Tunnel type semi-underground total exhaust fan room system of pumped storage power station and design method thereof

Abstract

The application discloses a tunnel type semi-underground total exhaust fan room system of pumped storage power station and a design method thereof. An exhaust adit and a fan room tunnel form a "T-shaped" tunnel, and the total exhaust fan room is arranged in the fan room tunnel. The entrance of the fan room tunnel is adjacent to a mountain road. The application reduces the slope excavation and slope support work of the ground total exhaust fan room platform. The exhaust adit is directly connected with the fan room tunnel. After the fan room tunnel is opened, the exhaust adit can be directly excavated, and the excavation of the exhaust adit does not have to wait for the completion of the slope excavation and slope support work of the ground total exhaust fan room platform, thereby reducing the construction period and being beneficial to opening the whole exhaust passage as early as possible, thus creating favorable conditions for the ventilation of the underground powerhouse. The fan room tunnel is adjacent to the existing mountain road during site selection, the existing mountain road resources can be well utilized, the road construction work leading to the total exhaust fan room is reduced, the construction period is greatly reduced, and the engineering investment is saved.

Description

Technical Field

[0001] This invention relates to the field of water conservancy and hydropower engineering technology, specifically to a tunnel-type semi-underground main exhaust fan room system for pumped storage power stations and its design method. Background Technology

[0002] Pumped-storage power stations are typically located in mountainous areas, with the main powerhouse mostly situated underground. Daily operation and maintenance of these underground powerhouses require ventilation, typically achieved through mechanical air supply and exhaust systems. The underground powerhouse complex is intricate, and different areas may have separate local air supply and exhaust systems depending on their usage characteristics. However, all exhaust air ultimately flows out to the outside atmosphere through fans in the main exhaust fan room. In some pumped-storage power station planning, the main exhaust fan room is initially planned to be located above ground. In such cases, it's necessary to find or construct a surface platform for the main exhaust fan room in the mountainous area. This platform should ideally be located near existing roads or easily accessible by road. To achieve optimal ventilation and minimize excavation work, the length of the exhaust duct between the surface main exhaust fan room and the underground powerhouse should be as short as possible. However, during the construction of some power plants, it was found that the slopes near existing roads in mountainous areas are too steep, requiring extensive slope excavation and support work for the generator room platform, making it difficult to create suitable conditions for setting up a ground-level main exhaust generator room platform. Conversely, some areas with relatively gentle terrain lack direct roads; if the exhaust generator room platform were located in such areas, a new road would need to be built, and in some cases, tunnels would need to be excavated through the mountains, inevitably leading to longer construction periods and increased investment. Therefore, it is necessary to provide a design method for the main exhaust generator room of pumped storage power plants that can effectively utilize existing hillside road resources, reduce reliance on slope excavation and support for ground-level generator room platforms, and lower construction investment. Summary of the Invention

[0003] In view of the shortcomings of existing technologies and in light of the characteristics of actual engineering projects, this invention provides a tunnel-type semi-underground main exhaust fan room system for pumped storage power stations and its design method, which can effectively solve the above-mentioned practical engineering problems.

[0004] The technical solution adopted in this invention is as follows: a semi-underground main exhaust fan room system for a pumped storage power station, wherein an exhaust shaft is set at the top of one end of the underground powerhouse, and an exhaust horizontal tunnel is set at the top of the exhaust shaft. The exhaust horizontal tunnel is connected to the fan room tunnel. One end of the fan room tunnel is adjacent to a hillside road. The fan room tunnel is divided into an air intake equalization chamber, a main exhaust fan room, an electrical equipment room, an operation and maintenance corridor, an exhaust channel, a tunnel-road connection transition section, and a tunnel exhaust section. Fans and air intake and exhaust pipes are set in the main exhaust fan room. The air intake equalization chamber is directly vertically connected to the exhaust horizontal tunnel, so that the exhaust horizontal tunnel and the fan room tunnel form a "T" shaped structure.

[0005] Furthermore, the fan and the suction and exhaust pipe consist of an exhaust fan, a suction pipe, and an exhaust pipe; the exhaust fan is of the horizontal inlet and upward outlet type, the suction pipe is set parallel to the ground and connected to the suction end of the exhaust fan, and the exhaust pipe is set perpendicular to the ground and connected to the exhaust end of the exhaust fan.

[0006] Furthermore, the outlet section of the exhaust duct is located in the middle of the air intake equalization chamber.

[0007] Furthermore, the machine room tunnel is arranged in the following order in the horizontal direction: tunnel exhaust section, main exhaust fan room and air intake equalization chamber and exhaust duct, electrical equipment room and maintenance corridor, and tunnel-road connection transition section. The main exhaust fan room, air intake equalization chamber and exhaust duct are on the same cross section of the machine room tunnel. The exhaust duct is above the main exhaust fan room. The air intake equalization chamber is on one side of the exhaust duct and main exhaust fan room. The electrical equipment room and maintenance corridor are on the same cross section of the machine room tunnel. The electrical equipment room and maintenance corridor are arranged adjacent to each other on the left and right. The tunnel-road connection transition section is connected to the hillside road. The tunnel exhaust section leads directly to the outside.

[0008] Furthermore, louvered air vents are installed on the wall at the end of the exhaust duct, and the total area of ​​the louvered air vents is not less than 0.6 times the cross-sectional area of ​​the exhaust duct.

[0009] Furthermore, the exhaust duct can be straight or curved.

[0010] Furthermore, the bottom of the ventilation tunnel is flush with the bottom of the machine room tunnel.

[0011] Furthermore, the width of the air intake equalization chamber is not less than 2 meters; the number of exhaust fans is 3-6.

[0012] Furthermore, the cross-section of the machine room tunnel is made into a horseshoe shape.

[0013] The design method for the tunnel-type semi-underground main exhaust fan room system of the above-mentioned pumped storage power station includes the following steps:

[0014] Step 1: In the area directly above the underground plant, along the hillside road, find a location that is suitable for excavation to form a machine room tunnel;

[0015] Step 2: Based on the terrain conditions, measure and calculate the total length L0 of the tunnel that runs from one side of the hillside road to the other side;

[0016] Step 3: Determine the total exhaust volume Q of the underground plant: Calculate the minimum ventilation volume Q1 required to meet the air change rate requirement, calculate the minimum ventilation volume Q2 required to exhaust the heat generated by the electromechanical equipment in the underground plant, calculate the minimum ventilation volume Q3 for areas with emergency exhaust requirements, and calculate the minimum smoke exhaust volume Q4 in the smoke control system design. The total exhaust volume Q of the underground plant is taken as the maximum value among Q1, Q2, Q3 and Q4.

[0017] Step 4: Determine the size of a single exhaust fan under different combinations of fan numbers based on the total exhaust volume Q value calculated in Step 3.

[0018] If 3 exhaust fans are selected, the exhaust volume of a single exhaust fan is Q / 3. Using this exhaust volume and referring to the fan specifications provided by the manufacturer, determine the specific dimensions of the corresponding fan model for this exhaust volume: Length × Width × Height = l 1× d 1× h 1. Using this method, calculate the specific dimensions of a single exhaust fan when selecting 4 exhaust fans: Length × Width × Height = l 2× d 2× h 2. For a system with 5 exhaust fans, the specific dimensions of a single exhaust fan are: Length × Width × Height = l 3× d 3× h 3. Under the condition of 6 exhaust fans operating, the specific dimensions of a single exhaust fan: Length × Width × Height = l 4× d 4× h 4;

[0019] Step 5: Determine the length of the total exhaust fan room for different combinations of exhaust fan numbers, the maximum length of the electrical equipment room corresponding to the total power consumption of the exhaust fans under the corresponding operating conditions, and the sum of the two, L. a To facilitate the installation, operation, and maintenance of the fans, the minimum distance between the fans and the side walls, as well as between adjacent fans, is 1.5 meters.

[0020] The total length of the exhaust fan room corresponding to the 3 exhaust fans is L1: L1=3 l 1 + 4 × 1.5m; The maximum length of the electrical equipment room corresponding to the total power consumption of 3 exhaust fans is denoted as L. 11 At this time, the length L1 of the main exhaust fan room and the maximum length L of the electrical equipment room are... 11 Sum of: L a1= L1+ L 11 ;

[0021] The total length of the exhaust fan room corresponding to 4 exhaust fans is L2: L2=3 l 2 + 5 × 1.5m; The maximum length of the electrical equipment room corresponding to the total power consumption of 4 exhaust fans is denoted as L. 22 At this point, the length L2 of the main exhaust fan room and the maximum length L of the electrical equipment room are... 22 Sum of: L a2 = L2+ L 22 ;

[0022] The total length of the exhaust fan room corresponding to 5 exhaust fans is L3: L3=3 l 3 + 6 × 1.5m; The maximum length of the electrical equipment room corresponding to the total power consumption of 5 exhaust fans is denoted as L. 33 At this point, the length L3 of the main exhaust fan room and the maximum length L of the electrical equipment room are... 33 Sum of: L a3 = L3+ L 33 ;

[0023] The total length of the exhaust fan room for 6 exhaust fans is L4: L4=3 l 4 + 7 × 1.5m; The maximum length of the electrical equipment room corresponding to the total power consumption of 6 exhaust fans is denoted as L. 44 At this point, the length L4 of the main exhaust fan room and the maximum length L of the electrical equipment room are... 44 Sum of: L a4 = L4+ L 44 ;

[0024] Step 6: Determine the minimum total length L of the tunnel-road connection transition section and the tunnel ventilation section. b Based on the premise that the distance between the top of the tunnel ventilation section and the outer hillside is not less than 3 meters, L was measured and calculated. b1 Based on the premise that the distance between the top of the tunnel-road transition section and the outer hillside is not less than 10 meters, L is measured and calculated. b2 Thus, L can be obtained. b = L b1 + L b2 ;

[0025] Step 7: Determine the number of exhaust fans to be installed; compare L under different combinations of exhaust fan quantities. a + L b And the size of L0;

[0026] Assuming the length L0 of the machine room tunnel meets the requirements, the excavation of the cross-section should be minimized as much as possible, i.e., the number of exhaust fans should be increased while the width and height of each exhaust fan should be reduced. The following conclusions can be drawn:

[0027] If L a4 + L b If L0 is less than or equal to L0, then select 6 exhaust fans;

[0028] If L a4 + L b > L0≥ L a3 + L b If so, then select 5 exhaust fans;

[0029] If L a3 + L b > L0≥ L a2 + L b If so, then select 4 exhaust fans;

[0030] If L a2 + L b > L0≥ L a1 + L b If so, then select 3 exhaust fans;

[0031] L0< L a1 + L b If so, it means that the length of L0 is insufficient, and the data center tunnel needs to be replanned and selected.

[0032] Step 8: Calculate the minimum width D of the main exhaust fan room. a and minimum height H a Based on the comparison results in step 7, determine the number of exhaust fans to be installed, and determine the dimensions of a single exhaust fan: i.e., length × width × height = l p × d p × h p The cross-sectional dimensions of the intake and exhaust ducts are determined based on the air volume of a single exhaust fan and the wind speed conditions specified in the standard. The lengths of the intake and exhaust ducts meet the minimum distance requirements for the installation of the air valve. The minimum installation length of the intake duct is denoted as... l g The minimum installation length of the exhaust duct is denoted as h g Find the minimum height H of the main exhaust fan room. a H a = h p + h g To meet the transportation and maintenance requirements of the innermost exhaust fan in the main exhaust fan room, the width of the maintenance space within the main exhaust fan room shall not be less than [amount missing]. d p Given +1.0m, find the minimum width D of the main exhaust fan room. a Da = d p + h g + d p + 1.0m;

[0033] Step 9: Minimum width D0 of the computer room tunnel: The width of the air intake equalization chamber shall not be less than 2m, considering a 0.2m thick partition wall, combined with the minimum width D of the main exhaust fan room calculated in Step 8. a Calculate D0 = D a + 2m +0.2m

[0034] Step 10: Calculate the height H of the exhaust duct. b The total area of ​​the louvered air vents should be no less than 0.6 times the cross-sectional area of ​​the exhaust duct, according to the maximum air velocity of the exhaust vents as required by the specifications. v max1 And based on the total exhaust volume Q calculated above, calculate the minimum effective area F of the louvered air vent. min1 = Q / v max1 Then, use the following formula to calculate the height H of the exhaust duct. b :

[0035] F min1 = H b × D a × μ 1× μ 2× μ 3

[0036] in, μ 1 is the ratio of the total area of ​​the louvered air vents to the cross-sectional area of ​​the exhaust duct, with a value of 0.6; μ 2 is the effective exhaust area coefficient of the louvered air outlet considering factors such as obstruction, and is taken as 0.8; μ 3 is the verification coefficient for non-rectangular sections of the exhaust duct, with a value of 0.9;

[0037] Step 11: Determine the minimum height H0 of the machine room tunnel: Considering a 0.2m thick concrete partition slab, H0 = H a + H b +0.2m;

[0038] Step 12: Determine the cross-sectional excavation dimensions of the machine room tunnel; combining the D0 value calculated in Step 9 and the H0 value calculated in Step 11, considering the lining after excavation and the minimum value calculation method of the above calculation process, the height and width of the machine room tunnel can be excavated according to 1.2 times H0 and 1.2 times D0 respectively.

[0039] The beneficial effects of this invention are:

[0040] 1) By placing the main exhaust fan room of the pumped storage power station in the tunnel, the slope excavation and slope support work of the ground main exhaust fan room platform is reduced, thus shortening the construction period;

[0041] 2) The exhaust tunnel of the underground plant is connected to the machine room tunnel where the main exhaust fan room is located in a "T" shape. The exhaust tunnel is directly connected to the machine room tunnel. After the machine room tunnel is opened, the exhaust tunnel can be excavated directly without waiting for the slope excavation and slope support work of the main exhaust fan room platform on the ground to be completed before the exhaust tunnel is excavated. This is conducive to opening up the entire exhaust channel as soon as possible and creating favorable conditions for ventilation of the underground plant.

[0042] 3) The tunnel site for the main exhaust fan room of the pumped storage power station is located close to the existing hillside road, which makes good use of the existing hillside road resources and reduces the road construction work leading to the main exhaust fan room. This not only greatly reduces the construction period but also saves project investment, and has broad guiding and promotion significance. Attached Figure Description

[0043] Figure 1 This is a plan view of the tunnel-type semi-underground main exhaust fan room system for pumped storage power stations according to the present invention.

[0044] Figure 2 This is section A-A of the plan view of the semi-underground main exhaust fan room system of the pumped storage power station tunnel of the present invention.

[0045] Figure 3 This is section B-B of the schematic plan of the semi-underground main exhaust fan room system of the pumped storage power station tunnel of the present invention.

[0046] Figure 4 This is section C-C of the plan view of the semi-underground main exhaust fan room system of the pumped storage power station tunnel of the present invention.

[0047] Figure 5 This is a schematic diagram showing the dimensions of the pumped storage power station tunnel-type semi-underground main exhaust fan room system of the present invention.

[0048] Figure 6 This is a schematic diagram showing the cross-sectional dimensions of the pumped storage power station tunnel-type semi-underground main exhaust fan room system of the present invention.

[0049] In the diagram, the arrows indicate the direction of airflow. For ease of illustration, the lines in the diagram are only used to show the outline and do not represent the actual thickness of the walls or the actual style of the cavern walls. Detailed Implementation

[0050] To make the technical problems solved, the technical solutions, and the beneficial effects of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the invention.

[0051] In the description of this invention, it should be noted that the terms "upper," "lower," "inner," "outer," "top / bottom," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," "third," "fourth," and "fifth" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0052] like Figure 1-6 As shown, the pumped storage power station tunnel-type semi-underground main exhaust fan room system of the present invention includes an underground powerhouse 1, an exhaust shaft 2, an exhaust tunnel 3, a fan room tunnel 4, a partition door, a partition wall, a concrete partition, a fan and an intake and exhaust duct 8, a louvered air outlet 9, a hillside road 10, and a mountain 11.

[0053] An exhaust shaft 2 is installed at the top of one end of the underground plant 1. An exhaust tunnel 3 is installed at the top of the exhaust shaft 2. The exhaust tunnel 3 is connected to the machine room tunnel 4. One end of the machine room tunnel 4 is adjacent to the hillside road 10.

[0054] In the machine room tunnel 4, partition doors, partition walls and concrete partitions 7 are used to divide the machine room tunnel 4 into an air intake equalization chamber 4-1, a main exhaust fan room 4-2, an electrical equipment room 4-3, an operation and maintenance corridor 4-4, an exhaust duct 4-5, a tunnel-road connection transition section 4-6 and a tunnel exhaust section 4-7.

[0055] The partition wall consists of a first partition wall 6-1, a second partition wall 6-2, a third partition wall 6-3, a fourth partition wall 6-4, and a fifth partition wall 6-5; the partition door 5 consists of a first partition door 5-1, a second partition door 5-2, a third partition door 5-3, and a fourth partition door 5-4; the first partition door 5-1 is installed on the second partition wall 6-2, the second partition door 5-2 is installed on the third partition wall 6-3, the third partition door 5-3 is installed on the fifth partition wall 6-5, and the fourth partition door 5-4 is installed on the fourth partition wall 6-4.

[0056] In the machine room tunnel 4, along the tunnel-road connection transition section 4-6 towards the tunnel exhaust section 4-7, the lower space formed by the right side of the first partition wall 6-1, the second partition wall 6-2, the right side of the first partition door 5-1, the third partition wall 6-3, the second partition door 5-2, and the concrete partition is the main exhaust machine room 4-2; the upper space formed by the right side of the first partition wall 6-1, the second partition wall 6-2, the third partition wall 6-3, and the concrete partition is the exhaust duct 4-5; the left side of the first partition wall 6-1, the second partition wall 6-2, and the left side of the third partition wall 6-3... The side partition forms an air intake equalization chamber 4-1; the left side of the third partition wall 6-3, the left side of the fifth partition wall 6-5, and the fourth partition wall 6-4 form an electrical equipment room 4-3; the right side of the third partition wall 6-3, the second partition door 5-2, the right side of the fifth partition wall 6-5, the third partition door 5-3, and the fourth partition wall 6-4 form an operation and maintenance corridor 4-4; the area between the fifth partition wall 6-5 and one end of the machine room tunnel 4 forms a tunnel-road connection transition section 4-6; the area between the second partition wall 6-2 and the other end of the machine room tunnel 4 forms a tunnel exhaust section 4-7.

[0057] A louvered air vent 9 is installed on the second partition wall 6-2 at the end of the exhaust duct 4-5.

[0058] Preferably, the size and number of louvered air vents 9 should be designed to occupy as much of the effective area of ​​the second partition wall 6-2 at the end of the exhaust duct 4-5 as possible, and the total area of ​​louvered air vents 9 should be no less than 0.6 times the cross-sectional area of ​​the exhaust duct 4-5.

[0059] A fan and suction / exhaust duct are installed in the main exhaust fan room 4-2. The fan and suction / exhaust duct consist of an exhaust fan 8-1, a suction duct 8-2, and an exhaust duct 8-3.

[0060] Preferably, in order to save the horizontal space occupied by the fan and duct in the machine room, the exhaust fan 8-1 is customized to be horizontally inlet and upwardly outlet, the suction duct 8-2 is set to be parallel to the ground and connected to the suction end of the exhaust fan 8-1, and the exhaust duct 8-3 is set to be perpendicular to the ground and connected to the exhaust end of the exhaust fan 8-1.

[0061] Preferably, the exhaust tunnel 3 can be made into a straight line or a curved line. It should be ensured that the exhaust tunnel 3 is vertically connected to the suction pressure equalization chamber 4-1, so that the exhaust tunnel 3 and the machine room tunnel 4 form a "T" shape structure. In order to ensure that the multiple exhaust fans 8-1 installed in the main exhaust machine room 4-2 can draw air evenly and the air volume can be evenly distributed on both sides of the suction pressure equalization chamber 4-1, and to avoid excessive local resistance, it is necessary to ensure that the outlet section of the exhaust tunnel 3 is located in the middle of the suction pressure equalization chamber 4-1.

[0062] Preferably, considering that the exhaust fan 8-1 is installed on the ground in the main exhaust fan room 4-2, the air intake pipe 8-2 is close to the main exhaust fan room 4-2, and in order to facilitate the excavation of the tunnel, the bottom of the exhaust tunnel 3 needs to be flush with the bottom of the machine room tunnel 4.

[0063] Preferably, in order to ensure the uniformity of the intake airflow, the width of the intake equalization chamber 4-1 should not be less than 2 meters.

[0064] Preferably, in order to facilitate operation and maintenance management, different numbers of fans are turned on under different seasonal conditions. The number of exhaust fans 8-1 should not be less than 3 and should not exceed 6.

[0065] Preferably, in order to ensure the stability of the tunnel structure, the cross-section of the machine room tunnel 4 is made into a "horseshoe" shape.

[0066] Preferably, the cross-sectional excavation dimensions of the machine room tunnel 4, the location of the concrete partition slabs, and the dimensions and quantity of the exhaust fans 8-1 should be determined by comparison using the following method:

[0067] Step 1: In the area directly above the underground plant 1, along the hillside road 10, find a location that meets the conditions for excavation to form the machine room tunnel 4.

[0068] Step 2: Based on the terrain conditions, measure and calculate the total length L of the tunnel 4 from one side of the hillside road 10 to the other side within the mountain 11. 0。

[0069] Step 3: Determine the total exhaust volume Q of underground plant 1, calculate the minimum ventilation volume Q1 to meet the air exchange rate requirement, calculate the minimum ventilation volume Q2 required to exhaust the heat generated by the electromechanical equipment in underground plant 1, calculate the minimum ventilation volume Q3 for areas with emergency exhaust requirements, and calculate the minimum smoke exhaust volume Q4 in the smoke control system design. The total exhaust volume Q of underground plant 1 is taken as the maximum value among Q1, Q2, Q3 and Q4.

[0070] Step 4: Therefore, based on the total exhaust volume Q calculated in Step 3, determine the size of a single exhaust fan 8-1 under different combinations of fan numbers. Different fan volumes correspond to different fan sizes; the larger the fan volume, the larger the fan size. For example, if 3 exhaust fans 8-1 are selected, the exhaust volume of a single exhaust fan 8-1 is Q / 3. Using this exhaust volume and referring to the fan samples provided by the fan manufacturer, find the specific dimensions of the corresponding fan model under this exhaust volume condition: Length × Width × Height = l 1× d 1× h 1; Using this method, calculate the specific dimensions of a single exhaust fan 8-1 under the condition of selecting 4 exhaust fans 8-1: length × width × height = l 2×d 2× h 2. Under the condition of 5 exhaust fans 8-1, the specific dimensions of a single exhaust fan 8-1 are: Length × Width × Height = l 3× d 3× h 3. Under the condition of 6 exhaust fans 8-1, the specific dimensions of a single exhaust fan 8-1 are: Length × Width × Height = l 4× d 4× h 4.

[0071] Step 5: Determine the length of the total exhaust fan room 4-2 for different combinations of exhaust fans 8-1, and the maximum length of the electrical equipment room 4-3 corresponding to the total power consumption of exhaust fans 8-1 under the corresponding operating conditions, as well as the sum of the two, L. a .

[0072] The length L1 of the main exhaust fan room 4-2 corresponding to the 3 exhaust fans 8-1 is: L1=3 l 1 + 4 × 1.5m To facilitate the installation, operation, and maintenance of the fans, the minimum distance between the fans and the side walls, as well as between adjacent fans, is 1.5 meters. In the formula, "m" represents the unit of meters. The maximum length of the electrical equipment room 4-3 corresponding to the total power consumption of the three exhaust fans 8-1 is denoted as L. 11 At this time, the length L1 of the main exhaust fan room 4-2 and the maximum length L of the electrical equipment room 4-3 are... 11 Sum of: L a1 = L1+ L 11 .

[0073] The length L2 of the main exhaust fan room 4-2 corresponding to the 4 exhaust fans 8-1 is: L2=3 l 2 + 5 × 1.5m; The maximum length of the electrical equipment room 4-3 corresponding to the total power consumption of 4 exhaust fans 8-1 is denoted as L. 22 At this time, the length L2 of the main exhaust fan room 4-2 and the maximum length L of the electrical equipment room 4-3 are... 22 Sum of: L a2 = L2+ L 22 .

[0074] The length L3 of the main exhaust fan room 4-2 corresponding to the 5 exhaust fans 8-1 is: L3=3 l 3 + 6 × 1.5m; The maximum length of the electrical equipment room 4-3 corresponding to the total power consumption of 5 exhaust fans 8-1 is denoted as L. 33 At this time, the length L3 of the main exhaust fan room 4-2 and the maximum length L of the electrical equipment room 4-3 are... 33 Sum of: L a3 = L3+ L 33 .

[0075] The total exhaust fan room 4-2 corresponding to the 6 exhaust fans 8-1 has a length L4: L4=3 l 4 + 7 × 1.5m; The maximum length of the electrical equipment room 4-3 corresponding to the total power consumption of 6 exhaust fans 8-1 is denoted as L. 44 At this point, the length L4 of the main exhaust fan room 4-2 and the maximum length L of the electrical equipment room 4-3 are... 44 Sum of: L a4 = L4+ L 44 .

[0076] Step 6: Determine the minimum total length L of the tunnel-road connection transition section 4-6 and the tunnel ventilation section 4-7. b Based on the fact that the distance between the top of the tunnel ventilation section 4-7 and the outer hillside is not less than 3 meters, L was measured and calculated. b1 Based on the premise that the distance between the top of the tunnel-road transition section 4-6 and the outer hillside is not less than 10 meters, L is measured and calculated. b2 Thus, L can be obtained. b = L b1 + L b2 .

[0077] Step 7: Determine the number of exhaust fans 8-1 to be installed; compare L under different combinations of exhaust fan 8-1 quantities. a + L b The size of L0.

[0078] One principle needs to be met: Provided that the length L0 of the machine room tunnel 4 meets the requirements, the excavation of the cross-section should be minimized as much as possible. This means increasing the number of exhaust fans 8-1 and reducing the width and height of each exhaust fan 8-1. Therefore, the following conclusions are drawn:

[0079] If L a4 + L b If L0 is less than or equal to 6, then select 6 exhaust fans (8-1).

[0080] If L a4 + L b > L0≥ L a3 + L b Then select 5 exhaust fans 8-1;

[0081] If L a3 + L b > L0≥ L a2 + L b Then select 4 exhaust fans 8-1;

[0082] If L a2 + L b > L0≥ L a1 + Lb Then select 3 exhaust fans 8-1;

[0083] L0< L a1 + L b If so, it means that the length of L0 is insufficient, and the computer room tunnel 4 needs to be replanned and selected.

[0084] Step 8: Calculate the minimum width D of the main exhaust fan room 4-2. a and minimum height H a Based on the comparison results in step 7, the number of exhaust fans 8-1 can be determined, thus determining the dimensions of a single exhaust fan 8-1: length × width × height = l p × d p × h p Based on the air volume of a single exhaust fan 8-1 and the wind speed conditions specified in the standard, determine the cross-sectional dimensions of the suction pipe 8-2 and the exhaust pipe 8-3. The lengths of the suction pipe 8-2 and the exhaust pipe 8-3 must meet the minimum distance requirements for the installation of the air valve. The minimum installation length of the suction pipe 8-2 is denoted as... l g The minimum installation length of the exhaust duct 8-3 is denoted as h g At this point, the minimum height H of the main exhaust fan room can be calculated. a H a = h p + h g To meet the transportation and maintenance requirements of the innermost exhaust fan 8-1 in the main exhaust fan room 4-2, the width of the maintenance space within the main exhaust fan room 4-2 shall not be less than [amount missing]. d p + During the transportation of the 1.0m fan, the safe distance from the side wall and the edge of the fan is 0-5 meters each, thus obtaining the minimum width D of the main exhaust fan room 4-2. a D a = d p + h g + d p + 1.0m.

[0085] Step 9: Minimum width D0 of computer room tunnel 4; Based on the above description, the width of the suction equalization chamber 4-1 should not be less than 2m. Considering the 0.2m thick partition wall 6-1, and combining the minimum width D of the main exhaust fan room 4-2 calculated in Step 8... a D0 = D can be calculated a + 2m +0.2m.

[0086] Step 10: Calculate the height H of exhaust duct 4-5 b According to the above requirements, the total area of ​​the louvered air vent 9 should be no less than 0-6 times the cross-sectional area of ​​the exhaust duct 4-5, and the maximum air velocity of the exhaust vent should be within the range specified in the standard. v max1 Based on the total exhaust volume Q calculated above, calculate the minimum effective area F of the louvered vent 9. min1 = Q / v max1 Then, use the following formula to calculate the height H of the exhaust duct 4-5. b :

[0087] F min1 = H b × D a × μ 1× μ 2× μ 3

[0088] in, μ 1 is the percentage coefficient of the total area of ​​the louvered air vent 9 to the cross-sectional area of ​​the exhaust duct 4-5, with a value of 0.6; μ 2 is the effective exhaust area coefficient of the louvered air vent 9, taking into account factors such as obstruction, and is set to 0.8; μ 3 is the verification coefficient for the non-rectangular cross-section of the exhaust duct 4-5, with a value of 0.9.

[0089] Step 11: Determine the minimum height H0 of the machine room tunnel 4; considering the 0.2m thick concrete partition 7, H0 = H a +H b + 0.2m.

[0090] Step 12: Determine the cross-sectional excavation dimensions of the machine room tunnel 4; combining the D0 value calculated in Step 9 and the H0 value calculated in Step 11, considering the lining after excavation and the minimum value calculation method of the above calculation process, the height and width of the machine room tunnel 4 can be excavated according to 1.2 times H0 and 1.2 times D0 respectively.

[0091] This invention provides a "T-shaped" tunnel-type semi-underground main exhaust fan room for a pumped storage power station. This design places the main exhaust fan room within a tunnel. One side of the tunnel is adjacent to an existing hillside road, making good use of existing road resources and reducing the need for road construction to the main exhaust fan room. The other side provides direct access to the atmosphere, forming a semi-underground main exhaust fan room. This design solves the problem of slope excavation and support work for the surface main exhaust fan room platform in traditional solutions. After the tunnel is completed, the exhaust tunnel can be excavated directly without waiting for the surface main exhaust fan room platform's slope excavation and support work to be completed. This facilitates the early opening of the entire exhaust channel, creating favorable conditions for ventilation in the underground powerhouse, thereby reducing the construction period and lowering project investment.

[0092] The following description, using a large-scale pumped storage power station project that employs the technical solution of this invention as an example, is further illustrated with reference to the accompanying drawings:

[0093] A large pumped-storage power station has its underground powerhouse located at the foot of a mountain. The original ventilation system design planned to place the main exhaust fan room above ground. However, due to the steep slopes along the road, the selection of the main exhaust fan room platform needed to consider safety and stability, minimizing slope excavation and support work. After comprehensive assessment of the actual terrain, the platform for the main exhaust fan room was ultimately located on a gentler section of the mountainside. However, this gentler slope was separated from the mountain road by a mountain, necessitating the construction of a tunnel. This tunnel has now been completed during construction. However, it was discovered that the geological conditions of the opposite hillside were not ideal, requiring extensive slope excavation and support work. Furthermore, the construction schedule was extremely tight (the exhaust tunnel needed to be excavated from the ground, so the slope excavation and support had to be completed before the exhaust tunnel could be excavated; without the exhaust tunnel, the underground plant would never have a complete ventilation system, resulting in poor air quality). Adopting the original plan would not only require more manpower and resources but also significantly shorten the construction period. Therefore, after comprehensive research, the surface exhaust fan room was directly located within the tunnel to be excavated. This had a positive impact on the project construction, saving at least six months of construction time and reducing investment by more than 4.3 million yuan.

[0094] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A design method for a semi-underground tunnel-type main exhaust fan room system of a pumped storage power station, wherein the structure of the semi-underground tunnel-type main exhaust fan room system of the pumped storage power station is as follows: an exhaust shaft (2) is set at the top of one end of the underground powerhouse (1), an exhaust horizontal tunnel (3) is set at the top of the exhaust shaft (2), the exhaust horizontal tunnel (3) is connected to the fan room tunnel (4), one end of the fan room tunnel (4) is adjacent to the hillside road (10), the fan room tunnel (4) is divided into an air intake equalization chamber (4-1), a main exhaust fan room (4-2), an electrical equipment room (4-3), an operation and maintenance corridor (4-4), and an exhaust duct (4- 5) The tunnel-road connection transition section (4-6) and the tunnel exhaust section (4-7) are equipped with fans and suction and exhaust pipes in the main exhaust fan room (4-2). The suction pressure equalization chamber (4-1) is directly vertically connected to the exhaust tunnel (3), so that the exhaust tunnel (3) and the machine room tunnel (4) form a "T" shape structure. The fans and suction and exhaust pipes consist of an exhaust fan (8-1), a suction pipe (8-2), and an exhaust pipe (8-3). The exhaust fan (8-1) is of the horizontal inlet and upward outlet type, and the suction pipe (8-2) is set in a direction parallel to the ground and is connected to the suction of the exhaust fan (8-1). The exhaust pipe (8-3) is set vertically to the ground and connected to the exhaust end of the exhaust fan (8-1); the machine room tunnel (4) is arranged in the horizontal direction as follows: tunnel exhaust section (4-7), main exhaust fan room (4-2), air intake equalization chamber (4-1) and exhaust channel (4-5), electrical equipment room (4-3) and maintenance corridor (4-4), tunnel and road connection transition section (4-6). The main exhaust fan room (4-2), air intake equalization chamber (4-1) and exhaust channel (4-5) are at the same cross section of the machine room tunnel (4). 5) Above the main exhaust fan room (4-2), the suction equalization chamber (4-1) is on one side of the exhaust duct (4-5) and the main exhaust fan room (4-2). The electrical equipment room (4-3) and the maintenance corridor (4-4) are on the same cross section of the machine room tunnel (4). The electrical equipment room (4-3) and the maintenance corridor (4-4) are arranged adjacent to each other on the left and right. The tunnel and road connection transition section (4-6) is connected to the hillside road (10). The tunnel exhaust section (4-7) leads directly to the outside. Louvered air vents (9) are installed on the wall at the end of the exhaust duct (4-5). The characteristic is that... The design methodology includes the following steps: Step 1: In the area directly above the underground plant (1), along the hillside road (10), find a location that meets the conditions for excavation to form the machine room tunnel (4); Step 2: Based on the terrain conditions, measure and calculate the total length L0 of the tunnel (4) that runs from one side of the hillside road (10) to the other side in the mountain (11); Step 3: Determine the total exhaust volume Q of the underground plant (1): Calculate the minimum ventilation volume Q1 to meet the air exchange rate requirement, calculate the minimum ventilation volume Q2 required to discharge the heat generated by the electromechanical equipment in the underground plant (1), calculate the minimum ventilation volume Q3 for areas with emergency exhaust requirements, calculate the minimum smoke exhaust volume Q4 in the smoke control system design, and take the maximum value among Q1, Q2, Q3 and Q4 for the total exhaust volume Q of the underground plant (1); Step 4: Determine the dimensions of a single exhaust fan (8-1) under different combinations of fan numbers based on the total exhaust volume Q value calculated in Step 3: If 3 exhaust fans (8-1) are selected, the exhaust volume of a single exhaust fan (8-1) is Q / 3. Using this exhaust volume and referring to the fan specifications provided by the fan manufacturer, determine the specific dimensions of the corresponding fan model under this exhaust volume condition: Length × Width × Height = l 1× d 1× h 1; Using this method, calculate the specific dimensions of a single exhaust fan (8-1) under the condition of selecting 4 exhaust fans (8-1): Length × Width × Height = l 2× d 2× h 2. Under the condition of selecting 5 exhaust fans (8-1), the specific dimensions of a single exhaust fan (8-1) are: Length × Width × Height = l 3× d 3× h 3. Under the condition of selecting 6 exhaust fans (8-1), the specific dimensions of a single exhaust fan (8-1) are: Length × Width × Height = l 4× d 4× h 4; Step 5: Determine the length of the total exhaust fan room (4-2) for different combinations of exhaust fan (8-1) quantities, the maximum length of the electrical equipment room (4-3) corresponding to the total power consumption of the exhaust fans (8-1) under the corresponding operating conditions, and the sum of the two, L. a To facilitate the installation, operation, and maintenance of the fans, the minimum distance between the fans and the side walls, as well as between adjacent fans, is 1.5 meters. The length L1 of the main exhaust fan room (4-2) corresponding to the 3 exhaust fans (8-1) is L1=3. l 1 + 4 × 1.5m; The maximum length of the electrical equipment room (4-3) corresponding to the total power consumption of 3 exhaust fans (8-1) is denoted as L. 11 At this point, the length L1 of the main exhaust fan room (4-2) and the maximum length L of the electrical equipment room (4-3) are equal. 11 Sum of: L a1 = L1+ L 11 ; The length L2 of the main exhaust fan room (4-2) corresponding to the 4 exhaust fans (8-1) is L2=3. l 2 + 5 × 1.5m; The maximum length of the electrical equipment room (4-3) corresponding to the total power consumption of 4 exhaust fans (8-1) is denoted as L. 22 At this point, the length L2 of the main exhaust fan room (4-2) and the maximum length L of the electrical equipment room (4-3) are equal. 22 Sum of: L a2 = L2+ L 22 ; The length L3 of the main exhaust fan room (4-2) corresponding to the 5 exhaust fans (8-1) is L3=3. l 3 + 6 × 1.5m; The maximum length of the electrical equipment room (4-3) corresponding to the total power consumption of 5 exhaust fans (8-1) is denoted as L. 33 At this point, the length L3 of the main exhaust fan room (4-2) and the maximum length L of the electrical equipment room (4-3) are equal. 33 Sum of: L a3 = L3+ L 33 ; The total length L4 of the main exhaust fan room (4-2) corresponding to the 6 exhaust fans (8-1) is L4=3. l 4 + 7 × 1.5m; The maximum length of the electrical equipment room (4-3) corresponding to the total power consumption of 6 exhaust fans (8-1) is denoted as L. 44 At this point, the length L4 of the main exhaust fan room (4-2) and the maximum length L of the electrical equipment room (4-3) are equal. 44 Sum of: L a4 = L4+ L 44 ; Step 6: Determine the minimum total length L of the tunnel-road connection transition section (4-6) and the tunnel ventilation section (4-7). b Based on the fact that the distance between the top of the tunnel ventilation section (4-7) and the outer slope is not less than 3 meters, measure and calculate L. b1 Based on the premise that the distance between the top of the tunnel-road connection transition section (4-6) and the outer hillside is not less than 10 meters, L is measured and calculated. b2 Thus, L can be obtained. b = L b1 +L b2 ; Step 7: Determine the number of exhaust fans (8-1) to be installed; compare L under different combinations of exhaust fan (8-1) quantities. a + L b And the size of L0; Under the premise that the length L0 of the machine room tunnel (4) meets the requirements, the excavation of the cross section should be minimized as much as possible, that is, the number of exhaust fans (8-1) should be increased and the width and height of a single exhaust fan (8-1) should be reduced. The following conclusions are drawn: If L a4 + L b If L0 is less than or equal to L0, then select 6 exhaust fans (8-1). If L a4 + L b > L0≥ L a3 + L b If so, select 5 exhaust fans (8-1); If L a3 + L b > L0≥ L a2 + L b If so, select 4 exhaust fans (8-1); If L a2 + L b > L0≥ L a1 + L b If so, select 3 exhaust fans (8-1); L0< L a1 + L b If the length of L0 is insufficient, the machine room tunnel (4) needs to be replanned and selected. Step 8: Calculate the minimum width D of the main exhaust fan room (4-2) a and minimum height H a Based on the comparison results in step 7, determine the number of exhaust fans (8-1) to be installed, and determine the dimensions of a single exhaust fan (8-1): that is, length × width × height = l p × d p × h p Based on the air volume of a single exhaust fan (8-1) and the wind speed conditions specified in the standard, determine the cross-sectional dimensions of the suction pipe (8-2) and the exhaust pipe (8-3). The lengths of the suction pipe (8-2) and the exhaust pipe (8-3) meet the minimum distance requirements for the installation of the air valve. The minimum installation length of the suction pipe (8-2) is denoted as... l g The minimum installation length of the exhaust duct (8-3) is denoted as h g Find the minimum height H of the main exhaust fan room. a H a = h p + h g To meet the transportation and maintenance requirements of the innermost exhaust fan (8-1) in the main exhaust fan room (4-2), the width of the maintenance space within the main exhaust fan room (4-2) shall not be less than [a certain value]. d p Given +1.0m, calculate the minimum width D of the main exhaust fan room (4-2). a D a = d p + h g + d p + 1.0m; Step 9: Minimum width D0 of computer room tunnel (4): The width of the air intake equalization chamber (4-1) shall not be less than 2m, considering the partition wall with a thickness of 0.2m, combined with the minimum width D of the main exhaust fan room (4-2) calculated in Step 8. a Calculate D0 = D a + 2m +0.2m Step 10: Calculate the height H of the exhaust duct (4-5) b The total area of ​​the louvered air vent (9) shall be no less than 0.6 times the cross-sectional area of ​​the exhaust duct (4-5), and the maximum wind speed of the exhaust vent shall be determined according to the specifications. v max1 And the total exhaust volume Q calculated above, calculate the minimum effective area F of the louvered air outlet (9). min1 = Q / v max1 Then, use the following formula to calculate the height H of the exhaust duct (4-5). b : F min1 = H b × D a × μ 1× μ 2× μ 3 in, μ 1 is the ratio of the total area of ​​the louvered air vent (9) to the cross-sectional area of ​​the exhaust channel (4-5), with a value of 0.6; μ 2 is the effective exhaust area coefficient of the louvered air vent (9) under the condition of considering the obstruction factor, and the value is 0.8; μ 3 is the check coefficient for the non-rectangular cross-section of the exhaust duct (4-5), with a value of 0.9; Step 11: Determine the minimum height H0 of the machine room tunnel (4): Considering a 0.2m thick concrete partition slab, H0 = H a + H b +0.2m; Step 12: Determine the cross-sectional excavation dimensions of the machine room tunnel (4); combining the D0 value calculated in step 9 and the H0 value calculated in step 11, considering the lining after excavation and the minimum value calculation method of the above calculation process, the height and width of the machine room tunnel (4) are excavated according to 1.2 times H0 and 1.2 times D0 respectively.

2. The design method for the tunnel-type semi-underground main exhaust fan room system of a pumped storage power station according to claim 1, characterized in that, The outlet section of the exhaust tunnel (3) is located in the middle of the air intake equalization chamber (4-1).

3. The design method for the tunnel-type semi-underground main exhaust fan room system of a pumped storage power station according to claim 1, characterized in that, The ventilation tunnel (3) is either straight or curved.

4. The design method for the tunnel-type semi-underground main exhaust fan room system of a pumped storage power station according to claim 1, characterized in that, The bottom of the ventilation tunnel (3) is flush with the bottom of the machine room tunnel (4).

5. The design method for the tunnel-type semi-underground main exhaust fan room system of a pumped storage power station according to claim 1, characterized in that, The width of the suction equalization chamber (4-1) shall not be less than 2 meters; the number of exhaust fans (8-1) shall be 3-6.

6. The design method for the tunnel-type semi-underground main exhaust fan room system of a pumped storage power station according to claim 1, characterized in that, The cross-section of the machine room tunnel (4) is made into a "horseshoe" shape.

Images