Some standard content:
ICS_91.120.10
National Standard of the People's Republic of China
GB/T4132-1996
Thermal insulating materials and related terms
Definitions of terms relating to thermal insulating materials
Issued on 1996-09-13
State Administration of Technical Supervision
Implemented on 1997-04-01
GB/T4132-1996
Cited Standards
Definition Notes
Thermal insulating materials, products and systems
Physical and mechanical properties of thermal insulating materials, products and systems 5
Heat transfer and mass transfer
Appendix A (Suggestive Appendix)
Chinese Pinyin Index
Appendix B (Suggestive Appendix)
English Index Cited
GB/T4132-1996
This standard adopts the series of standards ISO7345:1987 "Thermal insulation - physical quantities and definitions", ISO9229:1991 "Thermal insulation - materials, products and systems - vocabulary", ISO9251:1987 "Thermal insulation - heat transfer conditions and material properties - vocabulary", ISO9288:1989 "Thermal insulation - radiation heat transfer - physical quantities and definitions", ISO9346:1988 "Thermal insulation - mass transfer - physical quantities and definitions". ISO9288:1989 "Thermal insulation - radiation heat transfer - physical quantities and definitions", ISO9346:1988 "Thermal insulation - mass transfer - physical quantities and definitions" are only part of the terms related to the application of thermal insulation materials. For some terms related to the application of thermal insulation materials that are not included in the above ISO standards, refer to ASTM C168-88a "Terms and definitions of thermal insulation materials", BS 3533-81 "Terms and definitions of thermal insulation materials" and ISO TR 9774 "Terms and definitions of thermal insulation materials - Application categories and basic requirements - Guide to coordination with international standards and other specifications".
The terms and definitions of thermal quantities in this standard are consistent with GB 3102.4-93 "Thermal quantities and units", except for 6.2.7 thermal resistance. The definition of thermal resistance in this standard is the term commonly used in the thermal insulation materials and construction industry, and is consistent with the international terminology. In this revision, the terms are not limited to the materials themselves, but also include terms related to the use of materials. Therefore, this standard is renamed "Thermal insulation materials and related terms".
This standard makes necessary modifications to GB/T 4132-84 "Terms and definitions of thermal insulation materials": (1) 4.10 boldface, defined in accordance with ISO 9288. (2) 5.4 The original GB/T4132-84 was "linear drying shrinkage", which has been corrected to "drying linear shrinkage". (3) 6.1.1 Steady state, 6.1.2 Non-stable state, 4.3 Homogeneous material, 4.4 Non-homogeneous material, 4.5 Isotropic material, 4.6 Anisotropic material. The above terms in this standard are defined in accordance with ISO9251, and are not limited to heat transfer performance, but also include mass transfer performance, which is different from the original GB/T4132-84 which is limited to thermal performance.
(4) 6.2.1 Heat, heat. The symbol for heat is defined as "Q", which is consistent with GB3102.4 and ISO7345. (5) 6.2.2 Heat flow. The symbol for heat flow is defined as "@", which is consistent with GB3102.4 and ISO7345. (6) 6.2.3 Heat flux density. The \\ symbol in GB3102.4 is cancelled, and only the symbol "g" is retained. At the same time, the English term "heatflux" in the brackets of the original GB/T4132-84 is cancelled, which is consistent with ISO7345. (7) 6.2.14 Thermal conductivity. The symbol is changed to A, which is the same as ISO7345, and the synonym "heat transfer coefficient" is added. (8) 6.3.4 Total hemispherical emissivity (blackness). It was mistakenly written as thermal diffusivity in the original GB/T413284, and it is now corrected. (9) 6.3.7 Total absorptivity, 6.3.8 Total reflectivity. The symbol of total absorptivity is "α" and the symbol of total reflectivity is "p", which is consistent with ISO9288 and GB3102.
(10) The synonym "moisture conductivity coefficient" of "4.18 moisture diffusion coefficient" in the original GB/T4132-84 is cancelled. The "moisture conductivity coefficient" in this standard is defined separately (see 6.4.17 moisture conductivity coefficient).
(11) Delete "4.20\Bulk density" in GB/T4132-84. This standard replaces GB/T4132-84. GB/T4132-84 will be invalidated from the date of implementation of this standard. This standard was proposed by the National Committee for Standardization of Thermal Insulation Materials (CSBTS/TC191). This standard is under the jurisdiction of the National Committee for Standardization of Thermal Insulation Materials (CSBTS/TC191). The drafting units of this standard are Henan Building Materials Research and Design Institute and Standardization Institute of the State Building Materials Bureau. The main drafters of this standard are Cao Sheng, Wang Qiaoyun and Chen Aizhu. 1 Scope
National Standard of the People's Republic of China
Definitions of terms relating to thermal insulation materials and related terms
thermalinsulatingmaterials
This standard defines the terminology, symbols and units of thermal insulation materials and related physical quantities. GB/T4132-1996
Replaces GB4132-84
This standard applies to technical documents such as standards, specifications, test identification and design of thermal insulation materials. 2 Cited standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard, and the versions shown are valid when the standard is published. All standards will be revised, and parties using this standard should explore the possibility of using the latest versions of the following standards. GB3102.4-93 Thermal quantities and units
3 Definitions
Terms not defined in this standard shall be in accordance with the provisions of GB3102.4-93. 4 Thermal insulation materials, products and systems
4.0 Thermal insulation material thermalinsulatingmaterial A functional material used to reduce heat exchange between structures and the environment. 4.1 Porous material porousmaterial||tt| |Multiphase material with well-dispersed solid phase and pores. 4.1.1 Fibrous porous material fibrousporousmaterial Material composed of a continuous gas phase and a fibrous solid phase. 4.1.2 Granular loose fill material granularloosefillmaterial Material composed of a continuous gas phase and a granular solid phase. 4.1.3 Cellular porous material cellularporousmaterial Material composed of a continuous solid phase and approximately circular pores containing gas. Interconnected porous material4.1.4
Material composed of a continuous solid phase and a gas phase containing interconnected pores. 4.2 Homogeneous porous material, homogeneousporousmaterial Material whose local porosity is independent of position. Note: See 5.3.
4.3 Homogeneous material homogeneousmaterial Material whose relevant properties are independent of the position inside the material, but can change with time, direction, temperature, etc. 4.4 Heterogeneous material: Material whose relevant properties change with the position inside the material. Approved by the State Administration of Technical Supervision on September 13, 1996 and implemented on April 1, 1997
4.5 Isotropic material isotropic material GB/T4132-1996
Material whose relevant properties are independent of direction but can change with the position, time, temperature, etc. inside the material. 4.6 Anisotropic material anisotropic material Material whose relevant properties change with direction.
4.7 Stable material stable material
Material whose relevant properties do not change with time but can change with coordinates, direction, temperature, etc. 4.8 Opaque material opaque material
Material that does not transmit any incident thermal radiation energy. Note: The absorption, emission and reflection of thermal radiation are treated as surface phenomena. 4.9 Semi-transparent material semi-transparent material Material whose thermal radiation enters the interior of the material and is gradually weakened due to absorption or scattering. Note ① The absorption, scattering and emission of thermal radiation are internal phenomena of objects. ② Insulating materials are generally semi-transparent materials. 4.10 Blackbody blackbody; fullradiator; plankradiator An ideal object that absorbs incident radiation energy of all wavelengths, directions and polarization waves and has maximum radiation power for any wavelength at a given temperature.
Greybody greybody
An object with the same hemispherical, directional or spectral emissivity for all wavelengths at a given temperature. Note: See 6.1.7 and 6.3.4.
4.12 Mineral fiber mineralfibre
A general term for all inorganic non-metallic fibers made from minerals. 4.12.1 Asbestos fiber asbestosfibre
Fiber material obtained from asbestos minerals. Serpentine asbestos is commonly used as thermal insulation material. 4.12.2 Man-made mineral fiber man-mademineralfibre A general term for inorganic fibers made from rocks, slag (industrial waste), glass, metal oxides or porcelain clay. 4.12.2.1 Glass fiber glassfibre
Mineral fiber made from molten glass.
4.12.2.2 Ceramic fiber ceramic fiber Mineral fiber made from molten metal oxide or porcelain clay, such as ordinary aluminum silicate fiber, high aluminum fiber, etc. 4.13 Carbon fiber carbon fiber
Fiber made by carbonization of organic insulation fiber. Graphite fiber graphite fiber
Carbon fiber treated by heat stabilization at graphitization temperature. Cellulose insulation material cellulosic insulation; cellulose insulation 4.141
Fiber insulation material obtained from plant fibers such as paper, cardboard or wood. 4.15 Mineral wool mineral wool
General term for cotton-like fibers made from molten rock, slag (industrial waste), glass, metal oxide or porcelain clay. 4.15.1 Glass wool glass wool
A mineral wool made from molten glass. 4.15.2 Slag wool slag wool
A mineral wool made from molten slag. Rockwool rockwool
A mineral wool mainly made from molten natural igneous rock. 2
GB/T4132-1996
4.15.4 Aluminum silicate wool aluminumsilicatewool A mineral wool made from molten aluminum silicate mineral. 4.15.5 Granulated wool granulatedwool
Spherical or nodular loose mineral wool processed by machinery. 4.16 Cellularmaterial A material containing a large number of evenly distributed pores (open pores, closed pores or both) throughout the volume. 4.16.1 Cellularglass A hard insulating material made from molten glass powder or glass rock powder with a closed pore structure as the main structure. 4.16.2
Cellularplastics;plasticsfoam A plastic with a large number of pores distributed throughout the entire volume to reduce the density. 4.16.2.1
Polystyrene foam Cellular polystyrene Polystyrene foam, expanded polystyrene Foam plastics with polystyrene resin or its copolymer as the main component. Polyvinyl chloride foam Cellular polyvinyl chloride Expanded polyvinyl chioride 4.16.2.2
Foam plastics with vinyl chloride copolymer as the main component. 4.16.2.3 Phenolic foam Phenolic foam Rigid foam plastics made of condensation products of phenol and formaldehyde (soluble phenolic resin and linear phenolic resin) as the main component.
Polyisocyanurate foam Polyisocyanurate foam Rigid foam plastics with copolymers of isocyanates arranged in a repeating structural chain as the main component. 4.16.2.5 Polyurethane foam Polyurethane foam; cellular polyurethane Rigid or flexible foam plastics with urethane/isocyanate polymer as the main component. 4.16.2.6 Polyethylene foam cellularpolyethlene; polyethlenefoam Foam plastic with polyethylene as the main component. 4.16.3 Foam rubber cellularelastomericexpendedrubber; cellularrubber; foamedrubber Foam material made of natural or synthetic rubber as the main component. 4.16.4 Foam asbestosfoam
Foamed product made of chrysotile asbestos as the main component. 4.17 Diatomaceous silicate Porous sediment composed of residual diatom fossils. 4.18 Diatomaceous insulation products diatomaceousinsulation Insulation products made of diatomaceous earth as the main component: 4.19 Calcium silicate insulation products calciumsilicateinsulation Insulation products with hydrated calcium silicate formed by autoclaving as the main component and mixed with reinforcing fibers, divided into tobermorite type, xonotlite type and wollastonite type according to the different hydration products of the products. Expanded perlite
A granular porous thermal insulation material made by roasting and expanding natural acidic volcanic ash glass rock (i.e. perlite). 4.21
Expanded perlite thermal insulation products'expandedperliteinsulation Thermal insulation products made of expanded perlite as the main component and an appropriate amount of binder. 4.22 Expanded vermiculiteexpandedvermiculitezexfolialedvermiculite A layered granular thermal insulation material made by roasting and expanding vermiculite. 4.23
Expanded vermiculite productsexpandedvermiculiteinsulation Thermal insulation products made of expanded vermiculite as the main component and an appropriate amount of binder. 4.24Cork
GB/T4132-1996
A thermal insulation material made from the bark of cork oak or yellow pineapple tree. 4.24.1 Granulated cork Cork ground into small particles or small particles. Cork products corkinsulation
Products made by combining granular cork under certain temperature and pressure conditions. 4.25 Haydite
Granular porous insulation material (lightweight aggregate) made by roasting and expanding minerals. 4.25.1 Clay expandedclay
Granular porous insulation material made by roasting and expanding clay. Fly ash expandedflyash
Granular porous insulation material made by roasting and expanding fly ash. 4.25.3 Shale expandedshale
Granular porous insulation material made by roasting and expanding shale. 5 Foamed gypsum (lime) foamedgypsum 4.26
Porous insulation material made of semi-hydrated gypsum or ground lime as the main raw material. 4.27 Insulating concrete A general term for all types of porous lightweight concrete. Such as aerated concrete, foamed concrete, etc. 4.28 Aluminum foil Aluminum foil
Thin aluminum sheets with a thickness of less than 0.15 mm are often used as reflective insulation layers. 4.29 Insulating mortar Insulating plaster A mortar made of granular insulating materials as aggregates and cementitious materials. 4.30 Insulating coating (dry) Insulating cement (US); plastic composition (UK) A mixture of dry fibers, particles and powdered materials, which can form a plastic slurry after adding water and stirring on site, and form an insulation layer after being applied and dried on site.
Silicate insulating coating Insulating cement (wet) 4.30.17
A slurry made of silicate mineral fibers, particles and powdered materials as the main components, mixed with cementitious materials and other additives, which forms an insulation layer after being applied and dried on site. Insulation brick (block) block insulation || tt || solid insulation products with no significant difference in length, width and thickness. Insulation board board insulation, slab insulation; sheet insulation 4.32
Solid insulation products whose thickness is significantly smaller than their length and width. Insulating pipe shells and tubes
Products used for pipe insulation with an annular, semi-annular or fan-shaped cross section. Curved board insulation4.34
Hard insulation products with an arc-shaped cross section, usually with an inner diameter exceeding 1m. Slotted slab insulation4.35
Insulating boards with semicircular, rectangular, triangular or wedge-shaped grooves for curved surfaces. 4.36 Insulating rope insulating rope
General term for rope-like products woven from fiber insulation materials. Insulating felt batt insulation; blanket insulation; mat insulation4.37
General term for flexible felt-like products made of fiber materials. Metal mesh insulation blanketmetalmeshblanket4.37.1
Insulation blanket with flexible metal mesh on one or both sides. 4
4.37.2 Lamellaproduct
GB/T4132--1996
Artificial mineral fiber products made by needle punching process. 4.38 Composite insulation composite insulation has two or more layers of different materials. 4.39 Loose-fill insulation loose-fill insulation formed by filling loose particles (including powder) or fiber insulation materials in the cavity or interlayer. 4.40 Microporous insulation microporous insulation is an insulation layer composed of fine powdery or fibrous materials, and the average size of its interconnected pores is equivalent to or lower than the mean free path of air molecules under standard atmospheric pressure (the order of 0.1μm). 4.41 Reflective insulation layer reflective insulation layer has one or more layers of high reflectivity and low emissivity surface to reduce radiation heat transfer. Sprayed insulation layer sprayed insulation layer
Insulation layer formed by spraying insulation material onto the surface in use. 4.43 Vacuum insulation layer vacuum insulation layer vacuum sealed insulation layer.
4.43.1 Powder filled vacuum insulation layer
vacuum powder insulation layer
vacuum insulation layer filled with powdered material. 4.43.2 Vacuum reflective insulation layer vacuum reflective insulation layer with reflective foil or film to reduce radiation heat transfer. 4.43.3 High-vacuum insulation layer high-vacuum insulation layer sealed insulation layer with internal air pressure lower than 0.1Pa, the inner surface of which should be a low-emissivity surface. 4.44 Foamed-in-place insulation layer: a rigid foam insulation layer formed by gradually foaming and curing the liquid material after spraying or pouring on site. 4.45 Radiation shield: a sheet product with low emissivity to reduce radiation heat transfer. 4.46 Water vapor barrier; water vapor retarder: a material or system used to prevent the migration of water vapor. Facing
: the protective and decorative layer outside the insulation material. 4.48 Outer protective layer: insulation jacket: the outermost protective and decorative layer of the insulation system made of fiber, film, or thin metal. 5 Physical and mechanical properties of insulation materials, products, and systems 5.1 Density (p) density
: the mass of a unit volume of material, kg/m2.
5.1.1 Bulk density bulkdensity
: the mass of a unit volume of loose-fill insulation material, kg/m2. If the solid material in the loose filling material is a non-porous material, the bulk density is the same as the density.
5.1.2 Packing density packingdensity
The bulk density of loose filling insulation materials in applications, kg/m. 5.2 Porosity (g) porosity
In porous media, the ratio of the total volume of internal pores to the total volume of the medium, %. It can be defined by the following formula: 5=[V/(V.+V.)]×100
Where; V. The volume of pores, m\,
V.-The volume of solids, m".
For a medium with a single solid matrix, the porosity GB/T4132--1996
g = (1 - [(pp)/(p - Pa)J) × 100 Where: p - material density, kg/m3, P - solid matrix density, kg/m3;
Pa - density of gas in pores, kg/m3. 5.3 Local porosity (s,) localporosity The porosity of point p in the micro region inside the object, %. 5.4 Drying linear shrinkage linearaldryingshrinkage The ratio of the length shrinkage value caused by the loss of water during the drying process to the original length, mm/m. 5.5 Maximum service temperature maximum service temperature The highest temperature that the material can withstand under the condition of ensuring normal use, K. 5.6 Average thermal expansion coefficient thermalexp ansioncoefficient The ratio of the increase in length or volume of a material for every 1K increase in temperature. It can be calculated as follows: β = (VV) / V, (TT))
= (L, L) / [L (T-T) J
In the formula: F - average volumetric thermal expansion coefficient, 1/K, T Www.bzxZ.net
material temperature before heating, K;
material temperature after heating, K;
material volume at T, m\,
V. material volume at T, m\
α - average linear thermal expansion coefficient, 1/K, L, material length at T, m;
material length at T, m.
5.7 Abrasion resistance reflects the performance of resistance to scratches, scrapes or wear.
5.8 Freeze-thaw resistance reflects the performance of materials to resist cyclic freezing and thawing. 5.9 Shape and dimensional stability shape and dimensional stability irreversible changes in the shape and size of materials under normal use conditions. 5.10 Impact resistance; toughness performance of resistance to mechanical collision or impact.
Transverse strength flexural strength 5.11
The breaking strength of the material under the load perpendicular to the axis of the specimen, MPa. Synonyms flexural strength
. (1a)
(2)
(3)
5.12 Compressive strength compressing strength The maximum compressive stress borne by the material during the process of compressive failure. For insulating materials whose rigidity gradually increases with the increase of load, the compressive strength can be determined by the limit value of the strain, MPa. 5.13 Lateral tensile strength Tensile strength in the thickness direction of the material.
5.14 Adhesive strength adhesive strength 6
GB/T4132-1996
The maximum tensile stress that the dried thermal insulation coating bears during the process of peeling off from the substrate under the action of positive tension, kPa. 5.15 Handling property The ability of a material or product to withstand transportation and installation loads. 5.16 Aging ageing
The process in which the physical, mechanical and thermal properties of materials, products and systems slowly change over time and tend to stabilize. Notes
1 The aging of loose filling materials and low-density materials is manifested as material sedimentation, and the aging of closed-cell foam plastics is manifested as gas diffusion. 2 Aging is related to the environment or working conditions in which the materials, products and systems are located, and to their shape, size and outer sheath. 5.17 Aged value
The physical, mechanical or thermal property value of a material, product or system after being placed under known environmental conditions for a certain time interval. 5.18 Accelerated aged value The physical, mechanical or thermal property value of a material, product or system after accelerated aging at a certain time interval in a laboratory under simulated working conditions.
5.19 Design life designlife-time The duration during which the design performance of the installed material, product or system remains basically unchanged. 5.20 Basic set basic set
The arithmetic mean and standard deviation of the thermal performance values of the material measured under standard test conditions. 5.21 Declared value declaredvalue
The thermal performance value determined by the manufacturer based on the data measured at the standard temperature and actual thickness of the insulation material or product, taking into account a certain confidence level and the expected service life. 5.22 Design value designvalue
The thermal performance value of the insulation material selected during design under the typical working conditions of the building. 5.23 Declared thickness declared thickness The thickness declared by the manufacturer, at which the loose filling or coating material has the declared thermal performance value. 5.24 Nominal thickness nominalthickness The reference thickness when the insulation product indicates the deviation. 5.25 Water absorption waterabsorption
The percentage of water absorbed by the material in water. It can be expressed as mass water absorption or volume water absorption, %. Notes
1 The ratio of the mass of absorbed water to the dry mass of the material is called mass water absorption. 2 The ratio of the volume of absorbed water to the total volume of the material is called volume water absorption. 3 When the material reaches saturation, it is called saturated water absorption. 5.26 Moisture absorption moistureabsorptionwatervapourabsorption The mass of water vapor absorbed by the material in the ambient atmosphere is the percentage of the mass of the dry material, %. When in equilibrium with the environment, it is called equilibrium moisture [water] content.
6 Heat transfer and mass transfer
6.1 General concepts
6.1.1 Steady state steadystate
The state in which the values of the relevant parameters of the system do not change with time. 6.1.2 Nonsteady state nonsteady state The state in which the values of the relevant parameters of the system change with time. 6.1.2.1 Periodic state GB/T4132-1996
The values of the relevant parameters of the system are repeated at certain time intervals and are not affected by the initial state. 6.1.2.2 Transient state The values of the relevant parameters of the system gradually transition from the initial state to the stable state or periodic state. 6.1.3 Thermal conduction The process of heat transfer caused by the movement of particles inside an object caused by temperature difference. 6.1.4 Thermal convection The process of heat transfer caused by the relative displacement of various parts in a fluid. 6.1.5 Thermal radiation
The process of heat transfer caused by the surface of an object emitting electromagnetic waves due to the temperature of the object. The wavelength of thermal radiation is mainly between 0.1 and 100 μm.
6.1.6 Heat transfer heat transfer
The process of energy transfer caused by thermal conduction, thermal convection or thermal radiation, and their combined action. Heat transfer by radiation heat transfer by radiation 6.1.75
The heat exchanged between objects separated from each other (or different parts inside an object) through thermal radiation. According to different situations, it can be preceded by the following words: a) Total Total related to all wavelengths. b) spectral is related to a certain spectral width with a central wavelength of λ. Synonym: monochromatic. c) hemispherical is related to all directions of the surface. d) directional is propagating in a fixed direction at a certain solid angle. 6.1.8 mass transfer
mass transfer (especially moisture and air) through various mechanisms. 6.1.9 moisture
water in a material, including water in the gas phase, liquid phase or solid phase. 6.1.10 water vapor diffusion water vapor diffusion the movement of water vapor molecules that makes the water vapor content or water vapor partial pressure in a mixed gas tend to equilibrium under the condition of constant total pressure.
6.1.11 water vapor convection water vapor convection the migration of water vapor caused by the movement of the mixed gas due to the total pressure difference. 6.2 general physical quantities
6.2.1 heat quantity of heat (Q) heat quantity of heat, J. 6.2.2 Heat flow (@) heat flow rate, W. 6.2.3 Heat flux density (g) areal density of heat flow rate The heat flow per unit area perpendicular to the direction of heat flow, W/m2. q=/dA
Note: When "heat flux density" and "linear heat flux density" may be confused, "areal heat flux density" is used instead of "heat flux density". Linear heat flux density (g) lineal density of heat flow 6.2.4
Heat flux density per unit pipe length, W/m.
6.2.5 Thermal conductivity (>) thermal conductivity A physical indicator of the thermal conductivity of a material. Numerically equal to the heat flux divided by the negative temperature gradient, W/(m·K). =/gradT
6.2.6 Thermal resistance (r) thermal resistance Thermal resistance is the reciprocal of thermal conductivity, (m·K)/W. Defined as follows: 8
·（4）
（5）
·（6）)75
The heat exchanged between separated objects (or different parts inside an object) through thermal radiation. Depending on the situation, it can be preceded by the following words: a) total, related to all wavelengths. b) spectral, related to a certain spectral width with a central wavelength of λ. Synonym: monochromatic. c) hemispherical, related to all directions on the surface. d) directional, propagating in a fixed direction at a certain solid angle. 6.1.8 mass transfer
Mass transfer (especially moisture and air) through various mechanisms. 6.1.9 moisture
Water in a material, including water in the gas phase, liquid phase or solid phase. 6.1.10 water vapor diffusion, water vapor diffusion, the movement of water vapor molecules that makes the water vapor content or water vapor partial pressure in a mixed gas tend to equilibrium under the condition of constant total pressure.
6.1.11 Water vapor convection water vapor convection The migration of water vapor caused by the movement of mixed gases due to the total pressure difference. 6.2 General physical quantities
6.2.1 Heat quantity of heat (Q) heat quantity of heat, J. 6.2.2 Heat flow (@) heat flow rate, W. 6.2.3 Heat flux density (g) areal density of heat flow rate The heat flow per unit area perpendicular to the direction of heat flow, W/m2. q=/dA
Note: When "heat flux density" and "linear heat flux density" may be confused, "areal heat flux density" is used instead of "heat flux density". Linear heat flux density (g) lineal density of heat flow 6.2.4
Heat flux density per unit pipe length, W/m.
6.2.5 Thermal conductivity (>) thermal conductivity A physical indicator of the thermal conductivity of a material. Numerically, it is equal to the heat flux divided by the negative temperature gradient, W/(m·K). =/gradT
6.2.6 Thermal resistance coefficient (r) Thermal resistance coefficient is the reciprocal of thermal conductivity, (m·K)/W. It is defined as follows: 8
·（4）
（5）
·（6）)75
The heat exchanged between separated objects (or different parts inside an object) through thermal radiation. Depending on the situation, it can be preceded by the following words: a) total, related to all wavelengths. b) spectral, related to a certain spectral width with a central wavelength of λ. Synonym: monochromatic. c) hemispherical, related to all directions on the surface. d) directional, propagating in a fixed direction at a certain solid angle. 6.1.8 mass transfer
Mass transfer (especially moisture and air) through various mechanisms. 6.1.9 moisture
Water in a material, including water in the gas phase, liquid phase or solid phase. 6.1.10 water vapor diffusion, water vapor diffusion, the movement of water vapor molecules that makes the water vapor content or water vapor partial pressure in a mixed gas tend to equilibrium under the condition of constant total pressure.
6.1.11 Water vapor convection water vapor convection The migration of water vapor caused by the movement of mixed gases due to the total pressure difference. 6.2 General physical quantities
6.2.1 Heat quantity of heat (Q) heat quantity of heat, J. 6.2.2 Heat flow (@) heat flow rate, W. 6.2.3 Heat flux density (g) areal density of heat flow rate The heat flow per unit area perpendicular to the direction of heat flow, W/m2. q=/dA
Note: When "heat flux density" and "linear heat flux density" may be confused, "areal heat flux density" is used instead of "heat flux density". Linear heat flux density (g) lineal density of heat flow 6.2.4
Heat flux density per unit pipe length, W/m.
6.2.5 Thermal conductivity (>) thermal conductivity A physical indicator of the thermal conductivity of a material. Numerically, it is equal to the heat flux divided by the negative temperature gradient, W/(m·K). =/gradT
6.2.6 Thermal resistance coefficient (r) Thermal resistance coefficient is the reciprocal of thermal conductivity, (m·K)/W. It is defined as follows: 8
·（4）
（5）
·（6）)
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