Solar thermal power plant molten salt storage tank foundation ventilation device and method

Abstract

This invention belongs to the technical field of solar thermal power plants, and specifically relates to a ventilation device and method for a molten salt storage tank foundation in a solar thermal power plant. The device includes a molten salt storage tank foundation and a molten salt storage tank installed above the foundation. Multiple horizontal ventilation pipes are evenly distributed at equal intervals inside the foundation. Each horizontal ventilation pipe has a Type I vertical pipe and a Type II vertical pipe connected to its two ends, respectively. An axial flow fan is connected to the top of the Type I vertical pipe, and the top of the Type II vertical pipe is directly connected to the outdoor atmosphere. A temperature sensor array is installed above the horizontal ventilation pipes. This invention achieves a composite ventilation method combining natural convection and decentralized forced ventilation by designing the horizontal ventilation pipes, Type I vertical pipes, and Type II vertical pipes within the tank foundation. When the wind speed is higher than the design wind speed or the outdoor temperature is low, natural ventilation is used; when the wind speed is lower than the design wind speed or the outdoor temperature is high, decentralized forced ventilation is used, ensuring that the heat dissipation of the tank foundation is always effective.

Description

Technical Field

[0001] This invention belongs to the technical field of solar thermal power plants, and specifically relates to a ventilation device and method for the foundation of a molten salt storage tank in a solar thermal power plant. Background Technology

[0002] Solar thermal power generation (CSP) is a technology that converts solar radiation into heat energy through concentrated sunlight, driving a heat engine to generate electricity. Unlike photovoltaic (PV) power generation, which directly utilizes solar radiation, CSP's core lies in its thermal storage system, which stores heat energy to provide continuous and stable power 24 hours a day, earning it the reputation of a self-regulating "never-setting sun." Its basic working principle involves using molten salt or other media to absorb heat energy from solar radiation, converting it into steam energy through equipment and processes, and then driving a steam turbine to generate electricity. Compared to PV power generation, which relies on solar panels to directly convert electricity, CSP not only stores solar heat energy using molten salt but also converts the stored heat energy into steam energy at night, continuously driving a steam turbine to generate electricity. With its stable power supply, flexible regulation, and ability to drive the industrial chain, CSP plays an irreplaceable role in new power systems and forms a complementary development pattern with electrochemical energy storage. From a national strategic perspective, CSP has been given a triple core positioning: "baseline load power source, regulating power source, and industrial chain driver." With the proportion of green electricity continuing to increase, the stability advantage of concentrated solar power (CSP) is becoming increasingly prominent. Unlike the intermittent power generation characteristics of wind and solar power, CSP can achieve continuous and stable power output through thermal storage systems, making it one of the few green power sources capable of supporting base loads.

[0003] In the design of high-temperature molten salt storage tanks for solar thermal power plants, the tank foundation design is particularly critical, and the design of the foundation ventilation system is one of the core aspects of the foundation design. Currently, in the foundations of commercially operational high-temperature molten salt storage tanks, two main ventilation methods are used: natural convection heat transfer and centralized mechanical ventilation heat transfer. Natural ventilation is a non-powered system, and its heat dissipation effect is limited by the external atmospheric environment. When the wind speed in the area where the power plant is located is lower than the design wind speed, the heat inside the foundation is difficult to dissipate effectively, affecting the stability of the tank operation. Centralized forced mechanical ventilation heat transfer uses a powered method, introducing outdoor air into a main pipe (connecting pipe) through a fan, and then distributing it to dozens of horizontal pipes of varying lengths pre-embedded inside the foundation, thus removing the heat inside the foundation through forced ventilation. This ventilation method compensates for the shortcomings of natural ventilation, which depends on meteorological conditions, but it also brings new problems: due to the varying lengths of the branch pipes and the significant differences in airflow resistance between parallel loops, it is difficult to maintain a balanced airflow distributed to each branch pipe through a single main pipe, which easily leads to uneven heat dissipation at the bottom of the tank foundation. Under long-term operation, this uneven heat dissipation causes local damage to the basic structure, leading to uneven settlement of the tank foundation and even causing the tank to tilt, resulting in economic losses and operational risks to the solar thermal power plant. Summary of the Invention

[0004] To address the aforementioned problems, the purpose of this invention is to provide a ventilation device and method for the foundation of a molten salt storage tank in a solar thermal power plant. This invention effectively reduces the impact of random environmental factors on the heat dissipation system by adopting a composite ventilation method that combines natural convection and decentralized forced ventilation in the ventilation design of the storage tank foundation. At the same time, it further avoids the problem of uneven heat dissipation caused by uneven distribution of ventilation volume, effectively improving the overall operational safety and reliability of the power plant.

[0005] The technical solution of the present invention is as follows: a ventilation device for a molten salt tank foundation of a solar thermal power plant, comprising a molten salt tank foundation and a molten salt tank installed above the molten salt tank foundation. Multiple horizontal ventilation pipes are evenly distributed at equal intervals inside the molten salt tank foundation. Each horizontal ventilation pipe has a type I vertical pipe and a type II vertical pipe connected to both ends. The lower parts of the type I and type II vertical pipes are located inside the molten salt tank foundation, and the upper parts extend above the ground. An axial flow fan is connected to the top of the type I vertical pipe, and the top of the type II vertical pipe is directly connected to the outdoor atmosphere. The portions of the type I and type II vertical pipes extending above the ground are distributed circumferentially along the molten salt tank. A temperature sensor array is installed above the horizontal ventilation pipes inside the molten salt tank foundation for real-time monitoring of the foundation temperature.

[0006] Preferably, the temperature sensor group and the axial flow fan are respectively connected to a temperature interlock controller, which is used to control the start and stop of the axial flow fan according to the detection signal of the temperature sensor group.

[0007] Preferably, the temperature sensor group includes a first temperature sensor, a second temperature sensor, a third temperature sensor, a fourth temperature sensor, a fifth temperature sensor, a sixth temperature sensor, a seventh temperature sensor, an eighth temperature sensor, and a ninth temperature sensor. The first temperature sensor is located at the center of the horizontal projection circle of the molten salt storage tank. The second, third, fourth, and fifth temperature sensors are evenly distributed on a circle centered on the center of the horizontal projection circle of the molten salt storage tank. The sixth, seventh, eighth, and ninth temperature sensors are evenly distributed on a circle centered on the center of the horizontal projection circle of the molten salt storage tank, outside the second, third, fourth, and fifth temperature sensors. The second, third, fourth, fifth, sixth, seventh, eighth, and ninth temperature sensors are arranged alternately.

[0008] Preferably, the top height of the type II vertical pipe is higher than the top height of the type I vertical pipe.

[0009] Preferably, the top height of the type II vertical pipe is at least 3 meters higher than the top height of the type I vertical pipe.

[0010] Preferably, the axial flow fan is connected to the type I vertical pipe in a one-to-one correspondence to form a decentralized and independent forced ventilation branch.

[0011] A method for ventilating the foundation of a molten salt storage tank in a solar thermal power plant, using a ventilating device for the foundation of a molten salt storage tank in a solar thermal power plant as described above, includes the following steps: Step 1: Pre-embed multiple horizontal ventilation pipes in the foundation of the molten salt storage tank. Each horizontal ventilation pipe is connected to a Type I vertical pipe and a Type II vertical pipe at both ends. The upper end of the Type I vertical pipe is connected to an axial flow fan, and the upper end of the Type II vertical pipe is directly connected to the outdoor atmosphere. Step 2: Use the temperature sensor group installed in the foundation of the molten salt storage tank to detect the foundation temperature in real time; when the detected temperature is not higher than the set value, turn off the axial flow fan and use the height difference between the Type I and Type II vertical pipes and the outdoor natural wind pressure to achieve natural convection heat dissipation; when the detected temperature is higher than the set value, start the axial flow fan in the corresponding area through the temperature interlock controller, send the outdoor cold air into the ventilation horizontal pipe through the Type I vertical pipe for forced ventilation and heat dissipation, and exhaust the hot air to the outside through the Type II vertical pipe until the foundation temperature drops below the set value and then turn off the axial flow fan.

[0012] The technical advantages of this invention are as follows: 1. This invention uses Type I and Type II ventilation ducts in the tank foundation to form a composite ventilation system that combines natural convection with decentralized forced ventilation. When the outdoor wind speed is higher than the design wind speed or the outdoor temperature is low, natural ventilation is used; when the outdoor wind speed is lower than the design wind speed or the outdoor temperature is high, decentralized forced ventilation is used, ensuring that the heat dissipation of the tank foundation is always effective. 2. The axial flow fan and the ventilation duct are connected one-to-one, avoiding the problem of air volume imbalance caused by connecting pipes. The ventilation effect between each ventilation duct does not affect each other, and the air volume and temperature distribution are uniform, avoiding uneven settlement of the foundation or tilting of the tank caused by local overheating. 3. This invention uses a temperature sensor to detect the foundation temperature in real time, and the temperature interlocking control system automatically controls the start and stop of the axial flow fan without manual intervention. At the same time, it is not affected by accidental factors such as local wind speed and outdoor weather, ensuring the safe and stable operation of the tank foundation and improving the reliability of the solar thermal power plant's thermal storage system.

[0013] The following will provide further explanation in conjunction with the accompanying drawings. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the plan layout of a ventilation device for a molten salt storage tank foundation in a solar thermal power plant, according to the present invention.

[0015] Figure 2 This is a cross-sectional structural schematic diagram of a ventilation device for a molten salt storage tank foundation in a solar thermal power plant, according to the present invention.

[0016] Reference numerals in the attached drawings: 1. Molten salt storage tank foundation; 2. Temperature sensor group; 2-1. First temperature sensor; 2-2. Second temperature sensor; 2-3. Third temperature sensor; 2-4. Fourth temperature sensor; 2-5. Fifth temperature sensor; 2-6. Sixth temperature sensor; 2-7. Seventh temperature sensor; 2-8. Eighth temperature sensor; 2-9. Ninth temperature sensor; 3. Ventilation horizontal pipe; 4. Axial flow fan; 5. Molten salt storage tank; 3-1. Type I vertical pipe; 3-2. Type II vertical pipe. Detailed Implementation

[0017] Example 1 like Figure 1 , Figure 2As shown, a ventilation device for a molten salt tank foundation of a solar thermal power plant includes a molten salt tank foundation 1 and a molten salt tank 5 installed above the molten salt tank foundation 1. Multiple horizontal ventilation pipes 3 are evenly distributed at equal intervals inside the molten salt tank foundation 1. Each horizontal ventilation pipe 3 has a type I vertical pipe 3-1 and a type II vertical pipe 3-2 connected to both ends. The lower parts of the type I vertical pipe 3-1 and type II vertical pipe 3-2 are located inside the molten salt tank foundation 1, while the upper parts extend above the ground. An axial flow fan 4 is connected to the top of the type I vertical pipe 3-1, and the top of the type II vertical pipe 3-2 is directly connected to the outdoor atmosphere. The portions of the type I vertical pipe 3-1 and type II vertical pipe 3-2 extending above the ground are distributed circumferentially along the molten salt tank 5. A temperature sensor group 2 is installed above the horizontal ventilation pipes 3 inside the molten salt tank foundation 1 for real-time monitoring of the foundation temperature.

[0018] In use, the molten salt storage tank 5 generates heat during operation, which is transferred to the molten salt storage tank foundation 1. Outdoor air enters the ventilation horizontal pipe 3 through type I vertical pipe 3-1, absorbs heat from inside the foundation, and is then discharged to the outdoor atmosphere through type II vertical pipe 3-2. When the outdoor wind speed is high or the temperature is low, the height difference between type I vertical pipe 3-1 and type II vertical pipe 3-2 creates a natural pressure difference, achieving natural convection heat dissipation. The temperature sensor group 2 monitors the internal temperature distribution of the foundation in real time, providing a data basis for subsequent control.

[0019] Example 2 Based on Embodiment 1, in this embodiment, preferably, the temperature sensor group 2 and the axial flow fan 4 are respectively connected to a temperature interlock controller, which is used to control the start and stop of the axial flow fan 4 according to the detection signal of the temperature sensor group 2.

[0020] In this invention, the temperature sensor group 2 transmits the detected temperature signals to the temperature interlock controller in real time. The temperature interlock controller compares the temperature of each measuring point with a preset threshold: when the temperature of any measuring point is higher than the set value, the controller automatically starts the corresponding axial flow fan 4; when the temperature of all measuring points drops below the set value, the controller shuts down the axial flow fan 4. This process requires no manual intervention, realizing automatic control of basic ventilation.

[0021] Example 3 Based on Embodiment 1, in this embodiment, preferably, the temperature sensor group 2 includes a first temperature sensor 2-1, a second temperature sensor 2-2, a third temperature sensor 2-3, a fourth temperature sensor 2-4, a fifth temperature sensor 2-5, a sixth temperature sensor 2-6, a seventh temperature sensor 2-7, an eighth temperature sensor 2-8, and a ninth temperature sensor 2-9. The first temperature sensor 2-1 is located at the center of the horizontal projection circle of the molten salt storage tank 5, and the second temperature sensor 2-2, the third temperature sensor 2-3, the fourth temperature sensor 2-4, and the fifth temperature sensor 2-5 are evenly distributed around the horizontal projection circle of the molten salt storage tank 5. On a circle with the center of the circle as its center, the sixth temperature sensor 2-6, the seventh temperature sensor 2-7, the eighth temperature sensor 2-8, and the ninth temperature sensor 2-9 are evenly distributed on the circle outside the second temperature sensor 2-2, the third temperature sensor 2-3, the fourth temperature sensor 2-4, and the fifth temperature sensor 2-5, with the center of the horizontal projection circle of the molten salt storage tank 5 as its center. The second temperature sensor 2-2, the third temperature sensor 2-3, the fourth temperature sensor 2-4, the fifth temperature sensor 2-5, the sixth temperature sensor 2-6, the seventh temperature sensor 2-7, the eighth temperature sensor 2-8, and the ninth temperature sensor 2-9 are arranged alternately.

[0022] In use, the first to ninth temperature sensors 2-1 to 2-9 monitor the temperature distribution at the center, middle circumference, and outer circumference of the molten salt storage tank foundation 1, respectively. The second to fifth temperature sensors 2-2 to 2-5 are evenly distributed on the central circle, and the sixth to ninth temperature sensors 2-6 to 2-9 are evenly distributed on the outer circle and staggered with the inner circle sensors, forming a multi-point grid monitoring system. When the temperature in a certain area rises abnormally, the temperature interlock controller can accurately locate that area and start the corresponding axial flow fan 4 to achieve precise zoned heat dissipation and avoid energy waste caused by overall startup.

[0023] Example 4 Based on Embodiment 1, in this embodiment, preferably, the top height of the type II vertical pipe 3-2 is higher than the top height of the type I vertical pipe 3-1.

[0024] When this invention is used, because the top height of the type II vertical pipe 3-2 is higher than the top height of the type I vertical pipe 3-1, a stable thermal pressure difference is formed between the two vertical pipes under natural ventilation conditions. Hot air is discharged from the upper end of the type II vertical pipe 3-2, and cold air is drawn in from the lower end of the type I vertical pipe 3-1, forming a continuous natural convection circulation, which can effectively remove the internal heat of the foundation without additional power.

[0025] Example 5 Based on Embodiment 1, in this embodiment, preferably, the top height of the Type II vertical pipe 3-2 is at least 3 meters higher than the top height of the Type I vertical pipe 3-1.

[0026] When this invention is used, the top of the type II vertical pipe 3-2 is at least 3 meters higher than the top of the type I vertical pipe 3-1. The thermal pressure difference generated by this height difference is sufficient to overcome the resistance of the ventilation duct, ensuring that natural ventilation can still operate effectively under windless or weak wind conditions. Actual measurements show that when the temperature difference is 10℃, a 3-meter height difference can generate a driving pressure head of about 3.5Pa, which meets the basic heat dissipation requirements.

[0027] Example 6 Based on Example 1, in this embodiment, preferably, the axial flow fan 4 is connected one-to-one with the type I vertical pipe 3-1 to form a decentralized independent forced ventilation branch.

[0028] In this invention, each axial flow fan 4 is independently connected to an I-shaped vertical pipe 3-1, forming decentralized and independent forced ventilation branches. There is no connecting main pipe between these branches, ensuring that airflow does not interfere with each other. When the temperature in a certain area is too high, only the axial flow fan 4 corresponding to that area is activated, while other areas maintain natural ventilation. This structure avoids the problem of uneven airflow distribution caused by varying pipe lengths in centralized ventilation systems, ensuring uniform airflow and consistent heat dissipation within each ventilation horizontal pipe 3.

[0029] Example 7 A method for ventilating the foundation of a molten salt storage tank in a solar thermal power plant, using a ventilating device for the foundation of a molten salt storage tank in a solar thermal power plant as described above, includes the following steps: Step 1: Pre-embed multiple ventilation horizontal pipes 3 in the foundation 1 of the molten salt storage tank. Each ventilation horizontal pipe 3 is connected to a type I vertical pipe 3-1 and a type II vertical pipe 3-2 at both ends. The upper end of the type I vertical pipe 3-1 is connected to an axial flow fan 4, and the upper end of the type II vertical pipe 3-2 is directly connected to the outdoor atmosphere. Step 2: Use the temperature sensor group 2 installed in the molten salt storage tank foundation 1 to detect the foundation temperature in real time; when the detected temperature is not higher than the set value, turn off the axial flow fan 4, and use the height difference between the type I vertical pipe 3-1 and the type II vertical pipe 3-2 and the outdoor natural wind pressure to achieve natural convection heat dissipation; when the detected temperature is higher than the set value, start the axial flow fan 4 in the corresponding area through the temperature interlock controller, send the outdoor cold air into the ventilation horizontal pipe 3 through the type I vertical pipe 3-1 for forced ventilation and heat dissipation, and exhaust the hot air to the outside through the type II vertical pipe 3-2 until the foundation temperature drops below the set value and then turn off the axial flow fan 4.

[0030] In using this invention, first, the installation of the ventilation horizontal pipe 3, type I vertical pipe 3-1, type II vertical pipe 3-2, and axial flow fan 4 is completed according to step one. In step two, the temperature sensor group 2 continuously monitors the base temperature: when the temperature is not higher than the set value, such as 95℃, the temperature interlock controller keeps the axial flow fan 4 off, and natural ventilation is achieved solely by the height difference between type I vertical pipe 3-1 and type II vertical pipe 3-2; when the temperature at any measuring point is higher than the set value, the controller immediately starts the corresponding axial flow fan 4, and the outdoor cold air is forced into type I vertical pipe 3-1, flows through the ventilation horizontal pipe 3 to absorb the base heat, and then the hot air is discharged to the outside from type II vertical pipe 3-2; after the temperature drops below the set value, the controller shuts off the axial flow fan 4, and the system returns to natural ventilation. This process is repeated cyclically to ensure that the base temperature of the storage tank is always within a safe range.

[0031] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A molten salt storage tank foundation ventilation device for a solar thermal power plant, comprising a molten salt storage tank foundation (1) and a molten salt storage tank (5) installed above the molten salt storage tank foundation (1), characterized in that: The molten salt storage tank foundation (1) has multiple ventilation horizontal pipes (3) evenly distributed at equal intervals inside. Each ventilation horizontal pipe (3) is connected to a type I vertical pipe (3-1) and a type II vertical pipe (3-2) at both ends. The lower part of the type I vertical pipe (3-1) and the type II vertical pipe (3-2) are located inside the molten salt storage tank foundation (1), and the upper part extends out of the ground. The top of the type I vertical pipe (3-1) is connected to an axial flow fan (4), and the top of the type II vertical pipe (3-2) is directly connected to the outdoor atmosphere. The parts of the type I vertical pipe (3-1) and the type II vertical pipe (3-2) extending out of the ground are distributed around the molten salt storage tank (5). Inside the molten salt storage tank foundation (1), a temperature sensor group (2) is provided above the ventilation horizontal pipe (3) for real-time detection of the foundation temperature.

2. The molten salt storage tank foundation ventilation device of a solar thermal power station according to claim 1, characterized in that: The temperature sensor group (2) and the axial flow fan (4) are respectively connected to a temperature interlock controller. The temperature interlock controller is used to control the start and stop of the axial flow fan (4) according to the detection signal of the temperature sensor group (2).

3. The molten salt storage tank foundation ventilation device of a solar thermal power station according to claim 2, characterized in that: The temperature sensor group (2) includes a first temperature sensor (2-1), a second temperature sensor (2-2), a third temperature sensor (2-3), a fourth temperature sensor (2-4), a fifth temperature sensor (2-5), a sixth temperature sensor (2-6), a seventh temperature sensor (2-7), an eighth temperature sensor (2-8), and a ninth temperature sensor (2-9). The first temperature sensor (2-1) is located at the center of the horizontal projection circle of the molten salt storage tank (5). The second temperature sensor (2-2), the third temperature sensor (2-3), the fourth temperature sensor (2-4), and the fifth temperature sensor (2-5) are evenly distributed on a circle centered at the center of the horizontal projection circle of the molten salt storage tank (5). The sixth temperature sensor (2-6), the seventh temperature sensor (2-7), the eighth temperature sensor (2-8), and the ninth temperature sensor (2-9) are evenly distributed on a circle centered on the horizontal projection circle of the molten salt storage tank (5) outside the second temperature sensor (2-2), the third temperature sensor (2-3), the fourth temperature sensor (2-4), and the fifth temperature sensor (2-5). The second temperature sensor (2-2), the third temperature sensor (2-3), the fourth temperature sensor (2-4), the fifth temperature sensor (2-5), the sixth temperature sensor (2-6), the seventh temperature sensor (2-7), the eighth temperature sensor (2-8), and the ninth temperature sensor (2-9) are arranged alternately.

4. The molten salt storage tank foundation ventilation device of a solar thermal power station according to claim 2, characterized in that: The top height of the type II vertical pipe (3-2) is higher than the top height of the type I vertical pipe (3-1).

5. A molten salt storage tank foundation venting apparatus for a solar thermal power plant according to claim 4, wherein: The top height of the type II vertical pipe (3-2) is at least 3 meters higher than the top height of the type I vertical pipe (3-1). The height difference is mainly used to provide a thermal pressure difference for natural ventilation heat exchange.

6. A molten salt storage tank foundation venting apparatus for a solar thermal power plant according to claim 5, wherein: The axial flow fan (4) is connected to the type I vertical pipe (3-1) in a one-to-one correspondence to form a decentralized independent forced ventilation branch.

7. A method for ventilating the foundation of a molten salt storage tank in a solar thermal power plant, using the ventilation device for the foundation of a molten salt storage tank in a solar thermal power plant as described in claim 6, characterized in that: Includes the following steps: Step 1: Pre-embed multiple ventilation horizontal pipes (3) in the foundation (1) of the molten salt storage tank. Each ventilation horizontal pipe (3) is connected to a type I vertical pipe (3-1) and a type II vertical pipe (3-2) at both ends. The upper end of the type I vertical pipe (3-1) is connected to an axial flow fan (4), and the upper end of the type II vertical pipe (3-2) is directly connected to the outdoor atmosphere. Step 2: Use the temperature sensor group (2) installed in the molten salt storage tank foundation (1) to detect the foundation temperature in real time; when the detected temperature is not higher than the set value, turn off the axial flow fan (4) and use the height difference between the type I vertical pipe (3-1) and the type II vertical pipe (3-2) and the outdoor natural wind pressure to achieve natural convection heat dissipation; when the detected temperature is higher than the set value, start the axial flow fan (4) in the corresponding area through the temperature interlock controller, send the outdoor cold air into the ventilation horizontal pipe (3) through the type I vertical pipe (3-1) for forced ventilation heat dissipation, and exhaust the hot air to the outside through the type II vertical pipe (3-2) until the foundation temperature drops below the set value and then turn off the axial flow fan (4).

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