A PTFE-graphene composite membrane heat exchanger
By using a honeycomb flow channel core with a graphene-PTFE composite membrane structure in livestock sheds, the problem of low efficiency of traditional heat exchangers under extremely cold conditions has been solved, achieving efficient heat recovery and gas treatment, ensuring a stable environment inside the sheds, and improving breeding efficiency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- BEIJING NENGSHANG TECHNOLOGY CO LTD
- Filing Date
- 2025-06-27
- Publication Date
- 2026-05-26
AI Technical Summary
In livestock sheds in cold regions, traditional heat exchangers are inefficient, leading to excessive ammonia levels, temperature imbalances, and an inability to effectively control the breeding environment. In particular, under extremely cold conditions, heat recovery is insufficient, failing to meet the needs of healthy growth and efficient breeding.
The honeycomb flow channel core, which adopts a graphene-PTFE composite membrane structure, is designed with a 15° tilt angle and combined with a SiO2 nano-hydrophobic layer to form a hexagonal cross-section, enhances turbulence control, improves heat exchange efficiency and gas handling capacity, and avoids water accumulation and frost formation.
The sensible heat efficiency is increased to 89%, the critical temperature for frosting is reduced to -25℃, and the pressure drop is reduced by 29%, ensuring stable and efficient operation of the system in extremely cold environments and improving the temperature control capability of the aquaculture environment.
Smart Images
Figure CN224285602U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of heat exchanger technology, specifically to a PTFE-graphene composite membrane heat exchanger. Background Technology
[0002] In the livestock farming industry, controlling the breeding environment is crucial for the healthy growth of livestock and the profitability of farming. Especially in cold regions, to maintain the temperature inside the sheds during winter, closed management is typically used. For example, in cold regions like Inner Mongolia, where outdoor temperatures often drop below -22℃ in winter, traditional closed management of sheep sheds presents the following problems: Excessive ammonia: In a closed environment, the NH3 concentration often exceeds 20ppm (the national standard limit is ≤10ppm), leading to frequent respiratory diseases in sheep and a decline in meat quality; Temperature imbalance: Traditional ventilation requires opening windows for air exchange, causing a sudden drop in temperature inside the shed (e.g., from 5℃ to -10℃), resulting in frostbite or even death in livestock.
[0003] Existing environmental control systems suffer from insufficient heat recovery, and conventional aluminum foil heat exchangers are inefficient (sensible heat recovery ≤68%), making them unsuitable for extremely cold conditions. Utility Model Content
[0004] In view of the shortcomings of the existing technology, the purpose of this utility model is to provide a PTFE-graphene composite membrane heat exchanger.
[0005] To achieve the above objectives, this utility model provides the following technical solution:
[0006] A PTFE-graphene composite membrane heat exchanger includes a heat recovery core, the heat recovery core comprising several honeycomb flow channel cores spliced together, each of the honeycomb flow channel cores employing a graphene-PTFE composite membrane structure, and the honeycomb flow channel cores being configured with an airflow tilt angle of 15° relative to the primary air inlet.
[0007] In this invention, preferably, the graphene-PTFE composite membrane structure comprises, from the inside out, a graphene inner coating layer, a PTFE microporous base membrane layer, and a SiO2 nanohydrophobic layer fixed together.
[0008] In this invention, preferably, the cross-section of the honeycomb flow channel core is hexagonal.
[0009] In this utility model, preferably, the composite heat exchanger further includes an outer frame, on which a primary air inlet, a fresh air inlet, a secondary air inlet, and an exhaust outlet are provided on both sides.
[0010] In this utility model, preferably, the primary air inlet and the exhaust outlet pass sequentially through the exhaust filter, the heat recovery core, and the exhaust fan along the direction of air flow.
[0011] In this invention, preferably, the secondary air inlet and the fresh air inlet are connected sequentially along the direction of airflow by an air supply filter and a heat recovery core.
[0012] In this invention, preferably, the thickness of the graphene inner coating is 200 nm.
[0013] In this invention, preferably, the thickness of the PTFE microporous base film layer is 50 μm.
[0014] In this invention, preferably, the thickness of the SiO2 nanohydrophobic layer is 5 μm.
[0015] In this invention, preferably, the hexagonal honeycomb flow channel core has a single-side width of 2mm and a depth of 10mm.
[0016] Compared with the prior art, the beneficial effects of this utility model are:
[0017] The hexagonal honeycomb flow channel core and 15° tilt of the graphene-PTFE composite membrane structure of this invention improve heat exchange efficiency and gas handling capacity. The turbulence control strategy further enhances the system performance, improves sensible heat efficiency, avoids water accumulation and frost formation, and makes the system more stable and efficient. Attached Figure Description
[0018] Figure 1 This is a schematic diagram of the PTFE-graphene composite membrane heat exchanger described in this utility model.
[0019] Figure 2 This is a three-dimensional structural diagram of the heat recovery mechanism described in this utility model.
[0020] Figure 3 This is a front structural diagram of the heat recovery mechanism described in this utility model.
[0021] Figure 4 This is a schematic diagram of the graphene-PTFE composite membrane structure described in this utility model. Detailed Implementation
[0022] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.
[0023] It should be noted that when a component is described as "fixed to" another component, it can be directly on the other component or may have a component in between. When a component is considered "connected to" another component, it can be directly connected to the other component or may have a component in between. When a component is considered "set on" another component, it can be directly set on the other component or may have a component in between. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.
[0024] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.
[0025] Please also see Figures 1-3 A preferred embodiment of this utility model provides a PTFE-graphene composite membrane heat exchanger, including a heat recovery core 1. The heat recovery core 1 includes several honeycomb flow channel cores 2 spliced together. Each honeycomb flow channel core 2 adopts a graphene-PTFE composite membrane structure 3. The honeycomb flow channel core 2 is set with an airflow tilt angle of 15° relative to the primary air inlet 5.
[0026] like Figure 4 As shown, in this embodiment, the graphene-PTFE composite membrane structure 3 includes, from the inside out, a graphene inner coating layer 31, a PTFE microporous base membrane layer 32, and a SiO2 nanohydrophobic layer 33 fixed together.
[0027] In this embodiment, the graphene inner coating 31 has a thickness of 200 nm, the PTFE microporous base film layer 32 has a thickness of 50 μm, and the SiO2 nano-hydrophobic layer 33 has a thickness of 5 μm. The use of the graphene inner coating 31 improves thermal conductivity, and the PTFE microporous base film layer 32 has a porosity of 85% and an air permeability ≥8 L / (m³). 2 The outer SiO2 nano-hydrophobic layer 33 prevents frost formation and resists contamination. This increases the sensible heat efficiency of the heat recovery core 1 to 89% and lowers the critical frost temperature to -25℃ (compared to -5℃ in conventional systems), making it suitable for extremely cold environments.
[0028] When the core wall of the honeycomb flow channel is designed with a 15° inclination, the fluid (such as fresh air and exhaust air) is forced to change its flow direction as it flows through the honeycomb structure, generating secondary flows (such as vortices and lateral flows). This change in flow state significantly increases the turbulence intensity of the fluid (increases the Reynolds number Re), breaking the originally stable laminar thermal boundary layer. The thermal boundary layer is a low-velocity region formed between the fluid and the wall due to viscosity, hindering heat transfer. Turbulence effectively reduces the thickness of the thermal boundary layer by enhancing fluid disturbance, thereby improving heat conduction efficiency. The 15° inclination angle extends the effective flow path of the fluid within the flow channel. The countercurrent contact time between fresh air and exhaust air increases by 30%, allowing for sufficient heat exchange. The 15° inclination angle is close to the optimal fluid dynamics angle (critical angle approximately 12-18 degrees), effectively suppressing flow separation and reducing energy loss. Pressure drop reduction: Compared to a vertical flow channel (pressure drop of 120 Pa), the pressure drop of the 15° inclination channel is reduced to 85 Pa, a reduction of approximately 29%. Low pressure drop allows for higher airflow without increasing energy consumption, indirectly improving sensible heat efficiency. The inclined honeycomb flow channel core 2, combined with a graphene-PTFE composite film (thermal conductivity 120W / m·K), further enhances heat transfer from the exhaust side to the fresh air side. Simultaneously, the 15° inclination angle facilitates rapid drainage of condensate along the wall surface, preventing water accumulation and frost formation. Combined with a SiO2 nano-hydrophobic layer 33 (contact angle > 150°), the critical frosting temperature is reduced from -5°C to -25°C, ensuring continuous high-efficiency operation in extremely cold environments.
[0029] In this embodiment, the cross-section of the honeycomb flow channel core 2 is hexagonal.
[0030] In this embodiment, the composite heat exchanger also includes an outer frame 4, on which a primary air inlet 5, a fresh air inlet 6, a secondary air inlet 7, and an exhaust outlet 8 are provided on both sides.
[0031] In this embodiment, the primary air inlet 5 and the exhaust outlet 8 pass sequentially through the exhaust filter 9, the heat recovery core 1, and the exhaust fan 10 along the direction of air flow.
[0032] In this embodiment, the secondary air inlet 7 and the fresh air inlet 6 pass sequentially through the air supply filter 11 and the heat recovery core 1 along the airflow direction.
[0033] In this embodiment, the hexagonal honeycomb flow channel core 2 has a single-side width of 2mm and a depth of 10mm. It is connected in an interlaced manner with an inclination angle of 15° and a spacing of 10mm. By having fresh and exhaust air flow counter-currently through the honeycomb flow channel core 2, local turbulence (Reynolds number Re > 4000) is generated in the airflow; the turbulence breaks down the boundary layer, increasing the heat transfer coefficient to 85W / (m³). 2 ·K)(Traditional laminar flow is only 35W / (m 2With a heat transfer efficiency of 89% (compared to only 68% for traditional aluminum foil channels), the sensible heat transfer efficiency reaches 89%.
[0034] The above description is a detailed description of the preferred embodiments of the present utility model. However, the embodiments are not intended to limit the scope of the patent application of the present utility model. All equivalent changes or modifications made under the technical spirit of the present utility model should fall within the patent scope covered by the present utility model.
Claims
1. A PTFE-graphene composite membrane heat exchanger, characterized in that, It includes a heat recovery core (1), which includes several honeycomb flow channel cores (2) spliced together. Each of the honeycomb flow channel cores (2) adopts a graphene-PTFE composite film structure (3), and the honeycomb flow channel cores (2) are set with an airflow tilt angle of 15° relative to the primary air inlet (5).
2. The PTFE-graphene composite membrane heat exchanger according to claim 1, characterized in that, The graphene-PTFE composite membrane structure (3) comprises, from the inside out, a graphene inner coating layer (31), a PTFE microporous base membrane layer (32), and a SiO2 nanohydrophobic layer (33) fixed together.
3. A PTFE-graphene composite membrane heat exchanger according to claim 2, characterized in that, The cross-section of the honeycomb flow channel core (2) is hexagonal.
4. A PTFE-graphene composite membrane heat exchanger according to claim 2, characterized in that, It also includes an outer frame (4), on both sides of which are provided a primary air inlet (5), a fresh air inlet (6), a secondary air inlet (7), and an exhaust outlet (8).
5. A PTFE-graphene composite membrane heat exchanger according to claim 1, characterized in that, The primary air inlet (5) and the exhaust outlet (8) pass sequentially through the exhaust filter (9), the heat recovery core (1), and the exhaust fan (10) along the direction of air flow.
6. A PTFE-graphene composite membrane heat exchanger according to claim 4, characterized in that, The secondary air inlet (7) and the fresh air inlet (6) pass sequentially through the air supply filter (11) and the heat recovery core (1) along the direction of air flow.
7. A PTFE-graphene composite membrane heat exchanger according to claim 2, characterized in that, The thickness of the graphene inner coating (31) is 200 nm.
8. A PTFE-graphene composite membrane heat exchanger according to claim 2, characterized in that, The thickness of the PTFE microporous base film (32) is 50 μm.
9. A PTFE-graphene composite membrane heat exchanger according to claim 2, characterized in that, The thickness of the SiO2 nanohydrophobic layer (33) is 5 μm.
10. A PTFE-graphene composite membrane heat exchanger according to claim 3, characterized in that, The hexagonal honeycomb flow channel core (2) has a single-side width of 2 mm and a depth of 10 mm.