A total heat exchanger

Abstract

This utility model belongs to the field of ventilation equipment, specifically relating to a total heat exchanger, including a shell, a heat exchange core, and a fan. The shell contains a fresh air duct and an exhaust air duct. The heat exchange core facilitates heat exchange between indoor exhaust air and outdoor fresh air. The fan drives airflow within the ducts and includes a volute. The volute has an outlet air duct, an upper extension plate, and a lower pressure unit. The upper extension plate is located on the side of the outlet air duct away from the fan axis, and the lower pressure unit is located on the side of the upper extension plate facing the fan axis. The lower pressure unit has a multi-layered stepped structure. When airflow passes through the outlet air duct, it contacts the lower pressure unit and, guided by it, deflects layer by layer along the multi-layered stepped structure. This structure avoids sudden changes in direction, reduces airflow impact and backflow, and lowers aerodynamic noise; it also avoids the interaction between the airflow and the deep volute tongue caused by direct downward pressure from the upper extension section, allowing the airflow to more evenly fill the outlet air duct, reducing airflow attenuation, improving fan efficiency, and enhancing the ventilation performance of the total heat exchanger.

Description

Technical Field

[0001] This application relates to the field of ventilation equipment, and more particularly to a total heat exchanger. Background Technology

[0002] A total heat exchanger is an energy-saving ventilation device that simultaneously replaces indoor and outdoor air while recovering and utilizing the sensible and latent heat carried by the indoor air. It is widely used in various buildings such as residences, office buildings, and shopping malls. By recovering exhaust air energy, it reduces the energy consumption of the air conditioning system while ensuring indoor air freshness. Its main structure includes an outer shell, a heat exchange core, a fresh air duct, an exhaust air duct, a fan, and filter components. The heat exchange core is the core component, where energy exchange between fresh and exhaust air occurs. The fan drives the fresh and exhaust air to flow within their respective ducts, and the filter components purify the incoming fresh air.

[0003] The fan is the core power component of a total heat exchanger. Its main function is to drive airflow through the fresh air and exhaust air ducts inside the equipment, achieving forced air exchange between indoors and outdoors. Its performance directly affects the ventilation efficiency, airflow stability, and energy consumption level of the total heat exchanger. Since total heat exchangers are mostly installed indoors or near living areas, there are specific requirements for the fan: firstly, stable airflow; secondly, low noise to avoid noise pollution to the indoor environment; and thirdly, high static pressure resistance.

[0004] The applicant is aware that the volute structure of a fan typically employs an upper extension section with downward pressure and a deep volute tongue to enhance its static pressure resistance. Specifically, the upper extension section of the volute is usually pressed downwards at a 5-16° angle to reduce the volute outlet area and strengthen its ability to confine airflow. Simultaneously, a deep volute tongue design is used, meaning the volute tongue extends significantly into the volute. This structure aims to improve the fan's static pressure resistance to adapt to the high resistance of the internal airflow duct of the total heat exchanger. However, this typical volute structure has obvious drawbacks: on the one hand, the downward pressure of the upper extension section and the deep volute tongue design will reduce the outlet area of ​​the volute, resulting in a decrease in airflow. To compensate for the airflow loss, the fan speed needs to be increased, but the increase in speed directly leads to an increase in aerodynamic noise, which contradicts the requirement for low noise. On the other hand, the direct downward pressure of the upper extension section and the deep volute tongue can easily form airflow impact, and backflow is likely to occur on the inner walls of both sides of the volute and in the volute tongue area. That is, the direct downward pressure of the upper extension section of the volute causes the airflow to interact with the deep volute tongue, which not only further aggravates aerodynamic noise, but also leads to airflow loss, making it difficult for the fan to maintain a stable airflow in a high static pressure environment, while also consuming additional energy, which conflicts with the requirements for energy saving. Utility Model Content

[0005] This application provides a total heat exchanger, the purpose of which is to reduce airflow attenuation and aerodynamic noise by adopting a stepped down-pressure structure design, while meeting the requirements of static pressure resistance, and ultimately achieving the effect of balancing airflow stability, low noise and energy saving.

[0006] To achieve the above objectives, this application adopts the following technical solution: In a first aspect, a total heat exchanger is provided, comprising: The casing contains a fresh air duct and an exhaust air duct. A heat exchange core is disposed within the housing; it is used to realize heat exchange between indoor exhaust air and outdoor fresh air. A fan, disposed within the housing, is used to drive airflow in the fresh air duct or the exhaust air duct; wherein the fan includes a volute. The volute includes: Air outlet duct, which is used to exhaust airflow; The upper extension plate is the side wall of the air outlet duct, and its plane is parallel to the axis of the fan. It is located on the side of the air outlet duct away from the axis of the fan. A pressure-reducing unit is disposed on the side of the upper extension plate facing the fan shaft, and the pressure-reducing unit includes a multi-layer stepped structure; When the airflow passes through the air outlet duct, it comes into contact with the pressure unit and, guided by the pressure unit, deflects the airflow direction layer by layer along its multi-layered stepped structure.

[0007] Secondly, a total heat exchanger is provided, comprising: The casing contains a fresh air duct and an exhaust air duct. A heat exchange core is disposed within the housing; it is used to realize heat exchange between indoor exhaust air and outdoor fresh air. A fan, disposed within the housing, is used to drive airflow in the fresh air duct or the exhaust air duct; wherein the fan includes a volute. The volute includes: Air outlet duct, which is used to exhaust airflow; The upper extension plate is the side wall of the air outlet duct, and its plane is parallel to the axis of the fan. It is located on the side of the air outlet duct away from the axis of the fan. A pressure unit is disposed on the side of the upper extension plate facing the fan shaft. The pressure unit includes N pressure plates, all of which are attached to the upper extension plate; wherein, N≥3, and N is an integer. Along the direction of airflow discharge, the i-th pressure plate is connected to the (i+1)-th pressure plate; the vertical distance between the windward surface of the i-th pressure plate and the upper extension plate is greater than the vertical distance between the windward surface of the (i+1)-th pressure plate and the upper extension plate; where 1≤i≤N, and i is an integer; The configuration of the pressure unit ensures that when the airflow passes through the air outlet duct, it comes into contact with the pressure unit and, guided by the pressure unit, the airflow direction is deflected layer by layer along its N pressure plates.

[0008] In the above embodiments, the multi-layer stepped downward pressure unit of this application can deflect the airflow layer by layer, avoid sudden airflow turning, effectively reduce airflow impact and backflow, thereby reducing aerodynamic noise; at the same time, by avoiding direct downward pressure on the upper extension section of the volute, which would cause the airflow to interact with the deep volute tongue, the airflow can be more uniform and completely fill the entire air outlet duct, and reduce airflow attenuation, improve fan operating efficiency, thereby improving the overall ventilation performance of the total heat exchanger, ensuring efficient and stable replacement of indoor and outdoor air, achieving better heat exchange effect, and improving indoor air quality.

[0009] In some embodiments of this application, the volute further includes a surrounding plate, and the upper extension plate is connected to the surrounding plate; the upper extension plate is tangent to the surrounding plate at its connection with the surrounding plate, and the upper extension plate extends from its connection with the surrounding plate in the direction of airflow discharge.

[0010] In the above embodiments, the upper extension plate is set along the tangent, which makes the position of the upper extension plate more precise and better fits the spiral structure of the surrounding plate. This provides a reasonable basis for the subsequent setting of the pressure unit, ensuring that the airflow can flow along the designed path when passing through the upper extension plate and the pressure unit. This further optimizes the airflow guidance effect, reduces airflow conflicts and backflow caused by traditional structural designs, and helps to reduce noise and stabilize airflow.

[0011] In some embodiments of this application, the ratio of the projected width of the pressing unit to the projected width of the upper extension plate on a plane perpendicular to the exhaust direction of the airflow is 0.55 to 0.85.

[0012] In the above embodiments, it is possible to ensure that the down-pressure unit fully constrains the airflow, so that the airflow is smoothly deflected layer by layer along the stepped structure, avoiding the problems of insufficient deflection and weakened anti-static pressure capability caused by too small a proportion of the projected width (e.g., <0.55); and it is also possible to prevent excessive obstruction of the air duct caused by too large a proportion (e.g., >0.85), reducing airflow impact and eddy generation. Thus, while improving the anti-static pressure performance, it reduces aerodynamic noise and airflow loss, and takes into account the energy-saving performance and ventilation efficiency stability of the total heat exchanger. It effectively solves the contradiction between anti-static pressure capability and low noise and high airflow requirements in traditional direct down-pressure structures.

[0013] In some embodiments of this application, the pressing unit includes at least three pressure plates; the thickness of the multiple pressure plates increases sequentially along the airflow discharge direction to form a stepped structure.

[0014] In the above embodiments, multiple pressure plates cooperate with each other, allowing the airflow to change direction more smoothly during the layer-by-layer flow process, further avoiding violent airflow impact and backflow phenomena. The stepped structure formed by the combination of pressure plates of different thicknesses enhances the layer-by-layer guiding and turning effect of the airflow, ensuring static pressure resistance while better maintaining airflow stability, improving the operating performance of the fan in high static pressure environments, and ensuring smooth airflow within the total heat exchanger.

[0015] In some embodiments of this application, the thickness difference between any two adjacent pressure plates is 0.5~1 mm.

[0016] In the above embodiments, by defining a specific thickness difference, a reasonable thickness difference allows the airflow to transition smoothly between each layer of pressure plates. This prevents abrupt changes in airflow due to excessive thickness variations, and also avoids insufficient airflow guidance due to insufficient thickness variations. This thickness difference range ensures that the airflow maintains a relatively stable velocity and direction as it adjusts its direction layer by layer between multiple pressure plates, continuously reducing aerodynamic noise, optimizing fan performance, and providing stable airflow conditions for the efficient operation of the total heat exchanger.

[0017] In some embodiments of this application, the thickness of the pressure plate ranges from 1 to 11 mm.

[0018] In the above embodiments, this thickness range can meet the requirements for airflow constraint and guidance under different working conditions, ensuring both the structural strength of the pressure plate itself and effectively guiding the airflow. It also indirectly constrains the number of pressure plates.

[0019] In some embodiments of this application, the connection between two adjacent pressure plates is achieved by rounded corner transition, beveled corner transition, or arc-shaped curved surface transition.

[0020] In the above embodiments, the smooth transition structure can prevent airflow from impacting and separating at the pressure plate connection, allowing airflow to pass through each pressure plate continuously and smoothly, further reducing noise caused by discontinuous airflow, while reducing energy loss, maintaining stable airflow, ensuring efficient operation of the fan, improving the energy utilization efficiency of the total heat exchanger, and helping to achieve energy-saving effects.

[0021] In some embodiments of this application, the pressing unit includes three pressure plates; along the airflow discharge direction, the length ratio of the three pressure plates is 1:2:5.

[0022] In the above embodiments, the specific length ratios allow each pressure plate to exert different degrees of influence on the airflow. Combined with variations in thickness, this enables precise stratified guidance and constraint of the airflow. From the fan axis towards the outlet duct, the shorter pressure plates initially adjust the airflow direction, while the subsequent longer pressure plates not only adjust the airflow direction but also gradually strengthen the control over the airflow. This results in a uniform and stable flow field at the volute outlet, better balancing static pressure resistance, airflow stability, and low noise requirements. This optimizes the aerodynamic performance within the total heat exchanger and improves the overall performance of the equipment.

[0023] In some embodiments of this application, the volute further includes at least two wave units, each of which is disposed on the side of the upper extension plate facing the fan shaft; along the airflow discharge direction, the wave units are disposed at the end of the air outlet duct.

[0024] In the above embodiments, the wave unit can further disrupt and refine the airflow, optimizing the airflow that has been initially adjusted by the pressure unit before it exits the volute. Although the wave unit increases resistance at the outlet duct, it changes the direction of the outlet airflow, disperses any potential local airflow clusters, and makes the upper airflow distribution more uniform, reducing the interaction between the outlet and surrounding structural components, lowering noise by 0.5 dBA; it also enhances the stability of the fan and the ventilation quality of the total heat exchanger, providing a more stable and comfortable fresh air environment indoors.

[0025] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of the overall structure of the total heat exchanger provided in the embodiments of this application; Figure 2 This is a first-view perspective perspective view of the fan provided in the embodiments of this application; Figure 3 This is a second-view perspective perspective view of the fan provided in the embodiments of this application; Figure 4 This is a front view of the volute casing of a traditional wind turbine; Figure 5 This is a first-view perspective perspective view of the volute provided in the embodiments of this application; Figure 6This is a front view of the volute provided in the embodiments of this application; Figure 7 This is a second-view perspective perspective view of the volute provided in the embodiments of this application; Figure 8 yes Figure 7 Enlarged view of part A in the image; Figure 9 This is a schematic diagram of the structure of the pressing unit provided in the embodiment of this application; Figure 10 This is a side view of the volute provided in an embodiment of this application.

[0028] In the above figures: 100, shell; 110, fresh air inlet; 120, return air inlet; 130, exhaust outlet; 140, supply air outlet; 150, heat exchange core; 200, fan; 210, top plate; 211, second opening; 211a, center; 220, enclosure plate; 221, upper extension plate; 221a, wave unit; 222, volute tongue; 223, contour spiral line; 223a, starting end; 223b, ending end; 230, bottom plate; 240, motor; 250, impeller; 260, downward pressure unit; 261, first pressure plate; 262, second pressure plate; 263, third pressure plate; 264, smooth transition structure; 270, air outlet duct; 280, downward pressure of upper extension section; 290, deep volute tongue. Detailed Implementation

[0029] In the description of this application, it should be understood that the terms "center 211a", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between components; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0030] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0031] In this application, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0032] Additionally, if the meaning of "and / or" in the text is that it includes three parallel options, taking "A and / or B" as an example, it includes option A, option B, or an option that satisfies both A and B.

[0033] The present application will now be described in detail through exemplary embodiments. However, it should be understood that, without further description, elements, structures, and features in one embodiment may be advantageously incorporated into other embodiments.

[0034] It should be noted that the total heat exchanger, as an energy-saving ventilation device that combines air replacement and energy recovery, can recover and utilize the sensible and latent heat carried by the indoor air while achieving indoor and outdoor air circulation. This reduces the energy consumption of the air conditioning system and is widely used in various building scenarios such as residences, office buildings, and shopping malls. It ensures the freshness of indoor air and achieves significant energy-saving effects. Its overall structure mainly consists of an outer shell, heat exchange core, fresh air duct, exhaust air duct, fan, and filter components.

[0035] As the power core of a total heat exchanger, the performance of the fan directly determines the equipment's ventilation efficiency, airflow stability, and energy consumption level. Its core function is to drive air to flow in the fresh air or exhaust air duct, achieving effective replacement of indoor and outdoor air. Since total heat exchangers are mostly installed indoors or near living areas, there are clear and stringent requirements for the fan's performance: First, it must ensure stable airflow to guarantee that the ventilation effect consistently meets standards; second, it must meet low noise requirements to avoid disturbing the indoor environment; and third, it must have high static pressure resistance to cope with the resistance from the internal air ducts (such as the core and filter components).

[0036] To improve static pressure resistance, existing wind turbines generally adopt a volute structure design of "upper extension section with lower pressure + deep volute tongue", as shown in the attached figure. Figure 4 As shown. Specifically, the upper extension section of the volute typically slopes downwards at 5-16° to enhance airflow constraint by reducing the outlet area; simultaneously, it is paired with a deep volute tongue 290 design (i.e., the volute tongue extends significantly into the volute), attempting to strengthen anti-static pressure performance through this structure to accommodate the high duct resistance inside the total heat exchanger. However, this design has an unavoidable fatal flaw: firstly, the combination of the downward pressure 280 of the upper extension section and the deep volute tongue 290 directly leads to a reduction in the volute outlet area, resulting in a significant decrease in airflow; to compensate for the airflow loss, the fan speed must be increased, but the increased speed directly causes a surge in aerodynamic noise, creating a sharp conflict with low noise requirements, falling into a vicious cycle of "insufficient airflow - speed increase to compensate - excessive noise." Secondly, strong airflow impact is easily formed between the direct downward extension section and the deep volute tongue 290, and airflow backflow is very likely to occur on both sides of the volute and in the volute tongue area. This will not only further aggravate aerodynamic noise, but also lead to secondary air volume loss, making it difficult for the fan to maintain a stable air volume in a high static pressure environment. At the same time, the extra energy consumption due to airflow turbulence seriously violates the energy-saving requirements. Ultimately, the existing fan cannot take into account static pressure resistance, air volume stability, low noise and energy saving, becoming a key bottleneck restricting the performance improvement of the total heat exchanger.

[0037] Based on this, this application proposes a total heat exchanger. By setting multi-layer stepped down pressure units 260 on the side of the extended plate 221 on the volute facing the fan shaft 211a, the airflow direction is adjusted layer by layer along the steps when the airflow passes through the outlet air duct 270. This achieves the effect of uniform airflow distribution and stable air volume at the volute outlet while ensuring static pressure resistance, and at the same time significantly reducing aerodynamic noise and energy loss. This solves the problem that the existing fan 200 volute structure cannot take into account air volume stability, low noise and energy saving when improving static pressure resistance, resulting in insufficient air volume, excessive noise and increased energy consumption in the total heat exchanger. In the following, embodiments of this application will be described in detail with reference to the accompanying drawings.

[0038] As attached Figures 1-3 As shown in Figures 5-10, in one illustrative embodiment of this application, the total heat exchanger includes a housing 100, on which a fresh air inlet 110, a return air inlet 120, an exhaust air outlet 130, and a supply air outlet 140 are provided. A fresh air duct and an exhaust air duct are provided inside the housing 100. The fresh air inlet 110 is connected to the supply air outlet 140 through the fresh air duct, and the return air inlet 120 is connected to the exhaust air outlet 130 through the exhaust air duct.

[0039] The system includes a fresh air inlet 110 connected to the outside via a duct, used to draw in fresh air from the outside; a supply air outlet 140 connected to the inside via a duct, used to deliver fresh air that has undergone heat exchange and purification into the room to replenish the room with fresh air; a return air outlet 120 connected to the inside via a duct, used to draw air from the room (exhaust air), which is the air that needs to be discharged from the room; and an exhaust outlet 130 connected to the outside via a duct, used to discharge the exhaust air that has completed energy exchange to the outside, which is the final outlet for the indoor polluted air to leave the system.

[0040] In some embodiments, a heat exchange core 150 is also provided inside the housing 100. The heat exchange core 150 is the core where the fresh air duct and the exhaust air duct meet. The heat exchange core 150 is used to realize heat exchange between indoor exhaust air and outdoor fresh air. In addition, it is necessary to ensure that the fresh air duct and the exhaust air duct are isolated from each other to avoid crossflow between fresh air and exhaust air.

[0041] Specifically, the operating principle of the heat exchange core 150 is as follows: outdoor fresh air and indoor exhaust air flow in opposite or vertical cross directions inside the core, and energy exchange is completed in a non-contact manner. In terms of sensible heat exchange, when there is a temperature difference between exhaust air and fresh air, heat will be conducted through the heat exchange plate to achieve temperature regulation between the two. In terms of latent heat exchange, when there is a humidity difference between exhaust air and fresh air, water vapor will diffuse through the moisture-permeable material to achieve humidity regulation between the two. Ultimately, the temperature and humidity of the fresh air are close to the indoor exhaust air state, reducing the energy consumption of the air conditioning system.

[0042] It should be noted that the specific structure of the heat exchange core 150 (including its layered or honeycomb / corrugated structure, overall frame, and connection with the fresh air duct and exhaust duct, etc.) and the operating principle of the heat exchange core 150 (such as energy recovery between fresh air and exhaust air through sensible heat transfer and latent heat transfer, and heat exchange completed by fresh air and exhaust air flowing in opposite or cross directions in the core, etc.) are all prior art, and their technical details are well known to those skilled in the art. Therefore, they need not be described in detail in this application. The main improvement of this application lies in the volute structure of the fan 200, specifically in the upper extension plate 221 and its auxiliary structures. These structures provide progressive airflow guidance to improve airflow conditions and reduce noise. This does not involve any improvement to the existing structure and operating principle of the heat exchange core 150 itself; the same applies below, and will not be described in detail again.

[0043] In some embodiments, a filter assembly is also provided within the housing 100. This filter assembly is a crucial component of the total heat exchanger for air purification. Its core function is to remove impurities such as particulate matter, dust, pollen, and odors from the incoming fresh air, ensuring the cleanliness of the fresh air supplied indoors. It also provides some filtration for the exhaust air, preventing pollutants from entering the environment. Common types of filter assemblies include pre-filters and medium-efficiency filters. Pre-filters typically use materials such as non-woven fabric and metal mesh to filter larger dust and debris particles. Medium-efficiency filters often use materials such as glass fiber and polypropylene to further filter smaller pollutant particles. Some total heat exchangers are also equipped with high-efficiency filters to meet even higher air cleanliness requirements. Within the housing 100, the filter assembly is typically installed at the inlet of the fresh air duct. When outdoor fresh air enters the housing 100, it first flows through the filter assembly and is then filtered before entering the heat exchange core 150 for energy exchange. This effectively prevents impurities in the fresh air from contaminating the heat exchange core 150, ensuring the heat exchange efficiency and service life of the core, while also ensuring that the treated fresh air meets indoor air quality standards.

[0044] It should be noted that the specific structure of the above-mentioned filter components (including the composition of pre-filters, medium-efficiency filters or high-efficiency filters, etc., and their installation positions and connection relationships at the inlet of the fresh air channel and the inlet of the exhaust air channel inside the housing 100) and the operating principle of the filter components (such as removing particulate matter, dust and other impurities in the air through the interception and adsorption of non-woven fabrics, glass fibers and other materials to achieve air purification, etc.) are all existing technologies, and their technical details are well known to those skilled in the art. Therefore, there is no need to elaborate on them in this application.

[0045] In some embodiments, the housing 100 is further provided with two fans 200, which are respectively located in the fresh air duct and the exhaust air duct, and are used to drive the airflow in the fresh air duct and the exhaust air duct respectively.

[0046] In some embodiments, such as Figure 2 and 3 As shown, the fan 200 includes a volute, a base plate 230, a motor 240, and an impeller 250. The volute is fixed to one side of the base plate 230, the motor 240 is fixed to the other side of the base plate 230 away from the volute, and the impeller 250 is placed in the volute chamber formed by the volute and the base plate 230. The drive shaft of the motor 240 is connected to the impeller 250. When working, the motor 240 drives the impeller 250 to rotate, and the rotation of the impeller 250 drives the air, thereby driving the airflow.

[0047] In some embodiments, such as Figure 2 , 3As shown in Figures 5-7, the volute includes a top plate 210 and a surrounding plate 220. The top plate 210 is fixed on the surrounding plate 220. The top plate 210 is provided with a second opening 211, which is an airflow inlet and is connected to the fresh air inlet 110 or the return air inlet 120. The center 211a of the second opening 211 is both the center 211a of the volute and the fan 200 and the axis of the impeller 250.

[0048] In some embodiments, such as Figure 6 , 7 As shown, in a plane perpendicular to the axis of the fan 200, the projection shape of the enclosure 220 in this plane is a spiral or approximately spiral shape, and its outline can be called the outline spiral 223. The enclosure 220 has two ends, one of which is the starting end 223a, which is also the starting end of the airflow, and the other end away from the fan axis 211a is the ending end 223b. The starting end 223a of the enclosure 220 is connected to the volute tongue 222, and the ending end 223b is connected to the upper extension plate 221. The air outlet duct 270 of the volute is between the upper extension plate 221 and the volute tongue 222, and its opening is the air outlet, which is connected to the air supply port 140 or the air exhaust port 130.

[0049] In some embodiments, such as Figure 6 As shown, the upper extension plate 221 is the side wall of the air outlet duct 270. Its plane is parallel to the axis of the fan 200, and it is located on the side of the air outlet duct 270 away from the axis of the fan 200. In addition, the upper extension plate 221 is connected to the surrounding plate 220. The upper extension plate 221 is tangent to the surrounding plate 220 at its connection point, and the upper extension plate 221 extends from its connection point with the surrounding plate 220 in the direction of airflow discharge. Compared with the traditional volute where the upper extension plate 221 is directly pressed down by 5~16°, the upper extension plate 221 in this embodiment is not pressed down, but extends along the tangent of the termination end 223b. This ensures that the airflow can flow according to the designed path when passing through the upper extension plate 221 and the pressing unit, further optimizing the airflow guidance effect, reducing airflow impact and backflow, and thus reducing aerodynamic noise and airflow loss.

[0050] In some embodiments, such as Figure 7 , 8As shown, the volute also includes a pressure unit 260, which is disposed on the side of the upper extension plate 221 facing the fan shaft 211a, and the pressure unit 260 includes a multi-layer stepped structure. When the airflow passes through the air outlet duct 270, it comes into contact with the pressure unit 260, and under the guidance of the pressure unit 260, the airflow direction is deflected layer by layer along its multi-layer stepped structure. The multi-layered stepped downward pressure unit 260 enables the airflow to gradually change direction, avoiding the sudden airflow change problem caused by the direct downward pressure of the traditional upper extension plate 221. This significantly reduces the impact of the airflow on the volute tongue 222, thereby effectively reducing aerodynamic noise. At the same time, it avoids the interaction between the airflow and the deep volute tongue caused by the direct downward pressure on the upper extension section of the volute. This layer-by-layer deflection method allows the airflow to be more evenly distributed at the volute outlet and completely fill the entire outlet airflow. While ensuring static pressure resistance, it reduces airflow attenuation, maintains stable airflow, improves the operating efficiency of the fan 200, and thus optimizes the overall performance of the total heat exchanger. This ensures efficient and stable replacement of indoor and outdoor air, achieves better heat exchange effect, and improves indoor air quality.

[0051] Specifically, the pressing unit 260 includes N pressure plates, all of which are attached to the upper extension plate 221; where N≥3, and N is an integer. Along the direction of airflow discharge, the i-th pressure plate is connected to the (i+1)-th pressure plate; the vertical distance between the windward surface of the i-th pressure plate and the upper extension plate is greater than the vertical distance between the windward surface of the (i+1)-th pressure plate and the upper extension plate; where 1≤i≤N, and i is an integer; When the airflow passes through the outlet duct 270, it comes into contact with the pressure unit 260. Under the guidance of the i-th pressure plate, the airflow deflects and flows along the i-th pressure plate. Then, under the guidance of the (i+1)-th pressure plate, the airflow deflects again and flows along the (i+1)-th pressure plate, and so on. Finally, under the guidance of the N-th pressure plate, the airflow deflects again and flows along the N-th pressure plate. Finally, the airflow is discharged from the outlet duct.

[0052] In some embodiments, the ratio of the projected width of the downpressure unit to the projected width of the upper extension plate on a plane perpendicular to the airflow discharge direction is 0.55 to 0.85. This ensures that the downpressure unit provides sufficient constraint on the airflow, allowing the airflow to smoothly deflect layer by layer along the stepped structure, avoiding insufficient deflection and weakened static pressure resistance caused by a too small proportion of projected width (e.g., <0.55). It also prevents excessive obstruction of the airflow duct caused by a too large proportion (e.g., >0.85), reducing airflow impact and eddy current generation. Thus, while improving static pressure resistance, it reduces aerodynamic noise and airflow loss, balancing the energy efficiency and ventilation efficiency stability of the total heat exchanger. This effectively resolves the contradiction between static pressure resistance and the requirements for low noise and high airflow in traditional direct downpressure structures.

[0053] In some embodiments, the pressure unit 260 includes at least three pressure plates; the thickness of the multiple pressure plates increases sequentially along the airflow discharge direction to form a stepped structure. The multiple pressure plates cooperate with each other, allowing the airflow to change direction more smoothly during layer-by-layer flow, further avoiding severe airflow impact and backflow. The stepped structure formed by the combination of pressure plates of different thicknesses strengthens the layer-by-layer guiding and redirecting effect on the airflow, ensuring static pressure resistance while better maintaining airflow stability, improving the fan's operating performance in high static pressure environments, and ensuring smooth airflow within the total heat exchanger.

[0054] In some embodiments, the thickness difference between any two adjacent pressure plates is 0.5~1 mm. A reasonable thickness difference allows for a smooth transition of airflow between each pressure plate layer, preventing abrupt airflow changes due to excessive thickness variations, and avoiding insufficient airflow guidance due to insufficient thickness variations. This thickness difference range ensures that the airflow maintains a relatively stable velocity and direction as it adjusts its direction layer by layer between multiple pressure plates, continuously reducing aerodynamic noise, optimizing fan performance, and providing stable airflow conditions for the efficient operation of the total heat exchanger.

[0055] In some embodiments, the thickness of the pressure plate ranges from 1 to 11 mm. This thickness range can meet the requirements for airflow constraint and guidance under different operating conditions, ensuring both the structural strength of the pressure plate itself and effectively guiding the airflow. It also indirectly constrains the number of pressure plates.

[0056] In some embodiments, when the thickness difference between two adjacent pressure plates is 0.5mm, a maximum of 21 pressure plates can be set, and the specific arrangement is as follows: along the airflow discharge direction, the thickness of each pressure plate is as follows: 1mm, 1.5mm, 2mm, 2.5mm...10.5mm, 11mm.

[0057] In some embodiments, when the thickness difference between two adjacent pressure plates is 1 mm, a maximum of 11 pressure plates can be set. The specific arrangement is as follows: along the airflow discharge direction, the thickness of each pressure plate is 1 mm, 2 mm, 3 mm, 4 mm...10 mm, 11 mm.

[0058] In some embodiments, the connection between two adjacent pressure plates adopts a rounded corner transition, a beveled corner transition, or an arc-shaped curved surface transition. The smooth transition structure can avoid airflow impact and separation at the pressure plate connection, allowing airflow to pass through each layer of pressure plates continuously and smoothly, further reducing noise generation caused by airflow discontinuity, while reducing energy loss, maintaining airflow stability, ensuring efficient operation of the fan, improving the energy utilization efficiency of the total heat exchanger, and contributing to energy-saving effects.

[0059] Among them, rounded corner transition refers to a smooth arc at the connection between two pressure plates. The radius of the arc can be set as needed. There are no sharp corners at the connection. It naturally curves from the surface of one pressure plate to the other, forming a continuous curved surface, similar to the rounded corner treatment of the edge of a table, using an arc to replace a right angle. Angled corner transition is where the connection between two pressure plates is a plane. This plane forms a certain angle (usually 45°, but can be adjusted to other angles) with the surfaces of the two pressure plates. There is a distinct "slope"-like plane at the connection, connecting the edges of the two pressure plates to form two new included angles, similar to cutting off the right angle of a cube. The cut surface forms an angle with the adjacent two faces, presenting a flat inclined surface. Arc-shaped curved surface transition is more complex than simple rounded corner. It may be composed of multiple arcs of different radii or present a smooth curved surface with non-standard arcs (such as elliptical arcs, parabolic arcs, etc.). The curvature of the surface at the connection may change, making the transition more layered and the shape more flexible, similar to the connecting curved surface between different panels of a car body.

[0060] Preferably, the connection between two adjacent pressure plates is rounded.

[0061] In some embodiments, such as Figure 9 As shown, the pressure unit 260 includes three pressure plates, named first pressure plate 261, second pressure plate 262, and third pressure plate 263. Along the airflow discharge direction, the length-to-length ratio of the three pressure plates is designed to be 1:2:5, which yields the best results in this embodiment. Specifically: First pressure plate 261 (near the fan shaft 211a): the shortest in length, mainly guides the high-speed incoming airflow in the initial stage, causing it to turn smoothly and flow on the surface of the pressure plate; The second pressure plate 262 is twice the length of the first pressure plate 261, further constraining the airflow path, enhancing the control of airflow, and reducing vortex formation; The third pressure plate 263 (near the air outlet duct 270): its length is 5 times that of the first pressure plate 261. Through the longest effective distance, it can fully homogenize the airflow before the outlet, stabilize the flow velocity distribution and reduce the turbulence intensity.

[0062] This stepped length-increasing design, combined with the varying thickness of the multi-layer pressure plates, precisely guides and constrains the airflow in layers. As the airflow passes through the lower pressure unit 260, the direction and velocity are adjusted layer by layer. With the fan axis pointing towards the outlet duct, the shorter pressure plates initially adjust the airflow direction, while the subsequent longer pressure plates not only adjust the airflow direction but also gradually strengthen the control over the airflow. This creates a uniform and stable flow field at the volute outlet, minimizing the impact with the volute tongue 222 and avoiding increased noise due to excessively high local flow velocities. It achieves optimal matching of airflow and noise in a high static pressure environment, optimizes the aerodynamic performance within the total heat exchanger, and improves the overall performance of the equipment.

[0063] In some embodiments, the pressure plate may be made of plastic, resin fiber composite material or metal material such as steel; when the pressure plate and the upper extension plate 221 are made of the same material, they may be integrally formed; in addition, the pressure plate may also be fixed to the upper extension plate 221 by bolts or other mechanical means.

[0064] In some embodiments, such as Figure 10 As shown, the volute also includes at least two wave units 221a, which are all disposed on the side of the upper extension plate 221 facing the fan shaft 211a; along the airflow discharge direction, the wave units 221a are all disposed at the end of the air outlet duct 270.

[0065] Furthermore, all wave units 221a are located on the same straight line, and this straight line is perpendicular to the direction of airflow discharge.

[0066] The wave unit 221a adopts a sinusoidal wave design. After the airflow passes through the pressure unit 260 and is guided layer by layer, it flows further through these wave units 221a towards the outlet duct 270. Although the wave unit 221a will create some resistance at the outlet, the undulating surface of the sinusoidal wave design will have a periodic "pushing" and "guiding" effect on the airflow. At the protruding parts of the wave unit 221a, the airflow is squeezed and flows to the concave areas on both sides, forming a local diversion effect; while the concave parts can accommodate more airflow, and the curved surface guides the airflow that may have been concentrated at the top to diffuse downwards. This periodic diversion and diffusion alternates, gradually breaking the local accumulation state that the airflow may form at the outlet, allowing the airflow that was originally biased to a certain area to be redistributed, and ultimately making the velocity distribution of the upper airflow on the plane more balanced, avoiding airflow turbulence caused by excessively high or low local velocities, thereby achieving the effect of uniform upper airflow distribution. Meanwhile, this structure can reduce the interaction and impact between the outlet airflow and the surrounding structural components, thereby reducing noise. Practical verification has shown that it can achieve a noise reduction of about 0.5 dBA, further optimizing the acoustic performance of the total heat exchanger.

[0067] In some embodiments, the total heat exchanger further includes a control module and a power supply circuit. The power supply circuit provides stable power support to the various electrical components of the total heat exchanger (such as the motor 240 of the fan 200, the control module, etc.) to ensure the normal operation of each component. The control module can receive signals from relevant sensors (such as temperature and humidity sensors, air quality sensors, etc.) and control the start-up, shutdown, and speed of the fan 200 according to a preset program or user instructions to adjust the fresh air volume and exhaust air volume, thereby realizing the intelligent operation of the total heat exchanger and ensuring that the indoor environment is in a suitable state. It should be noted that the specific structure of the control module and power supply circuit (including the composition of the control module, the line connection relationship of the power supply circuit, etc.) and their operating principles (such as the power supply method of the power supply circuit, the signal processing and control logic of the control module, etc.) are all existing technologies, and their technical details are known to those skilled in the art. Therefore, there is no need to elaborate on them in this application.

[0068] For ease of explanation, the above description has been provided in conjunction with specific embodiments. However, the above exemplary discussion is not intended to be exhaustive or to limit the embodiments to the specific forms disclosed above. Various modifications and variations can be obtained based on the above teachings. The selection and description of the above embodiments are for the purpose of better explaining the principles and practical applications, thereby enabling those skilled in the art to better utilize the above embodiments and various different variations of embodiments suitable for specific application considerations.

Claims

1. A total heat exchanger, characterized in that, include: The casing contains a fresh air duct and an exhaust air duct. A heat exchange core is disposed within the housing; It is used to achieve heat exchange between indoor exhaust air and outdoor fresh air; A fan, disposed within the housing, is used to drive airflow in the fresh air duct or the exhaust air duct; wherein the fan includes a volute. The volute includes: Air outlet duct, which is used to exhaust airflow; The upper extension plate is the side wall of the air outlet duct, and its plane is parallel to the axis of the fan. It is located on the side of the air outlet duct away from the axis of the fan. A pressure-reducing unit is disposed on the side of the upper extension plate facing the fan shaft, and the pressure-reducing unit includes a multi-layer stepped structure; The configuration of the pressure unit ensures that when the airflow passes through the air outlet duct, it comes into contact with the pressure unit and, guided by the pressure unit, deflects the airflow direction layer by layer along its multi-layered stepped structure.

2. The total heat exchanger according to claim 1, characterized in that, The volute also includes a surrounding plate, and the upper extension plate is connected to the surrounding plate; the upper extension plate is tangent to the surrounding plate at its connection point with the surrounding plate, and the upper extension plate extends from its connection point with the surrounding plate in the direction of airflow discharge.

3. A total heat exchanger according to claim 1, characterized in that, On a plane perpendicular to the exhaust direction of the airflow, the ratio of the projected width of the pressing unit to the projected width of the upper extension plate on the same plane is 0.55 to 0.

85.

4. A total heat exchanger according to any one of claims 1 to 3, characterized in that, The pressing unit includes at least three pressure plates; along the airflow discharge direction, the thickness of the multiple pressure plates increases sequentially to form a stepped structure.

5. A total heat exchanger according to claim 4, characterized in that, The thickness difference between any two adjacent pressure plates is 0.5~1 mm.

6. A total heat exchanger according to claim 5, characterized in that, The thickness of the pressure plate ranges from 1 to 11 mm.

7. A total heat exchanger according to claim 6, characterized in that, The connection between two adjacent pressure plates adopts a rounded corner transition, a beveled corner transition, or an arc-shaped curved surface transition.

8. A total heat exchanger according to any one of claims 4 to 7, characterized in that, The pressing unit includes three pressure plates; along the airflow discharge direction, the length ratio of the three pressure plates is 1:2:

5.

9. A total heat exchanger according to any one of claims 4 to 7, characterized in that, The volute also includes at least two wave units, each of which is disposed on the side of the upper extension plate facing the fan shaft; along the airflow discharge direction, the wave units are disposed at the end of the air outlet duct.

10. A total heat exchanger, characterized in that, include: The casing contains a fresh air duct and an exhaust air duct. A heat exchange core is disposed within the housing; It is used to achieve heat exchange between indoor exhaust air and outdoor fresh air; A fan, disposed within the housing, is used to drive airflow in the fresh air duct or the exhaust air duct; wherein the fan includes a volute. The volute includes: Air outlet duct, which is used to exhaust airflow; The upper extension plate is the side wall of the air outlet duct, and its plane is parallel to the axis of the fan. It is located on the side of the air outlet duct away from the axis of the fan. A pressure unit is disposed on the side of the upper extension plate facing the fan shaft. The pressure unit includes N pressure plates, all of which are attached to the upper extension plate; wherein, N≥3, and N is an integer. Along the direction of airflow discharge, the i-th pressure plate is connected to the (i+1)-th pressure plate; the vertical distance between the windward surface of the i-th pressure plate and the upper extension plate is greater than the vertical distance between the windward surface of the (i+1)-th pressure plate and the upper extension plate; where 1≤i≤N, and i is an integer; The configuration of the pressure unit ensures that when the airflow passes through the air outlet duct, it comes into contact with the pressure unit and, guided by the pressure unit, the airflow direction is deflected layer by layer along its N pressure plates.

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