Two-stage filtering and air inlet system of air energy heat pump water unit

Abstract

According to the two-stage filtering and air inlet system of the air energy heat pump water unit, by introducing the dehumidification heat exchanger, air can be dehumidified in a low-temperature environment, and the freezing risk is reduced. Comprising fins, a first heat exchange pipe and a second heat exchange pipe, and the first heat exchange pipe and the second heat exchange pipe penetrate through the fins to conduct heat exchange. The evaporator is located on the rear side of the dehumidification heat exchanger and is sequentially connected with a compressor, a condenser and an expansion valve through a refrigerant pipeline; the medium pipeline communicates with the second heat exchange pipe and communicates with the refrigerant pipeline to form a loop; the dehumidification heat exchanger is of a two-stage dehumidification filtering structure, pretreatment and deep dehumidification of air are achieved, in the low-temperature environment, through cooperative work of the medium pipeline control valve system, the auxiliary water tank and the electric heater, it is ensured that the surface temperature of the dehumidification heat exchanger system is larger than 0 DEG C at the ultralow temperature, and the freezing risk is avoided.

Description

Technical Field

[0001] This invention relates to the field of air source heat pump technology, and more particularly to a two-stage filtration and air intake system for an air source heat pump water unit. Background Technology

[0002] Air source heat pumps (ASHPs), as a highly efficient and energy-saving hot water supply technology, have been widely used in heating and hot water systems of residential and commercial buildings. Their principle is to utilize the heat energy in the ambient air, transferring and amplifying this heat energy through refrigerant circulation. Compared to traditional electric or gas heating, they have significant energy efficiency advantages (COP values ​​often reach 3-5 or higher). However, existing technologies face a series of inherent defects in actual operation, especially in low-temperature and high-humidity environments, limiting their reliability and energy efficiency performance. One such defect is icing in low-temperature and high-humidity environments. Traditional air source heat pump systems typically use a single evaporator for air heat exchange. When the ambient temperature is below 5°C and the humidity is high, moisture in the air easily condenses and freezes on the evaporator surface, forming a frost layer. This not only increases thermal resistance and reduces heat exchange efficiency (COP values ​​can decrease by 20%-40%), but may also cause the compressor to frequently start defrosting cycles, resulting in system downtime, a surge in energy consumption, and equipment wear. Existing solutions such as electric defrosting or reverse circulation defrosting, while alleviating icing, suffer from limitations including slow response, high energy consumption (additional power consumption reaching 15%-30% of total system energy consumption), and a narrow temperature adaptability range (only applicable to environments above -5℃). The lack of dehumidification capacity means that excessive humidity during the air intake process of air-source heat pumps not only exacerbates the risk of icing but also reduces overall system energy efficiency and indoor air quality. Current technologies largely rely on simple filters or preheating devices for humidity control, but these methods cannot achieve precise dehumidification: filters can only intercept large particulate pollutants and are ineffective against water vapor; while preheating devices can raise the air temperature, they are energy-intensive and cannot maintain dew point temperature control, resulting in insufficient water evaporation from the evaporator surface. Summary of the Invention

[0003] In view of the above situation and to overcome the defects of the prior art, the purpose of this invention is to provide a two-stage filtration and air intake system for an air source heat pump water unit. By introducing a dehumidifying heat exchanger and increasing its synergistic work with the medium pipeline control valve system, auxiliary water tank and electric heater, it can dehumidify the air in low-temperature environments, reduce the risk of icing and significantly improve energy efficiency.

[0004] The solution is a two-stage filtration and air intake system for an air-source heat pump water unit, including a housing, characterized in that it further includes: A dehumidifying heat exchanger that maintains the dew point temperature of the air passing through it includes fins, a first heat exchange tube and a second heat exchange tube through which heat is exchanged. The evaporator is located behind the dehumidifying heat exchanger, and it is connected in sequence to the compressor, condenser, and expansion valve via refrigerant piping. The main hot water tank has a condenser that extends into it and heats the water inside. It is connected to the indoor hot water utilization system. The medium pipeline connects to the second heat exchange tube and is connected to the refrigerant pipeline to form a loop. The upstream end of the medium pipeline is located between the expansion valve and the evaporator, and the downstream end of the medium pipeline is located between the evaporator and the compressor. A first control valve is provided on the medium pipeline, which is located between the upstream connection point of the medium pipeline and the refrigerant pipeline and the dehumidification heat exchanger. A second control valve is provided on the refrigerant pipeline, which is located between the upstream connection point of the medium pipeline and the refrigerant pipeline and the evaporator. The auxiliary water tank is connected to the first heat exchange tube and the main heat exchange tank in sequence through the auxiliary water pipe to form a closed loop; it is equipped with an auxiliary heat exchanger, which is connected to the refrigerant pipeline through the auxiliary medium pipe. The upstream and downstream ends of the auxiliary medium pipe connected to the refrigerant pipeline are located between the compressor and the condenser. Preferably, a third control valve is installed on the auxiliary medium pipe, and a fourth control valve is installed on the refrigerant pipe. The third control valve is located between the upstream end connection point of the auxiliary medium pipe and the refrigerant pipe and the auxiliary heat exchanger, and the fourth heat exchange valve is located between the upstream end connection point and the downstream end connection point of the auxiliary medium pipe and the refrigerant pipe.

[0005] Preferably, the auxiliary water tank is equipped with an electric heater.

[0006] Preferably, an evaporator is fixed on both the left and right sides of the shell, and a dehumidifying heat exchanger is provided on the outside of each evaporator. The dehumidifying heat exchanger and the evaporator on the same side are connected by a ventilation pipe. At least one air outlet is provided at the bottom of the shell, and an air outlet fan is installed on the shell inside the air outlet.

[0007] Preferably, the width of the evaporator is the same as the width of the dehumidifying heat exchanger, and its height is greater than the height of the dehumidifying heat exchanger. The center of the evaporator and the center of the dehumidifying heat exchanger are at the same height, and the cross-section of the middle part of the ventilation pipe is trapezoidal.

[0008] Preferably, the end of the ventilation duct facing the dehumidifying heat exchanger is provided with a rectangular connecting part, and a mounting frame is fixed inside it. Multiple guide plates are provided in the mounting frame. The guide plates are evenly distributed along the side perpendicular to and parallel to the ventilation duct. The guide plates are composed of multiple bent structures with both ends located on the same plane. The height of the bent plates increases from the dehumidifying heat exchanger towards the evaporator and both ends are in contact with the end of the ventilation duct. The end of the bent plate facing the dehumidifying heat exchanger is provided with a rectangular insertion part. The mounting frame is provided with an insertion groove. The insertion part is inserted into the insertion groove and secured to the mounting frame.

[0009] Preferably, the guide plate has a flow divider installed in the channel on the side facing the evaporator. The flow divider has a number of flow divider holes evenly distributed on it. The flow divider and the guide plate are spaced apart, and there is at least one flow guide fan between the flow divider and the guide plate.

[0010] Preferably, the dehumidifying heat exchanger has a filter screen on the side away from the evaporator.

[0011] The beneficial effects of this invention are as follows: The dual-stage dehumidification and filtration architecture of the dehumidification heat exchanger of this invention realizes air pretreatment and deep dehumidification. In the normal temperature dehumidification mode (temperature > 5℃), the surface temperature of the dehumidification heat exchanger is maintained at 8-10℃. When the air is pre-cooled to the dew point, moisture is precipitated, reducing the condensation droplets on the evaporator surface. In low-temperature environments, through the coordinated work of the medium pipeline control valve system, auxiliary water tank and electric heater, it is ensured that the surface temperature of the dehumidification heat exchanger system is greater than 0℃ at ultra-low temperatures, avoiding the risk of freezing. The bent guide plate makes the airflow evenly diffuse from the small cross section to the large cross section, covering the entire heat exchange surface of the evaporator. The guide fan creates turbulence between the flow dividers and works with the airflow plate to eliminate airflow dead zones and improve the heat exchange uniformity of the evaporator. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the pipeline connections of the various components of the present invention.

[0013] Figure 2 This is a schematic diagram of the overall structure of the present invention.

[0014] Figure 3 For the present invention Figure 2 A three-dimensional schematic diagram.

[0015] Figure 4 This is a schematic diagram of the guide plate of the present invention.

[0016] Figure 5 For the present invention Figure 4 A three-dimensional schematic diagram.

[0017] In the diagram: 1. Shell; 2. Dehumidifying heat exchanger; 3. Evaporator; 4. First heat exchange tube; 5. Second heat exchange tube; 6. Compressor; 7. Condenser; 8. Expansion valve; 9. Main hot water tank; 10. Refrigerant pipeline; 11. Medium pipeline; 12. Auxiliary water tank; 13. Water pump; 14. Ventilation duct; 15. Air outlet; 16. Exhaust fan; 17. Motor; 18. Mounting frame; 19. Baffle plate; 20. Diverter plate; 21. Guide fan; 22. Filter screen; 23. First control valve; 24. Second control valve; 25. Third control valve; 26. Third control valve; 27. Auxiliary heat exchanger; 28. Auxiliary medium pipeline; 29. ​​Electric heater. Detailed Implementation

[0018] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0019] Depend on Figures 1 to 5 Provided is a two-stage filtration and air intake system for an air source heat pump water unit, comprising a housing 1, characterized in that it further comprises: The dehumidifying heat exchanger 2 maintains the dew point temperature of the air passing through it, and includes fins, a first heat exchange tube 4 and a second heat exchange tube 5 through which heat is exchanged. Evaporator 3 is located behind dehumidifying heat exchanger 2, and is connected in sequence to compressor 6, condenser 7 and expansion valve 8 via refrigerant pipeline 10. The main hot water tank 9 has a condenser 7 that extends into it and heats the water inside. It is connected to the indoor hot water utilization system. Medium pipeline 11 connects to the second heat exchange tube and is connected to refrigerant pipeline 10 to form a loop. The upstream end of medium pipeline 11 is located between expansion valve 8 and evaporator 3, and the downstream end of medium pipeline 11 is located between evaporator 3 and compressor 6. The medium pipeline 11 is provided with a first control valve 23, which is located between the upstream connection point of the medium pipeline 11 and the refrigerant pipeline 10 and the dehumidification heat exchanger 2. The refrigerant pipeline 10 is provided with a second control valve 24, which is located between the upstream connection point of the medium pipeline 11 and the refrigerant pipeline 10 and the evaporator 3.

[0020] The auxiliary water tank 12 is connected to the first heat exchange tube 4 and the main heat exchange water tank 9 in sequence through the auxiliary water pipe to form a closed loop. It is equipped with an auxiliary heat exchanger 27, which is connected to the refrigerant pipeline 10 through the auxiliary medium pipe 28. The upstream and downstream ends of the auxiliary medium pipe 28 connected to the refrigerant pipeline 10 are located between the compressor 6 and the condenser. A water pump 13 is installed on the auxiliary water pipe.

[0021] A third control valve is installed on the auxiliary medium pipe 28, and a fourth control valve is installed on the refrigerant pipe 10. The third control valve is located between the upstream end of the auxiliary medium pipe 28 and the refrigerant pipe 10 and the auxiliary heat exchanger 2727. The fourth heat exchange valve is located between the upstream end of the auxiliary medium pipe 28 and the refrigerant pipe 10 and the downstream end.

[0022] The auxiliary water tank 12 is equipped with an electric heater 29.

[0023] The air source heat pump water unit's two-stage filtration and air intake system can operate in both normal temperature dehumidification mode and low temperature active dehumidification mode.

[0024] When the air temperature exceeds 5 degrees Celsius, the second control valve opens, the first control valve 23 adjusts proportionally, the third control valve closes, and the fourth control valve opens, allowing the refrigerant pipeline to flow directly. This maintains the surface temperature of the dehumidifying heat exchanger 2 (i.e., the heat exchange fins) at 5-10 degrees Celsius. As the air is pre-cooled to its dew point on the heat exchanger surface, moisture is released, reducing the humidity entering the evaporator 3 and minimizing condensation on the evaporator 3, thus improving its heat exchange efficiency. Even when the air temperature is higher than 10 degrees Celsius, condensation on the evaporator 3 is minimal. In this mode, the dehumidifying heat exchanger 2 functions as a heat exchanger between the evaporator 3 and the outside environment.

[0025] In the low-temperature active dehumidification mode, the first control valve 23 is closed, the second control valve 24 is fully open, the third control valve is closed, and the fourth control valve is open.

[0026] When the air temperature is between -5°C and 5°C, water pump 13 is activated, and hot water from the main hot water tank 9 is pumped into the first heat exchange tube 4. The surface temperature of the dehumidifying heat exchanger 2 is maintained at 5-8°C. Low-temperature air is then pre-dehumidified to reduce the humidity of the air passing through the evaporator 3, preventing the evaporator 3 from freezing due to low temperature and high humidity. The amount of hot water entering the first heat exchange tube 4 is adjusted according to the surface temperature of the dehumidifying heat exchanger 2, thereby regulating the surface temperature of the dehumidifying heat exchanger 2.

[0027] When the air temperature is between -15°C and -5°C, the third control valve opens. By adjusting the opening ratio of the fourth control valve, the ratio of the compressed high-temperature refrigerant between the main circuit and the auxiliary circuit is controlled, thereby controlling the temperature of the auxiliary water tank 12, raising the temperature of the auxiliary water tank 12 to 50-60°C. At the same time, the water pump is adjusted to maximize the water flow into the first heat exchange tube 4. The hot water circulates to the dehumidification heat exchanger 2, maintaining the surface temperature of the dehumidification heat exchanger 2 at 3-5°C, forcing air dehumidification, and preventing the evaporator 3 from freezing, which would affect the heat exchange effect.

[0028] When the air temperature is below -15 degrees Celsius, the third control valve opens and the fourth control valve closes, turning on the electric heater 29 of the auxiliary water tank 12 to maintain the temperature of the auxiliary water tank 12 at 60-70 degrees Celsius and keep the surface temperature of the dehumidifying heat exchanger 2 above 0 degrees Celsius, ensuring basic dehumidification capacity and preventing the system from freezing.

[0029] An evaporator 3 is fixed on both the left and right sides of the housing 1. A dehumidifying heat exchanger 2 is provided on the outside of each evaporator 3. The dehumidifying heat exchanger 2 and the evaporator 3 on the same side are connected by a ventilation pipe 14. At least one air outlet 15 is provided at the bottom of the housing 1. An air outlet 16 installed on the housing 1 is provided inside the air outlet 15. Evaporator 3 is fixedly installed on shell 1. Ventilation pipe 14 is fixedly connected to the shell of evaporator 3. The cross-section of the connection between ventilation pipe 14 and evaporator 3 completely covers the ventilation surface of evaporator 3. The shell of dehumidifier heat exchanger is connected to the other end of ventilation pipe 14. The cross-section of the connection between ventilation pipe 14 and evaporator 3 completely covers the ventilation surface of dehumidifier heat exchanger 2. External cold air is first heated to the dew point temperature of water vapor by dehumidifier heat exchanger 2, and then enters evaporator 3 through ventilation pipe 14 for heat exchange. Then, the air is forced out of shell 1 by exhaust fan 16. Exhaust fan 16 works to exhaust the air in shell 1, forming a negative pressure in shell 1. Then, air enters shell 1 from ventilation pipes 14 on both sides of shell 1 to complete the air circulation. The air is heated by evaporator 3 at evaporator 3, completing the heating process of evaporator 3. The blower 16 includes a blower mounting bracket fixed to the inner side of the upper part of the housing 1, a fan blade shaft, blades mounted on the fan blade shaft, and a motor 17 fixed to the blower mounting bracket. The output shaft of the motor 17 is coaxially and fixedly connected to the fan blade shaft. An air outlet duct fixed to the housing 1 is provided above the air outlet 15. To increase the air circulation rate, two air outlets 15 are provided, symmetrically arranged on the upper part of the housing 1, and two blowers 16 are also provided. A water collection tank is provided at the bottom of the dehumidifying heat exchanger 2 to collect water droplets falling from the fins of the dehumidifying heat exchanger 2. The surface of the water collection tank is made of a hydrophobic material, and the water collection tank is provided with a drain hole so that water droplets entering the water collection tank are quickly discharged.

[0030] The evaporator 3 has the same width as the dehumidifying heat exchanger 2, but its height is greater than that of the dehumidifying heat exchanger 2. The center of the evaporator 3 is at the same height as the center of the dehumidifying heat exchanger 2. The cross-section of the middle part of the ventilation pipe 14 is trapezoidal. The two ends of the ventilation pipe 14 are square and extend outward to form flanges. The flanges at both ends of the ventilation pipe 14 are used to install and connect to the dehumidifying heat exchanger 2 or the evaporator 3. That is, the outer side of the evaporator 3 and the outer side of the dehumidifying heat exchanger 2 are provided with mounting plates that cooperate with the flanges of the pipe. The flanges and mounting plates are fixedly connected by bolts. The ventilation pipe 14 installs and supports the dehumidifying heat exchanger 2, and the weight of the dehumidifying heat exchanger 2 is borne by the ventilation pipe 14. To ensure sufficient heat exchange between the evaporator 3 and the air passing through the dehumidifier heat exchanger 2, the heat exchange area of ​​the evaporator 3 is relatively large. In order to keep the structure of the ventilation pipe 14 simple and to ensure that the air passing through the dehumidifier heat exchanger 2 can pass through the evaporator 3 evenly, the evaporator 3 and the dehumidifier heat exchanger 2 are set to have the same width but different heights, and the centers of the dehumidifier heat exchanger 2 and the evaporator 3 are located at the same height.

[0031] The ventilation duct 14 has a rectangular connecting part at one end facing the dehumidifying heat exchanger, and a mounting frame 18 is fixed inside it. Multiple guide plates 19 are arranged inside the mounting frame 18, evenly distributed along a side perpendicular to and parallel to the ventilation duct 14. The guide plates 19 are composed of multiple bent sections with both ends on the same plane. The height of the bent plates increases from the dehumidifying heat exchanger 2 towards the evaporator 3, and both ends contact the end of the ventilation duct 14. A rectangular insertion part is provided at the end of the bent plate facing the dehumidifying heat exchanger 2. An insertion slot is provided inside the mounting frame 18, and the insertion part is inserted into the slot and secured to the mounting frame 18. Multiple threaded holes are provided inside the mounting frame 18. Multiple mounting holes for the guide plates 19 are provided at the end of the ventilation duct 14 facing the dehumidifying heat exchanger 2, which mate with the threaded holes. Bolts pass through the mounting holes of the guide plates 19 and are screwed into the threaded holes, thus fixing the mounting frame 18 inside the ventilation duct 14 and consequently fixing the guide plates 19 inside the ventilation duct 14. As air flows from the small port to the large port of the ventilation duct 14, it then flows through the mounting frame 18 and into the gaps between the various guide plates 19. After being obstructed by the bends of the guide plates 19, the air expands from the middle of the gaps between the guide plates 19 to both the upper and lower ends. As the cross-section of the duct increases, the air can diffuse and distribute evenly, and then pass through the evaporator 3 more evenly, resulting in better heat exchange with the evaporator 3. This reduces the poor heat exchange effect of the evaporator 3 caused by the small amount of air passing through it.

[0032] The guide plate 19 has a flow divider 20 installed in the channel on the side facing the evaporator 3. The flow divider 20 has a number of flow divider holes evenly distributed on it. The flow divider 20 and the guide plate 19 are spaced apart, and there is at least one flow guide fan 21 between the flow divider 20 and the guide plate 19. Two flow guide fans 21 are symmetrically installed on the flow divider 20. The flow divider 20 has a flow guide shaft on the side facing the guide plate 19. The flow guide fan 21 is rotatably mounted on the flow guide shaft. The flow guide fan 21 consists of blades and a blade mounting part. The blade mounting part has at least two blades evenly distributed on it, and the flow guide mounting part is rotatably mounted on the flow guide shaft. The air passing through the guide plate 19 drives the flow guide fan 21 to rotate, forming turbulence in the space between the flow divider 20 and the guide plate 19, making the air distribution more uniform. Then, the air flows out evenly through the evenly distributed flow divider holes on the flow divider 20 and enters the evaporator 3 for heat exchange.

[0033] The dehumidifier heat exchanger 2 has a filter screen 22 on the side opposite to the evaporator 3. It is mainly used to filter dust from the air entering the dehumidifier heat exchanger. The bent structure of the guide plate 19 not only evenly distributes the airflow but also further filters impurities in the air, preventing dust from accumulating on the evaporator 3 and causing a decrease in the heat exchange efficiency. The heat exchange fins of the dehumidifier heat exchanger 2 also adsorb dust, and the condensate on their surface carries the dust onto the fins into the water collection tank below.

[0034] The beneficial effects of this invention are as follows: The dual-stage dehumidification and filtration architecture of the dehumidification heat exchanger of this invention realizes air pretreatment and deep dehumidification. In the normal temperature dehumidification mode (temperature > 5℃), the surface temperature of the dehumidification heat exchanger is maintained at 8-10℃. When the air is pre-cooled to the dew point, moisture is precipitated, reducing the condensation droplets on the evaporator surface. In low temperature environments, through the coordinated work of the medium pipeline control valve system, auxiliary water tank and electric heater, it is ensured that the surface temperature of the dehumidification heat exchanger system is greater than 0℃ at ultra-low temperatures, avoiding the risk of freezing.

[0035] The embodiments described above are not intended to limit the scope of the present invention. Any modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the inventive concept should be included within the scope of protection defined by the claims of the present invention.

Claims

1. A two-stage filtration and air intake system for an air-source heat pump water unit, comprising a housing (1), characterized in that, Also includes: The dehumidifying heat exchanger (2) maintains the dew point temperature of the air passing through it, and includes fins, a first heat exchange tube (4) and a second heat exchange tube (5) through which heat is exchanged. The evaporator (3) is located behind the dehumidifying heat exchanger (2), and is connected in sequence to the compressor (6), condenser (7) and expansion valve (8) via the refrigerant pipeline (10). The main hot water tank (9) has a condenser (7) that extends into it and heats the water inside. It is connected to the indoor hot water utilization system. Medium pipeline (11) is connected to the second heat exchange tube (5) and connected to the refrigerant pipeline (10) to form a loop. The upstream end of the medium pipeline (11) connected to the refrigerant pipeline (10) is located between the expansion valve (8) and the evaporator (3), and the downstream end of the medium pipeline (10) connected to the refrigerant pipeline (10) is located between the evaporator (3) and the compressor (6). The medium pipeline (11) is provided with a first control valve (23). The first control valve (23) is located between the upstream connection of the medium pipeline (11) and the refrigerant pipeline (10) and the dehumidifying heat exchanger (2). The refrigerant pipeline (10) is provided with a second control valve (24). The second control valve (24) is located between the upstream connection of the medium pipeline (11) and the refrigerant pipeline (10) and the evaporator (3). The auxiliary water tank (12) is connected to the first heat exchange tube (4) and the main heat exchange water tank (9) in sequence through the auxiliary water pipe to form a closed loop. It is equipped with an auxiliary heat exchanger (27), which is connected to the refrigerant pipeline (10) through the auxiliary medium pipe (28). The upstream and downstream ends of the auxiliary medium pipe (28) connected to the refrigerant pipeline (10) are located between the compressor (6) and the condenser (7).

2. The dual-stage filtration and air intake system of the air-source heat pump water unit according to claim 1, characterized in that, A third control valve is installed on the auxiliary medium pipe (28), and a fourth control valve is installed on the refrigerant pipe (10). The third control valve is located between the upstream end of the auxiliary medium pipe (28) and the refrigerant pipe (10) and the auxiliary heat exchanger (27). The fourth heat exchange valve is located between the upstream end of the auxiliary medium pipe (28) and the refrigerant pipe (10) and the downstream end.

3. The dual-stage filtration and air intake system of the air-source heat pump water unit according to claim 2, characterized in that, The auxiliary water tank (12) is equipped with an electric heater (29).

4. The dual-stage filtration and air intake system of the air-source heat pump water unit according to claim 2, characterized in that, An evaporator (3) is fixed on both the left and right sides of the housing (1). A dehumidifying heat exchanger (2) is provided on the outside of the evaporator (3). The dehumidifying heat exchanger (2) and the evaporator (3) on the same side are connected by a ventilation pipe (14). At least one air outlet (15) is provided at the bottom of the housing (1). An air blower (16) installed on the housing (1) is provided inside the air outlet (15).

5. The dual-stage filtration and air intake system of the air-source heat pump water unit according to claim 4, characterized in that, The width of the evaporator (3) is the same as the width of the dehumidifying heat exchanger (2), and its height is greater than that of the dehumidifying heat exchanger (2). The center of the evaporator (3) and the center of the dehumidifying heat exchanger (2) are at the same height. The cross-section of the middle part of the ventilation pipe (14) is trapezoidal.

6. The dual-stage filtration and air intake system of the air-source heat pump water unit according to claim 5, characterized in that, The ventilation pipe (14) has a rectangular connecting part at one end facing the dehumidifying heat exchanger (2), and a mounting frame (18) is fixed inside it. Multiple guide plates (19) are set inside the mounting frame (18). The guide plates (19) are evenly distributed along the side perpendicular to and parallel to the ventilation pipe (14). The guide plates (19) are composed of multiple bent structures and their two ends are located on the same plane. The height of the bent plates increases from the dehumidifying heat exchanger (2) to the evaporator (3), and both ends are in contact with the end of the ventilation pipe (14). The bent plate has a rectangular insertion part at one end facing the dehumidifying heat exchanger (2). The mounting frame (18) has an insertion groove. The insertion part is inserted into the insertion groove and fixed on the mounting frame (18).

7. The dual-stage filtration and air intake system of the air-source heat pump water unit according to claim 6, characterized in that, The guide plate (19) has a flow divider (20) installed in the channel on the side facing the evaporator (3). The flow divider (20) has a number of flow divider holes evenly distributed on it. The flow divider (20) and the guide plate (19) are spaced apart. There is at least one flow guide fan (21) between the flow divider (20) and the guide plate (19).

8. The dual-stage filtration and air intake system of the air-source heat pump water unit according to claim 4, characterized in that, The dehumidifying heat exchanger (2) is provided with a filter screen (22) on the side away from the evaporator (3).

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