Fresh air waste heat recovery device based on plate-fin pulsating heat pipe

Abstract

The invention discloses a fresh air waste heat recovery device based on a plate-fin pulsating heat pipe. The fresh air waste heat recovery device comprises a case, an air duct, a moisture-permeable air blocking film, a fresh air filter, a fresh air fan, an exhaust fan and a pulsating heat pipe heat exchanger. The air channel is divided into a fresh air channel and an exhaust air channel through a moisture-permeable air-blocking film, fresh air is prevented from making direct contact with exhaust air, and meanwhile latent heat in the exhaust air is recycled. The plate-fin pulsating heat pipe heat exchanger is installed in the middle of the air duct, a capillary structure of the plate-fin pulsating heat pipe heat exchanger is filled with a liquid working medium, the working medium is driven by temperature difference to generate phase change self-oscillation flow in a pipe, and efficient heat transfer is achieved. According to the heat exchanger, turbulent flow is enhanced through the dense fins and secondary structures on the surfaces of the fins, the heat exchange efficiency of air and the fins is improved, and heat is more effectively transmitted into the pulsating heat pipe. During operation in winter, the device can recover heat in exhaust air to preheat fresh air; and during operation in summer, the fresh air temperature can be reduced, and the pre-cooling effect is achieved.

Description

Technical Field

[0001] The present invention relates to the field of heating, ventilation and air conditioning, and more particularly to a heat recovery device for a fresh air system. More specifically, the present invention relates to a fresh air waste heat recovery device based on pulsating heat pipe technology, which is used to improve the energy efficiency of the fresh air system, especially for application in the heat recovery system of buildings. Background Art

[0002] With the improvement of building energy conservation and indoor air quality requirements, fresh air ventilation systems are widely used in modern buildings. However, in the traditional fresh air ventilation process, the indoor exhaust air is usually directly discharged outdoors, resulting in a large amount of heat energy loss. Especially in winter and summer, this energy waste will significantly increase the heating or cooling load of the building and reduce the overall energy utilization efficiency. Therefore, waste heat recovery technology has become the key means to improve the energy efficiency of the fresh air system.

[0003] Currently, the common fresh air waste heat recovery devices on the market mainly adopt technologies such as plate heat exchangers and rotary heat exchangers. However, traditional plate heat exchangers have problems such as large air flow resistance and easy condensation and frosting; due to the presence of rotating components, rotary heat exchangers are prone to leakage risks and have high maintenance costs. These traditional devices often have problems such as low heat exchange efficiency, complex structure, and large space occupation. Summary of the Invention

[0004] The purpose of the present invention is to overcome the deficiencies of existing fresh air waste heat recovery devices in heat exchange efficiency, air flow resistance, frosting and condensation, etc., and provide a fresh air waste heat recovery device based on pulsating heat pipes. Through the synergistic effect of the pulsating heat pipe heat exchanger and the moisture-permeable and air-blocking film, this device can efficiently recover the sensible heat and latent heat in the exhaust air, improve the fresh air heat exchange efficiency, reduce the heating or cooling load of the building, and at the same time optimize the indoor air quality.

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

[0006] A fresh air waste heat recovery device based on pulsating heat pipes, the device includes:

[0007] A chassis;

[0008] The chassis is divided into a parallel fresh air duct and an exhaust air duct by a duct partition; the duct partition includes a moisture-permeable and air-blocking film;

[0009] A pulsating heat pipe heat exchanger provided in the chassis, and the pulsating heat pipe heat exchanger is connected to the fresh air duct and the exhaust air duct.

[0010] Further, a fresh air filter is installed at the inlet of the fresh air duct; it includes a louver filter mesh cover and a polymer filter pad.

[0011] Further, an exhaust air fan is provided at the inlet of the exhaust air duct.

[0012] Furthermore, the moisture-permeable and air-barrier film is fixed between the fresh air duct and the exhaust air duct by means of a clamping groove assembly.

[0013] Furthermore, check valves are provided at the outlets of both the fresh air duct and the exhaust air duct.

[0014] Furthermore, the pulsating heat pipe heat exchanger is composed of several pulsating heat pipes welded side by side, forms a loop through multiple bends, and has a filling port.

[0015] Furthermore, a pulsating heat pipe clamping assembly is arranged between two groups of moisture-permeable and air-barrier films for connecting the pulsating heat pipe heat exchanger and the moisture-permeable and air-barrier films.

[0016] Furthermore, heat exchange fins are arranged between the pulsating heat pipes.

[0017] Furthermore, a secondary structure is provided on the surface of the heat exchange fins.

[0018] Furthermore, the device is equipped with a temperature and humidity sensor and an air flow regulating device. The temperature and humidity sensor is used for linkage detection of indoor and outdoor temperature and humidity, and the air flow regulating device adjusts the fresh air and exhaust air flows according to the indoor and outdoor temperature and humidity.

[0019] Compared with the prior art, the significant advantages of the present invention are as follows:

[0020] 1. High-efficiency waste heat recovery: By adopting the pulsating heat pipe technology, the sensible heat exchange efficiency is improved. At the same time, combined with the moisture-permeable and air-barrier film, the latent heat is effectively recovered and the heat loss is reduced.

[0021] 2. Low air flow resistance and reduced energy consumption: The plate fin structure optimizes the air flow distribution. Compared with the traditional plate heat exchanger, the air flow resistance is reduced and the fan energy consumption is lowered.

[0022] 3. Anti-frost design and adaptation to low-temperature environment: The moisture-permeable and air-barrier film avoids direct condensation, improves the stability under low-temperature conditions, and is applicable to cold climate conditions.

[0023] 4. Intelligent air volume regulation and optimization of indoor environment: Through the air flow regulating device and combined with the temperature and humidity sensor, the fresh air and exhaust air volumes can be intelligently adjusted according to environmental changes, ensuring indoor air quality and improving energy efficiency.

[0024] 5. Modular design, easy installation and maintenance: Adopting a modular component design, the equipment is convenient to install and has low maintenance costs, and is applicable to the renovation or new construction projects of fresh air systems for different building types. Description of the Drawings

[0025] To more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0026] Figure 1 Schematic diagram of the internal structure of the housing of the present invention.

[0027] Figure 2 Schematic diagram of the moisture-permeable and air-barrier film card slot assembly and the pulsating heat pipe buckle assembly.

[0028] Figure 3 Schematic diagram of the filter and the fan.

[0029] Figure 4 Schematic diagram of the plate-fin type pulsating heat pipe.

[0030] Figure 5 Schematic diagram of the secondary structure on the fin surface.

[0031] In the figure: 1, chassis housing; 2, fresh air duct; 3, exhaust air duct; 4, filter and fresh air fan; 5, exhaust air fan; 6, air duct partition; 7, plate-fin type pulsating heat pipe heat exchanger; 8, air hood; 9, check valve; 41, louvered mesh cover; 42, polymer filter pad; 43, fresh air fan; 61, card slot assembly 1; 62, moisture-permeable and air-barrier film; 63, 64, pulsating heat pipe buckle assembly; 71, pulsating heat pipe; 72, heat transfer fins; 73, pulsating heat pipe filling port. Detailed implementation manners

[0032] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0033] As Figure 1 shown, the present invention provides a fresh air waste heat recovery device based on a pulsating heat pipe, and its main structure includes: chassis 1, fresh air duct 2, exhaust air duct 3, filter and fresh air fan 4, exhaust air fan 5, air duct partition 6, plate-fin type pulsating heat pipe heat exchanger 7, air hood 8 and check valve 9.

[0034] The fresh air duct 2 and the exhaust air duct 3 are arranged inside the chassis 1, and the cross-sectional size of the air duct can be customized according to building requirements (such as 250 mm × 200 mm). The fresh air duct 2 and the exhaust air duct 3 are separated by the air duct partition 6 to respectively guide the flow of outdoor fresh air and indoor exhaust air.Figure 1 In the figure, the air duct on the upper part of the air duct partition 6 is the fresh air duct 2, one end of which is provided with a fresh air fan 4, which draws air from the outside and sends it into the fresh air duct 2; the other end of the fresh air duct 2 is provided with a hood 8. The lower part of the air duct partition 6 is the exhaust air duct 3, one end of which is provided with an exhaust fan 5, which draws air from the room and sends it into the exhaust air duct 3, and the other end of the exhaust air duct 3 is provided with a hood 8.

[0035] The air duct partition 6 includes a moisture-permeable gas-blocking film 62 and a slot assembly. The moisture-permeable gas-blocking film 62 is fixed between the fresh air duct 2 and the exhaust air duct 3 by the slot assembly; it can block the direct contact between the fresh air and the exhaust air, while allowing water vapor to pass through to achieve latent heat recovery. Its specific structure is as follows Figure 2 As shown, the two ends of the moisture permeable gas barrier film 62 are set to a T-shaped protrusion structure; the two sides thereof are matched with a slot assembly 61, and the slot assembly has a T-shaped slot for clamping the moisture permeable gas barrier film 62. Between the two groups of moisture permeable gas barrier films 62, a pulsating heat pipe buckle assembly 63, 64 is set to connect the pulsating heat pipe heat exchanger 7 with the moisture permeable gas barrier film 62.

[0036] The moisture-permeable and air-blocking membrane 62 is made of highly breathable and antibacterial materials to ensure water vapor permeation while blocking bacteria and harmful substances in the air. The moisture-permeable and air-blocking membrane 62 is designed to balance the humidity of exhaust air and fresh air, recovering part of the latent heat, that is, dehumidifying the fresh air in summer and humidifying the fresh air in winter.

[0037] The fresh air filter 4 is installed at the entrance of the fresh air duct 2. Figure 3 As shown, it adopts a shutter filter cover 41 and a polymer filter pad 42 to remove particulate matter and pollutants in the air and ensure clean air in the air duct.

[0038] Check valve 9 is installed at the fresh air and exhaust air outlets to prevent wind backflow and mosquitoes from entering.

[0039] The pulsating heat pipe heat exchanger 7 is installed in the center of the fresh air duct 2 and the exhaust air duct 3. Its length direction is consistent with the width direction of the duct, and its external dimensions are adapted to the cross-sectional dimensions of the duct. A 3% installation gap is reserved in the horizontal and vertical dimensions to ensure that the heat exchanger can be stably embedded and installed, and to leave enough channels for airflow to avoid significantly increasing wind resistance. Figure 4 As shown in FIG. 1 , the heat exchanger is composed of a "harmonica-style" pulsating heat pipe 71, which contains dozens of parallel channels inside and forms a loop through multiple bends. Finally, a proper amount of working fluid is filled through a special filling port 73 under vacuum conditions, and the filling rate is controlled at 40% to 60%. Heat exchange fins 72 are arranged between the pulsating heat pipes 71, and the surface of the heat exchange fins 72 is provided with a secondary structure, such as Figure 5As shown, compared with the traditional fin design, this surface structure can promote local turbulence with a smaller pressure drop, strengthen the heat exchange between air and fins, and make the heat transfer more sufficient. When there is a temperature difference between the exhaust air temperature and the fresh air temperature, the working fluid in the pulsating heat pipe 71 will undergo gas-liquid phase change, and under the action of the phase change pressure, a self-excited oscillating flow will be formed inside the pipeline to achieve efficient heat transfer. In winter, heat is transferred from the exhaust air duct 3 to the fresh air duct 2 to preheat the fresh air; in summer, heat is transferred from the fresh air duct 2 to the exhaust air duct 3 to pre-cool the fresh air.

[0040] This device can be linked with temperature and humidity sensors to detect the indoor and outdoor temperature and humidity, and automatically optimize the fresh air and exhaust air flow through the air flow regulating device. Specifically, the greater the temperature difference at both ends of the pulsating heat pipe, the better the heat transfer performance. Therefore, when the outdoor temperature is too low or too high, that is, when the indoor and outdoor temperature difference is large, the device will appropriately reduce the exhaust air and fresh air flow to reduce energy consumption and stabilize the heat recovery efficiency at the same time. The air flow regulating device can automatically adjust the fresh air and exhaust air flow according to the changes in indoor and outdoor temperature and humidity to optimize the heat recovery efficiency and maintain the indoor air quality.

[0041] Through technical means such as pulsating heat pipe heat exchange, latent heat recovery of moisture-permeable and air-blocking film, and intelligent flow regulation, the present invention realizes efficient fresh air waste heat recovery, reduces building energy consumption, and improves air quality. This device has a compact structure and strong adaptability, and can be widely used in the fields of heating, ventilation, air conditioning systems and waste heat recovery.

[0042] The working principle of the fresh air waste heat recovery device of the present invention is as follows:

[0043] (1) Air flow path: Indoor exhaust air is discharged through the exhaust air duct, and outdoor fresh air enters the room through the fresh air duct. The two ducts are separated by a moisture-permeable and air-blocking film. The moisture-permeable and air-blocking film can prevent the direct mixing of fresh air and exhaust air, but allows water vapor to pass through to recover the latent heat in the exhaust air.

[0044] (2) Pulse heat pipe heat transfer: The pulsating heat pipe heat exchanger is set in the center of the air duct. Under vacuum conditions, the pipe is filled with a low-boiling-point liquid working medium (such as R134a, 1234yf, and R1233zd, etc., depending on the working environment and requirements). The boiling point of the working medium changes with the pressure inside the pipe. When there is a temperature difference between the exhaust air temperature and the fresh air temperature, the working medium in the capillary tube is heated and evaporated, and self-excited oscillating flow is generated under the drive of the gas-liquid phase change, thus realizing efficient heat transfer. In winter, heat is transferred from the exhaust air duct to the fresh air duct to preheat the fresh air; while in summer, the heat transfer direction is opposite, pre-cooling the fresh air, thereby improving the energy efficiency of indoor air conditioning. At the same time, due to the dense fins provided between the parallel pipes of the pulsating heat pipe, these fins can increase the heat transfer area and enhance the local turbulence through the secondary structure on the fin surface, making the heat transfer between the air and the fins more sufficient, thus improving the efficiency of heat transfer to the inside of the pulsating heat pipe. This efficient heat transfer structure enables the device of the present invention to achieve higher heat transfer efficiency at a smaller volume compared with traditional heat exchangers, with a faster response speed and stronger ability to adapt to dynamic temperature changes.

[0045] (3) Humidity regulation and anti-condensation: The moisture-permeable and airtight film allows water vapor to pass through, thereby reducing the humidity difference between the fresh air and the exhaust air and reducing the risk of condensate generation. This characteristic enables the device of the present invention to effectively prevent frosting during winter operation and avoid a decrease in heat transfer efficiency.

[0046] (4) Air quality guarantee: The fresh air entering the room first passes through the fresh air filter to remove particulate matter and harmful substances in the air, ensuring air cleanliness. The air flow regulating device can optimize the air volume according to real-time environmental changes, achieving a balance between heat transfer efficiency and air quality.

[0047] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all the details in detail, nor limit the invention to the specific embodiments described. Obviously, many modifications and changes can be made according to the content of this specification. These embodiments are selected and specifically described in this specification to better explain the principle and practical application of the present invention, so that those skilled in the art can well understand and utilize the present invention. The present invention is only limited by the claims and their full scope and equivalents.

Claims

1. A fresh air waste heat recovery device based on a pulsating heat pipe, characterized in that, The device includes: Chassis (1); The inside of the chassis (1) is divided into a fresh air duct (2) and an exhaust air duct (3) which are parallel to each other by an air duct partition (6); the air duct partition (6) comprises a moisture-permeable and gas-blocking film (62); A pulsating heat pipe heat exchanger (7) is arranged in the chassis (1), and the pulsating heat pipe heat exchanger (7) is connected to the fresh air duct (2) and the exhaust air duct (3).

2. The fresh air waste heat recovery device based on a pulsating heat pipe according to claim 1, wherein A fresh air filter (4) is installed at the entrance of the fresh air duct (2); it comprises a shutter filter screen (41) and a polymer filter pad (42).

3. The fresh air waste heat recovery device based on a pulsating heat pipe according to claim 1, characterized in that An exhaust fan (5) is provided at the entrance of the exhaust air duct (3).

4. The fresh air waste heat recovery device based on a pulsating heat pipe according to claim 1, wherein, The moisture-permeable and gas-blocking membrane (62) is fixed between the fresh air duct (2) and the exhaust air duct (3) by means of a slot assembly.

5. The fresh air waste heat recovery device based on a pulsating heat pipe according to claim 1, characterized in that, Check valves (9) are provided at the outlets of the fresh air duct (2) and the exhaust air duct (3).

6. The fresh air waste heat recovery device based on a pulsating heat pipe according to claim 1, characterized in that, The pulsating heat pipe heat exchanger (7) is composed of a "harmonica-type" pulsating heat pipe (71), which contains dozens of parallel channels inside and forms a loop through multiple bends, and has a filling port (73).

7. The fresh air waste heat recovery device based on a pulsating heat pipe according to claim 1, wherein, A pulsating heat pipe buckle assembly is arranged between the two groups of moisture-permeable and gas-blocking films (62) to connect the pulsating heat pipe heat exchanger (7) to the moisture-permeable and gas-blocking films (62).

8. The fresh air waste heat recovery device based on a pulsating heat pipe according to claim 1, characterized in that, Heat exchange fins are arranged between the pulsating heat pipes (71).

9. The fresh air waste heat recovery device based on a pulsating heat pipe according to claim 1, characterized in that, The surface of the heat exchange fin (72) is provided with a secondary structure.

10. The fresh air waste heat recovery device based on a pulsating heat pipe according to claim 1, wherein, The device is equipped with temperature and humidity sensors and air flow control devices. It uses the temperature and humidity sensors to detect indoor and outdoor temperature and humidity, and adjusts the fresh air and exhaust air flow according to the indoor and outdoor temperature and humidity through the air flow control device.

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