An automatic water permeation and drainage system and method for external wall thermal insulation

Abstract

The application is an automatic water seepage and drainage system and method for external wall external thermal insulation. The system comprises a drainage cavity between the wall and the thermal insulation layer as a drainage passage; a perforated drainage pipe is also provided, which is inserted into the external wall thermal insulation layer, and the side wall is provided with holes; the inner surface of the perforated drainage pipe is covered with a film, and the surface of the pipe is provided with a waterproof and vapor-permeable film; the system further comprises a sealing device, a sealing cover plate is arranged on the upper end of the pipe, so that the pipe forms a sealed state on the upper end of the thermal insulation layer; the system further comprises a connecting horizontal pipe, a sealing horizontal pipe is used to connect the vertical drainage pipe at the lower part of the system; the system further comprises a system drainage port, a water outlet is arranged at the lower end of the system; the system further comprises a water suction device, a water suction device is connected to the end, so that the water vapor in the system is sucked out, and the dryness of the thermal insulation and the wall is further maintained. The water in the wall is sucked to the drainage cavity through negative pressure, and the water between the wall and the thermal insulation is automatically drained through the joint action of gravity and negative pressure, so that the inside of the wall and the thermal insulation system is kept dry.

Description

Technical Field

[0001] This invention relates to the field of self-drainage technology, and more specifically to an automatic drainage system and method for external wall insulation. Background Technology

[0002] External wall insulation systems have become an important component of building energy conservation systems. Currently, commonly used external wall insulation systems in China include thin-plaster external wall insulation systems, adhesive-anchored external wall insulation systems, and prefabricated new external wall insulation systems (sandwich insulation). Among these, the thin-plaster external wall insulation system is the most commonly used. This system has advantages such as ease of operation, good insulation performance, and prevention of thermal bridging. The main steps of this insulation system include leveling the base wall, pasting the insulation board, installing fasteners, applying mortar, laying the mesh fabric, applying the top mortar and water-resistant putty, and finally applying primer and stone-like paint. This system is technically mature and has advantages such as simple construction and high cost-effectiveness.

[0003] However, in practical projects, as the requirements for building energy conservation regarding exterior wall insulation have gradually increased, this insulation system has also presented a series of problems. For example, in southern and central regions, due to the high air humidity, water vapor enters the insulation system through gaps in the exterior wall insulation due to rain, snow, and freeze-thaw cycles. This water vapor cannot be discharged in time, and the large amount of moisture will greatly reduce the thermal insulation performance of the exterior insulation system. When the insulation layer is made of insulating mortar, the impact is even greater. This moisture accumulates in the wall over time, causing the exterior insulation to peel off from the wall. If the quality control of polymer mortar construction is not in place, hollow areas will form, eventually leading to detachment. Summary of the Invention

[0004] The present invention proposes an automatic drainage system for external wall insulation, which can at least solve the above-mentioned technical problems.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] An automatic drainage system for external wall insulation includes the following structure:

[0007] A drainage cavity is set between the wall and the insulation layer as a drainage channel;

[0008] Perforated drainage pipes are also installed and inserted into the external wall insulation layer. Holes are added to the side walls, and fixing measures are used to secure them to the wall.

[0009] The inner surface of the perforated drainage pipe is covered with a membrane, and a waterproof and breathable membrane is installed on the surface of the pipe.

[0010] It also includes a sealing device, a sealing cover plate at the top of the pipe, so that the pipe is sealed at the top of the insulation layer;

[0011] It also includes a connecting horizontal pipe. At the bottom of the system, a sealed horizontal pipe is used to connect to the vertical drainage pipe. The horizontal pipe is sloped at 0.5% to 1% to concentrate the drainage to one end.

[0012] It also includes a system drain outlet. At the bottom of the system, a drain outlet is set up so that when the water volume is large, it can be discharged outdoors through the drain outlet or connected to the drainage system.

[0013] It also includes a water absorption device. When the water volume is large or during regular inspections, an external water absorption device is connected at the end to extract the water vapor in the system, further maintaining the insulation and keeping the wall dry.

[0014] Furthermore, the cavity shape of the drainage cavity is a flat trapezoid.

[0015] Furthermore, the drainage cavity is embedded with a moisture-absorbing material, which has an adsorption effect on moisture in the wall.

[0016] Furthermore, the perforated drain pipe has a flat trapezoidal cross-sectional shape with a sheet-like protrusion in the middle.

[0017] Furthermore, the perforated drainage pipes are made of rigid polyurethane material.

[0018] Furthermore, the perforated drainage pipes are connected by connectors using a snap-fit ​​method, and pre-drilled holes are provided for easy fixing of the insulation anchors.

[0019] Furthermore, it also includes intermediate inspection drains, with intermediate inspection ports set between building floors. The inspection ports are sloped through horizontal pipes and set in easily accessible locations such as balconies and exterior window side walls. Through the inspection ports, it is possible to observe whether there is a large amount of water vapor inside the insulation.

[0020] On the other hand, the present invention also discloses an automatic drainage method for external wall insulation, comprising the following steps:

[0021] By utilizing the negative pressure of the air within the wall, pipes capable of holding water vapor are installed in the wall to adsorb surrounding water vapor. This creates negative pressure within the wall, causing the surrounding water vapor to be discharged into the drainage pipe through holes. A drain outlet is located at the lower end, directly connected to the atmosphere. When the pressure between water molecules in the upper part is higher, it will automatically drain towards the lower pressure area at the end, thus automatically expelling moisture from the wall through the drain outlet at the lower end of the drainage pipe, effectively preventing water vapor from accumulating within the wall.

[0022] Furthermore, when the pressure difference between water molecules inside the wall is not large and water vapor cannot be discharged automatically, a water absorption device is installed at the end to draw water vapor out of the system and promote its discharge.

[0023] Furthermore, this invention also discloses a method for designing a pipeline drainage system, comprising the following steps:

[0024] First, the calculation and layout of the internal drainage system for thermal insulation are carried out based on the building facade.

[0025] The moisture content per unit area of ​​the wall within the insulation layer is calculated by combining the building height and pipe spacing. The moisture content needs to be considered in conjunction with the wall material, insulation material and thickness, as well as climate characteristics and the duration of the rainy season. Then, the maximum drainage capacity of the area is calculated by combining the moisture content per unit area of ​​the wall with the wall area between the pipes. Finally, the pipe cross-section size is combined to calculate and select a suitable pipe cross-section. When the requirements cannot be met, the spacing should be reduced or the pipe diameter should be increased.

[0026] Furthermore, the pipes should be arranged in conjunction with the building facade, with the pipes evenly distributed on the facade and the horizontal spacing between them being 1 to 2 meters. Before the insulation construction, the pipes should be fixed to the wall with thermal break anchors. At least two fixing anchors should be set on both sides of each pipe section. The specific number should be determined according to the calculation.

[0027] The interlayer spacing is designed in conjunction with the insulation module, and a snap-on connector is set. The connector has a reserved hole for fixing the insulation anchor, which facilitates the passage of the insulation anchor. The snap-on connector also has a rectangular plate-shaped protrusion, which also serves as an insulation support. This allows the weight of the insulation layer to be transferred to the exterior wall through the anchor, increasing the firmness and safety of the insulation installation.

[0028] The building's ground floor is equipped with horizontal water collection pipes. The pipes are sloped according to the actual conditions, and the bottom of the slope is equipped with a drain outlet that leads directly to the outdoor air or drainage system. The bottom of the drain outlet should be directly connected to the atmosphere to avoid negative pressure and backflow.

[0029] As can be seen from the above technical solution, the automatic drainage system for external wall insulation of the present invention draws water from the wall into the drainage chamber through negative pressure, and sets a drain outlet at the end, so that the water between the wall and the insulation is automatically discharged through the combined action of gravity and negative pressure, keeping the wall and the interior of the insulation system dry.

[0030] This invention effectively solves the problem of insulation detachment caused by high moisture content in external wall insulation. The moisture content of an external insulation system is a crucial indicator of its lifespan. When polymer mortar has high moisture content, its bonding strength decreases significantly, easily leading to delamination and cracking of the insulation system. This phenomenon is exacerbated by freezing conditions. Simultaneously, changes in environmental temperature cause dimensional changes in materials, a major factor damaging the external insulation system. When temperature changes combine with rain or freezing, hollow areas and detachment can occur. By incorporating a cavity in the insulation system that adsorbs water vapor, water vapor within the wall can be systematically and promptly released, preventing it from lingering within the wall and insulation layer. This maintains dryness and suitable humidity in the wall and insulation layer, effectively preventing the problem of external insulation detachment. Attached Figure Description

[0031] Figure 1 This is a system schematic diagram according to an embodiment of the present invention;

[0032] Figure 2 This is a pipe elevation layout diagram according to an embodiment of the present invention;

[0033] Figure 3 This is a pipe installation structure diagram according to an embodiment of the present invention;

[0034] Figure 4 This is a cross-sectional structural diagram of the pipe according to an embodiment of the present invention;

[0035] Figure 5 This is a pipe connection structure diagram according to an embodiment of the present invention. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments.

[0037] An automatic drainage system for external wall insulation according to an embodiment of the present invention includes:

[0038] The drainage cavity is a flat trapezoidal shape to maximize the contact area with the wall and increase the adsorption area and capacity for capillary water. The drainage channel between the wall and the insulation layer is embedded with moisture-absorbing material, which has an adsorption effect on the moisture in the wall.

[0039] The perforated drainage pipe has a flat trapezoidal cross-section with a plate-like protrusion in the middle for easy insertion into the external wall insulation. The pipe is made of rigid polyurethane material, which has a certain strength and meets the insulation performance requirements. Holes are added to the side wall, and fixing measures are used to fix it to the wall.

[0040] The inner surface of the pipe is covered with a membrane, and a waterproof and breathable membrane is set on the surface of the pipe. Water vapor can enter directly but is not easy to escape, effectively absorbing water vapor and keeping it in the pipe.

[0041] Connectors are used to connect pipes using a snap-fit ​​connection method, and pre-drilled holes are provided for easy fixing of insulation anchors;

[0042] The sealing device includes a sealing cover plate at the top of the pipe, which creates a seal on the top of the insulation layer.

[0043] Connect the horizontal pipe. At the bottom of the system, use a sealed horizontal pipe to connect the vertical drainage pipe. Set the horizontal pipe with a slope of 0.5% to 1% so that the drainage is concentrated at one end. When the building has a large width, the slope can be set at both ends.

[0044] The system drain outlet is located at the bottom of the system. When the water volume is large, it can be discharged outdoors through the drain outlet or connected to the drainage system.

[0045] When the water volume is large or during regular inspections, a water absorption device can be connected to the end to extract the water vapor in the system, further maintaining the insulation and keeping the wall dry.

[0046] Intermediate inspection outlets are installed between building floors. The inspection outlets are sloped through horizontal pipes and located in easily accessible locations such as balconies and exterior window side walls. Through the inspection outlets, it is possible to observe whether there is a large amount of water vapor inside the insulation.

[0047] Working principle:

[0048] In theory, in an external wall insulation system, the wall and the insulation are in a sealed state. If there is moisture, it will flow into the pores. When the moisture in the pores accumulates to a certain extent, cracks will form on the wall surface. As the cracks continue to widen, they will eventually fall off.

[0049] This invention utilizes the negative pressure of air within a wall. A pipe capable of holding water vapor is installed within the wall, creating an adsorption effect on surrounding water vapor. This negative pressure causes the surrounding water vapor to drain through openings into the drainage pipe. A drain outlet at the lower end is directly connected to the atmosphere. When the pressure between water molecules is higher at the top, it automatically drains towards the lower pressure area at the bottom, thus automatically expelling moisture from the wall through the drain outlet at the bottom of the pipe, effectively preventing water vapor accumulation within the wall. When the pressure difference between water molecules within the wall is small enough that water vapor cannot drain automatically, a water suction device can be installed at the end to draw water vapor out of the system.

[0050] Meanwhile, this invention also discloses a calculation method for the design of a pipeline drainage system, including:

[0051] First, the internal drainage system is calculated and laid out based on the building facade. Then, the moisture content per unit area of ​​the wall within the insulation layer is calculated by combining the building floor height and pipe spacing. The moisture content needs to be comprehensively considered in conjunction with the wall material, insulation material and thickness, climate characteristics, and rainy season duration. Next, the maximum drainage volume of the area is calculated by combining the moisture content per unit area of ​​the wall with the wall area between the pipes. Finally, the appropriate pipe cross-section is selected based on the pipe cross-section size. When the requirements cannot be met, the spacing should be reduced or the pipe diameter should be increased.

[0052] The specific calculations are as follows:

[0053] 1) Calculation of rainwater volume on exterior walls

[0054] When rainwater acts on a building facade, the moisture gradually accumulates and gathers. The amount of accumulation depends on the properties of the building's surface materials, the amount of rainfall, and the wind driving force. When rainwater hits the building facade, it is first absorbed by the wall and then accumulates. When the accumulation exceeds the absorption capacity, it begins to converge downwards. The top and corners of the building receive the most rainwater, which is usually accompanied by wind. Under ideal conditions, the rainwater accumulation process on the building's exterior walls involves the formation of a water film on the surface of the exterior walls when rainfall occurs, and then the water gathers towards the lower part of the exterior walls. From the perspective of the amount of rainwater deposited on the building's exterior walls, the amount of rainwater deposited on the large vertical wall surface (rbv) is calculated using the empirical formula ASHRAE 160P, as shown in equation (1).

[0055] r bv =F E ·F D ·F L ·U·cosθ·r h (1)

[0056] In the formula, rbv is the amount of rainwater deposited on the vertical wall surface [kg / (m2·h)]; F E F is the rainfall exposure coefficient; D The rainwater deposition coefficient is 0.35 for walls under steeply sloping roofs, 0.35 for walls under gently sloping roofs, and 1.00 for unobstructed walls; F L This is an empirical constant, 0.2 kg·s / (m²). 3 • mm); U is the hourly average wind speed at a height of 10 m (m / s); θ is the angle between the wind and the wall normal (°); rh is the rainfall intensity in the horizontal direction (mm / h). The rainfall exposure coefficient can be obtained from Table 1.

[0057] Table 1 Rainfall Exposure Coefficient

[0058]

[0059] In the absence of data, the amount of rainwater deposited is taken as an empirical value of 1% of the rainwater reaching the exterior facade.

[0060] Considering the prevailing wind direction, wind-driven rain coefficient, building orientation, topographical influence, obstruction from nearby external buildings, and wall type, including its shape and height, the calculation formulas for wind-driven rain are Equations (2) and (3).

[0061] D WA =D A ·R·T·O·W (2)

[0062] D WS =D S ·R·T·O·W (3)

[0063] In the formula, D A The annual average wind-driven rain index (L / y) for a specific direction of the building's exterior wall; D S The wind-driven rain index is defined as the maximum hourly precipitation (L / h) at a specific time period for a specific direction of the building's exterior wall; R is the ground roughness; T is the topographic coefficient; O is the shading coefficient of the building's exterior wall; W is the rainwater coefficient of the exterior wall, which is the ratio of the amount of rainwater reaching the exterior wall facade per unit area to the amount of rainwater in the free space.

[0064] (2) Drainage Piping System Calculation

[0065] The amount of rainwater deposited per unit area of ​​the exterior wall under certain climatic conditions is calculated using the above formula. Considering the actual wall surface and the spacing of the drainage pipes that can be arranged, the amount of rainwater deposited between two pipes on each floor is calculated. Then, the cross-sectional area of ​​the pipe is calculated based on this area. Because the pipe cross-section is irregular, a certain margin needs to be reserved. Therefore, a conversion factor of 1.2 to 1.3 times needs to be considered in the calculation structure to finally obtain the pipe size.

[0066] The cross-sectional dimensions are between 0.03 and 0.05 m. 2 Ideally, when the size is greater than 0.05㎡, it should be divided into two smaller pipes. At the same time, calculations should be made based on the maximum rainy season water volume in the actual project area to ensure smooth drainage. Detailed implementation method:

[0068] Based on the above calculation results, the pipes should be arranged in conjunction with the building facade. The pipes should be evenly distributed on the facade with a horizontal spacing of 1 to 2 meters. Before the insulation construction, the pipes should be fixed to the wall with thermal break anchors. At least two anchors should be installed on both sides of each pipe section.

[0069] The spacing between layers is approximately 1.2 to 1.5 meters (the specific dimensions depend on the insulation module). Clip-on connectors are installed, with pre-drilled holes for insulation anchor bolts to facilitate their passage. The clips also feature rectangular protrusions that serve as insulation supports, allowing the weight of the insulation layer to be transferred to the exterior wall through the anchor bolts, thus increasing the stability and safety of the insulation installation.

[0070] The building's ground floor is equipped with horizontal water collection pipes. The pipes are sloped according to the actual conditions, and the bottom of the slope is equipped with a drain outlet that leads directly to the outdoor air or drainage system. Note that the bottom of the drain outlet should be directly connected to the atmosphere to avoid negative pressure and backflow.

[0071] Preferred Design 1: Inspection ports are set up near the actual facade between floors. Inspection ports are preferentially installed on the side walls of exterior windows, balcony side walls, etc. The horizontal pipe of the inspection port can be appropriately sloped and a glass observation window is set at the end. When the water volume is large, the sealing cover can be opened for drainage.

[0072] Preferred Design 2: Install horizontal water collection pipes on the ground floor of the building. The horizontal pipes should be sloped according to the actual situation. At the bottom of the slope, there should be a drain outlet that leads directly to the outdoor air or drainage system. The bottom of the drain outlet should be directly connected to the atmosphere to avoid negative pressure and backflow.

[0073] In preferred design 3, the bottom drain outlet can be connected to an external suction device. When necessary, suction can be performed to further reduce the moisture content inside the wall and keep the wall dry.

[0074] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An automatic drainage system for external wall insulation, characterized in that, Includes the following structure, A drainage cavity is set between the wall and the insulation layer as a drainage channel; Perforated drainage pipes are also installed and inserted into the external wall insulation layer. Holes are added to the side walls, and fixing measures are used to secure them to the wall. The inner surface of the perforated drainage pipe is covered with a membrane, and a waterproof and breathable membrane is installed on the surface of the pipe. It also includes a sealing device, a sealing cover plate at the top of the pipe, so that the pipe is sealed at the top of the insulation layer; It also includes a connecting horizontal pipe. At the bottom of the system, a sealed horizontal pipe is used to connect to the vertical drainage pipe. The horizontal pipe is sloped at 0.5% to 1% to concentrate the drainage to one end. It also includes a system drain outlet. At the bottom of the system, a drain outlet is set up so that when the water volume is large, it can be discharged outdoors through the drain outlet or connected to the drainage system. It also includes a water absorption device. When the water volume is large or during regular inspections, an external water absorption device is connected at the end to extract the water vapor in the system, further maintaining the insulation and keeping the wall dry.

2. The automatic drainage system for external wall insulation according to claim 1, characterized in that: The drainage cavity has a flat trapezoidal shape.

3. The automatic drainage system for external wall insulation according to claim 1, characterized in that: The drainage cavity is embedded with moisture-absorbing material, which has an adsorption effect on moisture in the wall.

4. The automatic drainage system for external wall insulation according to claim 1, characterized in that: The perforated drainage pipe has a flat trapezoidal cross-section with a sheet-like protrusion in the middle.

5. The automatic drainage system for external wall insulation according to claim 1, characterized in that: The perforated drainage pipes are made of rigid polyurethane material.

6. The automatic drainage system for external wall insulation according to claim 1, characterized in that: The perforated drainage pipes are connected by connectors using a snap-fit ​​method, and pre-drilled holes are provided for easy fixing of the insulation anchors.

7. The automatic drainage system for external wall insulation according to claim 1, characterized in that: It also includes intermediate inspection drains, which are set up between building floors. The inspection ports are sloped by horizontal pipes and set in easily accessible locations such as balconies and exterior window side walls. Through the inspection ports, it is possible to observe whether there is a large amount of water vapor inside the insulation.

8. An automatic drainage method for external wall insulation, characterized in that: Includes the following steps, By utilizing the negative pressure of the air inside the wall, pipes that can hold water vapor are installed in the wall to adsorb the surrounding water vapor. The water vapor inside the wall will form a negative pressure, and the surrounding water vapor will be discharged into the drainage pipe through the holes due to the negative pressure. A drain outlet is set at the lower end, which is directly connected to the atmosphere. When the pressure between water molecules in the upper part is relatively high, it will automatically be discharged to the lower water pressure at the end, so that the water inside the wall will be automatically discharged from the drain outlet at the end of the lower drainage pipe, thus effectively preventing water vapor from accumulating inside the wall. It also includes installing a water suction device at the end when the pressure difference between water molecules inside the wall is not large and water vapor cannot be discharged automatically, so as to draw water vapor out of the system and promote the discharge of water vapor.

9. A design method for a pipeline drainage system, characterized in that: Includes the following steps, First, the calculation and layout of the internal drainage system for thermal insulation are carried out based on the building facade. The moisture content per unit area of ​​the wall within the insulation layer is calculated by combining the building height and pipe spacing. The moisture content needs to be considered in conjunction with the wall material, insulation material and thickness, as well as climate characteristics and the duration of the rainy season. Then, the maximum drainage capacity of the area is calculated by combining the moisture content per unit area of ​​the wall with the wall area between the pipes. Finally, the pipe cross-section size is combined to calculate and select a suitable pipe cross-section. When the requirements cannot be met, the spacing should be reduced or the pipe diameter should be increased.

10. A pipe drainage system design method according to claim 9, characterized in that: Includes the following steps, The pipes are arranged in conjunction with the building facade, and the pipes are evenly distributed on the facade with a horizontal spacing of 1 to 2 meters. Before the insulation construction, the pipes are fixed to the wall with thermal break anchors. At least 2 anchors are installed on both sides of each pipe section, located at 1 / 4 of the distance from the top and bottom. When the pipe height is high, the number and type of anchors need to be calculated and determined based on the pipe size and height. The interlayer spacing is designed in conjunction with the insulation module, and a snap-on connector is set. The connector has a reserved hole for fixing the insulation anchor, which facilitates the passage of the insulation anchor. The snap-on connector also has a rectangular plate-shaped protrusion, which also serves as an insulation support. This allows the weight of the insulation layer to be transferred to the exterior wall through the anchor, increasing the firmness and safety of the insulation installation. The building's ground floor is equipped with horizontal water collection pipes. The pipes are sloped according to the actual conditions, and the bottom of the slope is equipped with a drain outlet that leads directly to the outdoor air or drainage system. The bottom of the drain outlet should be directly connected to the atmosphere to avoid negative pressure and backflow.

Images