Energy-saving central air-conditioning ventilation system

Abstract

The utility model discloses an energy-saving central air conditioner ventilation system which comprises a fresh air system and an exhaust system, and the fresh air system comprises a fresh air inlet pipeline, a fresh air primary efficiency filter box, a fresh air medium efficiency filter box and a fresh air supply pipeline which are sequentially connected along the wind direction. The air exhaust system is characterized in that the air exhaust system comprises an air exhaust inlet pipeline, an air exhaust primary-effect filter box, an air exhaust medium-effect filter box, an air exhaust air collecting box and an air exhaust outlet pipeline which are sequentially connected along the air direction, and further comprises a fresh air exhaust heat exchanger which comprises two groups of air inlet and outlet channels; wherein an air inlet A of one group of air inlet and outlet ducts is connected with the fresh air primary-effect filter box, an air outlet A of one group of air inlet and outlet ducts is connected with the fresh air medium-effect filter box, an air inlet B of the other group of air inlet and outlet ducts is connected with the exhaust medium-effect filter box, an air outlet B of the other group of air inlet and outlet ducts is connected with the exhaust air collecting box, and the two groups of air inlet and outlet ducts exchange heat in the fresh air exhaust heat exchanger. The ventilation system is high in integration degree and low in energy consumption.

Description

Technical Field

[0001] The utility model relates to the field of air conditioning and ventilation engineering, in particular to a low-energy-consumption and energy-saving central air conditioning and ventilation system. Background Art

[0002] Currently, most public medical and health buildings use centralized air conditioning and ventilation systems to regulate indoor air temperature. Some use full return air operation for energy conservation, while others use full fresh air operation to meet indoor fresh air needs. Although the former saves energy, it cannot guarantee the necessary indoor fresh air demand. While the latter guarantees indoor fresh air demand, it consumes relatively higher energy. Therefore, in recent years, to meet the demand for indoor fresh air and reduce energy consumption, many hospitals have chosen to use fresh air units with sensible heat recovery or full heat recovery when designing and constructing general diagnosis and wards. However, most current fresh air units with sensible heat recovery or full heat recovery cannot operate with return air. Although these fresh air units are equipped with heat recovery devices in the fresh air and exhaust plenum, they still consume more energy than those using direct return air operation.

[0003] Chinese patent CN114294749A discloses a hospital building ventilation and air conditioning circulation purification device, specifically disclosing a connected solid gas washing device and an air filter device. The input end of the solid gas washing device is connected to the exhaust port of the hospital building's ventilation area, and the output end of the air filter device is connected to the air inlet of the hospital building's ventilation area. The solid gas washing device is used to purify the primary exhaust air with solid particles and output secondary exhaust air to the air filter device, which is used to filter the secondary exhaust air and re-deliver clean air to the hospital building's ventilation area. An exhaust valve and an exhaust fan are sequentially arranged between the exhaust port and the solid gas washing device. The solid gas washing device and the air filter device are connected by an air pipe and are equipped with an on-off valve. A negative pressure fan is installed between the air filter device and the air inlet. The above patent only adds a solid gas washing device and an air filter device to the exhaust port of the existing hospital building ventilation and air conditioning, and continues to pass the filtered exhaust air into the air inlet to form a return air operation. However, the above patents still have problems such as separate units, low system structure integration, and low heat exchange efficiency. Utility Model Content

[0004] The purpose of the utility model is to provide a central air-conditioning and ventilation system with low energy consumption and high integration.

[0005] The purpose of the utility model is achieved through the following technical solutions: an energy-saving central air-conditioning ventilation system, including a fresh air system and an exhaust system, the fresh air system including a fresh air inlet duct, a fresh air primary filter box, a fresh air medium filter box and a fresh air supply duct connected in sequence in the downwind direction, characterized in that: the exhaust system includes an exhaust air inlet duct, an exhaust primary filter box, an exhaust medium filter box, an exhaust collecting box and an exhaust outlet duct connected in sequence in the downwind direction, and also includes a fresh exhaust heat exchanger, the fresh exhaust heat exchanger includes two groups of inlet and outlet ducts, the air inlet A of one group of inlet and outlet ducts is connected to the fresh air primary filter box, and the air outlet A is connected to the fresh air medium filter box, the air inlet B of the other group of inlet and outlet ducts is connected to the exhaust medium filter box, and the air outlet B is connected to the exhaust collecting box, and the two groups of inlet and outlet ducts exchange heat in the fresh air exhaust heat exchanger. The central air conditioning and ventilation system employs the aforementioned configuration, adding a primary and secondary filter during the exhaust process to filter the exhaust air twice. This results in a higher degree of cleanliness for the filtered exhaust air, significantly reducing the blockage probability and cleaning frequency of the new exhaust fan, improving the heat exchange efficiency of the new exhaust heat exchanger, and reducing its energy consumption. Furthermore, the two filter boxes are directly incorporated into the exhaust system, resulting in a high degree of integration.

[0006] In order to further realize the multi-mode operation of the central air conditioning ventilation system, the central air conditioning ventilation system also includes an exhaust return air box located between the exhaust medium efficiency filter box and the fresh exhaust air heat exchanger, the air inlet of the exhaust return air box is connected to the exhaust medium efficiency filter box, the air outlet of the exhaust return air box is connected to the fresh exhaust air heat exchanger, and a return air circulation valve is provided in the exhaust return air box, and the return air circulation valve is connected to the fresh air medium efficiency filter box. With the above arrangement, the exhaust air that has been filtered twice can be introduced into the fresh air system as return air, reducing the operating energy consumption of the fresh air system. By building a return air circulation valve into the central air conditioning ventilation system, multiple operating modes such as fresh air operation, full exhaust operation, full supply and full exhaust operation, full return air operation, partial return air + fresh air operation, etc. can be realized.

[0007] Furthermore, the exhaust primary filter box is integrated with the exhaust air inlet duct, an exhaust temperature sensor and an exhaust primary filter are provided in the exhaust air inlet duct along the wind direction, a third wind resistance pressure difference sensor is connected to both ends of the exhaust primary filter, an exhaust medium efficiency filter is provided in the exhaust medium efficiency filter box, and a fourth wind resistance pressure difference sensor is connected to both ends of the exhaust medium efficiency filter. Integrating the exhaust primary filter box with the exhaust air inlet duct improves the integration of the system structure, and through the provision of the third and fourth wind resistance pressure difference sensors, an alarm can be issued when the wind resistance pressure difference sensor detects that the pressure difference exceeds the set threshold, reminding the staff to clean or replace the filter.

[0008] Furthermore, an exhaust fan is provided at the air outlet in the exhaust medium-efficiency filter box, an exhaust air valve is provided in the exhaust air outlet duct, and the exhaust fan is linked to the exhaust air valve.

[0009] Furthermore, a fresh air inlet temperature sensor and a fresh air inlet valve are provided in the fresh air inlet duct along the wind direction.

[0010] Furthermore, the fresh air primary filter box is provided with a fresh air primary filter, and both ends of the fresh air primary filter are connected to a first wind resistance pressure differential sensor. The fresh air intermediate filter box is provided with a fresh air intermediate filter, and both ends of the fresh air intermediate filter are connected to a second wind resistance pressure differential sensor. The arrangement of the first wind resistance pressure differential sensor and the second wind resistance pressure differential sensor can generate an alarm when the wind resistance pressure differential sensor detects that the pressure differential exceeds a set threshold, reminding staff to clean or replace the filter.

[0011] Preferably, the fresh air medium efficiency filter box is further provided with an air conditioning heat exchange mechanism, the air conditioning heat exchange mechanism being located after the fresh air medium efficiency filter, and the return air circulation valve being connected between the fresh air medium efficiency filter of the fresh air medium efficiency filter box and the air conditioning heat exchange mechanism. With this arrangement, when return air is used, the return air undergoes a second filtration, which can improve cleanliness, thereby reducing the probability of blockage and cleaning frequency of the air conditioning heat exchange mechanism, improving the heat exchange efficiency of the air conditioning heat exchange mechanism, and saving energy consumption.

[0012] Preferably, the air-conditioning heat exchange mechanism includes an air-conditioning heat exchange coil and a condensate accumulation pan arranged in the fresh air medium-efficiency filter box, the air-conditioning heat exchange coil includes heat exchange fins and an air-conditioning water circulation pipe passing through the heat exchange fins, the water inlet pipe of the air-conditioning water circulation pipe is located outside the fresh air medium-efficiency filter box and is provided with an inlet valve, a Y-type filter and a proportional flow regulating valve in sequence along the direction of water flow, the water outlet pipe of the air-conditioning water circulation pipe is located outside the fresh air medium-efficiency filter box and is provided with an air-conditioning water temperature sensor and an outlet valve in sequence along the direction of water flow, and the proportional flow regulating valve is linked to the exhaust air temperature sensor; the condensate accumulation pan is connected to a condensate outlet pipe, and a condensate valve is provided on the condensate outlet pipe.

[0013] Preferably, a fresh air blower is further provided at the air outlet of the fresh air medium-efficiency filter box, the fresh air blower is linked to the fresh air inlet valve, and a fresh air supply temperature sensor is provided on the fresh air supply duct.

[0014] In order to further reduce noise and dynamic pressure loss, static pressure boxes are provided at the front ends of the fresh air inlet duct and the exhaust air inlet duct. Beneficial effects

[0015] This new utility model utilizes a fresh air heat exchanger to exchange heat between exhaust and fresh air in a full-supply, full-exhaust mode, reducing the heat exchange load required by the air conditioning heat exchange coil and lowering energy consumption. Furthermore, the exhaust air, having undergone two filtration steps, is more clean, preventing rapid clogging of the fresh air heat exchanger, improving heat exchange efficiency, and achieving energy savings.

[0016] This new system integrates an exhaust return air box and a return air circulation valve, allowing the exhaust air, which has been filtered twice, to be introduced into the fresh air system. After cooling or heating through the air conditioning heat exchange mechanism, it is then delivered to the room, achieving full or partial return air operation. Furthermore, this new system has a high degree of integration and can realize multiple operating modes.

[0017] 3. The utility model monitors the pressure difference before and after the filter through four windage pressure difference sensors, and can clean or replace the filter in time after it is dirty and clogged, thereby indirectly improving the heat exchange efficiency and reducing energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings of the present invention are described as follows.

[0019] Figure 1 This is a simplified structural diagram of the central air conditioning and ventilation system in Example 1;

[0020] Figure 2 This is a simplified structural diagram of the central air conditioning and ventilation system in Example 2.

[0021] Explanation of reference numbers: fresh air inlet duct 1, fresh air primary filter box 2, fresh air medium efficiency filter box 3, fresh air supply duct 4, fresh air inlet temperature sensor 5, fresh air inlet valve 6, fresh air primary filter 7, first wind resistance pressure difference sensor 8, fresh air medium efficiency filter 9, second wind resistance pressure difference sensor 10, air conditioning heat exchange mechanism 11, fresh air fan 12, air conditioning heat exchange coil 13, condensate water pan 14, air conditioning water circulation pipe 15, water inlet pipe 16, water inlet valve 17, Y-type filter 18, proportional flow control valve 19, water outlet pipe 20, air conditioning water temperature sensor 21, water outlet valve 22, condensate outlet pipe 23, condensate Water valve 24, fresh air supply temperature sensor 25, exhaust air inlet duct 26, exhaust medium efficiency filter box 27, exhaust return air box 28, exhaust air collecting box 29, exhaust air outlet duct 30, exhaust temperature sensor 31, exhaust primary filter 32, third wind resistance pressure difference sensor 33, exhaust medium efficiency filter 34, fourth wind resistance pressure difference sensor 35, exhaust fan 36, return air circulation valve 37, exhaust air valve 38, fresh exhaust air heat exchanger 39, ultraviolet lamp sterilization bellows 40, electrostatic air purification bellows 41, ultraviolet lamp 42, lampshade 43, cover plate 44, bolts 45, spoiler wind deflector 46, electrostatic air purification device 47. DETAILED DESCRIPTION

[0022] The embodiments of the present application are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended only to explain the present application and are not to be construed as limiting the present application. On the contrary, the embodiments of the present application include all variations, modifications, and equivalents that fall within the spirit and scope of the appended claims.

[0023] Example 1: Figure 1 As shown, this embodiment provides a central air conditioning and ventilation system, including a fresh air system and an exhaust system.

[0024] The fresh air system includes a fresh air inlet duct 1, a fresh air primary filter box 2, a fresh air medium filter box 3, and a fresh air supply duct 4, which are connected in sequence along the wind direction. A fresh air inlet temperature sensor 5 and a fresh air inlet valve 6 are sequentially arranged in the fresh air inlet duct 1 in the direction along the wind. A fresh air primary filter 7 is arranged in the fresh air primary filter box, and a first wind resistance pressure difference sensor 8 is connected to both ends of the fresh air primary filter. A fresh air medium filter 9 is arranged in the fresh air medium filter box, and a second wind resistance pressure difference sensor 10 is connected to both ends of the fresh air medium filter. An air conditioning heat exchange mechanism 11 is also arranged in the fresh air medium filter box after the fresh air medium filter, and a fresh air fan 12 is also arranged at the air outlet of the fresh air medium filter box. The fresh air fan discharges the fresh air that has been filtered / filtered and heated / filtered and cooled in the fresh air medium filter box into the fresh air supply duct. The air conditioning heat exchange mechanism includes an air conditioning heat exchange coil 13 and a condensate collection pan 14 disposed within the fresh air medium-efficiency filter box. The air conditioning heat exchange coil includes heat exchange fins and an air conditioning water circulation pipe 15 passing through the heat exchange fins. The air conditioning water circulation pipe's inlet pipe 16 is located outside the box and is sequentially provided with an inlet valve 17, a Y-type filter 18, and a proportional flow control valve 19 in the direction of water flow. The air conditioning water circulation pipe's outlet pipe 20 is located outside the box and is sequentially provided with an air conditioning water temperature sensor 21 and an outlet valve 22 in the direction of water flow. The condensate collection pan is connected to a condensate outlet pipe 23, which is provided with a condensate valve 24. A fresh air supply temperature sensor 25 is provided within the fresh air supply duct.

[0025] The exhaust system includes an exhaust air inlet duct 26, an exhaust primary filter box, an exhaust medium filter box 27, an exhaust return air box 28, an exhaust air collecting box 29 and an exhaust air outlet duct 30, which are connected in sequence along the wind direction. The exhaust air inlet duct and the exhaust primary filter box can be two mechanisms or integrated into one. In this embodiment, the exhaust primary filter box is integrated into the exhaust air inlet duct, and the exhaust air inlet duct is provided with an exhaust temperature sensor 31 and an exhaust primary filter 32 along the wind box, and a third wind resistance pressure difference sensor 33 is connected to both ends of the exhaust primary filter. An exhaust medium filter 34 is provided in the exhaust medium filter box, and a fourth wind resistance pressure difference sensor 35 is connected to both ends of the exhaust medium filter. An exhaust fan 36 is provided at the air outlet of the exhaust medium-efficiency filter box. The exhaust fan discharges the return air after the second filtration in the exhaust medium-efficiency filter box into the exhaust return air box. The exhaust return air box is provided with a return air circulation valve 37. The return air circulation valve is connected to the fresh air medium-efficiency filter box and is located between the fresh air medium-efficiency filter and the air conditioning heat exchange mechanism. When the return air circulation valve is opened, the return air after the second filtration in the exhaust return air box can be introduced into the fresh air medium-efficiency filter box and discharged as fresh air. An exhaust air valve 38 is provided in the exhaust air outlet duct.

[0026] In addition, in this embodiment, a fresh air exhaust heat exchanger 39 is also provided, and the fresh air exhaust heat exchanger includes two groups of inlet and outlet air ducts, wherein the air inlet A of one group of inlet and outlet air ducts is connected to the fresh air primary efficiency filter box, and the air outlet A is connected to the fresh air medium efficiency filter box, and the air inlet B of the other group of inlet and outlet air ducts is connected to the exhaust air return box, and the air outlet B is connected to the exhaust air collecting box. The two groups of inlet and outlet air ducts perform heat exchange in the fresh air exhaust heat exchanger.

[0027] As another implementation in this embodiment, the inner walls of the fresh air primary filter box, exhaust return air box and exhaust air collecting box are provided with sound-absorbing materials / structures, and the front ends of the fresh air inlet duct and the exhaust air inlet duct are provided with static pressure boxes.

[0028] In the central air conditioning and ventilation system of this embodiment, the fresh air blower is linked to the fresh air inlet valve. When the control system remotely activates the fresh air blower, the fresh air inlet valve automatically opens before the fresh air blower begins operation. Conversely, the fresh air blower is shut down before the fresh air inlet valve. When the fresh air system is activated, outdoor fresh air enters through the fresh air inlet duct, passes through the fresh air inlet valve, and enters the fresh air primary filter bellows. After being filtered by the primary filter, it enters the fresh air heat exchanger for heat exchange with the exhaust air. After heat exchange with the exhaust air in the fresh air heat exchanger, the fresh air enters the fresh air medium efficiency filter box, where it undergoes secondary filtration by the fresh air medium efficiency filter. The fresh air filtered by the fresh air medium efficiency filter enters the air conditioning heat exchange coil for heating or cooling, and is finally delivered to the room by the fresh air blower through the fresh air duct. Furthermore, the proportional flow control valve in this embodiment is linked to the exhaust air temperature sensor to adjust the opening of the proportional flow control valve based on the exhaust air temperature, thereby regulating the temperature of the fresh air delivered to the room.

[0029] When the fresh air primary filter becomes clogged, the pressure differential between the front and rear of the filter increases. When the first wind resistance pressure differential sensor detects that the pressure differential exceeds the set threshold, an alarm is generated in the control system, thereby reminding the staff to clean or replace the fresh air primary filter in a timely manner. When the fresh air medium efficiency filter becomes clogged, the second wind resistance pressure differential sensor detects that the pressure differential exceeds the set threshold, thereby reminding the staff to replace the fresh air medium efficiency filter in a timely manner.

[0030] The exhaust fan is linked to the exhaust valve. When the control system remotely activates the exhaust fan, the exhaust valve is automatically opened first, and then the exhaust fan is started. Conversely, the exhaust fan is shut down first, and then the exhaust valve is closed. When the exhaust system is activated, indoor return air enters through the exhaust air inlet duct and is filtered for the first time by the exhaust primary filter. It then enters the exhaust medium efficiency filter box and undergoes a secondary filtration by the exhaust medium efficiency filter. After the secondary filtration, the exhaust air exchanges heat with the fresh air through the new exhaust heat exchanger and is discharged outdoors through the exhaust outlet duct.

[0031] When the exhaust primary filter becomes clogged, the pressure differential across the filter increases. When the third wind resistance pressure differential sensor detects that the pressure differential exceeds a set threshold, an alarm is generated in the control system, thereby reminding the staff to replace the exhaust primary filter in a timely manner. When the exhaust secondary filter becomes clogged, the fourth wind resistance pressure differential sensor detects that the pressure differential exceeds a set threshold, thereby reminding the staff to clean or replace the exhaust secondary filter in a timely manner.

[0032] As an option, the fresh air inlet temperature sensor in this embodiment adopts a Class 1 precision T-type thermocouple, and the air-conditioning water temperature sensor adopts a Class 1 precision T-type armored thermocouple.

[0033] This embodiment utilizes a fresh air return heat exchanger to exchange heat between return air and fresh air, reducing the heat exchange load required by the air conditioning heat exchange coil and lowering energy consumption. Furthermore, the twice-filtered return air passing through the heat exchanger prevents dust accumulation and clogging of the fresh exhaust heat exchanger caused by prolonged exhaust operation, thereby ensuring heat exchange efficiency. Furthermore, this embodiment uses four windage pressure differential sensors to monitor the pressure differential across the filter, enabling timely cleaning or replacement of clogged filters, thereby indirectly improving heat exchange efficiency.

[0034] Furthermore, the exhaust system in this embodiment also includes a built-in exhaust return air box and return air circulation valve, enabling the central air conditioning and ventilation system of this embodiment to implement multiple operating modes, such as a standalone fresh air operating mode, a fresh air air conditioning operating mode, a standalone exhaust mode, a full fresh air and exhaust mode, a partial return air + fresh air mode with the return air circulation valve open, and a full return air mode with the return air circulation valve open. Furthermore, in the partial return air or full return air modes, the exhaust air undergoes two filtration steps, resulting in a high degree of cleanliness, ensuring the quality of the return air, reducing the operating heat load requirement of the air conditioning heat exchange mechanism, and lowering energy consumption.

[0035] In addition, in this embodiment, only one supply fan and one exhaust fan are provided in the entire central air-conditioning and ventilation system. For the existing central air-conditioning and ventilation systems that only have heat recovery or return air operation, they can be simply modified so that the existing air-conditioning system can also achieve the energy-saving air-conditioning system in this embodiment.

[0036] As an option, the air conditioning heat exchange mechanism in this embodiment is a 2-pipe air conditioning water system. For areas with constant temperature and humidity or high air conditioning requirements, a 4-pipe air conditioning water system can be adopted.

[0037] Example 2: Figure 2 As shown, this embodiment provides a central air conditioning and ventilation system, including a fresh air system and an exhaust system.

[0038] The fresh air system includes a fresh air inlet duct 1, a fresh air primary filter box 2, a fresh air medium filter box 3, and a fresh air supply duct 4, which are connected in sequence along the wind direction. A fresh air inlet temperature sensor 5 and a fresh air inlet valve 6 are sequentially arranged in the fresh air inlet duct along the wind direction. A fresh air primary filter 7 is arranged in the fresh air primary filter box, and a first wind resistance pressure difference sensor 8 is connected to both ends of the fresh air primary filter. A fresh air medium filter 9 is arranged in the fresh air medium filter box, and a second wind resistance pressure difference sensor 10 is connected to both ends of the fresh air medium filter. An air conditioning heat exchange mechanism 11 is also arranged in the fresh air medium filter box after the fresh air medium filter, and a fresh air fan 12 is also arranged at the air outlet of the fresh air medium filter box. The fresh air fan discharges the fresh air that has been filtered / filtered and heated / filtered and cooled in the fresh air medium filter box into the fresh air supply duct. The air conditioning heat exchange mechanism includes an air conditioning heat exchange coil 13 and a condensate collection pan 14 disposed within the fresh air medium-efficiency filter box. The air conditioning heat exchange coil includes heat exchange fins and an air conditioning water circulation pipe 15 passing through the heat exchange fins. The air conditioning water circulation pipe's inlet pipe 16 is located outside the box and is sequentially provided with an inlet valve 17, a Y-type filter 18, and a proportional flow control valve 19 in the direction of water flow. The air conditioning water circulation pipe's outlet pipe 20 is located outside the box and is sequentially provided with an air conditioning water temperature sensor 21 and an outlet valve 22 in the direction of water flow. The condensate collection pan is connected to a condensate outlet pipe 23, which is provided with a condensate valve 24. A fresh air supply temperature sensor 25 is provided within the fresh air supply duct.

[0039] The exhaust system includes an exhaust air inlet duct 26, an exhaust primary filter box, an exhaust sterilization and purification mechanism, an exhaust intermediate filter box 27, an exhaust return air box 28, an exhaust air collecting box 29 and an exhaust air outlet duct 30, which are connected in sequence along the wind direction. The exhaust air inlet duct and the exhaust primary filter box can be two mechanisms or integrated into one. In this embodiment, the exhaust primary filter box is integrated into the exhaust air inlet duct, and the exhaust air inlet duct is provided with an exhaust air temperature sensor 31 and an exhaust primary filter 32 along the wind direction. A third wind resistance pressure difference sensor 33 is connected at both ends of the exhaust primary filter. An exhaust intermediate filter 34 is provided in the exhaust intermediate filter box, and a fourth wind resistance pressure difference sensor 35 is connected at both ends of the exhaust intermediate filter. An exhaust fan 36 is provided at the air outlet of the exhaust intermediate filter box, and the exhaust fan discharges the return air filtered in the exhaust intermediate filter box into the exhaust return air box. The exhaust return air box is provided with an exhaust circulation air valve 37, which is connected to the fresh air medium efficiency filter box and is located between the fresh air medium efficiency filter and the air conditioning heat exchange coil. The exhaust air outlet duct is provided with an exhaust air valve 38.

[0040] In addition, in this embodiment, a fresh air exhaust heat exchanger 39 is also provided, and the fresh air exhaust heat exchanger includes two groups of inlet and outlet air ducts, wherein the air inlet A of one group of inlet and outlet air ducts is connected to the fresh air primary efficiency filter box, and the air outlet A is connected to the fresh air medium efficiency filter box, and the air inlet B of the other group of inlet and outlet air ducts is connected to the exhaust air return box, and the air outlet B is connected to the exhaust air collecting box. The two groups of inlet and outlet air ducts perform heat exchange in the fresh air exhaust heat exchanger.

[0041] The exhaust sterilization and purification mechanism in this embodiment includes an ultraviolet lamp sterilization bellows 40 and an electrostatic air purification bellows 41 connected in the downwind direction. The air inlet of the ultraviolet lamp sterilization bellows is connected to the exhaust air inlet duct, and the air outlet is connected to the air inlet of the electrostatic air purification device, and the air outlet of the electrostatic air purification device is connected to the air inlet of the exhaust medium efficiency filter box. The opposite side walls in the downwind direction of the ultraviolet lamp sterilization bellows (from Figure 2 The direction shown in the figure can be the upper and lower side walls or the front and rear side walls) are respectively provided with an ultraviolet lamp 42, a lampshade 43 is provided outside the ultraviolet lamp, and a cover plate 44 is provided on the side wall where the ultraviolet lamp is installed. The cover plate covers the ultraviolet lamp and is detachably connected to the side wall. In this embodiment, the cover plate is connected to the side wall by bolts 45. An ultraviolet sterilization indicator light and an ultraviolet sterilization lamp fault warning light are also provided outside the ultraviolet sterilization bellows to remind maintenance personnel not to open the cover plate for maintenance during ultraviolet sterilization, and to repair the ultraviolet lamp in time after a failure. The ultraviolet sterilization lamp is externally mounted and can be disassembled, repaired and replaced by opening the external cover plate, making subsequent repair and maintenance more convenient.

[0042] As another implementation in this embodiment, the inner wall of the air inlet side and the inner wall of the air outlet side of the ultraviolet lamp sterilization bellows are respectively provided with a spoiler windshield 46, and the two spoiler windshields are arranged in parallel and staggered. The spoiler windshield A located on the inner wall of the air inlet side forms an acute angle with the air inlet of the ultraviolet lamp sterilization bellows, and the spoiler windshield B located on the inner wall of the air outlet side forms an acute angle with the air outlet of the ultraviolet lamp sterilization bellows. The spoiler windshield makes the return air in the ultraviolet lamp sterilization bellows more turbulent, the airflow stays in the ultraviolet lamp sterilization bellows longer, and the sterilization effect is more ideal. An electrostatic air purification device 47 is installed in the electrostatic air purification bellows. The electrostatic air purification device is an existing device that can be purchased directly on the market, and its structure will not be described in detail here. The return air after ultraviolet lamp sterilization and electrostatic air purification is filtered again with medium efficiency, and the filtering effect is better.

[0043] As another implementation of this embodiment, the inner walls of the fresh air primary filter box, exhaust return air box and exhaust air collecting box are provided with sound-absorbing materials / structures, and the front ends of the fresh air inlet duct and the exhaust air inlet duct are provided with static pressure boxes.

[0044] The central air conditioning and ventilation system of this embodiment has multiple working modes and is suitable for a variety of working scenarios. In this embodiment, an exhaust sterilization and purification mechanism is set between the primary filter box and the medium efficiency filter box of the exhaust system, an exhaust return air box is set after the exhaust medium efficiency filter box, and a return air circulation valve connected to the fresh air medium efficiency filter box is set in the exhaust return air box. By opening and closing the return air circulation valve and the exhaust sterilization and purification mechanism, a central air conditioning and ventilation system with multiple working modes can be provided for public health buildings, including 1. Full supply and full exhaust working mode under non-special circumstances: the exhaust sterilization and purification mechanism and the return air circulation valve are closed at the same time, and the exhaust air is directly discharged to the outside after heat exchange with the fresh air in the fresh exhaust heat exchanger. That is, the fresh air system and the exhaust air system work separately; 2. Full supply and full exhaust working mode under special circumstances: the exhaust air sterilization and purification mechanism is opened and the return air circulation valve is closed. In this way, the exhaust return air is filtered and sterilized and purified twice and is heat exchanged with the fresh air in the fresh exhaust air heat exchanger before being discharged to the outside. It is suitable for use in respiratory infectious disease areas or when public health events such as SARS and new crown occur. 3. Partial return air + fresh air working mode under non-special circumstances: In order to meet the comprehensive ventilation and energy-saving needs, the circulating air valve can be appropriately adjusted to partially open (the exhaust air sterilization and purification mechanism is closed), and the fresh air valve and the exhaust air valve are fully open. At this time, part of the return air will enter the fresh air medium efficiency filter box and mix with the fresh air, and part of the return air will be discharged to the outside after heat exchange with the fresh air through the fresh exhaust air heat exchanger. This mode can not only meet the indoor fresh air ventilation needs, but also partially utilize the return air for operation, which is more energy-efficient than full supply and full exhaust relying solely on the fresh exhaust air heat exchanger for heat exchange. 4. Partial return air + fresh air working mode under special circumstances: The exhaust air sterilization and purification mechanism is turned on, and the circulating air valve is appropriately adjusted to partially open, and the fresh air valve and exhaust valve are fully opened. At this time, part of the return air will enter the fresh air medium efficiency filter box and mix with the fresh air, and part of the return air will be discharged to the outside after heat exchange with the fresh air through the fresh exhaust air heat exchanger. This mode can not only meet the indoor fresh air ventilation needs, but also because of the partial utilization of return air, it is more energy-efficient than full supply and full exhaust relying solely on the fresh exhaust air heat exchanger for heat exchange. 5. Full return air mode under non-special circumstances: The return air circulation valve is opened, and the exhaust air sterilization and purification mechanism is closed. In this way, the exhaust return air is filtered twice and then sent to the fresh air medium efficiency filter box through the return air circulation valve, and is re-sent into the room as fresh air. The return air cleanliness is high, which can ensure the return air quality, and can reduce the operating heat load demand of the air conditioning heat exchange mechanism and reduce operating energy consumption. 6. Full return air mode under special circumstances: the return air circulation valve and the exhaust air sterilization and purification mechanism are opened, and the fresh air inlet valve is closed. In this way, the exhaust return air is filtered and sterilized and purified twice and then sent into the fresh air medium efficiency filter box through the return air circulation valve, and is re-sent into the room as fresh air.This also reduces the heat load demand of the air conditioning heat exchange mechanism, lowering energy consumption. Furthermore, the return air undergoes two rounds of filtration and sterilization, making it very clean and suitable for use in respiratory infectious disease areas or during public health events such as SARS and COVID-19, without the risk of infection if the air is discharged outdoors. Furthermore, the fresh air system or the exhaust system can be activated separately, and different operating modes can be matched to the air conditioning heat exchange mechanism, the heating function, or the cooling function, depending on the temperature inside the building.

[0045] The central air conditioning and ventilation system of this embodiment is particularly suitable for medical and health public buildings that combine peacetime and wartime use, or new buildings housing respiratory infectious wards, and can operate safely and reliably during public health events involving respiratory infections. For example, when public health events such as COVID-19 and SARS occur, not only can the system be operated in a full-supply, full-exhaust mode under special circumstances, but it can also be operated in a full-return air mode for energy-saving purposes under special circumstances. Furthermore, the central air conditioning system can be operated with low energy consumption and high safety.

[0046] Furthermore, the central air conditioning ventilation system of this embodiment has low energy consumption and high thermal efficiency. First, in this embodiment, the return air heat exchanger is used to allow the return air and the fresh air to exchange heat in the full supply and full exhaust working mode, which can reduce the air conditioning heat exchange load demand of the air conditioning heat exchange mechanism and reduce energy consumption. Second, in the present invention, the exhaust air sterilization and purification mechanism is embedded between the exhaust air primary filter bellows and the exhaust air intermediate filter bellows. This can not only reduce the dust accumulation rate of the return air dust in the electrostatic purification device and reduce the cleaning and maintenance frequency of the electrostatic purification device, but also slow down the dirt clogging rate of the exhaust air intermediate filter. Moreover, the return air after two filtrations, sterilizations and purifications has high cleanliness, avoiding the dust accumulation and dirt clogging of the new exhaust air heat exchanger due to long-term exhaust operation in the full supply and full exhaust working mode, thereby ensuring the heat exchange efficiency of the new exhaust air heat exchanger. Third, the return air after two filtrations, sterilizations and purifications has high cleanliness and good sterilization effect, which can avoid the rapid dirt clogging of the air conditioning heat exchange coil in the full return air operation mode, improve the heat exchange efficiency, and achieve the purpose of energy saving, safety and reliability.

[0047] In this embodiment, only one supply fan and one exhaust fan are provided in the entire central air-conditioning and ventilation system. For the existing central air-conditioning and ventilation system which only has heat recovery or return air operation, it can be simply modified so that the existing air-conditioning system can also realize the multi-mode energy-saving air-conditioning system of the present invention.

[0048] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not limiting. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that various changes can be made in form and detail without departing from the scope defined by the claims of the present invention.

Claims

1. An energy-saving central air conditioning and ventilation system, comprising a fresh air system and an exhaust system, wherein the fresh air system comprises a fresh air inlet duct, a fresh air primary filter box, a fresh air medium filter box, and a fresh air supply duct connected in sequence along the wind direction, characterized in that: The exhaust system includes an exhaust air inlet duct, an exhaust primary filter box, an exhaust medium filter box, an exhaust air collecting box and an exhaust air outlet duct connected in sequence in the downwind direction, and also includes a new exhaust air heat exchanger. The new exhaust air heat exchanger includes two groups of inlet and outlet air ducts, wherein the air inlet A of one group of inlet and outlet air ducts is connected to the fresh air primary filter box, and the air outlet A is connected to the fresh air medium filter box, and the air inlet B of the other group of inlet and outlet air ducts is connected to the exhaust medium filter box, and the air outlet B is connected to the exhaust air collecting box. The two groups of inlet and outlet air ducts exchange heat in the new exhaust air heat exchanger.

2. The energy-saving central air-conditioning and ventilation system according to claim 1, characterized in that: The exhaust system also includes an exhaust return air box located between the exhaust medium efficiency filter box and the fresh exhaust air heat exchanger. The air inlet of the exhaust return air box is connected to the exhaust medium efficiency filter box, and the air outlet of the exhaust return air box is connected to the fresh exhaust air heat exchanger. A return air circulation valve is provided in the exhaust return air box, and the return air circulation valve is connected to the fresh air medium efficiency filter box.

3. The energy-saving central air-conditioning and ventilation system according to claim 2, characterized in that: The exhaust primary filter box is integrated with the exhaust air inlet duct, an exhaust temperature sensor and an exhaust primary filter are arranged in the exhaust air inlet duct along the wind direction, and a third wind resistance pressure difference sensor is connected to both ends of the exhaust primary filter. An exhaust medium efficiency filter is arranged in the exhaust medium efficiency filter box, and a fourth wind resistance pressure difference sensor is connected to both ends of the exhaust medium efficiency filter.

4. The energy-saving central air-conditioning and ventilation system according to claim 3, characterized in that: An exhaust fan is provided at the air outlet of the exhaust medium-efficiency filter box, an exhaust air valve is provided in the exhaust air outlet duct, and the exhaust fan is linked to the exhaust air valve.

5. The energy-saving central air-conditioning and ventilation system according to claim 3 or 4, characterized in that: A fresh air inlet temperature sensor and a fresh air inlet valve are arranged in the fresh air inlet duct along the wind direction.

6. The energy-saving central air-conditioning and ventilation system according to claim 5, characterized in that: A fresh air primary filter is provided in the fresh air primary filter box, and the two ends of the fresh air primary filter are connected to a first wind resistance pressure difference sensor. A fresh air medium efficiency filter is provided in the fresh air medium efficiency filter box, and the two ends of the fresh air medium efficiency filter are connected to a second wind resistance pressure difference sensor.

7. The energy-saving central air-conditioning and ventilation system according to claim 6, characterized in that: The fresh air medium efficiency filter box is also provided with an air conditioning heat exchange mechanism, which is located after the fresh air medium efficiency filter, and the return air circulation valve is connected between the fresh air medium efficiency filter of the fresh air medium efficiency filter box and the air conditioning heat exchange mechanism.

8. The energy-saving central air-conditioning and ventilation system according to claim 7, characterized in that: The air-conditioning heat exchange mechanism includes an air-conditioning heat exchange coil and a condensate accumulation pan arranged in the fresh air medium-efficiency filter box. The air-conditioning heat exchange coil includes heat exchange fins and an air-conditioning water circulation pipe passing through the heat exchange fins. The water inlet pipe of the air-conditioning water circulation pipe is located outside the fresh air medium-efficiency filter box and is provided with an inlet valve, a Y-type filter and a proportional flow regulating valve in sequence along the direction of water flow. The water outlet pipe of the air-conditioning water circulation pipe is located outside the fresh air medium-efficiency filter box and is provided with an air-conditioning water temperature sensor and an outlet valve in sequence along the direction of water flow. The proportional flow regulating valve is linked to the exhaust air temperature sensor; the condensate accumulation pan is connected to a condensate outlet pipe, and a condensate valve is provided on the condensate outlet pipe.

9. The energy-saving central air-conditioning and ventilation system according to claim 6, 7 or 8, characterized in that: A fresh air blower is also provided at the air outlet of the fresh air medium-efficiency filter box, the fresh air blower is linked to the fresh air inlet valve, and a fresh air supply temperature sensor is provided on the fresh air supply duct.

10. The energy-saving central air-conditioning and ventilation system according to claim 1, characterized in that: The front ends of the fresh air inlet duct and the exhaust air inlet duct are both provided with static pressure boxes.

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