CN103114661A - Anti-condensation outer insulative wall body structure - Google Patents

Abstract

The invention discloses an anti-condensation outer insulative wall body structure and belongs to the technical field of wall body structures. The structure is characterized in that an inside air layer (9) and a water-steam-preventing layer (8) are sequentially arranged between an inner decorative plate (10) and a base layer load-bearing wall body (7); inner layer through holes (11) are arranged both on the upper portion and the lower portion of the inner decorative plate (10), and the inner layer through hole on the upper portion is connected with a wind-returning opening (14) are to ensure that negative pressure is formed by the inside air layer (9), and that cross-ventilation is formed between the inside air layer (9) and an interior of a room; a water diffusion layer (4), a water-proof layer (5) and an outside air layer (2) are sequentially arranged between an inflaming-retarding-type insulative material layer (5) and an outer decorative plate (1); and outer layer through holes (13) for the outside air layer (2) and the outside of a room to be communicated and form cross ventilation are arranged both above and below the outer decorative plate (1). The anti-condensation outer insulative wall body structure is obvious in level and structure, has good insulative, energy-saving, moisture-permeable and damp-proof performance, and can radically overcome critical defects that the inside of a building wall body is easy to be affected with damp, condensate, mildewed and airtight.

Description

Condensation-proof external thermal insulated wall body structure

Affiliated technical field

The present invention relates to a kind of external thermal insulated wall body structure, particularly a kind of not moisture-sensitive condensation, have the external thermal insulated wall body structure of excellent air permeability.

Background technology

In 2l century, energy shortage is still restricting the sustainable development of society, for completing Eleventh Five-Year Plan and perspective long-term plan in 2015, carries out thermal insulation at architectural employing heat insulating material, is the most effective power save mode, and its effect is also the most significant.At present, external wall outer insulation is the measure of the raising buildings exterior-protected structure thermal insulation widelyd popularize of the Ministry of Construction.But the area more than southern high humidity, rainwater, especially in the winter time use the building of air-conditioning, for on the general wall of energy efficient or there is no the ventilation setting on window, in case the structural configuration of heat-preserving energy-saving wall is unreasonable, the Living Water steam that indoor generation is a large amount of or the rainwater of outdoor infiltration and hygroscopic water can and be gathered by the body of wall absorbed inside, will cause in the winter time the condensation of body of wall internal wetted, cause wet accumulation excessive, increase body of wall and pass humidity load, thereby increase the thermal transmittance of whole body of wall, make annual energy consumption increase rapidly.Simultaneously the inside and outside surface of body of wall be prone to the larger area blackspot, become mildewed, the phenomenon such as mouldy, because these moulds form pollutant for a long time under wet environment, thereby IAQ (indoor air quality) is caused harmful effect, not only affect people's life comfort level, have a strong impact on again the structural strength of building integral, reduce its application life.

Summary of the invention

The objective of the invention is for addressing the above problem, a kind of novel outer insulation construction body of wall is provided, fundamentally overcome the inner moisture-sensitive condensation of construction wall, go mouldy, air-locked critical defect, can comprehensive ground, breakthrough the properties of heat preservation and energy saving of buildings exterior-protected structure and the comfort level of indoor inhabitation of improving.

Technical scheme of the present invention is as follows: by indoor to outdoor trim panel, basic unit's bearing wall, flame retardant type adiabator layer, the outer plaque of comprising, it is characterized in that: be provided with successively inboard air layer, steam barrier layer between above-mentioned trim panel and basic unit's bearing wall, and trim panel is equipped with the internal layer through hole up and down, utilize the return air inlet of air-conditioning to make inboard air layer form negative pressure, allow inboard air layer and indoor formation cross-ventilation; Be provided with successively moisture diffusion layer, waterproofing course, outside air layer between above-mentioned flame retardant type adiabator layer and outer plaque, and outer plaque is equipped with up and down and makes outside air layer and outdoor UNICOM form cross-ventilated outer through hole.

Beneficial effect of the present invention: have air layer and outer plaque to have up and down oblique lower aperture between outer plaque and heat insulating material, purpose allows and reaches fast pressure balance inside and outside heat-insulation system, can reduce outdoor because pressure reduction infiltrates intrasystem rainwater in rainy season, outer space gas-bearing formation and outdoor UNICOM form convection current, reduce steam and invade retaining wall, and a small amount of rainwater that infiltrates is discharged by the lower hole of outer plaque.The air coefficient of thermal conductivity is less, can reduce the temperature gradient in the insulation layer outside, thereby reduces the thermal stress due to violent variations in temperature generation.The moisture diffusion layer in the heat insulating material outside has the moisture adsorption and releasing function, when the adiabator layer hygroscopic water is excessive, lower partial vapor pressure is arranged in the moisture diffusion layer, and the wet of heat-insulation system outwards moved, and reaches wet effect; The moisture diffusion layer covers one deck waterproofing course outward again, because waterproofing course allows the hygroscopic water migration but do not allow aqueous water to pass through, so can well play waterproof action in rainwater infiltration situation.Trim panel leaves air layer with basic unit's bearing wall and in the middle of indoor separating, trim panel has the hole up and down, the place, hole utilizes the mechanical system exhausting to force air layer is formed negative pressure on trim panel, indoor environment is malleation, makes so inboard air layer form convection current, reduces hygroscopic water and enters basic unit's bearing wall, can also make in the winter time the hot blast of air-conditioning pass through air layer, heat is passed to wall, allow wall surface temperature higher than dewpoint temperature, be unlikely to the wall generation condensation of basic unit's bearing wall.The outer insulation construction body of wall water vapour permeability of the condensation-proof that the present invention proposes is better, can reduce hygroscopic water to the impact of thermal transmittance, thereby reaches the purpose that reduces energy consumption.Owing to effectively having prevented the wet accumulation in the outer heat preservation system, the outer insulation construction of this condensation-proof also is applicable to multiple climatological region, has solved the impact because of the bad durability on outer heat preservation system of poisture-penetrability in heat-insulation system, structural strength and heat-insulating property.

Trim panel can use gypsum plank, utilize to be bolted on basic unit's bearing wall, and the fixture gap utilizes encapsulant to seal, and prevents from that steam from contacting with bolt to cause corrosion.The steam barrier layer can adopt polyethylene sheeting, PE film, these two kinds of films can stop a large amount of Living Water steams of indoor generation to enter base course wall, and especially polyethylene sheeting can stop at the issuable liquid condensed water of base course wall indoor side surface and enters.

The flame retardant type adiabator layer can be inorganic heat insulation material such as glass wool etc., between it and basic unit's bearing wall, adopt adhesive stick at leveling layer and fix with fixture, the fixture gap utilizes encapsulant to seal, sorrow due to frozen-free in insulation layer, the stable in properties of heat insulating material can not cause transformation because of the wet accumulation in heat insulating material.

The moisture diffusion layer is veneer or oriented wood chipboard.Veneer has the moisture adsorption and releasing ability, therefore posts veneer outside insulation layer and reaches the damp proof effect of moisture absorption; Simultaneously, linear expansion coeffcient and the modulus of elasticity of moisture diffusion layer material and insulation layer material differ less, when system is subjected to warm and humid stress, have avoided traditional outer heat preservation system due to the poor excessive problem of Cracking that causes of adjacent materials rate of strain.

Waterproofing course is moistureproof paper or high polymer elastic coating material or polyethylene sheeting or bituminous waterproofing material.Wherein the high polymer elastic coating material can not only stop aqueous water to enter, can also allow vaporous water discharge, water vapor permeation coefficient satisfies under the prerequisite of standard in the system of assurance, the water absorption of reduction system and heat insulating material, make the sorrow of frozen-free in insulation layer, can effectively avoid cold, the humid area frost-heave force destruction to outer heat preservation system.

Outer plaque is fiber cement board or concrete slab or Decorative hanging board.Have weather resistance preferably, the assurance waterproofing course is brought into play its waterproof effect under better temperature, humidity environment, make waterproofing course avoid ultraviolet irradiation to delay the aging of waterproofing course.

The internal layer through hole is comprised of through hole on internal layer and internal layer lower through-hole; And the ratio of perforated area sum and trim panel area is more than or equal to 2%, and the ratio of perforated area sum and the volume of inboard air layer is more than or equal to 0.05 (1/m), be conducive to form effective convection current in air layer, strengthen protection against the tide and mould proof, certain sound insulation effect is arranged simultaneously.The upper limit of perforated area is advisable with the intensity that does not affect trim panel function and installation and do not weaken trim panel.

Outer through hole is comprised of upper through hole and lower through-hole, and opening direction is oblique lower mode from inside to outside, to prevent that rainwater from entering system, and the ratio of perforated area sum and outer plaque area is more than or equal to 2%, and the ratio of perforated area sum and the volume of outer space gas-bearing formation is more than or equal to 0.05 (1/m), be beneficial to outer space gas-bearing formation and outdoor UNICOM and form convection current, reduce steam and invade outer heat preservation system, and a small amount of rainwater that infiltrates can be discharged by the lower through-hole of outer plaque smoothly.The upper limit of perforated area is not to affect the outer plaque function and to install with the intensity that does not weaken outer plaque and be advisable.

Outside air layer and outdoor UNICOM, energy balance sysmte external and internal pressure stops extraneous moisture from entering system well.Because the air layer coefficient of thermal conductivity is less, equaling has increased one deck flexible transition layer in internal system, make the whole system flexible gradual change, heat successively transmits, moisture diffusion layer and adiabator layer can not make because inside has larger temperature gradient self temperature deformation poor larger yet like this, cause occuring bending and deformation.

The beneficial effect of inboard air layer and indoor formation cross-ventilation internal layer through hole: in the winter time after a large amount of living water use steam of indoor generation, the air of inboard air layer and room air produce convection current, the hygroscopic water of air layer is taken away and is entered the return air inlet of air-conditioning, reduced the wet accumulation of body of wall inside, greatly reduce the condensation rate of basic unit's bearing wall, thereby play the wet effect of thermal insulation separation.

The interior outside desirable thickness range of air layer in Different climate area has larger difference, take Beijing, Harbin, city, three, Nanjing is example, by the design standard for energy efficiency of buildings requirement, the interior outside desirable thickness range of air layer that gets as calculated these three cities is respectively 18-30mm, 25-60mm, 10-25mm.。

Description of drawings

Fig. 1: condensation-proof external heat insulating wall structural representation;

Fig. 2: the condensation-proof external heat insulating wall is by the front view of indoor;

Fig. 3: the condensation-proof external heat insulating wall is by the front view of outside;

Fig. 4: internal node is processed schematic diagram;

Fig. 5: indoor BORDER PROCESSING schematic diagram;

Fig. 6: outside BORDER PROCESSING schematic diagram;

Fig. 7: the wall heat transfer coefficient of the different air layer thicknesses in Beijing area;

Fig. 8: the wall heat transfer coefficient of the different air layer thicknesses of Border in Harbin Area;

Fig. 9: the wall heat transfer coefficient of the different air layer thicknesses of In Nanjing;

Number in the figure title: 1. outer plaque, 2. outside air layer, 3. waterproofing course, 4. moisture diffusion layer, 5. flame retardant type adiabator layer, 6. cement mortar screeding layer, 7. basic unit's bearing wall, 8. steam barrier layer, 9. inboard air layer, 10. trim panel, 11. internal layer through hole, 12. fixture, 13. outer through holes, 14. return air inlets.

The specific embodiment

1, embodiment: Fig. 1 is external heat insulating wall structural representation of the present invention, as shown in Figure 1, be followed successively by from outside to inside cement board 1, outside air layer 2, high polymer elastic coating material 3, veneer 4, flame retardant type heat insulating material 5, cement mortar screeding 6, basic unit's bearing wall 7, polyethylene sheeting 8, inboard air layer 9, gypsum plank 10.

The sum of perforated area up and down of gypsum plank is not less than 0.05 (1/m) with the ratio of inboard air layer volume, the thickness of air layer is between 10mm～60mm, get 20mm, the cleaning basal plane, being close to the layer of polyethylene film at basic unit's bearing wall by the indoor does waterproof and uses and fix, then by bolt 12, gypsum plank is fixed on basic unit's bearing wall, the fixed interval (FI) must seal with encapsulant, and the fixture spacing is 200mm.Use the 1:3 cement mortar screeding between flame retardant type heat insulating material and basic unit's bearing wall, the flame retardant type heat insulating material is fixed on basic unit's bearing wall by the outside by adhesive, heat insulating material covers one deck veneer outward, one deck high polymer elastic coating material is covered again as waterproofing course in the veneer outside, prevents a small amount of rainwater intrusion heat insulating material that infiltrates.By fixture crab-bolt 12 fixtures, flame retardant type heat insulating material, veneer and high polymer elastic coating material are fixed on basic unit's bearing wall, the gap utilizes encapsulant to seal, and the fixture spacing is 200mm.

The body of wall outermost uses cement board, boring and mounting fixing parts, gap place's packing closure material.Because the outer plaque of the outer insulation construction of tradition is to be close on heat insulating material, easily under the effect of blast, make rainwater pass surface gaps or the fixture space squirts heat insulating material or handing-over seam, enter subsequently body of wall inside under the pressure differential effect, so outer plaque has outer through hole 13 up and down now, by the air layer between outer plaque and waterproofing course, with outdoor mineralization pressure balance, reduce outside hygroscopic water and penetrate into body of wall inside, and a small amount of rainwater that infiltrates can be discharged by following outer through hole 13.

2, calculation of parameter example

(1) the external heat insulating wall heat transfer passes wet Mathematical Modeling

Construction wall height and width are supposed wet the transmission only along the thickness of wall body direction of heat under the poor effect of indoor/outdoor temperature-difference and water vapour pressure much larger than thickness, and hypothesis:

A. material isotropism;

B. there is not the liquid flow of macroscopic view in material;

C. material thermal conductivity is the function of temperature and total water capacity;

D. each is in thermal equilibrium state mutually;

E. do not consider the evaporation latent heat at the inside and outside wall of body of wall place;

F. do not consider that warm and humid gradient is on the impact of the wet balance in wall place inside and outside body of wall.

Energy and the mass-conservation equation formula about every layer of porous material be respectively [Su Xianghui. heat wet coupling migrate attribute research [D] in architectural exterior-protecting construction. Nanjing: Nanjing Aero-Space University, 2002. (p29)]:

${\mathrm{\ρc}}_p\frac{\∂T}{\∂t}=\frac{\∂}{\∂x}\left(\mathrm{\λ}(x,t)\frac{\∂T}{\∂x}\right)+h_{\mathrm{lv}}\mathrm{\Γ}(x,t)---\left(1\right)$

$\frac{{\∂\mathrm{\ρ}}_v}{\∂t}+\frac{\mathrm{\Γ}(x,t)}{\mathrm{\ϵ}}=\frac{\∂}{\∂x}\left(D_v(x,t)\frac{{\∂\mathrm{\ρ}}_v}{\∂x}\right)---\left(2\right)$

Fringe conditions:

$\mathrm{\λ}(x,t)\·\frac{\∂T}{\∂x}{|}_{x=0}={\mathrm{\α}}_{\mathrm{in}}(T_0-T_{\mathrm{in}})---\left(3\right)$

$\mathrm{\λ}(x,t)\·\frac{\∂T}{\∂x}{|}_{x=N}={\mathrm{\α}}_{\mathrm{out}}(T_{\mathrm{out}}-T_N)---\left(4\right)$

$D_a\mathrm{\ϵ}\·\frac{{\∂\mathrm{\ρ}}_v}{\∂x}{|}_{x=0}={\mathrm{\β}}_{\mathrm{in}}({\mathrm{\ρ}}_{v0}-{\mathrm{\ρ}}_{\mathrm{vin}})/{\mathrm{\ρ}}_{v0}---\left(5\right)$

$D_a\mathrm{\ϵ}\·\frac{{\∂\mathrm{\ρ}}_v}{\∂x}{|}_{x=N}={\mathrm{\β}}_{\mathrm{out}}({\mathrm{\ρ}}_{\mathrm{vout}}-{\mathrm{\ρ}}_{\mathrm{vN}})/{\mathrm{\ρ}}_{\mathrm{vN}}---\left(6\right)$

Primary condition:

T (x, 0)=T _b, ρ _v(x, 0)=ρ _vb(7) in formula, T is temperature (K), and t is time (s), and x is coordinate, λ=λ _dry+ 0.6U, λ _dryCoefficient of thermal conductivity (W/ (mK)) during for the material drying, U is total water capacity (kg/kg) of material, c _pBe the specific heat (J/ (kgK)) of material, ρ is the density (kg/m of material ³), h _lvBe evaporation latent heat (J/kg), Г is wet accumulation rate (kg/ (m ³S)), ρ _vBe water-vapour density (kg/m ³), ε is the degree of porosity (m of material ³/ m ³), α is convection transfer rate (W/ (m ²K)), β is the wet exchange coefficient (kg/ (m of convection current ²S)), β=α/c _p,, D _vBe the water vapor diffusion coefficient (m in material ²/ s),

[H.M.K ü nzel.Simultaneous heat and moisture transport in building components one-two-dimensional calculation using simple parameters[R] .IRB Verlag, Stuttgart.1995. (15)], D _aBe airborne water vapor diffusion Coefficient m ²/ s, D _a=D _vμ, μ are the water vapor diffusion resistance coefficient (zero dimension) of material, R _vBe the gas constant J/ (kgK) of steam,

Subscript: O, N refer to respectively indoor, outdoor border; In and out refer to respectively indoor and outdoor surroundings; B refers to initial value.

(2) wet accumulation rate is determined

Frozen-free in material, wet accumulation is determined by following formula:

Order:

$\mathrm{\Γ}(x,t)=f_T\·\frac{\∂T}{\∂t}+f_W\·\frac{{\∂\mathrm{\ρ}}_v}{\∂t}---\left(9\right)$

Condensation occurs in material, be in equilibrium state at condensing zone liquid and steam, water vapor concentration reaches capacity, and water vapor concentration is counted ρ only by the temperature decision _vFor

That is:

${\mathrm{\ρ}}_v^{*}(x,t)=216.5\×P\left(T(x,t)\right)\×{10}^{-5}/T(x,t)---\left(10\right)$

Wet accumulation this moment is unique to be determined by the matter equilibrium equation:

$\mathrm{\Γ}(x,t)=\mathrm{\ϵ}\·(D_v\·\frac{{\∂}^2{\mathrm{\ρ}}_v^{*}}{{\∂x}^2}-\frac{\∂{\mathrm{\ρ}}_v^{*}}{\∂t})=\mathrm{\ϵ}\·(D_v\·\frac{{\∂\mathrm{\ρ}}_v^{*}}{\∂T}\·\frac{{\∂}^{2}T}{{\∂x}^2}-\frac{{\∂\mathrm{\ρ}}_v^{*}}{\∂T}\frac{\∂T}{\∂t})---\left(11\right)$

The water capacity of material:

$U(x,t)=\frac{1}{\mathrm{\ρ}}{\∫}_0^t\mathrm{\Γ}(x,t)\mathrm{dt}---\left(12\right)$

(3) Finite Volume Method for Air is found the solution the wet coupled wave equation of heat

With Г (x, t) the substitution full scale equation (1) of frozen-free in material, (2), energy and mass-conservation equation are following form:

$f_T\frac{\∂T}{\∂t}+(\mathrm{\ϵ}+f_W)\frac{{\∂\mathrm{\ρ}}_v}{\∂t}=D_v\mathrm{\ϵ}\frac{{\∂}^2{\mathrm{\ρ}}_v}{{\∂x}^2}---\left(13\right)$

$({\mathrm{\ρc}}_p-f_T{h}_{\mathrm{lv}})\frac{\∂T}{\∂t}-h_{\mathrm{lv}}{f}_W\frac{{\∂\mathrm{\ρ}}_v}{\∂t}=\mathrm{\λ}\frac{{\∂}^{2}T}{{\∂x}^2}---\left(14\right)$

To occur Г (x, t) the substitution full scale equation (1) of condensation in material, (2) can get:

${\mathrm{\ρc}}_p\frac{\∂T}{\∂t}=\mathrm{\λ}\frac{{\∂}^{2}T}{{\∂x}^2}+h_{\mathrm{lv}}\mathrm{\ϵ}(D_v\·\frac{{\∂\mathrm{\ρ}}_v^{*}}{\∂T}\·\frac{{\∂}^{2}T}{{\∂x}^2}-\frac{{\∂\mathrm{\ρ}}_v^{*}}{\∂T}\·\frac{\∂T}{\∂t})---\left(15\right)$

General formula can be write as in equation (13)-(15):

$A\frac{\∂T}{\∂t}+B\frac{{\∂\mathrm{\ρ}}_v}{\∂t}=\frac{{\∂}^2{\mathrm{\ρ}}_v}{{\∂x}^2}---\left(16\right)$

$C\frac{\∂T}{\∂t}+D\frac{{\∂\mathrm{\ρ}}_v}{\∂t}=\frac{{\∂}^{2}T}{{\∂x}^2}---\left(17\right)$

When the coefficient during frozen-free in material: $A=\frac{f_T}{D_v\mathrm{\ϵ}};$ $B=\frac{f_W+\mathrm{\ϵ}}{D_v\mathrm{\ϵ}};$ $C=\frac{{\mathrm{\ρc}}_p-f_T{h}_{\mathrm{lv}}}{\mathrm{\λ}};$ $D=-\frac{h_{\mathrm{lv}}{f}_W}{\mathrm{\λ}}$

Coefficient when condensation occurring in material: A=B=D=0;

$C=({\mathrm{\ρc}}_p+h_{\mathrm{lv}}\mathrm{\ϵ}\frac{{\∂\mathrm{\ρ}}_v^{*}}{\∂T})/(\mathrm{\λ}+h_{\mathrm{lv}}\mathrm{\ϵ}{D}_v\frac{{\∂\mathrm{\ρ}}_v^{*}}{\∂T})$

A. internal node is carried out integration:

To equation (16) carry out in dxdt integration [inscription on pottery select work. numerical heat transfer [M]. Xi'an: publishing house of Xi'an Communications University, 2001, (28 ~ 43)]: internal node is processed as shown in Figure 4:

${\∫}_w^e{\∫}_t^{t+\mathrm{dt}}A\frac{\∂T}{\∂t}\mathrm{dtdx}+{\∫}_w^e{\∫}_t^{t+\mathrm{dt}}B\frac{{\∂\mathrm{\ρ}}_v}{\∂t}\mathrm{dtdx}={\∫}_t^{t+\mathrm{dt}}{\∫}_w^e\frac{{\∂}^2{\mathrm{\ρ}}_v}{{\∂x}^2}\mathrm{dxdt}---\left(18\right)$

That is:

$\mathrm{A\Δx}(T_p-T_p^0)+\mathrm{B\Δx}({\left({\mathrm{\ρ}}_v\right)}_P-{\left({\mathrm{\ρ}}_v\right)}_P^0)=\mathrm{\Δt}(\frac{{\∂\mathrm{\ρ}}_v}{\∂x}{|}_e-\frac{{\∂\mathrm{\ρ}}_v}{\∂x}{|}_w)---\left(19\right)$

That is:

$\mathrm{A\Δx}(T_p-T_p^0)+\mathrm{B\Δx}({\left({\mathrm{\ρ}}_v\right)}_P-{\left({\mathrm{\ρ}}_v\right)}_P^0)=\mathrm{\Δt}[\frac{{\left({\mathrm{\ρ}}_v\right)}_E-{\left({\mathrm{\ρ}}_v\right)}_P}{{\left(\mathrm{\δx}\right)}_e}-\frac{{\left({\mathrm{\ρ}}_v\right)}_P-{\left({\mathrm{\ρ}}_v\right)}_W}{{\left(\mathrm{\δx}\right)}_w}]---\left(20\right)$

Order $a_E=\frac{1}{{\left(\mathrm{\δx}\right)}_e},$ $a_W=\frac{1}{{\left(\mathrm{\δx}\right)}_w}.$ So

$\frac{\mathrm{A\Δx}}{\mathrm{\Δt}}(T_p-T_p^0)+\frac{\mathrm{B\Δx}}{\mathrm{\Δt}}({\left({\mathrm{\ρ}}_v\right)}_P-{\left({\mathrm{\ρ}}_v\right)}_p^0)={\mathrm{\α}}_E{\left({\mathrm{\ρ}}_v\right)}_E-(a_E+a_W){\left({\mathrm{\ρ}}_v\right)}_P+a_W{\left({\mathrm{\ρ}}_v\right)}_W---\left(21\right)$

In like manner, equation (17) is also at dx, and in dt, integration can obtain:

$\frac{\mathrm{C\Δx}}{\mathrm{\Δt}}(T_p-T_p^0)+\frac{\mathrm{D\Δx}}{\mathrm{\Δt}}({\left({\mathrm{\ρ}}_v\right)}_p-{\left({\mathrm{\ρ}}_v\right)}_p^0)={\mathrm{\α}}_E{T}_E-(a_E+a_W)T_P+a_W{T}_W---\left(22\right)$

Obtain through arrangement:

$\frac{\mathrm{A\&Delta;x}}{\mathrm{\&Delta;t}}\&CenterDot;T_P-a_E{\left({\mathrm{\&rho;}}_v\right)}_E+(a_E+a_W+\frac{\mathrm{B\&Delta;x}}{\mathrm{\&Delta;t}})\&CenterDot;{\left({\mathrm{\&rho;}}_v\right)}_P-a_W{\left({\mathrm{\&rho;}}_v\right)}_W=\frac{\mathrm{A\&Delta;x}}{\mathrm{\&Delta;t}}\&CenterDot;{\mathrm{<figure-callout\; id="0"\; label="T\; P"\; filenames="130122135848.png"\; state="\{\{state\}\}">T</figure-callout>}}_P^{}+\frac{\mathrm{B\&Delta;x}}{\mathrm{\&Delta;t}}\&CenterDot;{\left({\mathrm{\&rho;}}_v\right)}_P^0---\left(23\right)$

$\frac{\mathrm{D\&Delta;x}}{\mathrm{\&Delta;t}}\&CenterDot;{\left({\mathrm{\&rho;}}_v\right)}_P-a_E{T}_E+(a_E+a_W+\frac{\mathrm{C\&Delta;x}}{\mathrm{\&Delta;t}})\&CenterDot;T_P-a_W{T}_W=\frac{\mathrm{C\&Delta;x}}{\mathrm{\&Delta;t}}\&CenterDot;{\mathrm{<figure-callout\; id="0"\; label="T\; P"\; filenames="130122135848.png"\; state="\{\{state\}\}">T</figure-callout>}}_P^{}+\frac{\mathrm{D\&Delta;x}}{\mathrm{\&Delta;t}}\&CenterDot;{\left({\mathrm{\&rho;}}_v\right)}_P^0---\left(24\right)$

B. temperature boundary is processed

Boundary node is processed as shown in Figure 5: internal boundary condition formula (3) can be treated to following form:

$\frac{T_{\mathrm{PI}}-T_{\mathrm{WI}}}{0.5\mathrm{\&Delta;x}}=\frac{{\mathrm{\&alpha;}}_{\mathrm{in}}}{\mathrm{\&lambda;}}(T_{\mathrm{WI}}-T_{\mathrm{in}})---\left(25\right)$

That is:

$T_{\mathrm{WI}}=\frac{\mathrm{\&lambda;}}{\mathrm{\&lambda;}+0.5\mathrm{\&Delta;x}\&CenterDot;{\mathrm{\&alpha;}}_{\mathrm{in}}}\&CenterDot;T_{\mathrm{PI}}+\frac{0.5\mathrm{\&Delta;x}{\mathrm{\&alpha;}}_{\mathrm{in}}}{\mathrm{\&lambda;}+0.5\mathrm{\&Delta;x}{\mathrm{\&alpha;}}_{\mathrm{in}}}\&CenterDot;T_{\mathrm{in}}---\left(26\right)$

In like manner can obtain the external boundary node processing as shown in Figure 6:

$T_{\mathrm{EO}}=\frac{\mathrm{\&lambda;}}{\mathrm{\&lambda;}+0.5\mathrm{\&Delta;x}\&CenterDot;{\mathrm{\&alpha;}}_{\mathrm{out}}}\&CenterDot;T_{\mathrm{PO}}+\frac{0.5\mathrm{\&Delta;x}{\mathrm{\&alpha;}}_{\mathrm{out}}}{\mathrm{\&lambda;}+0.5\mathrm{\&Delta;x}{\mathrm{\&alpha;}}_{\mathrm{out}}}\&CenterDot;T_{\mathrm{out}}---\left(27\right)$

Order $k_3=\frac{\mathrm{\&lambda;}}{\mathrm{\&lambda;}+0.5\mathrm{\&Delta;x}\&CenterDot;{\mathrm{\&alpha;}}_{\mathrm{in}}},$ $k_4=\frac{0.5\mathrm{\&Delta;x}\&CenterDot;{\mathrm{\&alpha;}}_{\mathrm{in}}}{\mathrm{\&lambda;}+0.5\mathrm{\&Delta;x}\&CenterDot;{\mathrm{\&alpha;}}_{\mathrm{in}}},$ $m_3=\frac{\mathrm{\&lambda;}}{\mathrm{\&lambda;}+0.5\mathrm{\&Delta;x}\&CenterDot;{\mathrm{\&alpha;}}_{\mathrm{out}}},$ $m_4=\frac{0.5\mathrm{\&Delta;x}\&CenterDot;{\mathrm{\&alpha;}}_{\mathrm{out}}}{\mathrm{\&lambda;}+0.5\mathrm{\&Delta;x}\&CenterDot;{\mathrm{\&alpha;}}_{\mathrm{out}}}$

Formula (26) and formula (27) can be write as following form:

T _WI=k ₃T _PI+k ₄T _in （28）

T _EO＝m ₃T _PO+m ₄T _out （29）

C. humidity BORDER PROCESSING

Border conditional (5) and (6) are carried out above-mentioned identical boundary nodal method:

Inner boundary:

$\frac{{\left({\mathrm{\&rho;}}_v\right)}_{\mathrm{PI}}-{\left({\mathrm{\&rho;}}_v\right)}_{\mathrm{WI}}}{0.5\mathrm{\&Delta;x}}=\frac{{\mathrm{\&beta;}}_{\mathrm{in}}}{\mathrm{\&rho;}{D}_a\mathrm{\&epsiv;}}({\left({\mathrm{\&rho;}}_v\right)}_{\mathrm{WI}}-{\left({\mathrm{\&rho;}}_v\right)}_{\mathrm{in}})---\left(30\right)$

That is:

${\left({\mathrm{\&rho;}}_v\right)}_{\mathrm{WI}}={\left({\mathrm{\&rho;}}_v\right)}_{\mathrm{PI}}-\frac{0.5\mathrm{\&Delta;x}\&CenterDot;({\left({\mathrm{\&rho;}}_v\right)}_{\mathrm{PI}}-{\left({\mathrm{\&rho;}}_v\right)}_{\mathrm{in}})}{0.5\mathrm{\&Delta;x}+\frac{\mathrm{\&rho;}{D}_a\mathrm{\&epsiv;}}{{\mathrm{\&beta;}}_{\mathrm{in}}}}---\left(31\right)$

External boundary:

${\left({\mathrm{\&rho;}}_v\right)}_{\mathrm{EO}}={\left({\mathrm{\&rho;}}_v\right)}_{\mathrm{PO}}-\frac{0.5\mathrm{\&Delta;x}\&CenterDot;({\left({\mathrm{\&rho;}}_N\right)}_{\mathrm{PO}}-{\left({\mathrm{\&rho;}}_v\right)}_{\mathrm{out}})}{0.5\mathrm{\&Delta;x}+\frac{\mathrm{\&rho;}{D}_a\mathrm{\&epsiv;}}{{\mathrm{\&beta;}}_{\mathrm{out}}}}---\left(32\right)$

Order $k_1=\frac{\mathrm{\&rho;}{D}_a\mathrm{\&epsiv;}}{0.5\mathrm{\&Delta;x}\&CenterDot;{\mathrm{\&beta;}}_{\mathrm{in}}+\mathrm{\&rho;}{D}_a\mathrm{\&epsiv;}},$ $k_2=\frac{0.5\mathrm{\&Delta;x}\&CenterDot;{\mathrm{\&beta;}}_{\mathrm{in}}}{0.5\mathrm{\&Delta;x}\&CenterDot;{\mathrm{\&beta;}}_{\mathrm{in}}+\mathrm{\&rho;}{D}_a\mathrm{\&epsiv;}},$

$m_1=\frac{\mathrm{\&rho;}{D}_a\mathrm{\&epsiv;}}{0.5\mathrm{\&Delta;x}\&CenterDot;{\mathrm{\&beta;}}_{\mathrm{out}}+\mathrm{\&rho;}{D}_a\mathrm{\&epsiv;}},$ $m_2=\frac{0.5\mathrm{\&Delta;x}\&CenterDot;{\mathrm{\&beta;}}_{\mathrm{out}}}{0.5\mathrm{\&Delta;x}\&CenterDot;{\mathrm{\&beta;}}_{\mathrm{out}}+\mathrm{\&rho;}{D}_a\mathrm{\&epsiv;}}$

Formula (31) and formula (32) can be write as following form:

(ρ _v) _WI＝k ₁(ρ _v) _PI+k ₂(ρ _v) _in （33）

(ρ _v) _EO＝m ₁(ρ _v) _PO+m ₂(ρ _v) _out （34）

For the equation form of the control volume at adjacent inner and outer boundary place, due to the unknown parameters of boundary, be to eliminate unknown quantity T _WI, (ρ _v) _WIAnd T _EO, (ρ _v) _EO, with formula (28), (29), (33), (34) substitution governing equation (23)-(24) separately respectively, obtain the equation form that is affected by the outside air parameter:

$\frac{\mathrm{A\&Delta;x}}{\mathrm{\&Delta;t}}\&CenterDot;T_{\mathrm{PI}}-a_E{\left({\mathrm{\&rho;}}_v\right)}_{\mathrm{EI}}+(a_E+a_W+\frac{\mathrm{B\&Delta;x}}{\mathrm{\&Delta;t}}-a_W{k}_1)\&CenterDot;{\left({\mathrm{\&rho;}}_v\right)}_{\mathrm{PI}}-a_W{k}_2{\left({\mathrm{\&rho;}}_v\right)}_{\mathrm{in}}=\frac{\mathrm{A\&Delta;x}}{\mathrm{\&Delta;t}}\&CenterDot;{\mathrm{<figure-callout\; id="0"\; label="T\; PI"\; filenames="130122135848.png"\; state="\{\{state\}\}">T</figure-callout>}}_{\mathrm{PI}}^{}+\frac{\mathrm{B\&Delta;x}}{\mathrm{\&Delta;t}}\&CenterDot;{\left({\mathrm{\&rho;}}_v\right)}_{\mathrm{PI}}^0---(3$

$5)$

$\frac{\mathrm{D\&Delta;x}}{\mathrm{\&Delta;t}}\&CenterDot;{\left({\mathrm{\&rho;}}_v\right)}_{\mathrm{PI}}-a_E{T}_{\mathrm{EI}}+(a_E+a_W+\frac{\mathrm{C\&Delta;x}}{\mathrm{\&Delta;t}}-a_W{k}_3)\&CenterDot;T_{\mathrm{PI}}-a_W{k}_4{T}_{\mathrm{in}}=\frac{\mathrm{C\&Delta;x}}{\mathrm{\&Delta;t}}\&CenterDot;{\mathrm{<figure-callout\; id="0"\; label="T\; PI"\; filenames="130122135848.png"\; state="\{\{state\}\}">T</figure-callout>}}_{\mathrm{PI}}^{}+\frac{\mathrm{D\&Delta;x}}{\mathrm{\&Delta;t}}\&CenterDot;{\left({\mathrm{\&rho;}}_v\right)}_{\mathrm{PI}}^0---\left(36\right)$

$\frac{\mathrm{A\&Delta;x}}{\mathrm{\&Delta;t}}\&CenterDot;T_{\mathrm{PO}}+(a_E+a_W+\frac{\mathrm{B\&Delta;x}}{\mathrm{\&Delta;t}}-a_E{m}_1)\&CenterDot;{\left({\mathrm{\&rho;}}_v\right)}_{\mathrm{PO}}-a_W{\left({\mathrm{\&rho;}}_v\right)}_{\mathrm{WO}}-a_E{m}_2{\left({\mathrm{\&rho;}}_v\right)}_{\mathrm{out}}=\frac{\mathrm{A\&Delta;x}}{\mathrm{\&Delta;t}}\&CenterDot;{\mathrm{<figure-callout\; id="0"\; label="T\; PO"\; filenames="130122135848.png"\; state="\{\{state\}\}">T</figure-callout>}}_{\mathrm{PO}}^{}+\frac{\mathrm{B\&Delta;x}}{\mathrm{\&Delta;t}}\&CenterDot;{\left({\mathrm{\&rho;}}_v\right)}_{\mathrm{PO}}^0---\left(37\right)$

$\frac{\mathrm{D\&Delta;x}}{\mathrm{\&Delta;t}}\&CenterDot;{\left({\mathrm{\&rho;}}_v\right)}_{\mathrm{PO}}+(a_E+a_W+\frac{\mathrm{C\&Delta;x}}{\mathrm{\&Delta;t}}-a_E{m}_3)\&CenterDot;T_{\mathrm{PO}}-a_W{T}_{\mathrm{WO}}-a_E{m}_4{T}_{\mathrm{out}}=\frac{\mathrm{C\&Delta;x}}{\mathrm{\&Delta;t}}\&CenterDot;{\mathrm{<figure-callout\; id="0"\; label="T\; PO"\; filenames="130122135848.png"\; state="\{\{state\}\}">T</figure-callout>}}_{\mathrm{PO}}^{}+\frac{\mathrm{D\&Delta;x}}{\mathrm{\&Delta;t}}\&CenterDot;{\left({\mathrm{\&rho;}}_v\right)}_{\mathrm{PO}}^0---\left(38\right)$

Comprehensive above-mentioned formula (23)-(24), (35)-(38) can be write as:

Ma×T+Mb×ρ _v=T ₀ （39）

Maa×T+Mbb×ρ _v＝RH ₀ （40）

Wherein, Ma, Mb, Maa, Mbb, T ₀, RH ₀Matrix is all known constant matrices, and then can program and ask for thermal field and moisture field T, ρ _vAfter obtaining thermal field and moisture field, can obtain total water capacity U.Because the physical parameter of material temperature and the water capacity with material itself changes, therefore use constantly a physical parameter value and calculate next thermal field and moisture field and heat flow density constantly, and the physical parameter of new material more.To outside air layer thickness in each given structure, can calculate the Transient Heat Transfer COEFFICIENT K of structure according to the transient state temperature field that calculates and heat flow density, whether surpass given limit value in [GB50189-2005 " public building energy design standard " (6 ~ 8)] standard, the thickness range of Analysis deterrmination air layer by the value that judges Coefficient K.

(4) calculated examples

By China's Study on Climate Division standard, take Beijing, three comparatively typical climatological regions such as Harbin, Nanjing are as example, standard heat transfer [GB50189-2005 " public building energy design standard " (6 ~ 8)] according to various places, utilize following formula [Zhang Ximin. thermal conduction study (the 4th edition). Beijing: China Construction Industry Press, 2001(29)) to try to achieve under the outer insulation construction design conditions of tradition (material is dry state at this moment) limit value thickness when insulation layer is flame retardant type XPS plastic extrusion heated board as shown in table 1.

$K=1/(R_{\mathrm{in}}+R_{\mathrm{out}}+\underset{i=1}{\overset{i=n}{\mathrm{\&Sigma;}}}\frac{{\mathrm{\&delta;}}_i}{{\mathrm{\&lambda;}}_i})---\left(41\right)$

δ in formula _iThickness m for layers of material; λ _iCoefficient of thermal conductivity W/ (mK) for layers of material; R _inR _outBe respectively body of wall surfaces externally and internally heat convection thermal resistance, R _in=0.11 (m ²K)/W, R _out=0.05 (m ²K)/W.[GB50176-93 " code for thermal design of civil buildings " (subordinate list 2.2, subordinate list 2.3)]

Limit value thickness when table 1 various places heat insulating material uses XPS

Condensation in the outer insulation construction of the tradition structure that may cause because of the material moisture absorption under actual weather conditions under this limit value thickness, its thermal transmittance will increase sharply, standard heat transfer under the design conditions.The perforate air layer of condensation-proof structure of the present invention is conducive to prevent the appearance of above-mentioned unfavorable factor, to outside air layer thickness in each given structure, calculate the thermal transmittance of condensation-proof structure under actual weather conditions, whether surpass given limit value in [GB50189-2005 " public building energy design standard " (6 ~ 8)] standard, the thickness range of Analysis deterrmination air layer by the value that judges Coefficient K.

The material parameter of outer each layer of the insulation construction use of condensation-proof is as shown in table 2, the primary condition of calculating take respectively Beijing, Harbin, Nanjing outdoor meteorological data of typical meteorological year [the special-purpose meteorological dataset of Chinese architecture analysis of Thermal Environment. Beijing: China Construction Industry Press, 2005.(data in appended CD)], interior temperature is 20 ℃, and relative humidity is 50%, and each layer of body of wall initial temperature is 19 ℃, and moisture content is maximum 100Vol%, be 1 year computing time.Based on above-mentioned thermal transient wet coupling TRANSFER MODEL and the corresponding numerical method set up in outer insulation construction, coding carries out the numerical simulation of condensation-proof external thermal insulated wall body structure.Air layer thickness is respectively from 5mm～60mm value, and the heat transfer that calculates must satisfy the respective standard requirement on three ground, result such as Fig. 7～and shown in Figure 9, and the desirable scope of thickness of outside air layer in Beijing, Harbin, In Nanjing is listed in table 3.

The parameter of table 2 said structure layers of material

The desirable thickness range of interior outside air layer of table 3 each department

Claims (10)

1. condensation-proof external thermal insulated wall body structure, be is characterized in that to outdoor trim panel (10), basic unit's bearing wall (7), flame retardant type adiabator layer (5), the outer plaque (1) of comprising by indoor:

Be provided with successively inboard air layer (9), steam barrier layer (8) between above-mentioned trim panel (10) and basic unit's bearing wall (7), and trim panel (10) is equipped with internal layer through hole (11) up and down, the internal layer through hole (11) of top is connected with the return air inlet (14) of air-conditioning so that inboard air layer (9) formation negative pressure, allows inboard air layer (9) and indoor formation cross-ventilation;

Be provided with successively moisture diffusion layer (4), waterproofing course (3), outside air layer (2) between above-mentioned flame retardant type adiabator layer (5) and outer plaque (1), and outer plaque (1) is equipped with up and down and makes outside air layer (2) and outdoor UNICOM form cross-ventilated outer through hole (13).

2. condensation-proof external thermal insulated wall body structure according to claim 1, it is characterized in that: above-mentioned trim panel (10) is gypsum plank, above-mentioned steam barrier layer (8) is polyethylene sheeting or PE film, trim panel (10) and steam barrier layer (8) are fixed on basic unit's bearing wall (7) by holdfast, and the fixture gap utilizes encapsulant to seal.

3. condensation-proof external thermal insulated wall body structure according to claim 1, it is characterized in that: above-mentioned flame retardant type adiabator layer (5) is flame-retarded foamed plastic plate or glass wool, basic unit's bearing wall (7) outside also has leveling layer (6), and flame retardant type adiabator layer (5) adhesive sticks at leveling layer (6).

4. condensation-proof external thermal insulated wall body structure according to claim 1, it is characterized in that: above-mentioned moisture diffusion layer (4) is veneer or oriented wood chipboard.

5. condensation-proof external thermal insulated wall body structure according to claim 1, it is characterized in that: above-mentioned waterproofing course (3) is moistureproof paper or high polymer elastic coating material or polyethylene sheeting or bituminous waterproofing material.

6. condensation-proof external thermal insulated wall body structure according to claim 1, it is characterized in that: above-mentioned flame retardant type adiabator layer (5), moisture diffusion layer (4), waterproofing course (3) are fixed in basic unit's bearing wall (7) by fixture together, and the fixture gap utilizes encapsulant to seal.

7. condensation-proof external thermal insulated wall body structure according to claim 1, it is characterized in that: above-mentioned outer plaque (1) is fiber cement board or concrete slab, this outer plaque (1) is fixed on basic unit's bearing wall (7) by fixture, and the fixture gap utilizes encapsulant to seal.

8. condensation-proof external thermal insulated wall body structure according to claim 1, it is characterized in that: the outer through hole (13) on above-mentioned outer plaque (1) is comprised of through hole on skin and outer lower through-hole, and opening direction is oblique lower mode from inside to outside, and the ratio of perforated area sum and outer plaque (1) area is more than or equal to 2%, and the ratio of the volume of perforated area sum and outer space gas-bearing formation (2) is more than or equal to 0.05 (1/m), and the upper limit of perforated area is according to not affecting the outer plaque function and installing with the intensity that does not weaken outer plaque and determine; Internal layer through hole (11) on above-mentioned trim panel (10) is comprised of through hole on internal layer and internal layer lower through-hole; And the ratio of perforated area sum and trim panel (10) area is more than or equal to 2%, and the ratio of the volume of perforated area sum and inboard air layer (9) is more than or equal to 0.05 (1/m), and the upper limit of perforated area is determined according to the intensity that does not affect trim panel function and installation and do not weaken trim panel.

9. condensation-proof external thermal insulated wall body structure according to claim 1, it is characterized in that: the thickness of outside air layer (2) and inboard air layer (9) is all between 10mm～60mm.

10. condensation-proof external thermal insulated wall body structure according to claim 9, is characterized in that: Beijing, Harbin, city, three, Nanjing, inner air and outer air layer difference 18-30mm, 25-60mm, 10-25mm.

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