Wall structure with adjustable heat transfer coefficient, environment bin and application of environment bin

Abstract

The invention relates to a heat transfer coefficient adjustable wall structure, an environment bin and application, and aims to solve the technical problems that the heat transfer coefficient of a wallboard of an existing environment bin is difficult to adjust and the heat storage performance is insufficient. The wall structure with the adjustable heat transfer coefficient comprises a main body wall and a heat preservation layer arranged on the outer side of the main body wall in a surrounding mode, the heat preservation layer comprises a vacuum insulation plate layer with the vacuum degree adjustable in a vacuum layer, and the heat transfer coefficient of the main body wall is controlled to be within the upper critical value Kwall of the needed heat transfer coefficient change range. The vacuum degree of the vacuum layer is regulated and controlled to change the equivalent heat transfer coefficient of the wall body structure; the equivalent heat transfer coefficient of the environment bin wall body is changed by changing the vacuum degree of the vacuum layer, and specific enclosure structure boundary conditions corresponding to different carbon reduction targets such as low carbon, near zero carbon and zero carbon of the environment bin wall body are achieved, so that experimental research under different carbon reduction targets is supported.

Description

Technical Field

[0001] The present invention relates to the technical field of energy conservation and consumption reduction, and particularly relates to a wall structure with adjustable heat transfer coefficient, an environmental chamber and their applications. Background Art

[0002] Global warming is mainly caused by the excessive emission of greenhouse gases (especially carbon dioxide, etc.). Such climate change has led to the frequent occurrence of extreme climate events, such as heavy rain, drought and heat wave, which have caused serious impacts on the ecosystem, social economy and human life. In order to control the rise of global temperature within a safe range, it is crucial to reduce carbon emissions. The building field, as one of the main sources of carbon emissions, has a huge carbon footprint; therefore, it is particularly urgent to promote zero-carbon buildings. However, to achieve the wide application of zero-carbon buildings, in-depth adaptability research must be carried out according to the characteristics of local energy supply and climate conditions; among them, the heat transfer coefficient of the envelope structure is closely related to the energy consumption level of the building, and energy consumption is one of the main sources of building carbon emissions. Testing the efficiency of different energy systems through the construction of an environmental chamber is one of the important research means to improve zero-carbon building technology.

[0003] Currently, cold storage panels are often used in the construction of environmental chambers; and cold storage panels are a common type of sandwich panel for rapid construction, composed of color steel plates and polyurethane insulation cores. They have the characteristics of light weight, good heat insulation performance and rapid construction, and to a certain extent, they meet the requirements of the environmental chamber for temperature control. However, at the same time, in combination with the research needs of zero-carbon buildings, such wall panels have the following problems: ① The flexibility of the heat transfer coefficient is insufficient. The heat transfer coefficient of traditional cold storage sandwich panels is fixed and difficult to change once fabricated or constructed; this leads to the need to build multiple environmental chambers with different insulation layer thicknesses to meet different heat transfer coefficient requirements when facing the needs of environmental chambers with multiple different carbon reduction targets; thus, not only does it increase the construction cost, put forward higher requirements for the experimental space, but also wastes resources; ② The heat storage performance is insufficient. The composition of cold storage sandwich panels determines that they have good heat insulation effects, but at the same time, their heat storage capacity is seriously insufficient, which is seriously inconsistent with the heat storage and insulation characteristics of the envelope structure of actual buildings, and cannot reflect the actual thermal performance of building envelope structures under different carbon reduction targets. In actual buildings, the heat storage performance of walls plays an important role in regulating the fluctuation of indoor temperature, while the envelope structure of traditional environmental chambers cannot achieve this function.

[0004] The information disclosed in this background art section is only for enhancing the understanding of the background art of the present disclosure, and should not be regarded as an admission or any form of suggestion that this information constitutes the prior art known to those skilled in the art. Summary of the Invention

[0005] In view of at least one of the above technical problems, the present disclosure provides a wall structure with adjustable heat transfer coefficient, an environmental chamber and an application, by controlling the vacuum degree of the vacuum layer in the enclosure structure of the environmental chamber wall, thereby controlling the thermal resistance of the vacuum layer, and further realizing the active regulation of its equivalent heat transfer coefficient.

[0006] According to one aspect of the present disclosure, there is provided a wall structure with adjustable heat transfer coefficient, including a main wall and a heat insulation layer disposed outside the main wall. The heat insulation layer is a vacuum insulation panel layer with adjustable vacuum degree inside the vacuum layer, and the heat transfer coefficient of the main wall is controlled at the upper critical value of the required heat transfer coefficient change range. K wall The vacuum degree of the vacuum layer is regulated to change the equivalent heat transfer coefficient of the wall structure.

[0007] In some embodiments of the present disclosure, a valve communicating with the vacuum layer is installed at a corresponding position of the vacuum insulation panel layer to realize the adjustment and control of the vacuum degree inside the vacuum layer.

[0008] In some embodiments of the present disclosure, a sealing layer is laid between the main wall and the vacuum insulation panel layer to ensure the airtightness of the outer surface of the main wall.

[0009] In some embodiments of the present disclosure, the sealing layer is a PET film layer, which is sealed with silicone sealant, and a slot / spline is used for auxiliary sealing at the contact part between the PET film layer and the vacuum insulation panel layer.

[0010] The PET film has good sealing performance, can effectively block the penetration of external gas molecules, and maintain the vacuum environment of the vacuum layer. At the same time, it also has high transparency, flexibility and chemical stability, and can maintain good physical properties in a vacuum state.

[0011] In some embodiments of the present disclosure, the material of the vacuum insulation panel layer is any one of tempered glass, steel plate, aerogel material, polyvinyl chloride.

[0012] In some embodiments of the present disclosure, a cement mortar coating with a heat transfer coefficient of 1.5~2W / (m 2 •k) is laid on the inner surface or / and the outer surface of the main wall.

[0013] In some embodiments of the present disclosure, the vacuum degree of the vacuum layer is determined by the following method: (1) Set the heat transfer coefficients required for the enclosure structure under different carbon reduction targets such as low carbon, near zero carbon, and zero carbon. K wall ; (2) Determine the thermal resistance of the vacuum layer by the following formula R 0 : ; In the formula, R i ，R e are the heat transfer resistances of the inner and outer surfaces of the wall respectively. Among them, R i = 0.11, R e = 0.04; is the thickness of each layer structure; is the heat transfer coefficient of each layer structure; (3) The required vacuum degree to be adjusted and set is obtained from the thermal resistance R0 of the vacuum layer. The vacuum degree is R 0 ×100%. The relationship between the thermal resistance and the vacuum degree can be referred to the following ranges: vacuum degree 10% - 20%, thermal resistance 0.1 - 0.2 m²•K / W; vacuum degree 20% - 30%, thermal resistance 0.2 - 0.3 m²•K / W; vacuum degree 30% - 40%, thermal resistance 0.3 - 0.4 m²•K / W; vacuum degree 40% - 50%, thermal resistance 0.4 - 0.6 m²•K / W; vacuum degree 50% - 60%, thermal resistance 0.6 - 0.8 m²•K / W; vacuum degree 60% - 70%, thermal resistance 0.8 - 1.2 m²•K / W; vacuum degree 70% - 80%, thermal resistance 1.2 - 1.6 m²•K / W; vacuum degree 80% - 90%, thermal resistance 1.6 - 2.2 m²•K / W; vacuum degree 90% - 99%, thermal resistance 2.2 - 3.0 m²•K / W.

[0014] When the vacuum degree of the vacuum layer increases, the air molecules in the vacuum layer gradually decrease, and the heat convection in the wall gradually decreases, thereby reducing the heat transfer efficiency. Therefore, by changing the vacuum degree of the vacuum layer, the number and activity degree of the remaining gas molecules are affected, thereby affecting the heat transfer, further affecting the thermal resistance of the wall, and finally reducing the heat transfer coefficient. Through the above formula, according to the required heat transfer coefficient of the wall in the experiment, the required thermal resistance of the vacuum insulation layer can be calculated, and further the vacuum degree of the vacuum insulation board layer can be obtained from the thermal resistance of the vacuum layer.

[0015] According to the second aspect of the present disclosure, an environmental chamber is provided, which is enclosed by the wall structure with adjustable heat transfer coefficient.

[0016] According to the third aspect of the present disclosure, the wall structure with adjustable heat transfer coefficient is applied to the construction of an environmental chamber or a carbon emission reduction / zero-carbon building.

[0017] One or more technical solutions provided in the embodiments of the present disclosure have at least any one of the following technical effects or advantages: 1. It can actively and precisely control the heat transfer coefficient of the wall, thus greatly improving the experimental efficiency. When conducting research on the heating and ventilation system in cold northern regions, the heat transfer coefficient of the wall can be set to a lower value to simulate a wall with good insulation performance, and then it can more effectively explore the specific ways in which the heating and ventilation system maintains a comfortable indoor temperature under low outdoor temperature conditions. By flexibly adjusting the heat transfer coefficient of the wall, it is possible to simulate the heat transfer situations of various building types, from old buildings with poor insulation performance (high K value) to new energy-saving buildings (low K value), and then provide accurate and reliable data support for the design of heating and ventilation systems for different building types, strongly promoting the optimization and development of heating and ventilation system design, and enhancing its adaptability and energy efficiency performance in different building scenarios.

[0018] 2. In the face of diversified carbon reduction target scenarios, the building envelope with variable heat transfer coefficient characteristics demonstrates a high degree of flexibility advantages. Given that different climate conditions and building functions have different requirements for the thermal performance of the building envelope, compared with traditional environmental chambers, the building envelope that can adjust the heat transfer coefficient can simulate a variety of different working conditions in the same chamber. In this way, there is no need to repeatedly build multiple experimental chambers due to different carbon reduction target settings and experimental condition requirements, thus effectively saving a lot of resources, including funds, sites, and time, etc., and greatly improving the utilization efficiency of experimental resources.

[0019] 3. Compared with the building materials used in traditional environmental chambers, in this invention, the main wall is selected from the wall materials commonly used in the current construction field, and such materials have a certain heat storage capacity. This characteristic is consistent with the performance of the actual building envelope in heat storage and insulation, so it can more accurately reflect the actual thermal performance of the building envelope under different carbon reduction target requirements. Description of the Drawings

[0020] Figure 1 It is a schematic diagram of the wall structure of the variable heat transfer coefficient environmental chamber in an embodiment of this application.

[0021] Figure 2 It is a schematic diagram of the front structure of the wall of the variable heat transfer coefficient environmental chamber in an embodiment of this application.

[0022] In the above figures, 1 is the vacuum insulation board layer; 2 is the vacuum layer; 3 is the coating on the outer surface of the main wall; 4 is the main wall; 5 is the coating on the inner surface of the main wall; 6 is the vacuum layer support structure; 7 is the thin film vacuum gauge; 8 is the intake valve. Detailed Embodiments

[0023] To better understand the technical solutions of this application, the above technical solutions will be described in detail below in combination with the drawings in the specification and specific embodiments. Embodiment

[0024] This example discloses a wall structure with adjustable heat transfer coefficient. Refer to Figures 1 - 2 , including a main wall 4 and a heat insulation layer surrounding the outside of the main wall. The heat insulation layer is a vacuum insulation panel layer 1 with adjustable vacuum degree in the vacuum layer 2, and an air inlet valve 8 and a thin film vacuum gauge 7 are installed on the vacuum insulation panel layer 1.

[0025] The main wall 4 has stable structural performance and can withstand various loads that may occur during the experiment (such as its own gravity, equipment load, and vacuum panel installation load, etc.). It should have an appropriate heat transfer coefficient (the heat transfer coefficient is controlled within the upper critical value of the heat transfer coefficient change range required for the experiment K wall ), to meet the requirements of the experiment for the heat transfer coefficient. For environmental chambers that require low-carbon, near-zero-carbon, and zero-carbon heat transfer coefficients, according to the "Zero-Carbon Building Technology Standard", the heat transfer coefficient change range of the exterior wall of a low-carbon building is 0.2 - 0.25 W / (m 2 •k), the heat transfer coefficient change range of the exterior wall of a near-zero-carbon building is 0.18 - 0.2 W / (m 2 •k), and the heat transfer coefficient change range of the exterior wall of a zero-carbon building is 0.15 - 0.18 W / (m 2 •k).

[0026] The thermal resistance of the environmental chamber mainly comes from the main wall 4 and the vacuum layer 2. In order to accurately control the heat transfer coefficient of the wall, the heat transfer coefficient of the main wall 4 is controlled at about 0.25 W / (m 2 •k), that is, aerated concrete blocks with a heat transfer coefficient of 0.15 W / (m 2 •k) and a thickness of 0.12 m are used, a cement mortar coating 5 with a heat transfer coefficient of 1.8 W / (m 2 •k) and a thickness of 0.015 m is laid on the inner surface of the main wall 4, and a cement mortar coating 3 with a heat transfer coefficient of 1.8 W / (m 2 •k) and a thickness of 0.02 m is laid on the outer surface of the main wall 4. The thermal resistance of the vacuum layer is determined by the following formula R 0 : ; In the formula, K wall is the heat transfer coefficient of the wall, W / (m 2 •k), and the main structural materials and heat transfer coefficient of the wall are controlled to reach the upper limit of the heat transfer coefficient of the wall required for the experiment, which can be changed according to the experiment requirements (not only for the low-carbon, zero-carbon, and near-zero-carbon experiment ranges, but also for other experiments that require changing the heat transfer coefficient of the wall); R i , R eThey are the heat transfer resistances of the inner and outer surfaces, in W / (m•k). Since the structural wall uses common building materials, which is closer to actual buildings, the heat transfer coefficients of the inner and outer surfaces of the structure can be determined based on the "Code for Thermal Design of Civil Buildings" GB 50176. Usually, the heat transfer resistance of the inner surface of the peripheral enclosure structure can be taken as R i = 0.11 m 2 k / W, and the heat transfer resistance of the outer surface can be taken as R e = 0.04 m 2 k / W; is the thickness of each layer of the wall, in m; is the heat transfer coefficient of each layer of the structure, in W / (m 2 •k). For materials using common building materials such as aerated concrete, the heat transfer coefficient is 0.15 W / (m 2 •k); R 0 is the heat transfer resistance of the vacuum layer, in W / (m•k).

[0027] From the heat transfer resistance of the vacuum layer R 0 the required regulated vacuum degree is obtained. The vacuum degree is R 0 × 100%. The relationship between the heat transfer resistance and the vacuum degree can be referred to the following ranges: vacuum degree 10% - 20%, heat transfer resistance 0.1 - 0.2 m²•K / W; vacuum degree 20% - 30%, heat transfer resistance 0.2 - 0.3 m²•K / W; vacuum degree 30% - 40%, heat transfer resistance 0.3 - 0.4 m²•K / W; vacuum degree 40% - 50%, heat transfer resistance 0.4 - 0.6 m²•K / W; vacuum degree 50% - 60%, heat transfer resistance 0.6 - 0.8 m²•K / W; vacuum degree 60% - 70%, heat transfer resistance 0.8 - 1.40 m²•K / W; vacuum degree 70% - 80%, heat transfer resistance 1.2 - 1.6 m²•K / W; vacuum degree 80% - 90%, heat transfer resistance 1.6 - 2.2 m²•K / W; vacuum degree 90% - 99%, heat transfer resistance 2.2 - 3.0 m²•K / W.

[0028] Use materials with good airtightness and high strength (such as tempered glass, steel vacuum insulation panel layer, aerogel material, polyvinyl chloride, etc.) as the vacuum insulation panel layer 1, which encloses with the main wall 4 to form a vacuum layer 2. The thickness of the vacuum layer 2 is 0.1 m. The heat transfer coefficient is controlled by changing the vacuum degree of the vacuum layer 2: Changing the vacuum degree of the vacuum layer 2 will affect the number and activity degree of the remaining gas molecules, thereby affecting heat transfer, further affecting the increase of the thermal resistance of the main wall 4, and ultimately affecting the heat transfer coefficient of the main wall 4. For example, when the vacuum layer 2 is 10 cm, the thermal resistance change range is from 0.19 W / (m•k) to 2.25 W / (m•k) with the vacuum degree from 0 to 100. When the vacuum degree is 10%, the thermal resistance of the vacuum layer 2 is 0.19 W / (m•k), and at this time the heat transfer coefficient of the environmental chamber wall is 0.239 W / (m 2 •k); when the vacuum height is 70%, the thermal resistance of the vacuum layer 2 is 1.37 W / (m•k), and at this time the heat transfer coefficient of the environmental chamber wall is 0.186 W / (m 2 •k); when the vacuum height is 80%, the thermal resistance of the vacuum layer 2 is 1.58 W / (m•k), and at this time the heat transfer coefficient of the environmental chamber wall is 0.152 W / (m 2 •k).

[0029] An intake valve 8 communicating with the vacuum layer 2 is installed at the corresponding position of the vacuum insulation panel layer 1 to realize the adjustment and control of the vacuum degree in the vacuum layer 2. The vacuum degree of the vacuum layer 2 is controlled by a portable vacuum pump. During the vacuum pumping process, pay attention to observing the change of the vacuum degree to avoid air leakage. After vacuum pumping, the intake valve 8 needs to be reliably sealed to prevent air from entering again. Due to the existence of the external atmospheric pressure, the vacuum insulation panel layer 1 needs to have sufficient strength to prevent deformation. Therefore, a vacuum layer support structure 6 with transverse supports connecting the vacuum insulation panel layer 1 and the main wall 4 at both ends is arranged inside the vacuum layer 2. It can be made of the same material as the vacuum insulation panel layer 1. For example, glass columns are arranged inside the vacuum layer 2 for support, and the distribution of the supports should be reasonable and designed according to the size and shape of the vacuum insulation panel to evenly share the external pressure.

[0030] Meanwhile, a sealing layer is laid between the main body wall 4 and the vacuum insulation panel layer 1 to ensure the airtightness of the outer surface of the main body wall. The sealing layer is a polyethylene terephthalate (PET) film layer, which has good sealing performance and can effectively block the penetration of gas molecules to maintain the vacuum environment. At the same time, it also has high transparency, flexibility and chemical stability, and can maintain good physical properties under vacuum conditions. During installation, attention should be paid to the sealing between the main body wall 4 and the polyethylene terephthalate (PET) film layer. Silicone sealant is used. When applying the sealant, it is necessary to ensure that the sealant is uniform and continuous, avoiding gaps or bubbles, and the sealant should have good adhesion to the selected vacuum insulation panel layer 1 and polyethylene terephthalate (PET) film material. In addition, at the contact part of the vacuum insulation panel layer 1 and the polyethylene terephthalate (PET) film layer, structures such as grooves and tenon-mortise are used to assist in sealing to enhance the sealing effect.

[0031] The intake valve 8 is located at the edge of the vacuum insulation panel layer 1 or a relatively flat position on the side. During installation, insert the intake valve 8 into the hole and firmly install the intake valve 8 on the vacuum insulation panel layer 1 by threaded connection or other fixing methods (such as bolt fixing). During the connection process, pay attention to whether the direction of the intake valve 8 is correct to ensure that it can normally control the gas inlet and outlet. After the connection is completed, check the sealing situation again. A small amount of sealant can be applied to further enhance the sealing effect.

[0032] The thin-film vacuum gauge 7 can display the vacuum degree of the vacuum layer 2. The installation methods include flange method or direct adsorption method. If it is flange connection, a flange interface needs to be installed on the vacuum insulation panel layer 1. Align the flange of the thin-film vacuum gauge 7 with the flange on the vacuum insulation panel layer 1, connect and tighten with bolts, and at the same time place a suitable sealing gasket, such as a rubber gasket or a metal wound gasket, between the flange sealing surfaces to ensure the sealing of the connection. For direct adsorption installation, first clean the surface of the vacuum insulation panel layer 1, then closely attach the adsorption part of the thin-film vacuum gauge 7 to the vacuum insulation panel layer 1, and turn on the adsorption function of the thin-film vacuum gauge 7 to make it firmly adsorbed on the vacuum insulation panel layer 1. The intake valve 8 and the thin-film vacuum gauge 7 should be installed on the vacuum insulation panel layer 1 when it leaves the factory.

[0033] Although some preferred embodiments of the present invention have been described, those skilled in the art can make additional changes and modifications once they know the basic creative concept. Therefore, the appended claims are intended to be construed to include the preferred embodiments and all changes and modifications falling within the scope of this application.

[0034] Obviously, those skilled in the art can make various changes and modifications to the present disclosure without departing from the spirit and scope of its inventive concept. Thus, if these modifications and variations to the present disclosure fall within the scope of the claims of this application and their equivalent technologies, this application also intends to include these changes and modifications therein.

Claims

1. A wall structure with adjustable heat transfer coefficient, comprising a main wall and an insulation layer arranged outside the main wall, characterized in that: The thermal insulation layer includes a vacuum insulation board layer with adjustable vacuum degree in the vacuum layer, and the heat transfer coefficient of the main wall is controlled within the upper critical value of the required heat transfer coefficient variation range. K wall , regulating the vacuum degree of the vacuum layer to change the equivalent heat transfer coefficient of the wall structure.

2. The heat transfer system adjustable wall structure according to claim 1, characterized in that: A valve connected to the vacuum layer is installed at a corresponding position of the vacuum insulation panel layer to achieve regulation and control of the vacuum degree in the vacuum layer.

3. The heat transfer system adjustable wall structure according to claim 1, characterized in that: A sealing layer is provided between the main body wall and the vacuum insulation board layer to ensure the air tightness of the outer surface of the main body wall.

4. The heat transfer system adjustable wall structure according to claim 3, characterized in that: The sealing layer is a PET film layer, which is sealed by silicone sealant, and a groove / mortise and tenon joint is used for auxiliary sealing at the contact portion between the PET film layer and the vacuum insulation board layer.

5. The heat transfer system adjustable wall structure according to claim 1, characterized in that: The vacuum insulation panel layer is made of at least one of tempered glass, steel plate, aerogel material and polyvinyl chloride.

6. The heat transfer system adjustable wall structure according to claim 1, characterized in that: The inner surface and / or outer surface of the main wall is coated with a heat transfer coefficient of 1.5-2W / (m 2 •k) Cement mortar coating.

7. The heat transfer system adjustable wall structure according to claim 1, characterized in that: The vacuum degree of the vacuum layer is determined by the following method: (1) Setting the heat transfer coefficient required for the enclosure structure under different carbon reduction targets such as low carbon, near zero carbon, and zero carbon K wall ; (2) Determine the thermal resistance of the vacuum layer by the following formula: R 0 : ； In the formula, R i ，R e are the heat transfer resistance of the inner and outer surfaces of the wall respectively; is the thickness of each layer structure; is the heat transfer coefficient of each layer structure; (3) Thermal resistance of vacuum layer R 0 The vacuum degree that needs to be adjusted is obtained. R 0 ×100%.

8. An environmental chamber, characterized in that: It is enclosed by the adjustable wall structure of the heat transfer system described in claim 1.

9. Application of the heat transfer coefficient adjustable wall structure according to claim 1 in the construction of environmental warehouses or carbon emission reduction / zero carbon buildings.

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