A thin and light thermal insulation exterior wall applicable to nearly zero energy consumption buildings in severe cold regions

Abstract

A thin and lightweight thermal insulation exterior wall applicable to nearly zero - energy buildings in frigid regions belongs to the field of energy - saving for nearly zero - energy buildings. The exterior wall includes an outer leaf panel, an air flow channel, a thermal insulation layer, and an inner leaf panel, and the exterior wall is connected to the original fresh - air heat recovery device of the nearly zero - energy building; the air flow channel includes a channel inlet, a cavity, and a channel outlet, and the cavity is located between the outer leaf panel and the thermal insulation layer; the channel inlet is below the outer leaf panel; the channel outlet is above the inner leaf panel; the intake pipe of the original fresh - air heat recovery device of the nearly zero - energy building is connected to the channel outlet, and the exhaust pipe of the fresh - air heat recovery device passes through the wall and directly leads to the outdoor environment. The present invention reduces the heat transfer coefficient of the exterior wall through the idea of fresh - air heat recovery, and integrates pre - heating technology, heat - exchange technology, and heat - recovery technology, so that the exterior wall has the characteristics of small thickness, light weight, dynamically adjustable heat transfer coefficient, and can simultaneously meet the fresh - air consumption and fresh - air pre - heating requirements of the building, and improve the heat - recovery efficiency of building exhaust gas.

Description

Technical Field

[0001] The present invention belongs to the field of energy conservation in nearly zero - energy buildings, and particularly relates to a thin and light thermal insulation exterior wall applicable to nearly zero - energy buildings in severe cold regions. Background Art

[0002] Nearly zero - energy buildings are an important measure to achieve energy conservation and emission reduction. For nearly zero - energy buildings in severe cold regions, high requirements are imposed on the thermal insulation and heat insulation performance of exterior walls. To meet this requirement, the thickness of conventional thermal insulation materials often reaches about 350 mm. The overly thick thermal insulation materials lead to problems such as a large amount of raw material consumption, unfavorable transportation and assembly of exterior walls, increased difficulty in the design of the main building structure, and reduction of the building's usable area.

[0003] To solve this problem, researchers have tried to use thermal insulation materials with lower thermal conductivity. However, existing thermal insulation materials with lower thermal conductivity have problems such as high cost or poor durability, and cannot be widely applied in engineering practice. For example, aerogel has a low thermal conductivity, but its high cost limits its application; although the cost of vacuum insulation panels is acceptable in the market, their poor durability makes them unable to be applied in engineering practice. Summary of the Invention

[0004] Based on the problems that the exterior wall thickness of nearly zero - energy buildings in severe cold regions is overly thick (caused by the overly thick thermal insulation layer), which in turn leads to problems such as a large amount of raw material consumption, unfavorable transportation and assembly of exterior walls, increased difficulty in the design of the main building structure, and reduction of the building's usable area, the present invention proposes a thin and light thermal insulation exterior wall applicable to nearly zero - energy buildings in severe cold regions. This exterior wall not only reduces the wallboard thickness but also improves the fresh - air pre - heating efficiency and enhances the waste - gas heat - recovery capacity. Specifically, the present invention reduces the heat transfer coefficient (i.e., the thermal insulation and heat insulation ability) of the exterior wall through the idea of fresh - air heat recovery, and integrates pre - heating technology, heat - exchange technology, and heat - recovery technology, making the exterior wall have the characteristics of small thickness, light weight, dynamically adjustable heat transfer coefficient, and simultaneously meeting the fresh - air consumption and fresh - air pre - heating requirements of the building, and improving the waste - gas heat - recovery efficiency of the building.

[0005] To achieve the above - mentioned objectives, the technical solutions adopted by the present invention are as follows:

[0006] A thin and light thermal insulation exterior wall applicable to nearly zero - energy buildings in severe cold regions, the exterior wall comprising an outer leaf board, an air flow channel, a thermal insulation layer, an inner leaf board, a heat - exchange core, a driving device, and an exhaust pipe;

[0007] The air flow channel includes a channel inlet, a cavity, and a channel outlet. The cavity is located between the outer leaf board and the thermal insulation layer. The channel inlet is below the outer leaf board; the channel outlet is above the inner leaf board;

[0008] The heat exchange core includes a boundary layer, a separation layer, and an inner core; the inner core is composed of multiple layers of sheet materials, and there is a gap of 8 - 15 mm between adjacent sheet materials, which serves as the channel for air flow to enter and exit the heat exchange core; heat exchange cores need to be arranged at both the inlet and outlet of the duct; the separation layer divides the heat exchange core into two spaces, an air inlet side and an exhaust side, so that the outdoor incoming air flow is separated from the indoor exhaust air flow.

[0009] The driving device is installed on the side of the heat exchange core (at the duct outlet) close to the indoor environment. The driving device is assembled by 2 fans, and the fans rotate in opposite directions to drive the incoming air flow and the exhaust air flow respectively.

[0010] The exhaust duct is connected to the exhaust sides of the two heat exchange cores at the duct inlet and the duct outlet.

[0011] A thin and lightweight thermal insulation exterior wall applicable to nearly zero - energy buildings in severe cold regions. The exterior wall includes an outer leaf board, an air flow duct, a thermal insulation layer, and an inner leaf board, and this exterior wall is connected to the original fresh - air heat recovery device of the nearly zero - energy building.

[0012] The air flow duct includes a duct inlet, a cavity, and a duct outlet. The cavity is located between the outer leaf board and the thermal insulation layer; the duct inlet is below the outer leaf board; the duct outlet is above the inner leaf board.

[0013] The intake pipe of the original fresh - air heat recovery device of the nearly zero - energy building is connected to the duct outlet, and the exhaust pipe of the fresh - air heat recovery device passes through the wall and leads directly to the outdoor environment.

[0014] The beneficial effects of the present invention compared with the prior art are as follows:

[0015] (1) Significantly reduce the thickness of the exterior wall and make it lightweight. By setting the air flow duct, using the air flow to recover heat and reducing the thermal radiation in the cavity to reduce the heat transfer coefficient of the exterior wall, it solves the limitation of the prior art that relies on increasing the thickness of the thermal insulation layer to reduce the heat transfer coefficient, and thus achieves the goal of significantly reducing the thickness of the wall panel.

[0016] (2) It can simultaneously solve the indoor fresh - air demand. Due to the high airtightness of nearly zero - energy buildings, a fresh - air system needs to be configured to meet the indoor fresh - air demand of the human body. The idea of using the air flow to recover heat in the present invention is equivalent to changing the inlet channel of the fresh - air system to the air flow duct of the exterior wall, and realizing the exchange of outdoor fresh air and indoor exhaust gas through the wall. While achieving a low heat transfer coefficient of the exterior wall, it also solves the indoor fresh - air demand.

[0017] (3) It has stronger heat insulation ability, and the heat transfer coefficient can be regulated. The heat transfer coefficient of the present invention is determined by the air flow rate. As the air flow rate increases, the heat transfer coefficient gradually decreases. Moreover, the surface of the cavity wall is specially designed with an extremely low thermal radiation emissivity. When the air flow rate exceeds a certain level, the heat transfer coefficient can approach 0, which means it has stronger heat insulation ability compared with the existing exterior walls. Additionally, when the outdoor environment is beneficial to comfort (such as the free cool air outdoors on summer nights and solar radiation gain), the present invention can adjust the air flow rate to change the heat transfer coefficient of the exterior wall, thereby efficiently utilizing the free energy in the outdoor environment and achieving the purpose of energy conservation.

[0018] (4) The overall building energy consumption is smaller compared with the existing ultra-low energy consumption buildings. In the existing ultra-low energy consumption building fresh air systems, heat exchange is only carried out at one place, and the preheating degree of the fresh air is limited, and there will still be a large amount of heat (cold) loss. However, the present invention innovatively proposes to carry out heat exchange at the two places with the largest temperature difference (the inlet and the outlet) respectively. It has been proved by experiments that this method can significantly improve the fresh air preheating efficiency and the waste gas heat recovery efficiency, and thus make the overall building energy consumption smaller.

[0019] (5) The energy consumption is significantly reduced compared with the existing breathing walls. First, the surfaces of the outer leaf panel and the insulation layer in contact with the cavity are specially treated, and their thermal radiation emissivities are very low, which greatly reduces the energy loss caused by thermal radiation. Second, the cavity is located between the outer leaf panel and the insulation layer. Due to the large thermal resistance of the insulation layer, the air flow will not significantly increase the amplitude of the indoor heat transfer to the outdoor, thereby ensuring the stability of the indoor heat and reducing the energy consumption. Third, the present invention conducts heat exchange through the heat exchange core, which can fully preheat the fresh air and recover the heat of the indoor waste gas, and the energy-saving effect is obvious. Description of the Drawings

[0020] Figure 1 It is a three-dimensional schematic diagram of the lightweight heat-insulating exterior wall;

[0021] Figure 2 It is the front view of the heat-insulating exterior wall in the first specific embodiment;

[0022] Figure 3 It is for Figure 2 the C-C sectional view in

[0023] Figure 4 It is for Figure 2 the D-D sectional view in

[0024] Figure 5 It is a three-dimensional schematic diagram of the heat exchange core;

[0025] Figure 6 It is a three-dimensional schematic diagram of the driving device;

[0026] Figure 7 It is the front view of the heat-insulating exterior wall in the sixth specific embodiment;

[0027] Figure 8 is Figure 7 the sectional view A-A of

[0028] Figure 9 is Figure 7 the sectional view B-B of

[0029] Figure 10 is the wall heat transfer coefficient diagram of Example 1;

[0030] Figure 11 is the wall heat transfer coefficient diagram of Example 2. Detailed implementation manners

[0031] The technical solutions of the present invention will be further described below in conjunction with the accompanying drawings and embodiments, but are not limited thereto. Any modification or equivalent replacement of the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention shall be covered by the protection scope of the present invention.

[0032] Detailed implementation manner 1: What is described in this implementation manner is a thin and light thermal insulation exterior wall applicable to nearly zero energy consumption buildings in severe cold regions. As Figures 1 - 6 shown, the exterior wall includes an outer leaf board 1, an air flow channel 2, a thermal insulation layer 3, an inner leaf board 4, a heat exchange core 5, a driving device 6 and an exhaust duct 7;

[0033] The air flow channel 2 includes a channel inlet 8, a cavity 9 and a channel outlet 10. The cavity 9 is located between the outer leaf board 1 and the thermal insulation layer 3. The channel inlet 8 is below the outer leaf board 1; the channel outlet 10 is above the inner leaf board 4;

[0034] The heat exchange core 5 includes a boundary layer 11, a partition layer 12 and an inner core 13; the inner core 13 is composed of multiple layers of sheet materials, and the gap between adjacent sheet materials is 8-15 mm, which is the channel for air flow to enter and exit the heat exchange core 5; heat exchange cores 5 need to be arranged at both the channel inlet 8 and the channel outlet 10; the partition layer 12 divides the heat exchange core 5 into two spaces, an intake side 14 and an exhaust side 15, so that the outdoor intake air flow and the indoor exhaust air flow are separated; the inner core needs to have a sufficiently high thermal conductivity, and the air between the layers of the inner core cannot penetrate each other;

[0035] The driving device 6 is installed on the side of the heat exchange core 5 (at the channel outlet 10) close to the indoor environment. There is no driving device 6 at the heat exchange core 5 (at the channel inlet 8). The driving device 6 is assembled by 2 fans, and the fans rotate in opposite directions to drive the intake air flow and the exhaust air flow respectively.

[0036] The exhaust duct 7 is connected to the exhaust sides 15 of the two heat exchange cores 5 at the channel inlet 8 and the channel outlet 10. That is, the exhaust side 15 is connected to the exhaust duct 7, and the intake side 14 is connected to the air flow channel.

[0037] Embodiment 2: A thin and light thermal insulation exterior wall applicable to nearly zero - energy buildings in severe cold regions as described in Embodiment 1, where the thickness of the cavity 9 is 40 - 55 mm.

[0038] Embodiment 3: A thin and light thermal insulation exterior wall applicable to nearly zero - energy buildings in severe cold regions as described in Embodiment 1, where the thermal conductivity of the materials of the boundary layer 11 and the partition layer 12 needs to be less than 0.2 W / (m·K), the thermal conductivity of the material of the inner core 13 needs to be greater than 200 W / (m·K), and the boundary layer 11, the partition layer 12, and the inner core 13 must have oxidation - resistance and rust - resistance capabilities.

[0039] Embodiment 4: A thin and light thermal insulation exterior wall applicable to nearly zero - energy buildings in severe cold regions as described in Embodiment 1. The distance between the inlets 8 of two adjacent channels (or the distance between the outlets 10 of the channels) is less than 21 times the width of the inlet 8 of the channel (or the width of the outlet 10 of the channel). The distance between the inlets of the channels should not be too large. If the distance is large, vortices will be formed, which will reduce the heat recovery efficiency and increase the energy consumption of the driving device, resulting in more energy losses.

[0040] Embodiment 5: A thin and light thermal insulation exterior wall applicable to nearly zero - energy buildings in severe cold regions as described in Embodiment 1. The thermal radiation emissivity of the surface of the outer leaf board 1 in contact with the cavity must be less than 0.2, and the thermal radiation emissivity of the surface of the thermal insulation layer 3 in contact with the cavity must be less than 0.15. This can be achieved by pasting polished iron sheets, polished aluminum foils, or asbestos papers on the surface.

[0041] The technical process of the present invention:

[0042] Fresh air flow: The driving device 6 forms a pressure difference, driving outdoor fresh air to enter from the inlet 8 of the channel, flowing through the intake side 14 of the heat exchange core 5 (at the position of the inlet 8 of the channel), the cavity 9, the intake side 14 of the heat exchange core 5 (at the position of the outlet 10 of the channel), the outlet 10 of the channel, and then entering the room.

[0043] Exhaust gas flow: Driving the indoor exhaust gas to enter from the outlet 10 of the channel, flowing through the exhaust side 15 of the heat exchange core 5 (at the position of the outlet 10 of the channel), the exhaust pipe 7, the exhaust side 15 of the heat exchange core 5 (at the position of the inlet 8 of the channel), the inlet 8 of the channel, and then discharging to the outside.

[0044] The technical principle of the present invention:

[0045] (1) The heat dissipated by the exterior wall is brought back into the room through the air flow in the cavity. The greater the air flow rate, the higher the total heat recovery, the less the corresponding heat loss, and thus the lower the heat transfer coefficient of the exterior wall, getting rid of the drawback of relying on increasing the thickness of the thermal insulation layer to reduce the heat transfer coefficient.

[0046] (2) The indoor exhaust gas contains more heat than the fresh air. This heat is recovered through heat exchange when the exhaust gas flows through the heat exchange core, and the heat is transferred to the fresh air. Since the inner core of the heat exchange core has an extremely high thermal conductivity and a large contact area with the air flow, the temperatures of the fresh air and the exhaust gas flowing out after heat exchange through the heat exchange core are nearly the same. By arranging the heat exchange core at the lowest temperature of the fresh air and the highest temperature of the exhaust gas respectively, the heat recovery efficiency of the exhaust gas and the preheating efficiency of the fresh air can be maximally improved.

[0047] (3) The outdoor fresh air undergoes heat exchange through two heat exchange cores and the cavity, which can fully preheat the fresh air. The fresh air entering the room has a relatively high temperature, thus reducing the energy consumption of the indoor heat source.

[0048] Specific Embodiment Six: This embodiment describes a thin and light thermal insulation exterior wall applicable to nearly zero - energy buildings in severe cold regions. As Figures 7 - 9 shown, the exterior wall includes an outer leaf panel 1, an air flow channel 2, a thermal insulation layer 3, and an inner leaf panel 4, and this exterior wall is connected to the original fresh air heat recovery device of the nearly zero - energy building;

[0049] The air flow channel 2 includes a channel inlet 8, a cavity 9, and a channel outlet 10. The cavity 9 is located between the outer leaf panel 1 and the thermal insulation layer 3; the channel inlet 8 is below the outer leaf panel 1; the channel outlet 10 is above the inner leaf panel 4;

[0050] The intake pipe of the original fresh air heat recovery device of the nearly zero - energy building is connected to the channel outlet 10, and the exhaust pipe of the fresh air heat recovery device passes through the wall and directly leads to the outdoor environment.

[0051] Specific Embodiment Seven: For the thin and light thermal insulation exterior wall applicable to nearly zero - energy buildings in severe cold regions described in Specific Embodiment Six, the thickness of the cavity 9 is 40 - 55 mm.

[0052] Specific Embodiment Eight: For the thin and light thermal insulation exterior wall applicable to nearly zero - energy buildings in severe cold regions described in Specific Embodiment Six, the distance between two adjacent channel inlets 8 (or the distance between two adjacent channel outlets 10) is less than 21 times the width of the channel inlet 8 (or the width of the channel outlet 10).

[0053] Specific Embodiment Nine: For the thin and light thermal insulation exterior wall applicable to nearly zero - energy buildings in severe cold regions described in Specific Embodiment Six, the thermal radiation emissivity of the surface of the outer leaf panel 1 in contact with the cavity must be less than 0.2, and the thermal radiation emissivity of the surface of the thermal insulation layer 3 in contact with the cavity must be less than 0.15. This can be achieved by pasting polished iron sheets, polished aluminum foils, or asbestos papers on the surface, etc.

[0054] The technical process of the present invention:

[0055] Fresh air flow: The fresh air heat recovery device creates a pressure difference, driving outdoor fresh air to enter from the duct inlet 8, flowing through the cavity 9, the duct outlet 10, and the fresh air heat recovery device, and entering the room after heat exchange;

[0056] Exhaust gas flow: Indoor exhaust gas enters the fresh air heat recovery device, flows through the heat exchange, and is discharged outdoors through the exhaust pipe.

[0057] Technical principle of the present invention:

[0058] (1) The heat dissipated through the exterior wall is brought back into the room by the air flow in the cavity. Moreover, the greater the air flow rate, the higher the total heat recovery, the less the corresponding heat loss, and thus the lower the heat transfer coefficient of the exterior wall, eliminating the drawback of relying on increasing the thickness of the insulation layer to reduce the heat transfer coefficient.

[0059] (2) Indoor exhaust gas contains more heat than fresh air. This heat is exchanged and recovered when the exhaust gas flows through the fresh air heat recovery device, transferring the heat to the fresh air, thereby achieving the goal of heat recovery. Since the fresh air heat recovery device is an inherent device of a nearly zero - energy - consumption building, the second technical solution will not cause additional driving energy consumption.

[0060] (3) Outdoor fresh air is pre - heated by the fresh air heat recovery device and the cavity. Although the pre - heating degree is slightly worse than that of the first technical solution, the fresh air entering the room already has a relatively high temperature, still playing a good role in pre - heating fresh air.

[0061] Example 1:

[0062]

[0063] The distance between adjacent sheet materials in the inner core is 10 mm; the distance between duct inlets: 2.4 m; the vertical distance between the duct inlet and the duct outlet: 3.4 m; on the surface of the outer leaf plate in contact with the cavity, 0.1 - mm polished aluminum foil is pasted, and on the surface of the insulation layer in contact with the cavity, 0.1 - mm asbestos paper is pasted.

[0064] (1) The heat transfer coefficient of the wall of the present invention (as Figure 10 shown):

[0065] If the technology of the present invention is not adopted (i.e., the existing technology is adopted), with the same wall materials and dimensions, the heat transfer coefficient of the wall is 0.83 [W / (m·K)]. However, the heat transfer coefficient of the wall of the present invention is significantly reduced (<0.2 [W / (m·K)]), proving that the present invention (specific embodiment 1) can significantly improve the thermal insulation performance of the exterior wall. When the air flow rate reaches 5 [L / s], the heat transfer coefficient requirement of a nearly zero - energy - consumption exterior wall can be met, while in the existing technology, the EPS insulation layer needs to be increased to at least 270 mm. Therefore, the present invention can significantly reduce the thickness of the exterior wall.

[0066] (2) When the outdoor ambient temperature in the severe cold region is -20°C and the indoor temperature is 18°C, the results of the fresh air preheating temperature and the exhaust gas discharge temperature of the present invention are as follows in the table:

[0067] Flow rate Outdoor fresh air temperature Fresh air preheating temperature Indoor exhaust gas temperature Exhaust gas discharge temperature 1.8 -20℃ 5.33℃ 18℃ -7.33℃ 3.6 -20℃ 5.17℃ 18℃ -7.01℃ 5.4 -20℃ 5.11℃ 18℃ -6.95℃

[0068] In the prior art, when a near-zero energy consumption building adopts a sensible fresh air system, even if the heat exchange efficiency reaches the theoretical maximum value, the results are: the fresh air preheating temperature is -1°C and the exhaust gas discharge temperature is -1°C.

[0069] When the present invention is compared with the prior art: ① The fresh air temperature entering the room of the present invention is higher, indicating that the preheating efficiency of the present invention is higher, and the energy consumed by the indoor heat source to heat the fresh air to the required indoor temperature is lower. Therefore, the present invention helps the fresh air preheating energy saving effect; ② The exhaust gas discharge temperature of the present invention is lower, proving that the exhaust gas heat recovery efficiency of the present invention is higher, and thus the present invention is more energy-saving and emission-reducing.

[0070] Example 2:

[0071] Integrated with the original fresh air heat recovery device in the near-zero energy consumption building

[0072]

[0073] The distance between the inlet holes: 2.4 m; the vertical distance between the inlet and outlet of the holes: 3.4 m; a 0.1 mm polished aluminum foil is pasted on the surface of the outer leaf plate in contact with the cavity, and a 0.1 mm asbestos paper is pasted on the surface of the insulation layer in contact with the cavity.

[0074] The heat transfer coefficient of the same wall in the prior art: 0.83 [W / (m·K)]

[0075] (1) The heat transfer coefficient of the wall of the present invention (as Figure 11 shown):

[0076] If the technology of the present invention is not adopted (prior art), with the same wall material and size, the heat transfer coefficient of the wall is 0.83 [W / (m·K)]. However, the heat transfer coefficient of the wall of the present invention is significantly reduced (<0.18 [W / (m·K)]), proving that the present invention (specific embodiment six) can significantly improve the heat insulation performance of the exterior wall. When the air flow rate reaches 4.6 [L / s], the heat transfer coefficient requirement of the near-zero energy consumption exterior wall can be achieved, while in the prior art, the EPS insulation layer needs to be increased to at least 270 mm. Therefore, the present invention can significantly reduce the thickness of the exterior wall.

[0077] (2) When the outdoor ambient temperature in the severe cold region is -20°C and the indoor temperature is 18°C, the results of the fresh air preheating temperature and the exhaust gas discharge temperature of the present invention are as follows in the table:

[0078] Flow rate Outdoor fresh air temperature Fresh air preheating temperature Indoor exhaust gas temperature Exhaust gas discharge temperature 1.8 -20℃ -0.52℃ 18℃ -0.86℃ 3.6 -20℃ -1.17℃ 18℃ -0.57℃ 5.4 -20℃ -1.31℃ 18℃ -0.44℃

[0079] When a nearly zero - energy consumption building adopts a sensible heat fresh - air system, even if the heat - exchange efficiency reaches the theoretical maximum value, the results are as follows: the pre - heating temperature of the fresh air is - 1°C, and the exhaust gas discharge temperature is - 1°C.

[0080] Compared with the prior art, the fresh - air pre - heating efficiency and the waste - heat recovery efficiency of the present invention basically reach the highest theoretical value of the heat - exchange efficiency of the prior art.

Claims

1. A thin and lightweight thermal insulation exterior wall applicable to nearly zero - energy buildings in severe cold regions, characterized in that: The exterior wall includes an outer leaf panel (1), an air flow channel (2), a thermal insulation layer (3), an inner leaf panel (4), a heat exchange core (5), a driving device (6), and an exhaust duct (7); The air flow channel (2) includes a channel inlet (8), a cavity (9), and a channel outlet (10). The cavity (9) is located between the outer leaf panel (1) and the thermal insulation layer (3). The channel inlet (8) is below the outer leaf panel (1); the channel outlet (10) is above the inner leaf panel (4); The heat exchange core (5) includes a boundary layer (11), a partition layer (12), and an inner core (13); the inner core (13) is composed of multiple layers of sheet materials, and there is a gap of 8 - 15 mm between adjacent sheet materials, which is the channel for air flow to enter and exit the heat exchange core (5); heat exchange cores (5) need to be arranged at both the channel inlet (8) and the channel outlet (10); the partition layer (12) divides the heat exchange core (5) into two spaces, an intake side (14) and an exhaust side (15), so that the outdoor intake air flow and the indoor exhaust air flow are separated; the inner core (13) needs to have a sufficiently high thermal conductivity, and the air between the layers of the inner core (13) cannot penetrate each other; The driving device (6) is installed on the side of the heat exchange core (5) near the indoor environment at the channel outlet (10). The driving device (6) is assembled by 2 fans, and the fans rotate in opposite directions, respectively driving the intake air flow and the exhaust air flow; The exhaust duct (7) is connected to the exhaust sides (15) of the two heat exchange cores (5) at the channel inlet (8) and the channel outlet (10).

2. The thin and lightweight thermal insulation exterior wall applicable to nearly zero - energy buildings in severe cold regions according to claim 1, characterized in that: The thickness of the cavity (9) is 40 - 55 mm.

3. The thin and lightweight thermal insulation exterior wall applicable to nearly zero - energy buildings in severe cold regions according to claim 1, characterized in that: The thermal conductivity of the materials of the boundary layer (11) and the partition layer (12) needs to be less than 0.2 W / (m·K), and the thermal conductivity of the material of the inner core (13) needs to be greater than 200 W / (m·K).

4. The thin and lightweight thermal insulation exterior wall applicable to nearly zero - energy buildings in severe cold regions according to claim 1, characterized in that: The distance between two adjacent channel inlets (8) is less than 21 times the width of the channel inlet (8).

5. The thin and lightweight thermal insulation exterior wall applicable to nearly zero - energy buildings in severe cold regions according to claim 1, characterized in that: The thermal radiation emissivity of the surface of the outer leaf panel (1) in contact with the cavity must be less than 0.2, and the thermal radiation emissivity of the surface of the thermal insulation layer (3) in contact with the cavity must be less than 0.15.

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