Secondary return air conditioning unit

Abstract

The utility model relates to the field of air conditioning, and provides a secondary return air air conditioning unit. The secondary return air air conditioning unit comprises an air cavity, in which an air inlet cavity, a primary return air cavity, a secondary return air cavity, an air supply cavity and an exhaust cavity which are fluid-connected are arranged, a first air valve is arranged between the air inlet cavity and the air supply cavity, and a second air valve is arranged between the primary return air cavity and the air inlet cavity; a first air supply fan is arranged between the air inlet cavity and the air supply cavity; a second air supply fan is arranged between the secondary return air cavity and the air supply cavity; an exhaust fan is arranged in the exhaust cavity; and a control component is suitable for adjusting the opening and closing of the first air valve and the second air valve based on the operation mode of the air conditioning unit. The secondary return air air conditioning unit can fully mix indoor air with outdoor air, increase the quality of indoor air; reduce the demand for cooling and reheating; reduce the consumption of chilled water and hot water, thereby reducing the power consumption and operation cost of the unit.

Description

Technical Field

[0001] The utility model relates to the field of air conditioning and provides a secondary return air air conditioning unit. Background Art

[0002] In related technologies, as people's requirements for indoor environmental comfort continue to increase, traditional air conditioning units can no longer meet the needs of all occasions. This is especially true in large buildings such as shopping malls, office buildings, and hospitals, where requirements for air quality, temperature control, and energy efficiency are even more stringent.

[0003] Traditional air conditioning units typically use a single-return air system, mixing indoor air with fresh air, processing it, and then delivering it indoors. However, this system has several drawbacks, including high energy consumption, poor air circulation, and inaccurate control of indoor temperature and humidity. Utility Model Content

[0004] The present invention aims to solve at least one of the technical problems existing in the related art. To this end, the present invention proposes a secondary return air conditioning unit that can improve the comfort, energy efficiency and air quality of the indoor environment.

[0005] The present invention provides a secondary return air air conditioning unit, comprising:

[0006] An air cavity, wherein an air inlet cavity, a primary air return cavity, a secondary air return cavity, an air supply cavity, and an air exhaust cavity are provided in the air cavity, wherein a first air valve is provided between the air inlet cavity and the air supply cavity, and a second air valve is provided between the primary air return cavity and the air inlet cavity;

[0007] a first blower, disposed between the air inlet cavity and the air supply cavity;

[0008] a second blower, disposed between the secondary return air cavity and the air supply cavity;

[0009] an exhaust fan, arranged in the exhaust cavity;

[0010] A control component is adapted to adjust the opening and closing of the first air valve and the second air valve based on an operating mode of the air conditioning unit.

[0011] The secondary return air air conditioning unit provided by the embodiment of the present invention, through the fluid connection design within the air cavity, includes an air inlet cavity, a primary return air cavity, a secondary return air cavity, an air supply cavity and an exhaust cavity, so that the indoor air circulation is smoother, thereby improving the air quality. In particular, the secondary return air design can fully mix the indoor air with the outdoor air, thereby improving the quality of the indoor air. The secondary return air system can effectively reduce energy consumption and operating costs. Compared with the traditional primary return air system, the secondary return air system reduces the amount of air cooled and dehumidified by the surface cooler, thereby reducing the demand for cooling and reheating. This can not only reduce the initial investment of the air conditioning unit, but also reduce the consumption of chilled water and hot water, thereby reducing the power consumption and operating costs of the unit. Because the secondary return air system can mix the indoor air with the outdoor air, the supply air flow is more uniform, reducing the discomfort caused by the air to the human body. This design helps to provide a more comfortable living and working environment. By setting the first air valve and the second air valve, and coordinating the precise control of the control component, the opening and closing of the air valve can be adjusted according to the operating mode of the air-conditioning unit, thereby achieving precise control of the ratio of primary return air and secondary return air. This control mechanism helps to balance the indoor heat distribution and achieve a more comfortable use effect. The secondary return air air-conditioning unit is suitable for large buildings such as large shopping malls, office buildings, and hospitals, and can meet the high requirements of these places for air quality and comfort. In summary, the secondary return air air-conditioning unit provided in the embodiment of the present utility model can optimize air circulation, precisely control air flow, improve energy efficiency, and enhance comfort and applicability.

[0012] According to one embodiment of the present invention, the air inlet cavity includes:

[0013] a first air inlet cavity, wherein an air inlet is formed on the first air inlet cavity and the first air valve is disposed in the first air inlet cavity;

[0014] The second air inlet cavity is arranged adjacent to the first air inlet cavity, and a third air valve is arranged between the second air inlet cavity and the first air inlet cavity.

[0015] According to one embodiment of the present invention, a first surface cooler is provided between the air outlet of the first air inlet cavity and the first air blower;

[0016] A second surface cooler is provided between the air outlet of the second air inlet cavity and the second air blower.

[0017] According to one embodiment of the present invention, filters are provided between the air outlet of the first air inlet cavity and the first surface cooler, and between the air outlet of the second air inlet cavity and the second surface cooler.

[0018] According to one embodiment of the present invention, the filter includes a primary filter and a secondary filter. Along the air supply direction, the primary filter is arranged upstream of the secondary filter.

[0019] According to one embodiment of the present invention, a water receiving pan is provided below the first surface cooler and the second surface cooler.

[0020] According to one embodiment of the present invention, a secondary return air port is provided on the secondary return air cavity, a secondary return air valve is provided on the secondary return air port, and the secondary return air cavity is provided between the second air inlet cavity and the air supply cavity.

[0021] According to one embodiment of the present invention, the primary return air cavity is arranged between the second air inlet cavity and the air exhaust cavity, and the second air valve is arranged in the second air inlet cavity.

[0022] According to one embodiment of the present invention, a humidifier is provided between the air outlet of the first air inlet cavity, the air outlet of the second air inlet cavity and the air supply cavity.

[0023] According to one embodiment of the present invention, an exhaust valve is provided between the primary return air cavity and the exhaust cavity.

[0024] The above one or more technical solutions in the embodiments of the present invention have at least one of the following technical effects:

[0025] The secondary return air air conditioning unit provided by the embodiment of the present invention, through the fluid connection design within the air cavity, includes an air inlet cavity, a primary return air cavity, a secondary return air cavity, an air supply cavity and an exhaust cavity, so that the indoor air circulation is smoother, thereby improving the air quality. In particular, the secondary return air design can fully mix the indoor air with the outdoor air, thereby improving the quality of the indoor air. The secondary return air system can effectively reduce energy consumption and operating costs. Compared with the traditional primary return air system, the secondary return air system reduces the amount of air cooled and dehumidified by the surface cooler, thereby reducing the demand for cooling and reheating. This can not only reduce the initial investment of the air conditioning unit, but also reduce the consumption of chilled water and hot water, thereby reducing the power consumption and operating costs of the unit. Because the secondary return air system can mix the indoor air with the outdoor air, the supply air flow is more uniform, reducing the discomfort caused by the air to the human body. This design helps to provide a more comfortable living and working environment. By setting the first air valve and the second air valve, and coordinating the precise control of the control component, the opening and closing of the air valve can be adjusted according to the operating mode of the air-conditioning unit, thereby achieving precise control of the ratio of primary return air and secondary return air. This control mechanism helps to balance the indoor heat distribution and achieve a more comfortable use effect. The secondary return air air-conditioning unit is suitable for large buildings such as large shopping malls, office buildings, and hospitals, and can meet the high requirements of these places for air quality and comfort. In summary, the secondary return air air-conditioning unit provided in the embodiment of the present utility model can optimize air circulation, precisely control air flow, improve energy efficiency, and enhance comfort and applicability.

[0026] Additional aspects and advantages of the present invention will be given in part in the following description and will become apparent from the following description or learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the present invention or the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0028] Figure 1 It is a schematic structural diagram of the secondary return air air conditioning unit provided by the embodiment of the utility model in the winter and summer air supply states.

[0029] Figure 2 It is a schematic structural diagram of the secondary return air air conditioning unit provided by an embodiment of the present utility model in a fresh air supply state.

[0030] Reference numerals:

[0031] 100, primary return air cavity; 102, secondary return air cavity; 104, supply air cavity; 106, exhaust air cavity; 108, first air valve; 110, second air valve; 112, first supply air fan; 114, second supply air fan; 116, exhaust air fan; 118, first air inlet cavity; 120, air inlet; 122, second air inlet cavity; 124, third air valve; 126, first surface cooler; 128, second surface cooler; 130, primary filter; 132, secondary filter; 134, water tray; 136, humidifier; 138, exhaust valve. DETAILED DESCRIPTION

[0032] The following embodiments of the present invention are described in further detail with reference to the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0033] like Figures 1 to 2 As shown, an embodiment of the utility model provides a secondary return air air-conditioning unit, including an air cavity, a first supply air fan 112, a second supply air fan 114, an exhaust fan 116 and a control component (not shown in the figure); an air inlet cavity, a primary return air cavity 100, a secondary return air cavity 102, an air supply cavity 104 and an exhaust cavity 106 that are fluid-connected are provided in the air cavity, a first air valve 108 is provided between the air inlet cavity and the air supply cavity 104, and a second air valve 110 is provided between the primary return air cavity 100 and the air inlet cavity; the first supply air fan 112 is provided between the air inlet cavity and the air supply cavity 104; the second supply air fan 114 is provided between the secondary return air cavity 102 and the air supply cavity 104; the exhaust fan 116 is provided in the exhaust cavity 106; the control component is suitable for adjusting the opening and closing of the first air valve 108 and the second air valve 110 based on the operating mode of the air-conditioning unit.

[0034] The secondary return air conditioning unit provided by the embodiment of the present invention utilizes a fluid-connected design within the air cavity, including an air inlet cavity, a primary return air cavity 100, a secondary return air cavity 102, an air supply cavity 104, and an exhaust cavity 106, to facilitate smoother indoor air circulation, thereby improving air quality. In particular, the secondary return air design allows for thorough mixing of indoor and outdoor air, enhancing indoor air quality. The secondary return air system can effectively reduce energy consumption and operating costs. Compared to traditional primary return air systems, the secondary return air system reduces the amount of air required for cooling and dehumidification through the surface cooler, thereby reducing the need for cooling and reheating. This not only reduces the initial investment in the air conditioning unit, but also reduces the consumption of chilled and hot water, thereby reducing the unit's power consumption and operating costs. Because the secondary return air system can mix indoor and outdoor air, the supply air flow is more uniform, reducing the discomfort caused by the air. This design helps provide a more comfortable living and working environment. By setting the first air valve 108 and the second air valve 110, in conjunction with the precise regulation of the control component, the opening and closing of the air valve can be adjusted according to the operating mode of the air-conditioning unit, thereby achieving precise control of the ratio of primary return air and secondary return air. This control mechanism helps to balance the indoor heat distribution and achieve a more comfortable use effect. The secondary return air air-conditioning unit is suitable for large buildings such as large shopping malls, office buildings, and hospitals, and can meet the high requirements of these places for air quality and comfort. In summary, the secondary return air air-conditioning unit provided in the embodiment of the present utility model can optimize air circulation, accurately control air flow, improve energy efficiency, and enhance comfort and applicability.

[0035] Please continue to see Figure 1 and Figure 2 The secondary return air air conditioning unit provided by the embodiment of the present invention is intended to optimize indoor air circulation, improve air quality and energy saving effect.

[0036] The core part of the secondary return air air conditioning unit lies in the setting of the air cavity. Multiple cavities are set inside the air cavity to ensure smooth and efficient air circulation.

[0037] like Figure 1 As shown, the air cavity mainly includes an air inlet cavity for introducing outdoor fresh air. The air inlet cavity is usually connected to the outdoor air duct to ensure that the outdoor air can smoothly enter the unit.

[0038] The primary return air cavity 100 is used to collect used air in the room. This air is usually sucked into the unit through the indoor return air inlet and enters the primary return air cavity 100 .

[0039] The secondary return air cavity 102 collects indoor air that has undergone preliminary processing (such as cooling, heating, filtering, etc.). Before being sent back into the room, this air will be mixed with fresh air again to ensure the quality of the air sent into the room.

[0040] The air supply cavity 104 is used to deliver the processed air into the room through the air supply port, thereby providing a comfortable temperature and humidity for the room.

[0041] The exhaust cavity 106 is used to exhaust unnecessary or polluted air in the room to ensure fresh indoor air.

[0042] In addition, a first air valve 108 is provided between the air inlet cavity and the air supply cavity 104 to control the flow of outdoor fresh air. When the unit is in different operating modes, the control unit adjusts the opening of the first air valve 108 to change the amount of fresh air entering the unit.

[0043] The second air valve 110 is provided between the primary return air chamber 100 and the air inlet chamber to control the flow of the primary return air. Similarly, the control unit adjusts the opening of the second air valve 110 according to the operating mode of the unit to change the amount of the primary return air.

[0044] The first blower 112 is installed between the air inlet cavity and the air supply cavity 104, and is responsible for sending the air mixed with the outdoor fresh air and the primary return air into the air supply cavity 104. By adjusting the speed of the first blower 112, the air flow rate sent into the air supply cavity 104 can be controlled.

[0045] The second blower 114 is located between the secondary return air cavity 102 and the air supply cavity 104 and is used to send the air in the secondary return air cavity 102 into the air supply cavity 104 to mix with the fresh air. By adjusting the speed of the second blower 114, the amount of secondary return air can be controlled.

[0046] The exhaust fan 116 is arranged in the exhaust cavity 106 and is responsible for exhausting the unnecessary or polluted air in the room to the outside. The speed of the exhaust fan 116 can be adjusted as needed to ensure the freshness and circulation of the indoor air.

[0047] The control unit is used to automatically adjust the status of the first damper 108, the second damper 110, the first blower 112, and the second blower 114 based on the operating mode of the air conditioning unit (e.g., summer cooling, winter heating, fresh air mode, etc.) and indoor and outdoor environmental conditions (e.g., temperature, humidity, air quality, etc.) to achieve optimal operating performance and energy conservation. The control unit can also receive user operation instructions and adjust the operating status of the unit according to user needs.

[0048] Through the above design, the secondary return air air conditioning unit provided by the embodiment of the utility model can realize the recycling of indoor air, reduce energy consumption, improve air quality, and provide users with a comfortable and healthy indoor environment.

[0049] According to one embodiment of the present invention, the air inlet cavity includes a first air inlet cavity 118 and a second air inlet cavity 122; an air inlet 120 is opened on the first air inlet cavity 118 and the first air valve 108 is arranged in the first air inlet cavity 118; the second air inlet cavity 122 is arranged adjacent to the first air inlet cavity 118 and a third air valve 124 is arranged between the second air inlet cavity 122 and the first air inlet cavity 118.

[0050] An air inlet 120 is defined within the first air inlet chamber 118, which draws fresh outdoor air into the air conditioning unit. A first damper 108 is disposed within the first air inlet chamber 118 and controls the amount of fresh air entering the unit. Depending on the operating mode of the air conditioning unit, the controller adjusts the opening of the first damper 108 to meet the indoor fresh air demand.

[0051] The second air inlet chamber 122 is disposed adjacent to the first air inlet chamber 118. That is, the second air inlet chamber 122 and the first air inlet chamber 118 share the same physical space, but the air flow path is separated by a third damper 124. In certain circumstances, such as when the outdoor air quality is poor, the air inlet 120 of the first air inlet chamber 118 and the first damper 108 can be closed, and only pre-processed (e.g., filtered, heated / cooled, etc.) air is introduced through the second air inlet chamber 122 to ensure indoor air quality.

[0052] The third air valve 124 is disposed between the first air inlet chamber 118 and the second air inlet chamber 122 to control the air flow between the two air inlet chambers. When both outdoor fresh air and pre-conditioned air are required, the third air valve 124 can be opened to allow the air from the two air inlet chambers to mix before entering the air supply chamber 104.

[0053] The controller comprehensively determines and adjusts the status of the first damper 108, the second damper 110, the third damper 124, and the blower based on the air conditioning unit's operating mode, indoor and outdoor environmental conditions, and user needs to achieve optimal operating and energy-saving results. For example, when outdoor air quality is poor, the first air inlet chamber 118 and the first damper 108 can be closed, and only pre-conditioned air can be introduced through the second air inlet chamber 122. When the amount of fresh air indoors needs to be increased, the first air inlet chamber 118 and the first damper 108 can be opened, and the opening of the third damper 124 can be adjusted as needed.

[0054] Through this design, the secondary return air air conditioning unit of the embodiment of the utility model can more flexibly respond to different environments and needs, and improve indoor air quality and comfort.

[0055] According to one embodiment of the present invention, a first surface cooler 126 is provided between the air outlet of the first air inlet cavity 118 and the first blower 112 ; a second surface cooler 128 is provided between the air outlet of the second air inlet cavity 122 and the second blower 114 .

[0056] First surface cooler 126 is installed between the outlet of first air inlet chamber 118 and first blower 112. When outdoor air enters through first air inlet chamber 118, it is first cooled by first surface cooler 126. First surface cooler 126 uses a refrigerant, such as refrigerant or chilled water, to lower the air temperature to a set value through heat exchange, thereby meeting indoor cooling requirements.

[0057] Second surface cooler 128 is installed between the outlet of second air inlet chamber 122 and second blower 114. When primary return air or preconditioned air enters through second air inlet chamber 122, it is first cooled by second surface cooler 128. Similar to first surface cooler 126, second surface cooler 128 also uses refrigerant to reduce the air temperature to a set value. This refrigerant is then mixed with outdoor fresh air and delivered indoors to meet indoor cooling requirements.

[0058] By providing a first surface cooler 126 and a second surface cooler 128, the outdoor fresh air and primary return air can be cooled separately, reducing the temperature of the air entering the room, thereby improving the cooling efficiency of the air conditioning unit. This cooling process removes some moisture and impurities from the air, improving the cleanliness and comfort of the air entering the room. Based on indoor and outdoor environmental conditions and user needs, the control unit can adjust the operating status of the first and second surface coolers 126, 128 (such as on / off, cooling capacity, etc.) to achieve more precise temperature control.

[0059] According to one embodiment of the present invention, a water receiving pan 134 is provided below the first surface cooler 126 and the second surface cooler 128 .

[0060] During the operation of the cooler, especially in cooling mode, due to the low surface temperature, water vapor in the air will condense into water droplets on its surface. If these condensed water are not removed in time, it may have an adverse effect on the performance of the cooler and the indoor environment. Therefore, a water collection tray 134 is provided to collect and discharge these condensed water in time. The design of the water collection tray 134 can ensure that the condensed water will not drip directly into the room, thereby avoiding damage to the indoor environment and equipment caused by water droplets. The water collection tray 134 should be installed directly below the cooler and ensure that it fits tightly with the cooler to ensure that the condensed water can be completely collected and discharged.

[0061] According to an embodiment of the present invention, filters are provided between the air outlet of the first air inlet cavity 118 and the first surface cooler 126 , and between the air outlet of the second air inlet cavity 122 and the second surface cooler 128 .

[0062] A filter is installed between the outlet of the first air inlet chamber 118 and the first surface cooler 126. When outdoor air enters through the first air inlet chamber 118, it is first filtered to remove impurities such as dust, pollen, and particulate matter. A filter is also installed between the outlet of the second air inlet chamber 122 and the second surface cooler 128. When primary return air or pre-conditioned air enters through the second air inlet chamber 122, it is first filtered to ensure air cleanliness.

[0063] According to an embodiment of the present invention, the filter includes a primary filter 130 and a secondary filter 132 . Along the air supply direction, the primary filter 130 is disposed upstream of the secondary filter 132 .

[0064] The primary filter 130, located after the air outlet of the air inlet chamber, is the first line of defense against air entering the system. It is primarily used to capture larger particles, such as dust, hair, and insects, to prevent them from damaging subsequent equipment or affecting the filtration effect.

[0065] The secondary filter 132 is located downstream of the primary filter 130, i.e., at a subsequent position in the air supply direction. The secondary filter 132 is mainly used to capture smaller particles, such as pollen, bacteria, viruses, etc., to further improve the cleanliness of the air.

[0066] By providing multiple filter stages, each filter stage 130 targets particles of a specific size, thereby improving overall filtration efficiency. The primary filter 130 captures large particles, reducing the burden on the secondary filter 132 and enabling it to better perform its filtering function. The presence of the primary filter 130 effectively reduces the number of particles entering the system, minimizing damage to subsequent equipment such as the air cooler, thereby extending the service life of these devices. Through the combined action of multiple filters, the cleanliness of the air delivered to the room is significantly improved, providing users with a healthier and more comfortable indoor environment.

[0067] According to one embodiment of the present invention, a secondary return air port (not shown in the figure) is opened on the secondary return air cavity 102, and a secondary return air valve (not shown in the figure) is provided at the secondary return air port. The secondary return air cavity 102 is arranged between the second air inlet cavity 122 and the air supply cavity 104.

[0068] An opening is provided on the secondary return air cavity 102 to allow the secondary air to enter the cavity. This opening is usually located at an appropriate position in the system to effectively capture and guide the secondary air. A control device is provided at the secondary return air inlet to adjust or control the flow of the secondary air into the cavity. This valve can be opened, closed or adjusted to a specific opening as needed to precisely control the flow of the secondary air. The secondary return air cavity 102 is located between the second air inlet cavity 122 and the air supply cavity 104. This layout allows the secondary air to be collected and processed before being mixed with other fresh air or treated air.

[0069] When the system is running, secondary air enters the secondary return air chamber 102 through the secondary return air inlet. A secondary return air valve adjusts the secondary air flow rate based on system requirements or control strategies. The secondary air then mixes with other fresh air or treated air in the second air inlet chamber 122 before being delivered to the target area through the air supply chamber 104.

[0070] This secondary return air system can be widely used in various occasions requiring air treatment or ventilation, such as office buildings, shopping malls, factories, etc. By precisely controlling the flow rate and mixing ratio of secondary air, the system can optimize air treatment efficiency, improve indoor air quality, and reduce energy consumption and operating costs.

[0071] According to an embodiment of the present invention, the primary return air cavity 100 is disposed between the second air inlet cavity 122 and the air exhaust cavity 106 , and the second air valve 110 is disposed in the second air inlet cavity 122 .

[0072] The primary return air chamber 100 is located between the second air inlet chamber 122 and the exhaust chamber 106. The primary air is collected in the primary return air chamber 100 before being recovered and processed, rather than discharged directly outdoors. A second air valve 110 is located in the second air inlet chamber 122 and is used to control the mixing ratio of fresh air and primary air, or to adjust the air volume of the entire system.

[0073] When the system is in operation, primary air is collected by the primary return air chamber 100. Simultaneously, fresh air enters the second air inlet chamber 122. There, the fresh air mixes with the primary air, and the mixing ratio is adjusted as needed by the second air valve 110. The mixed air is then delivered to the target area, such as an indoor space, through the air supply chamber 104. Unnecessary air is discharged outdoors through the exhaust chamber 106.

[0074] According to one embodiment of the present invention, a humidifier 136 is provided between the air outlet of the first air inlet cavity 118 , the air outlet of the second air inlet cavity 122 and the air supply cavity 104 .

[0075] Humidifier 136 increases the humidity of air passing through the system to meet the humidity requirements of a specific environment. Located between the two air outlets and the air supply chamber 104, humidifier 136 adds water vapor to the passing air, thereby increasing its humidity. Humidifier 136 typically consists of a water reservoir and a humidifying element, which converts water into vapor and releases it into the air.

[0076] When the system is in operation, the first air inlet chamber 118 and the second air inlet chamber 122 draw in fresh air (outdoor air) and primary return air (used indoor air), respectively. These two air streams meet the humidifier 136 at their respective air outlets. The humidifier 136 adds water vapor to the air, increasing its humidity. The humidified air then enters the air supply chamber 104 and is delivered to the target area through the air supply duct.

[0077] According to one embodiment of the present invention, an exhaust valve 138 is provided between the primary return air cavity 100 and the exhaust cavity 106 .

[0078] The exhaust valve 138 is disposed between the primary return air chamber 100 and the exhaust chamber 106 to control the air flow from the primary return air chamber 100 to the exhaust chamber 106. The exhaust valve 138 can be opened, closed, or adjusted to a specific opening as needed to precisely control the amount of indoor air discharged.

[0079] When the system is operating, primary air is collected through the primary return air chamber 100. Based on parameters such as indoor air quality, temperature, and humidity, as well as the system control strategy, the exhaust valve 138 adjusts the air flow from the primary return air chamber 100 to the exhaust chamber 106. If the indoor air quality is poor or the indoor temperature and humidity need to be lowered, the exhaust valve 138 may be opened wider to increase the amount of indoor air discharged. Conversely, if the indoor air quality is good or the indoor temperature and humidity need to be kept stable, the exhaust valve 138 may be opened narrower to reduce the amount of indoor air discharged.

[0080] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A secondary return air conditioning unit, characterized in that: include: An air cavity, wherein an air inlet cavity, a primary air return cavity (100), a secondary air return cavity (102), an air supply cavity (104) and an air exhaust cavity (106) are arranged in the air cavity, the air inlet cavity and the air supply cavity (104) are arranged with a first air valve (108), and a second air valve (110) is arranged between the primary air return cavity (100) and the air inlet cavity; A first air blower (112) is disposed between the air inlet cavity and the air supply cavity (104); A second air supply fan (114) is disposed between the secondary return air cavity (102) and the air supply cavity (104); An exhaust fan (116), disposed in the exhaust cavity (106); A control component, wherein the control component is adapted to adjust the opening and closing of the first air valve (108) and the second air valve (110) based on the operating mode of the air conditioning unit.

2. The secondary return air conditioning unit according to claim 1, characterized in that: The air inlet cavity comprises: A first air inlet cavity (118), wherein an air inlet (120) is provided on the first air inlet cavity (118) and the first air valve (108) is disposed in the first air inlet cavity (118); The second air inlet cavity (122) is arranged adjacent to the first air inlet cavity (118), and a third air valve (124) is arranged between the second air inlet cavity (122) and the first air inlet cavity (118).

3. The secondary return air conditioning unit according to claim 2, characterized in that: A first surface cooler (126) is provided between the air outlet of the first air inlet chamber (118) and the first air blower (112); A second surface cooler (128) is provided between the air outlet of the second air inlet chamber (122) and the second air supply fan (114).

4. The secondary return air conditioning unit according to claim 3, characterized in that: Filters are provided between the air outlet of the first air inlet cavity (118) and the first surface cooler (126), and between the air outlet of the second air inlet cavity (122) and the second surface cooler (128).

5. The secondary return air conditioning unit according to claim 4, characterized in that: The filter comprises a primary filter (130) and a secondary filter (132); along the air supply direction, the primary filter (130) is arranged upstream of the secondary filter (132).

6. The secondary return air conditioning unit according to claim 3, characterized in that: A water receiving pan (134) is provided below the first surface cooler (126) and the second surface cooler (128).

7. The secondary return air conditioning unit according to claim 2, characterized in that: The secondary return air cavity (102) is provided with a secondary return air port, and the secondary return air port is provided with a secondary return air valve. The secondary return air cavity (102) is arranged between the second air inlet cavity (122) and the air supply cavity (104).

8. The secondary return air conditioning unit according to claim 2, characterized in that: The primary return air cavity (100) is arranged between the second air inlet cavity (122) and the air exhaust cavity (106), and the second air valve (110) is arranged in the second air inlet cavity (122).

9. The secondary return air conditioning unit according to any one of claims 2 to 8, characterized in that: A humidifier (136) is provided between the air outlet of the first air inlet cavity (118), the air outlet of the second air inlet cavity (122) and the air supply cavity (104).

10. The secondary return air conditioning unit according to any one of claims 1 to 8, characterized in that: An exhaust valve (138) is provided between the primary return air cavity (100) and the exhaust cavity (106).

Images