Purification type air pipe multi-split air conditioner system

Abstract

The invention relates to the technical field of air conditioning equipment, and provides a purification type air pipe multi-split air conditioning system which comprises an outdoor unit and at least one indoor unit, the outdoor unit is connected with the indoor unit through a refrigerant pipe, the indoor unit comprises an evaporator, a fan, an indoor unit filtering device and an indoor unit pressure difference monitoring device, and the fan is arranged between the evaporator and the air supply end of the indoor unit; the indoor unit filtering device is arranged at the air supply end and the air return end of the indoor unit and used for purifying and filtering air. The indoor unit pressure difference monitoring devices are arranged at the air supply end and the air return end of the indoor unit and used for monitoring the resistance of a filtering device of the indoor unit and sending out an alarm signal when the resistance reaches a preset threshold value. An independent circulating unit and a long-distance air supply and return main pipeline do not need to be additionally arranged, and ceiling space occupation is greatly reduced; the indoor unit filtering devices are arranged at the air supply end and the air return end of the indoor unit, so that the air filtering effect is improved, and the bacterium breeding risk caused by the purification type fan coil water system is avoided.

Description

Technical Field

[0001] This invention relates to the field of air conditioning equipment technology, and in particular to a purification-type duct multi-split air conditioning system. Background Technology

[0002] In medical settings and other environments with stringent air cleanliness requirements, cleanroom air conditioning systems are crucial for ensuring environmental compliance and preventing cross-infection. The air exchange rate of these systems needs to be determined based on the room's cleanliness level, and most utilize an all-air system. Supply and return air ducts extend from the cleanroom and connect to various supply and return air terminals within the clean area. To control noise, the main duct velocity is controlled below 6 m / s, branch duct velocity below 4 m / s, and terminal duct velocity below 2 m / s. This results in main duct dimensions often exceeding 1000mm × 630mm, with extremely long routes. Furthermore, clean areas cannot have direct external windows and are typically enclosed within an inner area. Smoke extraction systems, along with fire protection and electrical piping, lead to significant congestion within the ceiling, greatly complicating commissioning and maintenance.

[0003] With the rapid increase in the number of existing hospitals, apart from new projects that can solve the above problems through pre-planning, many renovation projects face the challenge of fixed existing building conditions. Unlike new projects, which can avoid problems by pre-planning space and optimizing pipeline layout, renovation projects need to balance purification process requirements with maintenance and fire protection standards without changing the original building structure or affecting the normal operation of upper-level departments (existing pipelines, fire protection, drainage and other facilities must not be demolished or altered).

[0004] This further narrows the already limited ceiling space, making the usable area even more cramped. Some renovation projects have even resulted in situations where corridor walls cannot be sealed off and excessive pipework has been installed, creating significant and difficult-to-resolve safety hazards for life and property during later use.

[0005] To address the above issues, two common solutions have emerged in the industry, but both have significant drawbacks: One type is that some renovation projects were forced to abandon the setting of a purification zone because they could not meet the space requirements of the all-air system, and adopted a combination of ordinary air conditioning and disinfection machine. Although this solution can improve air quality to a certain extent, it cancels the purification function, and chemical disinfection methods will pose a potential health hazard to medical staff who work in this environment for a long time, and cannot meet the stringent use requirements of medical facilities.

[0006] Another option is to use a purification-type fan coil unit. While this addresses the conflict between purification process requirements and limited ceiling space to some extent, it is a water-based system. As such, the placement of the outdoor heat pump must consider aesthetics, maintenance space, heat dissipation distance, and load-bearing requirements. Some projects also require structural reinforcement, resulting in extremely low cost-effectiveness. Furthermore, it is difficult to implement in existing buildings with limited server room space. The water system and the building's switching between winter and summer heating and cooling sources rely on valve control. This control link is easily affected by factors such as procurement quality, maintenance level, and equipment aging, resulting in poor operational stability. The clean area is extremely sensitive to water leaks. Leaks in the water system pipelines can lead to filter soaking and bacterial overgrowth, causing serious safety risks. In addition, the building's original heating and cooling source systems have been in operation for a long time, and the renovation process often faces the problem of missing data, resulting in deviations in the calculation of new load. Furthermore, the water pipeline routes are long and have large heat loss, which can easily lead to situations where the water temperature does not meet the design requirements, making the system's operational risks uncontrollable. Summary of the Invention

[0007] This invention provides a purification-type duct multi-split air conditioning system to solve the shortcomings of existing purification air conditioning systems in medical facilities, especially in renovation projects, such as poor spatial adaptability, difficulty in balancing purification effect and safety reliability, and complex operation and maintenance.

[0008] This invention provides a purification-type ducted multi-split air conditioning system, including an outdoor unit and at least one indoor unit, wherein the outdoor unit and the indoor unit are connected via refrigerant pipes, and the indoor unit includes: Evaporator; A fan is installed between the evaporator and the air supply end of the indoor unit; The indoor unit filter device is installed at the air supply end and the air return end of the indoor unit to purify and filter the air; An indoor unit differential pressure monitoring device is installed at the air supply end and air return end of the indoor unit to monitor the resistance of the indoor unit's filter device and issue an alarm signal when the resistance reaches a preset threshold.

[0009] According to the purification-type duct multi-split air conditioning system provided by the present invention, the indoor unit filter device includes: The first filter is located at the air supply end. The first filter is a sub-high efficiency filter with an initial resistance of no more than 120 Pa; or, the first filter is an ultra-low resistance filter with an initial resistance of no more than 20 Pa.

[0010] According to the purification-type duct multi-split air conditioning system provided by the present invention, the indoor unit differential pressure monitoring device includes: A first differential pressure sensor, located at the air supply end, is used to issue an alarm signal when the resistance of the first filter reaches twice its initial resistance.

[0011] According to the purification-type duct multi-split air conditioning system provided by the present invention, the indoor unit filter device includes: The second filter is located at the return air end. The second filter is a medium-efficiency filter with an initial resistance of no more than 80 Pa.

[0012] According to the purification-type duct multi-split air conditioning system provided by the present invention, the indoor unit differential pressure monitoring device includes: A second differential pressure sensor, located at the return air end, is used to issue an alarm signal when the resistance of the second filter reaches twice its initial resistance.

[0013] The purification-type duct multi-split air conditioning system provided by the present invention further includes an indoor unit noise reduction structure, wherein the indoor unit noise reduction structure includes: The flexible connector installed at the connection between the fan and the duct; and A sound-absorbing elbow installed at the corner of the air duct.

[0014] According to the purification-type duct multi-split air conditioning system provided by the present invention, the fan is a high static pressure fan, which is a centrifugal fan or an EC fan.

[0015] According to the purification-type duct multi-split air conditioning system provided by the present invention, when the fan noise corresponding to the required air volume of a single room exceeds a preset limit, multiple indoor units are connected in parallel to share the air volume, and each indoor unit is connected to the outdoor unit through a refrigerant pipe.

[0016] The purification-type duct multi-split air conditioning system provided by the present invention further includes a fresh air unit, which is used to independently handle the outdoor cooling and heating loads and humidity loads, and delivers the treated fresh air to the room, which mixes with the indoor return air and is then purified by the indoor unit before being delivered out.

[0017] This invention provides a purification-type ducted multi-split air conditioning system, including an outdoor unit and at least one indoor unit. The outdoor unit and the indoor unit are connected by refrigerant pipes. The indoor unit includes an evaporator, a fan, an indoor unit filter, and an indoor unit differential pressure monitoring device. The fan is located between the evaporator and the air supply end of the indoor unit. The indoor unit filter is located at both the air supply and return ends of the indoor unit for purifying and filtering the air. The indoor unit differential pressure monitoring device is located at both the air supply and return ends of the indoor unit for monitoring the resistance of the indoor unit filter and issuing an alarm signal when the resistance reaches a preset threshold. This invention integrates heat and humidity load handling (evaporator) and air purification functions into the indoor unit of the ducted multi-split air conditioning system. All indoor unit filters are equipped with differential pressure sensors to achieve real-time monitoring and automatic alarm of filter resistance, ensuring stable purification efficiency. It facilitates maintenance and replacement; the indoor unit integrates filtration, pressurization, and monitoring functions, eliminating the need for separate circulation units and long supply and return air pipelines compared to traditional air systems, significantly reducing ceiling space requirements; by using refrigerant pipelines instead of water system pipelines, it completely eliminates the risk of water pipe leaks and bacterial growth, and the system operates independently without interfering with the building's original heating and cooling systems; by installing indoor unit filters at both the supply and return air ends, it forms a dual filtration design of return air pretreatment and supply air deep purification, significantly improving air filtration efficiency and meeting the requirements of Grade III cleanrooms in hospitals. It also avoids the risk of bacterial growth caused by water-based fan coil systems. Furthermore, by placing the indoor unit filters at the air outlet end, replacement can be completed without dismantling or modifying the pipeline, achieving precise and convenient operation and maintenance. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0019] Figure 1 This is a structural schematic diagram of a purification-type duct multi-split air conditioning system provided in an embodiment of the present invention.

[0020] Figure 2 This is a structural schematic diagram of a purification-type duct multi-split air conditioning system provided in another embodiment of the present invention.

[0021] Figure 3 This is a performance curve diagram of the purification-type duct multi-split air conditioning system provided in the embodiments of the present invention.

[0022] Figure 4 This is a performance curve diagram of a purification-type duct multi-split air conditioning system provided in another embodiment of the present invention.

[0023] Figure 5 This is an enthalpy-humidity diagram of the summer air handling process of a purification-type duct multi-split air conditioning system provided in an embodiment of the present invention.

[0024] Figure label: 1. Fan; 2. First filter; 3. Second filter; 4. Flexible connector; 5. Silencing elbow; 6. Side air inlet; 7. Insulation layer; 8. Air duct; 9. Evaporator; 10. Refrigerant pipe. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this 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 this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0026] The following is combined Figures 1 to 5 This invention describes a purification-type duct multi-split air conditioning system.

[0027] Reference Figure 1 , Figure 2 This invention provides a purification-type ducted multi-split air conditioning system, including an outdoor unit and at least one indoor unit. The outdoor unit and the indoor unit are connected by a refrigerant pipe 10. The indoor unit includes an evaporator 9, a fan 1, an indoor unit filter device, and an indoor unit differential pressure monitoring device. The fan 1 is disposed between the evaporator 9 and the air supply end of the indoor unit. The indoor unit filter device is disposed at the air supply end and the air return end of the indoor unit for purifying and filtering the air. The indoor unit differential pressure monitoring device is disposed at the air supply end and the air return end of the indoor unit for monitoring the resistance of the indoor unit filter device and issuing an alarm signal when the resistance reaches a preset threshold.

[0028] As can be seen from the above scheme, this invention integrates heat and humidity load handling (evaporator 9) and air purification functions into the indoor unit of a multi-split air conditioning system. All indoor unit filters are equipped with differential pressure sensors to achieve real-time monitoring and automatic alarm of filter resistance, ensuring stable purification efficiency and facilitating maintenance and replacement. This allows the indoor unit to integrate filtration, pressurization, and monitoring functions. Compared with traditional air systems, it eliminates the need for separate independent circulation units and long-distance supply and return air ducts, significantly reducing the space occupied by the ceiling. By using 10 refrigerant pipes to replace water system pipes, the risk of water pipe leakage and bacterial growth is completely eliminated, and the system operates independently without interfering with the building's original heating and cooling systems. This invention utilizes indoor unit filters at both the supply and return air ends to create a dual filtration design that combines return air pretreatment with deep supply air purification. This significantly improves air filtration efficiency, meeting the requirements of Grade III cleanrooms in hospital operating rooms. It also avoids the risk of bacterial growth associated with water systems in purification fan coil units. Furthermore, by placing the indoor unit filters at the air outlet end, replacement can be completed without dismantling or modifying the piping, enabling precise and convenient operation and maintenance. This invention addresses the challenges of limited building space, cramped ceilings, and the inability to modify existing piping in hospital renovation projects, reducing the amount of dismantling and structural requirements, and ensuring that purification effects and operational efficiency are not affected by external systems.

[0029] like Figures 1-2 As shown, the indoor unit includes a supply air section, a return air section, an evaporator 9, a fan 1, and multiple air ducts 8 for connection. Indoor air enters the return air section through the return air end and flows directly to the evaporator 9 side to complete the airflow pretreatment before heat and humidity exchange. After heat exchange by the evaporator 9, the air is pressurized by the fan 1 and sent out through the supply air end. The evaporator 9 is connected to the return air section and the supply air section through sealed air ducts 8 or a housing to avoid airflow leakage and ensure purification efficiency and heat exchange effect.

[0030] Optionally, both the air duct 8 and the housing are made of 20mm thick thermal insulation cotton.

[0031] It should be noted that the evaporator 9 is a product of existing technology, and its structure and principle in the air purification system are not the focus of this article and will not be elaborated here.

[0032] In some embodiments, the outdoor unit includes a compressor, a condenser, a liquid receiver, and an expansion valve. The compressor compresses low-temperature, low-pressure refrigerant gas into high-temperature, high-pressure gas. The condenser dissipates heat to the outdoor atmosphere via air cooling, causing the high-temperature, high-pressure refrigerant gas to condense into a liquid. The condensed refrigerant is then transported to each indoor unit through refrigerant pipes 10. The refrigerant flow rate is precisely regulated by the electronic expansion valve. The indoor unit's evaporator 9 exchanges heat with the indoor air, achieving efficient handling of indoor heat and humidity loads. The fresh air unit independently handles the heating, cooling, and humidity loads of the outdoor fresh air. After treating the fresh air to the set supply air temperature, it is delivered indoors, mixed with indoor return air, and then purified and filtered by the indoor unit. This avoids energy waste caused by direct fresh air treatment while ensuring the stability of the supply air temperature and humidity.

[0033] In some embodiments, both the air supply section and the return air section are box structures, each equipped with an indoor unit filter device such as a filter. The air supply section is also equipped with a side air inlet 6. The fan 1 is located between the evaporator 9 and the air supply section. That is, after the airflow passes through the evaporator 9 for heat exchange, it is first pressurized by the fan 1 and then sent to the air supply section.

[0034] Preferably, both the supply air section and the return air section are equipped with an insulation layer 7. On the one hand, this blocks the heat exchange between the inside and outside of the pipeline, preventing condensation from forming on the inner wall of the duct 8 due to temperature differences during airflow, thus preventing bacterial growth and equipment corrosion caused by condensation leakage. On the other hand, it reduces heat loss, ensures stable airflow temperature after treatment by the evaporator 9, improves heat exchange efficiency, and reduces system energy consumption.

[0035] In this embodiment, the indoor unit's filtration device includes a first filter 2, which is installed at the air supply end. The first filter 2 is a sub-high-efficiency filter with an initial resistance of no more than 120 Pa; or, the first filter 2 is an ultra-low-resistance filter with an initial resistance of no more than 20 Pa, a filtration efficiency of ≥80% for particles with a diameter ≥0.5 μm, and an airflow range of 300-1500 m³ / h. 3 / h, compatible with Class IV cleanrooms in the "Technical Specifications for Clean Operating Rooms in Hospitals".

[0036] It should be noted that initial resistance refers to the initial resistance encountered by air passing vertically through the filter media when the air filter, such as a sub-HEPA filter, medium-efficiency filter, or ultra-low resistance indoor unit filter, is in a brand-new, unused state with no dust accumulation. It is one of the filter's performance parameters. The lower the initial resistance, the less energy is consumed when air passes through the filter, the lower the fan load, and the easier it is to control noise.

[0037] Furthermore, the indoor unit differential pressure monitoring device includes a first differential pressure sensor, which is located at the air supply end and is used to issue an alarm signal when the resistance of the first filter 2 reaches twice its initial resistance.

[0038] With this setup, dust will accumulate in the filter during use, and the resistance will gradually increase. When the differential pressure sensor detects that the resistance has reached the target resistance, it will automatically alarm to prompt the replacement or cleaning of the filter. This will prevent the wind speed from increasing due to excessive resistance (wind speed is directly proportional to resistance), which could lead to problems such as excessive noise and reduced purification efficiency.

[0039] When using a differential pressure sensor, its working principle is as follows: The two pressure sampling ports of the differential pressure sensor are connected to both sides of the filter, one sampling port facing the air inlet side and the other facing the air outlet side, forming a pressure difference detection loop. When the filter is brand new (initial resistance state), the filter media is free of dust, and the resistance to air passing through the filter media is small; the pressure difference between the two sides is the initial resistance. As the usage time increases, dust gradually accumulates on the surface of the filter media, increasing the resistance to air passing through the filter media, resulting in the pressure difference between the air inlet side and the air outlet side, i.e., the resistance continues to rise. The sensor converts the real-time detected pressure difference (ΔP) into an electrical signal (such as voltage or current signal) and transmits it to the external control system. When the detected pressure difference reaches a preset threshold, such as twice the set initial resistance, the control system triggers an alarm signal, prompting the user to replace the filter.

[0040] In this embodiment, the indoor unit filtration device also includes a second filter 3, which is installed at the return air end. The second filter 3 is a medium-efficiency filter with an initial resistance of no more than 80 Pa.

[0041] Furthermore, the indoor unit differential pressure monitoring device includes a second differential pressure sensor, which is located at the return air end and is used to issue an alarm signal when the resistance of the second filter 3 reaches twice its initial resistance.

[0042] With this setup, when air enters the indoor unit from the return air end, it first passes through a medium-efficiency filter to remove most particulate matter. After heat exchange in the evaporator 9, it undergoes deep purification by a sub-high-efficiency filter or an ultra-low resistance indoor unit filter at the supply air end, ensuring that the output air meets the corresponding cleanliness level requirements. As dust accumulates in the indoor unit filter, the resistance gradually increases. When the differential pressure sensor detects that the resistance reaches twice the initial resistance, an alarm signal is triggered, prompting the filter to be replaced. This prevents excessive resistance from causing increased airflow, noise, or decreased purification efficiency.

[0043] Optionally, fan 1 is a high static pressure fan, which can be a centrifugal fan or an EC fan. Since the system is geared towards independent room air conditioning, the air volume is generally small, but the air pressure is relatively large. A centrifugal fan is used to convert static pressure through a volute. Backward curved blades are used to improve efficiency while reducing eddies. Noise reduction is achieved by combining the equipment with the silencer elbow 5.

[0044] The EC DC brushless fan avoids the noise generated by friction during mechanical commutation using carbon brushes and slip rings in traditional three-phase asynchronous motors. Its permanent magnets offer a more uniform air gap compared to squirrel-cage motors, effectively preventing electromagnetic vibration noise. Continuous speed regulation via PWM signals or 0-10V voltage avoids the mechanical vibration noise caused by gear switching and frequency conversion in traditional fans. Its electronic controller reduces harmonic interference and prevents core vibration caused by periodic changes in the stator winding magnetic field, thus reducing electromagnetic noise.

[0045] Reference Figure 3 Table 1 shows the configuration of sub-HEPA and medium-HEPA filters with EC fans, targeting an operating air volume of 1000 m³ / h. 3 For a system with a capacity of / h, the noise level of fan 1 is ≤57dB(A).

[0046] Table 1

[0047] Reference Figure 4 Table 2 shows the results for operating air volumes of 1000 m³ / h using ultra-low resistance filters and EC fans. 3 For a system with a capacity of / h, the noise level of fan 1 is ≤47dB(A).

[0048] Table 2

[0049] In this embodiment, an indoor unit noise reduction structure is also included. The indoor unit noise reduction structure includes a flexible connector 4 installed at the connection between the high static pressure fan and the duct 8. The flexible connector 4 can be a smooth rubber flexible connector. And a sound-absorbing elbow 5 installed at the corner of the duct 8.

[0050] This design addresses low-frequency noise, primarily caused by structural vibrations and large airflow vortices generated by the operation of fan 1. The rubber-based flexible connector 4, with its excellent elastic damping performance, effectively blocks vibration transmission between the high static pressure fan and duct 8, reducing structural resonance noise at its source. The smooth material design reduces airflow friction resistance as air passes through the connector, preventing aggravated airflow disturbances caused by rough materials and further reducing turbulent noise. Simultaneously, the rubber material's sealing properties prevent airflow leakage, ensuring stable airflow. The silencer elbow 5, through optimized airflow channel structure, guides airflow smoothly to a different direction, reducing vortices, impacts, and separation at corners, thus minimizing noise spikes caused by localized resistance. This contributes to achieving low-noise operation, significantly lower than the noise levels of traditional all-air systems or purification fan coil units, providing a quiet working environment for medical staff while preventing high noise levels from interfering with patient recovery, meeting the specific requirements of medical facilities.

[0051] In this embodiment, when the noise level of fan 1 corresponding to the required air volume of a single room exceeds a preset limit, multiple indoor units are connected in parallel to distribute the air volume. Each indoor unit is connected to the outdoor unit through a refrigerant pipe 10. For example, when the operating noise of the indoor unit is ≤48dB(A), two or more small-volume fans 1 are used to distribute the required air volume of the room to meet the noise control requirements.

[0052] Optionally, each indoor unit is equipped with an electronic expansion valve, which is installed inside the indoor unit or in an external expansion box. The electronic expansion valve is used to precisely adjust the refrigerant flow into the indoor unit according to the load changes of the corresponding area, so as to achieve independent control of different areas.

[0053] In some embodiments, the air supply end is located in the ceiling, and the return air end is located in the ceiling or on a side wall near the ground. That is, the indoor unit can be designed as an upward-supplying, upward-returning structure or an upward-supplying, downward-returning structure; wherein, for example... Figure 1 As shown, the top-supply and top-return structure is as follows: both the supply air outlet and the return air outlet are located in the ceiling. The supply air velocity of the supply air outlet is ≤1m / s, and the suction air velocity of the return air outlet is ≤1m / s. It is suitable for corridors, warehouses and other areas with no or few people.

[0054] like Figure 2 As shown, the top-supply, bottom-return structure is as follows: the air supply outlet is located in the ceiling with a supply air velocity ≤2m / s, and the return air outlet is located on the side wall with the upper edge of the return air outlet ≤0.5m from the ground and the lower edge ≥0.1m from the ground; the supply air velocity of the air supply outlet is ≤1m / s, and the suction air velocity of the return air outlet is ≤1m / s. It is suitable for Class 300,000 clean areas with bottom-return air requirements, such as ICU, recovery room, and pre-anesthesia room.

[0055] Furthermore, when using a combination of sub-high efficiency and medium efficiency filters: the residual pressure of fan 1 in the indoor unit with top-supply and top-return installation is ≥410Pa, and the residual pressure of fan 1 in the indoor unit with top-supply and bottom-return installation is ≥450Pa; when using an ultra-low resistance indoor unit filter device: the residual pressure of fan 1 in the indoor unit with top-supply and top-return installation is ≥50Pa, and the residual pressure of fan 1 in the indoor unit with top-supply and bottom-return installation is ≥80Pa.

[0056] Both of the above installation methods strictly control the wind speed to ensure uniform airflow and avoid discomfort caused by excessively high local wind speeds; the top-supply and bottom-return type forms a reasonable airflow circulation through the low-position return air inlet design on the side wall, reducing the accumulation of pollutants in the clean area.

[0057] Preferably, it also includes a fresh air handling unit, which is used to independently handle the outdoor cooling and heating loads and humidity loads in winter and summer. After the fresh air is treated to the set supply air temperature, it is sent into the room and mixed with the indoor return air. After being purified by the indoor unit, it is sent out.

[0058] Reference Figure 5The enthalpy-humidity diagram for the summer air handling process of this invention is defined as follows: The horizontal axis represents the moisture content ε (the amount of water vapor carried by the air, in kg / kg dry air), and the vertical axis represents the specific enthalpy h (the total heat contained in the air, in kJ / kg dry air). The diagonal line "ξ" in the figure is the heat-moisture ratio line, which represents the direction of air state change corresponding to the indoor heat and moisture load. That is, after the supply air is sent into the room, it needs to change along this line to the indoor return air state.

[0059] The correspondence between state points and processing procedures: Point W: The initial state point of outdoor air in summer (high enthalpy h, high humidity ε); W→L1: Outdoor fresh air is cooled by the surface cooling of the fresh air unit (cooling + dehumidification), and its enthalpy and moisture content are reduced simultaneously, reaching the L1 state; L1→W': After surface cooling, the fresh air is reheated by the fresh air unit (equal humidity and temperature rise, constant moisture content and increased enthalpy) to obtain the pre-treated fresh air state W'; N point: The return air status point after indoor use (the air status of the indoor area); N→L2: The indoor unit evaporator 9 exchanges heat, and the indoor return air is treated by the surface cooling of the indoor unit (cooling + dehumidification) to match the indoor heat and humidity load requirements and reach the L2 state; W' mixes with L2 → point C: Fresh air and return air are mixed, and according to the preset fresh air / recirculated air ratio, the air supply state point C is obtained along the "mixing line" from W' to L2 (point C must meet the air supply temperature difference requirements); finally, point C is sent into the room along the heat-moisture ratio line ξ to bear the indoor heat and humidity load.

[0060] In this air handling process, the fresh air unit independently handles the cooling, heating, and humidity load of the outdoor fresh air W (completing the processing of W→L1→W'), avoiding the energy waste caused by the traditional system's "mixing of fresh air and return air and then centralized processing"; The indoor unit only handles the heat and humidity load of the indoor return air N (completing the N→L2 process), and in conjunction with its internal evaporator 9, it precisely matches the heat and humidity requirements of the indoor area.

[0061] By integrating the surface cooling treatment (N→L2) of the indoor unit with the filters and high static pressure fans at the supply and return air ends, air purification is achieved simultaneously while completing heat and humidity treatment, eliminating the need for additional purification equipment. The insulation layer 7 of the supply and return air sections can reduce the enthalpy and humidity loss of the airflow at L2, W', and the mixed point C, avoiding condensation / temperature changes during airflow transportation and ensuring stable air supply. The electronic expansion valve of the indoor unit can precisely adjust the refrigerant flow according to the processing requirements of N→L2, achieving independent control of different areas.

[0062] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A purification-type duct multi-split air conditioning system, characterized in that, The unit includes an outdoor unit and at least one indoor unit, the outdoor unit and the indoor unit being connected via a refrigerant pipe (10), the indoor unit comprising: Evaporator (9); A fan (1) is disposed between the evaporator (9) and the air supply end of the indoor unit; The indoor unit filter device is installed at the air supply end and the air return end of the indoor unit to purify and filter the air; An indoor unit differential pressure monitoring device is installed at the air supply end and air return end of the indoor unit to monitor the resistance of the indoor unit's filter device and issue an alarm signal when the resistance reaches a preset threshold.

2. The cleanroom-type duct multi-split air conditioning system according to claim 1, characterized in that, The indoor unit filtration device includes: The first filter (2) is set at the air supply end. The first filter (2) is a sub-high efficiency filter with an initial resistance of no more than 120 Pa; or, the first filter (2) is an ultra-low resistance filter with an initial resistance of no more than 20 Pa.

3. The purification-type duct multi-split air conditioning system according to claim 2, characterized in that, The indoor unit differential pressure monitoring device includes: A first differential pressure sensor is installed at the air supply end to issue an alarm signal when the resistance of the first filter (2) reaches twice its initial resistance.

4. The purification-type duct multi-split air conditioning system according to claim 3, characterized in that, The indoor unit filtration device includes: The second filter (3) is set at the return air end. The second filter (3) is a medium-efficiency filter with an initial resistance of no more than 80 Pa.

5. The purification-type duct multi-split air conditioning system according to claim 4, characterized in that, The indoor unit differential pressure monitoring device includes: A second differential pressure sensor is installed at the return air end to issue an alarm signal when the resistance of the second filter (3) reaches twice its initial resistance.

6. The cleanroom-type duct multi-split air conditioning system according to claim 1, characterized in that, It also includes an indoor unit noise reduction structure, which comprises: A flexible connector (4) is installed at the connection between the fan (1) and the duct (8); and A sound-absorbing elbow (5) is installed at the corner of the air duct (8).

7. The cleanroom-type duct multi-split air conditioning system according to claim 6, characterized in that, The fan (1) is a high static pressure fan, which is a centrifugal fan or an EC fan.

8. The purification-type duct multi-split air conditioning system according to any one of claims 1-7, characterized in that, When the noise of the fan (1) corresponding to the required air volume of a single room exceeds the preset limit, multiple indoor units are connected in parallel to share the air volume. Each indoor unit is connected to the outdoor unit through a refrigerant pipe (10).

9. The purification-type duct multi-split air conditioning system according to any one of claims 8, characterized in that, The air supply end is located in the ceiling, and the air return end is located in the ceiling or on a side wall near the ground.

10. The cleanroom-type duct multi-split air conditioning system according to claim 8, characterized in that, It also includes a fresh air handling unit, which is used to independently handle the outdoor cooling and heating loads and humidity loads, and delivers the treated fresh air to the room. After mixing with the indoor return air, the fresh air is purified by the indoor unit and then sent out.

Images