Self-preheating freeze-proof fresh air handling unit

Abstract

The application discloses a self-preheating freeze-proof fresh air unit and relates to the field of fresh air systems. The unit comprises a shell, the two sides of the shell are respectively provided with an air inlet and an air outlet, a partition plate is arranged between the air inlet and the air outlet in the shell, an air inlet compartment is formed on the side of the partition plate close to the air inlet in the shell, an air supply compartment is formed on the side of the partition plate close to the air outlet in the shell, and a ventilation opening is formed in the partition plate; a cross-flow heat exchanger is arranged in the air inlet compartment, the cross-flow heat exchanger comprises an air inlet channel and an air supply channel, the air inlet channel and the air supply channel are arranged in a cross manner, one end of the air inlet channel is communicated with the air inlet, one end of the air supply channel is communicated with the ventilation opening, and a surface air cooler is arranged in the air inlet compartment. The application has the effect of reducing the situation that low-temperature air enters the shell and causes the freezing and cracking of liquid medium in the surface air cooler and / or the heat exchanger.

Description

Technical Field

[0001] This application relates to the field of fresh air systems, and in particular to a self-preheating and antifreeze fresh air unit. Background Technology

[0002] A fresh air handling unit is an air conditioning device that provides fresh air. It works by drawing in fresh outdoor air, processing it through dust removal, dehumidification (or humidification), and heating (or cooling), and then sending it indoors via a fan, replacing the existing indoor air as it enters the space.

[0003] In related technologies, a fresh air handling unit includes a housing with an air inlet and an air outlet on opposite sides. A pre-filter is fixedly installed at the air inlet, covering the air inlet. A heat exchanger is installed inside the housing near the air inlet, and a centrifugal fan is installed on the housing near the air outlet, with the exhaust port of the centrifugal fan connected to the air outlet of the housing. The heat exchanger typically uses a liquid medium to exchange heat with the air.

[0004] Regarding the aforementioned technologies, the high-temperature medium introduced into the heat exchanger can transfer heat to the air inside the enclosure, raising the air temperature, and then be delivered into the room by a centrifugal fan. However, in some areas of northern my country, temperatures can reach -20°C in cold weather. At this temperature, when cold air enters the enclosure, it can easily freeze the liquid medium inside the heat exchanger, making it difficult for the fresh air unit to operate normally, thus requiring urgent improvement. Summary of the Invention

[0005] In order to improve the problem in related technologies that low-temperature air entering the box can easily freeze the liquid medium in the heat exchanger, making it difficult for the fresh air unit to work properly, this application provides a self-preheating and antifreeze fresh air unit.

[0006] This application provides a self-preheating and antifreeze fresh air handling unit, which adopts the following technical solution:

[0007] A self-preheating and antifreeze fresh air unit includes a housing, with an air inlet and an air outlet respectively provided on both sides of the housing. A baffle plate is provided inside the housing between the air inlet and the air outlet. An air inlet compartment is formed inside the housing on the side of the baffle plate near the air inlet, and an air supply compartment is formed inside the housing on the side of the baffle plate near the air outlet. Ventilation openings are provided on the baffle plate.

[0008] A cross-flow heat exchanger is installed in the air inlet compartment. The cross-flow heat exchanger includes an air inlet channel and an air supply channel, which are arranged crosswise. One end of the air inlet channel is connected to the air inlet, and one end of the air supply channel is connected to the vent. A surface cooler is installed in the air inlet compartment.

[0009] By adopting the above technical solution, in cold weather, when the fresh air unit starts, hot water can be introduced into the surface cooler, which will heat the air in the air intake compartment. As air flows within the casing, fresh air from outside enters the air intake duct through the air inlet, while the warmer air in the air intake compartment enters the air supply compartment through the air supply duct. During this process, the warmer air and the fresh air flowing through the air intake duct exchange heat, raising the temperature of the fresh air. Subsequently, the fresh air entering the air intake compartment is heated by the surface cooler and enters the air supply compartment through the air supply duct, finally being delivered into the room through the air outlet. In this way, the hot air flowing through the air supply duct preheats the air flowing through the air intake duct, helping to reduce the possibility of low-temperature air entering the casing and causing the liquid medium in the surface cooler and / or heat exchanger to freeze and crack, and helping to ensure the normal operation of the fresh air unit.

[0010] Preferably, the surface cooler is located on the side of the air supply channel away from the vent.

[0011] By adopting the above technical solution, most of the air will be heated by the surface cooler when it enters the air supply channel, which helps to improve the overall heating of the air entering the air supply channel by the surface cooler and helps to improve the preheating efficiency of the air passing through the air intake channel.

[0012] Preferably, the air inlet compartment is provided with a partition plate, which divides the air inlet compartment into an air intake side chamber and a preheating side chamber. The air intake side chamber is connected to the air inlet. The partition plate has a connecting port, and the air inlet channel is connected to the connecting port of the air inlet.

[0013] By adopting the above technical solution, the heat emitted by the surface cooler can raise the temperature of the induced draft side chamber. The fresh air entering the induced draft side chamber will be preheated in advance, thereby further reducing the occurrence of low temperature air entering the shell and causing the liquid medium in the surface cooler and / or heat exchanger to freeze and crack.

[0014] Preferably, the surface cooler is arranged close to the partition plate.

[0015] By adopting the above technical solutions, it is helpful to improve the heating efficiency of the surface cooler on the induced draft side chamber.

[0016] Preferably, the air inlet compartment is provided with an air guide plate for guiding the air flowing out of the air inlet channel to one side of the surface cooler.

[0017] By adopting the above technical solution, the air guide plate directs the fresh air to the surface cooler, which helps to improve the overall heating of the air entering the air supply channel by the surface cooler and helps to improve the preheating efficiency of the air passing through the air intake channel.

[0018] Preferably, a first heat exchanger is provided in the air supply compartment, and a compressor and a second heat exchanger are provided on the outside of the shell. One side of the first heat exchanger is connected to the compressor, and the other side of the first heat exchanger is connected to one side of the second heat exchanger via a medium pipe. The other side of the second heat exchanger is connected to the compressor, and a first expansion valve is provided on the medium pipe.

[0019] By adopting the above technical solution, the first heat exchanger, the compressor, the second heat exchanger, and the first expansion valve constitute a refrigeration and heating system.

[0020] In hot weather, the surface cooler can be shut off, or chilled water can be introduced into the surface cooler to pre-cool the fresh air. Simultaneously, the compressor draws refrigerant from the first heat exchanger and compresses it into a high-pressure, high-temperature gaseous state. Then, the compressor sends this high-temperature, high-pressure gaseous refrigerant into the second heat exchanger to exchange heat with the outside air, transforming the refrigerant into a medium-temperature, high-pressure liquid state and releasing heat. Subsequently, the medium-temperature, high-pressure liquid refrigerant is throttled by the first expansion valve, transforming into a low-temperature, low-pressure liquid state. Finally, the low-temperature, low-pressure liquid refrigerant enters the first heat exchanger and exchanges heat with the fresh air in the supply air compartment. At this point, the refrigerant changes from liquid to gaseous, absorbing heat from the fresh air and lowering its temperature within the supply air compartment, thus achieving the cooling function of the fresh air handling unit.

[0021] In cold weather, the surface cooler is turned on, supplying hot water to preheat the fresh air. Simultaneously, the compressor draws refrigerant from the second heat exchanger and compresses it into a high-pressure, high-temperature gaseous state. Then, the compressor sends this high-temperature, high-pressure gaseous refrigerant into the first heat exchanger, where it exchanges heat with the fresh air in the supply air compartment. At this point, the refrigerant changes from a gaseous state to a liquid state, releasing heat and raising the temperature of the fresh air in the supply air compartment, transforming into a medium-temperature, high-pressure liquid state. Subsequently, the medium-temperature, high-pressure liquid refrigerant is throttled through the first expansion valve, transforming into a low-temperature, low-pressure liquid state. Finally, the low-temperature, low-pressure liquid refrigerant enters the second heat exchanger and exchanges heat with the outside air, changing from a liquid state to a gaseous state and absorbing heat from the outside air. This achieves the heating function of the fresh air handling unit.

[0022] In a suitable temperature environment, people indoors can activate the surface cooler and / or the cooling and heating system as needed to cool and heat the room.

[0023] It should be noted that high temperature and high pressure, medium temperature and high pressure, and low temperature and low pressure are relative states of the refrigerant in different parts of the refrigeration and heating system.

[0024] Preferably, the first heat exchanger is located between the vent and the air outlet, and a third heat exchanger is provided between the first heat exchanger and the air outlet. The first expansion valve is located in the middle of the medium pipe. One side of the third heat exchanger is connected to the side of the medium pipe near the second heat exchanger. One side of the third heat exchanger is connected to a reversing pipe. The end of the reversing pipe away from the third heat exchanger is connected to the side of the medium pipe near the first heat exchanger, and a second expansion valve is provided on the reversing pipe.

[0025] By adopting the above technical solution, in cold weather, the first expansion valve is opened and the second expansion valve is closed. After the medium-temperature high-pressure liquid refrigerant is throttled by the first expansion valve, it can directly enter the second heat exchanger, and the third heat exchanger does not participate in the heating work.

[0026] In hot weather, the first expansion valve is closed and the second expansion valve is opened. At this time, the medium-temperature high-pressure liquid formed after heat exchange in the second heat exchanger will pass through the third heat exchanger. After the fresh air passes through the first heat exchanger, it will be cooled and dehumidified, and the temperature will be low. When the fresh air passes through the third heat exchanger, the cooled and dehumidified fresh air will be preheated, which helps to improve the comfort of the people indoors after the fresh air is supplied to the room.

[0027] Preferably, the air inlet channel is vertical, a pull rod is vertically installed on the housing, the pull rod passes through the air inlet channel, a filter screen is fixed on the pull rod, an avoidance opening is provided on the lower side of the housing, the avoidance opening is located directly below the filter screen, and a sealing plate for closing the avoidance opening is also provided on the housing.

[0028] By adopting the above technical solution, the filter screen filters the dust in the air, slowing down the speed at which dust adheres to the air intake channel, which helps to extend the working time of the cross-flow heat exchanger to maintain good heat exchange efficiency.

[0029] Furthermore, when there is a lot of dust on the filter screen, the staff can remove the sealing plate and pull the filter screen out of the housing using the pull rod to clean the filter screen and facilitate the cleaning operation.

[0030] It should be noted that when there is a lot of dust adhering to the side wall of the air inlet channel, the heat exchange efficiency of the cross-flow heat exchanger will decrease.

[0031] Preferably, a cutting frame is fixed to the periphery of the filter screen, and the periphery of the cutting frame abuts against the side wall of the air inlet channel and slides in cooperation with the air inlet channel.

[0032] By adopting the above technical solution, when the filter screen is pulled down by the pull rod, the cutting frame slides in the air inlet channel and removes the dust from the side wall of the air inlet channel, thereby cleaning the side wall of the air inlet channel and helping to ensure the normal heat exchange operation of the cross-flow heat exchanger.

[0033] Preferably, the sealing plate is detachably fixed to the lower side of the pull rod.

[0034] By adopting the above technical solution, in actual application, when the sealing plate is pulled down, the pull rod, filter screen and cutting frame will move synchronously, and the dust peeled off from the side wall of the air inlet channel by the cutting frame will be received and collected by the sealing plate, reducing the occurrence of dust falling around when the cutting frame peels off from the air inlet channel.

[0035] Furthermore, the sealing plate can be removed from the pull rod to facilitate cleaning of the sealing plate.

[0036] Preferably, a tension spring is fixed between the upper end of the pull rod and the upper side wall of the housing.

[0037] By adopting the above technical solution, when cleaning the filter screen, pulling the lever will stretch the tension spring; after the filter screen is cleaned, the tension spring can pull the lever and the filter screen back to their original positions, thus facilitating the loading of the filter screen.

[0038] Preferably, the filter screen and the pull rod are detachably fixed.

[0039] By adopting the above technical solution, the filter screen can be removed from the pull rod after pulling it down, which facilitates the cleaning of the filter screen.

[0040] In summary, this application includes at least one of the following beneficial technical effects:

[0041] 1. Preheating the air flowing through the air intake duct with hot air flowing through the air supply duct helps reduce the occurrence of low-temperature air entering the casing and causing the liquid medium in the surface cooler and / or heat exchanger to freeze and crack, and helps ensure the normal operation of the fresh air unit.

[0042] 2. By using a filter screen installed on the pull rod and a cutting frame around the filter screen, it is possible to reduce the accumulation of dust on the side wall of the air inlet channel and help ensure the normal heat exchange operation of the cross-flow heat exchanger. Attached Figure Description

[0043] Figure 1 This embodiment mainly illustrates the system diagram of the self-preheating and antifreeze fresh air handling unit;

[0044] Figure 2 This is an isometric schematic diagram illustrating the overall structure of the self-preheating and antifreeze fresh air handling unit, which is the main feature of this embodiment.

[0045] Figure 3 This is a schematic diagram illustrating the structure of the cross-flow heat exchanger, which is the main feature of this embodiment.

[0046] Figure 4 This is a partial schematic diagram illustrating the structure of the pull rod, tension spring, and filter screen in this embodiment.

[0047] Figure 5 This is a partial schematic diagram illustrating the clearance and sealing plate structure in this embodiment;

[0048] Figure 6 This is a schematic diagram illustrating the filter screen and cutting frame structure, which are the main features of this embodiment.

[0049] Reference numerals: 1. Shell; 11. Air inlet; 12. Air outlet; 13. Baffle plate; 14. Air inlet compartment; 141. Partition plate; 1411. Connecting port; 142. Exhaust side compartment; 143. Preheating side compartment; 15. Air supply compartment; 16. Ventilation port; 17. Circumvention port; 2. Surface cooler; 3. First heat exchanger; 31. Compressor; 32. Second heat exchanger; 33. Medium pipe; 331. First expansion valve; 34. Third heat exchanger; 35. Reversing pipe; 351. Second expansion valve; 4. Centrifugal fan; 5. Cross-flow heat exchanger; 51. Air inlet channel; 52. Air supply channel; 53. Air guide plate; 6. Tie rod; 61. Tension spring; 62. Locking nut; 63. Fastening nut; 7. Filter screen; 71. Cutting frame; 8. Sealing plate. Detailed Implementation

[0050] The following is in conjunction with the appendix Figure 1-6 This application will be described in further detail.

[0051] This application discloses a self-preheating and antifreeze fresh air handling unit.

[0052] Example 1:

[0053] Reference Figure 1 and Figure 2 The self-preheating and antifreeze fresh air unit includes a casing 1, which is horizontal in its length direction. An air inlet 11 and an air outlet 12 are respectively provided on both sides of the casing 1 along its length. A baffle plate 13 is fixed in the middle of the casing 1. The baffle plate 13 is vertically arranged, and its periphery abuts against the upper and lower side walls and the two side walls in the width direction of the casing 1. An air inlet chamber 14 is formed inside the casing 1 on the side of the baffle plate 13 near the air inlet 11, and an air supply chamber 15 is formed inside the casing 1 on the side of the baffle plate 13 near the air outlet 12. A ventilation opening 16 is provided in the middle of the baffle plate 13 (see...). Figure 3 A surface cooler 2 is installed in the air inlet compartment 14, which is located between the air inlet 11 and the vent 16. A first heat exchanger 3 is installed in the air supply compartment 15, which is located between the vent 16 and the air outlet 12. A centrifugal fan 4 is installed between the first heat exchanger 3 and the air outlet 12, and the exhaust port of the centrifugal fan 4 faces the air outlet 12.

[0054] In cold weather, the centrifugal fan 4 operates, introducing hot water into the surface cooler 2. Fresh air enters the air inlet compartment 14 through the air inlet 11 and is preheated by the surface cooler 2. Then, the fresh air enters the air supply compartment 15 through the vent 16 and is heated by the first heat exchanger 3. Finally, under the action of the centrifugal fan 4, the fresh air is sent into the room through the air outlet 12.

[0055] Specifically, see Figure 1 and Figure 3 A partition plate 141 is fixed inside the air inlet compartment 14. The partition plate 141 is horizontal in the width direction. The two sides of the partition plate 141 in the width direction abut against the inner walls of the two sides of the housing 1 in the width direction, respectively. The two sides of the partition plate 141 in the length direction of the housing 1 abut against the side wall of the housing 1 on the side of the air inlet 11 and the baffle plate 13, respectively. The side of the partition plate 141 near the air inlet 11 is located below the air inlet 11, and the side of the partition plate 141 near the baffle plate 13 is located above the vent 16. Furthermore, the partition plate 141 divides the air inlet compartment 14 into an exhaust side compartment 142 and a preheating side compartment 143. The exhaust side compartment 142 is located above the partition plate 141 and communicates with the air inlet 11, while the preheating side compartment 143 is located below the partition plate 141 and communicates with the vent 16.

[0056] A cross-flow heat exchanger 5 is fixed inside the preheating side chamber 143. A connecting port 1411 is provided on the side of the partition plate 141 near the vent 16. The cross-flow heat exchanger 5 includes an air inlet channel 51 and an air outlet channel 52. The air inlet channel 51 is vertical, and its upper end connects to the connecting port 1411. The air outlet channel 52 runs along the length of the shell 1, and its end near the baffle plate 13 connects to the vent 16. A surface cooler 2 is located on the side of the cross-flow heat exchanger 5 away from the baffle plate 13, and is positioned close to the partition plate 141. The end of the air outlet channel 52 away from the vent 16 faces the surface cooler 2. Simultaneously, a guide vane 53 is fixed to the lower side of the cross-flow heat exchanger 5 near the surface cooler 2. The guide vane 53 is horizontal and points towards the surface cooler 2. In other embodiments, the cross-flow heat exchanger can be any of a sensible heat exchanger, a total heat exchanger, or a plate-fin sensible heat exchanger.

[0057] In cold weather, when the fresh air unit is operating, the surface cooler 2 heats the air in the preheating side chamber 143. Then, under the action of the centrifugal fan 4, the air in the preheating side chamber 143 flows into the air supply compartment 15 through the air supply duct 52. Fresh air enters the induced draft side chamber 142 through the air inlet 11 and is preheated, and then flows into the preheating side chamber 143 through the air inlet duct 51. When the fresh air flows through the air inlet duct 51, it exchanges heat with the hot air flowing through the air supply duct 52, thereby further preheating the fresh air and reducing the possibility of low-temperature air entering the casing 1 and causing the liquid medium in the surface cooler 2 and / or heat exchanger to freeze and crack.

[0058] See Figure 1 A compressor 31 and a second heat exchanger 32 are disposed on the outer side of the casing 1. One side of the first heat exchanger 3 is connected to the compressor 31, and the other side of the first heat exchanger 3 is connected to one side of the second heat exchanger 32 via a medium pipe 33. The other side of the second heat exchanger 32 is connected to the compressor 31, and a first expansion valve 331 is disposed in the middle of the medium pipe 33. The first heat exchanger 3 is located between the vent 16 and the air outlet 12. A third heat exchanger 34 is disposed between the first heat exchanger 3 and the air outlet 12. One side of the third heat exchanger 34 is connected to the side of the medium pipe 33 near the second heat exchanger 32, and a reversing pipe 35 is connected to one side of the third heat exchanger 34. The end of the reversing pipe 35 away from the third heat exchanger 34 is connected to the side of the medium pipe 33 near the first heat exchanger 3, and a second expansion valve 351 is disposed on the reversing pipe 35. In this embodiment, both the first expansion valve 331 and the second expansion valve 351 are electronic expansion valves.

[0059] In cold weather, the first expansion valve 331 is opened and the second expansion valve 351 is closed. The compressor 31, the first heat exchanger 3, the first expansion valve 331, and the second heat exchanger 32 work together, with the first heat exchanger 3 exchanging heat with the fresh air to raise its temperature. In hot weather, the first expansion valve 331 is closed and then opened. The compressor 31, the second heat exchanger 32, the third heat exchanger 34, the second expansion valve 351, and the first heat exchanger 3 work together, with the first heat exchanger 3 exchanging heat with the fresh air to lower its temperature.

[0060] The implementation principle of a self-preheating and antifreeze fresh air unit according to an embodiment of this application is as follows: In cold weather, hot water is supplied to the surface cooler 2, which heats the air in the preheating side chamber 143. Then, under the action of the centrifugal fan 4, the air in the preheating side chamber 143 flows into the air supply compartment 15 through the air supply duct 52. Fresh air enters the induced draft side chamber 142 through the air inlet 11 and flows into the preheating side chamber 143 through the air inlet duct 51. The fresh air is preheated in the induced draft side chamber 142 and the air inlet duct 51. After the fresh air enters the air supply compartment 15, it is heated by the first heat exchanger 3, and the heated fresh air is sent into the room by the centrifugal fan 4.

[0061] Example 2:

[0062] Reference Figure 4 and Figure 5 The difference between this embodiment and Embodiment 1 is that:

[0063] A vertical pull rod 6 is installed inside the housing 1, passing through the air inlet channel 51. A tension spring 61 is fixed between the upper end of the pull rod 6 and the upper inner wall of the housing 1. A filter screen 7 is installed on the upper side of the air inlet channel 51 (see...). Figure 6The filter screen 7 is plate-shaped with an array of mesh holes and is horizontal. A pull rod 6 passes through the middle of the filter screen 7, and locking nuts 62 are threaded onto the upper and lower sides of the pull rod 6, clamping the filter screen 7. A cutting frame 71 is arranged around the periphery of the filter screen 7. The inner side of the cutting frame 71 is fixed to the periphery of the filter screen 7, and the periphery of the cutting frame 71 abuts against the side wall of the air inlet channel 51 and slides vertically into the air inlet channel 51.

[0064] The housing 1 has a clearance opening 17 directly below the air inlet channel 51. A sealing plate 8 is provided on the lower side of the clearance opening 17. The sealing plate 8 is horizontal and closes the clearance opening 17. The upper edge of the sealing plate 8 abuts against the lower side of the housing 1. The lower end of the pull rod 6 passes through the sealing plate 8, and fastening nuts 63 are threadedly connected to both the upper and lower sides of the pull rod 6 on the sealing plate 8. The two fastening nuts 63 clamp the sealing plate 8. Furthermore, the pull rod 6, tension spring 61, filter screen 7, cutting frame 71, clearance opening 17, and sealing plate 8 all correspond one-to-one with the air inlet channel 51, and the locking nut 62 and fastening nut 63 are both provided corresponding to the pull rod 6.

[0065] When cleaning of the filter 7 and the inner wall of the air inlet channel 51 is required, the pull rod 6 and the sealing plate 8 can be pulled down. The filter 7 and the cutting frame 71 will move synchronously. The cutting frame 71 slides inside the air inlet channel 51, removing dust from the side wall of the air inlet channel 51. The dust removed from the side wall of the air inlet channel 51 by the cutting frame 71 will be received and collected by the sealing plate 8. As the pull rod 6 is pulled down continuously, the filter 7 and the cutting frame 71 can be pulled out of the housing 1 through the clearance opening 17. At this time, the fastening nut 63 and the locking nut 62 can be unscrewed in sequence, and the sealing plate 8 and the filter 7 can be removed for cleaning.

[0066] After cleaning the sealing plate 8 and the filter screen 7, pull down the pull rod 6 and fix the filter screen 7 to the upper side of the pull rod 6 with the locking nut 62, and fix the sealing plate 8 to the lower side of the pull rod 6 with the fastening nut 63; then, release the pull rod 6, and under the pull of the tension spring 61, the filter screen 7 and the cutting frame 71 will enter the air inlet channel 51, and the sealing plate 8 will close the avoidance opening 17.

[0067] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A self-preheating and antifreeze fresh air handling unit, comprising a housing (1), wherein an air inlet (11) and an air outlet (12) are respectively provided on both sides of the housing (1), characterized in that: A baffle plate (13) is provided inside the housing (1) between the air inlet (11) and the air outlet (12). An air inlet compartment (14) is formed inside the housing (1) on the side of the baffle plate (13) near the air inlet (11). An air supply compartment (15) is formed inside the housing (1) on the side of the baffle plate (13) near the air outlet (12). A ventilation opening (16) is provided on the baffle plate (13). A cross-flow heat exchanger (5) is provided in the air inlet compartment (14). The cross-flow heat exchanger (5) includes an air inlet channel (51) and an air supply channel (52). The air inlet channel (51) and the air supply channel (52) are arranged in a cross manner. One end of the air inlet channel (51) is connected to the air inlet (11), and one end of the air supply channel (52) is connected to the vent (16). A surface cooler (2) is provided in the air inlet compartment (14). The air inlet compartment (14) is provided with a partition plate (141), which divides the air inlet compartment (14) into an air intake side chamber (142) and a preheating side chamber (143). The air intake side chamber (142) is connected to the air inlet (11). The partition plate (141) has a connecting port (1411). The port of the air inlet channel (51) used to connect with the air inlet (11) is connected to the connecting port (1411). The surface cooler (2) is located in the preheating side chamber (143). The air inlet compartment (14) is provided with an air guide plate (53) for guiding the air flowing out of the air inlet channel (51) to one side of the surface cooler (2).

2. The self-preheating and antifreeze fresh air handling unit according to claim 1, characterized in that: The surface cooler (2) is located on the side of the air supply channel (52) away from the vent (16).

3. The self-preheating and antifreeze fresh air handling unit according to claim 1, characterized in that: The surface cooler (2) is positioned adjacent to the partition plate (141).

4. The self-preheating and antifreeze fresh air handling unit according to claim 1, characterized in that: The air supply compartment (15) is provided with a first heat exchanger (3), and the outer side of the shell (1) is provided with a compressor (31) and a second heat exchanger (32). One side of the first heat exchanger (3) is connected to the compressor (31), and the other side of the first heat exchanger (3) is connected to one side of the second heat exchanger (32) via a medium pipe (33). The other side of the second heat exchanger (32) is connected to the compressor (31), and a first expansion valve (331) is provided on the medium pipe (33).

5. A self-preheating and antifreeze fresh air handling unit according to claim 4, characterized in that: The first heat exchanger (3) is located between the vent (16) and the air outlet (12). A third heat exchanger (34) is provided between the first heat exchanger (3) and the air outlet (12). The first expansion valve (331) is located in the middle of the medium pipe (33). One side of the third heat exchanger (34) is connected to the side of the medium pipe (33) near the second heat exchanger (32). One side of the third heat exchanger (34) is connected to a reversing pipe (35). The end of the reversing pipe (35) away from the third heat exchanger (34) is connected to the side of the medium pipe (33) near the first heat exchanger (3). A second expansion valve (351) is provided on the reversing pipe (35).

6. A self-preheating and antifreeze fresh air handling unit according to claim 1, characterized in that: The air inlet channel (51) is vertical, and a pull rod (6) is vertically installed on the housing (1). The pull rod (6) passes through the air inlet channel (51), and a filter screen (7) is fixed on the pull rod (6). An avoidance opening (17) is provided on the lower side of the housing (1). The avoidance opening (17) is located directly below the filter screen (7). A sealing plate (8) for closing the avoidance opening (17) is also provided on the housing (1).

7. A self-preheating and antifreeze fresh air handling unit according to claim 6, characterized in that: A cutting frame (71) is fixed to the periphery of the filter screen (7) plate. The periphery of the cutting frame (71) abuts against the side wall of the air inlet channel (51) and slides in cooperation with the air inlet channel (51). The sealing plate (8) is detachably fixed to the lower side of the pull rod (6).

8. A self-preheating and antifreeze fresh air handling unit according to claim 6 or 7, characterized in that: A tension spring (61) is fixed between the upper end of the pull rod (6) and the upper side wall of the housing (1). The filter screen (7) and the pull rod (6) are detachably fixed.

Images