Ventilation and exhaust system for residential buildings

Abstract

This invention relates to the field of ventilation and exhaust technology for residential buildings, specifically a ventilation and exhaust system for residential buildings, comprising: a main exhaust pipe and a main drain pipe connecting the kitchens and bathrooms on each floor, and branch exhaust pipes and branch drain pipes on each floor; the main exhaust pipe and the main drain pipe have upper and lower ends, and air inlets are provided between the indoor and outdoor areas on each floor. An exhaust device or exhaust purification device is installed at the upper end of the main exhaust pipe and the main drain pipe, or an exhaust device or exhaust purification device is installed at the lower end of the main exhaust pipe and the main drain pipe, or both the upper and lower ends of the main exhaust pipe and the main drain pipe are equipped with exhaust devices or exhaust purification devices. Simultaneously, a foul gas check valve is connected to the sewage network through a pipeline at the lower end of the main drain pipe to prevent cross-contamination of smoke, odors, backflow of odors, etc., between households, while also achieving fresh air exchange and reducing the occurrence of diseases.

Description

Technical Field

[0001] This invention belongs to the field of ventilation technology for residential buildings, and relates to aerodynamics, fluid mechanics, thermodynamics, etc., especially the air intake and stale gas exhaust system of residential buildings. Background Technology

[0002] Residential buildings are where people live and work. Indoor air quality in residential buildings is receiving increasing attention. Kitchens and bathrooms are two major sources of pollutants in residential buildings. To meet the needs of energy conservation and emission reduction, residential buildings are becoming smaller and more enclosed.

[0003] Effective ventilation is the fundamental solution to this problem. A good exhaust ventilation system is of great significance for creating good indoor air quality and improving the economic efficiency of ventilation system operation.

[0004] Modern residential buildings typically include kitchens and bathrooms. To address the issue of smoke and gas exhaust in these spaces, main exhaust ducts or flues and branch exhaust ducts are installed inside or outside the kitchen, with the branch exhaust ducts connecting to the main exhaust duct. Similarly, main and branch drain pipes are also installed inside or outside the bathroom, with the branch exhaust ducts connecting to the main exhaust duct. Main and branch drain pipes are also installed, with the branch drain pipes connecting to the main drain pipe. When there is little or no water flow through the main and branch drain pipes, the water pipes are in a gaseous state. The airflow in the exhaust ducts and the airflow in the drain pipes can interact and affect each other through poorly sealed check valves or floor drains, connecting with the kitchen and bathroom spaces.

[0005] Regarding the structural forms of exhaust ducts, U-shaped and T-shaped ducts are predominantly used in Europe and America, which are incompatible with the usage patterns of Chinese users. Furthermore, cooking methods and dietary habits in Europe and America differ significantly from those in my country, resulting in less oil fume production. Therefore, U-shaped and T-shaped exhaust ducts are not suitable for use in mid- to high-rise residential buildings in my country. In Japan, the most widely used method is a decentralized, bidirectional, through-flow horizontal exhaust system. Each floor has a horizontal flue connected to the kitchen's range hood or exhaust fan via a flexible hose. Caps are installed at both ends of the horizontal flue to prevent external airflow from affecting the exhaust. This exhaust method avoids mutual interference between adjacent floors. Moreover, both ends of the flue have openings, allowing for adjustments to wind pressure and direction by changing the flue outlet. This type of flue is suitable for high-rise buildings and areas with high wind pressure. However, it still suffers from the drawback of oily cooking fumes easily adhering to the building's exterior walls.

[0006] Currently in China, most residential buildings use centralized public exhaust systems for kitchens and bathrooms, with the exception of a very small number of individual direct exhaust systems. Direct exhaust systems offer lower resistance and higher air volume. However, in multi-story and high-rise buildings, cooking fumes from lower-floor residents can enter the interior through windows of upper or nearby units, causing cross-contamination. Furthermore, after a period of use, direct exhaust systems accumulate grease near the exhaust vents on the exterior walls, affecting the building's aesthetics. Therefore, direct exhaust systems have been largely phased out in mid- to high-rise residential buildings, with centralized public exhaust systems becoming the primary solution.

[0007] According to the power source and structure, there are three main types of public centralized exhaust systems: (1) Centralized top exhaust system: This system only installs roof exhaust fans at the top of the main exhaust pipe on the roof or rooftop, so that the shared main exhaust duct is kept under negative pressure, so that the gas that each household needs to exhaust can enter the main exhaust duct, which plays the role of drawing out the air. The disadvantages of this exhaust system are: First, the exhaust volume of the bottom households in mid-rise and high-rise residential buildings is small, while the exhaust volume of the top is large, and the bottom households still cannot get effective exhaust. This method is more suitable for single-story or ground-floor residential buildings. Second, when the exhaust volume of the main exhaust pipe is large and the drain sealing device in the kitchen and toilet is not sealed tightly, the odor in the drain pipe will be sucked into the room. (2) Mixed top exhaust system: This system is based on the centralized top exhaust system. In addition to installing roof fans on the roof, each household also installs exhaust fans or range hoods, which increases the capture capacity of kitchen fumes and bathroom gases, giving them more initiative. Its disadvantages are: First, for mid- to high-rise residential buildings, the higher the operating rate of each household's exhaust fan, the higher the static pressure in the bottom exhaust pipe, and the lower the bottom exhaust volume. There will be cross-contamination of smells and smoke between households below the pressure neutral plane. Second, when the main exhaust pipe has a large air volume and the drain sealing device in the kitchen and toilet is not sealed properly, the odor in the drain pipe will be sucked into the room. (3) Decentralized exhaust system: Compared with the mixed top exhaust system, the decentralized smoke exhaust system uses a non-powered wind cap on the roof. The exhaust mainly relies on the range hood or exhaust fan installed by each household. It is the most commonly used exhaust system at present. However, theoretical research and practice have proven that the following defects still exist: First, when the operating rate of the system is higher, the static pressure in the bottom exhaust pipe is higher and the bottom exhaust volume is smaller. At the same time, the smoke from the households that are turned on will cross-contamination into the households that are not turned on. When the external working conditions of the pipe change (such as changes in wind direction and pressure), problems such as cross-contamination of smells and insufficient exhaust volume in the lower floors still frequently occur. Second, when the main exhaust pipe has a large air volume, and when the drain sealing devices in the kitchen and toilet are not sealed properly, the odor in the drain pipe will be sucked into the room. In a paper titled "Analysis of Ventilation Performance Test of Residential Kitchen Exhaust Duct System" published in the March 2019 issue of the journal "Refrigeration and Air Conditioning" by Zhao Dan, Xu Zhaowei, and others from the National Air Conditioning Equipment Quality Supervision and Inspection Center and China Academy of Building Research Co., Ltd., it was revealed that: (1) The lower the floor corresponding to the main exhaust pipe, the higher the static pressure in the exhaust pipe, and the higher the floor, the lower the static pressure in the exhaust pipe. (2) The higher the operating rate of the range hood, the higher the static pressure in the exhaust pipe; the lower the average exhaust volume of each floor.

[0008] Installing an exhaust fan at the upper end of the exhaust pipe is a common practice, especially for low- and mid-rise residential buildings. A high-powered exhaust fan can generally maintain the negative pressure requirements within the main exhaust duct. For example, industry standards such as JG / T194-2006 ("Residential Kitchen Exhaust Duct"), JGJ / T455 ("Technical Standard for Residential Exhaust Pipeline System Engineering"), and 19CYH03 ("Design and Application Atlas of Technical Standard for Residential Exhaust Pipeline System Engineering") all require the installation of an exhaust device at the upper end of the exhaust duct on the roof. Similarly, Chinese patents such as "A Multi-Story Residential Exhaust System" (application number 202123455569.1) and "A Multi-Story Residential Exhaust System and Its Control Method" (application number 202111665015.6) also follow this practice. For high-rise or super high-rise residential buildings, installing exhaust devices only at the rooftop duct outlets leaves the pressure in the exhaust pipes of the lower floors still relatively high, the airflow velocity low, and the exhaust volume small. This results in significant pressure unevenness within the exhaust pipes, frequently leading to backdrafts and cross-contamination of odors, especially when the drain seals are not tight, causing foul odors from the drain pipes to be drawn into the rooms. For example, Chinese patent application number 201921520267.8, "A Smoke Exhaust Duct Fresh Air System," connects a duct system to the bottom of the common smoke duct. The bottom of this duct system is connected to a ductwork device containing a blower that directs airflow into the common smoke duct rather than exhausting it outwards. This technical solution provides some jet-like airflow guidance for the airflow in the lower-level kitchens or bathrooms, but increases static pressure in the main ducts of the middle and upper floors, hindering exhaust in those areas. Furthermore, the above method still cannot solve the problem of foul odors from the drain pipes being drawn into the rooms when the main exhaust duct has a large suction volume or when the drain seals in the kitchens and toilets are not tight.

[0009] To address the uneven distribution of smoke exhaust across floors, a paper by Zhai Changxiu published on CNKI, titled "Research on Centralized Smoke Exhaust Systems in Multi-Story Residential Buildings," proposes two solutions: First, optimize the exhaust volume of the lower floors by installing high-volume, high-pressure range hoods on the branch exhaust pipes of lower-floor units and low-volume, low-pressure range hoods on the branch exhaust pipes of upper-floor units. Second, increase the opening of the check valves on the branch exhaust pipes of lower-floor units and decrease the opening of the check valves on the branch exhaust pipes of upper-floor units, thereby changing the resistance coefficient to optimize the uniformity of exhaust volume within the smoke exhaust duct. Both solutions involve highly complex control systems, high costs, and low reliability, making them extremely difficult to implement in practice. Furthermore, they fail to address the issue of foul odors from the sewer pipes being drawn into the rooms when the main exhaust pipe has a high exhaust volume or when the drainage sealing devices in the kitchen and toilets are not properly sealed.

[0010] To address the issues of odor and smoke cross-contamination, in addition to the methods mentioned above, various measures have been taken from within the exhaust duct itself. These include installing mother-daughter type flues, variable pressure flues, and variable cross-section flues. For example, the induction device installed at the air inlet of the exhaust duct, jointly developed by the Air Conditioning Research Institute of the China Academy of Building Research and Beijing Ju'an Building Materials Co., Ltd., has achieved some improvement. However, it still does not fundamentally solve the problems of sewer backflow odors, smoke cross-contamination when the range hood is frequently used, and the high pressure and slow airflow in the lower-level flue. It also fails to resolve the issue of foul odors from the sewer pipes being drawn into the room when the main exhaust pipe has a large suction volume or when the drain seals in the kitchen and toilet are not tight, resulting in the inhalation of odors from the sewer pipes into the room.

[0011] The existing negative pressure residential fresh air system has a significant effect on improving indoor air quality. It can achieve a negative pressure state in the room relative to the outside atmosphere. However, the research and application of negative pressure residential fresh air systems are generally based on separate installation systems for each household, that is, the exhaust system is an independent system for each household. In a multi-story or high-rise residential building, some households have installed the system while others do not. The following shortcomings still exist: (1) When the drain or drain valve leaks, the polluted gas in the sewer will also enter the room under the negative pressure in the room. (2) If the adjacent household A has installed a fresh air system and turned it on, while another household B has installed a fresh air system but does not turn it on or has not installed a fresh air system, when the one-way valve is not sealed tightly, the polluted gas from household A will enter household B through the exhaust duct. (3) To ensure that each household is in a negative pressure state, each household needs to install a negative pressure fresh air system and ensure that each household is turned on and running at the same negative pressure value. Since the efficiency of the small-power fans in each household is extremely low, this also causes the problem of high energy consumption.

[0012] In studying the ventilation problems of kitchens and bathrooms, we found that: (1) People pay more attention to the structural problems of the ventilation duct itself and the ventilation problems of a single household, and pay very little attention to the mutual influence between the ventilation duct and the sewer and the ventilation problems of the whole building. Practice and theoretical analysis have proven that even if the problems of cross-contamination of odors, smoke and backflow of the ventilation duct are solved, the problem of backflow of odors from the sewer into the room still exists; solving the ventilation problem of only one household cannot solve the ventilation problem of all households in the whole building. (2) People pay more attention to installing ventilation devices only at the upper end of the main exhaust pipe, and pay less attention to the ventilation problems at the lower end of the main exhaust pipe, the lower end or the upper end of the main sewer pipe. Perhaps because people are used to considering the chimney effect of traditional high temperature differences (200℃~400℃) in boilers and rural coal and firewood combustion, they have overlooked the fact that the chimney effect is negligible when the temperature difference between the main exhaust pipe and the outside is extremely small (3℃~6℃) when cooking with gas in modern homes, or when a negative temperature difference (-1℃~-10℃ in summer) occurs, backflow occurs. Therefore, very few studies have been conducted on the effect of sealing the upper end of the exhaust pipe and installing an exhaust device or exhaust purification device at the lower end of the main exhaust pipe.

[0013] In summary, the phenomena of cross-contamination of smoke, odor, backflow of odor, and smoke in residential buildings are mainly manifested in the following working conditions: (1) The chimney effect of the exhaust pipe in modern residential buildings is not obvious. Since most modern houses use gas or electric heating, the temperature in the exhaust pipe is not high, generally about 3-6℃ higher than the temperature in the kitchen, and the chimney effect is minimal. The temperature in the exhaust pipe is sometimes higher than the outdoor ambient temperature (such as in winter), and sometimes lower than the outdoor temperature (such as in summer, especially when the house is equipped with air conditioning). The higher the air temperature, the lower the air density and the lower the static pressure. When the flue gas temperature in the main exhaust pipe is lower than the indoor temperature (such as in summer), the air density in the main exhaust pipe is higher and the static pressure is higher, and cross-contamination of odor and smoke often occurs between floors. (2) When the wind direction at the exhaust port at the upper end of the main exhaust pipe blows tangentially into the exhaust port or the wind pressure at the exhaust port is high, the phenomenon of backflow or reverse flow of smoke will occur. (3) When the indoor air pressure is lower than the air pressure in the pipe, the foul gas in the flue and sewer will flow back into the room, resulting in backflow of smoke and backflow of odor. (4) When the exhaust fan in the kitchen and bathroom is turned on, negative pressure will appear in the kitchen and bathroom. If the one-way valve in the sewer is not sealed tightly, the foul gas in the sewer will enter the room. (5) When the range hoods on each floor are turned on at a high rate, the lower floors will experience poor exhaust or backflow of smoke. (6) When there is a cross breeze in the room, the indoor air pressure will be lower than the pressure in the exhaust pipe and sewer, often resulting in backflow of odor and smoke. (7) When the weather is cloudy and rainy, the atmospheric and indoor air pressure will decrease, and backflow of odor from the sewer will often occur during cloudy and rainy weather. (8) When the neighboring household A has installed a fresh air system and turned it on, and another household B has installed a fresh air system but does not turn it on or has not installed a fresh air system, if the one-way valve is not sealed tightly, the foul gas in household A will enter household B through the exhaust pipe.

[0014] In summary, due to factors such as indoor and outdoor temperatures and pressures, wind direction and speed on the roof, exhaust pipe size and drag coefficient, exhaust system performance and operating rate, and the location of the pressure neutral surface, all known exhaust structures and systems, under certain operating conditions, generally experience issues such as cross-contamination of odors and smoke, backflow, reverse odors, and accumulation of indoor cooking fumes and odors. The presence of polluted gases and virus-carrying gases indoors or their cross-contamination between floors seriously impacts people's health and quality of life. Summary of the Invention

[0015] The purpose of this invention is to provide a new ventilation and exhaust system for residential buildings, which can fundamentally solve the problems of cross-contamination of odors, smoke, backflow, and oily fumes between different floors and between floors in residential buildings, while achieving fresh air exchange in the room.

[0016] To achieve the above objectives, the present invention provides the following technical solution: A ventilation and exhaust system for a residential building includes: a main exhaust pipe and branch exhaust pipes for each floor, respectively installed in or outside the kitchens and bathrooms on each floor of the residential building; the main exhaust pipe and the main exhaust pipe each have an upper end and a lower end; each branch exhaust pipe has two ports, one port being connected to the main exhaust pipe and the other port being connected to the interior or equipped with a smoke trap, an exhaust device, or a flow regulating valve or a combination thereof and connected to the interior; or the branch exhaust pipe is equipped with a fireproof check valve, a fireproof valve, a check valve, or a flow regulating valve or a combination thereof; the lower end of the main exhaust pipe is connected to a sewage network and a septic tank; each branch exhaust pipe has two ports, one port being connected to the main exhaust pipe and the other port being connected to the space of the kitchen or bathroom or to the outlet of a backflow preventer. The water inlet is connected to the space of the kitchen and bathroom; each kitchen and bathroom on each floor is provided with an air inlet between itself and the outside or between itself and the outside through the indoor space. The air inlet is connected to the atmosphere or is equipped with an air purifier, a volume regulating valve, an air intake fan, or a fresh air device with a heat exchanger or a combination thereof. The feature is that an exhaust device or an exhaust purification device is connected to the upper end of the main exhaust pipe and the upper end of the main drain pipe of the kitchen and bathroom. The exhaust device or exhaust purification device is provided with an air inlet and an exhaust outlet. The upper end of the main exhaust pipe and the upper end of the main drain pipe of the kitchen and bathroom are connected to the air inlet of the exhaust device or exhaust purification device. The exhaust outlet is connected to the outdoor atmosphere. At the same time, a check valve or a water seal valve is connected between the lower end of the main drain pipe and the sewage network through a pipeline.

[0017] In this application, the main exhaust pipe and main drain pipe include: one main exhaust pipe per household, one main drain pipe per household, or multiple main exhaust pipes per household, or multiple main drain pipes per household (such as a centralized exhaust pipe and centralized drain pipe for multiple kitchens, multiple bathrooms, and a separate laundry room in one household). The backflow prevention device includes: a floor drain, a water trap, a backflow check valve, or a siphon bend for toilets, etc.

[0018] The upper ends of the main exhaust pipes and main drain pipes in the kitchen and bathroom are connected to exhaust devices or exhaust purification devices. This includes situations where a residential building has multiple main exhaust pipes and multiple main drain pipes. In this case, the upper ends of the main exhaust pipes and main drain pipes can be connected to exhaust devices or exhaust purification devices respectively, or the upper ends of the main exhaust pipes and main drain pipes can be connected to exhaust devices or exhaust purification devices through a pipeline, or a portion of the upper ends of the main exhaust pipes and main drain pipes can be independently connected to exhaust devices or exhaust purification devices, and a portion can be connected to exhaust devices or exhaust purification devices through a pipeline. A fire damper can be installed between the upper end of the main exhaust pipe and the exhaust device or exhaust purification device.

[0019] This technical solution ensures that the main exhaust pipe and main drain pipe are under negative pressure relative to the indoor environment. This differs from existing technical solutions that only install exhaust devices or exhaust purification devices at the upper end of the main exhaust pipe.

[0020] In this application, the check valve or water seal valve (similar to the air-sealing principle of a toilet) functions to prevent foul gas from the sewage network or septic tank from entering the main sewer pipe, while ensuring unobstructed sewage discharge from the main sewer pipe. The exhaust purification device can both exhaust gas and purify foul gas. This technical solution is applicable to exhaust pipes of various structural forms.

[0021] In this application, the exhaust device or exhaust purification device is a ventilation or ventilation purification device with an air inlet and an air outlet. It can be a natural power exhaust device based on wind power, solar energy, or thermal buoyancy (such as various exhaust caps), or an electric exhaust device or electric exhaust purification device, or a hybrid exhaust device or exhaust purification device combining natural power and electric power. Electric exhaust devices include various axial flow, diagonal flow, and centrifugal fans, with negative pressure fans being preferred. The flue gas collector is a hood that collects flue gas only under pressure difference, including flue gas collection devices that do not have their own powered exhaust fan or have their own powered exhaust fan.

[0022] The total exhaust volume of all exhaust fans or exhaust purification devices must ensure negative pressure in all pipes. Experiments have shown that even without installing drains and bathroom exhaust fans, sewage gases from the sewers will not enter the room using this technical solution.

[0023] The residential buildings described in this invention refer to buildings with kitchens or bathrooms, or both, used for people's daily living. These include: residences, villas, dormitories, apartments, hotels, inns, sanatoriums, and other residential buildings.

[0024] One possible technical solution for the ventilation and exhaust system of a residential building described above is as follows: a vent is provided at the lower end of the main exhaust pipe in the kitchen and bathroom. An exhaust device or exhaust purification device is installed at the vent via a connecting pipe. The exhaust device or exhaust purification device has an air inlet and an air outlet. One end of the connecting pipe is connected to the vent at the lower end of the main exhaust pipe, and the other end is connected to the air inlet of the exhaust device or exhaust purification device. The lower end of the main exhaust pipe includes its side surface and cross-section.

[0025] This technical solution, by simultaneously installing an exhaust device or exhaust purification device at the lower end of the main exhaust pipe and at the upper ends of both the main exhaust pipe and the main drain pipe, can not only significantly improve the uniformity of gas flow velocity within the pipes and reduce the unevenness of pressure difference between exhaust pipes and indoor spaces on different floors, but also improve system efficiency. Its function is to reduce the static pressure within the exhaust pipes and main drain pipes on each floor, effectively solving the problem of high static pressure, low exhaust velocity, and uneven exhaust volume on different floors in the main exhaust pipes and main drain pipes of mid- to high-rise residential buildings (see appendix for details). Figure 10 The measured curve ⑤ and curves ①, ②, ③, and ④ show the problems of cross-contamination of smoke, flavor, reverse odor, and backflow of smoke. As long as the exhaust fan has sufficient suction capacity, even if all exhaust fans on each floor are turned on or partially turned on, there will be no cross-contamination of smoke, flavor, reverse odor, or backflow of smoke.

[0026] The above-mentioned ventilation and exhaust system for a residential building can be configured as follows: the lower ends of multiple main exhaust pipes of multiple units in a residential building can be connected by pipelines and connected to an exhaust device or exhaust purification device at a certain distance from the building; the lower ends of multiple main drain pipes (or sewage pipes or greywater drainage pipes of bathrooms) of multiple units in a residential building can be connected and connected to a check valve or water seal valve device at a certain distance from the building.

[0027] One possible technical solution for the ventilation and exhaust system of a residential building is as follows: A connecting pipe is connected upwards to the lower port of the main drain pipe between the lower end of the main drain pipe and the check valve or water seal valve. An exhaust valve or automatic water-blocking exhaust valve is installed at the upper port of this connecting pipe. The exhaust valve or automatic water-blocking exhaust valve has an air inlet and an exhaust outlet, and the air inlet is connected to the upper port of the connecting pipe. The exhaust valve or automatic water-blocking exhaust valve is a device that allows only gas to pass through, not liquid. Its function is to prevent sewage in the main drain pipe from being discharged to the outside of the drain pipe through the exhaust valve or automatic water-blocking exhaust valve when the check valve, water seal valve, or sewage network is blocked. Simultaneously, it allows polluted gas in the main drain pipe under normal conditions to be discharged through the automatic water-blocking exhaust valve or exhaust valve.

[0028] One possible technical solution for the ventilation and exhaust system of a residential building described above is as follows: The exhaust port of the exhaust valve or automatic water-proof exhaust valve is connected to the air inlet of the exhaust device or exhaust purification device at the lower end of the main exhaust pipe via a pipeline. The exhaust port of the exhaust device or exhaust purification device at the lower end of the main exhaust pipe is connected to the atmosphere or to a sewage network via a pipeline. This technical solution allows for simultaneous exhaust or exhaust purification at the upper and lower ends of both the main exhaust pipe and the main drain pipe. This not only significantly improves the uniformity of gas flow velocity within the pipe and reduces the unevenness of pressure difference between the exhaust pipe and the indoor environment between different floors, but also improves the system efficiency. It is particularly suitable for high-rise or ultra-high-rise residential buildings.

[0029] One possible technical solution for the ventilation and exhaust system of a residential building is to install an exhaust device or an exhaust purification device on the exhaust port of the exhaust valve or automatic water-proof exhaust valve.

[0030] One possible technical solution for the ventilation and exhaust system of a residential building is to install an exhaust device or exhaust purification device via a pipeline near the pressure neutral plane at the midpoint of the vertical height of the main exhaust pipe. The neutral plane refers to a virtual horizontal plane where the internal pressure of the building is essentially equal to the external pressure. This technical solution can further reduce the static pressure in the exhaust pipe, especially in high-rise and super high-rise buildings, corresponding to the exhaust pipe near the neutral plane, further equalize the exhaust volume of each floor, and prevent backflow of smoke in kitchens and bathrooms near the neutral plane. It is particularly suitable for high-rise or super high-rise buildings. The exhaust device or exhaust purification device can be installed inside the equipment floor, in the safety refuge floor, or outside the building wall.

[0031] A ventilation and exhaust system for a residential building includes: a main exhaust pipe and branch exhaust pipes for each floor, respectively installed in or outside the kitchen and bathroom on each floor of the residential building; the main exhaust pipe and the main exhaust pipe are respectively provided with an upper end and a lower end; each branch exhaust pipe has two ports, one port being connected to the main exhaust pipe and the other port being connected to the interior or equipped with a smoke trap, an exhaust device, or a flow regulating valve or a combination thereof and connected to the interior; or the branch exhaust pipe is equipped with a fireproof check valve, a fireproof valve, a check valve, or a flow regulating valve or a combination thereof; the lower end of the main exhaust pipe is connected to a sewage network and a septic tank; each branch exhaust pipe has two ports, one port being connected to the main exhaust pipe and the other port being connected to the space of the kitchen or bathroom or connected to a backflow preventer. The device's outlet is connected, and the inlet of the backflow preventer is connected to the space of the kitchen and bathroom. Each floor's kitchen and bathroom is connected to the outside or, through an indoor space, to the outside. The air inlets are connected to the atmosphere or equipped with an air purifier, airflow regulating valve, air intake fan, or a fresh air system with a heat exchanger, or a combination thereof. The upper end of the main exhaust pipe of the kitchen and bathroom is sealed. A vent is opened at the lower end of the main exhaust pipe, and an exhaust device or exhaust purification device is connected to the vent via a pipe. The exhaust device or exhaust purification device has an air inlet and an exhaust outlet. The vent is connected to the air inlet of the exhaust device or exhaust purification device via a pipe. A check valve or water seal valve is connected between the lower end of the main drain pipe and the sewage network via a pipe. This technical solution is applicable to systems where the upper end of the main drain pipe is open, or where an exhaust device or exhaust purification device is installed at the upper end of the main drain pipe, or where the upper end of the main drain pipe is closed. This technical solution can also be a system that connects the upper end of the main exhaust pipe to the upper end of the main drain pipe via a pipeline.

[0032] This technical solution, by sealing the upper ends of the main exhaust pipe and main drain pipe, prevents air from entering through the upper ports, thus increasing the negative pressure within the pipes. Actual testing comparing installing an exhaust device or exhaust purification device only at the lower port of the main exhaust pipe with installing an exhaust device of the same power only at the upper port of the main exhaust pipe demonstrates that installing an exhaust device only at the lower port of the main exhaust pipe effectively removes indoor smoke (see appendix for details). Figure 10 Measured curves ①, ②, ③, and ④), and it can facilitate the installation and maintenance of exhaust devices or exhaust purification devices, reducing the impact of exhaust fan vibration and noise on residents.

[0033] One possible technical solution for the ventilation and exhaust system of a residential building is as follows: a lower port of a connecting pipe is connected upwards on the pipe between the lower end of the main drain pipe and the check valve or water seal valve. An exhaust valve or an automatic water-blocking exhaust valve is installed on the upper port of the connecting pipe. The exhaust valve or the automatic water-blocking exhaust valve is provided with an air inlet and an exhaust outlet. The air inlet is connected to the upper port of the connecting pipe.

[0034] For any of the above-mentioned ventilation and exhaust systems for residential buildings, the available technical solutions are: to seal the upper end of the main drain pipe, and to connect the exhaust port of the exhaust valve or automatic water-proof exhaust valve to the air inlet of the exhaust device or exhaust purification device at the lower end of the main exhaust pipe through a pipeline, wherein the exhaust port of the exhaust device or exhaust purification device is connected to the atmosphere or connected to the sewage network through a pipeline.

[0035] For any of the above-mentioned ventilation and exhaust systems for residential buildings, the available technical solutions are: sealing the upper end of the main drain pipe and installing an exhaust device or exhaust purification device on the exhaust port of the exhaust valve or automatic water-proof exhaust valve.

[0036] For any of the aforementioned ventilation and exhaust systems in residential buildings, a possible technical solution is to install an exhaust device or exhaust purification device via a pipeline near the pressure neutral plane at the midpoint of the vertical height of the main exhaust pipe. The exhaust device or exhaust purification device can be installed within the equipment floor, the safety refuge floor, or outside the building wall.

[0037] For any of the aforementioned ventilation and exhaust systems in residential buildings, a possible technical solution is to create a vent hole on the side of the upper end of the main exhaust pipe in the kitchen or bathroom, and to install an exhaust device or exhaust purification device through the vent hole on the side of the upper end of the main exhaust pipe. Creating a vent hole on the side of the upper end of the main exhaust pipe reduces the use of bends and facilitates installation.

[0038] For any of the aforementioned ventilation and exhaust systems in residential buildings, a viable technical solution is to install an exhaust device and a gas purification device, or an integrated exhaust purification device, at the ends of each main exhaust pipe and each main drain pipe. The gas purification device effectively filters and purifies the polluted gas discharged from the exhaust device, preventing secondary pollution. The selection of the gas purification device at the outlet of the main exhaust pipe and main drain pipe should be based on the composition and content of pollutants in the exhaust gas. The gas purification device can be installed at the air inlet or outlet of the exhaust device. The gas purification device includes waste gas purification devices or odor purification devices, etc. In this case, the air purification device can share a single exhaust fan with the main exhaust pipe and main drain pipe; that is, the fan on the air purification device can replace or share a single exhaust fan with the exhaust fans on the main exhaust pipe and main drain pipe.

[0039] For any of the aforementioned ventilation and exhaust systems in residential buildings, a possible technical solution is to connect the outlet of the exhaust device or exhaust purification device at the lower end of the main exhaust pipe to the sewage network via a pipe. This technical solution transports polluted gas into the sewage network, further reducing air pollution around the residential building.

[0040] For any of the above-mentioned ventilation and exhaust systems of residential buildings, the available technical solutions are as follows: an air inlet is provided between the kitchen / bathroom and the outside or through other parts of the building and the outside; the air inlet is equipped with an air volume regulating filter valve or a positive pressure intake fan or a bidirectional flow fresh air fan with a total heat exchanger; the air volume regulating filter valve can be manual or an electric air valve with automatic timer control or an electric air supply fan with an air valve; the positive pressure intake fan or the bidirectional flow fresh air fan with a total heat exchanger is an intelligent fan with automatic timer control based on indoor gas quality indicators and pressure difference indicators.

[0041] For any of the aforementioned ventilation and exhaust systems in residential buildings, a suitable technical solution is as follows: the exhaust device is a purely electric exhaust device or a hybrid exhaust device combining natural power and electric power, with a cyclic timer switch connected to the power line of the purely electric or hybrid exhaust device. In this technical solution, the cyclic timer switch connected to the power line of the electric exhaust device allows for setting the automatic start-up and shutdown times of the exhaust device as needed, and it can automatically cycle on and off daily, saving operating costs and reducing noise during rest periods. Multiple electric exhaust devices can be connected to multiple cyclic timers via relays, or they can be connected to a single cyclic timer switch via relays.

[0042] For any of the above-mentioned ventilation and exhaust systems for residential buildings, the available technical solutions are as follows: the exhaust device is a pure electric exhaust device or a hybrid exhaust device combining a natural power exhaust device and an electric exhaust device; a time-delay control switch based on wind speed, pressure, or differential pressure is connected to the power line of the pure electric exhaust device or the hybrid exhaust device; the wind speed sensor or pressure sensor using the wind speed or pressure time-delay control switch is installed at the top inside the main exhaust pipe or the main drain pipe; the high-pressure end of the differential pressure sensor using the time-delay control switch is installed indoors or outdoors, and the low-pressure end is installed at the top inside the main exhaust pipe or the main drain pipe. In this technical solution, wind speed, pressure, or differential pressure sensors installed inside the main exhaust pipe, the top of the main drain pipe, or indoors can monitor the exhaust speed or pressure at the top of the main exhaust pipe or the main drain pipe, or monitor the pressure difference between the main exhaust pipe or the main drain pipe and the indoor or outdoor environment. When, under the combined action of natural wind, thermal pressure within the pipe, and the electric exhaust device, the wind speed, pressure, or differential pressure sensor detects that the exhaust speed at the top of the exhaust pipe or the main drain pipe exceeds a certain set value, or the indoor pressure exceeds a certain set value, or the pressure difference between the indoor environment and the top of the exhaust pipe or the main drain pipe exceeds a certain set value, or the pressure difference between the outdoor environment and the top of the pipe or the main drain pipe exceeds a certain set value, the delay control switch will disconnect after a certain delay, and the electric exhaust device will stop operating. At this time, the exhaust task is completed by natural wind and thermal pressure at the top of the exhaust pipe or the main drain pipe. The delayed disconnection of the main circuit can prevent the electric exhaust device from frequently starting the motor when there are small fluctuations in wind speed, pressure, or differential pressure values, which could cause the motor to burn out. When the exhaust wind speed at the top of the exhaust pipe or main drain pipe is less than a certain set value, or the indoor pressure is less than the pressure at the top of the exhaust pipe or main drain pipe, or the pressure difference between the indoor area and the top of the exhaust pipe or main drain pipe is less than a certain set value, the delay control switch closes and starts the electric exhaust device to ensure that the exhaust pipe and drain pipe are always in a negative pressure state, eliminating the phenomenon of cross-contamination, backflow, and odor of flue gas.

[0043] For any of the above-mentioned ventilation and exhaust systems in residential buildings, the available technical solutions are: the exhaust fan control mode can also be based on the type and concentration of polluted gas or based on time interval requirements.

[0044] For any of the aforementioned residential building ventilation and exhaust systems, a suitable technical solution is as follows: The main exhaust pipes corresponding to each floor or some of the floors are connected to the main drainage pipes of each floor via connecting pipes. One-way valves are installed on the connecting pipes, and these valves can open towards the main drainage pipes. When a water column flows downwards in the main drainage pipes, the flowing water column acts as a suction piston, drawing in polluted gas from the main exhaust pipes along with sewage from the main drainage pipes, which then flows into the sewage network. The check valve's backflow prevention function prevents sewage from the drainage pipes from flowing into the exhaust pipes.

[0045] For any of the above-mentioned ventilation and exhaust systems in residential buildings, the available technical solution is as follows: a differential pressure switch is installed between the branch exhaust pipe on each floor or the corresponding main exhaust pipe on each floor and the room. The differential pressure switch is connected to the input power of the range hood or exhaust fan on each floor. When the pressure difference between the indoor pressure and the pressure in the exhaust pipe is lower than a certain set value, the range hood or exhaust fan automatically starts to exhaust.

[0046] For any of the above-mentioned ventilation and exhaust systems in residential buildings, the available technical solutions are: each bedroom and main hall has an air inlet, the air inlet is open or is equipped with a positive pressure fresh air device, and the fresh air device can automatically adjust the air intake volume.

[0047] For any of the aforementioned residential building ventilation and exhaust systems, a suitable technical solution is as follows: A total heat exchange bidirectional flow fresh air unit is installed indoors. The exhaust outlet of the bidirectional flow fresh air unit is connected to the main exhaust pipe, the intake outlet of the bidirectional flow fresh air unit is connected to the relevant rooms, and each fresh air inlet of the bidirectional flow fresh air unit is connected to the outside. Fresh air outlets are distributed in each relevant room. This technical solution can achieve a mixed exhaust and ventilation system with both positive and negative pressure, and can also recover heat or cooling from the living space.

[0048] For any of the aforementioned ventilation and exhaust systems in residential buildings, a suitable technical solution is that a branch exhaust pipe on the main exhaust pipe is equipped with an airflow regulating valve. The airflow regulating valve can be manual or automatic, or it can be electrically remote-controlled or automatically timed based on indoor gas quality indicators and pressure difference indicators, and is linked to an electric exhaust device or a smart range hood.

[0049] For any of the above-mentioned ventilation and exhaust systems for residential buildings, the available technical solution is to install an on / off valve at the lower end of the main exhaust pipe, which can be used to clean oil and debris inside the main exhaust pipe.

[0050] For any of the above-mentioned ventilation and exhaust systems for residential buildings, the available technical solutions are: the power source for the electric exhaust device or exhaust purification device can be grid power, photovoltaic power, wind power, or a power source that can feed back to the grid in a complementary manner with photovoltaic power, wind power, and grid.

[0051] For any of the aforementioned ventilation and exhaust systems in residential buildings, a suitable technical solution is to have exhaust pipes connected to the main exhaust pipe in the living room, bedroom, and study. These exhaust pipes can achieve uniform exhaust in all main rooms.

[0052] For any of the aforementioned ventilation and exhaust systems in residential buildings, a suitable technical solution is to connect the outlet of the exhaust device or exhaust purification device at the lower end of each main exhaust pipe to the sewage pipe network via a pipeline. Maintenance manhole covers on the sewage pipe network should be properly sealed.

[0053] For any of the above-mentioned ventilation and exhaust systems for residential buildings, the available technical solutions are: an exhaust pipe is connected to a sewage pipe network located away from the residential building, and the exhaust pipe can be open or equipped with an exhaust purification device at its upper port.

[0054] Beneficial effects: When the power performance, exhaust volume and exhaust pressure of the exhaust device or exhaust purification device are matched with the residential volume and cross-sectional area of ​​the exhaust pipe, the above technical solution can eliminate the phenomenon of cross-contamination of smoke, odor, backflow of smoke and odor in kitchens and bathrooms of one's own home or between households and floors, thereby reducing the risk of virus transmission and infection, and achieving fresh air exchange. Attached Figure Description

[0055] Figure 1 This is a basic structural diagram of a ventilation and exhaust system for a residential building, wherein the upper ends of the main exhaust pipe and the main drain pipe are connected to the exhaust device in an upward exhaust mode, and the lower end of the main drain pipe is connected to the sewage network via a pipeline with a water seal valve.

[0056] Figure 2 This is a basic structural diagram of a ventilation and exhaust system for a residential building, wherein the upper end of the main exhaust pipe is closed and the lower end is connected to an exhaust device, and the lower end of the main drain pipe is connected to the sewage network via a pipeline with a water seal valve. Figure 3 The diagram illustrates the basic structural principle of a ventilation and exhaust system for a residential building, where the upper port of the main exhaust pipe is connected to the upper port of the main drain pipe, and an electric exhaust fan and a gas purifier are connected to it. The lower port of the main exhaust pipe is connected to the electric exhaust fan in both upper and lower exhaust modes, and a check valve is connected to the lower end of the main drain pipe and the sewage network via a pipeline.

[0057] Figure 4 The diagram illustrates the basic unit structure of a ventilation and exhaust system for a residential building, wherein the upper ends of the main exhaust pipe and the main drain pipe are respectively equipped with exhaust fans, the main drain pipe is equipped with an automatic water-blocking exhaust valve and an exhaust fan, and the lower end of the main drain pipe is connected to the sewage network via a pipeline with a water seal valve.

[0058] Figure 5 The diagram illustrates the basic unit structure of a ventilation and exhaust system for a residential building, comprising a closed upper port of the main exhaust pipe and a closed upper port of the main drain pipe, an exhaust fan and a gas purifier at the lower port of the main exhaust pipe, an automatic water-blocking exhaust valve and an exhaust purification device at the lower end of the main drain pipe, and a water seal valve connected to the sewage network at the lower end of the main drain pipe via a pipeline.

[0059] Figure 6The diagram illustrates the basic unit structure of a ventilation and exhaust system for a residential building. The system connects the upper port of the main exhaust pipe to the upper port of the main drain pipe, which is then connected to an electric exhaust fan and a gas purifier. A connecting pipe connects the lower port of the main exhaust pipe to the lower port of the main drain pipe, and an automatic water-blocking exhaust valve is connected in series on the connecting pipe. A one-way valve is also connected between the lower end of the main drain pipe and the sewage network via a pipeline.

[0060] Figure 7 This is a basic structural diagram of a ventilation and exhaust system for a residential building that combines exhaust from multiple kitchens and multiple bathrooms, according to the present invention.

[0061] Figure 8 This is a schematic diagram of the ventilation and exhaust system for a residential building, based on the principle of controlling the switching of the exhaust device according to the wind speed inside the exhaust pipe.

[0062] Figure 9 This is a block diagram illustrating the control principle of a ventilation and exhaust system for a residential building, based on the pressure difference between the inside and outside of the exhaust pipe to control the switching of the exhaust device.

[0063] Figure 10 This is a comparison chart of the pressure difference test curves between the interior and exhaust pipe of an 18-story building using the technology of this invention and using the prior art.

[0064] Figure label: The above Figure 1 In the diagram: 1-Kitchen or bathroom, 2-Main exhaust pipe of kitchen or bathroom, 3-Branch exhaust pipe, 3a-Branch exhaust pipe check valve, 4-Main drain pipe of kitchen or bathroom, 5-Branch drain pipe, 6-Exhaust device at the upper port of main exhaust pipe, 24-Connecting pipe, 10-Smoke trap or exhaust fan, 11-Floor drain, 12-Air inlet, 13-Water seal valve, 13a-Water seal valve body, 13b-Water seal valve maintenance cover, 13c-Water seal valve outlet bend, 13d-Water seal valve debris removal valve, 13e-Water seal valve inlet. Dashed lines with arrows represent the direction of gas flow, and solid lines with arrows represent the direction of water and debris flow.

[0065] The above Figure 2In the diagram: 1-Kitchen or bathroom, 2-Main exhaust pipe of kitchen or bathroom, 3-Branch exhaust pipe, 3a-Branch exhaust pipe check valve, 4-Main drain pipe of kitchen or bathroom, 5-Branch drain pipe, 6a-Sealing plate at the upper end of main exhaust pipe, 7-Exhaust device at the lower end of main exhaust pipe, 7c-Protective net at the lower end of main exhaust pipe, 8-Exhaust device at the upper end of main drain pipe, 10-Smoke trap or exhaust fan, 11-Floor drain, 12-Air inlet, 13-Water seal valve, 13a-Water seal valve body, 13b-Water seal valve maintenance cover, 13c-Water seal valve outlet bend, 13d-Water seal valve debris removal valve, 13e-Water seal valve inlet, 50-Connecting pipe. Dashed lines with arrows represent the direction of gas flow, and solid lines with arrows represent the direction of water and debris flow.

[0066] The above Figure 3 In Chinese: 13-Pollution gas check valve, 7b-Main exhaust pipe lower port gas purifier, 68-Combined exhaust fan, 69-Combined gas purification device. Other numbers and names are the same. Figure 1 , Figure 2 .

[0067] The above Figure 4 In the middle: 6-Exhaust device at the upper port of the main exhaust pipe, 7a-Check valve at the lower port of the main exhaust pipe, 9-Exhaust fan at the lower port of the main drain pipe, 14-Automatic water-proof exhaust valve, 14a-Floor float of the automatic water-proof exhaust valve, 14b-Valve plate of the automatic water-proof exhaust valve, 14c-Air inlet of the automatic water-proof exhaust valve, 14d-Exhaust port of the automatic water-proof exhaust valve, 14e-Connecting pipeline, other numbers and names are the same. Figure 1 , Figure 2 , Figure 3 .

[0068] The above Figure 5 In Chinese: 8a - Main drain pipe upper port sealing plate; 9a - Main drain pipe lower port gas purification device. Other numbers and names are the same. Figure 1 , Figure 2 , Figure 3 , Figure 4 .

[0069] The above Figure 6 In Chinese: 16-Gas connecting pipe, 16a-Water-gas connecting pipe, other numbers and names are the same. Figures 1-5 .

[0070] The above Figure 7 Chinese: Number and name are the same Figures 1-6 .

[0071] The above Figure 815- Hybrid exhaust system combining natural and electric power, 15a- Natural exhaust cap, 15b- Electric motor, 15c- Impeller, 2- Main exhaust pipe, 17- Wind speed delay control switch, 18- Wind speed sensor head, 19- Infinite cycle timer switch, 20- 220V AC power supply.

[0072] The above Figure 9 In the middle: 24-Differential pressure delay control switch, 21-Low pressure sensor head, 22-High pressure sensor head, 23-Relay, 20-220V AC power supply. Other numbers and names are the same. Figure 8 .

[0073] The above Figure 10 In the diagram: Curve ① is a diagram showing the relationship between floor level and pressure difference in an existing technical solution A. Curve ② is a diagram showing the relationship between floor level and pressure difference in an existing technical solution B. Curve ③ is a diagram showing the relationship between floor level and pressure difference in a new technical solution A of the present invention. Curve ④ is a diagram showing the relationship between floor level and pressure difference in a new technical solution B of the present invention. Curve ⑤ is a diagram showing the relationship between floor level and pressure difference in a new technical solution C of the present invention. Detailed Implementation

[0074] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0075] Example 1: As Figure 1 The ventilation and exhaust system of a residential building shown includes: a vertical main exhaust pipe 2 and branch exhaust pipes 3, a main drain pipe 4 and branch drain pipes 5 respectively installed outside the kitchen or bathroom 1; one end of the branch exhaust pipe 3 is connected to the main exhaust pipe 2, and the other end of the branch exhaust pipe 3 is connected to each kitchen or bathroom 1 through a backflow preventer 3a and a smoke trap 10; the upper end of the main drain pipe 4 is connected to the upper end of the main exhaust pipe 2 through a connecting pipe 24; the upper end of the main exhaust pipe 2... The main drain pipe 4 is equipped with a hybrid exhaust device 6. The lower end of the main drain pipe 4 is equipped with a water seal valve 13. The outlet of the water seal valve 13's outlet bend 13c is connected to the sewage pipe network and septic tank. The top of the outlet bend 13c is higher than the height of the water seal valve 13's inlet 13e. One end of the branch drain pipe 5 is connected to the main drain pipe 4. The other end of the branch drain pipe 5 is connected to the floor drain 11 between the kitchen or bathroom 1. An air inlet 12 is provided between the kitchen or bathroom 1 and the outside.

[0076] After the exhaust device 6 is activated, the static pressure in the main exhaust pipe 2 and the main drain pipe 4 decreases. Stale gas from the kitchen or bathroom 1 enters the main exhaust pipe 2 and the main drain pipe 4 through the smoke trap 10, the fireproof check valve 3a, and the floor drain 11 (if the floor drain is not sealed properly). The stale gas is then discharged into the atmosphere by the suction of the exhaust device 6, or discharged into the gas purification device and then back into the atmosphere. During this process, fresh gas is continuously replenished into the kitchen or bathroom 1 through the air inlet 12. As long as the exhaust device 6 operates continuously and has sufficient exhaust volume, the pressure in the kitchen or bathroom 1 and other indoor spaces can be guaranteed to always be lower than the outdoor atmospheric pressure, or higher than the air pressure in the main exhaust pipe 2 and the main drain pipe 4, thus preventing cross-contamination of smoke, odors, backflow of smells, and smoke. When sewage and waste enter the main drain pipe 4 through the floor drain 11 or the toilet in the bathroom, the sewage and waste will fall into the water inlet valve 13 and flow into the sewage network. The water seal valve 13 prevents foul odors from the sewage network from flowing back into the main drain pipe 4. If the body 13a of the water seal valve 13 becomes blocked, the water seal valve maintenance cover 13b or the debris cleaning valve 13d can be opened for cleaning. The exhaust device 6 can also be an exhaust purification device that can both exhaust and purify foul gases.

[0077] Example 2: Figure 2 The ventilation and exhaust system of a residential building shown includes: a vertical main exhaust pipe 2 and branch exhaust pipe 3, a main drain pipe 4 and branch drain pipe 5 respectively installed outside the kitchen or bathroom 1; one end of the branch exhaust pipe 3 is connected to the main exhaust pipe 2, and the other end of the branch exhaust pipe 3 is connected to each kitchen or bathroom 1 through a check fire damper 3a and a smoke trap 10; the upper end of the main drain pipe 4 is equipped with a hybrid exhaust device 8; the lower end of the main exhaust pipe 2 is equipped with an electric exhaust device 7 and a protective net 7c; the lower end of the main drain pipe 4 is equipped with a water seal valve 13; the outlet of the water seal valve 13's water outlet bend 13c is connected to the sewage network and septic tank; the top height of the water outlet bend 13c is higher than the height of the inlet 13e of the siphon water seal 13; one end of the branch drain pipe 5 is connected to the main drain pipe 4; the other end of the branch drain pipe 5 is connected to the floor drain 11 between the kitchen or bathroom 1; and an air inlet 12 is provided between the kitchen or bathroom 1 and the outside. The air outlet of the protective net 7c or the air outlet of the exhaust fan 7 (the protective net 7c can also be removed at this time) is connected to the sewage pipe network through a connecting pipe 50.

[0078] After the exhaust devices 7 and 8 are activated, the static pressure in the main exhaust pipe 2 and the main drain pipe 4 decreases. The polluted gas from the kitchen or bathroom 1 enters the main exhaust pipe 2 and the main drain pipe 4 through the smoke collector 10, the fireproof check valve 3a, and the floor drain 11 (if the floor drain is not sealed properly). The polluted gas in the main drain pipe 4 is then discharged into the atmosphere by the suction of the exhaust device 8, or discharged into the gas purification device and then into the atmosphere. The polluted gas in the main exhaust pipe 2 enters the sewage network through the exhaust device 7 and the connecting pipe 50. During this process, fresh gas is continuously replenished into the kitchen or bathroom 1 through the air inlet 12. As long as the exhaust devices 7 and 8 operate continuously and have sufficient exhaust volume, the pressure in the kitchen or bathroom 1 and other indoor spaces can be guaranteed to always be lower than the outdoor atmospheric pressure, or higher than the air pressure in the main exhaust pipe 2 and the main drain pipe 4, thus preventing cross-contamination of smoke, odors, and backflow of smoke. When sewage and waste enter the main drain pipe 4 through the floor drain 11 or the toilet in the bathroom, the sewage and waste will fall into the water seal valve 13 and flow into the sewage network. The water seal valve 13 prevents the foul odor from the sewage network from flowing back into the main drain pipe 4. In case the body 13a of the water seal valve 13 is blocked, the water seal valve maintenance cover 13b or the debris cleaning valve 13d can be opened for cleaning. The exhaust devices 7 and 8 can also be exhaust purification devices that can both exhaust and purify foul gases.

[0079] Example 3: As Figure 3 The ventilation and exhaust system of the residential building shown differs from that of Embodiment 2 in that the upper port of the main exhaust pipe 2 and the upper port of the main drain pipe 4 are connected to the air inlet of the combined exhaust fan 68 via pipe 24, and the air outlet of the combined exhaust fan 68 is connected to the air purifier 69. Simultaneously, a foul gas check valve 13 is installed between the lower port of the main drain pipe 4 and the sewage network. A gas purifier 7b is installed on the air outlet of the exhaust fan 7 at the lower port of the main exhaust pipe 2. Part of the flue gas in the main exhaust pipe 2 is drawn in by the exhaust device 7 and purified by the air purifier 7b before being discharged into the atmosphere. The remaining part of the flue gas in the main exhaust pipe 2, along with the foul gas in the main drain pipe 4, is drawn in by the combined exhaust device 68 and purified by the air purifier 69 before being discharged into the atmosphere. The foul gas check valve 13 prevents foul gas from the main sewage network and septic tank from flowing back into the main drain pipe 4. The exhaust device 7 and the air purifier 7b can also be an integrated exhaust and purification device. The other contents are the same as those in Examples 1 and 2, and will not be repeated here.

[0080] Example 4: Figure 4The ventilation and exhaust system of the residential building shown differs from those in Embodiments 2 and 3 in that a hybrid exhaust device 6 is separately installed on the upper port of the main exhaust pipe 2. An upward connecting pipe 14e is connected between the lower port of the main drain pipe 4 and the inlet of the water seal valve 13. An automatic water-blocking exhaust valve 14 is connected to the outlet 14c of the connecting pipe 14e, and an exhaust device 9 is installed on the outlet of the automatic water-blocking exhaust valve 14. An exhaust check valve 7a is installed on the exhaust port of the exhaust device 7 at the lower port of the main exhaust pipe 2.

[0081] Under normal circumstances, the foul gas in the main drain pipe 4 will be discharged upward into the atmosphere along the main drain pipe 4 by the exhaust device 8; the foul gas in the lower part will be discharged downward into the atmosphere along the main drain pipe 4 by the exhaust device 9, and then through the connecting pipe 14e, the automatic water-blocking exhaust valve 14, and the exhaust device 9. In the event that the main body 13a of the water seal valve 13 is full of water or blocked, or the sewage pipe network is blocked, sewage may backflow into the connecting pipe 14e and enter the automatic water-blocking air vent valve 14 through the air inlet 14c. Because the weight of the valve plate 14b is greater than the exhaust suction of the exhaust fan 9 but less than the buoyancy of the float 14a, and the area of ​​the valve plate 14b is greater than the area of ​​the air outlet 14d but less than the area of ​​the inner cavity of the water-blocking air vent valve 14, the float 14a of the automatic water-blocking air vent valve 14 will float up and drive the valve plate 14b of the air vent valve 14 to close the exhaust outlet 14d, preventing sewage from overflowing through the electric exhaust device 9. Under normal conditions without backflow, the valve plate 14b and the float 14a will be in an open, ventilated state under their own weight. The air outlet of the one-way valve 7a and the air outlet of the exhaust device 9 can be connected to the sewage pipe network via a pipe (not shown in the figure). The other contents are the same as those in Examples 1, 2 and 3, and will not be repeated here.

[0082] Example 5: Figure 5 The ventilation and exhaust system of the residential building shown differs from that of Embodiment 4 in that the upper port of the main exhaust pipe 2 and the upper port of the main drain pipe 4 are sealed with sealing plates 6a and 8a, respectively; gas purifiers 7b and 9a are installed on the air outlets of exhaust devices 7 and 9, respectively. Stale air from the kitchens or bathrooms 1 on each floor enters the main exhaust pipe 2 and the main drain pipe 4 through branch exhaust pipes 3 and branch drain pipes 5, and flows downwards under the suction of exhaust devices 7 and 9, finally being purified by gas purifiers 7b and 9a before being discharged into the atmosphere. Exhaust devices 7 and 9 and air purifiers 7b and 9a can also be integrated exhaust purification devices, and their air outlets can be connected to the sewage network through a pipe (not shown in the figure). Other contents are the same as in Embodiments 2, 3, and 4, and will not be repeated here.

[0083] Example 6: As Figure 6The ventilation and exhaust system of the residential building shown differs from Embodiment 3 in that: a connecting pipe 14e is connected to the lower port of the pipe 16a between the lower port of the main drain pipe 4 and the check valve or water seal valve 13. An automatic water-proof exhaust valve or venting valve 14 is installed on the upper port of the connecting pipe 14e. The exhaust port of the automatic water-proof exhaust valve or venting valve 14 is then connected to the air inlet of the exhaust device 7 at the lower port of the main exhaust pipe 2 through another connecting pipe 16. The feature of this embodiment is that it enables simultaneous exhaust from both the upper and lower parts of the main exhaust pipe 2 and the main drain pipe 4, reducing the pressure difference unevenness between the upper and lower parts of the main exhaust pipe 2 and the main drain pipe 4, while also reducing the number of exhaust devices and gas purification devices and improving the operating efficiency of the equipment. The exhaust device 7 and the air purification device 7b can also be an integrated exhaust purification device, and its outlet can be connected to the sewage network through a pipe (not shown in the figure). The other contents are the same as those in Examples 1, 2, 3, 4 and 5, and will not be repeated here.

[0084] Furthermore, the upper ports of the main exhaust pipe 2 and the main drain pipe 4 in this technical solution can also be closed or connected through a connecting pipe, and the combined exhaust fan 68 and the combined purification device 69 can be removed to form a pure downdraft exhaust system using only one exhaust purification device. This technical solution is particularly suitable for mid- and low-rise residential buildings.

[0085] Example 7: Figure 7 The ventilation and exhaust system of the residential building shown differs from those in Embodiments 3 and 6 in that: Figure 7 The main exhaust duct 2 and main sewer 4 of multiple bathrooms or kitchens 1 are equipped with a combined exhaust purification device at their upper and lower ends. The exhaust purifier 7 can be connected to the sewage network through a pipe (not shown in the figure). Other contents are the same as in Embodiments 1, 2, 3, 4, 5, and 6, and will not be repeated here.

[0086] Example 8: As Figure 8The diagram shows a block diagram illustrating the control principle of an exhaust device for a residential building's ventilation system based on the wind speed within the exhaust pipe. The natural and electric hybrid exhaust device 15 includes: a natural exhaust cap 15a, an electric motor 15b, an impeller 15c, and a main exhaust pipe 2. It also includes a wind speed delay control switch 17, a wind speed sensor head 18, an infinite cycle timer switch 19, and a 220V AC power supply 20. The infinite cycle timer switch 19 is set to close and activate during cooking times (4-7 AM, 11-1 PM, and 4-6 PM), and deactivate and deactivate at other times. The wind speed delay control switch 17 is set to close and activate when the wind speed within the exhaust pipe is less than 3 m / s, deactivate and deactivate after a 5-minute delay when the wind speed is between 3 m / s and 3.5 m / s, and deactivate and deactivate when the wind speed is greater than 3.5 m / s. A key feature of this embodiment is that the electric exhaust device does not operate when cooking is not in use, saving electricity. When the electric exhaust device is not operating, exhaust is provided by the natural power exhaust device 15a.

[0087] Example 9: As Figure 9 The diagram illustrates a block diagram of an exhaust system for a residential building, based on the principle of controlling the pressure difference between the inside and outside of the exhaust pipe. The hybrid exhaust system 15 includes: a natural exhaust cap 15a, a motor 15b, an impeller 15c, and a main exhaust pipe 2. It also includes a micro-pressure difference control switch 24, a time-delay relay 23, a high-pressure sensor head 22, and a low-pressure sensor head 21. A 220V AC power supply 20 is provided. The micro-pressure difference control switch 24 is configured to disconnect the power supply and stop the system when the pressure difference between the outside and inside of the main exhaust pipe 2 is greater than 15Pa, and to close the power supply and start the system when the pressure difference is less than 15Pa. The time-delay relay 23 is set to have a delay time of not less than 5 minutes. A key feature of this embodiment is that the main exhaust pipe 2 is always kept under negative pressure, preventing backflow, cross-contamination, and odor generation.

[0088] Figure 10 This is a comparison chart of the pressure difference test curves between the interior 1 and the exhaust pipe 2 of an 18-story building using the technology of this invention and the technology of the prior art.

[0089] Figure 10 In the middle: Curve ①—×— represents the pressure difference test curves of each layer when the exhaust fan is running, with the exhaust fan installed at the upper port of the main exhaust pipe 2, the lower port of the main exhaust pipe 2 connected to the atmosphere, and the drain leak sealed.

[0090] Curve ②—v— represents the pressure difference test curves of each layer when the exhaust fan is running in the existing technical solution B: the exhaust fan is installed at the upper port of the main exhaust pipe 2, the upper port of the main drain pipe is open, the lower port of the main exhaust pipe is closed, the drain leak is closed.

[0091] Curve ③—o— represents a new technical solution A of the present invention: an exhaust fan is installed on the lower port of the main exhaust pipe 2, the upper port is closed, the lower water leak is closed, and the pressure difference test curve of each layer is obtained when the exhaust fan is running.

[0092] Curve ④—*— represents a new technical solution B of this invention: an exhaust fan is installed on the lower port of the main exhaust pipe 2, the upper port is connected to the atmosphere, the lower water leak is sealed, and the pressure difference test curve of each layer is shown when the exhaust fan is running.

[0093] Curve ⑤—·— represents a new technical solution C of this invention: Exhaust fans are installed on both the lower and upper ports of the main exhaust pipe 2, and the sum of the power of the two exhaust fans equals the power of one exhaust fan as shown in the curve above. The drain is sealed, and the pressure difference test curves for each layer are shown during exhaust fan operation.

[0094] from Figure 10 The following conclusions can be drawn from the comparison of various test curves: (1) Comparing curve ① with curve ② or curve ③ with curve ④, when an exhaust fan is installed at one port of exhaust pipe 2 and the other port is closed, the pressure difference between indoor 1 and exhaust pipe 2 will be greater than that between indoor 1 and exhaust pipe 2 when the other port is open (connected to the atmosphere). That is, when one port of the main exhaust pipe 2 is closed, the exhaust speed or exhaust volume will be greater. (2) Comparing curve ③ with curve ②, when an exhaust fan is installed at the lower port of the main exhaust pipe 2, the pressure difference between indoor 1 and exhaust pipe 2 will be slightly higher than that between indoor 1 and exhaust pipe 2 when an exhaust fan is installed at the upper port. (3) Comparing curves ①, ②, ③, ④ with curve ⑤, when exhaust fans are installed at both the upper and lower ports of exhaust pipe 2 (the sum of the power of the two exhaust fans is equal to the power of the exhaust fan installed at one port), the pressure difference between indoor 1 and exhaust pipe 2 will be higher than that when an exhaust fan is installed at one exhaust port. Moreover, the pressure difference between each floor in exhaust pipe 2 is relatively more uniform. Pressure difference non-uniformity = (highest pressure difference - lowest pressure difference) / number of floors. The pressure differential non-uniformity of curve ⑤ is (135Pa-80Pa) / 18 layers = 3Pa / layer. The pressure differential non-uniformity of curve ③ is (115Pa-35Pa) / 18 layers = 4.4Pa / layer.

[0095] The values ​​and patterns of change after various other state changes are basically the same as those in the above conclusions, and will not be repeated here.

[0096] Although a ventilation and exhaust system for a residential building has been described in conjunction with preferred embodiments, the invention is not limited to the specific forms described herein. Rather, it is intended to cover various alternatives, modifications, new combinations and equivalents derived from recombination of various feature elements that would naturally fall within the scope of the invention as defined by the claims.

Claims

1. A ventilation and exhaust system for a residential building, comprising: Main exhaust pipes and branch exhaust pipes, as well as main drain pipes and branch drain pipes, are respectively installed in or outside the kitchens and bathrooms on each floor of the residential building. The main exhaust pipes and main drain pipes each have upper and lower ends. Each branch exhaust pipe has two ports, one connected to the main exhaust pipe and the other connected to the interior or equipped with a smoke trap, exhaust device, or airflow regulating valve or a combination thereof, and connected to the interior. Alternatively, the branch exhaust pipe may be equipped with a fireproof check valve, check valve, fire damper, or airflow regulating valve or a combination thereof. The lower end of the main drain pipe connects to the sewage network and septic tank. Each branch drain pipe has two ports, one connected to the main drain pipe and the other connected to the space of the kitchen or bathroom or to the outlet of a backflow preventer. The inlet of the reverse device is connected to the space of the kitchen and bathroom; each floor's kitchen and bathroom is provided with an air inlet between itself and the outside or between itself and the outside through the indoor space. The air inlet is connected to the atmosphere or is equipped with an air purifier, a volume regulating valve, an air intake fan, or a fresh air device with a heat exchanger or a combination thereof. The feature is that an exhaust device or an exhaust purification device is connected to the upper end of the main exhaust pipe and the upper end of the main drain pipe of the kitchen and bathroom. The exhaust device or exhaust purification device is provided with an air inlet and an exhaust outlet. The upper end of the main exhaust pipe and the upper end of the main drain pipe of the kitchen and bathroom are connected to the air inlet of the exhaust device or exhaust purification device. The exhaust outlet is connected to the outdoor atmosphere. At the same time, a check valve or a water seal valve is connected between the lower end of the main drain pipe and the sewage network through a pipeline.

2. The ventilation and exhaust system for a residential building according to claim 1, characterized in that: A vent is provided at the lower end of the main exhaust pipe in the kitchen and bathroom. The vent is connected to an exhaust device or an exhaust purification device via a connecting pipe. One end of the connecting pipe is connected to the vent at the lower end of the main exhaust pipe, and the other end is connected to the air inlet of the exhaust device or exhaust purification device.

3. The ventilation and exhaust system for a residential building according to claim 2, characterized in that: A connecting pipe is connected upwards to the lower port of the main drain pipe between the lower end of the main drain pipe and the check valve or water seal valve. An air vent valve or automatic water-blocking air vent valve is installed on the upper port of the connecting pipe. The air vent valve or automatic water-blocking air vent valve is provided with an air inlet and an air outlet. The air inlet is connected to the upper port of the connecting pipe.

4. A ventilation and exhaust system for a residential building according to claim 3, characterized in that: The exhaust port of the exhaust valve or automatic water-proof exhaust valve is connected to the air inlet of the exhaust device or exhaust purification device at the lower end of the main exhaust pipe through a pipeline. The exhaust port of the exhaust device or exhaust purification device at the lower end of the main exhaust pipe is connected to the atmosphere or to the sewage network through a pipeline.

5. A ventilation and exhaust system for a residential building according to claim 3, characterized in that: An exhaust device or exhaust purification device is installed on the exhaust port of the exhaust valve or automatic water-proof exhaust valve.

6. A ventilation and exhaust system for a residential building according to claim 1, 2, 3, 4, or 5, characterized in that: An exhaust device or exhaust purification device is installed via a pipeline near the pressure neutral surface at the midpoint of the vertical height of the main exhaust pipe.

7. A ventilation and exhaust system for a residential building, comprising: Main exhaust pipes and branch exhaust pipes, as well as main drain pipes and branch drain pipes, are respectively installed in or outside the kitchens and bathrooms on each floor of the residential building. The main exhaust pipes and main drain pipes each have upper and lower ends. Each branch exhaust pipe has two ports, one connected to the main exhaust pipe and the other connected to the interior or equipped with a smoke trap, exhaust device, or airflow regulating valve or a combination thereof, and connected to the interior. Alternatively, the branch exhaust pipe may be equipped with a fireproof check valve, check valve, fire damper, or airflow regulating valve or a combination thereof. The lower end of the main drain pipe connects to the sewage network and septic tank. Each branch drain pipe has two ports, one connected to the main drain pipe and the other connected to the space of the kitchen or bathroom or to the outlet of a backflow preventer. The inlet of the reverse device is connected to the space of the kitchen and bathroom; each floor's kitchen and bathroom is provided with an air inlet between itself and the outside or between the indoor space and the outside, and the air inlet is connected to the atmosphere or is equipped with an air purifier, air volume regulating valve, air intake fan, or fresh air device with heat exchanger or a combination thereof. The feature is that: the upper end of the main exhaust pipe of the kitchen and bathroom is closed, and a vent is opened at the lower end of the main exhaust pipe of the kitchen and bathroom. An exhaust device or exhaust purification device is connected to the vent through a pipe. The exhaust device or exhaust purification device is provided with an air inlet and an exhaust outlet. The vent is connected to the air inlet of the exhaust device or exhaust purification device through a pipe. A check valve or water seal valve is connected between the lower end of the main drain pipe and the sewage network through a pipe.

8. A ventilation and exhaust system for a residential building according to claim 7, characterized in that: A lower port of a connecting pipe is connected upwards on the pipeline between the lower end of the main drain pipe and the check valve or water seal valve. An air vent valve or an automatic water-blocking air vent valve is installed on the upper port of the connecting pipe. The air vent valve or the automatic water-blocking air vent valve is provided with an air inlet and an air outlet. The air inlet of the air vent valve or the automatic water-blocking air vent valve is connected to the upper port of the connecting pipe.

9. A ventilation and exhaust system for a residential building according to claim 8, characterized in that: The upper end of the main drain pipe is sealed, and the exhaust port of the exhaust valve or automatic water-blocking exhaust valve is connected to the air inlet of the exhaust device or exhaust purification device at the lower end of the main exhaust pipe through a pipeline. The exhaust port of the exhaust device or exhaust purification device is connected to the atmosphere or to the sewage network through a pipeline.

10. A ventilation and exhaust system for a residential building according to claim 8, characterized in that: The upper end of the main drain pipe is sealed, and an exhaust device or exhaust purification device is installed on the exhaust port of the exhaust valve or automatic water-blocking exhaust valve.

11. A ventilation and exhaust system for a residential building according to claim 7, 8, 9, or 10, characterized in that: An exhaust device or exhaust purification device is installed via a pipeline near the pressure neutral surface at the midpoint of the vertical height of the main exhaust pipe.

12. A ventilation and exhaust system for a residential building according to claim 7, 8, 9, or 10, characterized in that: A vent is provided on the side of the upper end of the main exhaust pipe in the kitchen or bathroom. An exhaust device or an exhaust purification device is installed through the vent on the side of the upper end of the main exhaust pipe in the kitchen or bathroom.

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