A drought control system based on diverting moist airflow at low altitudes

Abstract

This invention relates to a drought control system based on the transfer of humid airflow from low altitudes. The system includes a ventilation duct built along a mountainside, located in the windward area of ​​one side of the mountain. The outlet of the ventilation duct is at an altitude H2 higher than the inlet, extending to near the ridgeline of the mountain. Humid airflow from low altitudes enters the ventilation duct through the inlet, is guided by the duct, and is discharged through the outlet, ultimately crossing the ridgeline to reach the arid area on the other side of the mountain. This drought control system has a simple and reasonable structure, low technical content, reliable performance, low cost, and is easy to maintain.

Description

Technical Field

[0001] This invention relates to the technical field of drought control, specifically a drought control system based on diverting humid air currents from low altitudes. Background Technology

[0002] The climate characteristics of arid regions are sparse rainfall and high evaporation. Natural geographical causes: Location relative to land and sea: Arid regions are located in the heart of the Eurasian continent, far from water sources such as the Pacific and Indian Oceans, making it difficult for summer monsoons to penetrate, thus hindering water vapor transport.

[0003] Topographical barriers: Surrounded by high mountain ranges such as the Kunlun Mountains, Tianshan Mountains, Qinling Mountains, and Greater Khingan Mountains, the basin and plateau are further blocked from receiving moist air currents from the ocean. More importantly, when moist air currents cross the mountains, they rise slowly and over a long period on the windward slopes. As the temperature decreases with altitude, most of the moisture in the air currents condenses and is lost as rainfall before crossing the ridgeline. Therefore, the air that manages to cross the ridgeline becomes sparse and dry, which is one of the main reasons why arid regions are dry.

[0004] Climate and circulation characteristics: Rainfall is scarce: It has a typical temperate continental climate with an annual precipitation of less than 200 mm, and in some areas (such as the Turpan Basin), the annual precipitation is even less than 10 mm.

[0005] High evaporation: Due to low rainfall, many sunny days, and high summer temperatures, surface evaporation far exceeds rainfall, exacerbating the drought.

[0006] Atmospheric circulation: The area is long dominated by continental air masses, with prevailing high-pressure systems and weak cold air activity, which is unfavorable for cloud formation and rainfall. Furthermore, although some arid regions have shown a trend of "warming and humidification" in recent years, with fluctuating increases in precipitation, the fundamental climate pattern of long-term drought has not changed, and global warming may lead to more frequent extreme weather events. Human activities such as excessive exploitation of water resources are also exacerbating water shortages in some areas.

[0007] To address drought issues in arid regions, the current approach mainly combines emergency response with routine drought relief measures, including water resource allocation, artificial rain enhancement, water-saving irrigation, and technological support. However, these measures involve enormous investments in manpower, energy, funding, and technology, present significant challenges, and require overcoming numerous obstacles. Furthermore, subsequent maintenance is quite troublesome and costly. Therefore, it is necessary to design a drought management system that can overcome the existing problems. Summary of the Invention

[0008] The purpose of this invention is to overcome the shortcomings of the existing technology and provide a drought control system based on the transfer of humid airflow at low altitudes, which is simple and reasonable in structure, low in technical content, reliable in performance, low in cost, and easy to maintain.

[0009] The objective of this invention is achieved as follows: A drought control system based on the transfer of low-altitude humid airflow includes a ventilation duct built along the mountainside, located in the windward area on one side of the mountain. The altitude H2 of the ventilation duct's outlet is higher than the altitude H1 of its inlet, and the outlet extends to the vicinity of the mountain's ridgeline. Low-altitude humid airflow enters the ventilation duct through the inlet, is guided by the ventilation duct, and is discharged through the outlet, eventually crossing the ridgeline to reach the arid area on the other side of the mountain.

[0010] As a specific solution, the ventilation area within the ventilation duct gradually increases or decreases from the air inlet to the air outlet; or, the ventilation area at different locations within the ventilation duct remains consistent.

[0011] As another specific solution, the air inlet is equipped with a funnel-shaped air-gathering and rectifying structure, with the larger end of the air-gathering and rectifying structure facing outward to collect humid airflow over a wide area and reduce turbulence resistance.

[0012] As another specific solution, the air outlet of the ventilation duct should be close to, reach or cross the ridgeline, so that the humid airflow ejected from the air outlet can cross the ridgeline.

[0013] As another specific solution, this drought control system also includes a monitoring terminal for monitoring the ventilation duct and a detection device group installed on the ventilation duct; the detection device group includes a pressure detection device for detecting the internal pressure of the ventilation duct and / or a temperature detection device for detecting the internal temperature of the ventilation duct and / or a humidity detection device for detecting the internal humidity of the ventilation duct and / or a wind speed detection device for detecting the wind speed of the humid airflow in the ventilation duct, and the pressure detection device and / or temperature detection device and / or humidity detection device and / or wind speed detection device are communicatively connected to the monitoring terminal.

[0014] As another specific solution, two or more detection devices of the same type are set along the extension direction of the ventilation duct, with at least one detection device set at the air inlet and at least one detection device set at the air outlet.

[0015] As another specific solution, a fan is installed inside the ventilation duct to assist the flow of humid air towards the air outlet. The fan is matched with the cross-section of the ventilation duct and is connected to the power grid.

[0016] As another specific solution, the air inlet and / or air outlet are provided with a protective structure to prevent foreign objects from entering the ventilation duct, and the protective structure has ventilation characteristics; and / or, the air inlet and / or air outlet are provided with a duct valve for opening or closing the location.

[0017] As another specific solution, the outer wall of the ventilation duct is made of one or more of the following materials: stainless steel, aluminum alloy, plastic, rubber, and reinforced concrete, while the inner wall of the ventilation duct is smooth.

[0018] As another specific option, the altitude H1 of the air intake end is below or above 1000 meters, including 1000 meters.

[0019] As another specific option, one or more ventilation ducts are distributed along the ridgeline; or, ventilation ducts are set up in the valley between two mountains.

[0020] The beneficial effects of this invention are as follows: On the windward side of the mountain, a ventilation duct is built along the mountainside. There is an elevation difference between the air outlet and the air inlet of the ventilation duct. Utilizing the suction principle of the chimney effect (also known as the hot pressure effect), the humid air that slowly rises from the low elevation of the windward area is drawn into the ventilation duct. The humid air is rapidly elevated within the ventilation duct to the top of the mountain. It is then ejected from the air outlet of the ventilation duct and crosses the ridgeline to reach the arid area on the other side of the mountain. The humid air then condenses and forms rain, becoming a water source to combat drought. In this system, the ventilation ducts operate without relying on other machinery or consuming electricity, fuel, or other energy. They utilize the smokestack effect to transfer humid air from the windward area to the arid area, thereby providing the arid region with ample water for irrigation, factory and mine use, and other purposes. This system carries no other potential risks. Furthermore, its simple structure, practicality, durability, and low-cost one-time investment make it easy to manage with minimal manpower requirements and simple, low-cost maintenance. Additionally, the multiple ventilation ducts built into the mountainside create a magnificent landscape and can even become a tourist attraction, increasing revenue. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the drought control system in the first embodiment of the present invention.

[0022] Figure 2 This is a schematic diagram of the drought control system in the first embodiment of the present invention.

[0023] Figure 3 This is a distribution diagram of multiple ventilation ducts in the first embodiment of the present invention.

[0024] Figure 4 This is a schematic diagram of the installation of the ventilation duct in the first embodiment of the present invention.

[0025] Figure 5 This is a schematic diagram of the drought control system in the second embodiment of the present invention. Detailed Implementation

[0026] The present invention will be further described below with reference to the accompanying drawings and embodiments. Example

[0027] Taking Northwest China as an example, the arid pattern in the region is essentially due to the "blocking" of moisture by mountain ranges. These mountain ranges are not only geographical boundaries but also "watersheds" that determine precipitation distribution. Among them, the Qinghai-Tibet Plateau (south), the Kunlun / Altun Mountains (southwest), the Tianshan Mountains (north), and the Qinling Mountains (east) are the decisive barriers causing drought in Northwest China. Because these mountain ranges encircle the region, this topographical pattern makes it difficult for moist air currents (B) formed by oceanic moisture (Indian Ocean and Pacific Ocean) to enter. The weak westerly winds alone are insufficient to maintain humidity, ultimately leading to a vast temperate desert landscape. This results in the awkward situation where the windward area on one side of the mountain (A) is perpetually humid while the arid area on the other side is perpetually dry. Therefore, the blocking of moist air currents (B) is the main cause of drought in Northwest China, and the relocation of these moist air currents (B) can effectively address the drought problem in the region.

[0028] See Figures 1-3The drought control system involved in this embodiment includes a ventilation duct 1 built along the mountain. The ventilation duct 1 is located in the windward area A1 on one side of the mountain A. The altitude H2 of the air outlet 102 of the ventilation duct 1 is higher than the altitude H1 of the air inlet 101. The air outlet 102 of the ventilation duct 1 extends to the ridgeline A3 of the mountain A. The humid airflow B at low altitude enters the ventilation duct 1 through the air inlet 101, is guided by the ventilation duct 1, and is discharged through the air outlet 102, and finally crosses the ridgeline A3 to reach the drought area A2 on the other side of the mountain A. This system utilizes the suction principle of the chimney effect to draw in the slowly rising humid airflow B in the windward area A1 through the ventilation duct 1. This causes the humid airflow B to rapidly rise in height within the ventilation duct 1, quickly reaching the top of the mountain A. It is then ejected through the outlet 102 of the ventilation duct 1 and crosses the ridgeline A3 to reach the arid area A2 on the other side of the mountain A. The humid airflow B then condenses and forms rainfall, becoming a water source to combat drought. In this system, the operation of ventilation duct 1 requires no other machinery, nor does it consume electricity, fuel, or other energy. It only needs to utilize the smoke window effect generated by ventilation duct 1 to transfer the humid airflow B from the windward area A1 to the arid area A2, thereby enabling the arid area A2 to obtain a large amount of water for land irrigation. This system has no other potential risks. In addition, ventilation duct 1 is built along the mountain, without the need for deep excavation of mountain A, and will not damage the internal rock structure of mountain A, thus having a minimal impact on nature. Moreover, this system has a simple structure, is practical and durable, is a one-time investment with low input costs, low failure rate, easy management, low manpower consumption, and simple and low maintenance costs in the later stage.

[0029] Furthermore, the ventilation area within the ventilation duct 1 gradually increases from the air inlet 101 to the air outlet 102. Under normal circumstances, the volume of the humid airflow B will continuously expand as the altitude increases. The gradually increasing structure can adapt to the gradual decrease in air pressure and the gradual increase in volume of the humid airflow B to reduce air resistance. The cross-sectional shape of the ventilation duct 1 is a geometric shape such as a circle or rectangle, which can be determined according to the terrain of the location.

[0030] However, depending on the actual terrain and environment, the ventilation area in the ventilation duct 1 can be gradually reduced from the air inlet 101 to the air outlet 102, which can lower the center of gravity of the ventilation duct 1 and facilitate construction and fixation; or the ventilation area at different locations in the ventilation duct 1 can be kept consistent, which simplifies the manufacturing difficulty of the ventilation duct 1.

[0031] Furthermore, the air inlet 101 is provided with a funnel-shaped air-gathering and rectifying structure 103. The large end of the air-gathering and rectifying structure 103 faces outward to collect humid airflow B over a wide range. The air-gathering and rectifying structure 103 can expand the suction range and prevent turbulence of humid airflow B from affecting its entry into the ventilation duct 1.

[0032] Furthermore, the outlet end 102 of the ventilation duct 1 should be close to, reach or cross the ridge line A3, so that the humid airflow B ejected from the outlet end 102 (whether by its own inertia or under the action of external force) can smoothly cross the ridge line A3; ensure that the rainwater condensed from the humid airflow B falls within the water-required area of ​​the arid zone A2 without being lost (as long as this purpose is achieved, it can be selected at any height and any location according to the actual local environment such as wind direction, wind force and water content).

[0033] Furthermore, this drought control system also includes a monitoring terminal 2 for monitoring ventilation duct 1 and a detection device group 3 installed on ventilation duct 1. Staff can monitor the operation of ventilation duct 1 through the monitoring terminal 2 to detect and address any anomalies immediately. The detection device group 3 includes a pressure detection device for detecting the internal pressure of ventilation duct 1, a temperature detection device for detecting the internal temperature of ventilation duct 1, a humidity detection device for detecting the internal humidity of ventilation duct 1, and a wind speed detection device for detecting the wind speed of the humid airflow B within ventilation duct 1. The pressure, temperature, humidity, and wind speed detection devices are connected to the monitoring terminal 2 via wired or wireless means. Before the system is put into use, it is necessary to pre-enter data on parameters such as internal pressure, temperature, humidity, and wind speed of ventilation duct 1 under normal operating conditions, as well as the relationships between these parameters. During daily use, staff determine whether the system is functioning correctly based on the actual measured parameter data. The pressure, temperature, humidity, and wind speed detection devices in the detection device group can be selected from one, two, or three, depending on actual needs.

[0034] Furthermore, in order to monitor the operation of the ventilation duct 1 from multiple angles, two or more detection devices of the same type are set along the extension direction of the ventilation duct 1, with at least one detection device set at the air inlet 101 and at least one detection device set at the air outlet 102; when three or more detection devices of the same type are set, the spacing between each pair of adjacent detection devices is preferably equal.

[0035] Furthermore, the air inlet 101 and air outlet 102 are equipped with protective structures to prevent foreign objects from entering the ventilation duct 1. These protective structures have ventilation characteristics. Specifically, the protective structures are preferably guardrails or grilles, which, while ensuring the ventilation performance of the ventilation duct 1 is not affected, also prevent animals and people from entering the ventilation duct 1. The air inlet 101 and air outlet 102 are equipped with duct valves for opening or closing. Specifically, when personnel need to perform maintenance on the ventilation duct 1, the duct valves can be used to temporarily close the ventilation duct 1 to prevent the flow of humid airflow B from affecting the maintenance work. For other work that requires stopping the flow of humid airflow B, the duct valves can also be used to close the ventilation duct 1. Depending on the actual situation, the air inlet 101 and air outlet 102 can be optionally equipped with protective structures, duct valves, or both.

[0036] During the ascent of the moist airflow B, the temperature of the gas decreases due to adiabatic expansion (6°C decreases for every kilometer of altitude increase; for example, if the moist airflow B at the inlet 101 is 20°C, it will decrease by 18°C ​​after rising 3 kilometers without reaching the freezing point). However, at the same time, due to the volume expansion of the moist airflow B, the water vapor is less likely to condense and precipitate (the condensation and precipitation of water vapor requires a certain amount of time and a relatively slow movement speed). Combined with the relatively fast ascent speed and short time of the moist airflow B, the effect of the expansion and heat absorption phenomenon on the flow velocity of the moist airflow B is limited and can be ignored.

[0037] Furthermore, the outer wall of ventilation duct 1 is made of one or more composite materials selected from stainless steel, aluminum alloy, plastic, rubber, and reinforced concrete. The smooth inner wall of ventilation duct 1 reduces friction on humid airflow and the noise generated by friction. Ventilation duct 1 can be directly placed on mountain A or fixed by a support frame. The support frame can be made of durable steel frame materials similar to those used in high-voltage power towers. The inner diameter of ventilation duct 1 can range from several meters to over one hundred meters (when the starting point of ventilation duct 1 is on mountain A, the inner diameter can be within one hundred meters; when the starting point of ventilation duct 1 is in a valley, the inner diameter can be over one hundred meters). The altitude of the highest point of ventilation duct 1 (equivalent to the altitude H2 of the air outlet 102) can range from several thousand meters. The length of ventilation duct 1 can range from several thousand meters to tens of kilometers. Ventilation duct 1 is installed and fixed at an angle according to the slope of the mountain.

[0038] Furthermore, considering the terrain and actual costs, the altitude H1 of the air inlet 101 is preferably below 1000 meters. The lower the altitude, the greater the suction force and the more pronounced the chimney effect. Of course, depending on the actual geographical requirements, the air inlet 101 can also be located at an altitude above 1000 meters.

[0039] Furthermore, for the continuous ridgeline A3, more than one ventilation duct 1 is distributed along the extension direction of the ridgeline A3. This can expand the coverage of the drought control system and ensure that more moist airflows B can cross the ridgeline A3, causing a wider range of precipitation in the drought area A2.

[0040] The calculation method for relevant data (the relevant variable data are assumed within a reasonable range and are for reference only): The following example uses water supply to the Tibet Autonomous Region (see...). Figure 4 ): The average elevation of the mountain A surrounding the Tibet Autonomous Region is about 4,000 meters. The Tibet Autonomous Region is located in the arid zone A2. The wind outlet 102 extends to the ridgeline A3 of the mountain A, which means that the elevation H2 of the wind outlet 102 is 4,000 meters. The average annual temperature in the Tibet Autonomous Region is approximately -6°C. The average annual air pressure P1 in the Tibet Autonomous Region is approximately 60 kPa. The lowest average elevation of the windward area A1 of mountain A is about 1000 meters. The wind inlet 101 starts here, which means that the elevation H1 of the wind inlet 101 is 1000 meters. That is, the elevation difference ΔH between the wind inlet 101 and the wind outlet 102 is ΔH = H2 - H1 = 4000 - 1000 = 3000 meters. The average annual temperature in the windward zone A1 is approximately 20℃. The annual average air pressure P2 in the windward area A1 is approximately 90 kPa; The average relative humidity in the windward area A1 is approximately 70-95%RH throughout the year; if calculated based on saturated water vapor, the air moisture content R is approximately 10-25 g / m³, taking the median value R=15 g / m³.

[0041] The inclination of the windward area A1 is approximately 45°, meaning the horizontal distance L between the air inlet 101 and the air outlet 102 is equal to the elevation difference ΔH = 3000 meters. The length of ventilation duct 1, ΔL = √(L² + ΔH²) = √(3000² + 3000²) ≈ 4242.6 meters (calculated based on the Pythagorean theorem). The air pressure difference between the air inlet 101 and the air outlet 102 is ΔP = P2 - P1 = 90 - 60 = 30 kPa; The humid airflow B in ventilation duct 1 can form a flow velocity V of 22-30 m / s, and we take the middle value V=25 m / s; The time it takes for the humid airflow B to rise from the inlet 10 to the outlet 102 is Δt=ΔL / V=4242.6 / 25≈170s. During the rise, the temperature drop of the humid airflow B is very small and can be ignored. The humid airflow B moves quickly, takes a short time, and its volume expands continuously with the increase of altitude. Therefore, the moisture in the humid airflow B in the ventilation duct 1 cannot condense and is sprayed out from the outlet 102. Finally, it drifts over the vast airspace above the arid area A2. The humid airflow B is then affected by the rapid cooling and forms rainfall.

[0042] Assuming that the cross-section of the air inlet 102 of the ventilation duct 1 is circular and the diameter φ is 40 meters, then its cross-sectional area S = π•(φ / 2)² = 3.14 × (40 ÷ 2)² = 1256㎡; The annual precipitation brought to arid region A2 by the aforementioned ventilation duct 1 is F = S•V•T•R = 1256 × 25 × 31536000 × 15 = 14853456 tons (approximately 1.5 × 10⁻⁶ tons). 7 (tons), where T is one year (in seconds, equivalent to T=3600×24×365=31536000s).

[0043] It is evident that the aforementioned ventilation duct 1 can bring approximately 14,853,456 tons of water to arid region A2 annually, playing a crucial role in drought control. Example

[0044] See Figure 5 The drought control system in this embodiment differs from the first embodiment in that: For certain special situations, such as a small elevation difference between the air inlet 101 and the air outlet 102 resulting in weak suction in the ventilation duct 1, or crosswinds at the air outlet 102 causing obstructed flow of humid airflow B, the flow velocity of humid airflow B may be affected. To address this issue, a fan 4 can be installed within the ventilation duct 1 to assist the humid airflow B in flowing towards the air outlet 102. The fan 4 is matched to the cross-section of the ventilation duct 1. When the fan 4 operates, pressure is generated inside the ventilation duct 1, which pushes the humid airflow B outside the air inlet 101, promoting its flow towards the air outlet 102. This achieves the purpose of actively drawing low-altitude humid airflow B into the ventilation duct 1 and pushing it towards the high-altitude ridgeline 103. The fan 4 is connected to the power grid. The monitoring terminal 2 can be integrated into the control room for convenient operation by staff, and it can also monitor the operation of the fan 4.

[0045] The other undescribed parts are basically the same as those in the first embodiment, and will not be analyzed or explained in detail here.

[0046] The above describes the preferred embodiments of the present invention, illustrating and describing the basic principles, main features, and advantages of the invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A drought control system based on diverting humid airflow from low altitudes, characterized in that: It includes a ventilation duct (1) built along the mountain. The ventilation duct (1) is located in the windward area (A1) on one side of the mountain (A). The altitude H2 of the outlet end (102) of the ventilation duct (1) is higher than the altitude H1 of the inlet end (101). The outlet end (102) of the ventilation duct (1) extends to the ridgeline (A3) of the mountain (A). The humid airflow (B) at low altitude enters the ventilation duct (1) through the inlet end (101), is guided by the ventilation duct (1) and is discharged through the outlet end (102), and finally crosses the ridgeline (A3) to reach the arid area (A2) on the other side of the mountain (A).

2. The drought control system according to claim 1, characterized in that: The ventilation area in the ventilation duct (1) gradually increases or decreases from the air inlet (101) to the air outlet (102); or the ventilation area at different locations in the ventilation duct (1) remains the same.

3. The drought control system according to claim 1, characterized in that: The air inlet (101) is provided with a funnel-shaped air-gathering and rectifying structure (103), with the large end of the air-gathering and rectifying structure (103) facing outward to collect humid airflow (B) over a large area and reduce turbulence resistance.

4. The drought control system according to claim 1, characterized in that: The air outlet (102) of the ventilation duct (1) is close to, reaches or crosses the ridgeline (A3).

5. The drought control system according to claim 1, characterized in that: It also includes a monitoring terminal (2) for monitoring the ventilation duct (1) and a detection device group (3) installed on the ventilation duct (1); the detection device group (3) includes a pressure detection device for detecting the internal pressure of the ventilation duct (1) and / or a temperature detection device for detecting the internal temperature of the ventilation duct (1) and / or a humidity detection device for detecting the internal humidity of the ventilation duct (1) and / or a wind speed detection device for detecting the wind speed of the humid airflow (B) in the ventilation duct (1), and the pressure detection device and / or temperature detection device and / or humidity detection device and / or wind speed detection device are connected to the monitoring terminal (2).

6. The drought control system according to claim 5, characterized in that: Two or more detection devices of the same type are set along the extension direction of the ventilation duct (1), with at least one detection device set at the air inlet (101) and at least one detection device set at the air outlet (102).

7. The drought control system according to claim 1, characterized in that: A fan (4) is installed inside the ventilation duct (1) to assist the flow of humid airflow (B) to the air outlet (102). The fan (4) matches the cross-section inside the ventilation duct (1) and is connected to the power grid.

8. The drought control system according to claim 1, characterized in that: The outer wall of the ventilation duct (1) is made of one or more of stainless steel, aluminum alloy, plastic, rubber, and reinforced cement, and the inner wall of the ventilation duct (1) is smooth.

9. The drought control system according to claim 1, characterized in that: The altitude H1 of the air inlet (101) is below or above 1000 meters.

10. The drought control system according to claim 1, characterized in that: One or more ventilation ducts (1) are distributed along the ridgeline (A3); or, ventilation ducts (1) are set in the valley between two mountains (A).

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