CN103452206B - A kind of diabatic process computational methods of civilian construction self heat insulation wall - Google Patents

Abstract

The invention discloses a kind of diabatic process computational methods of civilian construction self heat insulation wall, described heat-preserving wall comprises the interior brick wall layer near indoor side, the outer brick wall layer near outdoor side and overlap joint brick layer, described interior brick wall layer, outer brick wall layer and overlap joint brick layer are made up of some internal wall bricks, exterior wall tile and overlap joint brick respectively, described internal wall brick is arranged in parallel with corresponding exterior wall tile and is provided with at its two ends and overlaps brick with being arranged vertically with it, and described interior brick wall layer, outer brick wall layer and overlap joint brick layer surround into air layer.The present invention is by the optimal design to masonry wall structure, achieve under the condition not changing traditional brick building block production model, the heat-insulating property of exterior wall is improved, when not adopting heat insulating material, also southern area heat transfer coefficient of outer wall requirement can be met, engineering construction cost can be saved on the one hand, good heat insulating effect can also be played simultaneously and reduce the effect of building energy consumption.

Description

A kind of diabatic process computational methods of civilian construction self heat insulation wall

Technical field

The present invention relates to construction engineering technical field, particularly the diabatic process computational methods of a kind of civilian construction self heat insulation wall and this body of wall.

Background technology

Because building 80% of the energy input that always conducts heat is lost by heat transfer across wall, therefore, the improvement of thermal performance of building envelope has very important significance for building energy conservation.Adopt appropriate space enclosing structure parts and reasonably construction measure can meet the various requirements such as insulation, heat insulation, daylighting, ventilation, both ensure that the physical environment that indoor are good, again reduce energy consumption, this is the primary condition realizing building energy conservation.

The energy-saving design of space enclosing structure relate generally to because have exterior wall, roof, door and window, curtain wall etc.Exterior wall is the main body of architectural exterior-protecting construction, and its heat-insulating property directly affects the heat consumption of building, and external wall energy-saving occupies very important position in building energy conservation, and the heat consump-tion in transfer of exterior wall accounts for the 23%-34% of building total heat consumption according to statistics.Southern area (hot-summer and cold-winter area, hot summer and warm winter region) residential building, public building have carried out considered critical to the thermal transmittance limit value of external wall respectively for this reason.Visible enhancing exterior wall thermal property has important function for building energy conservation.

The method that urban architecture lays heat insulating material mainly through exterior wall improves exterior wall thermal property, but construction cost can be caused to increase owing to laying heat insulating material, and this seriously constrains the popularization of the civilian space enclosing structure power-saving technology of some rural area tradition.

Summary of the invention

The object of the invention is to: for above-mentioned Problems existing, under a kind of condition not changing traditional brick building block production model being provided, good heat insulating effect can being played and reduce the civilian construction self heat insulation wall of building energy consumption and the diabatic process computational methods of this body of wall.

The technical scheme of the technology of the present invention is achieved in that a kind of civilian construction self heat insulation wall, it is characterized in that: comprise the interior brick wall layer near indoor side, the outer brick wall layer near outdoor side and overlap joint brick layer, described interior brick wall layer, outer brick wall layer and overlap joint brick layer are made up of some internal wall bricks, exterior wall tile and overlap joint brick respectively, described internal wall brick is arranged in parallel with corresponding exterior wall tile and is provided with at its two ends and overlaps brick with being arranged vertically with it, and described interior brick wall layer, outer brick wall layer and overlap joint brick layer surround into air layer.

Civilian construction self heat insulation wall of the present invention, it scribbles dope layer respectively on the described interior brick wall layer side corresponding with outer brick wall layer, the inside wall that contacts with air layer, and the emissivity of coatings of described dope layer is less than or equal to 0.4.

Civilian construction self heat insulation wall of the present invention, internal wall brick described in it, exterior wall tile and overlap joint brick all stand to be put, and is staggered.

Civilian construction self heat insulation wall of the present invention, overlaps overlap joint brick two of brick layer respectively near indoor and outdoor described in it.

A kind of diabatic process computational methods of civilian construction self heat insulation wall as described above, it is characterized in that: comprise the heat transfer of air layer body of wall and the heat transfer of overlap joint brick wall body, the heat transfer of described air layer body of wall comprises double teacher: 1. heat passes to outside exterior wall in the mode of composite heat-exchange, 2. heat passes through exterior wall with heat-conducting mode, 3. inner side of outer wall passes to outside interior wall in the mode of composite heat-exchange, 4. heat is in the mode of heat conduction by interior wall, and 5. heat passes to indoor environment in the mode of composite heat-exchange; The heat transfer of described overlap joint brick wall body comprises three phases: 1. heat passes to overlap joint brick wall outer side in the mode of composite heat-exchange, and 2. heat is in the mode of heat conduction by overlap joint brick brick body wall, and 3. heat passes to indoor environment in the mode of composite heat-exchange.

Diabatic process computational methods of the present invention, is characterized in that:

The heat transfer of a, air layer body of wall:

1. outside wall surface heat convection, exterior surface of wall and atmospheric heat are with complex form heat exchange, and the heat flow density of this process can calculate with formula (one):

Q=h ₀(t _f0-t _w0) ... (1)

2. exterior wall heat conduction, heat passes through (interior wall is identical with exterior wall computational methods) from exterior wall outer surface in the mode of heat conduction, and the heat flow density of this process can calculate with formula (two):

$q=\frac{t_{w0}-t_{w1}}{{\mathrm{\δ}}_0/{\mathrm{\λ}}_z}$ (2)

3. air space heat exchange, heat passes through air layer in the mode of composite heat-exchange, this process can regard the heat transfer free convection in the confined space as, and the air layer in body of wall is vertical wall interlayer, heat transfer free convection Correlation equations and correlometer formula (three) as follows:

(3)

Grashof:

$Gr=\frac{g\mathrm{\α}(t_{w1}-t_{w2}){\mathrm{\δ}}_a^3}{{\mathrm{\ν}}^2}$ (4)

Equivalent surface coefficient of heat transfer can be drawn thus:

$h_e=\frac{{\mathrm{\λ}}_a}{{\mathrm{\δ}}_a}Nu$ (5)

Body of wall radiating surface thermal transmittance:

$h_r={\mathrm{\ϵC}}_b\frac{T_{w1}^4-T_{w2}^4}{T_{w1}-T_{w2}}\×{10}^{-8}$ (6)

Therefore air layer composite heat-exchange surface coefficient of heat transfer:

H ₁=h _e+ h _r(7)

Q=h ₁(t _w1-t _w2) ... (8)

4. interior wall heat conduction, heat passes through (interior wall is identical with exterior wall computational methods) from inner wall outer surface in the mode of heat conduction, and the heat flow density of this process can calculate with formula (two):

$q=\frac{t_{w2}-t_{w3}}{{\mathrm{\δ}}_0/{\mathrm{\λ}}_z+{\mathrm{\δ}}_c/{\mathrm{\λ}}_c}$ (9)

5. inner wall surface heat convection, wall-body energy saving and atmospheric heat are with complex form heat exchange, and the heat flow density of this process can calculate with formula (ten):

Q=h ₂(t _w3-t _f1) ... (10)

The heat transfer of b, overlap joint brick wall body:

Overlap joint brick wall inside and outside wall heat exchange design formulas, with the diabatic process of air layer body of wall, calculates with (ten) according to formula (), and overlap joint brick wall body heat transferring is pressed formula (11) and calculated:

$q^{\′}=\frac{t_{w0}-t_{w3}}{{\mathrm{\δ}}_1/{\mathrm{\λ}}_z}$ (11)

C, body of wall average heat transfer:

The overall coefficient of heat transfer of this body of wall can be drawn thus:

K=K _ka+K _sb ... (12)

$K_k=\frac{q}{t_{f0}-t_{f1}}$ (13)

$K_s=\frac{q^{\′}}{t_{f0}-t_{f1}}$ (14)

A is the ratio that hollow wall area accounts for whole wall area, m ²/ m ²;

B is the ratio that solid wall area accounts for whole wall area, m ²/ m ²;

Heat exchange calculates and adopts trial and error procedure, and tentative calculation process entails each section of heat flow density control errors is within 5%;

In above-mentioned design formulas, relevant parameter is as follows:

Q is by air layer body of wall heat flow density, W/m ²

H ₀for exterior wall external surface composite heat-exchange coefficient, W/ (m ²k)

T _f0for outside air temperature, DEG C;

T _w0for exterior wall outside surface temperature, DEG C

T _w1for inner side of outer wall surface temperature, DEG C

δ ₀for the thickness of brick, mm

λ _zfor the coefficient of thermal conductivity of brick, W/ (m ²k)

H _efor equivalent surface coefficient of heat transfer, W/ (m ²k)

λ _afor the coefficient of thermal conductivity of air, W/ (m ²k)

ε is the slin emissivity of brick

H ₁for air layer composite surface thermal transmittance, W/ (m ²k)

T _w3for interior wall inner surface temperature, DEG C

H ₂for body of wall mean thermal transmittance W/ (m ²k)

K is body of wall mean thermal transmittance W/ (m ²k)

λ _cfor the coefficient of thermal conductivity of cement mortar, W/ (m ²k)

Nu is nusselt number

H is air layer height, m

Gr is grashof number

G is local acceleration of gravity, m ²/ s

α is the coefficient of cubical expansion, 1/K

T _w2for interior wall outside surface temperature, DEG C

δ _afor air layer thickness, mm

ν is the dynamic viscosity of air under qualitative temperature, m ²/ s

H _rfor radiating surface thermal transmittance, W/ (m ²k)

C _bblackbody coefficient, W/ (m ²k ⁴)

T _f1for indoor air temperature, DEG C;

Q ' is by overlap joint brick wall body heat current density, W/m ²

δ ₁for the length of brick, mm

δ _cfor the thickness of cement mortar, mm.

The present invention is by the optimal design to masonry wall structure, achieve under the condition not changing traditional brick building block production model, the heat-insulating property of exterior wall is improved, when not adopting heat insulating material, also southern area heat transfer coefficient of outer wall requirement can be met, engineering construction cost can be saved on the one hand, good heat insulating effect can also be played simultaneously and reduce the effect of building energy consumption.

Accompanying drawing explanation

Fig. 1 is structural representation of the present invention.

Fig. 2 is Calculation of Heat Transfer process flow schematic diagram of the present invention.

Fig. 3 is civilian wall heat transfer coefficient (summer) schematic diagram under different emissivity.

Fig. 4 is civilian wall heat transfer coefficient (winter) schematic diagram under different emissivity.

Fig. 5 is civilian wall heat transfer coefficient under different emissivity (excessive season) schematic diagram.

Mark in figure: 1 is internal wall brick, and 2 is exterior wall tile, 3 is overlap joint brick, and 4 is air layer, and 5 is dope layer.

Detailed description of the invention

Below in conjunction with accompanying drawing, the present invention is described in detail.

In order to make object of the present invention, technical scheme and advantage clearly understand, below in conjunction with drawings and Examples, the technology of the present invention is further elaborated.Should be appreciated that specific embodiment described herein only in order to explain the present invention, and be not used in restriction invention.

As shown in Figure 1, a kind of civilian construction self heat insulation wall, comprise the interior brick wall layer near indoor side, outer brick wall layer near outdoor side and overlap joint brick layer, described interior brick wall layer, outer brick wall layer and overlap joint brick layer are respectively by some internal wall bricks 1, exterior wall tile 2 and overlap joint brick 3 form, described internal wall brick 1 is arranged in parallel with corresponding exterior wall tile 2 and is provided with at its two ends and overlaps brick 3 with being arranged vertically with it, overlap joint brick 3 two of described overlap joint brick layer is respectively near indoor and outdoor, described interior brick wall layer, outer brick wall layer and overlap joint brick layer surround into air layer 4, described internal wall brick 1, exterior wall tile 2 and overlap joint brick 3 all stand to be put, and be staggered.

Wherein, the described interior brick wall layer side corresponding with outer brick wall layer, the inside wall that contacts with air layer 4 scribble dope layer 5 respectively, and the emissivity of coatings of described dope layer 5 is less than or equal to 0.4.

Specific embodiment:

Embodiment building overview: this external wall body of wall height 3.3m, wide 10.3m, use brickwork to be of a size of 240 × 115 × 53mm.Calculating parameter input parameter is as following table:

Calculating parameter input table

Wherein, computational methods flow process as shown in Figure 2.

Through above hypothesis, the diabatic process computational methods of civilian construction self heat insulation wall described above, comprise the heat transfer of air layer body of wall and the heat transfer of overlap joint brick wall body, the heat transfer of described air layer body of wall comprises double teacher: 1. heat passes to outside exterior wall in the mode of composite heat-exchange, 2. heat passes through exterior wall with heat-conducting mode, 3. inner side of outer wall passes to outside interior wall in the mode of composite heat-exchange, 4. heat is in the mode of heat conduction by interior wall, and 5. heat passes to indoor environment in the mode of composite heat-exchange; The heat transfer of described overlap joint brick wall body comprises three phases: 1. heat passes to overlap joint brick wall outer side in the mode of composite heat-exchange, and 2. heat is in the mode of heat conduction by overlap joint brick brick body wall, and 3. heat passes to indoor environment in the mode of composite heat-exchange.

Wherein, the heat transfer of a, air layer body of wall:

1. outside wall surface heat convection, exterior surface of wall and atmospheric heat are with complex form heat exchange, and the heat flow density of this process can calculate with formula (one):

Q=h ₀(t _f0-t _w0) ... (1)

2. exterior wall heat conduction, heat passes through (interior wall is identical with exterior wall computational methods) from exterior wall outer surface in the mode of heat conduction, and the heat flow density of this process can calculate with formula (two):

$q=\frac{t_{w0}-t_{w1}}{{\mathrm{\δ}}_0/{\mathrm{\λ}}_z}$ (2)

3. air space heat exchange, heat passes through air layer in the mode of composite heat-exchange, this process can regard the heat transfer free convection in the confined space as, and the air layer in body of wall is vertical wall interlayer, heat transfer free convection Correlation equations and correlometer formula (three) as follows:

(3)

Grashof:

$Gr=\frac{g\mathrm{\α}(t_{w1}-t_{w2}){\mathrm{\δ}}_a^3}{{\mathrm{\ν}}^2}$ (4)

Equivalent surface coefficient of heat transfer can be drawn thus:

$h_e=\frac{{\mathrm{\λ}}_a}{{\mathrm{\δ}}_a}Nu$ (5)

Body of wall radiating surface thermal transmittance:

$h_r={\mathrm{\ϵC}}_b\frac{T_{w1}^4-T_{w2}^4}{T_{w1}-T_{w2}}\×{10}^{-8}$ (6)

Therefore air layer composite heat-exchange surface coefficient of heat transfer:

H ₁=h _e+ h _r(7)

Q=h ₁(t _w1-t _w2) ... (8)

4. interior wall heat conduction, heat passes through (interior wall is identical with exterior wall computational methods) from inner wall outer surface in the mode of heat conduction, and the heat flow density of this process can calculate with formula (two):

$q=\frac{t_{w2}-t_{w3}}{{\mathrm{\δ}}_0/{\mathrm{\λ}}_z+{\mathrm{\δ}}_c/{\mathrm{\λ}}_c}$ (9)

5. inner wall surface heat convection, wall-body energy saving and atmospheric heat are with complex form heat exchange, and the heat flow density of this process can calculate with formula (ten):

Q=h ₂(t _w3-t _f1) ... (10)

The heat transfer of b, overlap joint brick wall body:

Overlap joint brick wall inside and outside wall heat exchange design formulas, with the diabatic process of air layer body of wall, calculates with (ten) according to formula (), and overlap joint brick wall body heat transferring is pressed formula (11) and calculated:

$q^{\′}=\frac{t_{w0}-t_{w3}}{{\mathrm{\δ}}_1/{\mathrm{\λ}}_z}$ (11)

C, body of wall average heat transfer:

The overall coefficient of heat transfer of this body of wall can be drawn thus:

K=K _ka+K _sb ... (12)

$K_k=\frac{q}{t_{f0}-t_{f1}}$ (13)

$K_s=\frac{q^{\′}}{t_{f0}-t_{f1}}$ (14)

A is the ratio that hollow wall area accounts for whole wall area, m ²/ m ²;

B is the ratio that solid wall area accounts for whole wall area, m ²/ m ²;

Heat exchange calculates and adopts trial and error procedure, and tentative calculation process entails each section of heat flow density control errors is within 5%;

In above-mentioned design formulas, relevant parameter is as follows:

Q is by air layer body of wall heat flow density, W/m ²

H ₀for exterior wall external surface composite heat-exchange coefficient, W/ (m ²k)

T _f0for outside air temperature, DEG C;

T _w0for exterior wall outside surface temperature, DEG C

T _w1for inner side of outer wall surface temperature, DEG C

δ ₀for the thickness of brick, mm

λ _zfor the coefficient of thermal conductivity of brick, W/ (m ²k)

H _efor equivalent surface coefficient of heat transfer, W/ (m ²k)

λ _afor the coefficient of thermal conductivity of air, W/ (m ²k)

ε is the slin emissivity of brick

H ₁for air layer composite surface thermal transmittance, W/ (m ²k)

T _w3for interior wall inner surface temperature, DEG C

H ₂for body of wall mean thermal transmittance W/ (m ²k)

K is body of wall mean thermal transmittance W/ (m ²k)

λ _cfor the coefficient of thermal conductivity of cement mortar, W/ (m ²k)

Nu is nusselt number

H is air layer height, m

Gr is grashof number

G is local acceleration of gravity, m ²/ s

α is the coefficient of cubical expansion, 1/K

T _w2for interior wall outside surface temperature, DEG C

δ _afor air layer thickness, mm

ν is the dynamic viscosity of air under qualitative temperature, m ²/ s

H _rfor radiating surface thermal transmittance, W/ (m ²k)

C _bblackbody coefficient, W/ (m ²k ⁴)

T _f1for indoor air temperature, DEG C;

Q ' is by overlap joint brick wall body heat current density, W/m ²

δ ₁for the length of brick, mm

δ _cfor the thickness of cement mortar, mm.

Result of calculation: as shown in Fig. 3 to 5, as can be seen from the figure, no matter in which, thermal characteristic of wall is good, and (body of wall mean thermal transmittance is about 0.7W/m in season ²k), energy-conserving construction wall thermal technology requirement is substantially met.As can be seen here, one aspect of the present invention can save engineering construction cost, can also play good heat insulating effect simultaneously and reduce the effect of building energy consumption.

Claims (1)

1. the diabatic process computational methods of a civilian construction self heat insulation wall, described civilian construction self heat insulation wall comprises the interior brick wall layer near indoor side, outer brick wall layer near outdoor side and overlap joint brick layer, described interior brick wall layer, outer brick wall layer and overlap joint brick layer are respectively by some internal wall bricks (1), exterior wall tile (2) and overlap joint brick (3) composition, described internal wall brick (1) is arranged in parallel with corresponding exterior wall tile (2) and is provided with at its two ends overlap brick (3) with being arranged vertically with it, described interior brick wall layer, outer brick wall layer and overlap joint brick layer surround into air layer (4), it is characterized in that: described diabatic process computational methods comprise the heat transfer of air layer body of wall and the heat transfer of overlap joint brick wall body, the heat transfer of described air layer body of wall comprises double teacher: 1. heat passes to outside exterior wall in the mode of composite heat-exchange, 2. heat passes through exterior wall with heat-conducting mode, 3. inner side of outer wall passes to outside interior wall in the mode of composite heat-exchange, 4. heat passes through interior wall in the mode of heat conduction, 5. heat passes to indoor environment in the mode of composite heat-exchange, the heat transfer of described overlap joint brick wall body comprises three phases: 1. heat passes to overlap joint brick wall outer side in the mode of composite heat-exchange, and 2. heat is in the mode of heat conduction by overlap joint brick brick body wall, and 3. heat passes to indoor environment in the mode of composite heat-exchange,

The heat transfer of a, air layer body of wall:

1. wall face heat convection, exterior surface of wall and atmospheric heat are with complex form heat exchange, and the heat flow density formula () of this process calculates:

Q=h ₀(t _f0-t _w0) ... (1)

2. exterior wall heat conduction, heat passes through from exterior wall outer surface in the mode of heat conduction, and the heat flow density formula (two) of this process calculates:

$q=\frac{t_{w0}-t_{w1}}{{\mathrm{\δ}}_0/{\mathrm{\λ}}_z}$ (2)

3. air space heat exchange, heat passes through air layer in the mode of composite heat-exchange, this process regards the heat transfer free convection in the confined space as, and the air layer in body of wall is vertical wall interlayer, heat transfer free convection Correlation equations and correlometer formula (three) as follows:

(3)

Grashof:

$Gr=\frac{g\mathrm{\α}\left(t_{w1}-t_{w2}\right){\mathrm{\δ}}_a^3}{{\mathrm{\ν}}^2}$ (4)

Equivalent surface coefficient of heat transfer can be drawn thus:

$h_e=\frac{{\mathrm{\λ}}_a}{{\mathrm{\δ}}_a}Nu$ (5)

Body of wall radiating surface thermal transmittance:

$h_r={\mathrm{\ϵC}}_b\frac{T_{w1}^4-T_{w2}^4}{T_{w1}-T_{w2}}\×{10}^{-8}$ (6)

Therefore air layer composite heat-exchange surface coefficient of heat transfer:

H ₁=h _e+ h _r(7)

Q=h ₁(t _w1-t _w2) ... (8)

4. interior wall heat conduction, heat passes through from inner wall outer surface in the mode of heat conduction, and the heat flow density formula (nine) of this process calculates:

$q=\frac{t_{w2}-t_{w3}}{{\mathrm{\δ}}_0/{\mathrm{\λ}}_z+{\mathrm{\δ}}_c/{\mathrm{\λ}}_c}$ (9)

5. inner wall surface heat convection, wall-body energy saving and atmospheric heat are with complex form heat exchange, and the heat flow density formula (ten) of this process calculates:

Q=h ₂(t _w3-t _f1) ... (10)

The heat transfer of b, overlap joint brick wall body:

Overlap joint brick wall inside and outside wall heat exchange design formulas, with the diabatic process of air layer body of wall, calculates with (ten) according to formula (), and overlap joint brick wall body heat transferring is pressed formula (11) and calculated:

$q^{\′}=\frac{t_{w0}-t_{w3}}{{\mathrm{\δ}}_1/{\mathrm{\λ}}_z}$ (11)

C, body of wall average heat transfer:

The overall coefficient of heat transfer of this body of wall can be drawn thus:

K=K _ka+K _sb ... (12)

$K_k=\frac{q}{t_{f0}-t_{f1}}$ (13)

$K_s=\frac{q^{\′}}{t_{f0}-t_{f1}}$ (14)

A is the ratio that hollow wall area accounts for whole wall area, m ²/ m ²;

B is the ratio that solid wall area accounts for whole wall area, m ²/ m ²;

Heat exchange calculates and adopts trial and error procedure, and tentative calculation process entails each section of heat flow density control errors is within 5%;

In above-mentioned design formulas, relevant parameter is as follows:

Q is by air layer body of wall heat flow density, W/m ²

H ₀for exterior wall external surface composite heat-exchange coefficient, W/ (m ²k)

T _f0for outside air temperature, DEG C;

T _w0for exterior wall outside surface temperature, DEG C

T _w1for inner side of outer wall surface temperature, DEG C

δ ₀for the thickness of brick, mm

λ _zfor the coefficient of thermal conductivity of brick, W/ (m ²k)

H _efor equivalent surface coefficient of heat transfer, W/ (m ²k)

λ _afor the coefficient of thermal conductivity of air, W/ (m ²k)

ε is the slin emissivity of brick

H ₁for air layer composite surface thermal transmittance, W/ (m ²k)

T _w3for interior wall inner surface temperature, DEG C

H ₂for body of wall mean thermal transmittance W/ (m ²k)

K is body of wall mean thermal transmittance W/ (m ²k)

λ _cfor the coefficient of thermal conductivity of cement mortar, W/ (m ²k)

Nu is nusselt number

H is air layer height, m

Gr is grashof number

G is local acceleration of gravity, m ²/ s

α is the coefficient of cubical expansion, 1/K

T _w2for interior wall outside surface temperature, DEG C

δ _afor air layer thickness, mm

ν is the dynamic viscosity of air under qualitative temperature, m ²/ s

H _rfor radiating surface thermal transmittance, W/ (m ²k)

C _bblackbody coefficient, W/ (m ²k ⁴)

T _f1for indoor air temperature, DEG C;

Q ' is by overlap joint brick wall body heat current density, W/m ²

δ ₁for the length of brick, mm

δ _cfor the thickness of cement mortar, mm.