Fresh air circulating device of clean workshop air-conditioning system and control method of fresh air circulating device

Abstract

The invention relates to a fresh air circulation device of a clean workshop air conditioning system and a control method thereof, and the fresh air circulation device of the clean workshop air conditioning system comprises a pipeline structure, an FFU air supply unit, a sensor assembly, a plurality of electric valves and a circuit board assembly, the pipeline structure comprises a communicating pipe and is provided with an air inlet allowing outdoor air to enter, a tail gas inlet allowing tail gas to enter, a tail gas outlet allowing tail gas to be exhausted and a main air outlet, and the tail gas inlet communicates with the main air outlet through the communicating pipe. An air inlet of the FFU is communicated with the main air outlet; the sensor assembly is arranged at the tail gas inlet and used for detecting the air speed, the tail gas humidity, the temperature and the dust concentration at the tail gas inlet. The plurality of electric valves comprise a first electric valve arranged at the tail gas outlet, a second electric valve arranged in the middle of the communicating pipe and a third electric valve arranged at the air inlet; the circuit board assembly is electrically connected with the sensor assembly and the electric valves. The problem that an existing air conditioning system is large in energy consumption is solved.

Description

Technical Field

[0001] The present invention relates to the field of optical fiber preform clean room, and in particular to a fresh air circulation device of a clean room air conditioning system and a control method thereof. Background Art During the production process of optical fiber preforms, there are high requirements for the cleanliness, temperature and humidity of the production environment. The air conditioning system provides clean air with appropriate temperature and humidity for the clean room required by the optical fiber preform. In order to maintain the cleanliness of the clean room, the clean room needs to maintain a continuous positive pressure to the outside. This function is achieved through the fresh air supply unit FFU of the air conditioning system. The FFU air supply unit sends the fresh air outside the clean room through the filter to the AHU air supply unit. The AHU mixes the fresh air with the return air in the clean room and then sends it to the room through the filter and the hot and cold water coil to achieve the control of temperature, humidity and cleanliness, while maintaining the relative positive pressure of the clean room to the outside of the factory.

[0002] Since the outdoor air contains a lot of dust and moisture, a large number of air conditioning filters are needed to filter out the dust in the air, the cold water coil consumes chilled water to remove excess moisture in the air, and the hot water pan adjusts the air temperature, which consumes a lot of energy. Summary of the invention

[0003] Based on the above description, the present invention provides a fresh air circulation device for a clean workshop air conditioning system to solve the problem of high energy consumption of the existing air conditioning system.

[0004] The technical solution of the present invention to solve the above technical problems is as follows: A fresh air circulation device for a clean workshop air conditioning system, comprising: The pipeline structure includes a connecting pipe, and has an air inlet for outdoor air to enter, a tail gas inlet for tail gas treated by a tail gas treatment tower to enter, a tail gas outlet for tail gas to be discharged, and a main outlet, wherein the tail gas inlet and the main outlet are connected through the connecting pipe; FFU air supply unit, whose air inlet is connected to the main air outlet; a sensor assembly, disposed at the exhaust air inlet, for detecting wind speed, exhaust gas humidity, temperature and dust concentration at the exhaust air inlet; and, a plurality of electric valves, including a first electric valve disposed at the exhaust gas outlet, a second electric valve disposed at the middle of the connecting pipe, and a third electric valve disposed at the air inlet; and, A circuit board assembly is electrically connected to the sensor assembly and the plurality of electric valves.

[0005] On the basis of the above technical solution, the present invention can also be improved as follows: Furthermore, the pipeline assembly also includes: An exhaust pipe, the two ends of which respectively constitute the exhaust air inlet and the exhaust air outlet, and the middle part of the exhaust pipe is connected to one end of the connecting pipe; and An air intake pipe, one end of which is connected to the middle of the connecting pipe, and the other end of which constitutes the main air outlet; The other end of the connecting pipe constitutes the air inlet; The second electric valve is located between the tail pipe and the intake pipe.

[0006] Furthermore, the sensor assembly is arranged in the exhaust pipe and close to the exhaust air inlet. The sensor assembly includes a first sensor group and a wind speed sensor. The first sensor group is used to detect the exhaust humidity, temperature and dust concentration at the exhaust air inlet.

[0007] Furthermore, the first sensor group and the wind speed sensor are distributed at intervals along the flow direction of the exhaust gas, and the first sensor group is arranged close to the exhaust gas inlet.

[0008] Furthermore, the pipeline structure also includes a filter tube, a filter element is arranged in the filter tube, one end of the filter tube is connected to the tail pipe, the other end is connected to the intake pipe, and the filter tube is arranged close to the sensor assembly; The plurality of electric valves further include a fourth electric valve disposed in the filter tube and located between the filter element and the tail gas pipe, and the fourth electric valve is electrically connected to the circuit board assembly.

[0009] Furthermore, the filter tube comprises: At least two first pipe sections, the two first pipe sections are coaxially arranged and respectively connected to the tail pipe and the intake pipe, and threaded holes are formed at the ends of the two first pipe sections that are close to each other, and the threaded rotation directions of the two threaded holes are opposite; and at least one second pipe segment, two ends of the second pipe segment being respectively screwed to the two threaded holes; The filter element is installed in the second pipe section.

[0010] Furthermore, a second sensor group is provided at the main air outlet, the second sensor group is electrically connected to the circuit board assembly and is used to detect the exhaust humidity, temperature and dust concentration at the main air outlet.

[0011] Furthermore, a fresh air circulation device of a clean workshop air conditioning system also includes an AHU air supply unit, the air inlet of the AHU air supply unit is connected to the air outlet of the FFU air supply unit, and the air outlet of the AHU air supply unit is used to connect with the clean workshop.

[0012] The present invention also proposes a control method for a fresh air circulation device of a clean room air conditioning system, and the control method is applied to the fresh air circulation device of the clean room air conditioning system, comprising: Obtaining wind speed, temperature, humidity and dust concentration at the exhaust gas inlet; The communication states of the first electric valve, the second electric valve, and the third electric valve are controlled according to at least one of wind speed, temperature, humidity, and dust concentration.

[0013] Furthermore, the pipeline structure also includes a filter tube, a filter element is arranged in the filter tube, one end of the filter tube is connected to the tail pipe, the other end is connected to the intake pipe, and the filter tube is arranged close to the sensor assembly; The plurality of electric valves further include a fourth electric valve disposed in the filter tube and located between the filter element and the tailpipe, the fourth electric valve being electrically connected to the circuit board assembly; Controlling the connection state of the first electric valve, the second electric valve and the third electric valve according to wind speed, temperature, humidity and dust concentration includes: If the wind speed, temperature, humidity and dust concentration are all within the first set range, the first electric valve, the third electric valve and the fourth electric valve are controlled to be closed, and the second electric valve is opened; If at least one of the wind speed, temperature and dust concentration is outside a first set range, the first electric valve and the third electric valve are controlled to be opened, and the second electric valve and the fourth electric valve are controlled to be closed; If the wind speed, temperature, and dust concentration are all within the first setting range, and the humidity is outside the first setting range and within the second setting range, the first electric valve, the second electric valve, and the third electric valve are controlled to be closed, and the fourth electric valve is controlled to be opened.

[0014] Compared with the prior art, the technical solution of this application has the following beneficial technical effects: When the sensor assembly detects that exhaust gas is discharged from the exhaust air inlet and the temperature, humidity and dust concentration of the incoming exhaust gas are within the set range, the exhaust gas is qualified exhaust gas, so the second electric valve is opened, the first electric valve and the third electric valve are closed, so that the qualified exhaust gas enters the FFU air supply unit through the total air inlet. Since the dust content in the exhaust gas discharged from the exhaust treatment tower is low and the temperature is close to that of the clean workshop, a large amount of air conditioner and air conditioning system cold and hot water consumption can be saved, thereby reducing costs and saving energy.

[0015] On the contrary, when the sensor component detects that no exhaust gas is discharged from the exhaust gas inlet, or at least one of the temperature and dust concentration of the incoming exhaust gas is outside the set range, the exhaust gas is unqualified exhaust gas, so the first electric valve and the third electric valve are opened, and the second electric valve is closed, so that the unqualified exhaust gas is discharged from the exhaust gas outlet, and the outdoor air enters from the air inlet and enters the FFU air supply unit from the main air inlet, so as to ensure the cleanliness of the clean room. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A schematic structural diagram of a fresh air circulation device of a clean workshop air conditioning system provided in an embodiment of the present invention.

[0017] In the accompanying drawings, the components represented by the reference numerals are listed as follows: 1. Pipeline structure; 11. Connecting pipe; 111. Air inlet; 12. Exhaust pipe; 121. Exhaust inlet; 122. Exhaust outlet; 13. Inlet pipe; 131. Main outlet; 14. Filter pipe; 141. First pipe section; 142. Second pipe section; 2. FFU air supply unit; 3. Sensor assembly; 31. First sensor group; 32. Wind speed sensor; 41. First electric valve; 42. Second electric valve; 43. Third electric valve; 44. Fourth electric valve; 6. Second sensor group; 7. AHU air supply unit; a. Exhaust gas treatment tower. DETAILED DESCRIPTION

[0018] In order to facilitate understanding of the present application, the present application will be described more fully below with reference to the relevant drawings. Embodiments of the present application are provided in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive.

[0019] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0020] It will be appreciated that spatial relationship terms such as "under," "beneath," "below," "under," "above," "above," etc., may be used herein to describe the relationship of an element or feature shown in the figures to other elements or features. It will be appreciated that, in addition to the orientations shown in the figures, spatial relationship terms also include different orientations of the device in use and operation. For example, if the device in the accompanying drawings is flipped, an element or feature described as "under other elements" or "under it" or "under it" will be oriented as being "above" the other elements or features. Thus, the exemplary terms "under" and "under" may include both upper and lower orientations. In addition, the device may also include additional orientations (e.g., rotated 90 degrees or other orientations), and the spatial descriptors used herein are interpreted accordingly.

[0021] It should be noted that when an element is considered to be "connected" to another element, it can be directly connected to the other element, or connected to the other element through an intermediate element. The "connection" in the following embodiments should be understood as "electrical connection", "communication connection", etc. if the connected circuits, modules, units, etc. have electrical signals or data transmission between each other.

[0022] When used herein, the singular forms "a", "an", and "said / the" may also include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "include / comprise" or "have" etc. specify the presence of stated features, wholes, steps, operations, components, parts or combinations thereof, but do not exclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts or combinations thereof.

[0023] Please refer to Figure 1The present invention provides a fresh air circulation device for a clean workshop air conditioning system, comprising a pipeline structure 1, an FFU air supply unit 2, a sensor assembly 3, a plurality of electric valves and a circuit board assembly, wherein the pipeline structure 1 comprises a connecting pipe 11, and has an air inlet 111 for outdoor air to enter, an exhaust gas inlet 121 for exhaust gas treated by an exhaust gas treatment tower a to enter, an exhaust gas outlet 122 for exhaust gas to be discharged, and a total outlet 131, wherein the exhaust gas inlet 121, the exhaust gas outlet 122, the air inlet 111 and the total outlet 131 are connected to each other. It is connected through a connecting pipe 11; the air inlet of the FFU air supply unit 2 is connected to the main air outlet 131; the sensor assembly 3 is arranged at the exhaust air inlet 121, and is used to detect the wind speed, exhaust gas humidity, temperature and dust concentration at the exhaust air inlet 121; a plurality of electric valves include a first electric valve 41 arranged at the exhaust air outlet 122, a second electric valve 42 arranged in the middle of the connecting pipe 11 and a third electric valve 43 arranged at the air inlet 111; the circuit board assembly is electrically connected to the sensor assembly 3 and the plurality of electric valves.

[0024] When the sensor assembly 3 detects that exhaust gas is discharged from the exhaust air inlet 121 and the temperature, humidity and dust concentration of the incoming exhaust gas are within the set range, the exhaust gas is qualified exhaust gas, so the second electric valve 42 is opened, the first electric valve 41 and the third electric valve 43 are closed, so that the qualified exhaust gas enters the FFU air supply unit 2 through the total air outlet 131. Since the dust content in the exhaust gas discharged from the exhaust treatment tower a is less and the temperature is close to that of the clean workshop, a large amount of air conditioner and air conditioning system cold and hot water consumption can be saved, thereby reducing costs and saving energy.

[0025] On the contrary, when the sensor component 3 detects that no exhaust gas is discharged from the exhaust gas inlet 121, or at least one of the temperature and dust concentration of the incoming exhaust gas is outside the set range, the exhaust gas is unqualified exhaust gas, so the first electric valve 41 and the third electric valve 43 are opened, and the second electric valve 42 is closed, so that the unqualified exhaust gas is discharged from the exhaust gas outlet, and the outdoor air enters from the air inlet 111 and enters the FFU air supply unit 2 from the main air outlet 131 to ensure the cleanliness of the clean room.

[0026] In the present invention, the specific structure of the pipeline assembly is not limited, as long as the exhaust air inlet 121 and the total air outlet 131 can be connected through the connecting pipe 11. Specifically, the pipeline assembly also includes an exhaust pipe 12 and an intake pipe 13, the two ends of the exhaust pipe 12 respectively constitute the exhaust air inlet 121 and the exhaust air outlet 122, the middle of the exhaust pipe 12 is connected to one end of the connecting pipe 11; one end of the intake pipe 13 is connected to the middle of the connecting pipe 11, and the other end of the intake pipe 13 constitutes the total air outlet 131; the other end of the connecting pipe 11 constitutes the air inlet 111; the second electric valve 42 is located between the exhaust pipe 12 and the intake pipe 13. In this way, the structure is simple and the arrangement is convenient.

[0027] More specifically, in this embodiment, the sensor assembly 3 is arranged in the exhaust pipe 12 and close to the exhaust air inlet 121. The sensor assembly 3 includes a first sensor group 31 and a wind speed sensor 32. The first sensor group 31 is used to detect the exhaust humidity, temperature and dust concentration at the exhaust air inlet 121. The wind speed sensor 32 is used to detect whether the exhaust air outlet 122 discharges exhaust gas. The first sensor group 31 is set as a SX-M real-time multi-point clean environment detection system, which can monitor the temperature, humidity and air cleanliness at the exhaust air inlet 121, wherein the temperature range is 23°C ± 8, the humidity range is less than 80%; the cleanliness range is less than 30000 / m 3 0.5um particle content in the air.

[0028] Further, in this embodiment, the first sensor group 31 and the wind speed sensor 32 are spaced apart along the flow direction of the exhaust gas, and the first sensor group 31 is arranged close to the exhaust gas inlet 121. Thus, the humidity, temperature and cleanliness at the exhaust gas inlet 121 can be detected more accurately.

[0029] In this embodiment, the pipeline structure 1 also includes a filter tube 14, a filter element is provided in the filter tube 14, one end of the filter tube 14 is connected to the exhaust pipe 12, and the other end is connected to the intake pipe 13, and the filter tube 14 is arranged close to the sensor assembly 3; the plurality of electric valves also include a fourth electric valve 44 arranged in the filter tube 14 and located between the filter element and the exhaust pipe 12, and the fourth electric valve 44 is electrically connected to the circuit board assembly.

[0030] It should be noted that the gas discharged from the tail gas treatment tower a has a low dust content, and most of it is the indoor air of the clean workshop, so the temperature is close to that of the clean workshop. When the humidity range of the tail gas entering the tail gas inlet 121 is greater than or equal to 80% and less than 85%, and the cleanliness and temperature are within the set range, the first electric valve 41, the second electric valve 42 and the third electric valve 43 are closed, and the fourth electric valve 44 is opened, so that the tail gas passes through the filter tube 14 and the filter element, so that the humidity of the tail gas is reduced, thereby improving the utilization rate of the tail gas and further saving the consumption of the air conditioning system filter and hot and cold water.

[0031] In order to facilitate the replacement of the filter element, in this embodiment, the filter tube 14 includes at least two first tube sections 141 and at least one second tube section 142. The two first tube sections 141 are coaxially arranged and respectively connected to the tail pipe 12 and the intake pipe 13, and a threaded hole is formed at one end of the two first tube sections 141 that is close to each other, and the thread rotation directions of the two threaded holes are arranged in opposite directions; the two ends of the second tube section 142 are respectively screwed to the two threaded holes; and the filter element is installed in the second tube section 142. Therefore, by rotating the second tube section 142, the two first tube sections 141 can be moved closer to each other or away from each other relative to the second tube section 142, and then the second tube section 142 can be disassembled or installed by rotating the second tube section 142 to facilitate the replacement of the filter element. In this way, disassembly is convenient and operation is simple.

[0032] It should be noted that, in this embodiment, during the disassembly and installation of the second pipe segment 142, there is interference with the two first pipe segments 141, and the exhaust pipe 12 and the connecting pipe are configured as flexible pipes or plastic pipes with a certain elasticity, which does not affect the installation or disassembly of the second pipe segment 142.

[0033] In addition, the number of the first pipe segments 141 and the second pipe segments 142 is not limited, as long as the number of the first pipe segments 141 is always one more than the number of the second pipe segments 141 , and the exhaust pipe 12 and the intake pipe 13 are always directly connected to the corresponding first pipe segments 141 .

[0034] In this embodiment, the type of the filter element is not limited, and it can be at least one of filter cloth, sponge and activated carbon. It is convenient to set up and has low cost.

[0035] In this embodiment, the main air outlet 131 is further provided with a second sensor group 6, which is used to detect the exhaust humidity, temperature and dust concentration at the main air outlet 131. The second sensor group 6 is connected to the circuit board assembly, and the second sensor group 6 is set as a SX-M real-time multi-point clean environment detection system, and can be used as a backup, and can also detect the exhaust entering the main air outlet 131 again, and can judge whether the filter element needs to be replaced according to the humidity of the exhaust gas.

[0036] In this embodiment, a fresh air circulation device of a clean workshop air conditioning system also includes an AHU air supply unit 7, the air inlet of the AHU air supply unit 7 is connected to the air outlet of the FFU air supply unit 2, and the air outlet of the AHU air supply unit 7 is used to communicate with the clean workshop. The FFU air supply unit 2 (Fan Filter Unit) is an air filter system with a built-in fan. The AHU air supply unit 7 (Air handling unit, is a centralized air handling system, a forced hot air heating and ventilation system that distributes heated air through air ducts. The basic centralized system is a full air single-zone system, generally including fans, heaters, coolers and filter components. The fresh air delivered by the AHU air supply unit 7 is mixed with a part of the return air in the room, and then the harmful substances such as dust, smoke, black smoke and organic particles in the air are filtered out through the filter.

[0037] The present invention also provides a control method for a fresh air circulation device of a clean room air conditioning system, comprising: S10, obtaining the wind speed, temperature, humidity and dust concentration at the exhaust gas inlet; S20. Controlling the connection states of the first electric valve, the second electric valve, and the third electric valve according to at least one of wind speed, temperature, humidity, and dust concentration.

[0038] In this embodiment, the wind speed is used to determine whether the exhaust gas treatment tower discharges exhaust gas toward the exhaust gas inlet, and the connectivity status of the first electric valve, the second electric valve and the third electric valve is determined by the temperature, humidity and dust concentration of the exhaust gas at the exhaust gas inlet, so that qualified exhaust gas or outdoor air is filled into the FFU air supply unit.

[0039] Specifically, S20 includes: S21, if the wind speed, temperature, humidity and dust concentration are all within the first set range, control the first electric valve, the third electric valve and the fourth electric valve to close, and the second electric valve to open; S22, if at least one of the wind speed, temperature and dust concentration is outside the first set range, control the first electric valve and the third electric valve to be opened, and the second electric valve and the fourth electric valve to be closed; S23: If the wind speed, temperature, and dust concentration are all within the first setting range, and the humidity is outside the first setting range and within the second setting range, control the first electric valve, the second electric valve, and the third electric valve to close, and the fourth electric valve to open.

[0040] In this embodiment, the wind speed is used to detect whether there is exhaust gas discharged from the exhaust air inlet. The first setting range is: temperature range 23℃±8, humidity range less than 80%; cleanliness range less than 30000 / m 3 The content of 0.5um particles in the air. The second setting range is a humidity range greater than or equal to 80% and less than 85%.

[0041] When it is detected that the exhaust gas enters the exhaust gas inlet and the temperature, humidity and dust concentration are all within the first set range, the first electric valve, the third electric valve and the fourth electric valve are closed, and the second electric valve is opened to allow qualified exhaust gas to enter the FFU air supply unit.

[0042] When it is detected that the exhaust gas enters the exhaust gas inlet, and the temperature and dust concentration are within the first set range, and the humidity is within the second set range, the first electric valve, the second electric valve and the third electric valve are closed, and the fourth electric valve is opened, so that the exhaust gas enters the filter tube for filtration and enters the FFU air supply unit after the humidity is reduced.

[0043] When it is detected that there is no exhaust gas or the flow rate is extremely small and close to zero, or at least one of the temperature and dust concentration exceeds the first set range, or the humidity exceeds the second range, the first electric valve and the third electric valve are opened, and the second electric valve and the fourth electric valve are closed, so that the exhaust gas is discharged from the exhaust outlet to the outside through the exhaust pipe, and the outdoor air enters the FFU air supply unit from the air inlet through the air inlet pipe. In this way, multiple electric valves can be selectively opened and closed to make full use of the exhaust gas, reasonably save the energy of the air conditioning system, and ensure the cleanliness of the clean room.

[0044] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A fresh air circulation device for a clean room air conditioning system, characterized in that: include: The pipeline structure includes a connecting pipe, and has an air inlet for outdoor air to enter, a tail gas inlet for tail gas treated by a tail gas treatment tower to enter, a tail gas outlet for tail gas to be discharged, and a main outlet, wherein the tail gas inlet and the main outlet are connected through the connecting pipe; FFU air supply unit, whose air inlet is connected to the main air outlet; A sensor assembly, disposed at the exhaust air inlet, for detecting wind speed, exhaust gas humidity, temperature and dust concentration at the exhaust air inlet; A plurality of electric valves, including a first electric valve disposed at the exhaust gas outlet, a second electric valve disposed at the middle of the connecting pipe, and a third electric valve disposed at the air inlet; as well as, A circuit board assembly is electrically connected to the sensor assembly and the plurality of electric valves.

2. A fresh air circulation device for a clean room air conditioning system according to claim 1, characterized in that: The pipeline assembly also includes: An exhaust pipe, the two ends of which respectively constitute the exhaust air inlet and the exhaust air outlet, and the middle part of the exhaust pipe is connected to one end of the connecting pipe; and An air intake pipe, one end of which is connected to the middle of the connecting pipe, and the other end of which constitutes the main air outlet; The other end of the connecting pipe constitutes the air inlet; The second electric valve is located between the tail pipe and the intake pipe.

3. A fresh air circulation device for a clean room air conditioning system according to claim 2, characterized in that: The sensor assembly is arranged in the exhaust pipe and close to the exhaust air inlet. The sensor assembly includes a first sensor group and a wind speed sensor. The first sensor group is used to detect the exhaust humidity, temperature and dust concentration at the exhaust air inlet.

4. A fresh air circulation device for a clean room air conditioning system according to claim 3, characterized in that: The first sensor group and the wind speed sensor are distributed at intervals along the flow direction of the exhaust gas, and the first sensor group is arranged close to the exhaust gas inlet.

5. The fresh air circulation device of the clean room air conditioning system according to claim 2, characterized in that: The pipeline structure further includes a filter tube, a filter element is arranged in the filter tube, one end of the filter tube is connected to the tail pipe, the other end is connected to the intake pipe, and the filter tube is arranged close to the sensor assembly; The plurality of electric valves further include a fourth electric valve disposed in the filter tube and located between the filter element and the tail gas pipe, and the fourth electric valve is electrically connected to the circuit board assembly.

6. A fresh air circulation device for a clean room air conditioning system according to claim 5, characterized in that: The filter tube comprises: At least two first pipe sections, the two first pipe sections are coaxially arranged and respectively connected to the tail pipe and the intake pipe, and threaded holes are formed at the ends of the two first pipe sections that are close to each other, and the threaded rotation directions of the two threaded holes are opposite; and at least one second pipe segment, two ends of the second pipe segment being respectively screwed to the two threaded holes; The filter element is installed in the second pipe section.

7. The fresh air circulation device of the clean room air conditioning system according to claim 1, characterized in that: A second sensor group is also provided at the main air outlet. The second sensor group is electrically connected to the circuit board assembly and is used to detect the exhaust humidity, temperature and dust concentration at the main air outlet.

8. The fresh air circulation device of the clean room air conditioning system according to claim 1, characterized in that: A fresh air circulation device of a clean workshop air conditioning system also includes an AHU air supply unit, the air inlet of the AHU air supply unit is connected to the air outlet of the FFU air supply unit, and the air outlet of the AHU air supply unit is used to communicate with the clean workshop.

9. A control method for a fresh air circulation device of a clean room air conditioning system, characterized in that: The control method is applied to the fresh air circulation device of the clean room air conditioning system according to any one of claims 1 to 8, comprising: Obtaining wind speed, temperature, humidity and dust concentration at the exhaust gas inlet; The communication states of the first electric valve, the second electric valve, and the third electric valve are controlled according to at least one of wind speed, temperature, humidity, and dust concentration.

10. A control method for a fresh air circulation device of a clean room air conditioning system according to claim 9, characterized in that: The pipeline structure further includes a filter tube, a filter element is arranged in the filter tube, one end of the filter tube is connected to the tail pipe, the other end is connected to the intake pipe, and the filter tube is arranged close to the sensor assembly; The plurality of electric valves further include a fourth electric valve disposed in the filter tube and between the filter element and the tailpipe, the fourth electric valve being electrically connected to the circuit board assembly; Controlling the connection state of the first electric valve, the second electric valve and the third electric valve according to at least one of wind speed, temperature, humidity and dust concentration includes: If the wind speed, temperature, humidity and dust concentration are all within the first set range, the first electric valve, the third electric valve and the fourth electric valve are controlled to be closed, and the second electric valve is opened; If at least one of the wind speed, temperature and dust concentration is outside a first set range, the first electric valve and the third electric valve are controlled to be opened, and the second electric valve and the fourth electric valve are controlled to be closed; If the wind speed, temperature, and dust concentration are all within the first setting range, and the humidity is outside the first setting range and within the second setting range, the first electric valve, the second electric valve, and the third electric valve are controlled to be closed, and the fourth electric valve is controlled to be opened.

Images