Total heat exchange core and fresh air unit

Abstract

This invention discloses a total heat exchange core and a fresh air unit, comprising multiple air inlet channels arranged in one direction and multiple air outlet channels arranged in another direction. The airflow directions of the air inlet channels and the air outlet channels intersect, and a water-permeable membrane separates the air inlet channels and the ventilation volume of the air inlet channels decreases sequentially along the exhaust direction. This invention, by sequentially decreasing the ventilation volume of the air inlet channels along the exhaust direction, increases the ventilation flow of the air inlet channels in contact with the air inlets of the exhaust channels and decreases the ventilation flow of the air inlet channels in contact with the air outlets of the exhaust channels. This results in a larger ventilation flow for channels with high heat exchange capacity, and different flow rates for air inlet channels at different locations, thus matching the flow rate with the heat exchange capacity, improving heat exchange efficiency, and preventing condensation and frost formation at the air outlet side of the exhaust channels when the outdoor temperature is low.

Description

Technical Field

[0001] This invention relates to the field of fresh air technology, and particularly to a total heat exchange core and a fresh air system. Background Technology

[0002] Current fresh air systems utilize a total heat exchange core, enabling heat and humidity exchange between the exhaust air and the air itself, thus recovering the heat and moisture from the exhaust. The square core is a low-resistance, low-cost duct design, with heat and humidity exchange occurring within the core between fresh and exhaust air. Traditional cores primarily improve exchange efficiency by optimizing the structure to increase the heat exchange area.

[0003] For example, patent CN217763885U addresses the low heat exchange efficiency of total heat exchangers by increasing the area of ​​direct contact between the heat exchange membrane and the airflow on both sides, thereby improving the heat exchange efficiency of hot fresh air and exhaust air. However, this approach often overlooks the variability of heat exchange flow within the core, and the accumulation of condensate in the core channels reduces its operational performance. Therefore, under the same material conditions, structural designs that reduce condensate generation and expand the operating temperature range of the core represent a new research direction.

[0004] The total heat exchange core includes multiple air inlet channels arranged in one direction and multiple air outlet channels arranged in another direction, with the air inlet channels and exhaust channels exchanging heat and moisture through cross contact.

[0005] Because of the heat exchange process, the temperatures at the air inlet and outlet of the exhaust duct differ, resulting in varying temperature differences between the inlet and outlet sections. The inlet section closest to the exhaust duct inlet has the largest temperature difference and the highest heat exchange capacity, while the outlet section closest to the exhaust duct has the smallest temperature difference and the lowest heat exchange capacity. However, in conventional cores, the inlet ducts are all the same size, resulting in uniform flow rates for each duct. This mismatch between flow rates and heat exchange capacities leads to inefficient heat and humidity exchange and, when outdoor temperatures are low, condensation and frost formation at the exhaust duct outlet, further hindering ventilation and heat exchange. Summary of the Invention

[0006] To address the mismatch between airflow and heat exchange capacity in air inlet channels at different locations, this invention proposes to give air inlet channels at different locations different flow rates, thereby matching the flow rate with the heat exchange capacity and improving heat exchange efficiency.

[0007] The technical solution adopted in this invention is to design a total heat exchange core, including multiple air inlet channels arranged in one direction and an air outlet channel arranged in another direction. The airflow directions of the air inlet channels and the air outlet channels intersect, and a water-permeable membrane separates the air inlet channels and the air volume of the air inlet channels decreases sequentially along the exhaust direction.

[0008] In some embodiments, the drag coefficient of the air intake passage increases sequentially along the exhaust direction.

[0009] In some embodiments, the drag coefficient of the air intake duct decreases proportionally between 1.4 and 0.7.

[0010] In some embodiments, the air intake channel is provided with a baffle plate that limits the airflow through the air intake channel.

[0011] In some embodiments, the wind deflector is disposed at the air inlet port of the air inlet channel.

[0012] In some embodiments, the wind deflector is a deflector that is inclined inward from the channel wall of the air inlet channel. The greater the inclination angle of the wind deflector relative to the air inlet port of the air inlet channel, the smaller the ventilation volume of the air inlet channel.

[0013] In some embodiments, the wind deflector is integrally formed with the channel wall.

[0014] In some embodiments, the diameter of the air intake passage decreases sequentially along the exhaust direction.

[0015] In some embodiments, the ventilation directions of the air inlet channel and the air outlet channel are arranged in a cross shape.

[0016] Fresh air system, including the aforementioned total heat exchange core.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] In this invention, the ventilation volume of the air inlet channel decreases sequentially along the exhaust direction, thereby increasing the ventilation flow of the air inlet channel in contact with the air inlet of the exhaust channel and decreasing the ventilation flow of the air inlet channel in contact with the air outlet of the exhaust channel. This results in a large ventilation flow for the air inlet channel with high heat exchange capacity, and different flow rates for the air inlet channels at different locations. This ensures that the flow rate matches the heat exchange capacity, improves heat exchange efficiency, and avoids condensation and frost formation on the air outlet side of the exhaust channel when the outdoor temperature is low. Attached Figure Description

[0019] The present invention will now be described in detail with reference to specific embodiments and accompanying drawings. To illustrate the details and facilitate understanding of its principles, the drawings are not necessarily to scale, and similar reference numerals may describe similar components in different views. The accompanying drawings generally illustrate the embodiments discussed herein by way of example and not limitation. Wherein:

[0020] Figure 1 This is a schematic diagram of a fresh air system.

[0021] Figure 2 This is a schematic diagram of a current-technology total heat exchange core.

[0022] Figure 3 This is a schematic diagram of the air intake channel in existing technology.

[0023] Figure 4 This is a schematic diagram of the total heat exchange core of an embodiment.

[0024] Figure 5 This is a schematic diagram of an air inlet channel employing a wind deflector structure, as shown in the embodiment.

[0025] Figure 6 This is a schematic diagram of an embodiment using air inlet channels with different apertures.

[0026] In the diagram, 1 is the fresh air unit; 2 is the total heat exchange core; 201 is the air inlet channel; 202 is the air outlet channel; and 203 is the wind deflector. Detailed Implementation

[0027] The following are specific embodiments of the present invention, and the technical solution of the present invention will be further described in conjunction with the accompanying drawings. However, the present invention is not limited to these embodiments, and the following embodiments do not limit the invention covered by the claims. Furthermore, not all combinations of the features described in the embodiments are necessary for the inventive solution.

[0028] The principles and structure of the present invention will be described in detail below with reference to the accompanying drawings and embodiments.

[0029] Example 1

[0030] A fresh air system is a device that mechanically introduces fresh outdoor air into a room while expelling stale indoor air, thus maintaining fresh and healthy indoor air. Fresh air systems can effectively improve indoor air quality, reduce pollutants and harmful gases, and improve people's respiratory health.

[0031] The working principle of a fresh air system is as follows: it introduces fresh outdoor air into the room after purifying it through a filter, while simultaneously expelling stale indoor air. The system can automatically adjust the air supply and exhaust volumes based on the difference in air quality between indoors and outdoors to maintain fresh and healthy indoor air.

[0032] A total heat exchange fresh air system is a highly efficient indoor air handling device. It combines the functions of a fresh air unit and a heat exchanger, effectively recovering heat and humidity from the indoor air while introducing fresh air, thus achieving efficient energy utilization.

[0033] Total heat exchange fresh air system draws in fresh air from the outside through ventilation ducts, similar to the working method of traditional fresh air system.

[0034] A total heat exchange fresh air system cross-exchanges heat between fresh air and exhaust air before it enters the room. During this process, the fresh air absorbs heat from the outside air and releases heat into the exhaust air. This preheats cold outdoor air in winter, reducing the heating load; and in summer, it transfers heat from the hot outdoor air to the exhaust air, lowering the indoor temperature and reducing the air conditioning load.

[0035] In addition to heat exchange, the total heat exchange fresh air system is also equipped with humidity control. In seasons with high humidity, the system can appropriately reduce the humidity of the outdoor fresh air, thereby improving indoor comfort.

[0036] The main advantage of a total heat exchange fresh air system is its ability to recover heat energy, reduce energy waste, save energy, and lower the operating costs of heating and air conditioning. A total heat exchange fresh air system equipped with heat and humidity exchange functions can also regulate indoor humidity, providing a more comfortable indoor environment.

[0037] The energy-saving and environmentally friendly advantages of total heat exchange fresh air systems have made them an important technology in the field of indoor air treatment. They are widely used in residential, office, and commercial buildings and other places that require air purification and ventilation.

[0038] like Figure 1 As shown, the total heat exchange core 2 used in the fresh air unit 1 can achieve heat and humidity exchange of the exhaust air, thereby realizing the recovery of heat and moisture from the exhaust air. The square core is a low-resistance, low-cost air duct design, where fresh air and exhaust air exchange heat and humidity inside the core. Traditional cores mostly improve exchange efficiency by optimizing the structure to increase the heat exchange area.

[0039] Total heat exchange core dehumidification refers to the process of transferring humidity from the air in addition to heat during the heat exchange process. This technology is commonly used in HVAC systems or other air handling equipment to effectively control air humidity while achieving heat recovery, thereby providing a more comfortable and energy-efficient indoor environment.

[0040] The working principle of a total heat exchange core dehumidification system is to exchange humid air exhausted from indoors with fresh outside air. During the cooler seasons, when the indoor air contains high humidity, this humidity is transferred to the outside air through the heat exchange core, while simultaneously capturing the relatively lower humidity carried by the outside air. In this way, some humidity can be recovered before fresh air enters the room, reducing the dryness of the indoor air and improving indoor comfort.

[0041] Similarly, during the hot season, when the outdoor air is relatively humid, the heat exchange core allows some of the moisture in the air exhausted from the room to be transferred to the outdoor air, thereby reducing the humidity of the indoor air and avoiding the problem of excessive indoor humidity.

[0042] The application of total heat exchange core dehumidification technology can improve the energy efficiency of HVAC systems, save energy consumption, and improve indoor air quality, providing a more comfortable indoor environment. This is of great significance for residential, commercial, and industrial buildings.

[0043] like Figure 2 As shown, the total heat exchange core includes multiple air inlet channels arranged in one direction and multiple air outlet channels arranged in another direction, with the air inlet channels and air outlet channels exchanging heat and moisture through cross contact.

[0044] Because of heat exchange, the temperature at the air inlet and outlet of the exhaust duct is different. Therefore, the temperature difference between the air inlet and exhaust duct varies at different locations. The air inlet in contact with the air outlet of the exhaust duct has the largest temperature difference and the highest heat exchange capacity. The air inlet in contact with the air outlet of the exhaust duct has the smallest temperature difference and the smallest heat exchange capacity.

[0045] like Figure 3 As shown, the air inlet channels of a conventional core are all the same size, so the flow rate in each channel is the same. This leads to a mismatch between the flow rate and heat exchange capacity of the air inlet channels at different locations. Not only is efficient heat and humidity exchange ineffective, but when the outdoor temperature is low, condensation and frost easily form at the exhaust outlet of the exhaust channel, further affecting ventilation and heat exchange. In winter, when the outdoor temperature is -15 degrees Celsius and the indoor temperature is 20 degrees Celsius, the exhaust air temperature at the exhaust outlet of the exhaust channel is close to -10 degrees Celsius, making it most prone to condensation and frost. Therefore, cores with uniform flow channels are more prone to condensation and frost at the exhaust outlet of the core.

[0046] Condensation and frosting in a total heat exchanger core refers to the phenomenon where water vapor in the air condenses and frosts on the core surface during heat exchange due to factors such as temperature differences and relative humidity. When water vapor in warm air comes into contact with the cooler surface of the total heat exchanger core, it condenses into liquid water due to the temperature drop; this phenomenon is called condensation. Condensation can cause the core surface to become wet, which is why some total heat exchangers are equipped with condensation drainage devices.

[0047] When water vapor in the air condenses on the core surface, if the temperature continues to drop, this condensed water will further cool and turn into ice, forming frost. Frost causes the core surface to become rougher, affecting heat exchange efficiency and potentially causing blockage of the total heat exchanger.

[0048] Therefore, such as Figure 4 , 5As shown, a total heat exchange core for use in a fresh air system is provided. The total heat exchange core mainly comprises two adjacent layers of channels separated by a permeable membrane to facilitate moisture exchange. One layer is an air inlet channel 201, and the other is an exhaust channel 202. Multiple air inlet channels 201 are arranged in one direction, and multiple exhaust channels 202 are arranged in another direction. The air inlet channels 201 and exhaust channels 202 are intersected, causing their airflow directions to intersect. This cross-shaped ventilation arrangement of the air inlet channels 201 and exhaust channels 202 results in a simple structure suitable for use with square heat exchange cores.

[0049] Total heat exchange core membranes are special membrane materials used in heat exchangers to achieve heat and humidity transfer. These membrane materials are typically highly selective, allowing specific substances (such as water vapor) to pass through while blocking the transfer of other substances.

[0050] The permeable membrane separating the two channels is an exchange membrane, whose main function in the total heat exchange core is to achieve humidity recovery. When heat is transferred between two gases or between a gas and a liquid, the exchange membrane allows one gas (usually water vapor) to pass through while blocking the transfer of the other gas. In this way, humidity is transferred simultaneously with heat transfer between the two fluids, thereby regulating the humidity of the indoor air to a certain extent.

[0051] In HVAC systems, total heat exchange core membranes can be used to recover water vapor from humid air exhausted from indoors and transfer it to fresh outside air entering the room, thereby improving indoor air humidity. This avoids the problem of excessively dry indoor air in the cold season or excessively humid indoor air in the hot season. The performance and selection of total heat exchange core membranes depend on specific application requirements and operating conditions. High-efficiency exchange membranes can achieve better humidity recovery, thereby improving energy efficiency, reducing operating costs, and providing a more comfortable and energy-efficient indoor environment for air conditioning and air handling systems.

[0052] The ventilation volume of the air intake channels decreases sequentially along the exhaust direction, meaning that the ventilation flow rate of the air intake channels in contact with the exhaust channel inlets increases, while the ventilation flow rate of the air intake channels in contact with the exhaust channel outlets decreases. This results in a larger ventilation flow rate for channels with high heat exchange capacity, and different flow rates for air intake channels at different locations, thus matching the flow rate with the heat exchange capacity, improving heat exchange efficiency, and preventing condensation and frosting from easily forming on the exhaust channel outlet side when the outdoor temperature is low.

[0053] For ease of explanation, the air inlet channels arranged from the air inlet to the air outlet are channel 1, channel 2, channel 3, ..., channel N; and the air outlet channels arranged from the air inlet to the air outlet are channel a, channel b, channel c, ..., channel x.

[0054] This can be achieved by setting resistance in the air intake channels, for example, by increasing the resistance coefficient of the air intake channels sequentially along the exhaust direction, thereby resulting in different flow rates in different air intake channels. This configuration is simple. Assume that the resistance coefficients of each channel are Z1, Z2...ZN, such that ZN > ... Z2 > Z1.

[0055] Let the average airflow of a single channel be A, then A\Z1 + A\Z2… = the total design airflow Q. When ZN = 1.4 and Z1 = 0.7, the resistance coefficients of other channels decrease proportionally between 1.4 and 0.7. The core humidity exchange effect of this invention is the best.

[0056] If the airflow of channel 1 is A / ZN = A / 0.7, and channels a, b, c, ..., x have uniform airflow, when the rated airflow of both fresh air and exhaust air is Q, the humidity exchange capacity of channels 1 and the exhaust air channel increases by approximately 40% compared to the original. Similarly, the humidity of the exhaust air in channels 1, 2, 3, ..., N decreases sequentially. The reduced humidity in the exhaust air significantly improves condensation at the core outlet. Furthermore, the core's stepped humidity recovery primarily focuses on humidity recovery at locations with higher core temperatures, thus increasing the moisture exchange capacity.

[0057] The air inlet channel is equipped with a baffle plate 203 that limits the airflow. The amount of air entering the air inlet channel is controlled by the baffle plate 203. This design is simple to manufacture, low in cost, and easy to control. The baffle plate 203 is located at the air inlet port of the air inlet channel, thus limiting the incoming airflow and facilitating flow control.

[0058] The wind deflector 203 is a deflector that is inclined inward from the channel wall of the air inlet channel. The greater the inclination angle of the wind deflector 203 relative to the air inlet port of the air inlet channel, the smaller the ventilation volume of the air inlet channel. The ventilation volume can be controlled by simply adjusting the angle of the deflector. It is simple to operate and convenient to use.

[0059] The wind deflector is integrally formed with the channel wall, which facilitates production and reduces costs.

[0060] like Figure 6 As shown, the flow rate of each channel can be controlled by successively decreasing the aperture of the air inlet channel along the exhaust direction, thus eliminating the need for a baffle structure.

[0061] The airflow in the total heat exchange core is controlled by baffles. The total heat exchange core typically has inlet and outlet air channels for exchanging heat and humidity. By adjusting the opening of the baffles, the airflow into the total heat exchange core can be controlled, thereby regulating the heat exchange efficiency and humidity recovery effect.

[0062] The baffle plate in the total heat exchange core is typically located at the entrance of the air intake channel. By adjusting the opening of the baffle plate, the cross-sectional area of ​​the air intake channel can be changed, thereby controlling the airflow. When the baffle plate is fully open, the airflow is at its maximum; when the baffle plate is fully closed, air cannot enter the total heat exchange core.

[0063] By adjusting the opening of the baffle, the air intake of the total heat exchange core can be controlled according to actual needs. This is particularly useful in HVAC systems, as it allows the operating status of the total heat exchange core to be adjusted according to indoor temperature and humidity requirements, providing a more comfortable and energy-efficient indoor environment.

[0064] It is also worth noting that the adjustment of the baffles needs to be designed and operated rationally based on the specific application and the performance of the heat exchange core. Improper adjustment may affect the heat exchange efficiency of the total heat exchange core and even lead to equipment failure. Therefore, in practical applications, it is necessary to ensure the proper operation and control of the baffles according to system requirements and design specifications to achieve the expected results.

[0065] Although this document uses a number of technical terms, the possibility of using other terms is not excluded. These terms are used merely for the convenience of describing and explaining the essence of the invention; interpreting them as any additional limitation would contradict the spirit of the invention. The order of actions, steps, etc., in the apparatus and methods shown in the specification and drawings can be implemented in any order unless otherwise expressly specified, and provided that the output of a preceding process is not used in a subsequent process. Similar sequential terms used for descriptive convenience (e.g., "firstly," "next," "secondly," "again," "then," etc.) do not imply that the actions must be performed in such an order.

[0066] Those skilled in the art will understand that all directional references (e.g., above, below, up, up, down, down, top, bottom, left, right, vertical, horizontal, etc.) are used descriptively in the drawings to aid the reader's understanding and do not imply (e.g., a limitation on the scope of the invention as defined by the appended claims) a limitation on the scope of the invention as defined by the appended claims. They are merely for the purpose of facilitating the description of this application and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a particular orientation or be constructed and operated in a particular orientation. The directional terms "inside" and "outside" refer to inside or outside relative to the outline of the respective component itself.

[0067] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0068] Additionally, some vague terms (e.g., substantially, certain, generally, etc.) may refer to slight inaccuracies or minor deviations in conditions, quantities, values, or dimensions, some of which are within manufacturing tolerances or limits. It should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components; unless otherwise stated, these terms have no special meaning and therefore should not be construed as limiting the scope of protection of this application.

[0069] The specific embodiments described herein are merely illustrative examples illustrating the spirit of the invention. Those skilled in the art can make various modifications or additions to the described embodiments or use similar methods to substitute them, without departing from the spirit of the invention or exceeding the scope defined by the appended claims.

Claims

1. A total heat exchange core comprising a plurality of air inlet channels arranged in one direction and air outlet channels arranged in another direction, said air inlet channels being arranged crosswise to the air flow direction of said air outlet channels, said air inlet channels and said air outlet channels being separated by a water permeable membrane, characterized in that, The ventilation volume of the air intake channel decreases sequentially along the exhaust direction.

2. The total heat exchange core of claim 1, wherein, The resistance coefficient of the air intake channel increases sequentially along the exhaust direction.

3. The total heat exchange core of claim 2, wherein, The resistance coefficient of the air intake channel decreases proportionally between 1.4 and 0.

7.

4. The total heat exchange core according to claim 1, characterized in that, The air intake channel is equipped with a baffle plate that limits the airflow of the air intake channel.

5. The total heat exchange core according to claim 4, characterized in that, The wind deflector is located at the air inlet port of the air inlet channel.

6. The total heat exchange core according to claim 5, characterized in that, The wind deflector is a deflector that is inclined inward from the channel wall of the air inlet channel. The greater the inclination angle of the wind deflector relative to the air inlet port of the air inlet channel, the smaller the ventilation volume of the air inlet channel.

7. The total heat exchange core according to claim 6, characterized in that, The wind deflector is integrally formed with the channel wall.

8. The total heat exchange core according to claim 1, characterized in that, The cross-section of the air intake channel decreases sequentially along the exhaust direction.

9. The total heat exchange core according to claim 1, characterized in that, The ventilation directions of the air inlet channel and the air outlet channel are arranged in a cross shape.

10. A fresh air purifier, characterized in that, Includes the total heat exchange core as described in any one of claims 1 to 9.

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