Design method of interface opening of railway station elevated waiting hall based on natural ventilation

Abstract

This invention provides a design method for interface openings in elevated waiting halls of railway stations based on natural ventilation. The method includes: extracting multiple spatial patterns of the elevated waiting hall; constructing a natural ventilation simulation model using computational fluid dynamics; calculating the effective area ratio of natural ventilation in the simulation model; sorting the calculated effective area ratios in descending order; and determining the optimal opening design scheme for the elevated waiting hall under two, three, or four opening type combinations based on the sorting results. This invention reveals a synergistic mechanism for natural ventilation in elevated waiting hall interface openings, ensuring that good natural ventilation effectively improves indoor air quality and enhances passenger thermal comfort while significantly reducing mechanical ventilation energy consumption.

Description

Technical Field

[0001] This invention relates to the technical field of interface opening design for elevated waiting halls in railway stations, and more specifically, to a design method for interface openings in elevated waiting halls in railway stations based on natural ventilation. Background Technology

[0002] During seasons with suitable climates, well-organized natural ventilation can effectively improve indoor air quality, enhance thermal comfort, and reduce building energy consumption. Elevated waiting halls in railway stations are densely populated, generating a large amount of metabolic waste gas, making mechanical ventilation extremely energy-intensive and highlighting the importance of natural ventilation. In recent years, many newly constructed elevated waiting halls in railway stations typically utilize large, open spaces, making it difficult to optimize natural ventilation through geometric adjustments. Therefore, the key issues in the natural ventilation design of elevated waiting halls in railway stations lie in rationally designing interface openings, scientifically matching the combination of air inlets and outlets, effectively organizing the ventilation paths between air inlets and outlets, and synergistically utilizing thermal pressure ventilation, wind pressure ventilation, and their coupling effects.

[0003] Therefore, we urgently need to develop a new design method for the interface opening of elevated waiting halls in railway stations. Summary of the Invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art or related art.

[0005] Therefore, the purpose of this invention is to propose a design method for the interface opening of the elevated waiting hall of a railway station based on natural ventilation.

[0006] To achieve the above objectives, the present invention provides a design method for the interface opening of an elevated waiting hall in a railway station based on natural ventilation. The elevated waiting hall is a rectangular structure, with its two short sides connected to corresponding entrance spaces. The entrance spaces are located on both sides of the railway line. The elevated waiting hall is situated above the railway station platform. Various waiting areas and passenger passageways are arranged within the elevated waiting hall. Other ancillary facilities, besides the waiting areas and passenger passageways, are arranged inside the elevated waiting hall or on the two long sides of its exterior walls. The elevated waiting hall has an axial spatial characteristic. The elevated waiting hall is characterized by... The longitudinal natural ventilation of the waiting hall is limited by the entrance space, while the lateral natural ventilation of the elevated waiting hall of the railway station is related to the layout of other ancillary facilities. The design method for the interface opening of the elevated waiting hall of the railway station based on natural ventilation includes: Step S1: Extracting multiple spatial patterns of the elevated waiting hall of the railway station; wherein, the multiple spatial patterns include: an unobstructed side interface pattern, a partially obstructed upper side interface pattern, a partially obstructed lower side interface pattern, and a fully obstructed side interface pattern; the unobstructed side interface pattern involves dividing the outer wall of the elevated waiting hall of the railway station vertically from bottom to top into a first layer and a second layer; the layout of other ancillary facilities... Inside the elevated waiting hall of a railway station; the other ancillary facilities divide the elevated waiting hall into multiple sections; the side windows are located on the first and / or second floors; the elevated waiting hall is naturally ventilated through the side windows on the exterior walls; the upper semi-obstruction mode of the side interface is as follows: the exterior walls of the elevated waiting hall are vertically divided into a first and a second floor from bottom to top; the other ancillary facilities are located on the second floor; the side windows are located on the first floor; the elevated waiting hall is naturally ventilated through the side windows; the lower semi-obstruction mode of the side interface is as follows: the exterior walls of the elevated waiting hall are vertically divided into a first and a second floor from bottom to top; the other ancillary facilities are located on the second floor; the side windows are located on the first floor; the elevated waiting hall is naturally ventilated through the side windows; the lower semi-obstruction mode of the side interface is as follows: the exterior walls of the elevated waiting hall are vertically divided into a first and a second floor from bottom to top. The space is divided into a first floor and a second floor; the other ancillary facilities are arranged on the first floor; the side windows are arranged on the second floor; the elevated waiting hall of the railway station is naturally ventilated through the side windows; the side interface is fully covered in the following way: the other ancillary facilities are arranged along the vertical direction of the outer wall of the elevated waiting hall of the railway station; no side windows are opened on the outer wall of the elevated waiting hall of the railway station; and the side windows opened on the first floor are low side windows; the side windows opened on the second floor are high side windows; Step S2: Based on the above multiple spatial modes, the numerical simulation method of computational fluid dynamics is selected to build a natural ventilation simulation experimental model of the elevated waiting hall of the railway station;The opening types in the natural ventilation simulation experimental model include one or a combination of the following: ground opening A, roof opening B, low side window on the windward side C, high side window on the windward side D, low side window on the leeward side E, and high side window on the leeward side F; the number of openings corresponding to ground opening A, roof opening B, low side window on the windward side C, high side window on the windward side D, low side window on the leeward side E, and high side window on the leeward side F is the same. The horizontal distance between the ground opening A and the windward side of the outer wall of the elevated waiting hall of the railway station is L1; the horizontal distance between the roof opening B and the windward side of the outer wall of the elevated waiting hall of the railway station is L2; ​​the height of the windward low-side window C from the ground of the elevated waiting hall of the railway station is H1; the height of the windward high-side window D from the ground of the elevated waiting hall of the railway station is H2; the height of the leeward low-side window E from the ground of the elevated waiting hall of the railway station is H3; the height of the leeward high-side window F from the ground of the elevated waiting hall of the railway station is H4; and the ground opening A is expressed as A. L1 The roof opening B is expressed as B. L2 The windward low-side window C is expressed in the form of C. H1 The windward high side window D is expressed in the form of D. H2 The leeward low-side window E is expressed as E H3 The leeward side window F is expressed as F H4 Step S3: Calculate the effective area ratio of natural ventilation in the natural ventilation simulation experiment model; Step S4: Sort the calculation results of the effective area ratio of natural ventilation in descending order; Step S5: Based on the sorting results of the effective area ratio of natural ventilation, derive the optimal opening design schemes for the elevated waiting hall of the railway station under two opening type combinations, three opening type combinations, and four opening type combinations, so as to achieve the best natural ventilation effect for the elevated waiting hall of the railway station under two opening type combinations, three opening type combinations, and four opening type combinations, respectively.

[0007] Preferably, in step S2, the roof of the elevated waiting hall of the railway station corresponding to the natural ventilation simulation experimental model is a flat roof, and the dimensions of the elevated waiting hall of the railway station are length... Meters, width meters, height Meters; The ground opening A, roof opening B, windward low side window C, windward high side window D, leeward low side window E, and leeward high side window F are all square in shape; The area of ​​each individual opening corresponding to the ground opening A, roof opening B, windward low side window C, windward high side window D, leeward low side window E, and leeward high side window F is... square meters; , , and All are positive numbers.

[0008] Preferably, It is 200; It is 100; It is 20; =1; It is 14.

[0009] Preferably, in step S2, the values ​​of L1 and L2 are both in the range of 10-90 m, and the interval between the values ​​of L1 and L2 is 10 m; the values ​​of H1 and H3 are both in the range of 1-9 m, the values ​​of H2 and H4 are both in the range of 10-18 m, and the interval between the values ​​of H1, H3, H2 and H4 is 1 m.

[0010] Preferably, in step S3, the effective area ratio of natural ventilation is the ratio of the effective area of ​​natural ventilation in the area where the height of passengers in the elevated waiting hall of the railway station is 1.5m to the floor area of ​​the elevated waiting hall of the railway station; the effective area of ​​natural ventilation is the area of ​​the area where the wind speed is higher than 0.1m / s in the area where the height of passengers in the elevated waiting hall of the railway station is 1.5m.

[0011] Preferably, step S3 specifically involves: calculating the effective area ratio of natural ventilation in the natural ventilation simulation experiment model using a wind speed cloud map of the elevated waiting hall of a railway station at a height of 1.5m.

[0012] The beneficial effects of this invention are:

[0013] The present invention provides a design method for interface openings in elevated waiting halls of railway stations based on natural ventilation. This method extracts four typical spatial patterns of elevated waiting halls in railway stations based on research, and selects computational fluid dynamics (CFD) as the design method. Using the CFD (Conventional Dynamics) numerical simulation method, a natural ventilation simulation model of an elevated waiting hall in a railway station was constructed. The model used ground openings (A), roof openings (B), low side windows (C), high side windows (D), low side windows (E), and high side windows (F) as interface opening variables. Two opening combinations and their optimal solutions, along with three and four opening combinations, were sequentially input into the parameterized natural ventilation simulation model, outputting the effective area ratio of natural ventilation in the elevated waiting hall. Through numerical analysis, the synergistic effect of natural ventilation through interface opening combinations was proposed, and optimal solutions for two, three, and four opening combinations under different spatial modes were derived. This revealed the synergistic mechanism of natural ventilation through interface openings in elevated waiting halls, characterized by wind pressure dominance, thermal pressure assistance, and path regulation. This ensures that the elevated waiting hall effectively improves indoor air quality and enhances passenger thermal comfort through good natural ventilation, while significantly reducing mechanical ventilation energy consumption.

[0014] Additional aspects and advantages of the invention will become apparent from the description which follows, or may be learned by practice of the invention. Attached Figure Description

[0015] Figure 1 A flowchart illustrating a design method for an interface opening in an elevated waiting hall of a railway station based on natural ventilation, according to an embodiment of the present invention, is shown.

[0016] Figure 2 A schematic diagram of the spatial structure of an elevated waiting hall in a railway station according to an embodiment of the present invention is shown;

[0017] Figure 3a A schematic diagram of the unobstructed side interface of an elevated waiting hall in a railway station according to an embodiment of the present invention is shown.

[0018] Figure 3b A schematic diagram of the upper semi-obstructed side interface of an elevated waiting hall in a railway station according to an embodiment of the present invention is shown.

[0019] Figure 3c A schematic diagram of the lower half-obstruction mode of the side interface of an elevated waiting hall in a railway station according to an embodiment of the present invention is shown.

[0020] Figure 3d This invention illustrates a structural schematic diagram of a fully obscured side interface of an elevated waiting hall in a railway station according to an embodiment of the present invention.

[0021] Figure 4 A schematic diagram of a fluid computational domain according to an embodiment of the present invention is shown;

[0022] Figure 5 The diagram illustrates the opening variable settings for ground opening A, roof opening B, windward low side window C, windward high side window D, leeward low side window E, and leeward high side window F, respectively, according to an embodiment of the present invention.

[0023] Figure 6 A schematic diagram of the effective area ratio of natural ventilation for two opening combinations according to an embodiment of the present invention is shown.

[0024] Figure 7 A schematic diagram showing the effective area ratio of natural ventilation in a CE opening combination according to an embodiment of the present invention is provided.

[0025] Figure 8 A schematic diagram showing the effective area ratio of natural ventilation in a DE opening combination according to an embodiment of the present invention is provided.

[0026] Figure 9 A schematic diagram showing the effective area ratio of natural ventilation in a CF opening combination according to an embodiment of the present invention is provided.

[0027] Figure 10 A schematic diagram showing the effective area ratio of natural ventilation in a DF opening combination according to an embodiment of the present invention is provided.

[0028] Figure 11 A schematic diagram showing the effective area ratio of natural ventilation in a CA opening combination according to an embodiment of the present invention is provided.

[0029] Figure 12 A schematic diagram showing the effective area ratio of natural ventilation in a DA opening combination according to an embodiment of the present invention is provided.

[0030] Figure 13 A schematic diagram showing the effective area ratio of natural ventilation in a CB opening combination according to an embodiment of the present invention is provided.

[0031] Figure 14 A schematic diagram showing the effective area ratio of natural ventilation in a DB opening combination according to an embodiment of the present invention is provided.

[0032] Figure 15 C6B, an embodiment of the present invention, is shown. 90 Vector diagram of natural ventilation section with opening combination;

[0033] Figure 16 A cross-sectional vector diagram of the natural ventilation section of the C6E1 opening combination according to an embodiment of the present invention is shown;

[0034] Figure 17 D illustrates an embodiment of the present invention. 11 A 10 Vector diagram of natural ventilation section with opening combination;

[0035] Figure 18 A preferred operating condition A according to an embodiment of the present invention is shown. 10 B 80 Vector diagram of natural ventilation section with opening combination;

[0036] Figure 19 The optimal operating condition A of one embodiment of the present invention is shown. 50 B 40 Vector diagram of natural ventilation section with opening combination;

[0037] Figure 20 C6B, an embodiment of the present invention, is shown. 90 A and C8B 90 A schematic diagram showing the effective area ratio of natural ventilation in the A-type opening combination;

[0038] Figure 21 C6B, an embodiment of the present invention, is shown. 90 E and C8B 90 A schematic diagram illustrating the effective area ratio of natural ventilation in the E-opening combination;

[0039] Figure 22 C6B, an embodiment of the present invention, is shown. 90 A 60 Vector diagram of natural ventilation section with opening combination;

[0040] Figure 23 A schematic diagram showing the effective area ratio of natural ventilation for the combination of openings C6E1A and C1E1A according to an embodiment of the present invention is provided.

[0041] Figure 24 A schematic diagram showing the effective area ratio of natural ventilation for the combination of openings C6E1B and C1E1B according to an embodiment of the present invention is provided.

[0042] Figure 25 C6E1A, an embodiment of the present invention, is shown. 90 Vector diagram of natural ventilation section with opening combination;

[0043] Figure 26 D illustrates an embodiment of the present invention. 11 A 10 F and D 14 A 10 A schematic diagram illustrating the effective area ratio of natural ventilation in the F-opening combination;

[0044] Figure 27 D illustrates an embodiment of the present invention. 11 A 10 B and D 14 A 10 A schematic diagram illustrating the effective area ratio of natural ventilation in the B-type opening combination;

[0045] Figure 28 D illustrates an embodiment of the present invention. 11 A 10 B 60 Vector diagram of natural ventilation section with opening combination;

[0046] Figure 29 C6B, an embodiment of the present invention, is shown. 90 A 60 A schematic diagram illustrating the effective area ratio of natural ventilation in the E-opening combination;

[0047] Figure 30 C6E1A, an embodiment of the present invention, is shown. 90 A schematic diagram illustrating the effective area ratio of natural ventilation in the B-type opening combination;

[0048] Figure 31 D illustrates an embodiment of the present invention. 11 A 10 B 60A schematic diagram showing the effective area ratio of natural ventilation in the F-opening combination. Detailed Implementation

[0049] To better understand the above-mentioned objects, features, and advantages of the present invention, such as Figures 1 to 31 As shown in the accompanying drawings and specific embodiments, the present invention will be further described in detail below. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0050] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and therefore the scope of protection of the invention is not limited to the specific embodiments disclosed below.

[0051] Figure 1 A flowchart illustrating a design method for the interface opening of an elevated waiting hall in a railway station based on natural ventilation, according to an embodiment of the present invention, is shown. Figure 2 As shown, the elevated waiting hall of the railway station has a rectangular structure, with its two shorter sides connected to corresponding entrance spaces. The entrance spaces are located on both sides of the railway line. The elevated waiting hall is situated above the railway station platform. Various waiting areas and passenger passageways are arranged within the elevated waiting hall. Other ancillary facilities, besides the waiting areas and passenger passageways, are located inside the elevated waiting hall or on the two longer sides of its exterior walls. The elevated waiting hall has an axial spatial characteristic. The longitudinal (longer direction) natural ventilation of the elevated waiting hall is limited by the entrance spaces, while the lateral (shorter direction) natural ventilation is related to the layout of the other ancillary facilities. Figure 1 As shown, this design method includes:

[0052] Step S1: Extract multiple spatial modes of the elevated waiting hall of the railway station; wherein, the multiple spatial modes include: side interface unobstructed mode, upper side interface semi-obstructed mode, lower side interface semi-obstructed mode, and side interface fully obstructed mode.

[0053] The unobstructed side interface mode is as follows: the outer wall of the elevated waiting hall of the railway station is vertically divided into a first layer and a second layer from bottom to top; the other ancillary facilities are arranged inside the elevated waiting hall of the railway station; the other ancillary facilities divide the elevated waiting hall of the railway station into multiple parts; the side windows are opened on the first layer and / or the second layer; the elevated waiting hall of the railway station is naturally ventilated through the side windows opened on the outer wall;

[0054] The upper semi-obstruction mode of the side interface is as follows: the outer wall of the elevated waiting hall of the railway station is divided into a first layer and a second layer vertically from bottom to top; the other ancillary facilities are arranged on the second layer; the side windows are opened on the first layer; the elevated waiting hall of the railway station is naturally ventilated through the side windows.

[0055] The lower semi-obstructed mode of the side interface is as follows: the outer wall of the elevated waiting hall of the railway station is divided into a first layer and a second layer vertically from bottom to top; the other ancillary facilities are arranged on the first layer; the side windows are arranged on the second layer; the elevated waiting hall of the railway station is naturally ventilated through the side windows;

[0056] The side interface full-coverage mode is as follows: the other ancillary facilities are arranged along the vertical direction of the outer wall of the elevated waiting hall of the railway station in a continuous length and height; no side windows are opened on the outer wall of the elevated waiting hall of the railway station; and the side windows opened on the first floor are low side windows; the side windows opened on the second floor are high side windows.

[0057] Step S2: Based on multiple spatial models, a numerical simulation method of computational fluid dynamics is selected to build a natural ventilation simulation experimental model for elevated waiting halls of railway stations; the opening types of the natural ventilation simulation experimental model include one or a combination of the following: ground opening A, roof opening B, low side window on the windward side C, high side window on the windward side D, low side window on the leeward side E, and high side window on the leeward side F.

[0058] The number of openings corresponding to ground opening A, roof opening B, windward low side window C, windward high side window D, leeward low side window E, and leeward high side window F are all... indivual;

[0059] The horizontal distance between the ground opening A and the windward side of the outer wall of the elevated waiting hall of the railway station is L1, and the horizontal distance between the roof opening B and the windward side of the outer wall of the elevated waiting hall of the railway station is L2.

[0060] The windward low-side window C is at a height of H1 from the ground of the elevated waiting hall of the railway station; the windward high-side window D is at a height of H2 from the ground of the elevated waiting hall of the railway station; the leeward low-side window E is at a height of H3 from the ground of the elevated waiting hall of the railway station; and the leeward high-side window F is at a height of H4 from the ground of the elevated waiting hall of the railway station.

[0061] And the ground opening A is expressed as A L1 The roof opening B is expressed as B. L2 The windward low-side window C is expressed in the form of C. H1 The windward high side window D is expressed in the form of D. H2 The leeward low-side window E is expressed as E H3The leeward side window F is expressed as F H4 ;

[0062] Step S3: Calculate the effective area ratio of natural ventilation in the natural ventilation simulation experimental model; specifically, the numerical simulation method of Computational Fluid Dynamics (CFD) is selected to calculate the effective area ratio of natural ventilation in the natural ventilation simulation experimental model.

[0063] Step S4: Sort the calculated results of the effective area ratio of natural ventilation in descending order;

[0064] Step S5: Based on the ranking of the effective area ratio of natural ventilation, the optimal opening design schemes for elevated waiting halls of railway stations under two-opening-type combinations, three-opening-type combinations, and four-opening-type combinations are obtained, so as to achieve the best natural ventilation effect for elevated waiting halls of railway stations under two-opening-type combinations, three-opening-type combinations, and four-opening-type combinations, respectively.

[0065] In this embodiment, the present invention extracts four typical spatial patterns of elevated waiting halls in railway stations based on research, and selects computational fluid dynamics (CFD). Using the CFD (Conventional Dynamics) numerical simulation method, a natural ventilation simulation model for elevated waiting halls in railway stations was constructed. The model used ground openings A, roof openings B, low side windows C, high side windows D, low side windows E, and high side windows F as interface opening variables. Two opening combinations and their optimal combinations (three and four openings) were sequentially input into the parameterized natural ventilation simulation model, correspondingly outputting the effective area ratio of natural ventilation in the elevated waiting hall. Through numerical analysis, the synergistic effect of natural ventilation through interface opening combinations was proposed, and optimal combinations of two, three, and four openings under different spatial modes were derived. This revealed the synergistic mechanism of natural ventilation through interface openings in elevated waiting halls, characterized by wind pressure dominance, thermal pressure assistance, and path control. This ensures that elevated waiting halls in railway stations effectively improve indoor air quality and enhance passenger thermal comfort through good natural ventilation, while significantly reducing mechanical ventilation energy consumption.

[0066] The following specific embodiment will demonstrate the design method of the interface opening of the elevated waiting hall of a railway station based on natural ventilation according to the present invention. The elevated waiting hall of the railway station has a cuboid structure, and its two short sides are respectively connected to the corresponding entrance spaces; the entrance spaces are respectively located on both sides of the railway line; the elevated waiting hall is built above the railway station platform; various waiting areas and passenger passages between the waiting areas are arranged within the elevated waiting hall; other ancillary facilities besides the waiting areas and passenger passages are arranged inside the elevated waiting hall or on the two long sides of its exterior wall; the elevated waiting hall has an axial spatial characteristic; the longitudinal (longer direction is called longitudinal) natural ventilation of the elevated waiting hall is limited by the entrance spaces, and the lateral (shorter direction is called lateral) natural ventilation is related to the layout of the other ancillary facilities; the design method of the interface opening of the elevated waiting hall of a railway station based on natural ventilation is specifically implemented through the following steps:

[0067] Step S1: Extract multiple spatial modes of the elevated waiting hall of the railway station; among which, the multiple spatial modes include: side interface unobstructed mode, upper side interface semi-obstructed mode, lower side interface semi-obstructed mode and side interface fully obstructed mode.

[0068] The unobstructed side facade design involves dividing the exterior wall of the elevated waiting hall of the railway station vertically into a first layer and a second layer from bottom to top; other ancillary facilities are arranged inside the elevated waiting hall; these ancillary facilities divide the elevated waiting hall into multiple parts; the side windows are located on the first layer and / or the second layer; the elevated waiting hall is naturally ventilated through the side windows on the exterior wall. The semi-obstructed upper side facade design involves dividing the exterior wall of the elevated waiting hall vertically into a first layer and a second layer from bottom to top; other ancillary facilities are arranged on the second layer; the side windows are located on the first layer. The elevated waiting hall of the railway station is naturally ventilated through the side windows; the lower part of the side interface is partially obscured as follows: the outer wall of the elevated waiting hall is vertically divided into a first layer and a second layer from bottom to top; the other ancillary facilities are arranged on the first layer; the side windows are arranged on the second layer; the elevated waiting hall of the railway station is naturally ventilated through the side windows; the side interface is fully obscured as follows: the other ancillary facilities are arranged along the entire length and height of the outer wall of the elevated waiting hall; no side windows are opened on the outer wall of the elevated waiting hall; and the side windows opened on the first layer are low side windows; the side windows opened on the second layer are high side windows.

[0069] In step S1, as Figure 2As shown, in the elevated waiting hall mode of railway stations, the station building has entrance halls on both sides of the railway line, and the waiting halls are elevated above the platform level. The waiting halls are mostly single spaces with large spans and high ceilings. The interior of the waiting hall is mainly divided into waiting areas for different train numbers, with passenger passages from the entrance hall to the ticket gates interspersed within. Other ancillary facilities such as shops, restaurants, and restrooms are also centrally located.

[0070] Elevated waiting halls in railway stations typically feature a large, axial space. Longitudinal natural ventilation is limited by the entrance space (i.e., the entrance hall), while lateral natural ventilation is closely related to the layout of other ancillary facilities. Based on the location of these facilities and their impact on natural ventilation, railway station waiting halls can be categorized into four typical spatial patterns. For example... Figure 3a As shown, one category is other ancillary facilities ( Figure 3a The gray blocks (as depicted in the image) are typically single-layered blocks within the large spaces of railway station waiting halls, dividing the waiting hall into multiple sections. The exterior walls can have high and low side windows for natural ventilation, creating an unobstructed side facade. For example... Figure 3b As shown, the second category is other ancillary facilities ( Figure 3b The gray blocks (in the image) are arranged only along the two-story longitudinal exterior wall of the railway station waiting hall, allowing for natural ventilation through low side windows on the first-floor exterior wall, creating a semi-obscured upper side facade; (e.g.) Figure 3c As shown, the third category is other ancillary facilities ( Figure 3c The gray blocks (in the image) are arranged only along the first floor of the longitudinal exterior wall of the railway station waiting hall, allowing for natural ventilation via high side windows on the second floor exterior wall, creating a semi-obscured lower side facade; (e.g.) Figure 3d As shown, the fourth category consists of other ancillary facilities that are set along the longitudinal exterior walls of the railway station waiting hall, which have the greatest impact on the natural ventilation of the railway station waiting hall. Side windows cannot be opened on the longitudinal exterior walls on both sides, resulting in a full occlusion mode of the side interface.

[0071] II. Step S2: Based on multiple spatial models, a numerical simulation method using computational fluid dynamics is selected to construct a natural ventilation simulation experimental model for an elevated waiting hall in a railway station. The opening types in the natural ventilation simulation experimental model include one or a combination of the following: ground opening A, roof opening B, low side window on the windward side C, high side window on the windward side D, low side window on the leeward side E, and high side window on the leeward side F. The number of openings corresponding to ground opening A, roof opening B, low side window on the windward side C, high side window on the windward side D, low side window on the leeward side E, and high side window on the leeward side F is [not specified in the original text]. The horizontal distance between the ground opening A and the windward side of the outer wall of the elevated waiting hall of the railway station is L1; the horizontal distance between the roof opening B and the windward side of the outer wall of the elevated waiting hall of the railway station is L2; ​​the height of the windward low-side window C from the ground of the elevated waiting hall of the railway station is H1; the height of the windward high-side window D from the ground of the elevated waiting hall of the railway station is H2; the height of the leeward low-side window E from the ground of the elevated waiting hall of the railway station is H3; the height of the leeward high-side window F from the ground of the elevated waiting hall of the railway station is H4; and the ground opening A is expressed as A. L1 The roof opening B is expressed as B. L2 The windward low-side window C is expressed in the form of C. H1 The windward high side window D is expressed in the form of D. H2 The leeward low-side window E is expressed as E H3 The leeward side window F is expressed as F H4 ;

[0072] The natural ventilation simulation model corresponds to a flat roof in the elevated waiting hall of a railway station, and the dimensions of the elevated waiting hall are [length missing]. Meters, width meters, height Meters; the ground opening A, roof opening B, windward low side window C, windward high side window D, leeward low side window E, and leeward high side window F are all square in shape; the area of ​​each individual opening corresponding to the ground opening A, roof opening B, windward low side window C, windward high side window D, leeward low side window E, and leeward high side window F is... square meters; It is 200; It is 100; It is 20; =1;

[0073] The number of openings is 14. There are 14 openings for each type: ground opening A, roof opening B, low side window on the windward side C, high side window on the windward side D, low side window on the leeward side E, and high side window on the leeward side F. For example, C6B... 90 There are 14 low-lying side windows (C) facing the wind and 14 roof openings (B). If it includes three types of openings, there are 14 openings of each type. This number of 14 is based on extensive surveys and design specifications for railway stations.

[0074] The values ​​of L1 and L2 are both in the range of 10-90 m, and the interval between the values ​​of L1 and L2 is 10 m; the values ​​of H1 and H3 are both in the range of 1-9 m, the values ​​of H2 and H4 are both in the range of 10-18 m, and the interval between the values ​​of H1, H3, H2 and H4 is 1 m.

[0075] In step S2, a survey and analysis of elevated waiting halls in Chinese railway stations was first conducted. Based on a survey of 67 railway stations in 11 provinces and municipalities in northern my country, there are 59 large railway stations, of which 81.4% are elevated waiting halls. 95.8% of the elevated waiting halls have a rectangular floor plan, with spatial dimensions typically around 200m long, 100m wide, and 20m high. 94.0% of the elevated waiting halls have flat roofs, often with skylights. Regarding side openings in the waiting halls, the "Code for Design of Railway Passenger Station Buildings" and related standards do not explicitly specify the area of ​​natural ventilation openings. Field surveys show that there are generally 1-2 low and high side windows between the ticket gates in the waiting hall, with each opening area between 0.5-0.8 square meters. The "Code for Design of Railway Passenger Station Buildings" requires that large stations with a maximum capacity of ≥8000 people should have 28 ticket gates on both sides. Based on this, the baseline area of ​​the high side windows, low side windows, top windows, and ground openings in the basic experimental model of the elevated waiting hall was set at 1m², with a total of 14 openings evenly distributed on each ticket gate side. Preliminary simulation experiments revealed that, with the same opening area, compared to horizontal and vertical vents, square vents achieve a more uniform indoor airflow distribution, reduce local vortices, and contribute to an overall improvement in the ventilation efficiency of the waiting hall.

[0076] Based on the above survey, statistics, and analysis, a natural ventilation simulation experimental model for elevated waiting halls in railway stations was constructed: the station building and the elevated waiting hall have a rectangular floor plan, the roof of the elevated waiting hall is a flat roof, and the dimensions of the elevated waiting hall are 200m long, 100m wide, and 20m high. The side surfaces can have low and high side windows, the top surface can have skylights, and the bottom surface can have ground-level openings. The openings are square, with an area of ​​1m² per opening, and 14 openings of each type are evenly distributed along the long axis of the waiting hall.

[0077] In step S2, the basic setup for the simulation experiment corresponding to the natural ventilation simulation model of the elevated waiting hall of the railway station is carried out.

[0078] (1) Simulation Experiment Platform: The numerical simulation method of Computational Fluid Dynamics (CFD) was selected. A parameterized experimental model and its external computational domain were established through the Geometry preprocessor. A full hexahedral mesh was established by calling Mesh, and the mesh was gradually refined from the external computational domain to the internal mesh of the waiting hall. Mesh independence verification was performed to ensure that the mesh accuracy of the key areas at the openings met the computational specifications. The mesh was transferred to the solver Fluent, and boundary conditions and simulation settings were set in Fluent, including the temperature and heat transfer coefficient of the enclosure structure, the wind speed and temperature of the air inlet, the return temperature of the air outlet, and the heat generated by the people in the room. Experimental variables were input and assigned values, and the equations were solved iteratively. When the residual of the equation is less than one-thousandth, the simulation results are considered to be closest to the steady state. At this time, the CFD Post postprocessor was called for post-processing to extract the natural ventilation evaluation index of the waiting hall reference surface, which is used to describe and judge the natural ventilation effect of the waiting hall.

[0079] (2) Simulation Experiment Boundary Conditions: ① Setting of the Computational Domain. To avoid flow field distortion due to an excessively small simulation area and unnecessary computational load due to an excessively large simulation area, in accordance with the provisions of the "Standard for Calculation of Green Performance of Civil Buildings" (JGJ / T449-2018), the calculation domain for this simulation experiment is set as follows: the height of the waiting hall is 'a', the vertical distance from the top of the building to the upper boundary of the calculation domain is 6.6a, the horizontal distance from the outer edge of the building on the outflow side to the side boundary of the calculation domain is 13.2a, and the horizontal distance from the outer edge of the building in other directions to the side boundary of the calculation domain is 6.6a (e.g., ...). Figure 4 (As shown). Calculations show that the blockage rate in the incoming flow direction is 2.94%, which meets the requirement of a blockage rate less than 3%. ② Setting of wind boundary conditions. The average wind speed of 3 m / s during the transitional season in Shenyang, a typical cold-region city, is used as the reference wind speed at 10 m above the ground; railway stations are mostly located in urban environments, and the ground roughness index is taken as 0.22. The average air temperature is taken as 22℃, and the kinematic viscosity at one atmosphere is... Reynolds number It belongs to fully turbulent flow, based on the Reynolds-averaged Navier-Stokes equations (RANS) model, and adopts... A Realizable turbulence model was used for CFD simulation. Air was assumed to be an incompressible ideal gas, and the Boussinesq approximation was applied. Temperature-induced changes in airflow density were considered, and a pressure-velocity coupling method was used to solve the steady-state airflow field. ③ Thermal boundary conditions were set. Based on survey and measurement results, the inlet air temperature, the interior wall temperature of the building, and the interior roof temperature were simplified and set to constant values ​​of 22℃, 28℃, and 30℃, respectively. According to the classification of labor intensity in the "Air Conditioning Design Manual," passengers are considered to be engaged in very light physical labor, with a human body heat output of 134W / person at 26℃. The maximum number of people gathered in the waiting hall was calculated to be 10,000, assuming a uniform distribution of personnel.

[0080] In step S2, the variables for the simulation experiment corresponding to the natural ventilation simulation model of the elevated waiting hall of the railway station are set again.

[0081] (1) Independent variables in the simulation experiment: ① Opening variables. This study selected ground opening A, roof opening B, low side window C on the windward side and high side window D on the windward side, low side window E on the leeward side and high side window F on the leeward side as independent variables for the openings of the waiting hall interface. For example Figure 5 As shown, the variables for openings A and B are their horizontal distances from the windward sidewall, L1 and L2 respectively, ranging from 10 to 90 meters with a 10-meter interval. The variables for openings C, D, E, and F are their heights from the ground (the floor of the elevated waiting hall in the railway station), H1, H2, H3, and H4 respectively; C and E range from 1 to 9 meters, and D and F range from 10 to 18 meters with a 1-meter interval. Each opening's independent variable is expressed as a combination of the opening type and the values ​​of H and L, such as A... 30 This indicates a ground opening, 30m horizontally from the windward side, F 12This indicates a high-side window on the leeward side, 12m above the ground. ② Opening combination independent variable. There are three types of opening combinations in the elevated waiting hall: First, two-opening combinations. There are 15 combinations of any two openings on the waiting hall interface. After removing invalid CD and EF combinations on the same interface, 13 combinations of two openings are entered into the simulation experiment: CA, CB, CE, CF, DA, DB, DE, DF, AB, AE, AF, BE, and BF. In the actual simulation experiment, each of these 13 opening combinations is subjected to parametric simulation. Second, three-opening combinations. Any three openings on the waiting hall interface can form 20 combinations. To reduce the workload of the simulation experiment and directly approach the optimal solution, in the actual simulation experiment, based on the optimal combination of two openings under three typical spatial modes—unobstructed side interface, high side semi-obstruction, and low side semi-obstruction—a third opening is introduced as an independent variable for the three-opening combination to explore the impact of the third opening on natural ventilation. Third, four-opening combinations. Any four openings on the interface can form 15 combinations. In the actual simulation experiment, based on the optimal combination of three openings, a fourth opening was introduced as an independent variable for the four-opening combination to explore the impact of the fourth opening on natural ventilation. Independent variables for two or more opening combinations are expressed as a combination of the opening variable and its H and L values, such as C6F. 18 The independent variable represents the combination of openings consisting of a low side window (6m above the ground on the windward side) and a high side window (18m above the ground on the leeward side).

[0082] 3. Step S3: Calculate the effective area ratio of natural ventilation in the natural ventilation simulation experiment model.

[0083] In step S3, the dependent variable is set for the simulation experiment corresponding to the natural ventilation simulation model of the elevated waiting hall of the railway station. Specifically, this specific embodiment mainly addresses the problems of uneven indoor air environment and insufficient effective natural ventilation area in the elevated waiting hall. Therefore, the proportion of effective natural ventilation area at a height of 1.5m is selected as the evaluation index, i.e., the dependent variable of the simulation experiment.

[0084] Among them, the effective area ratio of natural ventilation is the ratio of the ground area that meets the specified wind speed requirements to the area of ​​the waiting hall. At present, there are no clear regulations on the wind speed limit for natural ventilation in railway station buildings. Among the relevant domestic and foreign standards, ISO7730 specifies that the summer comfortable wind speed is 0.1~0.3m / s, ASHRAE55-2017 specifies that the minimum indoor healthy wind speed is 0.15m / s, WELL requires that the instantaneous wind speed in the work area be ≤0.3m / s, the "Code for Design of Heating, Ventilation and Air Conditioning of Civil Buildings" (GB 50736-2012) specifies that the wind speed should not be greater than 0.5m / s under the cooling condition in the short-stay area

[11] , the "Standard for Evaluation of Indoor Thermal and Humid Environment of Civil Buildings" (GB / T 50785-2012) requires that the minimum wind speed in the space without artificial cold and heat sources be 0.1m / s.

[0085] Based on the above standards, the effective wind speed for natural ventilation in the waiting hall's activity area is set to be above 0.1 m / s to ensure a balance between ventilation effectiveness and human comfort. After simulation experiments, CFD-Post was used for post-processing to export a wind speed cloud map of the waiting hall at a height of 1.5 m. Areas with wind speeds above 0.1 m / s are considered the effective natural ventilation areas. Image analysis software was used to statistically analyze the percentage of areas with wind speeds above 0.1 m / s, representing the percentage of the effective natural ventilation area.

[0086] IV. Step S4: Sort the calculated results of the effective area ratio of natural ventilation in descending order.

[0087] 5. Step S5: Based on the ranking of the effective area ratio of natural ventilation, the optimal opening design schemes for elevated waiting halls of railway stations under two-opening-type combinations, three-opening-type combinations, and four-opening-type combinations are obtained, so as to achieve the best natural ventilation effect for elevated waiting halls of railway stations under two-opening-type combinations, three-opening-type combinations, and four-opening-type combinations, respectively.

[0088] In steps S4 and S5 of this specific embodiment, the synergistic effect of natural ventilation on the interface opening combination of the elevated waiting hall of the railway station is first studied. Specifically, there are 13 sets of independent variables for the two opening combinations, namely CA, CB, CE, CF, DA, DB, DE, DF, AB, AE, AF, BE, and BF combinations. In the simulation experiment, except for the AB opening combination, each opening combination had 9 values ​​for the windward opening and 3 values ​​for the leeward opening. Specifically, for the CB, CF, CE, CA opening combination, C was set to 1-9m; for the DB, DF, DE, DA opening combination, D was set to 10-18m; and for the AF, AE, BF, BE opening combination, A and B were both set to 10-90m. The other opening variable had three limits: low, medium, and high. Each opening combination had 27 sets of input experimental data and 27 sets of derived data on the effective area ratio of natural ventilation, totaling 324 sets of experimental data. For the AB opening combination, the two openings each had values ​​ranging from 10-90m, resulting in 81 sets of input experimental data and 81 sets of derived data on the effective area ratio of natural ventilation. A total of 405 simulation experiments were conducted, arranged from highest to lowest according to the optimal value of the effective area ratio of natural ventilation. Figure 6 As shown. The synergistic effect of natural ventilation in the combination of openings at the interface of elevated waiting halls in railway stations is further subdivided as follows:

[0089] (1) Correlation effect between opening combination and natural ventilation: In terms of overall natural ventilation effect, the effective area ratio of natural ventilation for the 13 opening combinations is distributed at 2.9% (B 90 E9) -87.0% (C6B) 90The highest value was between 45.6% (B) and 45.6%. 10 F 10 -87.0% (C6B) 90 The lowest value is between 2.9% (B) and 2.9%. 90 The median value ranged from 10.2% (AF) to 68.6% (CB), with the highest, median, and lowest values ​​all showing significant variations. This indicates a significant correlation between opening combinations and natural ventilation (as shown in Table 1).

[0090] Table 1. Percentage of effective natural ventilation area for the combination of two openings (%)

[0091]

[0092] (2) Classification effect of natural ventilation of opening combination: From the natural ventilation effect of different types of opening combination, the two opening combinations CB, CE, CF and CA with low side window C on the windward side have the highest effective area ratio of natural ventilation and the ratio is concentrated in the high value area; the opening combination AB with ground opening A and roof opening B has the second highest effective area ratio of natural ventilation and the ratio is concentrated in the medium to high value area; the two opening combinations DA, DB, DF and DE with high side window D on the windward side have the second highest effective area ratio of natural ventilation and the ratio is evenly distributed; the opening combination BE, AF, AE and BF with ground opening A, roof opening B and low side window E and high side window F on the leeward side have the lowest effective area ratio of natural ventilation and the ratio is concentrated in the low value area. Therefore, it can be concluded that the combination of openings involving the low side window C on the windward side is the preferred option for natural ventilation of the waiting hall, the combination of ground opening A and roof opening B is the second preferred option, the combination of openings involving the high side window D on the windward side is an optional option, and the combination of ground opening A, roof opening B and leeward openings E and F is a non-option.

[0093] (3) Positional Effect of Natural Ventilation in Opening Combinations: The relative positions of the air inlets and outlets significantly impact the natural ventilation of the waiting hall. Even the preferred options CB, CE, CF, and CA exhibit a low effective area ratio for natural ventilation, lower than the optimal values ​​for the non-preferred options BE, AF, AE|, and BF. The fitting curves from the simulation experiments of CE, DE, CF, DF, CA, DA, CB, and DB (e.g.) Figures 7 to 14 As shown in the figure, the effective area of ​​natural ventilation is significantly affected by the values ​​of C and D, and only slightly affected by the values ​​of E, F, A, and B, exhibiting a regular double-peak wave curve. Specifically, when the C value is 6m for low side windows, the proportion of effective natural ventilation area is the highest; when the D value is 10m or 11m for high side windows, the proportion is second highest. Natural ventilation is most effective when the C value is close to the ground level, and relatively poor when the C value is 7-8m; the natural ventilation effect is worst when the D value is close to the roof.

[0094] In steps S4 and S5 of this specific embodiment, the next step is to study the optimal natural ventilation scheme and its mechanism for the combination of two openings on the interface of the elevated waiting hall of the railway station. The specific research content is detailed below:

[0095] (1) Unobstructed side openings in the waiting hall: The side openings CDEF, ground opening A, and roof opening B in the waiting hall are all unrestricted. Among all 13 types of opening combinations and 405 sets of experimental data, the CB combination is relatively better, and the optimal opening combination is C6B. 90 That is, the value of the low side window C on the windward side is 6m and the value of the roof opening B is 90m, and the effective area of ​​natural ventilation accounts for 87.0%.

[0096] Natural ventilation mechanism: Under wind pressure-dominated mode, the horizontal jet of air entering through the low side window C6 on the windward side descends through the area where people are active and reaches the side wall on the leeward side; no obvious vortex is formed at the ground corners on the windward and leeward sides, the airflow is weakly obstructed, and the flow velocity does not change significantly; the airflow is heated as it flows across the ground, and is strengthened by the vertical thermal pressure gradient at the side wall on the leeward side, rising to the roof opening B. 90 Outflow (e.g.) Figure 15 (As shown).

[0097] If the value of C decreases, ground friction resistance and corner vortex effects intensify, while the lateral jet effect weakens. If the value of C increases, the area covered by the descending airflow to the ground decreases, and the effective area ratio of natural ventilation decreases accordingly. If the value of B decreases, the vortex at the corner of the leeward roof will weaken the effect of the thermal pressure gradient. Compared to C6B 90 In contrast, the CA opening combination, with both the air inlet and outlet located at the bottom, is prone to airflow short-circuiting; while the CE opening combination has a shorter airflow path, it lacks the effect of a thermal pressure gradient, resulting in weaker ventilation compared to the C6B. 90 The thermal pressure gradient effect of the CF open-end combination is also weaker than that of C6B. 90 .

[0098] Overall C6B 90 By combining openings and selecting appropriate values, the horizontal wind pressure lateral jet and the vertical thermal pressure gradient are superimposed in the same direction, achieving optimal natural ventilation.

[0099] (2) Semi-obstructed upper side of the waiting hall: Low side windows C on the windward side, low side windows E on the leeward side, ground opening A, and roof opening B can be opened. As explained in Mode 1, CB provides the best natural ventilation among all opening combinations, so this mode will not be discussed further. Comparing the CA and CE opening combinations, the CE combination is relatively better, and the optimal opening combination is C6E1, that is, the value of the high and low windows C on the windward side is 6m, and the value of the low side windows E on the leeward side is 1m, with an effective ventilation area of ​​85.5%.

[0100] Natural ventilation mechanism: Under wind pressure-dominated mode, the horizontal jet of air entering through the low-side window C6 on the windward side passes through the area where people are active; no obvious vortex is formed at the ground corner on the windward side, the airflow is weakly obstructed, and the flow velocity does not change significantly; the airflow exits through the opening E1 on the leeward side, with the shortest airflow path and the weakest wind pressure attenuation; the airflow completely covers the area where people are active, and natural ventilation is most effective (e.g., Figure 16 (As shown).

[0101] If the value of E increases until C6F 18 The thermal pressure effect will be enhanced, and vortex phenomena will also appear at the corner of the ground on the leeward side. The two interfere with each other and do not improve the natural ventilation effect. Compared with the C6E1 opening combination, the CA opening combination is more likely to cause airflow short circuit and cover a smaller area of ​​people, resulting in a relatively poor natural ventilation effect.

[0102] Overall, the combination and reasonable value of the C6E1 openings ensure that the horizontal wind pressure lateral jet and the shortest airflow path are superimposed in the same direction, while avoiding the interference of corner vortices, resulting in the highest airflow coverage efficiency and the optimal natural ventilation effect.

[0103] (3) Semi-obstructed lower side of the waiting hall: High side windows D on the windward side, high side windows F on the leeward side, ground opening A, and roof opening B can be opened. Among the three combinations of DB, DF, and DA, combination DA is relatively better, and the optimal opening combination is D. 11 A 10 That is, the value of the high side window D on the windward side is 11m and the value of the ground opening A is 10m, with the effective ventilation area accounting for 78.1%.

[0104] Natural ventilation mechanism: In wind pressure-dominated mode, the high side window D on the windward side 11 The horizontal jet of air enters the leeward sidewall. At the two roof corners on both the windward and leeward sides, no significant vortex forms, the airflow is only weakly obstructed, and the velocity remains relatively unchanged. However, due to the thermal pressure gradient at the leeward sidewall, the airflow is strengthened, sinks to the ground, and flows back to the A10 opening, passing through most of the waiting hall floor. This significantly increases the effective area of ​​natural ventilation (e.g., ...). Figure 17 (As shown).

[0105] If the value of D increases, the corner vortex and roof friction resistance on the windward side of the roof will be strengthened, weakening the lateral jet. If the value of A increases, the area of ​​the return airflow across the ground will decrease, and the effective area of ​​natural ventilation will decrease accordingly. Compared with the DA opening combination, the inlet and outlet of the DB and DF opening combinations are located at the top, which can easily cause airflow short-circuiting, making it difficult to penetrate into the lower space, resulting in poor ventilation.

[0106] Overall, D 11 A 10The combination of openings and their reasonable values ​​allow the horizontal wind pressure lateral jet and the vertical thermal pressure gradient to superimpose in the same direction, while avoiding the interference of corner vortices, extending the ground airflow, and achieving the optimal natural ventilation effect.

[0107] (4) Fully Enclosed Side Waiting Hall Mode: Normally, in a fully enclosed waiting hall, only skylights can be opened. CFD simulations show that the effective area for natural ventilation is only 11.27%, severely limiting ventilation. Adding a ground opening A, which forms a vertical ventilation path with the roof opening B, can significantly improve the natural ventilation effect of the waiting hall under thermal pressure. Experimental data shows that A… 50 B 40 Natural ventilation is the most effective, A 10 B 80 A 80 B 40 A 70 B 30 A 40 B 80 Secondly, the effective area ratio of natural ventilation is between 79.45% and 68.6%; overall, the AB cross arrangement has a better natural ventilation effect.

[0108] Natural ventilation mechanism: Natural ventilation in the AB opening combination is the result of a nonlinear coupling effect, where airflow around and recirculates on the roof, wind pressure is dominated by the Wenchuli effect under elevated structures, and vortex airflow driven by indoor thermal pressure is assisted. From the perspective of outdoor wind pressure driving effect, the cross combination of opening A at the near end of the windward side and opening B at the far end is as shown in A. 10 B 80 Air enters through port B, located in the recirculation zone, and exits through port A, located in the windward boundary separation zone. The high air pressure at both the inlet and outlet optimizes natural ventilation (e.g., ...). Figure 18 As shown). From the perspective of indoor thermal pressure driving effect, the airflow exhibits the characteristics of vortex flow between vertical air inlets and outlets, and multiple vortex combinations in the horizontal direction. The airflow is not simply from bottom to top or from bottom to top, but rather spreads horizontally while rolling in vortices, covering a larger area of ​​human activity. When the airflow vector direction at the AB opening is completely consistent with the vector direction of the vortex airflow, the natural ventilation effect reaches its optimum (e.g.). Figure 19 (As shown).

[0109] Overall, A 50 B 40 A 10 B 80 The combination and reasonable values ​​of the openings enable the effective use of the wind pressure intensity at the air inlet and outlet, and ensure that the vector directions of the wind pressure airflow and the vortex airflow are consistent. Wind pressure and thermal pressure are positively coupled, and the natural ventilation effect is optimized.

[0110] In steps S4 and S5 above, the optimization scheme and mechanism of natural ventilation based on the combination of three openings on the interface of the elevated waiting hall of the railway station are studied again. Based on the optimal scheme of the two-opening combination, the impact of adding a third opening on the natural ventilation of the waiting hall is further investigated, exploring the mechanism of natural ventilation based on the combination of three openings. Simulation results show that the effect of the third opening on the natural ventilation of the optimal two-opening scheme exhibits a non-linear superposition characteristic; it can both improve the ventilation efficiency of the two openings and potentially reduce their ventilation effect. Specific research details are as follows:

[0111] (1) Side unobstructed mode: under optimal operating condition C6B 90 Based on this, add ground opening A, with a value of 10-90m, to form C6B. 90 A. Opening combination; Experimental analysis revealed that C6B 90 A opening combination is better than C6B 90 The effect of natural ventilation did not change significantly, C6B 90 A 60 Relatively better. Under optimal operating condition C6B 90 Based on this, add a low-lying side window E on the leeward side, with a value of 1-9m, to form C6B. 90 E-opening combination; experimental analysis revealed that C6B 90 The natural ventilation effect of the E-opening combination is lower than that of the C6B. 90 To further reveal the natural ventilation patterns of the three-opening combination in this type of spatial pattern, the non-optimal operating condition C8B was selected. 90 Repeat the above experiment; experimental data shows that C8B 90 A opening combination significantly improves natural ventilation, C8B 90 The E-opening combination remains largely unchanged (e.g., ... Figures 20 to 21 (As shown).

[0112] Mechanism of natural ventilation: Opening A affects C6B 90 The airflow short-circuiting effect offsets the effect of promoting airflow diffusion, resulting in a weak effect on natural ventilation; opening A affects C8B. 90 Upward airflow has a significant downward promoting effect, pushing the airflow to spread in areas where people are active, thus improving the effect of natural ventilation (e.g. Figure 22 (As shown). Opening E weakens C6B. 90 The thermal pressure gradient of the airflow at the far end reduces the efficiency of natural ventilation; opening E versus C8B 90 The distribution of airflow in the area where people are active was not affected, and its effect on natural ventilation was minimal.

[0113] (2) Side upper semi-shading mode: Based on the optimal working condition C6E1, add ground opening A or roof opening B, with a value of 10-90m; experimental analysis found that the optimization effect of natural ventilation is not obvious, C6E1A90 Relatively superior. To further reveal the natural ventilation law of the three opening combinations in this spatial pattern, the above experiment was repeated under the non-optimal condition C1E1; the experimental data showed that the natural ventilation effect of C1E1A and C1E1B was significantly improved compared with C1E1 (e.g., Figures 23 to 24 (As shown).

[0114] Natural ventilation mechanism: Under optimal operating condition C6E1, the short-circuit effect of airflow at opening A offsets the effect of promoting airflow diffusion (e.g., Figure 25 As shown in the diagram, the thermal pressure exhaust at opening B only shares the negative pressure suction effect of opening E, and has a negligible effect on the overall natural ventilation effect. Under the non-optimal operating condition C1E1, opening A offsets the frictional resistance of the incident airflow, pushing the airflow to diffuse further away in the personnel activity area, thus improving the effectiveness of natural ventilation; the thermal pressure enhancement effect of opening B compensates for the unfavorable wind pressure, optimizing the natural ventilation effect.

[0115] (3) Side lower half-cover mode:

[0116] Under optimal working condition D 11 A 10 Based on this, add a high side window F on the leeward side to form D 11 A 10 F opening combination, adding roof opening B to form D 11 A 10 B opening combination; experimental analysis revealed that D 11 A 10 F, D 11 A 10 B is better than D. 11 A 10 Combination, D 11 A 10 B 60 Optimal. To further verify the natural ventilation law of the three opening combinations in this spatial mode, a non-optimal operating condition D was selected. 14 A 10 Repeat the above experiment; the data shows that: D 14 A 10 F, D 14 A 10 B. Natural ventilation effects were significantly improved (e.g.) Figures 26 to 27 (As shown).

[0117] Natural ventilation mechanism: Opening F is located in the negative pressure zone on the leeward side, forming a cross-flow driven by wind pressure with opening D on the windward side. Opening DF strengthens the wind pressure circulation, and opening DA maintains the thermal pressure gradient. The superposition of these two factors increases the airflow velocity, with optimal operation in condition D. 11 A 10 F 12 The effective area ratio reached 86.9%, compared to D 11 A10 An 8.8% improvement. While opening B introduces airflow short-circuiting, more importantly, it enhances the air intake velocity of opening D, thereby improving natural ventilation (e.g., Figure 28 (As shown). Opening F enhances wind pressure through leeward suction, while opening B increases wind speed through thermal buoyancy. Although their mechanisms differ, they both optimize the natural ventilation environment of the waiting hall.

[0118] In steps S4 and S5 of this specific embodiment, the optimization scheme and mechanism of the four opening combinations on the interface of the elevated waiting hall of the railway station are then studied: based on the preferred scheme of the three opening combinations, the impact of adding a fourth opening on the natural ventilation of the waiting hall is further studied, revealing the natural ventilation mechanism of the four opening combinations. Under the optimal operating condition C6B of the unobstructed mode... 90 A 60 Add a fourth opening E to form C6B. 90 A 60 E-opening combination; preferred operating condition C6E1A in upper semi-obstruction mode. 90 Add a fourth opening B to form C6E1A 90 B opening combination; preferred operating condition D in the lower semi-obstruction mode. 11 A 11 B 60 Add a fourth opening F to form D. 11 A 11 B 60 F-opening combination. The simulation results above show that, overall, the addition of the fourth opening has no significant effect on the natural ventilation of the waiting hall; in most operating conditions, the effective area ratio of natural ventilation decreases, except in C6B. 90 A 60 E6, C6E1A 90 B 80 C6E1A 90 B 90 D 11 A 10 B 60 F 10 The effective area ratio for natural ventilation is slightly increased with the combination of openings. The maximum optimization is C6E1A. 90 B 80 With the opening combination, the effective area ratio for natural ventilation increased from 89.19% to 93.01% (e.g., Figures 29-31 (As shown).

[0119] Natural ventilation mechanism: The introduction of the fourth type of opening further increases the complexity of the natural ventilation path in the waiting hall. When the natural ventilation path is nearly optimized with the three preferred opening options, the fourth opening typically causes pressure imbalance, weakens the thermo-pressure effect, and leads to backflow or vortex stagnation in some areas, causing the main airflow path to deviate or even short-circuit, thus reducing the effective ventilation area ratio. Therefore, the fourth opening should be used as a fine-tuning tool to compensate for ventilation blind spots, rather than as a primary means of improving overall efficiency. In practical applications, priority should be given to ensuring the smoothness of the dominant ventilation path and the stability of the system, and then using the fourth type of opening to optimize ventilation in blind spots.

[0120] In conclusion, the following conclusions can be drawn:

[0121] 1. Optimization of opening combination settings under different spatial modes: (1) Unobstructed side interface spatial mode. ① The low side window C on the windward side is used as the air inlet, and the roof opening B is used as the air outlet; the airflow path is that the air flows in through the opening C, sinks to the ground, flows to the leeward side, and rises to the roof opening B for discharge; ② While ensuring that the incoming airflow through the opening C is not obstructed by the ground, C should take an effective low position value to ensure that the horizontal jet is farther, and at the same time increase the vertical distance of CB; ③ Increase the horizontal distance of CB, that is, B is located at the far end of the windward side, which is conducive to the airflow path covering more personnel activity areas. ④ In the preferred scheme C6B 90 A third opening, A, C6B, is added to the ventilation path. 90 A 60 Slightly improve the natural ventilation effect; the addition of the third openings E and F has no effective effect. (2) Side surface upper shading space mode. ① The low side window C on the windward side is used as the air inlet, and the low side window E on the leeward side is used as the air outlet; the airflow path is that the air flows in through the C opening, sinks to the ground, and is discharged through the low side window E on the leeward side; ② The effective low position value is selected for the C opening and the low position value is selected for E, so that the CE airflow path is the shortest and flows through most of the personnel activity area; ③ On the preferred ventilation path C6E1, the third openings A and B are added, C6E1A 90 Slightly improve the natural ventilation effect. (3) Semi-obstructed space mode at the lower part of the side interface. ① The high side window D on the windward side is used as the air inlet, and the ground opening A is used as the air outlet. The airflow path is that the air flows in through the D opening, jets to the leeward side, sinks to the ground, and flows back to the ground opening A for discharge; ② While ensuring that the airflow entering through the D opening is not obstructed by the roof, D should be taken as an effective high value to ensure that the horizontal jet is farther, and at the same time, the vertical distance of DA should be appropriately increased; ③ A is taken at the near end of the windward side to ensure that the airflow returns to cover the area where people are active; ④ In the preferred scheme D 11 A 10Adding openings B and F along the ventilation path can increase horizontal wind pressure, promote horizontal jet flow, and facilitate natural ventilation. (4) Fully covered side surface space mode. ① Set ground opening A and roof opening B. The airflow path can be from A to B or from B to A. The airflow attributes are determined based on the relative positions of A and B. ② Cross-arrangement of A and B is the preferred choice. ③ By adjusting the relative positions of A and B, the natural ventilation effect of opening side windows can be basically achieved.

[0122] 2. Natural ventilation mechanism of interface opening combination: (1) Wind pressure-dominated jet deepening. Due to the influence of the external wind environment, the low side window C and high side window D in the positive pressure zone of the windward side are the preferred air inlets; C takes the effective low value and D takes the effective high value, eliminating the corner vortex obstruction and ensuring the horizontal jet pressure; the addition of openings A and E and openings B and F promotes the airflow from openings C and D to the far end to different degrees. The above three synergistic effects make wind pressure the dominant factor in the natural ventilation of the elevated waiting hall. The cross combination of openings A and B makes the positive and negative pressures match, increasing the wind pressure intensity. (2) Synergistic drive assisted by thermal pressure. By reasonably increasing the vertical distance between the air inlets and outlets, the thermal pressure gradient brought by the height of the waiting hall is fully utilized to promote the rise of the heated air near the ground and the sinking of the cooler air near the roof, forming a positive coupling effect with the wind pressure jet. The natural ventilation effect of the CB opening combination is better than that of CF and CA, due to the thermal pressure assistance brought by the roof opening B; the DA opening combination is better than that of DB and DF, due to the thermal pressure assistance brought by the increased vertical distance of DA. The AB opening combination can achieve a natural ventilation level similar to that of the C and D air inlets, which also utilizes this point. (3) Path-controlled airflow coverage. The CB combination takes the maximum value of B, which causes the horizontal jet to flow to the far end and cover the area where people are active; the DA combination takes the minimum value of D, which causes the airflow to flow back through the entire area where people are active; the AB cross arrangement causes the air entering the room to vortex and diffuse horizontally, and then rise or sink and flow out, increasing the impact on the area where people are active. The high and large space attributes of the elevated waiting hall determine that natural ventilation is not a simple linear superposition of the type and number of openings, but rather the optimization of wind pressure, thermal pressure and airflow path under the influence of the opening position and combination relationship. The optimization of two opening combinations and three and four opening combinations based on different spatial patterns provides direct methodological guidance for the design of the opening of the waiting hall space interface; the natural ventilation coordination mechanism based on wind pressure dominance, thermal pressure assistance and path control has guiding theoretical value.

[0123] There are many ways to implement the design method of the interface opening of the elevated waiting hall of a railway station based on natural ventilation. The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A design method for the interface opening of an elevated waiting hall in a railway station based on natural ventilation, wherein the elevated waiting hall is a cuboid structure, and its two short sides are respectively connected to corresponding entrance spaces; the entrance spaces are respectively located on both sides of the railway line; the elevated waiting hall is built above the railway station platform; various waiting areas and passenger passages between the waiting areas are arranged within the elevated waiting hall; other ancillary facilities besides the waiting areas and passenger passages are arranged inside the elevated waiting hall or on the two long sides of its exterior wall; the elevated waiting hall has an axial spatial characteristic; characterized in that... The longitudinal natural ventilation of the elevated waiting hall of the railway station is limited by the entrance space, and the lateral natural ventilation of the elevated waiting hall is related to the layout of other ancillary facilities. This design method includes: Step S1: Extract multiple spatial modes of the elevated waiting hall of the railway station; wherein, the multiple spatial modes include: side interface unobstructed mode, upper side interface semi-obstructed mode, lower side interface semi-obstructed mode, and side interface fully obstructed mode. The unobstructed side interface mode is as follows: the outer wall of the elevated waiting hall of the railway station is vertically divided into a first layer and a second layer from bottom to top; the other ancillary facilities are arranged inside the elevated waiting hall of the railway station; the other ancillary facilities divide the elevated waiting hall of the railway station into multiple parts; the side windows are opened on the first layer and / or the second layer; the elevated waiting hall of the railway station is naturally ventilated through the side windows opened on the outer wall; The upper semi-obstruction mode of the side interface is as follows: the outer wall of the elevated waiting hall of the railway station is divided into a first layer and a second layer vertically from bottom to top; the other ancillary facilities are arranged on the second layer; the side windows are opened on the first layer; the elevated waiting hall of the railway station is naturally ventilated through the side windows. The lower semi-obstructed mode of the side interface is as follows: the outer wall of the elevated waiting hall of the railway station is divided into a first layer and a second layer vertically from bottom to top; the other ancillary facilities are arranged on the first layer; the side windows are arranged on the second layer; the elevated waiting hall of the railway station is naturally ventilated through the side windows; The side interface full-coverage mode is as follows: the other ancillary facilities are arranged along the vertical direction of the outer wall of the elevated waiting hall of the railway station, and no side windows are opened on the outer wall of the elevated waiting hall of the railway station; The side windows on the first floor are low side windows; the side windows on the second floor are high side windows. Step S2: Based on the various spatial patterns, a numerical simulation method of computational fluid dynamics is selected to build a natural ventilation simulation experimental model of the elevated waiting hall of the railway station; wherein, the opening type of the natural ventilation simulation experimental model includes one or a combination of the following: ground opening A, roof opening B, low side window on the windward side C, high side window on the windward side D, low side window on the leeward side E, and high side window on the leeward side F. The number of openings corresponding to ground opening A, roof opening B, windward low side window C, windward high side window D, leeward low side window E, and leeward high side window F are all... indivual; The horizontal distance between the ground opening A and the windward side of the outer wall of the elevated waiting hall of the railway station is L1, and the horizontal distance between the roof opening B and the windward side of the outer wall of the elevated waiting hall of the railway station is L2. The windward low-side window C is at a height of H1 from the ground of the elevated waiting hall of the railway station; the windward high-side window D is at a height of H2 from the ground of the elevated waiting hall of the railway station; the leeward low-side window E is at a height of H3 from the ground of the elevated waiting hall of the railway station; and the leeward high-side window F is at a height of H4 from the ground of the elevated waiting hall of the railway station. And the ground opening A is expressed as A L1 The roof opening B is expressed as B. L2 The windward low-side window C is expressed in the form of C. H1 The windward high side window D is expressed in the form of D. H2 The leeward low-side window E is expressed as E H3 The leeward side window F is expressed as F H4 ; Step S3: Calculate the effective area ratio of natural ventilation in the natural ventilation simulation experiment model; Step S4: Sort the calculation results of the effective area ratio of natural ventilation in descending order; Step S5: Based on the ranking results of the effective area ratio of natural ventilation, the optimal opening design schemes for the elevated waiting hall of the railway station under the combinations of two, three, and four opening types are obtained, so as to achieve the best natural ventilation effect for the elevated waiting hall of the railway station under the combinations of two, three, and four opening types.

2. The design method for the interface opening of an elevated waiting hall in a railway station based on natural ventilation, as described in claim 1, is characterized in that... In step S2, the roof of the elevated waiting hall of the railway station corresponding to the natural ventilation simulation experimental model is a flat roof, and the dimensions of the elevated waiting hall of the railway station are length... Meters, width meters, height rice; The ground opening A, roof opening B, windward low side window C, windward high side window D, leeward low side window E, and leeward high side window F are all square in shape; the area of ​​each individual opening is... square meters; , , and All are positive numbers.

3. The design method for the interface opening of an elevated waiting hall in a railway station based on natural ventilation, as described in claim 2, is characterized in that... It is 200; It is 100; It is 20; =1; It is 14.

4. The design method for the interface opening of an elevated waiting hall in a railway station based on natural ventilation, as described in claim 1, is characterized in that... In step S2, the values ​​of L1 and L2 are both in the range of 10-90 m, and the interval between the values ​​of L1 and L2 is 10 m. The values ​​of H1 and H3 are both in the range of 1-9 m, and the values ​​of H2 and H4 are both in the range of 10-18 m. The interval between the values ​​of H1, H3, H2 and H4 is 1 m.

5. The design method for the interface opening of an elevated waiting hall in a railway station based on natural ventilation, as described in claim 1, is characterized in that... In step S3, the effective area ratio of natural ventilation is the ratio of the effective area of ​​natural ventilation in the area where the height of passengers in the elevated waiting hall of the railway station is 1.5m to the floor area of ​​the elevated waiting hall of the railway station. The effective area for natural ventilation is defined as the area in the elevated waiting hall of a railway station where the height of passengers is 1.5m and the wind speed is higher than 0.1m / s.

6. The design method for the interface opening of an elevated waiting hall in a railway station based on natural ventilation, as described in claim 5, is characterized in that... Step S3 specifically involves calculating the effective area ratio of natural ventilation in the natural ventilation simulation experiment model using a wind speed cloud map of the elevated waiting hall of a railway station at a height of 1.5m.

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