Device for reducing indoor carbon dioxide concentration
By designing a carbon dioxide absorption device that utilizes alkali metal carbonate solution and inert solid powder, an efficient reduction of indoor carbon dioxide concentration is achieved, poor ventilation and high solid waste and cost problems of the alkali lime method are solved, and recycling and low-cost purification effects are achieved.
Patent Information
- Application Number
- CN202510312571.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-17
- Publication Date
- 2025-06-06
AI Technical Summary
The prior art has problems of oxygen loss caused by poor ventilation when reducing indoor carbon dioxide concentration, and the commonly used soda lime method has problems of solid waste disposal and high cost.
Design a device to use alkali metal carbonate solution and inert solid powder (such as activated carbon powder, alumina powder, silicon oxide powder) as carbon dioxide absorption liquid, and achieve efficient removal of carbon dioxide through absorption/desorption cycle, and realize recycling by heating and regenerating the absorption liquid.
The device can efficiently reduce the indoor carbon dioxide concentration, avoid oxygen loss caused by ventilation, and reduce solid waste and operating costs through circulation and regeneration.
Smart Images
Figure CN120101258A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of air purification, relates to a carbon dioxide reduction technology, and specifically relates to a device for reducing indoor carbon dioxide concentration. Background Art
[0002] Human respiration is an important physiological process for the body to maintain life activities. Its essence is to oxidize and decompose organic matter such as glucose and release energy for the body to use. In this process, carbon dioxide is produced as a metabolite and is excreted from the body through the respiratory system. Generally speaking, an average adult breathes about 12-16 times per minute, inhales about 0.5 liters of oxygen and exhales about 0.25 liters of carbon dioxide per minute. In addition, exercise, cold weather and other conditions will significantly increase the frequency and depth of breathing, leading to increased carbon dioxide emissions.
[0003] Studies have shown that when the concentration of carbon dioxide in the air reaches 0.1% (1000PPM), people will feel dull, palpitations, lack of concentration, slower reaction time, memory loss, and work efficiency will also decrease. This is because high concentrations of carbon dioxide affect the oxygen supply to the brain, thereby affecting brain function. Long-term exposure to high concentrations of carbon dioxide will increase the risk of respiratory diseases such as asthma and chronic obstructive pulmonary disease. When the concentration of carbon dioxide in the air reaches 1500~2000PPM, people will feel shortness of breath, dizziness, vertigo, lack of concentration, and mental fatigue. This is because carbon dioxide affects the acid-base balance in the blood, thereby affecting the normal function of the brain. Increased indoor carbon dioxide concentrations can affect sleep quality, resulting in reduced sleep time and decreased sleep quality. This is because high concentrations of carbon dioxide affect the human body's breathing rhythm, thereby affecting sleep. When the concentration of carbon dioxide in the air reaches more than 5000PPM, the human body's functions are seriously confused, causing people to lose consciousness and become unconscious, which may lead to severe hypoxia, permanent brain damage, coma, or even death.
[0004] Poor ventilation is the main reason for the increase of indoor carbon dioxide concentration. When the indoor air circulation is poor, the carbon dioxide produced by people's breathing will accumulate indoors, causing the concentration to increase. Crowded places, such as classrooms and offices, are more likely to have the problem of increased carbon dioxide concentration. Because the more people there are, the more carbon dioxide is produced by breathing. Opening windows regularly or using air conditioning to keep the indoor air circulating is an effective way to reduce the indoor carbon dioxide concentration.
[0005] However, in certain indoor environments, ventilation is not the best choice for reducing carbon dioxide concentrations. For example, the carbon dioxide concentration in a hyperbaric oxygen chamber will gradually rise after people enter, and ventilation will cause a large loss of oxygen in the chamber, causing economic losses and reducing feasibility. In addition, indoor areas in plateaus usually use oxygen to compensate for plateau hypoxia. If ventilation is used to reduce carbon dioxide concentrations, it will also cause a large loss of indoor oxygen. Currently, the most commonly used method for removing indoor carbon dioxide is chemical absorption using soda lime. This method is highly efficient, but the soda lime needs to be replaced regularly, and there are problems with solid waste disposal and high costs. Therefore, there is an urgent need to develop a device that can recycle and effectively reduce indoor carbon dioxide concentrations. Summary of the invention
[0006] In order to overcome the above-mentioned deficiencies of the prior art, the technical solution adopted by the present invention is a device for reducing the indoor carbon dioxide concentration, which can absorb carbon dioxide in the indoor air and regenerate the absorption liquid by heating after absorption saturation, thereby realizing an absorption / desorption cycle.
[0007] In order to achieve the above object, the technical solution adopted by the present invention is: A device for reducing indoor carbon dioxide concentration comprises an air intake system, an absorption / desorption system, and a water return / water replenishment system, characterized in that an air compressor or a high-pressure fan (11) is connected to an aeration head (5) in an absorption tank (8) through a solenoid valve (14) to form an air intake system, an agitator (4) is provided in the absorption tank (8) and filled with carbon dioxide absorption liquid to form an absorption / desorption system; the absorption tank (8) is connected to the upper and lower ends of a water storage tank (9) in two ways, one way is provided with an air-cooled fin radiator (3), and the other way is provided with a water replenishment pump (10); the water pipe of the water storage tank (9) is connected to a water vapor separator (2) through a solenoid valve (13), the air pipe is connected to the water vapor separator (2), and the air pipe of the water vapor separator (2) is connected to an electric four-way valve (12) to form a water return / water replenishment system.
[0008] The air intake system, the absorption / desorption system, and the water return / water replenishment system are connected through air pipes and water pipes, and are switched on and off by an electric four-way valve (12), a solenoid valve (13), and a solenoid valve (14).
[0009] The water storage tank (9) is provided with a heater and a temperature sensor (7).
[0010] The air intake system, absorption / desorption system, and water return / water replenishment system are provided in two groups, wherein the air compressor or high-pressure fan (11) is respectively connected to the two groups of absorption tanks (8), the two groups of water storage tanks (9) are connected by a solenoid valve (13), and a solenoid valve (13) is provided to connect the ground leakage, and the two groups of water vapor separators are connected by an electric four-way valve (12).
[0011] The absorption tank (8) and the water storage tank (9) are both provided with a liquid level meter (6).
[0012] The system consisting of the air intake system, the absorption / desorption system, and the water return / water replenishment system is provided with temperature, humidity, and carbon dioxide concentration sensors (1).
[0013] The temperature sensors, liquid level sensors, humidity sensors, carbon dioxide concentration sensors and solenoid valves in the air intake system, absorption / desorption system and return / make-up water system automatically adjust the absorption tank temperature and intake air flow rate according to the ambient air temperature, humidity and carbon dioxide concentration at the purified gas outlet through the control system, and automatically adjust to the set height according to the change of the liquid level height in the absorption / desorption tank and the water storage tank, and electrically control the electrical components of the device such as the air compressor or high-pressure fan, heater, agitator, fan, water pump, solenoid valve, etc.
[0014] The carbon dioxide absorbing liquid is prepared by mixing one or more of activated carbon powder, aluminum oxide powder and silicon oxide powder with carbonate solution.
[0015] The carbonate solution is Li 2 CO 3 , Na 2 CO 3 , K 2 CO 3 A mixed solution of one or more of these with water.
[0016] The mass content of the carbonate in the solution is 20-65%.
[0017] The mass content of the activated carbon powder, aluminum oxide powder and silicon oxide powder in the absorption liquid is 0.1-5%.
[0018] The principle and effect of this patent: Alkali metal carbonates can absorb a large amount of carbon dioxide to generate bicarbonate, and the corresponding bicarbonate can decompose and release carbon dioxide when heated to regenerate the absorption liquid; by adding inert solid powders, such as activated carbon powder, aluminum oxide powder, silicon oxide powder, etc., the gas-liquid-solid interface is increased, and the carbon dioxide absorption rate and removal efficiency are improved; by monitoring the environment and the outlet temperature, humidity, and carbon dioxide concentration of the purified air, the absorption liquid temperature and the inlet gas flow rate are controlled in real time, and by monitoring the liquid level height of the absorption / desorption and water storage tanks, the absorption / desorption and water storage tanks are controlled in real time, thereby achieving the control of the purified gas outlet temperature, humidity, and carbon dioxide concentration and solving the problem of the absorption liquid being diluted by water in the air when the ambient humidity is high and the absorption liquid water evaporation loss when the ambient humidity is low. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1A flow diagram of a device for reducing carbon dioxide concentration indoors. 1 is a temperature, humidity, and carbon dioxide concentration sensor, 2 is a water vapor separator, 3 is an air-cooled finned radiator, 4 is a stirrer, 5 is an aeration head, 6 is a liquid level gauge, 7 is a heater and a temperature sensor, 8 is an absorption tank, 9 is a water storage tank, 10 is a water supply pump, 11 is an air compressor or a high-pressure fan, 12 is an electric four-way valve, 13 is a solenoid valve, and 14 is a solenoid valve. DETAILED DESCRIPTION
[0020] The present invention is further described below in conjunction with the accompanying drawings and embodiments, but the present invention is not limited to the following embodiments. Example 1
[0021] Two 100L tanks were filled with 50L of 20% Na 2 CO 3 Solution, 2.75 kg commercially available alumina powder. Ambient temperature 25 o C, humidity 60%, when the carbon dioxide concentration exceeds 800ppm, turn on the high-pressure fan (the user can set the carbon dioxide concentration threshold for turning on the device according to needs), air flow rate 2m 3 / min, enters 1# tank. Purified gas outlet air temperature 25 o C, humidity 60%, carbon dioxide concentration 78ppm. After running for 8 hours, the temperature of tank 1# is raised to 98 o C, and continuously introduce air at 0.1m 3 / min, regenerate the absorption liquid. o After 30 minutes of heat preservation at 400 °C, the regeneration is completed and the tank is cooled naturally. At the same time, the 2# tank absorbs carbon dioxide and starts the next cycle. About 3450L of carbon dioxide, or about 6.81kg, is absorbed in 24 hours, which can maintain the carbon dioxide concentration in the space where 9 people are located at no more than 800ppm. Example 2
[0022] Two 100L tanks were filled with 50L of 50% K 2 CO 3 Solution, 0.1 kg commercial activated carbon powder and 0.5 kg commercial silicon oxide powder. Ambient temperature 25 o C, humidity 60%, when the carbon dioxide concentration exceeds 800ppm, turn on the high-pressure fan, the air flow rate is 4m 3 / min, ambient temperature 35 o C, humidity 80%, enters 1# tank. Purified gas outlet air temperature 35 o C, humidity 50%, carbon dioxide concentration 132ppm. After running for 8 hours, the temperature of tank 1# is raised to 105 o C, and continuously introduce air at 0.1m 3 / min, regenerate the absorption liquid. o C for 120 minutes, and about 22L of water absorbed from the air during this period is evaporated and stored in the water tank. When the regeneration is completed, it is cooled naturally. When the water tank reaches about 70% of the volume, it is automatically discharged to about 30% of the volume. At the same time, the 2# tank absorbs carbon dioxide and starts the next cycle. About 3850L of carbon dioxide, or about 7.60kg, is absorbed in 24 hours, which can maintain the carbon dioxide concentration in the space where 10 people are located at no more than 800ppm. Example 3
[0023] Two 100L tanks were filled with 50L of 20% Li 2 CO 3 and Na 2 CO 3 The mixed solution of the two carbonates was prepared in a mass ratio of 1:1 and 1.75 kg of commercially available silicon oxide powder. o C, humidity 30%, carbon dioxide concentration 800ppm, air compressor on, air flow rate 3.5 m 3 / min, enters 1# tank. Purified gas outlet air temperature 25 o C, humidity 40%, carbon dioxide concentration 88ppm. After running for 12 hours, raise the temperature of tank 1 to 95 o C, and continuously introduce air at 0.1m 3 / min, regenerate the absorption liquid. o C for 10 minutes, during which time tank 1# evaporates about 6L of water into the air. A water pump is used to extract 6L of water from the water storage tank and add it to tank 1#, and the regeneration is completed and cooled naturally. When the water in the water storage tank is less than about 30% of the volume, the valve connected to the tap water pipe is opened to add water to the water storage tank to 70% of the volume. Water can also be added to the water storage tank manually. At the same time, tank 2# absorbs carbon dioxide and starts the next cycle. About 3600L of carbon dioxide, or about 7.00kg, is absorbed in 24 hours, which can maintain the carbon dioxide concentration in the space where 10 people are located at no more than 800ppm. Example 4
[0024] Two 100L tanks were filled with 50L of 65% K 2 CO 3 Solution, 0.075 kg commercial activated carbon powder. Ambient temperature 10 o C, humidity 80%, carbon dioxide concentration 1000ppm, air compressor on, air flow rate 5m 3 / min, enters 1# tank. Purified gas outlet air temperature 10 o C, humidity 50%, carbon dioxide concentration 76ppm. After running for 12 hours, the temperature of tank 1# is raised to 105 oC, and continuously introduce air at 0.1m 3 / min, regenerate the absorption liquid. o C for 70 minutes, and evaporate about 10L of water absorbed from the air during this period and store it in the water tank. When the regeneration is over, it will cool naturally. When the water tank reaches about 70% of the volume, it will automatically discharge to about 30% of the volume. At the same time, the 2# tank absorbs carbon dioxide. It absorbs about 6660L of carbon dioxide in 24 hours, or about 13.0kg, which can maintain the carbon dioxide concentration in the space where 18 people are located at no more than 1000ppm. Example 5
[0025] Two 30L tanks were filled with 15L of 20% Na 2 CO 3 Solution, 1.3 kg commercial aluminum oxide powder and 0.7 kg commercial silicon oxide powder. Turn on the high-pressure blower with an air flow rate of 1.5 m 3 / min, ambient temperature 35 o C, humidity 30%, carbon dioxide concentration 800ppm, enters 1# tank. Purified gas outlet air temperature 35 o C, humidity 50%, carbon dioxide concentration 80ppm. After running for 3 hours, raise the temperature of tank 1 to 98 o C, and continuously introduce air at 0.03m 3 / min, regenerate the absorption liquid. o C for 10 minutes, during which time tank 1# evaporates about 2.4L of water into the air. A water pump is used to extract 2.4L of water from the water storage tank and add it to tank 1#. The regeneration is completed and the tank is cooled naturally. When the water in the water storage tank is less than about 30% of the volume, the valve connected to the tap water pipe is opened to add water to the water storage tank to 70% of the volume. Water can also be added to the water storage tank manually. At the same time, tank 2# absorbs carbon dioxide and starts the next cycle. About 1550L of carbon dioxide, or about 3.05kg, is absorbed in 24 hours, which can maintain the carbon dioxide concentration in the space where 4 people are located at no more than 800ppm.
[0026] Comparative Example 1 Two 30L tanks were filled with 15L of 20% Na 2 CO 3 Solution, no solid powder added. Turn on the high pressure blower, air flow rate 1.5m 3 / min, ambient temperature 35 o C, humidity 30%, carbon dioxide concentration 800ppm, enters 1# tank. Purified gas outlet air temperature 35 o C, humidity 50%, carbon dioxide concentration 425ppm. After running for 3 hours, raise the temperature of tank 1# to 98 o C, and continuously introduce air at 0.03m3 / min, regenerate the absorption liquid. o C for 10 minutes, during which time tank 1# evaporates about 2.4L of water into the air. A water pump is used to extract 2.4L of water from the water storage tank and add it to tank 1#, and the regeneration is completed and cooled naturally. When the water in the water storage tank is less than about 30% of the volume, the valve connected to the tap water pipe is opened to add water to the water storage tank to 70% of the volume. Water can also be added to the water storage tank manually. At the same time, tank 2# absorbs carbon dioxide and starts the next cycle. About 810L of carbon dioxide, or about 1.60kg, is absorbed in 24 hours, which can only maintain the carbon dioxide concentration in the space where 2 people are located at no more than 800ppm.
Claims
1. A device for reducing indoor carbon dioxide concentration, comprising an air intake system, an absorption / desorption system, and a water return / water replenishment system, characterized in that: An air compressor or a high-pressure fan (11) is connected to an aeration head (5) in an absorption tank (8) through a solenoid valve (14) to form an air intake system. An agitator (4) is provided in the absorption tank (8) and filled with carbon dioxide absorption liquid to form an absorption / desorption system. The absorption tank (8) is connected to the upper and lower ends of a water storage tank (9) in two ways, one way is provided with an air-cooled fin radiator (3), and the other way is provided with a water supply pump (10). The water pipe of the water storage tank (9) is connected to a water vapor separator (2) through a solenoid valve (13), and an air pipe is connected to the water vapor separator (2). The air pipe of the water vapor separator (2) is connected to an electric four-way valve (12) to form a water return / water supply system.
2. A device for reducing indoor carbon dioxide concentration according to claim 1, characterized in that: The air intake system, the absorption / desorption system, and the water return / water replenishment system are connected through air pipes and water pipes, and are switched on and off by an electric four-way valve (12), a solenoid valve (13), and a solenoid valve (14).
3. The device for reducing indoor carbon dioxide concentration according to claim 1, characterized in that: The water storage tank (9) is provided with a heater and a temperature sensor (7).
4. The device for reducing indoor carbon dioxide concentration according to claim 1, characterized in that: The air intake system, absorption / desorption system, and water return / water replenishment system are provided in two groups, wherein the air compressor or high-pressure fan (11) is respectively connected to the two groups of absorption tanks (8), the two groups of water storage tanks (9) are connected by a solenoid valve (13), and a solenoid valve (13) is provided to connect the ground leakage, and the two groups of water vapor separators are connected by an electric four-way valve (12).
5. The device for reducing indoor carbon dioxide concentration according to claim 1, characterized in that: The absorption tank (8) and the water storage tank (9) are both provided with a liquid level meter (6).
6. The device for reducing indoor carbon dioxide concentration according to claim 1, characterized in that: The system consisting of the air intake system, the absorption / desorption system, and the water return / water replenishment system is provided with temperature, humidity, and carbon dioxide concentration sensors (1).
7. The device for reducing indoor carbon dioxide concentration according to claim 1, characterized in that: The temperature sensors, liquid level sensors, humidity sensors, carbon dioxide concentration sensors and solenoid valves in the air intake system, absorption / desorption system and return / make-up water system automatically adjust the absorption tank temperature and intake air flow rate according to the ambient air temperature, humidity and carbon dioxide concentration at the purified gas outlet through the control system, and automatically adjust to the set height according to the change of the liquid level height in the absorption / desorption tank and the water storage tank, and electrically control the electrical components of the device such as the air compressor or high-pressure fan, heater, agitator, fan, water pump, solenoid valve, etc.
8. The device for reducing indoor carbon dioxide concentration according to claim 1, characterized in that: The carbon dioxide absorbing liquid is prepared by mixing one or more of activated carbon powder, aluminum oxide powder and silicon oxide powder with carbonate solution.
9. The device for reducing indoor carbon dioxide concentration according to claim 1, characterized in that: The carbonate solution is a mixed solution of one or more of Li2CO3, Na2CO3, K2CO3 and water.
10. The device for reducing indoor carbon dioxide concentration according to claim 1, characterized in that: The mass content of the carbonate in the solution is 20-65%, and the mass content of the activated carbon powder, aluminum oxide powder and silicon oxide powder in the absorption liquid is 0.1-5%.