Fan coil unit of energy-saving air conditioning system

Abstract

The invention relates to the technical field of air conditioning equipment, and particularly discloses an energy-saving air conditioning system fan coil unit which mainly comprises a machine shell, a surface air cooler, a centrifugal fan and a driving motor. A filter cartridge is assembled at an air inlet of the volute, one end of the filter cartridge is connected with the periphery of the air inlet, the other end of the filter cartridge extends into the centrifugal impeller, and a filter area is arranged at the side part; a rotary arm is connected to an output shaft of the driving motor, a one-way transmission mechanism is arranged between the rotary arm and the driving motor, and a spiral scraper attached to the inner wall of the filter drum is fixedly arranged on the rotary arm. When the unit is in normal air supply operation, air is filtered through the filter cartridge, air streaming is avoided, a good filtering effect is achieved, dust accumulation of core components is reduced, the heat exchange and air supply efficiency of the unit is guaranteed, and energy conservation and noise reduction are achieved. And when the driving motor reversely runs, the spiral scraping blade scrapes off foreign matters adhered to the inner wall of the filter cartridge and drives the foreign matters to be discharged, so that the filter cartridge is automatically cleaned, the high efficiency of air filtration is guaranteed, and the operation and maintenance cost is greatly reduced.

Description

Technical Field

[0001] This invention relates to the field of air conditioning equipment technology, and in particular to an energy-saving air conditioning system fan coil unit. Background Technology

[0002] As a core terminal device in a central air conditioning system, the fan coil unit uses a fan to drive airflow and exchange heat with a surface cooler to achieve precise control of indoor temperature and humidity. Its operating efficiency and stability directly determine the overall energy consumption and performance of the central air conditioning system. During operation, outside air continuously enters the internal air duct. Dust, hair, lint, and other foreign matter in the air, if not filtered and directly contacting core components such as the centrifugal impeller and surface cooler, can easily accumulate on the surface of these components, leading to a series of operational malfunctions: Dust accumulation on the centrifugal impeller disrupts its dynamic balance, causing a sharp increase in unit operating noise and a significant decrease in fan efficiency, resulting in increased ineffective energy consumption; dust accumulation on the surface cooler clogs the fin gaps, reducing the heat exchange efficiency between gas and liquid. To achieve the set temperature and humidity, the unit needs to operate at high load for extended periods, further exacerbating energy consumption. Therefore, air filtration components are an essential feature of fan coil units, used to purify the air entering the unit and prevent foreign matter from entering the core component areas.

[0003] In existing technologies, to facilitate routine disassembly, cleaning, and maintenance of air filter components, the industry generally places them at the return air vent of fan coil units. However, in actual engineering applications, fan coil units are mostly installed concealed, with their return air vents typically located in the building ceiling. The area above the ceiling is an unsealed space with airflow channels, allowing outside air to easily bypass the filter and enter the unit's internal ductwork, significantly reducing the filtration effect. This problem directly results in continuous dust accumulation on core components such as the centrifugal impeller and surface cooler, not only keeping the unit's heat exchange and air delivery efficiency at a consistently low level, reducing the overall energy efficiency and stability of the central air conditioning system, but also requiring frequent professional cleaning and maintenance of the unit's interior, significantly increasing the system's operating and maintenance costs. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides an energy-saving air conditioning system fan coil unit, aiming to solve the technical problem that poor filtration in existing fan coil units leads to easy dust accumulation in core components, resulting in poor energy efficiency and low maintenance economy.

[0005] To achieve the above technical objectives, the present invention adopts the following technical solution: An energy-saving air conditioning system fan coil unit includes a casing, a surface cooler, a centrifugal fan, and a drive motor. The centrifugal fan consists of a volute and a centrifugal impeller. A filter cartridge is installed at the air inlet of the volute. One end of the filter cartridge is open and sealed to the outer periphery of the air inlet. The other end of the filter cartridge has a bottom that extends into the hollow area of ​​the centrifugal impeller. A central hole is provided at the bottom. The drive motor is a bidirectional output motor. The output shaft passes through the central hole. A rotary arm is rotatably connected to the output shaft, and a one-way transmission mechanism is provided between the two. Several spiral scrapers are fixedly connected to the rotary arm. The sides of the spiral scrapers are attached to the inner wall of the filter cartridge and extend spirally along the axial direction of the filter cartridge. When the output shaft rotates in one direction, the one-way transmission mechanism is in a disengaged state during normal air supply operation of the fan coil unit. When the output shaft rotates in the other direction, the rotary arm is driven to rotate by the one-way transmission mechanism, and the spiral scrapers scrape off foreign objects adhering to the inner wall of the filter cartridge and discharge the scraped foreign objects to the outside of the filter cartridge.

[0006] In a preferred embodiment, a cleaning component is fixedly connected to the side of the spiral scraper that is in contact with the inner wall of the filter cartridge; the cleaning component is a flexible structure such as flexible bristles or cleaning cotton.

[0007] In a preferred embodiment, the one-way transmission mechanism is a one-way bearing.

[0008] In a preferred embodiment, the outer periphery of the open end of the filter cartridge is provided with an outwardly flared sealing edge, and the sealing edge is fixedly connected to the outer periphery of the air inlet by bolts or clips.

[0009] In a preferred embodiment, a bushing is fixedly installed on the central hole at the bottom of the filter cartridge, and the output shaft of the drive motor is rotatably engaged with the bushing.

[0010] In a preferred embodiment, there are two centrifugal fans arranged coaxially and spaced apart on the casing, with the rotation axes of the centrifugal impellers of the two centrifugal fans coinciding; the drive motor is mounted between the two centrifugal fans, and the drive motor is a special dual-shaft output motor for fan coil units, with the two output shafts fixedly connected to the centrifugal impellers on the corresponding sides.

[0011] In a preferred embodiment, the centrifugal impeller consists of a disc, several blades, and two end rings. The disc is fixedly connected to the output shaft, and the two end rings are distributed on both sides of the disc along the axial direction. The blades extend axially, with the middle part of the blades fixedly connected to the outer circle of the disc, and the two ends of the blades fixedly connected to the end rings respectively. Air inlets are provided on both opposite side walls of the volute to adapt to the bidirectional air intake structure of the centrifugal impeller.

[0012] In a preferred embodiment, a dust collection hopper is fixedly provided on the lower side of the volute, and the air inlet of the volute is located in the area above the dust collection hopper. When the spiral scraper cleans the filter cartridge, the discharged foreign matter falls directly into the dust collection hopper for collection.

[0013] In a preferred embodiment, the output shaft sidewall is provided with a plurality of water spray holes, which are located in the internal area of ​​the filter cartridge; the output shaft is provided with a flow channel communicating with each water spray hole; a rotary joint is rotatably connected to the output shaft, the rotary joint is connected to the flow channel, a water supply unit is connected to the outside of the rotary joint, and a drain pipe is connected to the lower end of the volute.

[0014] Furthermore, the water supply unit consists of a water pump, a collection bottle, and a water delivery pipe; the rotary joint is connected to the output end of the water pump, the input end of the water pump is connected to the collection bottle via the water delivery pipe, and the collection bottle is connected to the condensate pipe via a multi-port connector. Even further, a filter screen is installed at the inlet end of the collection bottle, and the water inlet of the water delivery pipe is located on the lower side wall of the collection bottle.

[0015] In a preferred embodiment, an extension tube is fixedly connected to the end of the output shaft away from the drive motor. The end of the extension tube away from the output shaft is a blind end. Several water spray holes are opened on the side wall of the extension tube, and the inner cavity of the extension tube is connected to the flow channel of the output shaft.

[0016] Compared with the prior art, the energy-saving air conditioning system fan coil unit of the present invention has the following beneficial technical effects: 1. The filter cartridge is sealed at the air inlet of the volute, completely eliminating the problem of air bypassing and entering the unit. It effectively blocks dust, hair and other foreign objects from contacting the centrifugal impeller, surface cooler and other core components, ensuring the dynamic balance characteristics of the centrifugal impeller and the heat exchange efficiency of the surface cooler. It avoids the problem of reduced air supply efficiency and reduced heat exchange effect caused by dust accumulation on the components, thereby reducing the ineffective energy consumption of the unit under high load from the root and achieving significant energy saving and noise reduction effects.

[0017] 2. Through the coordinated design of a bidirectional output motor, a unidirectional transmission mechanism, and a spiral scraper, the system achieves seamless switching between filter cartridge cleaning and normal unit operation. During normal airflow operation, the rotating arm and spiral scraper remain stationary with no additional power consumption. Automatic cleaning of the filter cartridge is achieved through the reverse low-speed rotation of the drive motor, resulting in excellent cleaning performance and effectively maintaining the long-term filtration efficiency of the filter cartridge. No manual operation is required, leading to low maintenance costs.

[0018] 3. The filter cartridge adopts a side-filtration design, which has a larger effective filtration area compared to traditional flat filters. While ensuring filtration effect, it significantly reduces airflow resistance and greatly improves the unit's ventilation efficiency. The filter cartridge adopts an internal installation structure, and the external shape and outline dimensions of the unit can completely follow the design standards of traditional fan coil units. It can be directly adapted to existing conventional installation accessories and installation environments, without the need for additional modifications to the building's return air layout or unit supporting components. This greatly reduces the engineering implementation difficulty of the product and enhances the practical promotion value of the technical solution. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings of the embodiments will be briefly described below. Obviously, the drawings described below only relate to some embodiments of the present invention and are not intended to limit the present invention.

[0020] Figure 1 This is a schematic diagram of the front structure of the fan coil unit in the embodiment.

[0021] Figure 2 This is a schematic diagram of the structure at the rear of the fan coil unit in the embodiment.

[0022] Figure 3 This is a schematic diagram of the centrifugal fan after partial cross-section in the embodiment.

[0023] Figure 4 This is a schematic diagram showing the disassembly of the centrifugal fan components in the embodiment.

[0024] Figure 5 This is a schematic diagram of the assembly structure of components such as the centrifugal impeller, output shaft, filter cartridge, and spiral scraper in the embodiment.

[0025] Figure 6 This is a schematic diagram of the structure of the rotary arm and the spiral scraper in the embodiment.

[0026] Figure 7 This is a schematic diagram showing the coordinated state of the rotary arm, spiral scraper, and filter cartridge in the embodiment.

[0027] Figure 8 This is a schematic diagram showing the configuration of the ash hopper in the embodiment.

[0028] Figure 9 This is a schematic diagram showing the coordinated state of the output shaft, rotary joint, water pump device, and liquid collection bottle in the embodiment.

[0029] Figure 10 This is a schematic diagram of the connection structure between the output shaft and the extension tube in the embodiment.

[0030] Figure label: 1-Centrifugal fan; 101-Volume; 102-Centrifugal impeller; 1021-Blade; 1022-Disc; 1023-End ring; 2-Drive motor; 201-Output shaft; 202-Water spray hole; 203-Extension pipe; 3-Casing; 301-Air outlet; 4-Filter cartridge; 401-Sealing edge; 402-Center hole; 403-Bottom; 5-Condensate tray; 6-Surface cooler; 7-Spiral scraper; 8-Rotating arm; 9-One-way transmission mechanism; 10-Ash hopper; 11-Rotary joint; 12-Water pump device; 13-Water delivery pipe; 14-Drain pipe; 15-Collection bottle; 16-Multi-port connector. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0032] Reference Figures 1-7 As shown, this embodiment of the invention provides an energy-saving air conditioning system fan coil unit, including a casing 3, a surface cooler 6, a centrifugal fan 1, a drive motor 2, and a condensate tray 5, among other main components. The casing 3 is a sheet metal structure with an air outlet 301 on its side. The surface cooler 6 is a copper tube aluminum fin heat exchanger structure, installed in the air duct path inside the casing 3. The centrifugal fan 1 adopts a multi-blade centrifugal fan structure, consisting of a volute 101 and a centrifugal impeller 102 that are mutually adapted. The volute 101 is sealed and fixedly connected to the casing 3, and an air inlet is provided on the side wall of the volute 101. The centrifugal impeller 102 includes a disc 1022 and multiple blades 1021. The disc 1022 is coaxially and fixedly connected to the output shaft 201 of the drive motor 2. The blades 1021 extend axially and are fixed at equal angles on the outer circle of the disc 1022. The condensate tray 5 is fixedly installed on the lower side of the casing 3 to receive and collect condensate generated during the operation of the unit.

[0033] The energy-saving air conditioning system fan coil unit is equipped with a filter cartridge 4 at the air inlet of the volute 101. One end of the filter cartridge 4 is an open structure, and the outer periphery of this end is provided with an outwardly flared sealing edge 401. The other end of the filter cartridge 4 is a closed bottom 403. A central hole 402 is opened at the center of the bottom 403. The filtration area is located on the side of the filter cartridge 4. The filter cartridge 4 extends into the hollow area of ​​the centrifugal impeller 102 through the air inlet with one end of the bottom 403 facing the inside of the volute 101. Its sealing edge 401 is sealed and fixed to the outer periphery of the air inlet by bolts or buckles, ensuring that air can only enter the inside of the volute 101 through the filtration area on the side of the filter cartridge 4.

[0034] The drive motor 2 of the fan coil unit of this energy-saving air conditioning system is a bidirectional output motor that can rotate in both directions. Its direction of rotation is controlled by the central air conditioning control system. The output shaft 201 of the drive motor 2 passes through the central hole 402 of the bottom 403 of the filter cartridge 4. A rotary arm 8 is mounted on the output shaft 201 and is perpendicular to it. The output shaft 201 and the rotary arm 8 are rotatably connected, and a one-way transmission mechanism 9 is set between them to realize the one-way transmission of torque. The rotary arm 8 is located inside the filter cartridge 4. Several spiral scrapers 7 are fixedly connected to the rotary arm 8. The side of the spiral scraper 7 is attached to the inner wall of the filter cartridge 4 and extends spirally along the axial direction of the filter cartridge 4.

[0035] When the output shaft 201 of the drive motor 2 rotates in the first direction, it drives the centrifugal impeller 102 to rotate synchronously, realizing the normal air supply operation of the unit. At this time, the outside air enters the volute 101 after being filtered by the side filter area of ​​the filter cartridge 4, effectively blocking dust, hair and other foreign objects from entering the unit, ensuring the dynamic balance and conveying efficiency of the centrifugal impeller 102 and the heat exchange efficiency of the surface cooler 6, while maintaining the overall unobstructed air duct, and realizing the energy-saving and noise reduction effect of the unit. In this operating state, the one-way transmission mechanism 9 is in the separated state, and the rotary arm 8 and the spiral scraper 7 remain stationary to avoid generating additional power consumption.

[0036] When the output shaft 201 of the drive motor 2 rotates at low speed in the second direction, the one-way transmission mechanism 9 is engaged. The output shaft 201 drives the rotary arm 8 to rotate synchronously at low speed through the one-way transmission mechanism 9, causing the spiral scraper 7 to rotate against the inner wall of the filter cartridge 4, scraping off the foreign matter adhering to the inner wall of the filter cartridge 4. With the help of the axial conveying characteristics of the spiral scraper 7, the scraped foreign matter is continuously pushed to the open end of the filter cartridge 4 and finally discharged to the outside of the filter cartridge 4, realizing the automatic cleaning of the filter cartridge 4, effectively maintaining the filtration efficiency of the filter cartridge 4, and greatly reducing the difficulty and cost of manual maintenance.

[0037] In this energy-saving air conditioning system fan coil unit, the filter cartridge 4 adopts a built-in installation structure. The external shape and outline dimensions of the unit can completely follow the design standards of traditional fan coil units, and it can be directly adapted to existing conventional installation accessories without requiring additional modifications to the installation environment and supporting components, greatly improving the ease of implementation in practical applications. At the same time, by placing the filtration area on the side of the filter cartridge 4, compared to installing a flat filter screen directly at the air inlet of the volute 101, the side-filtered filter cartridge 4 has a larger effective filtration area. While fully ensuring the air filtration effect and preventing the entry of foreign objects, it can significantly reduce airflow resistance and effectively improve the ventilation efficiency of the unit.

[0038] The spiral scraper 7 of this energy-saving air conditioning system's fan coil unit adopts a spiral structure design, which not only improves the contact effect between the spiral scraper 7 and the inner wall of the filter cartridge 4, but also enables the spiral scraper 7 to have an axial conveying function, which can discharge scraped foreign objects to the outside of the filter cartridge 4. In addition, the spiral structure gives the spiral scraper 7 excellent elastic deformation performance, allowing it to adaptively fine-tune the contact state when in contact with the inner wall of the filter cartridge 4, effectively avoiding rigid contact with the filter cartridge 4 during cleaning, greatly reducing mutual wear between the filter cartridge 4 and the scraper, and extending the service life of both.

[0039] In a further embodiment, a cleaning component is fixedly connected to the side of the spiral scraper 7 that is in contact with the inner wall of the filter cartridge 4. The cleaning component can be a flexible structure such as flexible bristles or cleaning cotton. This improves the cleaning effect on foreign matter adhering to the inner wall of the filter cartridge 4 and effectively buffers the contact force between the scraper and the filter cartridge 4, reducing physical scratch damage to the inner wall of the filter cartridge 4.

[0040] In a specific implementation, the one-way transmission mechanism 9 is used to realize the one-way transmission of torque. It can be implemented using existing mature transmission structures. Specifically, one-way bearings can be selected, or the one-way transmission mechanism 9 of a bicycle flywheel can be adapted and designed. Both can realize the one-way transmission requirement between the output shaft 201 and the rotary arm 8.

[0041] In a further embodiment, a bushing can be fixedly installed on the center hole 402 of the bottom 403 of the filter cartridge 4, and the output shaft 201 of the drive motor 2 is rotatably engaged with the bushing. This structural design provides radial support to the filter cartridge 4 through the output shaft 201, effectively preventing the filter cartridge 4 from shaking or shifting during unit operation and ensuring the fitting accuracy between the filter cartridge 4 and the spiral scraper 7. On the other hand, it can improve the sealing performance of the mating position between the filter cartridge 4 and the output shaft 201, preventing air from directly entering the volute 101 around the filtration area of ​​the filter cartridge 4, thus ensuring the effectiveness of air filtration.

[0042] In a further embodiment, the fan coil unit of this energy-saving air conditioning system adopts a dual-fan design, with the specific structure as follows: like Figures 1-3 As shown, two centrifugal fans 1 are provided, arranged coaxially and fixed to the casing 3. The rotation axes of the centrifugal impellers 102 of the two centrifugal fans 1 are kept coincident. The drive motor 2 is mounted between the two centrifugal fans 1. The drive motor 2 is a fan coil unit-specific dual-shaft output motor, and the two output shafts 201 are respectively fixedly connected to the impeller discs 1022 of the corresponding centrifugal impellers 102. The dual-fan design can significantly improve the overall air volume and air pressure of the unit, effectively improving the heat exchange and ventilation efficiency of the unit.

[0043] In a further embodiment, the centrifugal fan 1 of the fan coil unit of this energy-saving air conditioning system adopts a bidirectional air intake design, and its specific structure is as follows: like Figure 3 , Figure 4 , Figure 5As shown, the centrifugal impeller 102 consists of a disc 1022, several blades 1021, and two end rings 1023. The disc 1022 is fixedly connected to the output shaft 201 of the drive motor 2. The two end rings 1023 are symmetrically distributed on both axial sides of the disc 1022, and the disc 1022 and the two end rings 1023 are concentrically arranged. The blades 1021 extend axially, with the middle part of the blade 1021 fixedly connected to the outer circle of the disc 1022, and the two ends of the blade 1021 fixedly connected to the two end rings 1023, thereby enabling the centrifugal impeller 102 to have a bidirectional air intake function. The volute 101 has symmetrical air inlets on its opposite side walls, which are adapted to the bidirectional air intake structure of the centrifugal impeller 102. When the centrifugal impeller 102 rotates, the two air inlets of the volute 101 can simultaneously draw in air, greatly increasing the air intake volume per unit time, thereby effectively improving the ventilation efficiency of the unit. Corresponding to the dual air inlet design of the volute 101, two sets of filtration and cleaning components, such as filter cartridge 4, rotating arm 8 and spiral scraper 7, are also provided, each corresponding to one of the two air inlets, to ensure the filtration and automatic cleaning effect of bidirectional air intake.

[0044] In a further implementation, such as Figure 8 As shown, a dust collection hopper 10 is fixedly installed on the lower side of the volute 101. The air inlet of the volute 101 is located in the upper area of ​​the dust collection hopper 10. When the spiral scraper 7 cleans the filter cartridge 4, the discharged foreign objects can fall directly into the dust collection hopper 10 for collection. This facilitates the centralized cleaning of foreign objects later and effectively prevents foreign objects from being sucked back into the unit by the fan. In specific implementation, the dust collection hopper 10 can be integrally formed with the volute 101, or it can be fixedly installed on the volute 101, the housing 3, and the condensate tray 5 by bolts, clips, or other means.

[0045] In a further implementation, such as Figure 9 As shown, the output shaft 201 of the drive motor 2 has a plurality of spray holes 202 evenly distributed along the axial direction on its side wall. All spray holes 202 are located in the internal area of ​​the filter cartridge 4. The output shaft 201 has a flow channel that communicates with each spray hole 202. A rotary joint 11 is rotatably connected to the output shaft 201. The rotary joint 11 forms a sealed connection with the flow channel of the output shaft 201. A water supply unit is connected to the outside of the rotary joint 11. The water supply unit can deliver high-pressure cleaning water into the flow channel. The cleaning water is sprayed onto the inner wall of the filter cartridge 4 through the spray holes 202 to achieve high-pressure rinsing of the filter cartridge 4. A drain pipe 14 is sealed and connected to the lowest point of the volute 101. The drain pipe 14 can be selectively connected to the condensate pan 5 or the condensate pipe, thereby directing the discharge of wastewater collected at the lower end of the volute 101 during the cleaning process and preventing wastewater accumulation.

[0046] Based on the above structure, the cleaning operation of the filter cartridge 4 can be carried out by a combination of scraping and washing: firstly, the foreign matter adhering to the inner wall of the filter cartridge 4 is scraped off and discharged by the scraping action of the spiral scraper 7; then, high-pressure water is sprayed through the water spray hole 202, and the continuous rotation of the spiral scraper 7 is used to thoroughly rinse the inner wall of the filter cartridge 4, achieving deep cleaning of the filter cartridge 4. While rinsing the filter cartridge 4, the high-pressure water flow can also simultaneously rinse the surface of the centrifugal impeller 102, achieving cleaning and maintenance of the core air supply components of the unit. In actual operation, after the rinsing operation is completed, the unit needs to be kept running normally for a period of time to allow the unit's air supply to quickly dry the filter cartridge 4, centrifugal impeller 102, and the inner wall of the volute 101, avoiding problems such as scaling and corrosion caused by prolonged moisture retention.

[0047] In a specific implementation, the water supply unit can be a dedicated water supply pipeline independently configured in the central air conditioning system. The water supply pipeline is connected to a pressurized water source such as tap water. A solenoid valve is connected in series between the water supply pipeline and the rotary joint 11. The centralized supply and precise regulation of clean water for each unit are achieved by controlling the on and off of the solenoid valve.

[0048] As another preferred implementation, such as Figure 9 As shown, the water supply unit consists of a water pump device 12, a collection bottle 15, and a water delivery pipe 13. The rotary joint 11 is sealed to the output end of the water pump device 12 via a pipeline, and the input end of the water pump device 12 is connected to the collection bottle 15 via the water delivery pipe 13. The collection bottle 15 is connected to the condensate pipeline via a multi-port connector 16. Thus, when the condensate generated during unit operation is discharged through the condensate pipeline, some of the condensate is collected in the collection bottle 15. The water supply unit can directly use the collected condensate as cleaning water, which effectively reduces water waste and significantly lowers the implementation cost of cleaning operations.

[0049] Furthermore, the inlet of the collection bottle 15 is equipped with a filter screen to filter the condensate entering the collection bottle 15, preventing foreign matter from entering and affecting the cleanliness of the cleaning water; at the same time, the water outlet of the water supply pipe 13 is located on the side wall of the lower part of the collection bottle 15, so that a sedimentation zone is formed at the bottom of the collection bottle 15, and impurities in the condensate can settle naturally in the sedimentation zone, further improving the purity of the cleaning water.

[0050] In a further implementation, such as Figure 9 , Figure 10As shown, an extension tube 203 is coaxially fixedly connected to the end of the output shaft 201 away from the drive motor 2. The end of the extension tube 203 away from the output shaft 201 is a blind end structure, and its sidewall has several water spray holes 202 opened along the axial direction. The inner cavity of the extension tube 203 is sealed and connected to the flow channel of the output shaft 201. The extension tube 203 can significantly increase the axial coverage of the water spray holes 202 on the corresponding filter cartridge 4, realizing full-area rinsing of the inner wall of the filter cartridge 4, while the output shaft 201 can maintain the conventional design length, effectively avoiding problems such as unit shaking and decreased stability caused by excessive length of the output shaft.

[0051] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An energy-saving air conditioning system fan coil unit, comprising a casing, a surface cooler, a centrifugal fan, and a drive motor, wherein the centrifugal fan consists of a volute and a centrifugal impeller; characterized in that: A filter cartridge is installed at the air inlet of the volute. One end of the filter cartridge is open and is sealed and fixedly connected to the outer periphery of the air inlet. The other end of the filter cartridge has a bottom that extends into the hollow area of ​​the centrifugal impeller. The bottom has a central hole. The drive motor is a bidirectional output motor. The output shaft passes through the central hole. A rotary arm is rotatably connected to the output shaft, and a one-way transmission mechanism is provided between the two. Several spiral scrapers are fixedly connected to the rotary arm. The sides of the spiral scrapers are attached to the inner wall of the filter cartridge and extend spirally along the axial direction of the filter cartridge. When the output shaft rotates in one direction, the one-way transmission mechanism is in a disengaged state during normal air supply operation. When the output shaft rotates in the other direction, the rotary arm is driven to rotate by the one-way transmission mechanism, and the spiral scrapers scrape off the foreign matter adhering to the inner wall of the filter cartridge and discharge the scraped foreign matter to the outside of the filter cartridge.

2. The energy-saving air conditioning system fan coil unit according to claim 1, characterized in that: A cleaning component is fixedly connected to the side of the spiral scraper that is in contact with the inner wall of the filter cartridge; the cleaning component is a flexible structure such as flexible bristles or cleaning cotton.

3. The energy-saving air conditioning system fan coil unit according to claim 1, characterized in that: A bushing is fixedly installed on the center hole at the bottom of the filter cartridge, and the output shaft of the drive motor is rotatably engaged with the bushing.

4. The energy-saving air conditioning system fan coil unit according to claim 1, characterized in that: The centrifugal fan is provided in two, which are coaxially spaced on the casing, and the centrifugal impeller rotation axes of the two centrifugal fans coincide. The drive motor is mounted between two centrifugal fans. The drive motor is a special dual-shaft output motor for fan coil units, and the two output shafts are fixedly connected to the centrifugal impellers on the corresponding sides.

5. The energy-saving air conditioning system fan coil unit according to claim 1, characterized in that: The centrifugal impeller consists of a disc, several blades, and two end rings. The disc is fixedly connected to the output shaft, and the two end rings are distributed on both sides of the disc along the axial direction. The blades extend along the axial direction, with the middle part of the blades fixedly connected to the outer circle of the disc, and the two ends of the blades fixedly connected to the end rings respectively. Air inlets are provided on both opposite side walls of the volute to adapt to the bidirectional air intake structure of the centrifugal impeller.

6. The energy-saving air conditioning system fan coil unit according to claim 1, characterized in that: A dust collection hopper is fixedly installed on the lower side of the volute. The air inlet of the volute is located in the area above the dust collection hopper. When the spiral scraper cleans the filter cartridge, the discharged foreign matter falls directly into the dust collection hopper for collection.

7. The energy-saving air conditioning system fan coil unit according to claim 1, characterized in that: The output shaft has several water spray holes on its side wall, which are located inside the filter cartridge. The output shaft has a flow channel that communicates with each water spray hole. A rotary joint is rotatably connected to the output shaft, and the rotary joint communicates with the flow channel. A water supply unit is connected to the outside of the rotary joint. A drain pipe is connected to the lower end of the volute.

8. The energy-saving air conditioning system fan coil unit according to claim 7, characterized in that: The water supply unit consists of a water pump, a collection bottle, and a water delivery pipe; the rotary joint is connected to the output end of the water pump, the input end of the water pump is connected to the collection bottle via the water delivery pipe, and the collection bottle is connected to the condensate pipe via a multi-port connector.

9. The energy-saving air conditioning system fan coil unit according to claim 8, characterized in that: The inlet of the liquid collecting bottle is equipped with a filter screen, and the water outlet of the water delivery pipe is located on the side wall of the lower part of the liquid collecting bottle.

10. The energy-saving air conditioning system fan coil unit according to claim 7, characterized in that: An extension tube is fixedly connected to the end of the output shaft away from the drive motor. The end of the extension tube away from the output shaft is a blind end. Several water spray holes are opened on the side wall of the extension tube. The inner cavity of the extension tube is connected to the flow channel of the output shaft.

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