Multi-mode energy-saving central air-conditioning ventilation system

Abstract

The invention discloses a multi-mode 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 in the downwind 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 an air exhaust sterilization and purification mechanism which is communicated front and back is further arranged between the air exhaust primary-effect filter box and the air exhaust medium-effect filter box; an exhaust air return box communicated in the front-back direction is further arranged between the exhaust air medium-efficiency filter box and the exhaust air collecting box, and an air return circulating valve is arranged in the exhaust air return box and communicated with the fresh air medium-efficiency filter box. The central air-conditioning ventilation system is suitable for peacetime and wartime combined medical public buildings or respiratory tract infectious disease areas, and is low in energy consumption.

Description

Technical Field

[0001] The invention relates to the field of air conditioning and ventilation engineering, and in particular to a multi-mode energy-saving central air conditioning and ventilation system suitable for medical and health public buildings or respiratory infectious disease areas used in both peacetime and wartime applications. Background Art

[0002] At present, most medical and health public buildings use centralized air conditioning and ventilation systems to regulate indoor air temperature. Some use full return air operation for energy saving, while others use full fresh air operation to meet indoor fresh air demand. Although the former is energy-saving, it cannot guarantee the necessary indoor fresh air demand. Although the latter guarantees the indoor fresh air demand, the energy consumption is relatively higher. Therefore, in recent years, in order to meet the indoor fresh air demand and energy saving and consumption reduction requirements, many hospitals have chosen to use fresh air units with sensible heat / full heat recovery when designing and building general diagnosis areas and wards. However, most of the current fresh air units with sensible heat / full heat recovery cannot achieve return air operation. Although such fresh air units are equipped with heat recovery devices in the new exhaust air room, they still consume more energy than directly using return air operation.

[0003] At the same time, due to the manufacturing process, the heat recovery device in the fresh air room often has a certain amount of air leakage. The academic community clearly pointed out that if there is fresh air, the return air should be closed and the fresh air should be used. If there is no fresh air, the operation should be stopped and the windows should be opened for ventilation. This will inevitably lead to two situations. One is the increase in energy consumption caused by the operation of fresh air after closing the return air, and the other is that after the air conditioner is stopped without fresh air, it is difficult to ventilate the inner room without windows, and it is also difficult to meet the indoor air temperature regulation requirements.

[0004] In addition, the current fresh air units and air-conditioning units are mostly set up separately, and the system structure integration is not high; the cleanliness of the air-conditioning units is poor during return air operation, and the exhaust air is mostly not filtered, resulting in dust accumulation in the heat exchanger of the heat recovery unit, affecting the heat exchange efficiency. Summary of the invention

[0005] In view of this, the present invention proposes a multi-mode energy-saving central air-conditioning and ventilation system.

[0006] The objective of the present invention is achieved through the following technical solutions: a multi-mode energy-saving central air conditioning ventilation system, including a fresh air system and an exhaust system, wherein the fresh air system includes a fresh air inlet duct, a fresh air primary filter box, a fresh air medium efficiency 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 air primary filter box, an exhaust air medium efficiency filter box, an exhaust air return box, an exhaust air collecting box and an exhaust air outlet duct connected in sequence along the wind direction, and an exhaust air sterilization and purification mechanism connected front and back is also provided between the exhaust air primary filter box and the exhaust air medium efficiency filter box, and a return air circulation valve is provided in the exhaust air return box, and the return air circulation valve is connected to the fresh air medium efficiency filter box. Among them, the return air circulation valve and the exhaust air sterilization and purification mechanism can be opened at the same time, closed at the same time, only the return air circulation valve is opened, or only the exhaust air sterilization and purification mechanism is opened.

[0007] The central air conditioning and ventilation system set up in the above manner has multiple working modes; 1. Full supply and full exhaust working mode under non-special circumstances: the exhaust air sterilization and purification mechanism and the return air circulation valve are closed at the same time, and the exhaust return air is directly discharged to the outside. That is, the fresh air system and the exhaust 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, so that the exhaust return air is filtered and sterilized and purified twice before being discharged to the outside, which is suitable for use in respiratory infectious wards or when public health events occur. 3. Full return air mode under non-special circumstances: the return air circulation valve is opened, the fresh air inlet is closed, 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 sent back into the room as fresh air. 4. 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 intake is closed, so that the exhaust return air is sent to the fresh air medium efficiency filter box through the return air circulation valve after two filtrations and sterilization purifications, and is sent back into the room as fresh air. The central air conditioning and ventilation system of the present invention is particularly suitable for new buildings of public medical and health buildings or respiratory infectious wards that combine peacetime and wartime, and can operate safely and reliably in the event of respiratory infectious public health incidents. For example, when a public health incident occurs, not only can the full supply and full exhaust working mode under special circumstances be adopted for operation, but also the full return air mode under special circumstances for energy saving can be adopted. And the exhaust air that has been filtered, sterilized and purified twice can achieve low energy consumption and high safety for the operation of the central air conditioning system.

[0008] To further achieve energy saving, the central air conditioning ventilation system of the present invention also includes a fresh air exhaust heat exchanger, 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 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 collection box, and the two groups of inlet and outlet air ducts perform heat exchange in the fresh air exhaust heat exchanger. By exchanging heat between exhaust air and fresh air in the heat exchanger, the burden of air conditioning operation can be reduced, and the effect of reducing energy consumption can be achieved. Moreover, the exhaust air is filtered, sterilized and purified twice, which ensures the heat conversion efficiency of the fresh air heat exchanger and reduces energy consumption.

[0009] Preferably, a fresh air inlet temperature sensor and a fresh air inlet valve are arranged in the fresh air inlet duct along the wind direction, and a fresh air supply temperature sensor is arranged in the fresh air supply duct.

[0010] Furthermore, 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 differential pressure sensor, and 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 differential pressure sensor, and the return air circulation valve is connected to the fresh air medium efficiency filter and the second wind resistance differential pressure sensor. The wind resistance differential pressure sensor can monitor the cleanliness of the fresh air primary filter and the fresh air medium efficiency filter, and when the wind resistance differential pressure sensor exceeds the pressure difference setting threshold, an alarm is issued in the control system to remind the staff to clean or replace it.

[0011] Furthermore, an air conditioning heat exchange mechanism is also provided in the fresh air medium efficiency filter box, and the air conditioning heat exchange mechanism is located after the exhaust air circulation air valve. A fresh air fan is also provided at the air outlet of the fresh air medium efficiency filter box.

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

[0013] Furthermore, the exhaust sterilization and purification mechanism includes an ultraviolet lamp sterilization bellows and an electrostatic air purification bellows connected in the downwind direction, and ultraviolet lamps are respectively provided on the opposite side walls in the downwind direction of the ultraviolet lamp sterilization bellows, and a lampshade is provided outside the ultraviolet lamp. A cover plate is provided on the side wall on which the ultraviolet lamp is installed, and the cover plate covers the ultraviolet lamp and is detachably connected to the side wall. The inner wall on the air inlet side and the inner wall on the air outlet side of the ultraviolet lamp sterilization bellows are respectively provided with spoiler wind shields, and the two spoiler wind shields are arranged in parallel and staggered manner, wherein the spoiler baffle A located on the inner wall on the air inlet side has an acute angle with the air inlet of the ultraviolet lamp sterilization bellows, and the spoiler baffle B located on the inner wall on the air outlet side has an acute angle with the air outlet of the ultraviolet lamp sterilization bellows; an electrostatic air purification device is installed in the electrostatic air purification bellows. The spoiler wind shield makes the return air in the ultraviolet lamp sterilization bellows more turbulent, and the airflow stays longer in the ultraviolet lamp sterilization bellows, so the sterilization effect is more ideal. And the return air after ultraviolet lamp sterilization and electrostatic air purification is filtered again with medium efficiency, so the filtering effect is better. In addition, warning lights such as ultraviolet sterilization and ultraviolet sterilization lamp failure can be set outside the ultraviolet sterilization bellows to remind maintenance personnel not to open the ultraviolet lamp cover for maintenance during ultraviolet sterilization, and to repair the ultraviolet lamp in time after failure. The ultraviolet sterilization lamp is externally mounted and can be opened from the external cover for disassembly, maintenance and replacement, making later maintenance more convenient.

[0014] In order to further save energy consumption, the exhaust primary filter box is integrated with the exhaust air inlet duct, and an exhaust temperature sensor and an exhaust primary filter are arranged in the exhaust air inlet duct along the wind direction, and the exhaust primary filter is connected to the third wind resistance pressure difference sensor at both ends; the exhaust medium efficiency filter box is provided with an exhaust medium efficiency filter, and the exhaust medium efficiency filter is connected to the fourth wind resistance pressure difference sensor at both ends. In the present invention, the exhaust air is filtered twice, which can filter out most of the impurities in the exhaust air, thereby improving the heat exchange efficiency of the new exhaust heat exchanger and reducing energy consumption. At the same time, the exhaust air that has been filtered twice can be safely discharged to the outdoors for medical buildings that are not in special circumstances, even if a small amount of leakage occurs in the new exhaust heat exchanger. And through the setting of the third and fourth wind resistance pressure difference sensors, when the exhaust primary filter and the exhaust medium efficiency filter are blocked, the staff can be reminded to clean or replace them in time, thereby reducing the blockage failure rate of the new exhaust heat exchanger.

[0015] Preferably, 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.

[0016] In order to further reduce noise and dynamic pressure loss, the inner walls of the fresh air primary filter box, exhaust air return box and exhaust air collecting box are provided with sound-absorbing materials / structures, and static pressure boxes are provided at the front ends of the fresh air inlet duct and the exhaust air inlet duct.

[0017] Due to the adoption of the above technical solution, the present invention has the following advantages: The central air conditioning and ventilation system of the present invention has multiple working modes and is suitable for multiple working scenes. The present invention sets an exhaust sterilization and purification mechanism between the primary filter box and the medium efficiency filter box of the exhaust system, sets an exhaust return air box after the exhaust medium efficiency filter box, and sets a return air circulation valve connected to the fresh air medium efficiency filter box in the exhaust return air box. In this way, a central air conditioning and ventilation system with multiple working modes can be provided for public health buildings, including a full-supply and full-exhaust working mode and a full-return air working mode applicable to non-special circumstances, and a full-supply and full-exhaust working mode, a full-return air working mode, and a partial return air + fresh air working mode after sterilization when applied to respiratory infectious wards or respiratory infectious public health events. In addition, the central air conditioning and ventilation system of the present invention can also open a fresh air independent operation mode, a fresh air air conditioning operation mode, a full exhaust independent operation mode, a full exhaust sterilization and purification mode, a full-supply and full-exhaust air conditioning operation mode, a partial return air + fresh air working mode, etc., with a high degree of integration.

[0018] The central air conditioning ventilation system of the present invention has low energy consumption and high thermal efficiency. First, the present invention utilizes a new return air heat exchanger to allow exhaust air and fresh air to perform heat exchange in a full-supply and full-exhaust working mode, which can reduce the air conditioning heat exchange load demand of the air conditioning heat exchange coil and reduce energy consumption. Second, the present invention provides an exhaust air primary filter box and an exhaust air medium efficiency filter box for the exhaust system, and also embeds an exhaust air sterilization and purification mechanism between the exhaust air primary filter box and the exhaust air medium efficiency filter box, which can not only reduce the dust accumulation speed 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 blockage speed of the exhaust air medium efficiency filter, and the return air after two filtrations, sterilizations and purifications has a high cleanliness, which avoids the dust accumulation and dirt blockage of the new exhaust air heat exchanger due to the long-term operation of the exhaust air 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 that has been filtered, sterilized and purified twice has a high cleanliness degree, which can avoid the rapid dirtiness and blockage of the air-conditioning heat exchange coil in the full return air operation mode, improve the heat exchange efficiency and achieve energy-saving effect.

[0019] 4. The special setting of the exhaust system of the present invention, namely, primary filtration, sterilization, purification, and medium filtration are carried out in sequence, and a special ultraviolet lamp sterilization structure is adopted, which can achieve very good sterilization and purification effects. It is especially suitable for buildings in areas with respiratory infectious diseases, which can avoid the spread of viruses caused by the operation of air conditioners, and is suitable for medical institutions that combine peacetime and wartime, with low infection risks.

[0020] 5. In the present invention, 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 which only have 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. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The accompanying drawings of the present invention are as follows.

[0022] Figure 1 This is a simplified structural diagram of the central air conditioning and ventilation system in Example 1; Figure 2 This is a simplified structural diagram of the central air conditioning and ventilation system in Example 2.

[0023] Explanation of reference numerals: fresh air inlet duct 1, fresh air primary filter box 2, fresh air medium 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 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 water 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

[0024] Embodiments of the present application are described in detail below, and 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 with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be construed as limiting the present application. On the contrary, the embodiments of the present application include all changes, modifications and equivalents that fall within the spirit and connotation of the appended claims.

[0025] Example 1: Figure 1 As shown, this embodiment provides a central air conditioning and ventilation system, including a fresh air system and an exhaust air system.

[0026] The fresh air system comprises 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. Among them, a fresh air inlet temperature sensor 5 and a fresh air inlet air valve 6 are arranged in sequence along the wind direction in the fresh air inlet duct 1. 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, and the fresh air fan discharges the fresh air 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 water accumulation pan 14 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 15 passing through the heat exchange fins, the water inlet pipe 16 of the air conditioning water circulation pipe is located outside the box and is provided with a water inlet valve 17, a Y-type filter 18 and a proportional flow regulating valve 19 in sequence along the water flow direction, the water outlet pipe 20 of the air conditioning water circulation pipe is located outside the box and is provided with an air conditioning water temperature sensor 21 and a water outlet valve 22 in sequence along the water flow direction; the condensate water accumulation pan is connected to a condensate water outlet pipe 23, and a condensate water valve 24 is provided on the condensate water outlet pipe. A fresh air supply temperature sensor 25 is provided in the fresh air supply duct.

[0027] The exhaust system includes an exhaust air inlet duct 26, an exhaust air primary filter box, an exhaust air medium filter box 27, an exhaust air return 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 air primary filter box can be two mechanisms, or they can be integrated into one. In this embodiment, the exhaust air primary filter box is integrated in the exhaust air inlet duct, and the exhaust air inlet duct is provided with an exhaust air temperature sensor 31 and an exhaust air primary filter 32 in the windward box, and a third wind resistance pressure difference sensor 33 is connected at both ends of the exhaust air primary filter. An exhaust air medium efficiency filter 34 is provided in the exhaust air medium efficiency filter box, and a fourth wind resistance pressure difference sensor 35 is connected at both ends of the exhaust air medium efficiency filter. An exhaust fan 36 is provided at the air outlet of the exhaust medium efficiency filter box, and the exhaust fan discharges the return air after the secondary 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, and 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 secondary 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.

[0028] 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, and the two groups of inlet and outlet air ducts perform heat exchange in the fresh air exhaust heat exchanger.

[0029] As another implementation in this embodiment, the inner walls of the fresh air primary filter box, the exhaust air return box and the 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.

[0030] In the central air conditioning ventilation system of the present embodiment, the fresh air fan is linked with the fresh air inlet valve. When the control system remotely starts the fresh air fan, the fresh air inlet valve will be automatically opened first, and then the fresh air fan will start to run. Otherwise, the fresh air fan will be closed first and then the fresh air inlet valve will be closed. When the fresh air system is turned on, the outdoor fresh air enters through the fresh air inlet duct, enters the fresh air primary filter air box after passing through the fresh air inlet valve, and enters the fresh exhaust air heat exchanger for heat exchange with the exhaust air after being filtered by the primary filter. After the fresh air heat exchanger and the exhaust air are heat exchanged, the fresh air enters the fresh air medium efficiency filter box, and is filtered twice 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 sent into the room by the fresh air fan through the fresh air duct. In addition, the proportional flow control valve in the present embodiment is linked with the exhaust air temperature sensor, and the opening of the proportional flow control valve is adjusted according to the exhaust air temperature, thereby regulating the temperature of the fresh air sent into the room.

[0031] When the fresh air primary filter is clogged, the pressure difference between the front and rear of the fresh air primary filter will increase. When the first wind resistance pressure difference sensor detects that the pressure difference exceeds the set threshold, an alarm will be issued in the control system, thereby reminding the staff to clean or replace the fresh air primary filter in time. When the fresh air medium efficiency filter is clogged, the second wind resistance pressure difference sensor detects that the pressure difference exceeds the set threshold, and an alarm will be issued in the control system, thereby reminding the staff to replace the fresh air medium efficiency filter in time.

[0032] The exhaust fan is linked with the exhaust air valve. When the control system remotely starts the exhaust fan, the exhaust air valve will be automatically opened first, and then the exhaust fan will start to run. Otherwise, the exhaust fan will be closed first and then the exhaust air valve. When the exhaust system is turned on, the indoor return air enters through the exhaust air inlet duct and is filtered for the first time through the exhaust primary filter, and then enters the exhaust medium efficiency filter box for secondary filtration through the exhaust medium efficiency filter. After the exhaust air has been filtered twice, it is discharged outdoors through the exhaust air outlet duct after heat exchange with the fresh air through the new exhaust heat exchanger.

[0033] When the exhaust air primary filter is clogged, the wind pressure difference before and after the exhaust air primary filter will increase. When the third wind resistance pressure difference sensor detects that the pressure difference exceeds the set threshold, an alarm is triggered in the control system, thereby reminding the staff to replace the exhaust air primary filter in time. When the exhaust air intermediate filter is clogged, the fourth wind resistance pressure difference sensor detects that the pressure difference exceeds the set threshold, and an alarm is triggered in the control system, thereby reminding the staff to clean or replace the exhaust air intermediate filter in time.

[0034] 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.

[0035] In this embodiment, the return air heat exchanger is used to exchange heat between the return air and the fresh air, which can reduce the air conditioning heat exchange load demand of the air conditioning heat exchange coil and reduce energy consumption. And when the return air that has been filtered twice passes through the heat exchanger, it can avoid the dust accumulation and blockage of the new exhaust air heat exchanger caused by long-term exhaust operation, thereby ensuring the heat exchange efficiency of the new exhaust air heat exchanger. In addition, in this embodiment, the pressure difference before and after the filter is monitored by four wind resistance pressure difference sensors, and the filter that is blocked can be cleaned or replaced in time, which improves the heat exchange efficiency in disguise.

[0036] Moreover, the exhaust system in this embodiment also has built-in exhaust return air box and return air circulation valve, which can enable the central air conditioning ventilation system in this embodiment to realize multiple working modes, such as separate fresh air working mode, fresh air air conditioning working mode, separate exhaust mode, full supply and full exhaust mode of fresh air exhaust, partial return air + fresh air mode with return air circulation valve opened, full return air mode with return air circulation valve opened, etc. Moreover, in the partial return air or full return air mode, the exhaust air is filtered twice, with high cleanliness, which can ensure the quality of return air, reduce the operating heat load demand of the air conditioning heat exchange mechanism, and reduce energy consumption.

[0037] In addition, in the present 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 which only have heat recovery or return air operation, the modification can be easily realized so that the existing air-conditioning system can also realize the energy-saving air-conditioning system in the present embodiment.

[0038] As an option, the air conditioning heat exchange mechanism in this implementation diagram is a 2-pipe air conditioning water system. For areas with constant temperature and humidity or higher air conditioning requirements, a 4-pipe air conditioning water system can be used.

[0039] Example 2: Figure 2 As shown, this embodiment provides a central air conditioning and ventilation system, including a fresh air system and an exhaust air system.

[0040] The fresh air system comprises 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. Among them, a fresh air inlet temperature sensor 5 and a fresh air inlet air valve 6 are arranged in sequence along the wind direction in the fresh air inlet duct. 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, and the fresh air fan discharges the fresh air 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 water accumulation pan 14 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 15 passing through the heat exchange fins, the water inlet pipe 16 of the air conditioning water circulation pipe is located outside the box and is provided with a water inlet valve 17, a Y-type filter 18 and a proportional flow regulating valve 19 in sequence along the water flow direction, the water outlet pipe 20 of the air conditioning water circulation pipe is located outside the box and is provided with an air conditioning water temperature sensor 21 and a water outlet valve 22 in sequence along the water flow direction; the condensate water accumulation pan is connected to a condensate water outlet pipe 23, and a condensate water valve 24 is provided on the condensate water outlet pipe. A fresh air supply temperature sensor 25 is provided in the fresh air supply duct.

[0041] The exhaust system includes an exhaust air inlet duct 26, an exhaust air primary filter box, an exhaust air sterilization and purification mechanism, an exhaust air medium filter box 27, an exhaust air return box 28, an exhaust air collection box 29 and an exhaust air outlet duct 30, which are connected in sequence along the wind direction. Among them, the exhaust air inlet duct and the exhaust air primary filter box can be two mechanisms, or they can be integrated into one. In this embodiment, the exhaust air primary filter box is integrated in the exhaust air inlet duct, and the exhaust air inlet duct is provided with an exhaust air temperature sensor 31 and an exhaust air primary filter 32 in the windward box, and a third wind resistance pressure difference sensor 33 is connected at both ends of the exhaust air primary filter. An exhaust air medium filter 34 is provided in the exhaust air medium filter box, and a fourth wind resistance pressure difference sensor 35 is connected at both ends of the exhaust air medium filter. An exhaust fan 36 is provided at the air outlet of the exhaust air medium filter box, and the exhaust fan discharges the return air filtered in the exhaust air medium filter box into the exhaust air return box. The exhaust air return box is provided with an exhaust air circulation 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. An exhaust air valve 38 is provided in the exhaust air outlet duct.

[0042] 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, and the two groups of inlet and outlet air ducts perform heat exchange in the fresh air exhaust heat exchanger.

[0043] 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 ultraviolet lamps 42, and a lampshade 43 is provided outside the ultraviolet lamp. A cover plate 44 is provided on the side wall where the ultraviolet lamp is installed, and 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 later repairs and maintenance more convenient.

[0044] 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 spoiler wind shields 46, and the two spoiler wind shields are arranged in parallel and staggered, wherein the spoiler baffle A located on the inner wall of the air inlet side and the air inlet of the ultraviolet lamp sterilization bellows are at an acute angle, and the spoiler baffle B located on the inner wall of the air outlet side and the air outlet of the ultraviolet lamp sterilization bellows are at an acute angle. The spoiler wind shield makes the return air in the ultraviolet lamp sterilization bellows more turbulent, the airflow stays longer in the ultraviolet lamp sterilization bellows, 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 repeated here. The return air after ultraviolet lamp sterilization and electrostatic air purification is filtered again with medium efficiency, and the filtering effect is better.

[0045] As another implementation of this embodiment, the inner walls of the fresh air primary filter box, the exhaust air return box and the 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.

[0046] The central air conditioning and ventilation system of this embodiment has multiple working modes and is suitable for multiple working scenarios. In this embodiment, an exhaust air sterilization and purification mechanism is arranged between the primary filter box and the medium efficiency filter box of the exhaust system, an exhaust air return box is arranged after the exhaust medium efficiency filter box, and a return air circulation valve connected to the fresh air medium efficiency filter box is arranged in the exhaust air return box. By opening and closing the return air circulation valve and the exhaust air 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 air 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 air 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 twice and purified and 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 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 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 partially utilize the return air, which is more energy-saving 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 the exhaust air valve are fully opened. At this time, part of the return air will enter the fresh air medium efficiency filter box to 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 operation, which is more energy-saving than full delivery 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 sent to the fresh air medium efficiency filter box through the return air circulation valve after two filtrations, and is sent back 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 the 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 before being 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 can also reduce the heat load demand of the air conditioning heat exchange mechanism, reduce energy consumption, and the return air is filtered and sterilized twice, which is very clean and suitable for use in respiratory infectious wards or public health events, and there is no need to worry about the infection problem caused by exhausting to the outdoors. In addition, the fresh air system or the exhaust system can be started separately, and different operation modes can be matched according to the temperature in the building, such as closing the air conditioning heat exchange mechanism, opening the heating function of the air conditioning heat exchange mechanism, and opening the cooling function of the air conditioning heat exchange mechanism.

[0047] 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 for respiratory infectious wards, and can operate safely and reliably when a respiratory infectious public health incident occurs. For example, when a public health incident occurs, not only can the full supply and full exhaust working mode under special circumstances be adopted for operation, but also the full return air mode under special circumstances can be adopted for energy-saving operation. And the central air conditioning system can achieve low energy consumption and high safety.

[0048] Moreover, the central air conditioning ventilation system of the present embodiment has low energy consumption and high thermal efficiency. First, in the present embodiment, the new 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 medium efficiency filter bellows, which can not only reduce the dust accumulation speed of the return air dust in the electrostatic purification device, reduce the cleaning and maintenance of the electrostatic purification device, but also slow down the dirty clogging speed of the exhaust air medium efficiency filter, and the return air cleanliness after two filtrations, sterilizations and purifications is high, which avoids the dust accumulation and dirty clogging of the new exhaust air heat exchanger caused by the long-term operation of the exhaust air 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 cleanliness after two filtrations, sterilizations and purifications is high, and the sterilization effect is good, which can avoid the rapid dirty 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.

[0049] 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 in the present invention.

[0050] 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 preferred embodiments, those skilled in the art should understand that various changes may be made to it in form and details without departing from the scope defined by the claims of the present invention.

Claims

1. A multi-mode energy-saving central air conditioning 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 return air box, an exhaust air collecting box and an exhaust air outlet duct that are connected in sequence along the wind direction. An exhaust sterilization and purification mechanism that is connected front to back is also provided between the exhaust primary filter box and the exhaust medium filter box. 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 filter box.

2. The multi-mode energy-saving central air conditioning and ventilation system according to claim 1, characterized in that: It also includes a fresh air exhaust heat exchanger, which 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.

3. The multi-mode energy-saving central air conditioning and ventilation system according to claim 2, 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, and a fresh air supply temperature sensor is arranged in the fresh air supply duct.

4. The multi-mode energy-saving central air conditioning and ventilation system according to claim 3, characterized in that: A fresh air primary filter is arranged in the fresh air primary filter box, and the two ends of the fresh air primary filter are connected to the first wind resistance pressure difference sensor. A fresh air medium efficiency filter is arranged in the fresh air medium efficiency filter box, and the two ends of the fresh air medium efficiency filter are connected to the second wind resistance pressure difference sensor. The exhaust air circulation air valve is connected after the fresh air medium efficiency filter and the second wind resistance pressure difference sensor.

5. The multi-mode central air conditioning and ventilation system according to claim 4, characterized in that: The fresh air medium efficiency filter box is also provided with an air conditioning heat exchange mechanism, and the air conditioning heat exchange mechanism is located after the return air circulation valve. A fresh air fan is also provided at the air outlet of the fresh air medium efficiency filter box, and the fresh air fan is linked with the fresh air inlet valve.

6. The multi-mode energy-saving central air conditioning and ventilation system according to claim 5, 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 box and is provided with an inlet valve, a Y-type filter and a proportional flow regulating valve in sequence along the water flow direction, the water outlet pipe of the air-conditioning water circulation pipe is located outside the box and is provided with an air-conditioning water temperature sensor and an outlet valve in sequence along the water flow direction, 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.

7. The multi-mode energy-saving central air conditioning and ventilation system according to claim 2, 3, 4, 5 or 6, characterized in that: The exhaust sterilization and purification mechanism comprises an ultraviolet lamp sterilization bellows and an electrostatic air purification bellows connected in the downwind direction; ultraviolet lamps are respectively arranged on the opposite side walls in the downwind direction of the ultraviolet lamp sterilization bellows, a lampshade is arranged outside the ultraviolet lamp, a cover plate is arranged on the side wall on which the ultraviolet lamp is installed, the cover plate covers the ultraviolet lamp and is detachably connected to the side wall, spoiler wind shields are respectively arranged on the inner wall on the air inlet side and the inner wall on the air outlet side of the ultraviolet lamp sterilization bellows, and the two spoiler wind shields are arranged in parallel and staggered manner, wherein the spoiler baffle A located on the inner wall on the air inlet side forms an acute angle with the air inlet of the ultraviolet lamp sterilization bellows, and the spoiler baffle B located on the inner wall on the air outlet side forms an acute angle with the air outlet of the ultraviolet lamp sterilization bellows; an electrostatic air purification device is installed in the electrostatic air purification bellows.

8. The multi-mode energy-saving central air conditioning and ventilation system according to claim 7, characterized in that: The exhaust primary filter box is integrated with the exhaust air inlet duct, and an exhaust temperature sensor and an exhaust primary filter are arranged along the wind direction in the exhaust air inlet duct, 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.

9. The multi-mode energy-saving central air conditioning and ventilation system according to claim 8, characterized in that: An exhaust fan is arranged at the air outlet in the exhaust medium-efficiency filter box, an exhaust air valve is arranged in the exhaust air outlet duct, and the exhaust fan is linked with the exhaust air valve.

10. The multi-mode energy-saving central air conditioning and ventilation system according to claim 9, characterized in that: The inner walls of the fresh air primary filter box, the exhaust air return box and the exhaust air collecting box are provided with sound absorbing materials, and 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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