A fresh air heat exchange device for utilizing condensate waste cooling, and an air conditioner

Abstract

This invention relates to a fresh air heat exchange device and air conditioner that utilizes condensate waste cooling, comprising: a condensate pipe connected to the condensate drain outlet of an outdoor unit; a heat exchange pipe, one end of which is used to receive outdoor fresh air, and the other end of which is used to output the outdoor fresh air into the room, the heat exchange pipe having a longitudinally encircling structure, the outlet of the condensate pipe being arranged on the upper side of each top of the heat exchange pipe, so that condensate flows down the heat exchange pipe after being discharged from the condensate pipe to each top of the heat exchange pipe; and a housing for housing the heat exchange pipe, the housing having an indoor exhaust air inlet and an indoor exhaust air outlet, the indoor exhaust air inlet being connected to indoor exhaust air, so that indoor exhaust air enters the housing from the indoor exhaust air inlet, exchanges heat with the heat exchange pipe and condensate, and is then discharged to the outside from the indoor exhaust air outlet.

Description

Technical Field

[0001] This invention relates to the field of heat exchange devices, specifically to a fresh air heat exchange device and an air conditioner that utilizes residual cooling of condensate. Background Technology

[0002] Air conditioning includes an internal circulation system and an external circulation system. The internal circulation system cools the indoor air to produce cooler air, while the external circulation system brings outdoor air into the room to keep indoor air levels such as carbon dioxide below a certain threshold.

[0003] Air conditioner's internal circulation system generates a significant amount of condensate from the indoor unit during operation. The condensate temperature is typically between 11 and 13°C, far below the ambient temperature. Current air conditioners generally discharge this condensate directly without recycling it, resulting in energy waste. Alternatively, they collect the condensate and perform a simple heat exchange with the indoor or outdoor air to recover residual cooling. These methods or structures do not fully utilize the residual cooling capacity of the condensate, leading to further energy waste.

[0004] The purpose of this invention is to design a fresh air heat exchange device and air conditioner that utilizes residual cooling of condensate to address the problems existing in the prior art. Summary of the Invention

[0005] In view of the problems existing in the prior art, the present invention provides a fresh air heat exchange device and air conditioner for utilizing condensate waste cooling, which can effectively solve at least one of the problems existing in the prior art.

[0006] The technical solution of this invention is:

[0007] A fresh air heat exchange device for utilizing condensate waste cooling includes:

[0008] The condensate drain pipe is connected to the condensate drain outlet of the outdoor unit.

[0009] The heat exchange tube has one end for connecting to outdoor fresh air and the other end for outputting the outdoor fresh air into the room. The heat exchange tube has a longitudinally encircling structure. The outlet of the condensate pipe is located on the upper side of each top of the heat exchange tube, so that after the condensate is discharged from the condensate pipe, it flows to each top of the heat exchange tube and then flows downward along the heat exchange tube.

[0010] The housing is used to house the heat exchange tubes. The housing is provided with an indoor exhaust inlet and an indoor exhaust outlet. The indoor exhaust inlet is connected to the indoor exhaust air, so that the indoor exhaust air enters the housing from the indoor exhaust inlet, exchanges heat with the heat exchange tubes and condensate, and is then discharged to the outside from the indoor exhaust outlet.

[0011] Furthermore, the indoor exhaust inlet and the indoor exhaust outlet are diagonally arranged on the housing to extend the circulation path of the indoor exhaust and improve the heat exchange efficiency between the indoor exhaust and the heat exchange tube and condensate.

[0012] Furthermore, the heat exchange tube has corrugations on its outer surface, and the inclination angle of the corrugations is opposite to the flow path of the indoor exhaust air.

[0013] Furthermore, the outlet of the condensate pipe is connected to the top of the heat exchange tube by a wet film, so that after the condensate is discharged, it is led to the top of the heat exchange tube through the wet film and forms a water film on the outer wall of the heat exchange tube.

[0014] Furthermore, the corrugation inclination of the heat exchange tube is defined as i, tan(i) = 0.75~0.85; the tube diameter of the heat exchange tube is 250~350mm; and the air velocity of the indoor exhaust is configured as 4.5~5.5m / s.

[0015] Furthermore, the bottom of the housing is inclined downwards towards the end of the heat exchange tube that outputs the outdoor fresh air into the room, in order to collect condensate.

[0016] Furthermore, the housing is equipped with a wet membrane filter at the end of the heat exchange tube that outputs the outdoor fresh air into the room. The wet membrane filter is driven by a driving mechanism, which can drive the wet membrane filter to contact the condensate at the bottom of the housing, and / or the driving mechanism can drive the wet membrane filter to cover the end of the heat exchange tube that outputs the outdoor fresh air into the room, and / or the driving mechanism can drive the wet membrane filter to avoid the end of the heat exchange tube that outputs the outdoor fresh air into the room.

[0017] Furthermore, it includes a humidity sensor and a control system, wherein the humidity sensor is used to acquire indoor humidity.

[0018] When the indoor humidity is lower than the first threshold, the control system controls the drive mechanism to drive the wet membrane filter to contact the condensate at the bottom of the box, and then drives the wet membrane filter to cover the end of the heat exchange tube that outputs the outdoor fresh air into the room;

[0019] When the indoor humidity is higher than a first threshold, the control system controls the drive mechanism to drive the wet membrane filter to bypass the heat exchange tube and output the outdoor fresh air into the room.

[0020] Furthermore, the driving mechanism includes an electromagnet and a spring. The electromagnet can move upward under the control of the control system. The wet membrane filter is connected to the lower end of the electromagnet, thereby driving the wet membrane filter to move upward. The spring is connected to the lower end of the wet membrane filter, so that the wet membrane filter can be pulled downward after the electromagnet is de-energized. After the wet membrane filter moves upward, it covers the end of the heat exchange tube that outputs the outdoor fresh air into the room. After the wet membrane filter moves downward, it contacts the condensate at the bottom of the housing.

[0021] An air conditioner comprising a fresh air heat exchange device for utilizing residual cooling of condensate as described in any one of the claims.

[0022] Therefore, the present invention provides the following effects and / or advantages:

[0023] (1) After the condensate from the indoor air conditioner is recovered, it is led to the threaded heat exchange copper tube through the condensate pipe and the wet film, forming a water film on the outer wall of the heat exchange tube. The water in the water film state can cover the corrugated surface of the heat exchange tube more evenly and thinly, and flow slowly downward along the surface of the heat exchange tube under the action of gravity. The technical effect is that it can increase the contact area between the condensate and the corrugation, and prevent the condensate from accumulating and flowing downward.

[0024] (2) The corrugation angle of the heat exchange tube is opposite to the exhaust direction, which can use the power of the exhaust to prolong the adhesion time of condensate on the tube wall and improve the heat exchange effect.

[0025] (3) The indoor exhaust air sweeps across the heat exchange copper tubes, accelerating the evaporation of condensate. Utilizing the low-temperature characteristics and heat absorption properties of condensate, the fresh air inside the copper tubes is cooled. The indoor exhaust air inside the enclosure blows onto the surface of the heat exchange tubes, further accelerating the evaporation of condensate and thus improving the utilization rate of residual cooling.

[0026] (4) Unevaporated condensate accumulates at the bottom, wetting the wet membrane filter;

[0027] (5) When the indoor humidity sensor indicates that the indoor humidity is too low and humidification is needed, the controller energizes the electromagnet, causing the wet membrane filter to move upward and humidify the fresh air about to enter the room. The process continues until the indoor humidity reaches the standard, at which point the electromagnet is de-energized and the wet membrane filter returns to its original position.

[0028] It should be understood that the above summary and the following detailed description of the invention are exemplary and explanatory, and are intended to provide further explanation of the invention as claimed. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of one embodiment of the present invention.

[0030] Figure 2 for Figure 1A partially enlarged schematic diagram.

[0031] Figure 3 for Figure 2 AA sectional view.

[0032] Figure 4 This is a schematic diagram of the working state of one embodiment of the present invention. Detailed Implementation

[0033] To facilitate understanding by those skilled in the art, the structure of the present invention will now be described in further detail with reference to the accompanying drawings:

[0034] refer to Figure 1 A fresh air heat exchange device for utilizing condensate waste cooling includes:

[0035] Condensate pipe 2 is connected to the condensate drain outlet of the outdoor unit;

[0036] In this embodiment, the condensate pipe 2 is connected to the condensate drain outlet of the outdoor unit to receive the condensate generated during the operation of the outdoor unit.

[0037] The heat exchange tube 3 has one end for connecting to outdoor fresh air and the other end for outputting the outdoor fresh air into the room. The heat exchange tube 3 has a longitudinally encircling structure. The outlet of the condensate pipe 2 is arranged on the upper side of each top of the heat exchange tube 2, so that the condensate flows from the condensate pipe to each top of the heat exchange tube 3 and then flows downward along the heat exchange tube 3.

[0038] The heat exchange tube 3 is the core improvement of this embodiment. In this embodiment, condensate generated by the outdoor unit is collected via the condensate pipe 2, and then discharged to the top of the heat exchange tube 3 through the condensate pipe 2. The heat exchange tube 3 is used to transport outdoor fresh air; that is, outdoor fresh air flows within the heat exchange tube 3 to enter the room, and the outdoor fresh air does not directly contact the condensate. Direct contact between outdoor fresh air and condensate results in short contact time and simple contact between the two, leading to short heat exchange time and low efficiency. This embodiment extends the flow path of outdoor fresh air through the heat exchange tube 3, thereby enabling sufficient heat exchange between the condensate and the heat exchange tube 3.

[0039] The housing 1 is used to house the heat exchange tube 3. The housing 1 is provided with an indoor exhaust inlet 101 and an indoor exhaust outlet 102. The indoor exhaust inlet 101 is connected to the indoor exhaust air, so that the indoor exhaust air enters the housing 1 from the indoor exhaust inlet 101, exchanges heat with the heat exchange tube 3 and condensate, and is then discharged to the outside from the indoor exhaust outlet 102.

[0040] In this embodiment, the housing 1 houses the heat exchange tube 3 within a sealed space. Indoor exhaust air enters through the indoor exhaust inlet 101, comes into full contact with the heat exchange tube 3 inside the housing 1, and then exits through the indoor exhaust outlet 102. The advantages of this are: 1. The temperature of the indoor exhaust air is lower than the temperature of the outdoor fresh air, allowing for the recovery and utilization of some of the residual cooling in the indoor exhaust air; 2. When condensate flows through the heat exchange tube 3, it can directly exchange heat with the outdoor fresh air inside the tube, utilizing the residual cooling of the condensate. Furthermore, as the condensate flows on the surface of the heat exchange tube 3, the indoor exhaust air inside the housing 1 blows towards the surface of the heat exchange tube 3, accelerating the evaporation of the condensate and further improving the utilization rate of residual cooling.

[0041] Furthermore, the indoor exhaust inlet 101 and the indoor exhaust outlet 102 are diagonally arranged on the housing 1 to extend the circulation path of the indoor exhaust and improve the heat exchange efficiency between the indoor exhaust and the heat exchange tube and condensate.

[0042] like Figure 1 As shown, the indoor exhaust inlet 101 is located at the lower right corner of the housing 1, and the indoor exhaust outlet 102 is located at the upper left corner of the housing 1. By positioning the two outlets, the flow path of the indoor exhaust air within the housing 1 is diagonally upward, which extends the airflow path. Furthermore, the diagonally upward flow path slows down the speed at which condensate flows from the top to the bottom of the heat exchange tube 3, increasing the heat exchange time and further increasing the evaporation time of the condensate, thereby significantly improving the heat exchange efficiency.

[0043] Furthermore, the heat exchange tube 3 has corrugations on its outer surface, and the inclination angle of the corrugations is opposite to the flow path of the indoor exhaust air.

[0044] The corrugations increase the heat exchange area of ​​the heat exchange tube 3. Furthermore, the angle of the corrugations can be opposite to the flow path of the indoor exhaust air. The indoor exhaust air path is the direction of the line connecting the indoor exhaust air inlet 101 and the indoor exhaust air outlet 102. When condensate flows downwards on the outer wall of the heat exchange tube 3, the corrugations can cause the condensate to flow downwards at a certain angle. In this embodiment, the angle of the corrugations is opposite to or the same as the flow path of the indoor exhaust air; the angle of the corrugations is obliquely downwards to the right, while the flow path of the indoor exhaust air is obliquely upwards to the left. The condensate flows downwards to the right, and the indoor exhaust air blows upwards to the left, making the two flow in opposite directions. This allows the condensate to adhere to the outer surface of the corrugations for as long as possible, extending the heat exchange time for the air inside the heat exchange tube.

[0045] Furthermore, the outlet of the condensate pipe 2 is connected to the top of the heat exchange pipe 3 by a wet film 4, so that after the condensate is discharged, it is led to the top of the heat exchange pipe 3 through the wet film 4 and forms a water film on the outer wall of the heat exchange pipe 3.

[0046] The wet film 4 gently guides the condensate to the heat exchange tube 3, thus forming a water film on the surface of the heat exchange tube 3. The water film can more evenly and thinly cover the corrugated surface of the heat exchange tube 3, and then slowly flows downwards along the surface of the heat exchange tube 3 under the influence of gravity. The technical effect is that it increases the contact area between the condensate and the corrugations, preventing the condensate from accumulating and flowing downwards.

[0047] Furthermore, the corrugation inclination of the heat exchange tube is defined as i, tan(i) = 0.75~0.85; the tube diameter of the heat exchange tube is 250~350mm; and the air velocity of the indoor exhaust is configured as 4.5~5.5m / s.

[0048] In this embodiment, the tilt angle of the corrugations is approximately between 37° and 41°. A single-variable experiment on the tilt angle was conducted under the following conditions: heat exchange tube length 1m, indoor exhaust air velocity set to 5m / s, heat exchange tube diameter 300mm, indoor exhaust air temperature 26℃, outdoor fresh air temperature 30℃, and the tilt angle of the corrugations opposite to the flow path of the indoor exhaust air. The results are shown in Table 1.

[0049] Table 1. Experimental Results of Uniformity of Corrugation Inclination Angle

[0050]

[0051] Table 1 shows that the larger the inclination angle of the corrugated pipe, the lower the temperature of the condensate when it reaches the bottom of the heat exchange tube, indicating poor heat exchange efficiency and low heat exchange efficiency between the condensate on the corrugated pipe and the outdoor fresh air inside the heat exchange tube. Furthermore, when the tan(i) corresponding to the corrugation angle is between 0.75 and 0.8, the temperature change of the condensate when it reaches the bottom of the heat exchange tube is slow, indicating that a tan(i) between 0.75 and 0.8 corresponding to the corrugation angle is preferred.

[0052] Then, a single-variable experiment was conducted under the following conditions: heat exchange tube diameter 250–300 mm; heat exchange tube length 1 m; indoor exhaust air velocity set to 5 m / s; tan(i) = 0.8; indoor exhaust air temperature 26℃; outdoor fresh air temperature 30℃; and the corrugation angle opposite to the indoor exhaust air flow path. The results are shown in Table 2.

[0053] Table 2 Results of the experiment on the uniformity of heat exchanger tube diameter

[0054]

[0055] Table 2 illustrates that within the heat exchanger tube diameter range of 250–300 mm, smaller diameters result in faster airflow velocity within the tubes, shortening the heat exchange time and thus reducing heat exchange efficiency. However, within the 300–350 mm range, larger diameters lead to a decrease in the surface area / cross-sectional area of ​​the heat exchanger tubes, further reducing heat exchange efficiency. 300 mm is considered the optimal heat exchanger tube diameter.

[0056] Then, a single-variable experiment was conducted under the following conditions: indoor exhaust air velocity set to 4.5–5.5 m / s; heat exchange tube length 1 m; tan(i) = 0.8; heat exchange tube diameter 300 mm; indoor exhaust air temperature 26 °C; outdoor fresh air temperature 30 °C; and the corrugation angle was opposite to the indoor exhaust air flow path. The results are shown in Table 3.

[0057] Table 3 Indoor exhaust air velocity uniformity experiment

[0058]

[0059] Table 3 shows that within the indoor exhaust air velocity range of 4.5–5 m / s, higher velocities lead to a rapid increase in heat exchange efficiency. However, within the 5–5.5 m / s range, higher velocities do not significantly improve heat exchange efficiency. This is because condensate naturally flows downwards along the outer wall of the heat exchange tubes under gravity. In the 4.5–5 m / s range, the indoor exhaust air velocity slows down the downward flow of condensate, prolonging the heat exchange process. However, in the 5–5.5 m / s range, the indoor exhaust air velocity obstructs the downward flow of condensate. As a result, the condensate remains near the bottom even after most of its residual cooling has been exchanged for heat. Therefore, an indoor exhaust air velocity of around 5 m / s is optimal.

[0060] Finally, based on three variable factors—tan(i) = 0.75–0.85, the diameter of the heat exchange tube being 250–350 mm, and the air velocity of the indoor exhaust being configured to be 4.5–5.5 m / s—an orthogonal experiment was conducted, and it was determined that the heat exchange efficiency was optimal when tan(i) = 0.8, the diameter of the heat exchange tube being 300 mm, and the air velocity of the indoor exhaust being configured to be 5 m / s.

[0061] Furthermore, the bottom of the housing 1 is inclined downwards at the end facing the heat exchange tube 3 that outputs the outdoor fresh air into the room, in order to collect condensate.

[0062] Furthermore, a wet membrane filter 502 is provided at the end of the heat exchange tube 3 that outputs the outdoor fresh air into the room. The wet membrane filter 502 is driven by a driving mechanism. The driving mechanism can drive the wet membrane filter 502 to contact the condensate at the bottom of the housing 1, and / or the driving mechanism can drive the wet membrane filter 502 to cover the end of the heat exchange tube 3 that outputs the outdoor fresh air into the room, and / or the driving mechanism can drive the wet membrane filter 502 to avoid the end of the heat exchange tube 3 that outputs the outdoor fresh air into the room.

[0063] Furthermore, it includes a humidity sensor 505 and a control system 504, wherein the humidity sensor 505 is used to acquire indoor humidity.

[0064] When the indoor humidity is lower than the first threshold, the control system 504 controls the drive mechanism to drive the wet membrane filter 502 to contact the condensate at the bottom of the box 1, and then drives the wet membrane filter 502 to cover the end of the heat exchange tube 3 that outputs the outdoor fresh air to the room.

[0065] When the indoor humidity is higher than the first threshold, the control system controls the drive mechanism to drive the wet membrane filter 502 to bypass the heat exchange tube 3 and output the outdoor fresh air into the room.

[0066] Furthermore, the driving mechanism includes an electromagnet 501 and a spring 503. The electromagnet 501 receives control from the control system 504 and can move upward. The wet membrane filter 502 is connected to the lower end of the electromagnet 501, thereby driving the wet membrane filter 502 to move upward. The spring 503 is connected to the lower end of the wet membrane filter 502, thereby pulling the wet membrane filter 502 downward after the electromagnet 501 is de-energized. After the wet membrane filter 502 moves upward, it covers the end of the heat exchange tube 3 that outputs the outdoor fresh air into the room. After the wet membrane filter 502 moves downward, it contacts the condensate at the bottom of the housing 1.

[0067] refer to Figure 2 Unevaporated condensate accumulates at the bottom, which moistens the wet membrane filter 502. When the indoor humidity sensor 505 indicates that the indoor humidity is too low and humidification is needed, the control system 504 energizes the electromagnet 501, causing the wet membrane filter 502 to move upward and humidify the incoming fresh air. Once the indoor humidity reaches the target level, the electromagnet is de-energized, the wet membrane filter 502 returns to its original position, and the opening 506 above the wet membrane filter 502 allows outdoor fresh air to directly enter the room.

[0068] An air conditioner comprising a fresh air heat exchange device for utilizing residual cooling of condensate as described in any one of the claims.

[0069] Experimental data

[0070] refer to Figure 4 The fresh air heat exchange device provided in this embodiment, used in conjunction with a total heat recovery fresh air unit, connects the fresh air processed by the total heat recovery fresh air unit to the device of this invention. The total heat recovery fresh air unit is a commercially available device suitable for indoor areas of 500m². 2 The office area was simulated and calculated, resulting in Table 4.

[0071] Table 4 Simulation Calculation Results

[0072]

[0073] Simulation data shows that the fresh air heat exchange device provided in this embodiment can process outdoor fresh air from 31.3℃ to 17.9℃, and the comprehensive recovery of cooling capacity can be increased from 7kW to 20.6kW, achieving energy savings of more than 40% for air conditioning.

[0074] It should be noted that any reference signs placed between parentheses in the claims should not be construed as limiting the claims. The word "comprising" does not exclude the presence of components or steps not listed in the claims. The word "a" or "an" preceding a component does not exclude the presence of a plurality of such components. The invention can be implemented by means of hardware comprising several different components and by means of a suitably programmed computer. In a unit claim enumerating several means, several of these means may be embodied by the same item of hardware. The use of the words first, second, and third, etc., does not indicate any order. These words can be interpreted as names.

[0075] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0076] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0077] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms should not be construed as necessarily referring to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

Claims

1. A fresh air heat exchange device for condensate surplus heat utilization, characterized in that: The application relates to a condenser for air conditioning, comprising: a condensate pipe connected to a condensate discharge port of an outdoor unit; a heat exchange pipe, one end of the heat exchange pipe being used for connecting to outdoor fresh air, the other end of the heat exchange pipe being used for outputting the outdoor fresh air to the indoor, the heat exchange pipe being in a longitudinal surrounding structure, a water outlet of the condensate pipe being arranged on the upper side of each top end of the heat exchange pipe, so that the condensate discharged from the condensate pipe flows to each top end of the heat exchange pipe and then flows downward along the heat exchange pipe, the heat exchange pipe being provided with corrugations on the outer surface, the inclination angle of the corrugations being opposite to the flow path of indoor exhaust air, the water outlet of the condensate pipe and the top end of the heat exchange pipe being connected through a wet film, so that the condensate discharged through the wet film is led to the top end of the heat exchange pipe and forms a water film on the outer wall of the heat exchange pipe, the inclination of the corrugations of the heat exchange pipe being defined as i, tan (i) = 0.75-0.85, the pipe diameter of the heat exchange pipe being 250-350 mm, and the wind speed of the indoor exhaust air being configured to be 4.5-5.5 m / s; a box body used for containing the heat exchange pipe, the box body being provided with an indoor exhaust air inlet and an indoor exhaust air outlet, the indoor exhaust air inlet being connected to indoor exhaust air, so that the indoor exhaust air enters the box body from the indoor exhaust air inlet, exchanges heat with the heat exchange pipe and the condensate, and is then discharged to the outdoor from the indoor exhaust air outlet, the indoor exhaust air inlet and the indoor exhaust air outlet being diagonally arranged on the box body, so as to prolong the flow path of the indoor exhaust air and improve the heat exchange efficiency of the indoor exhaust air with the heat exchange pipe and the condensate.

2. The fresh air heat exchange device of claim 1, wherein: The bottom of the box body is downwardly inclined towards the end of the heat exchange pipe outputting the outdoor fresh air to the indoor, so as to collect the condensate.

3. The fresh air heat exchange device of claim 2, wherein: The box body is provided with a wet film filter screen at the end of the heat exchange pipe outputting the outdoor fresh air to the indoor, the wet film filter screen being driven by a driving mechanism, the driving mechanism being capable of driving the wet film filter screen to contact the condensate on the bottom of the box body, and / or the driving mechanism being capable of driving the wet film filter screen to cover the end of the heat exchange pipe outputting the outdoor fresh air to the indoor, and / or the driving mechanism being capable of driving the wet film filter screen to avoid the end of the heat exchange pipe outputting the outdoor fresh air to the indoor.

4. The fresh air heat exchange device of claim 3, wherein: The application further comprises a humidity sensor and a control system, the humidity sensor being used for acquiring indoor humidity, when the indoor humidity is lower than a first threshold value, the control system controls the driving mechanism to drive the wet film filter screen to contact the condensate on the bottom of the box body, and then drives the wet film filter screen to cover the end of the heat exchange pipe outputting the outdoor fresh air to the indoor; when the indoor humidity is higher than the first threshold value, the control system controls the driving mechanism to drive the wet film filter screen to avoid the end of the heat exchange pipe outputting the outdoor fresh air to the indoor.

5. The fresh air heat exchange device of claim 4, wherein: The driving mechanism comprises an electromagnet and a spring, the electromagnet receives the control of the control system and can move upward, the wet membrane filter screen is connected to the lower end of the electromagnet, so that the wet membrane filter screen can be driven to move upward, the spring is connected to the lower end of the wet membrane filter screen, so that the wet membrane filter screen can be pulled to move downward after the electromagnet is powered off, the wet membrane filter screen covers the end of the heat exchange pipe outputting outdoor fresh air to the room after moving upward, and the wet membrane filter screen contacts the condensed water at the bottom of the box after moving downward.

6. An air conditioner characterized by comprising: The fresh air heat exchange device comprises a box body, a heat exchange pipe and a wet membrane filter screen.

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