Fresh air exhaust control system and intelligent control method for rest room of residential building

Abstract

The invention discloses a residential building toilet fresh air exhaust control system and an intelligent control method. The method comprises the steps that data of a door state sensor, a closestool state sensor, a hydrogen sulfide sensor and a biological aerosol sensor are collected; the data is transmitted to the intelligent gateway through a communication link; performing multi-source data fusion analysis by the intelligent gateway, and identifying a toilet flushing event, a water seal damage risk and a pollutant concentration trend; according to event recognition and trend prediction results, an exhaust fan and a fresh air fan are controlled to operate in advance, and rapid discharge of pollutants and indoor positive pressure maintenance are achieved; and when the water seal damage risk is detected, positive pressure air supply, pollution gas discharge and water replenishing prompts are triggered. Prediction and intervention control can be carried out before pollutant aerosol is generated, and the ventilation efficiency and the prevention and control effect are remarkably improved.

Description

Technical Field

[0001] This invention belongs to the field of intelligent control of building environment and pollution transmission blocking technology, and relates to an intelligent system and method for controlling fresh air and exhaust in the bathroom of a residential building, particularly to a technology for coordinated operation of fresh air and exhaust based on usage status recognition and pollutant / aerosol prediction. Background Technology

[0002] Building drainage systems are potential channels for the spread of gaseous pollutants and pathogens. Once the water seal in a bathroom floor drain fails, an airway will be created between indoor air and the drainage system, significantly increasing the risk of pollutants entering the room. According to relevant Chinese regulations, the water seal depth of a floor drain should not be less than 50 mm. However, under the influence of factors such as low-frequency use, evaporation, transient negative pressure, and changes in ventilation conditions, the water seal is prone to damage or a reduction in its effective depth, significantly increasing the risk of aerosol pollutants from the drainage system entering the room.

[0003] The use of the bathroom itself generates a large amount of aerosols; existing research has shown that flushing a toilet can produce more than 290,000 aerosol particles. Turning on the exhaust fan alone can create negative pressure, which helps to remove aerosols generated by users, but if the water seal is broken, it can draw contaminants from the drainage system into the room. Turning on the fresh air fan alone can create positive pressure, preventing contaminants from the drainage system from entering the room, but it may push aerosols generated by users into adjacent public areas. Current technology struggles to simultaneously address both types of risks in different scenarios and lacks predictive and refined control methods based on usage status. Summary of the Invention

[0004] In order to overcome the above-mentioned defects of the prior art, the present invention provides a fresh air and exhaust ventilation control system and intelligent control method for bathrooms in residential buildings, so as to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a monitoring and control system for pollutants and aerosols in residential building bathrooms, comprising: Door status sensor: Installed on the outside of the bathroom door frame to detect people entering and exiting and the opening status of doors and windows; Toilet usage status sensors: including toilet posture sensors and toilet flushing sensors, used to identify the type of toilet use (urination, defecation, flushing) and the time of flushing action, and to predict key time points for aerosol generation. Hydrogen sulfide sensor: Used to monitor volatile gaseous pollutants released from drainage systems at floor drains; Bioaerosol sensor: used to detect the quantity of aerosols of different particle sizes and the concentration of active bioaerosols in the air; Fresh air ventilator: Used to replenish clean, fresh air into the room and maintain a slight positive pressure to prevent backflow of pollutants from drainage pipes; the ventilator should support dynamic adjustment of airflow based on indoor pressure and pollutant concentration; Exhaust fan: Installed in the bathroom ceiling near the toilet, with the air outlet connected to the building's exhaust shaft and a check valve installed at the air outlet to prevent pollutants from flowing back into the exhaust shaft; the fan can also precisely adjust its exhaust capacity according to the aerosol concentration to maintain ventilation. Intelligent gateway: integrates functions such as data acquisition, status recognition, pollutant prediction, and control logic execution. The various sensors are connected to the intelligent gateway via wired or wireless means. The intelligent gateway dynamically controls the operation status of the fresh air fan and exhaust fan based on real-time data and prediction models.

[0006] A method for predicting pollutants and intelligently controlling fresh air and exhaust in bathrooms of residential buildings includes: Step A: Loading the pollutant prediction and identification model. The smart gateway has a pre-configured toilet event identification model, pollutant prediction model, and airflow calculation model, which are loaded during system initialization. This includes: Toilet event recognition model: Combining signals collected by toilet status sensors, it identifies the types of bathroom usage events, including urination, defecation, flushing, etc., and outputs the corresponding pollutant generation categories and initial parameters of the prediction curve. Aerosol release prediction model: Based on the characteristics of toilet models and combined with historical pollutant generation curves matched with event types, the model predicts the release peak, rise time, decay rate and total release amount. Air volume coordinated control model: Based on the bathroom space volume, fresh air unit and exhaust fan efficiency and other conditions, calculate the operating frequency and operating time of the fresh air unit and exhaust fan required to reach the set air quality safety threshold.

[0007] Step B: Pollutant Emission Control. When the door status sensor detects someone entering the restroom, the fresh air fan is activated first to provide fresh air and establish positive pressure indoors; simultaneously, the smart gateway pre-loads corresponding event prediction parameters. When the smart gateway identifies: Urinating incident: Based on the incident identification results, the exhaust fan operates at low power, while the fresh air fan remains running to meet basic ventilation and gas dilution requirements; Fecal matter incident: The exhaust fan operates at high power, and the fresh air fan operates simultaneously to ensure that pollutants are stably and effectively discharged during use; Flushing incidents: Based on the prediction model, the amount of aerosols generated by flushing is estimated, and the exhaust and fresh air power is dynamically adjusted accordingly to form a stable negative pressure to quickly remove pollutants while preventing them from overflowing into public spaces.

[0008] Step C: Feedback on Operating Conditions. When personnel are detected leaving the restroom, the fresh air fan is shut off, while the exhaust fan is increased to its maximum power to accelerate pollutant emissions. Based on the predicted aerosol generation and fan parameters, the estimated time required for complete pollutant removal is calculated; after the estimated tail-end emissions are completed, monitoring is conducted using a bioaerosol sensor. When the aerosol concentration rises rapidly after flushing, gradually decreases during the tail discharge, and stabilizes at the end, the exhaust fan is turned off and the system enters standby mode. If the aerosol concentration remains high or even rises at the expected end time, and the hydrogen sulfide concentration continues to exceed the standard, it is determined that the water seal may have failed. The fresh air fan will be started to maintain positive pressure, and a water seal failure warning will be issued.

[0009] Step D: Standby Mode. If step C does not trigger the water seal failure warning, and the door status sensor continues to detect that the bathroom is unused, the system enters standby mode. The bioaerosol sensor is stopped, and only the hydrogen sulfide sensor continues to sample at low frequency. If the hydrogen sulfide concentration continues to exceed the threshold and shows an upward trend, a high risk is confirmed, and a water seal failure warning is immediately issued. At the same time, the fresh air fan and exhaust fan are started to maintain stable discharge of polluted air under positive pressure conditions under the coordination of the smart gateway. The bioaerosol sensor is turned on simultaneously. If the detected bioaerosol value also exceeds the safety threshold, the water seal failure is further confirmed. The system continues to run until the values ​​of both types of sensors return to the safety threshold. Then, the fresh air and exhaust fans stop operating, the bioaerosol sensor stops again, and the system returns to low-power standby mode.

[0010] Step E: Special Operating Conditions. When prolonged lingering of personnel is detected, and aerosol concentration fluctuates abnormally, but the toilet status sensor does not record any usage events, and the hydrogen sulfide concentration is normal, it is determined to be a low-risk aerosol scenario such as showering or handwashing. The system maintains low-power operation of the fresh air fan and exhaust fan, which can exhaust humid air without significantly disrupting the thermal and humidity environment of the bathroom, thereby improving comfort while ensuring air quality.

[0011] The technical effects and advantages of this invention are as follows: 1. This invention improves the accuracy of event identification and pollutant prediction through multi-sensor data fusion, and predicts the pollutant generation patterns based on different toilet events, thereby achieving active adaptation of fan parameters and pollutant aerosol concentration. 2. By using a smart gateway to coordinate the operation of fresh air fans and exhaust fans, the efficiency of pollutant aerosol discharge is improved while maintaining the supply of fresh air to personnel, effectively avoiding the risk of spreading to public spaces; 3. Based on hydrogen sulfide trends, historical aerosol data, and predicted concentrations at specific time points, this system takes into account both indoor pollutant aerosol emissions and drainage pipe pollutant aerosol intrusion, thereby improving the accuracy and timeliness of water seal damage identification. 4. After the seal is broken, maintain a relatively positive pressure indoors through the fresh air fan to block aerosols in the drainage pipes from entering the room, and work with the exhaust fan to promptly remove pollutants that have entered the room; at the same time, issue a water replenishment reminder or warning to reduce the risk of pollution spread. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the toilet pollutant and aerosol monitoring system of the present invention; Figure 2 This is a flowchart of the method for predicting pollutants in the bathroom of a residential building and for intelligent control of fresh air and exhaust in accordance with the present invention.

[0013] The attached diagram is labeled as follows: 1. Drainage riser, 2. Drainage branch pipe, 3. Floor drain, 4. Toilet, 5. Exhaust fan, 6. Fresh air fan, 7. Smart gateway, 8. Door status sensor, 9. Toilet status sensor, 10. Hydrogen sulfide sensor, 11. Bioaerosol sensor, 12. Communication link. Detailed Implementation

[0014] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The described embodiments are only some embodiments of the present invention, and not all embodiments.

[0015] A fresh air and exhaust ventilation control system and intelligent control method for bathrooms in residential buildings, such as Figure 1 As shown, Drainage riser 1: Connects to drainage branch pipes 2 on each floor and is used to discharge sewage and gas.

[0016] Drainage branch pipe 2: connects drainage riser 1 to floor drain 3 or toilet 4, and forms a water seal structure to prevent gas in the drainage system from entering the room.

[0017] Floor drain 3: Installed on the bathroom floor, connected to the drainage branch pipe 2 via a water seal.

[0018] Toilet 4: Connected to drain branch pipe 2.

[0019] Exhaust fan 5: Installed in the bathroom exhaust duct, responsible for exhausting indoor air and pollutant aerosols. It supports frequency conversion adjustment and is equipped with a spring-loaded check valve at the air outlet to prevent backflow of pollutants in the exhaust shaft. It is installed in the bathroom ceiling near the toilet 4.

[0020] Fresh air fan 6: Connected to the fresh air duct, it replenishes clean air to the bathroom during exhaust operation, maintains positive pressure, supports frequency conversion adjustment, and is equipped with a filter at the air inlet to filter outdoor particulate matter. It is installed on the north exterior wall of the bathroom, with the air inlet facing the open outdoor area, and the air outlet is connected to the bathroom interior through a duct.

[0021] Smart Gateway 7: As the core of system control, it establishes data and control connections with various sensors and wind turbines, and executes data fusion, event recognition, pollutant prediction and equipment collaborative control logic.

[0022] Door status sensor 8: Installed on the bathroom door or door frame to monitor the opening and closing status of the door and the entry and exit of people.

[0023] Toilet status sensor 9: Used to detect the usage status of the toilet, including posture monitoring and flushing event detection.

[0024] Hydrogen sulfide sensor 10: Installed above the bathroom floor drain 3 to monitor the real-time trend of hydrogen sulfide concentration changes.

[0025] Bioaerosol sensor 11: A laser particle counter type bioaerosol sensor is selected, with the detection direction vertically downward and aligned with the flushing area of ​​toilet 4, to monitor the number and activity ratio of bioaerosol particles generated during toilet use and flushing.

[0026] Communication link 12: includes wireless or wired communication, used to transmit data and control commands between smart gateway 7, various sensors and wind turbines.

[0027] A method for predicting pollutants in building bathrooms and for intelligent control of fresh air and exhaust systems, such as Figure 2 As shown, When a resident opens the bathroom door, the door status sensor 8 detects the "door open" signal and uploads it to the smart gateway 7 via the communication link 12. The intelligent gateway 7 immediately issues a command to control the fresh air fan 6 to start operating at medium power via the communication link 12; For example, if the smart gateway 7 detects a "urination event" through the posture sensor of the toilet status sensor 9, it will turn on the exhaust fan 5 to run at low power. For example, if the smart gateway 7 detects a "defecation event" through the posture sensor of the toilet status sensor 9, it will turn on the exhaust fan 5 to run at medium power. Subsequently, the resident triggered the toilet 4 to flush, and the flushing sensor of the toilet status sensor 9 detected the flushing signal and uploaded it to the smart gateway 7 through the communication link 12. The smart gateway 7 calls the prediction model and determines that it has entered the "peak period of flushing aerosol". It immediately issues an instruction: the exhaust fan 5 is increased to medium-high power, the fresh air fan 6 is finely adjusted to medium-low frequency, and a slight negative pressure is formed indoors. The bioaerosol sensor 11 detects that the aerosol concentration is close to the predicted peak value. The data is uploaded to the smart gateway 7 through the communication link 12. The gateway maintains the current parameters of the wind turbine. After flushing, the bioaerosol sensor 11 detects that the concentration remains at a low value. The smart gateway 7 issues an instruction: the exhaust fan 5 maintains medium power, the fresh air fan 6 returns to medium power, and the indoor pressure returns to positive. When the door status sensor 8 detects that someone has left, the smart gateway 7 issues a command: the fresh air fan 6 stops operating, the exhaust fan 5 is upgraded to high power, and the pollutant discharge time is estimated. If the expected discharge time ends, the bioaerosol sensor 11 detects that the concentration has stabilized within the safe threshold, the hydrogen sulfide sensor 10 detects that the concentration is normal, and the smart gateway 7 issues a command: the exhaust fan 5 stops operating, and the system enters standby mode. If the concentration of bioaerosol sensor 11 rises above the threshold and the concentration of hydrogen sulfide sensor 10 also exceeds the threshold, the smart gateway 7 determines that the water seal has failed and immediately issues an instruction: the fresh air fan 6 starts at high power 60% frequency, the exhaust fan 5 maintains medium power, and at the same time pushes a "water seal failure" warning to the user's mobile APP through the communication link 12. After the system enters standby mode, the bioaerosol sensor 11 stops sampling, and only the hydrogen sulfide sensor 10 samples at a low frequency. If the concentration of the hydrogen sulfide sensor 10 exceeds the threshold for three consecutive samplings and shows an upward trend, the smart gateway 7 immediately restarts the bioaerosol sensor 11. If the detected concentration also exceeds the standard, the fresh air fan 6 and the exhaust fan 5 are started until the pollutant concentration reaches the standard and then standby is restored.

[0028] In this embodiment, the communication link 12 can adopt ZigBee, Wi-Fi, or wired industrial Ethernet to ensure real-time and reliable data transmission. The system software can implement hierarchical control strategies and local / cloud data storage, facilitating long-term operation recording and optimization algorithm training.

[0029] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention.

Claims

1. A fresh air and exhaust ventilation control system for a residential building bathroom, characterized in that, The system includes a water riser (1), a drainage branch pipe (2), a floor drain (3), a toilet (4), an exhaust fan (5), a fresh air fan (6), a smart gateway (7), a door status sensor (8), a toilet status sensor (9), a hydrogen sulfide sensor (10), a bioaerosol sensor (11), and a communication link (12); the method is implemented based on the system and includes steps such as model loading, pre-control startup, dynamic regulation, feedback optimization, standby monitoring, and special adaptation. The exhaust fan (5) is installed in the bathroom ceiling near the toilet (4), and the air outlet is equipped with a check valve. The air outlet is connected to the building exhaust shaft through a pipe. The fresh air fan (6) is installed at a preset height on the exterior wall of the bathroom, with a high-efficiency air filter component installed at the air inlet and the air outlet connected to the bathroom interior through a pipe; The intelligent gateway (7) integrates a core control chip and a wireless communication module, supports wired interfaces and general communication protocols, has a built-in pollutant prediction model, and is installed in the bathroom's weak current box. The door status sensor (8) is an infrared beam type, installed at a preset height on the outside of the bathroom door frame, and is used to detect the opening and closing status of the door; The toilet status sensor (9) includes a sitting posture detection sensor and a flushing detection sensor. The sitting posture detection sensor is located on the underside of the toilet seat (4), and the flushing detection sensor is located on the flushing valve linkage of the toilet (4). The hydrogen sulfide sensor (10) is an electrochemical type and is installed on the wall at a preset height above the floor drain (3), with the sensor probe facing the floor drain (3). The bioaerosol sensor (11) is a laser particle counting type, which integrates a bioactive particle identification module and is installed in a preset position on the ceiling directly above the toilet (4); The communication link (12) includes a wired communication link and a wireless communication link. The wired communication link connects each sensor to the smart gateway (7), and the wireless communication link connects the smart gateway (7) to the exhaust fan (5) and the fresh air fan (6). At the same time, it supports wireless communication between the smart gateway (7) and external terminals and the building central control platform.

2. The method includes the following steps: Step 1: Model loading and parameter preset. The smart gateway (7) loads the toilet event recognition, pollutant prediction and air volume calculation model, and presets the sensor threshold and fan operating parameters. Step 2: Personnel entry and pre-control start-up. The door status sensor (8) detects personnel entering, and the fresh air fan (6) is started first to establish indoor micro-positive pressure. The gateway pre-reads the predicted parameters. Step 3: Event adaptation and dynamic control. The gateway determines the event type based on the toilet status sensor (9) and adapts the power of the exhaust fan (5) and the fresh air fan (6): when urinating, the exhaust fan has low power and the fresh air maintains positive pressure; when defecating, the exhaust fan has medium power and the fresh air maintains basic positive pressure; when flushing, the exhaust fan is more efficient and the fresh air is slightly adjusted to form a brief negative pressure. Step 4: Personnel departure and feedback optimization. When personnel departure is detected, the fresh air system is shut down and the exhaust system is improved. The pollution status is judged by combining the data from the bioaerosol (11) and hydrogen sulfide (10) sensors: if the standard is met, the exhaust system is shut down and enters standby mode; if abnormal, the water seal is determined to be in failure, and the fresh air system is started to operate at high positive pressure and the exhaust system is started to operate efficiently and an early warning is issued. Step 5: Standby monitoring and abnormal response. During standby, the bioaerosol sensor (11) is shut down and the hydrogen sulfide sensor (10) operates at a low frequency. When the hydrogen sulfide is abnormal, the dual sensors and ventilation components are restarted. After the standard is met, standby is restored. Step 6: Special scenario adaptation, identify showering and handwashing conditions, control the dual fans to operate at low power, and fine-tune the exhaust power in conjunction with temperature and humidity.

3. The fresh air and exhaust ventilation control system for bathrooms in residential buildings according to claim 1, characterized in that, The smart gateway (7) presets sensor control parameters, including the detection delay time of the door status sensor (8), the event type judgment conditions of the toilet status sensor (9), the safety threshold and warning threshold of the hydrogen sulfide sensor (10), and the safety threshold and warning threshold of the bioaerosol sensor (11).

4. The fresh air and exhaust ventilation control system for bathrooms in residential buildings according to claim 1, characterized in that, The smart gateway (7) presets fan control parameters, including parameters corresponding to the low power, medium power and high power operation modes of the exhaust fan (5), parameters corresponding to the low power, medium power and high power operation modes of the fresh air fan (6), and indoor positive pressure control targets under different operation modes.

5. The fresh air and exhaust ventilation control system for bathrooms in residential buildings according to claim 1, characterized in that, The pollutant prediction model of the smart gateway (7) takes the toilet event type, flushing frequency and usage duration as input parameters and outputs the aerosol peak, duration and diffusion range within a preset time.

6. The fresh air and exhaust ventilation control system for bathrooms in residential buildings according to claim 1, characterized in that, The smart gateway (7) has a built-in water seal failure judgment logic. When the condition that "the value of the bioaerosol sensor (11) does not decrease but increases after the personnel leave, and the hydrogen sulfide sensor (10) continues to exceed the preset warning threshold for a period of time" is met, it is determined that the water seal has failed, triggers the warning, and starts the collaborative control mode of high power of the fresh air fan (6) and high power of the exhaust fan (5).

7. The fresh air and exhaust ventilation control system for residential building bathrooms according to claim 1, characterized in that, The system has a standby mode. When the bathroom is unoccupied and the door is closed for a preset time, the bioaerosol sensor (11) stops sampling, the hydrogen sulfide sensor (10) extends the sampling interval, and both the exhaust fan (5) and the fresh air fan (6) stop running.

8. The fresh air and exhaust ventilation control system for bathrooms in residential buildings according to claim 1, characterized in that, Both the exhaust fan (5) and the fresh air fan (6) support pulse width modulation speed regulation and set start and stop delay time to avoid frequent start and stop; the air inlet of the fresh air fan (6) is equipped with a rainproof component, and the check valve at the air outlet of the exhaust fan (5) can prevent pollutants from flowing back into the exhaust shaft.

9. The fresh air and exhaust ventilation control system for bathrooms in residential buildings according to claim 1, characterized in that, The intelligent gateway (7) supports remote data interaction and control. It can display sensor data, fan operating status and early warning information in real time through external terminals, and also supports manually issuing fan start / stop and power adjustment commands.

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