Fresh air return system of air conditioner

Abstract

A fresh air return system of an air conditioner comprises a simulation room, an air supply duct communicated with an air supply outlet of the simulation room, an air exhaust duct communicated with an air exhaust outlet of the simulation room and an air return duct communicated with the air supply duct and the air exhaust duct. A fresh air valve, a filter screen, a filter screen pressure difference switch, an ultraviolet lamp belt, a surface air cooler, an air feeder and an air feeding temperature and humidity sensor are sequentially mounted on the air feeding duct in the air feeding direction; an exhaust fan and an exhaust valve are sequentially mounted on the exhaust duct in the exhaust direction; the return air duct is provided with a return air valve and a return air temperature and humidity sensor; the simulation room is provided with an indoor temperature and humidity sensor, a carbon dioxide sensor, a PM2.5 sensor and an indoor pressure sensor; the fresh air valve, the exhaust valve, the return air valve, the air feeder, the exhaust fan, the filter screen differential pressure switch, the air feeding temperature and humidity sensor, the return air temperature and humidity sensor, the indoor temperature and humidity sensor, the carbon dioxide sensor, the PM2.5 sensor and the indoor pressure sensor are all electrically connected with a terminal strip of the electrical control box.

Description

TECHNICAL FIELD

[0001] The utility model belongs to equipment teaching technical field, especially related to a new air return system of air conditioner. BACKGROUND

[0002] In the theoretical teaching and practical teaching of the main courses such as Building Equipment Monitoring System, Building Water Supply and Drainage and Air Conditioning Engineering in the majors such as building electrical and intelligentization, building intelligentization engineering technology, the new air return system of air conditioner leads to less scene resources and poor teaching experience in the teaching process due to factors such as large equipment size and large floor area, cannot meet the students to intuitively and deeply understand the specific composition of the internal structure of the new air return system of air conditioner, and cannot enable the students to master the related professional technical knowledge through actual operation. UTILITY MODEL CONTENT

[0003] The utility model aims at providing a new air return system of air conditioner which is visual, strong in actual operation and convenient to install.

[0004] The technical solution of the utility model is a new air return system of air conditioner, including: a simulation room, a supply air duct connected with a supply air outlet of the simulation room, an exhaust air duct connected with an exhaust air outlet of the simulation room and an air return duct connected with the supply air duct and the exhaust air duct, the supply air duct is sequentially provided with a fresh air valve, a filter screen, a filter screen differential pressure switch, an ultraviolet lamp strip, a surface cooler, a supply fan and a supply air temperature and humidity sensor along a supply air direction, the exhaust air duct is sequentially provided with an exhaust fan and an exhaust valve along an exhaust air direction, the air return duct is provided with an air return valve and an air return temperature and humidity sensor, the simulation room is provided with an indoor temperature and humidity sensor, a carbon dioxide sensor, a PM2.5 sensor and an indoor pressure sensor, the fresh air valve, the exhaust valve, the air return valve, the supply fan, the exhaust fan, the filter screen differential pressure switch, the supply air temperature and humidity sensor, the air return temperature and humidity sensor, the indoor temperature and humidity sensor, the carbon dioxide sensor, the PM2.5 sensor and the indoor pressure sensor are electrically connected with a terminal block of an electrical control box.

[0005] Preferably, the electrical control box further includes a power supply and analog signal module, a supply fan and exhaust fan control module, the power supply and analog signal module is provided with a DC 24V and AC 24V weak current power supply for power supply, the supply fan and exhaust fan control module is provided with a rotary switch and a button for adjusting the supply fan and the exhaust fan.

[0006] Preferably, the electrical control box is electrically connected with a PLC controller or a DDC controller.

[0007] As preferred, the cabinet body further comprises a first horizontal pipe forming an exhaust air duct, a second horizontal pipe forming a return air duct, a third horizontal pipe forming a supply air duct, and a fourth horizontal pipe forming a simulation room, and the front vertical faces of the first, second, third and fourth horizontal pipes are transparent.

[0008] As preferred, a first fan plate for installing an exhaust fan is fixed at one end of the first horizontal pipe close to the fourth horizontal pipe, and an exhaust assembly for connecting an exhaust valve is fixed at the other end away from the fourth horizontal pipe; the exhaust assembly comprises a first inner horizontal beam fixed inside the first horizontal pipe, a first shaft pipe installed on the first inner horizontal beam and connected with the exhaust valve, a first vane plate fixed on the first shaft pipe, and first inner baffle plates fixed at opposite ends of the first inner horizontal beam, which are located at opposite sides of the first vane plate to limit the turning of the first vane plate.

[0009] As preferred, a return air assembly for connecting a return valve is fixed inside the second horizontal pipe; the return air assembly comprises a second inner horizontal beam fixed inside the second horizontal pipe, a second shaft pipe installed on the second inner horizontal beam and connected with the return valve, a second vane plate fixed on the second shaft pipe, and second inner baffle plates fixed at opposite ends of the second inner horizontal beam, which are located at opposite sides of the second vane plate to limit the turning of the second vane plate.

[0010] As preferred, the third horizontal pipe is sequentially fixed with an air inlet assembly for connecting a fresh air valve, a filter screen slot frame for installing a filter screen, a lamp strip support for installing an ultraviolet lamp strip, a surface cooling plate for installing a surface cooler, and a second fan plate for installing a supply fan in the supply air direction; the air inlet assembly comprises a third inner horizontal beam fixed inside the third horizontal pipe, a third shaft pipe installed on the third inner horizontal beam and connected with the fresh air valve, a third vane plate fixed on the third shaft pipe, and third inner baffle plates fixed at opposite ends of the third inner horizontal beam, which are located at opposite sides of the third vane plate to limit the turning of the third vane plate.

[0011] As preferred, four connecting members are symmetrically arranged at the bottom of the cabinet body, and the cabinet body can be fixed on a table top through the connecting members.

[0012] As preferred, four hanging ears are symmetrically arranged at the back vertical face of the cabinet body, and the cabinet body can be installed on a wall surface through the hanging ears.

[0013] Compared with the prior art, the cabinet has the following advantages:

[0014] 1. By constructing a simulated room, air supply duct, exhaust air duct and return air duct and installing corresponding equipment inside and on the surface thereof, the new return air operation principle and important components of an air conditioner are simulated, thereby providing an operation scene and experimental support for the theoretical and practical teaching of main courses such as Building Equipment Monitoring System, Building Electrical Control Technology, Building Water Supply and Drainage and Air Conditioning Engineering in the fields of building electrical and intelligentization, building intelligentization engineering technology and the like, so as to meet the needs of situational teaching and have good teaching experience.

[0015] 2. The system meets the needs of courses such as I / O point distribution, DDC / PLC programming, host computer configuration monitoring and the like, has strong practicality, and can effectively cultivate the professional technical ability of students in aspects such as point design, wiring, programming, integration, development, debugging, operation, maintenance and the like in cooperation with teaching.

[0016] 3. The system can make students intuitively and deeply understand the specific composition of the internal structure of the new return air system of an air conditioner, the installation position of equipment and the operation principle of the new return air system of an air conditioner.

[0017] 4. The system has small floor area, is convenient to put into experimental teaching use, and has various installation and fixing modes, can be hung on a wall surface through lugs, or can be fixed on a desktop through a connecting piece, so as to meet the use needs of different sites. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is a structural schematic view of the new return air system of an air conditioner of the utility model;

[0019] Figure 2 is a structural schematic view of a cabinet main body embodiment one of the utility model;

[0020] Figure 3 is a perspective view of Figure 2 ;

[0021] Figure 4 is an exploded view of Figure 3 ;

[0022] Figure 5 is a perspective view of a first horizontal pipe in Figure 3 ;

[0023] Figure 6 is a perspective view of a second horizontal pipe in Figure 3 ;

[0024] Figure 7 is a perspective view of a third horizontal pipe in Figure 3 ;

[0025] Figure 8 is a perspective view of a fourth horizontal pipe in Figure 3 ;

[0026] Figure 9 is the structural schematic view of the cabinet main body embodiment two of the utility model;

[0027] Figure 10 is the structural schematic view of the electrical control box of the utility model;

[0028] Figure 11 is the electrical connection schematic view of the air conditioner new return air system of the utility model.

[0029] Main component symbol explanation:

[0030] Cabinet main body 1;First horizontal pipe 11;Exhaust air duct 111;First fan plate 112;Exhaust air assembly 113;First inner crossbeam 1131;First shaft pipe 1132;First vane plate 1133;First inner baffle 1134;Second horizontal pipe 12;Return air duct 121;Return air assembly 122;Second inner crossbeam 1221;Second shaft pipe 1222;Second vane plate 1223;Second inner baffle 1224;Third horizontal pipe 13;Supply air duct 131;Air inlet assembly 132;Third inner crossbeam 1321;Third shaft pipe 1322;Third vane plate 1323;Third inner baffle 1324;Filter screen groove frame 133;Lamp strip support 134;Surface cooling plate 135;Second fan plate 136;Fourth horizontal pipe 14;Air supply port 141;Air exhaust port 142;Mounting plate 143;Acrylic plate 15;Mounting beam 16;Connecting piece 17;Lug 18;Fresh air valve 21;Exhaust air valve 22;Return air valve 23;Air supply fan 31;Exhaust fan 32;Supply air temperature and humidity sensor 41;Return air temperature and humidity sensor 42;Indoor temperature and humidity sensor 43;Carbon dioxide sensor 44;PM2.5 sensor 45;Indoor pressure sensor 46;Filter screen 5;Filter screen differential pressure switch 6;Ultraviolet lamp strip 7;Surface cooler 8;Electrical control box 9;Terminal strip 91;Power supply and analog signal module 92;Air supply fan and exhaust fan control module 93. DETAILED DESCRIPTION

[0031] The utility model will be further described in detail below in combination with the drawings:

[0032] Please refer to Figure 1As shown, the utility model provides a kind of air conditioning new return air system, it includes: simulation room, the air supply duct 131 being communicated with the air supply port 141 of simulation room, the exhaust air duct 111 being communicated with the air exhaust port 142 of simulation room and the return air duct 121 being communicated with air supply duct 131 and exhaust air duct 111, air supply duct 131 is installed with new air valve 21, filter screen 5, filter screen differential pressure switch 6, ultraviolet lamp strip 7, surface cooler 8, air supply fan 31 and air supply temperature and humidity sensor 41 in turn along air supply direction;Exhaust air duct 111 is installed with exhaust fan 32 and exhaust valve 22 in turn along air exhaust direction;Return air duct 121 is installed with return air valve 23 and return air temperature and humidity sensor 42;Simulation room is installed with indoor temperature and humidity sensor 43, carbon dioxide sensor 44, PM2.5 sensor 45 and indoor pressure sensor 46;New air valve 21, exhaust valve 22, return air valve 23, air supply fan 31, exhaust fan 32, filter screen differential pressure switch 6, air supply temperature and humidity sensor 41, return air temperature and humidity sensor 42, indoor temperature and humidity sensor 43, carbon dioxide sensor 44, PM2.5 sensor 45, indoor pressure sensor 46 are electrically connected with the terminal row 91 of electrical control box 9.

[0033] The air conditioning new return air system provided by the utility model simulates the operation principle and important components of air conditioning new return air by installing corresponding equipment inside and on the surface of simulation room, air supply duct, exhaust air duct and return air duct, so as to provide operation scene and experimental support for theoretical teaching and practical teaching of main courses such as Building Equipment Monitoring System, Building Electrical Control Technology, Building Water Supply and Drainage and Air Conditioning Engineering in the professional fields of building electrical and intelligentization, building intelligentization engineering technology and the like.

[0034] Please refer to Figure 10 、 Figure 11 As shown, electrical control box 9 is electrically connected with PLC controller or DDC controller, and further comprises power supply and analog signal module 92, air supply fan and exhaust fan control module 93; the power supply and analog signal module 92 is provided with DC 24V and AC 24V weak current power supply for power supply; and the air supply fan and exhaust fan control module 93 is provided with rotary switch and button for adjusting air supply fan and exhaust fan.

[0035] Specifically, as Figure 11As shown, the terminal of the fresh air valve 21, the exhaust air valve 22, the return air valve 23, the air supply fan 31, the exhaust fan 32, the filter screen differential pressure switch 6, the air supply temperature and humidity sensor 41, the return air temperature and humidity sensor 42, the indoor temperature and humidity sensor 43, the carbon dioxide sensor 44, the PM2.5 sensor 45 and the indoor pressure sensor 46 are connected in parallel to the terminal row 91 of the electrical control box 9, and the terminal row 91 is electrically connected to the PLC controller or the DDC controller outside the electrical control box 9, for the operation control and the upper computer configuration monitoring of the system; the electrical control box 9 provides DC 24V and AC 24V weak current power supply for powering the equipment. The air conditioning fresh air return system provided by the utility model provides point design, logic control, upper computer configuration monitoring and the like of the air conditioning fresh air return system, and trains the professional technical ability of students in point design, wiring, programming, integration, development, debugging, operation, maintenance and the like.

[0036] The air conditioning fresh air return system can realize automatic operation or manual operation. In the automatic state, all the sensor signals / air valve signals / fan signals and the like are connected to the PLC or the DDC controller, and the controller detects the data of each equipment and controls each air valve and fan in real time; when the indoor temperature is greater than the air supply temperature, the controller controls the fresh air valve to be opened and the air supply fan to be opened; when the indoor temperature is equal to the air supply temperature, the fresh air valve opening degree is reduced, the return air valve is opened, and the exhaust air valve is closed, so that the air is circulated; the filter screen differential pressure switch checks the pressure difference before and after the filter screen, and when the pressure difference is large, it indicates that the filter screen needs to be cleaned, and when the filter screen differential pressure switch is triggered, the upper computer configuration sends an alarm information to remind timely cleaning; when the indoor carbon dioxide sensor exceeds the set value, the fresh air valve and the exhaust air valve are opened, and the return air valve is closed; then the air supply fan and the exhaust fan are opened, and the indoor air is quickly replaced. In the manual state, the air valve drive can be manually opened, the state of the air supply fan and the exhaust fan on the electrical control box is set to manual, and the air supply fan and the exhaust fan can be started and stopped by pressing the button.

[0037] Please refer to Figures 2 to 4 As shown, the air conditioning fresh air return system further comprises a cabinet main body 1, the cabinet main body 1 comprises a first horizontal pipe 11 forming an exhaust air duct 111, a second horizontal pipe 12 forming a return air duct 121, a third horizontal pipe 13 forming an air supply duct 131 and a fourth horizontal pipe 14 forming a simulated room 141, and the front vertical surface of the first horizontal pipe 11, the second horizontal pipe 12, the third horizontal pipe 13 and the fourth horizontal pipe 14 are all transparent structures; in this embodiment, as shown in the figure, Figure 4 As shown, the front vertical surface of the first horizontal pipe 11, the second horizontal pipe 12, the third horizontal pipe 13 and the fourth horizontal pipe 14 are all installed with acrylic plates 15, so as to observe the internal structure. Two mounting beams 16 are fixed between the first horizontal pipe 11 and the third horizontal pipe 13, for mounting the electrical control box 9.

[0038] In this embodiment, the cabinet body 1 is installed in a split type, the main material is cold-pressed plate and acrylic, which can meet the equipment installation and show the equipment installation position and operation condition.

[0039] Please refer to Figure 5 As shown in the drawings, the first fan plate 112 for installing the exhaust fan 32 is fixed at one end of the first horizontal pipe 11 close to the fourth horizontal pipe 14, and the exhaust assembly 113 for connecting the exhaust valve 22 is fixed at the other end away from the fourth horizontal pipe 14. The exhaust assembly 113 includes the first inner cross beam 1131 fixed inside the first horizontal pipe 11, the first shaft pipe 1132 installed on the first inner cross beam 1131 and connected with the exhaust valve 22, the first vane plate 1133 fixed on the first shaft pipe 1132, and the first inner baffle 1134 fixed at the opposite ends of the first inner cross beam 1131, which is located at the opposite sides of the first vane plate 1133 to limit the turning of the first vane plate 1133.

[0040] Specifically, as shown in the drawings, Figure 1 , Figure 5 The exhaust assembly 113 is located at the exhaust outlet position of the first horizontal pipe 11 away from the fourth horizontal pipe 14, the first inner cross beam 1131 is welded at the top and bottom inside the first horizontal pipe 11, the first shaft pipe 1132 passes through the hole between the two first inner cross beams 1131 from the bottom of the first horizontal pipe 11, the first vane plate 1133 is fixed on the first shaft pipe 1132 by screws, and the first inner baffle 1134 is welded between the front and back of the two first inner cross beams 1131. Since the first inner baffle 1134 is located at the opposite sides of the first vane plate 1133, the first shaft pipe 1132 can only rotate 90 degrees when rotating, which meets the rotation angle of the exhaust valve 22. The rotation hole of the exhaust valve 22 is connected with the part of the first shaft pipe 1132 extending out of the bottom of the first horizontal pipe 11, and the exhaust valve 22 is installed on the outer surface of the bottom of the first horizontal pipe 11. When the exhaust valve 22 operates, it drives the first shaft pipe 1132 to rotate, and the first vane plate 1133 also rotates. By rotating the first shaft pipe 1132 to adjust the first vane plate 1133 through the exhaust valve 22, the on-off and size control of the exhaust air volume can be realized.

[0041] Please refer to Figure 6 As shown in the drawings, the second exhaust assembly 122 for connecting the return valve 23 is fixed in the second horizontal pipe 12. The second exhaust assembly 122 includes the second inner cross beam 1221 fixed inside the second horizontal pipe 12, the second shaft pipe 1222 installed on the second inner cross beam 1221 and connected with the return valve 23, the second vane plate 1223 fixed on the second shaft pipe 1222, and the second inner baffle 1224 fixed at the opposite ends of the second inner cross beam 1221, which is located at the opposite sides of the second vane plate 1223 to limit the turning of the second vane plate 1223.

[0042] Specifically, as shown in Figure 1 , Figure 6 the second inner cross beams 1221 are welded on the left and right sides inside the second cross pipe 12, the second shaft pipe 1222 passes through the hollow space between the two second inner cross beams 1221 from one side of the second cross pipe 12, the second vane plate 1223 is fixed on the second shaft pipe 1222 by screws, and the second inner baffle 1224 is welded between the front and back of the two second inner cross beams 1221. Since the second inner baffle 1224 is located on the opposite sides of the second vane plate 1223, the second shaft pipe 1222 can only rotate 90 degrees when rotating, which meets the rotation angle of the return air valve 23. The rotation hole of the return air valve 23 is connected with the part of the second shaft pipe 1222 extending out of the side surface of the second cross pipe 12, the return air valve 23 is installed on the side surface of the second cross pipe 12, and when the return air valve 23 operates, it drives the second shaft pipe 1222 to rotate, and the second vane plate 1223 also rotates. By rotating the second shaft pipe 1222 to adjust the second vane plate 1223 through the return air valve 23, the on-off and size control of the return air volume can be realized.

[0043] Please refer to Figure 7 , the third cross pipe 13 has, in sequence from the air supply direction, an air inlet assembly 132 for connecting the fresh air valve 21, a filter screen groove frame 133 for installing the filter screen 5, a lamp strip support 134 for installing the ultraviolet lamp strip 7, a surface cooling plate 135 for installing the surface cooler 8, and a second fan plate 136 for installing the air supply fan 31; wherein the air inlet assembly 132 includes third inner cross beams 1321 fixed inside the third cross pipe 13, a third shaft pipe 1322 installed on the third inner cross beams 1321 and connected with the fresh air valve 21, a third vane plate 1323 fixed on the third shaft pipe 1322, and third inner baffles 1324 fixed on the opposite ends of the third inner cross beams 1321. The third inner baffles 1324 are located on the opposite sides of the third vane plate 1323 to limit the overturning of the third vane plate 1323.

[0044] Specifically, as shown in Figure 1 , Figure 7As shown, the air inlet assembly 132 is in the fresh air inlet position at the end of the third cross pipe 13 away from the fourth cross pipe 14, the third inner cross beam 1321 is welded at the top and bottom inside the third cross pipe 13, the third shaft pipe 1322 passes through the hole between the two third inner cross beams 1321 from the top of the third cross pipe 13, the third vane plate 1323 is fixed on the third shaft pipe 1322 by screws, and the third inner baffle 1324 is welded between the front and back of the two third inner cross beams 1321. Since the third inner baffle 1324 is located on the opposite sides of the third vane plate 1323, the third shaft pipe 1322 can only rotate 90 degrees when rotating, which meets the rotation angle of the fresh air valve 21. The rotation hole of the fresh air valve 21 is connected with the part of the third shaft pipe 1322 extending out of the top of the third cross pipe 13, and the fresh air valve 21 is installed on the outer surface of the top of the third cross pipe 13. When the fresh air valve 21 is actuated, the third shaft pipe 1322 is rotated, and the third vane plate 1323 is also rotated. The third vane plate 1323 is adjusted by rotating the third shaft pipe 1322 through the fresh air valve 21, so that the fresh air volume on-off and size control can be realized.

[0045] As shown in Figure 8 As shown, the fourth cross pipe 14 is provided with a supply air port 141 at one end, and the third cross pipe 13 is communicated with the fourth cross pipe 14 through the supply air port 141 to supply air to the simulated room; the fourth cross pipe 14 is provided with an exhaust air port 142 at the other end, and the first cross pipe 11 is communicated with the fourth cross pipe 14 through the exhaust air port 142 to facilitate the exhaust of the simulated room; and the fourth cross pipe 14 is further fixed with a mounting plate 143 for mounting the indoor temperature and humidity sensor 43, the carbon dioxide sensor 44, the PM2.5 sensor 45 and the indoor pressure sensor 46.

[0046] In an embodiment, as shown in Figure 2 、 Figure 3 As shown, the cabinet body 1 is provided with four connecting pieces 17 at the bottom symmetrically, and the cabinet body 1 can be fixed on the desktop through the connecting pieces 17.

[0047] In another embodiment, as shown in Figure 9 As shown, the cabinet body 1 is provided with four hanging ears 18 on the back vertical surface symmetrically, and the cabinet body 1 can be installed on the wall surface through the hanging ears 18.

[0048] The working principle of the air conditioner fresh air return system provided by the utility model is as follows:

[0049] As shown in Figure 1As shown, the fresh air enters the supply air duct 131 through the fresh air valve 21, the fresh air and the return air are mixed, filtered through the filter screen 5, disinfected and sterilized by the ultraviolet lamp strip 7, and pass through the supply air temperature and humidity sensor 41 to measure the temperature and humidity of the supply air, and are sent into the simulation room through the supply air outlet 141 by the supply air fan 31. The simulation room is provided with the indoor temperature and humidity sensor 43, the carbon dioxide sensor 44, the PM2.5 sensor 45 and the indoor pressure sensor 46, the simulation room discharges air through the exhaust air outlet 142 to the exhaust air duct 111, and after passing through the exhaust air fan 32, part of the air is discharged through the exhaust air valve 22, and the other part is mixed with the fresh air through the return air valve 23 and enters the next cycle, and the return air valve 23 is provided with the return air temperature and humidity sensor 42 to detect the temperature and humidity of the return air.

[0050] The above is only the preferred embodiment of the present application, and any change and modification made within the scope of the present application should be included in the scope of the present application.

Claims

1. An air conditioning fresh air return system, characterized by, The application relates to a simulation room air conditioning system, which comprises the following parts: a simulation room, an air supply air duct connected with the air supply outlet of the simulation room, an air exhaust air duct connected with the air exhaust outlet of the simulation room, and an air return air duct connected with the air supply air duct and the air exhaust air duct, wherein the air supply air duct is sequentially provided with a fresh air valve, a filter screen, a filter screen differential pressure switch, an ultraviolet lamp belt, a surface cooler, an air supply fan and an air supply temperature and humidity sensor along an air supply direction; the air exhaust air duct is sequentially provided with an air exhaust fan and an air exhaust valve along an air exhaust direction; the air return air duct is provided with an air return valve and an air return temperature and humidity sensor; the simulation room is provided with an indoor temperature and humidity sensor, a carbon dioxide sensor, a PM2.5 sensor and an indoor pressure sensor; the fresh air valve, the air exhaust valve, the air return valve, the air supply fan, the air exhaust fan, the filter screen differential pressure switch, the air supply temperature and humidity sensor, the air return temperature and humidity sensor, the indoor temperature and humidity sensor, the carbon dioxide sensor, the PM2.5 sensor and the indoor pressure sensor are electrically connected with a terminal row of an electrical control box. The electrical control box further comprises a power supply and simulation signal module, an air supply fan and air exhaust fan control module, the power supply and simulation signal module is provided with DC24V and AC24V weak current power sources for power supply, and the air supply fan and air exhaust fan control module is provided with a rotary switch and a button for adjusting the air supply fan and the air exhaust fan.

2. The new air return system of claim 1, wherein, The electrical control box is electrically connected with a PLC controller or a DDC controller.

3. The new air return system of claim 2, wherein, The application further relates to a cabinet main body, which comprises a first horizontal pipe forming an air exhaust air duct, a second horizontal pipe forming an air return air duct, a third horizontal pipe forming an air supply air duct and a fourth horizontal pipe forming a simulation room, wherein the front vertical surfaces of the first horizontal pipe, the second horizontal pipe, the third horizontal pipe and the fourth horizontal pipe are transparent structures; two mounting beams are fixed between the first horizontal pipe and the third horizontal pipe and used for mounting the electrical control box.

4. The air conditioning fresh air return system of any one of claims 1-3, wherein, A first fan plate for mounting the air exhaust fan is fixed at one end of the first horizontal pipe close to the fourth horizontal pipe, and an air exhaust assembly for connecting the air exhaust valve is fixed at the other end away from the fourth horizontal pipe; 5. The new air return system of claim 4, wherein, The air exhaust assembly comprises a first inner horizontal beam fixed in the first horizontal pipe, a first shaft pipe mounted on the first inner horizontal beam and connected with the air exhaust valve, a first vane plate fixed on the first shaft pipe, and first inner baffles fixed at opposite ends of the first inner horizontal beam, wherein the first inner baffles are located at opposite sides of the first vane plate to limit the turning of the first vane plate. An air return assembly for connecting the air return valve is fixed in the second horizontal pipe; 6. The new air return system of claim 4, wherein, The air return assembly comprises a second inner horizontal beam fixed in the second horizontal pipe, a second shaft pipe mounted on the second inner horizontal beam and connected with the air return valve, a second vane plate fixed on the second shaft pipe, and second inner baffles fixed at opposite ends of the second inner horizontal beam, wherein the second inner baffles are located at opposite sides of the second vane plate to limit the turning of the second vane plate. The third horizontal pipe is sequentially provided with an air inlet assembly for connecting the fresh air valve, a filter screen slot frame for mounting the filter screen, a lamp belt support for mounting the ultraviolet lamp belt, a surface cooler plate for mounting the surface cooler and a second fan plate for mounting the air supply fan along the air supply direction; 7. The new air return system of claim 4, wherein, ​ The air inlet assembly comprises a third inner cross beam fixed inside a third cross pipe, a third shaft pipe mounted on the third inner cross beam and connected with the fresh air valve, a third vane plate fixed on the third shaft pipe, and third inner baffle plates fixed on opposite ends of the third inner cross beam, the third inner baffle plates being located on opposite sides of the third vane plate to limit turning of the third vane plate.

8. The new air return system of claim 4, wherein, The cabinet body is symmetrically provided with four connecting pieces at the bottom, and the cabinet body can be fixed on a desktop through the connecting pieces.

9. The new air return system of claim 4, wherein, The cabinet body is symmetrically provided with four hanging ears on the back vertical surface, and the cabinet body can be installed on a wall surface through the hanging ears.

Images