Energy-saving air conditioning unit
By introducing a return air handling system and a spray system into the air conditioning system of the converter valve hall, the problem of high energy consumption of traditional air conditioning systems has been solved, achieving energy reduction and carbon emission reduction, and meeting the needs of green and low-carbon development.
Patent Information
- Application Number
- CN202423077067.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-12
- Publication Date
- 2025-10-28
- Estimated Expiration
- 2034-12-12
AI Technical Summary
The traditional converter valve hall air-conditioning system has high energy consumption, which leads to increased operating costs and does not meet the requirements of the "dual carbon" policy.
An energy-saving air conditioning unit is adopted, which includes a main air handling system and a return air handling system. The return air handling system exchanges heat with the fresh air through the air heat exchanger, thereby reducing the return air temperature. The spray system is used to further cool the mixed air and reduce the cooling load on the surface heat exchanger.
Significantly reduce the energy consumption of air conditioning units in the converter valve hall, reduce power transmission energy costs, and lower carbon emissions, thus promoting the green and low-carbon development of converter stations.
Smart Images
Figure CN223484395U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of air conditioning technology, and more specifically, to an energy-saving air conditioning unit. Background Technology
[0002] More and more high-voltage transmission buildings will be constructed in western my country, with converter stations being one of the most important. A converter station is a site built in a high-voltage direct current (HVDC) transmission system to convert AC to DC power and meet the power system's requirements for safety, stability, and power quality. The main equipment and facilities included in a converter station are: converter valves, converter transformers, smoothing reactors, control and protection devices, external grounding electrodes, and remote communication systems. The converter valve hall is the core of the converter station's architecture, housing the converter valves and related equipment.
[0003] As a key component in power conversion, the converter valve generates a significant amount of heat during operation. Therefore, an air conditioning system is typically required to maintain suitable temperature and humidity within the converter valve chamber to ensure stable operation and extend its service life. To guarantee the normal operation of the converter valve chamber and minimize interference from outdoor air (especially in the northwestern Gobi Desert region with frequent sandstorms), minimum fresh air intake is usually adopted, maintaining a pressure difference of 5–10 Pa between the converter valve chamber and the outside environment. Return air constitutes a large portion of the total airflow. Furthermore, while national standards specify a temperature range of 10–50℃ for the converter valve chamber, in actual operation, to ensure the stability of the converter valve, the temperature is usually controlled below 35℃.
[0004] Traditional converter valve hall air conditioning systems typically mix fresh air and return air directly, then cool and dehumidify the mixed air through surface cooling coils before sending it into the converter valve hall. Therefore, traditional converter valve hall air conditioning systems need to handle both the fresh air load and the return air load below 35°C. This approach results in high energy consumption for conventional air conditioning systems. High energy consumption not only increases operating costs but also contradicts the "dual carbon" policy. Utility Model Content
[0005] The present invention aims to overcome at least one of the defects of the prior art and provide an energy-saving air conditioning unit to solve the problem of high energy consumption.
[0006] The technical solution adopted by this utility model is to provide an energy-saving air conditioning unit, including a main air handling system and a return air handling system;
[0007] The main air handling system includes a first fresh air inlet, a mixing section and an air outlet connected in sequence. A surface cooling heat exchanger and a first fan are arranged in sequence between the mixing section and the air outlet.
[0008] The return air handling system includes a second fresh air inlet, a return air inlet, a return air outlet, an exhaust vent, and an air heat exchanger. The fresh air input from the second fresh air inlet and the return air input from the return air inlet exchange heat through the air heat exchanger. The second fresh air inlet is connected to the exhaust vent via the air heat exchanger. The return air inlet is connected to the return air outlet via the air heat exchanger. A second fan is provided between the air heat exchanger and the exhaust vent. The return air outlet is connected to the mixing section.
[0009] This solution incorporates a return air handling system. The return air from the converter valve hall enters the air heat exchanger through the return air inlet and exchanges heat with the natural air input from the second fresh air inlet, reducing the temperature of the return air entering the mixing section through the return air outlet. The air then mixes and exchanges heat with the natural air input from the first fresh air inlet, resulting in further cooled mixed air. This significantly reduces the cooling load on the surface heat exchanger, thereby lowering the energy consumption of the air conditioning unit in the converter valve hall, reducing power transmission costs, providing a stable operating environment for the converter valve, and reducing carbon emissions from the converter station, thus promoting the green and low-carbon development of the converter station.
[0010] In some embodiments, a spray system is provided between the second fresh air inlet and the air heat exchanger, the spray system being used to cool the fresh air input into the second fresh air inlet.
[0011] In some embodiments, the spray system includes a wet film, a spray device, a water tank, and a spray circulation pump. The wet film is disposed between the second fresh air inlet and the air heat exchanger. The spray device is used to spray coolant onto the wet film. The water tank is disposed below the spray device and the wet film. The spray circulation pump is connected at both ends to the water tank and the spray device, respectively.
[0012] This solution reduces the temperature of the natural air at the second fresh air inlet through a spray system, thereby increasing the cooling effect of the natural air on the return air in the converter valve hall via the air heat exchanger.
[0013] In some embodiments, a replenishment system connected to the water tank is also provided.
[0014] In some embodiments, the replenishment system includes a water supply line and a drain line, which are respectively connected to the water tank.
[0015] In some embodiments, a liquid level sensor is provided inside the water tank.
[0016] This solution uses a liquid level sensor to obtain the real-time liquid level in the water tank, which facilitates timely replenishment of the water tank through the liquid replenishment system.
[0017] In some embodiments, a first electric heater is provided between the first fresh air inlet and the mixing section; and / or, a second electric heater is provided between the surface cooling heat exchanger and the air outlet.
[0018] This scheme facilitates the preheating of the fresh air at the first return air inlet by the first electric heater under heating conditions, thereby mixing it with the return air input at the return air outlet to increase the temperature of the mixed air, and / or facilitates the heating of the mixed air in the mixing section by the second electric heater under heating conditions, thereby stably supplying hot air to the converter valve hall.
[0019] In some embodiments, a first air filter is provided between the first fresh air inlet and the mixing section; and / or, a second air filter is provided between the mixing section and the surface cooling heat exchanger; and / or, a third air filter is provided between the first fan and the air outlet.
[0020] In some embodiments, a humidity regulating device is provided between the surface heat exchanger and the air outlet.
[0021] In some embodiments, a first temperature and humidity sensor is provided for detecting the fresh air input at the first fresh air inlet; and / or, a second temperature and humidity sensor is provided for detecting the fresh air input at the second fresh air inlet; and / or, a third temperature and humidity sensor is provided for detecting the return air input at the return air inlet; and / or, a fourth temperature and humidity sensor is provided for detecting the mixed air in the mixing section; and / or, a fifth temperature and humidity sensor is provided for detecting the output air at the air outlet.
[0022] This solution uses temperature and humidity sensors to obtain the temperature and humidity at various locations, making it easy to adjust the operating status according to the corresponding temperature and humidity conditions.
[0023] Compared with the prior art, the beneficial effects of this utility model are as follows: by setting up a return air handling system, heat exchange can be carried out between the lower temperature outdoor air and the return air in the converter valve hall. In addition, after spraying the air through the spray system, the temperature of the fresh air in the return air handling system can be further reduced. Thus, the return air can be pre-cooled by outdoor air almost all year round, which significantly reduces the cooling load borne by the heat exchanger in the main air handling system. This not only greatly reduces the energy consumption of the air conditioning unit in the converter valve hall and reduces the cost of power transmission, but also provides a good and stable operating environment for the converter valve, and reduces the carbon emissions of the converter station, promoting the green and low-carbon development of the converter station. Attached Figure Description
[0024] Figure 1 This is a structural diagram of Example 1.
[0025] Figure 2 This is a structural diagram of the return air treatment system in Example 1.
[0026] Figure 3 This is a structural diagram of the spray system in Example 1.
[0027] Figure 4 This is a structural diagram of Example 2.
[0028] Attached reference numerals: 1. First fresh air inlet; 2. Main air handling system; 3. First air filter; 4. First electric heater; 5. Mixing section; 6. Second air filter; 7. Surface heat exchanger; 8. Water supply interface; 9. Water return interface; 10. Second electric heater; 11. Third air filter; 12. Air outlet; 13. First fan; 14. Humidity control device; 15. Exhaust outlet; 16. Second fan; 17. Air heat exchanger; 18. Return air inlet; 19. Wet film; 20. Spray head; 21. Spray pipe; 22. Return air vent. 22. Treatment system; 23. Second fresh air inlet; 24. Spray suction pipe; 25. Suction end; 26. Spray water supply pipe; 27. Spray pipe inlet; 28. Water tank; 29. Return air outlet; 30. Spray circulation pump; 31. Liquid level sensor; 32. Water supply switch valve; 33. Water supply pipeline; 34. Water drain pipeline; 35. Water drain switch valve; 36. Water filter; 37. Spray device; 38. Fresh air temperature and humidity sensor; 39. Return air temperature and humidity sensor; 40. Mixed air temperature and humidity sensor; 41. Supply air temperature and humidity sensor. Detailed Implementation
[0029] The accompanying drawings are for illustrative purposes only and should not be construed as limiting the scope of this invention. To better illustrate the following embodiments, some components in the drawings may be omitted, enlarged, or reduced, and do not represent the actual dimensions of the product. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.
[0030] Example 1
[0031] like Figure 1 As shown, this embodiment provides an energy-saving air conditioning unit, including a main air handling system 2 and a return air handling system 22;
[0032] The main air handling system 2 includes a first fresh air inlet 1, a mixing section 5 and an air outlet 12 connected in sequence. A surface cooling heat exchanger 7 and a first fan 13 are arranged in sequence between the mixing section 5 and the air outlet 12.
[0033] The return air handling system 22 includes a second fresh air inlet 23, a return air inlet 18, a return air outlet 29, an exhaust outlet 15, and an air heat exchanger 17. The fresh air entering through the second fresh air inlet 23 and the return air entering through the return air inlet 18 exchange heat through the air heat exchanger 17. The second fresh air inlet 23 is connected to the exhaust outlet 15 through the air heat exchanger 17, and the return air inlet 18 is connected to the return air outlet 29 through the air heat exchanger 17. A second fan 16 is provided between the air heat exchanger 17 and the exhaust outlet 15. The return air outlet 29 is connected to the mixing section 5.
[0034] In practice, the return air vent of the converter valve hall is connected to the return air inlet 18. During cooling operation, the return air of the converter valve hall enters the air heat exchanger through the return air inlet 18 and indirectly exchanges heat with the outdoor fresh air input by the second fresh air inlet 23, reducing the return air temperature input to the mixing section 5 through the return air outlet 29. At the same time, the fresh air with increased temperature after heat exchange is driven by the second fan 16 and discharged to the outside again through the exhaust outlet 15. After that, the return air cooled by natural wind mixes with the outdoor fresh air input by the first fresh air inlet 1 in the mixing section 5, further reducing the return air temperature. After that, it is cooled by the surface cooling heat exchanger 7 of the main air handling system 2. The cooled mixed air is then supplied to the converter valve hall by the first fan 13. During this process, the return air is cooled by the cold source provided by natural wind, which can significantly reduce the cooling load of the surface cooling heat exchanger 7. This helps to reduce the energy consumption of the air conditioning unit in the converter valve hall, reduce power transmission costs, provide a good and stable operating environment for the converter valve, and reduce the carbon emissions of the converter station, promoting the green and low-carbon development of the converter station. In actual use, the return air temperature in the valve hall is usually set at 35℃. Therefore, as long as the air temperature facing the first fresh air inlet 1 of the air heat exchanger 17 is lower than 35℃, it will have a cooling effect on the return air in the converter valve hall. In actual application in the Northwest region, the outdoor air temperature is lower than 35℃ for more than 90% of the year. Since the converter valve hall generates a lot of heat, it needs to operate in cooling mode for most of the year. Therefore, the return air can be cooled by the natural wind provided by the return air handling system 22 for most of the year. (Continue to refer to...) Figure 1 The surface cooling heat exchanger 7 is equipped with a water supply interface 8 and a water return interface 9. Under cooling conditions, low-temperature coolant is introduced into the surface cooling heat exchanger 7 through the water supply interface 8. After heat exchange, the heated coolant flows out through the water return interface 9 to form a coolant circulation.
[0035] like Figure 1-3As shown, to improve the cooling effect of natural wind, a spray system is installed between the second fresh air inlet 23 and the air heat exchanger 17. Specifically, the spray system includes a wet film 19, a spray device 37, a water tank 28, and a spray circulation pump 30. The wet film 19 is located between the second fresh air inlet 23 and the air heat exchanger 17. The spray device 37 sprays coolant onto the wet film 19. The water tank 28 is located below the spray device 37 and the wet film 19. The spray circulation pump 30 is connected to the water tank 28 and the spray device 37 at both ends. (Continue to refer to...) Figure 2 , Figure 3 The wet film 19 completely blocks the space between the second fresh air inlet 23 and the air heat exchanger 17. The spray device 37 includes a connected spray pipe 21 and a spray head 20. The spray head 20 covers the surface of the wet film 19. The spray pipe inlet 27 is connected to the output end of the spray circulation pump 30 through the spray water supply pipe 26. A spray suction pipe 24 is connected between the input end of the spray circulation pump 30 and the water tank 28. In order to make full use of the coolant in the water tank 28, the suction end 25 of the spray suction pipe 24 is connected to the lower part or bottom of the water tank 28. In order to avoid blockage of the spray device 37 and the spray circulation pump 30, a water filter 36 is also provided on the spray suction pipe 24. In actual operation, after water is sprayed through the spray system, the air temperature input to the second fresh air inlet 23 is close to the dew point temperature of the outdoor air. Therefore, while cooling down, the effective operating time of natural cooling is extended.
[0036] like Figure 2-3 As shown, a replenishment system connected to the water tank 28 is also provided to facilitate the adjustment of the coolant volume of the spray system. For specific implementation, please refer to [reference needed]. Figure 3 The replenishment system includes a water replenishment pipe 33 and a water drain pipe 34, which are respectively connected to the water tank 28. The water replenishment pipe 33 is equipped with a water replenishment switch valve 32, and the water drain pipe 34 is equipped with a water drain switch valve 35. In order to improve the efficiency of replenishment and drainage, the water drain pipe 34 is connected to the bottom of the water tank 28, while the water replenishment pipe 33 is connected to the top of the water tank 28.
[0037] like Figure 3 As shown, in order to facilitate monitoring of the coolant level in the water tank 28, a level sensor 31 is installed inside the water tank 28. In specific implementation, a main control system is also provided. The level sensor 31, the drain valve 35, and the water supply valve 32 are all electrically connected to the main control system, so that the water tank 28 can be replenished in a timely manner by opening the water supply valve 32, or the water tank 28 can be drained by opening the drain valve 35.
[0038] like Figure 1 As shown, in order to meet the needs of heating operation, a first electric heater 4 is provided between the first fresh air inlet 1 and the mixing section 5; and / or, a second electric heater 10 is provided between the surface cooling heat exchanger 7 and the air outlet 12.
[0039] In practice, when the temperature inside the converter valve hall is lower than the preset temperature requirement, the heating mode is activated. At this time, the air heat exchanger side of the return air handling system 22 no longer introduces natural air through the second fresh air inlet 23. That is, the return air from the converter valve hall does not undergo heat exchange after passing through the air heat exchanger and is directly input into the mixing section 5 through the return air outlet 29. In the mixing section 5, the natural air from the first fresh air inlet 1 is preheated by the first electric heater 4, thereby increasing the temperature of the mixed air after mixing with the return air and reducing the heat load of the surface cooling heat exchanger 7. In addition, the mixed air in the mixing section 5 can be further heated by the second electric heater 10, thereby stably supplying hot air to the converter valve hall.
[0040] like Figure 1 As shown, a first air filter 3 is provided between the first fresh air inlet 1 and the mixing section 5; and / or, a second air filter 6 is provided between the mixing section 5 and the surface cooling heat exchanger 7; and / or, a third air filter 11 is provided between the first fan 13 and the air outlet 12. The first air filter 3 filters the fresh air input from the first fresh air inlet 1, the second air filter 6 filters the mixed air from the mixing section 5 to the air outlet 12, and the third air filter 11 further filters the air input into the converter valve hall. This prevents dust and dirt brought in from accumulating inside the air conditioning unit, reducing the operating and maintenance costs of the air conditioning unit.
[0041] like Figure 1 As shown, in order to ensure that the air input to the converter valve hall meets the preset humidity requirements, a humidity regulating device 14 is provided between the surface cooling heat exchanger 7 and the air outlet 12. The temperature and humidity regulating device 14 is electrically connected to the main control system, thereby facilitating automatic control.
[0042] refer to Figure 1-3 The specific working process of this embodiment is as follows:
[0043] During cooling operation, outdoor fresh air enters the return air handling system 22 through the second return air inlet, and is then cooled down by the spray system. At this time, the fresh air temperature drops to about the outdoor air dew point temperature. Then it enters the air heat exchanger 17 and exchanges heat with the high-temperature return air entering from the return air inlet 18. At this time, the return air temperature drops significantly (but is still above the outdoor dew point temperature), and the fresh air temperature rises. The fresh air with the increased temperature is then discharged to the outside through the exhaust outlet 15 under the drive of the second fan 16.
[0044] Another portion of fresh air enters the main air handling system 2 through the first fresh air inlet 1, then passes through the first air filter 3, and then through the first electric heater 4 (which is turned off at this time) before entering the mixing section 5. Simultaneously, return air cooled by the return air handling system 22 also enters the main air handling system 2 through the return air outlet 29. In the mixing section 5, the return air mixes with the fresh air, and then the mixed air passes through the second air filter 6 and enters the surface cooling heat exchanger 7. Low-temperature coolant is introduced into the surface cooling heat exchanger 7, cooling and dehumidifying the mixed air. The low-temperature coolant enters through the water supply interface 8 and exits through the water return interface 9. Subsequently, the low-temperature, low-humidity air flows through the second electric heater 10 and the humidity control device 14, and is sequentially sent through the first fan 13, the third air filter 11, and the air outlet 12 into the converter valve hall. During this process, both the second electric heater 10 and the humidity control device 14 are turned off.
[0045] For the spray system, spray water enters the spray suction pipe 24 through the suction end 25, is filtered by the water filter 36, and then enters the spray circulation pump 30. Subsequently, it enters the spray pipe 21 through the spray pipe inlet 27 via the spray water supply pipe 26. The spray pipe 21 delivers the spray water to the evenly distributed spray heads 20, sprays it into the air, and then it falls into the water tank 28 or flows into the water tank 28 along the wet film 19, completing the spray cycle. As the spray water evaporates and is consumed, when the liquid level sensor 31 detects that the liquid level in the water tank 28 is lower than the lower limit, the water replenishment valve 32 is opened to replenish water. When the water level reaches the upper limit, the water replenishment valve 32 is closed.
[0046] During heating operation, the sprinkler system is shut down, the drain valve 35 is opened to drain the water from the sprinkler system, and the second fan 16 is shut down. Return air from the converter valve hall enters the return air handling system 22 through the return air inlet 18, then passes through the air heat exchanger 17 and return air outlet 29 into the mixing section 5. At this time, only return air flows through the air heat exchanger 17; no fresh air flows through the other side. Fresh air that needs to be supplied into the converter valve hall enters the main air handling system 2 through the first fresh air inlet 1, then passes through the first air filter 3, and then through the first electric heater 4 into the mixing section 5. The first electric heater 4 is adjusted according to actual heating needs. The mixed air then passes through the second air filter 6 into the surface cooling heat exchanger 7. Hot water is introduced into the surface cooling heat exchanger 7 through the supply water inlet 8 and the return water inlet 9, thus heating the mixed air. Subsequently, the high-temperature mixed airflow passes through the second electric heater 10 and the humidity regulating device 14, and is sent into the converter valve hall through the first fan 13, the third air filter 11, and the air outlet 12. During this process, the heating amount of the second electric heater 10 and the humidification amount of the humidity regulating device 14 are adjusted according to the temperature and humidity of the converter valve hall.
[0047] Example 2
[0048] like Figure 4As shown, this embodiment, based on embodiment 1, further includes a first temperature and humidity sensor for detecting the fresh air input to the first fresh air inlet 1, a second temperature and humidity sensor for detecting the fresh air input to the second fresh air inlet 23, a third temperature and humidity sensor for detecting the return air input to the return air inlet 18, a fourth temperature and humidity sensor for detecting the mixed air in the mixing section 5, and a fifth temperature and humidity sensor for detecting the output air from the air outlet 12.
[0049] In practical implementation, since both the first fresh air inlet 1 and the second fresh air inlet 23 are supplied with natural air, to simplify the unit structure, the first fresh air inlet 1 and the second fresh air inlet 23 can be placed close together, so that only one fresh air temperature and humidity sensor 38 is needed to meet the temperature and humidity detection requirements of the two fresh air inlets. Specifically, in order to obtain accurate temperature and humidity data, a return air temperature and humidity sensor 39 is installed at the connection between the return air inlet 18 and the converter valve hall; a mixed air temperature and humidity sensor 40 is installed at the end of the mixed air section 5; and a supply air temperature and humidity sensor 41 is installed at the connection between the supply air outlet 12 and the converter valve hall. For the convenience of automated control, the fresh air temperature and humidity sensor 38, the return air temperature and humidity sensor 39, the mixed air temperature and humidity sensor 40, and the supply air temperature and humidity sensor 41 are all electrically connected to the main control system.
[0050] In actual operation, based on the temperature and humidity data from the fresh air temperature and humidity sensor 38, the return air temperature and humidity sensor 39, the mixed air temperature and humidity sensor 40, and the supply air temperature and humidity sensor 41, the first electric heater 4, the second electric heater 10, the humidity regulating device 14, the spray system, and the liquid replenishment system are adaptively adjusted to achieve the best working conditions.
[0051] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating the technical solution of this utility model, and are not intended to limit the specific implementation of this utility model. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the claims of this utility model should be included within the protection scope of the claims of this utility model.
Claims
1. An energy-saving air conditioning unit, characterized in that, This includes the main air handling system and the return air handling system; The main air handling system includes a first fresh air inlet, a mixing section and an air outlet connected in sequence. A surface cooling heat exchanger and a first fan are arranged in sequence between the mixing section and the air outlet. The return air handling system includes a second fresh air inlet, a return air inlet, a return air outlet, an exhaust vent, and an air heat exchanger. The fresh air input from the second fresh air inlet and the return air input from the return air inlet exchange heat through the air heat exchanger. The second fresh air inlet is connected to the exhaust vent via the air heat exchanger, and the return air inlet is connected to the return air outlet via the air heat exchanger. A second fan is provided between the air heat exchanger and the exhaust vent, and the return air outlet is connected to the mixing section.
2. The energy-saving air conditioning unit according to claim 1, characterized in that, A spray system is provided between the second fresh air inlet and the air heat exchanger, and the spray system is used to cool the fresh air input into the second fresh air inlet.
3. The energy-saving air conditioning unit according to claim 2, characterized in that, The spray system includes a wet film, a spray device, a water tank, and a spray circulation pump. The wet film is located between the second fresh air inlet and the air heat exchanger. The spray device is used to spray coolant onto the wet film. The water tank is located below the spray device and the wet film. The spray circulation pump is connected to the water tank and the spray device at both ends.
4. The energy-saving air conditioning unit according to claim 3, characterized in that, It is also equipped with a liquid replenishment system that is connected to the water tank.
5. The energy-saving air conditioning unit according to claim 4, characterized in that, The fluid replenishment system includes a water replenishment pipeline and a water drain pipeline, which are respectively connected to the water tank.
6. The energy-saving air conditioning unit according to claim 5, characterized in that, The water tank is equipped with a liquid level sensor.
7. The energy-saving air conditioning unit according to any one of claims 1-6, characterized in that, A first electric heater is provided between the first fresh air inlet and the mixing section; and / or, A second electric heater is provided between the surface heat exchanger and the air outlet.
8. The energy-saving air conditioning unit according to any one of claims 1-6, characterized in that, A first air filter is provided between the first fresh air inlet and the mixing section; and / or, A second air filter is provided between the mixing section and the surface heat exchanger, and / or, A third air filter is provided between the first fan and the air outlet.
9. The energy-saving air conditioning unit according to any one of claims 1-6, characterized in that, A humidity regulating device is provided between the surface heat exchanger and the air outlet.
10. The energy-saving air conditioning unit according to any one of claims 1-6, characterized in that, It also includes a first temperature and humidity sensor for detecting the fresh air input into the first fresh air inlet; and / or, It also includes a second temperature and humidity sensor for detecting the fresh air input to the second fresh air inlet; and / or, It also includes a third temperature and humidity sensor for detecting the return air input at the return air inlet; and / or, It also includes a fourth temperature and humidity sensor for detecting the mixed air in the mixing section; and / or, It also includes a fifth temperature and humidity sensor for detecting the output air from the air outlet.