divided somewhat arbitrarily into four sections dealing respectively with physical properties, insulating materials, descriptive terms, and fittings and accessory materials. In view of the relative infrequency of associated terms
11、, items in the four sections have been tabulated in alphabetical order and an index has been provided for ease of reference. Preferred terms are printed in bold type, and non-preferred terms in non-bold type. Terms considered undesirable because their use could lead to confusion are followed by the
12、word “deprecated” in italics. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of
13、pages This document comprises a front cover, an inside front cover, pages i and ii, pages 1 to 16, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front co
14、ver. Licensed Copy: sheffieldun sheffieldun, na, Wed Nov 29 03:13:11 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 3533:1981 BSI 11-19991 References The titles of the publications referred to in this standard are listed on the inside back cover. Section 1. Physical properties NOTEFor more detailed d
15、efinitions of a number of the terms relating to thermal properties, see BS 874. No.TermDescription 101absorptivityThe ratio of the amount of radiation absorbed by a surface to the amount falling on the surface. It can refer to radiation of any wavelength but commonly refers to solar radiation. 102ai
16、r permeabilityThe fluid permeability of a material where air is the given fluid. See 113. 103bulk densityThe mass per unit volume of the insulating material (kg/m3). 104compressibilityThe relation between deformation and applied mechanical pressure on a material. 105compressive strength crushing str
17、ength The capacity of a material to withstand mechanical pressure up to the point of fracture. NOTEFor materials that do not fail by shattering, the compressive strength may be deduced arbitrarily from a load/deformation curve. 106convection coefficient (fc)The quantity of heat transferred by convec
18、tion in unit time to or from unit area of surface, divided by the temperature difference between the surface and the surrounding air or other fluid W/(m2K). 107covering capacity (dry)The area covered to unit thickness by unit mass of material as supplied, when it has been applied and dried to consta
19、nt mass in accordance with BS 2972 (m2 per tonne at unit thickness). 108creepProgressive permanent deformation of a material under load. 109dimensional change (expansion or shrinkage) The increase or decrease in a characteristic dimension, which may be measured in linear, superficial or volumetric u
20、nits. 110emissivity (E)The ratio of the thermal radiation from unit area of a surface to the radiation from unit area of a full emitter (“black body”) at the same temperature. 111equivalent thermal conductivityThe thermal conductivity assigned to a hypothetical uniform material of the same dimension
21、s as a particular composite insulation that would give the same rate of heat flow under identical conditions. 112flexural strength modulus of rupture cross-breaking strength The capacity of a material to withstand bending up to the point of fracture. 113fluid permeabilityThe property of a material t
22、hat determines the rate at which a given fluid passes through it under the influence of unit pressure gradient. See 102. 114mean free pathThe average distance travelled by a gas molecule between successive collisions with other molecules. 115nominal thickness designated thickness Manufactured thickn
23、ess within agreed tolerances. Licensed Copy: sheffieldun sheffieldun, na, Wed Nov 29 03:13:11 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 3533:1981 2 BSI 11-1999 No.TermDescription 116packing densityThe bulk density of loose-fill insulating material after application. 117permanent setThe deformati
24、on of a material that remains after removal of the deforming stress. 118porosity (apparent)The volume of open pores in a material expressed as a percentage of the total volume of the material. 119porosity (true)The combined volume of open and closed pores in a material, expressed as a percentage of
25、the total volume of the material. 120radiation coefficient (fr)The net quantity of heat radiated per unit time from unit area of a surface divided by the temperature difference between the radiating surface and the surroundings with which it is exchanging radiation W/(m2K). 121radiation constant ()
26、Stefans constant The constant of proportionality of the Stefan-Boltzman equation relating the radiation loss per unit area of the surface to the fourth power of the absolute temperature of a body. B = 5.67 108W/(m2K4). 122reflectivity (r)The ratio of the amount of thermal radiation reflected from a
27、surface to the amount that falls on the surface. 123resilienceThe ability of a material to recover or partly recover its original dimensions after deformation. 124shape factorA quantity derived from surface area divided by thickness, used in calculating heat transfer by thermal conduction and varyin
28、g with the geometry of the insulation (m). 125surface coefficient (f)Thermal transmission per unit area to or from a surface in contact with air or other fluid, due to convection, conduction and radiation, divided by the difference between the temperature of the surface and the effective ambient tem
29、perature in “steady state” conditions W/(m2 K). NOTE 1The value of the surface coefficient depends on many factors, such as the movement of air or other fluid, the roughness and emissivity of the surface and the temperature and nature of the surroundings. NOTE 2The term “effective ambient temperatur
30、e” is used to indicate that the actual measured temperature may need to be corrected for factors such as atmospheric humidity, solar radiation and wind velocity before comparable results can be obtained. 126surface resistance (1/f)The reciprocal of surface coefficient (see 125). 127tensile strengthT
31、he capacity of a material to withstand tension up to the point of fracture. 128thermal capacityThe quantity of heat required to raise the temperature of a given structure or quantity of material by 1 K. 129thermal capacity per unit mass (c) specific heat capacity The quantity of heat required to rai
32、se the temperature of unit mass by 1 K J/(kg K). 130thermal capacity per unit volume Thermal capacity per unit mass multiplied by bulk density J/(m3K). Licensed Copy: sheffieldun sheffieldun, na, Wed Nov 29 03:13:11 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 3533:1981 BSI 11-19993 No.TermDescript
33、ion 131thermal conductance (C)The thermal transmission through unit area of a slab of material, or of a structure, divided by the temperature difference between the hot and cold faces in “steady state” conditions W/(m2K). NOTE 1When the hot face and the cold face are not equal in area, e.g. the inte
34、rnal and external surfaces of insulation on a box or pipe, it is necessary to state the position at which the area is measured. NOTE 2Thermal conductance depends upon the actual thickness of the material or structure, whereas thermal conductivity refers to unit thickness of the material. 132thermal
35、conductivity ()The thermal transmission through unit area of a slab of a uniform material of unit thickness when unit difference of temperature is established between its faces W/(m K). NOTE 1Thermal conductivity was formerly given the symbol k. NOTE 2W/(m K) is a simplification of W m/m2K). 133ther
36、mal diffusivity (!)Thermal conductivity divided by thermal capacity per unit volume (m2/s). 134thermal resistance (R)The reciprocal of thermal conductance. 135thermal resistivity (1/)The reciprocal of thermal conductivity. 136thermal transmission (q) heat flux The quantity of heat flowing in unit ti
37、me (W). 137thermal transmittance (U) overall heat transfer coefficient The thermal transmission through unit area of a given structure divided by the difference between the effective ambient temperatures on either side of the structure in “steady state” conditions W/(m2K). NOTE 1If the structure is
38、not a simple slab, it is necessary to state where the area is measured. NOTE 2“Transmittance” differs from “conductance” because the temperature difference is measured between different positions. For conductance the temperature difference is that between the faces; for transmittance it is that betw
39、een the effective ambient temperatures on either side of the structure. Thus the thermal transmittance (U) of a structure involves both the thermal conductance and the surface coefficient of the structure. NOTE 3The term “effective ambient temperature” is used to indicate that the actual measured te
40、mperature may need to be corrected for factors such as atmospheric humidity, solar radiation and wind velocity before comparable results can be obtained. The U-value is normally referred to a particular combination of these factors. 138total thermal resistance (1/U)The sum of the surface resistances
41、 and the thermal resistance of the structure itself. 139U-valueA conventionally used value of thermal transmittance of a structure related to design conditions. NOTEFor calculation of standardized U-values, reference should be made to Building Research Establishment Digest no. 108. 140vapour permean
42、ceThe property of a material that determines the rate at which vapour passes through it under the influence of unit partial water vapour pressure difference across the specimen g/(s MN). NOTEFor water vapour permeance conversion factors see BS 2972. 141vapour permeabilityThe vapour permeance of a ma
43、terial per unit thickness g m/(s MN). See also BS 3177. 142vapour resistanceThe reciprocal of vapour permeance (see 140). 143vapour resistivityThe reciprocal of vapour permeability (see 141). Licensed Copy: sheffieldun sheffieldun, na, Wed Nov 29 03:13:11 GMT+00:00 2006, Uncontrolled Copy, (c) BSI B
44、S 3533:1981 4 BSI 11-1999 Section 2. Insulating materials No.TermDescription 201aluminium foilThin sheets of rolled aluminium (0.15 mm thick and under). 202aluminium silicate fibreFilaments or fibres produced from a melt of alumina and silica. 203animal hairNatural fibre obtained from the coats of a
45、nimals (see also wool, 276). 204asbestosThe generic name for those silicate minerals that cleave naturally into fibres, the three important forms being chrysotile (white asbestos), crocidolite (blue asbestos) and amosite. 205asbestos insulating boardA board containing a large percentage (by mass) of
46、 asbestos fibre, normally bonded with an inorganic bonding agent substantially insoluble in water. 206asbestos millboardBoard based on a mix that consists mainly of asbestos fibre and a binder (frequently organic). Fillers may be included. 207asbestos paperPaper-like material of which the main const
47、ituent is asbestos fibre. 208blowing woolGranulated wool (see 230) for application by blowing. 209calcium silicate insulationHydrated calcium silicate with added reinforcing fibres. 210cellular asbestos paperSheet insulation formed by combining alternate sheets of flat with corrugated asbestos paper
48、, and securing the adjacent sheets together at their points of contact by means of an adhesive. 211cellular glass foamed glass A lightweight expanded glass with small cells, preferably non-intercommunicating, produced by a foaming process. 212cellular plastics expanded plastics foamed plastics A gen
49、eric term for plastics material of which the density is reduced by the presence of numerous small cavities (cells), interconnecting or not, dispersed throughout the mass. NOTESee BS 1755 for individual definitions. 213cellular rubberA generic term for vulcanized rubber containing numerous thin-walled cells filled with air or other gas. The walls of the cells may be vulcanized to the soft rubber stage or completely to the hard rubber (ebonite) stage. 214ceramic fibreFibrous material, loose or fabricated into convenient forms, mainly intended for u
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