CN112283455A - Integrated directly-buried double-pipe fixed knot for directly-buried heat supply pipeline and calculation method thereof - Google Patents

Integrated directly-buried double-pipe fixed knot for directly-buried heat supply pipeline and calculation method thereof Download PDF

Info

Publication number
CN112283455A
CN112283455A CN202011143803.4A CN202011143803A CN112283455A CN 112283455 A CN112283455 A CN 112283455A CN 202011143803 A CN202011143803 A CN 202011143803A CN 112283455 A CN112283455 A CN 112283455A
Authority
CN
China
Prior art keywords
section
water supply
plate
pipe
thickness
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202011143803.4A
Other languages
Chinese (zh)
Inventor
柳颖
王雅明
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Tianjin Thermal Power Designing Institute Co ltd
Original Assignee
Tianjin Thermal Power Designing Institute Co ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Tianjin Thermal Power Designing Institute Co ltd filed Critical Tianjin Thermal Power Designing Institute Co ltd
Priority to CN202011143803.4A priority Critical patent/CN112283455A/en
Publication of CN112283455A publication Critical patent/CN112283455A/en
Pending legal-status Critical Current

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
    • F16L3/00—Supports for pipes, cables or protective tubing, e.g. hangers, holders, clamps, cleats, clips, brackets
    • F16L3/22—Supports for pipes, cables or protective tubing, e.g. hangers, holders, clamps, cleats, clips, brackets specially adapted for supporting a number of parallel pipes at intervals
    • F16L3/237—Supports for pipes, cables or protective tubing, e.g. hangers, holders, clamps, cleats, clips, brackets specially adapted for supporting a number of parallel pipes at intervals for two pipes
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
    • F16L3/00—Supports for pipes, cables or protective tubing, e.g. hangers, holders, clamps, cleats, clips, brackets
    • F16L3/08—Supports for pipes, cables or protective tubing, e.g. hangers, holders, clamps, cleats, clips, brackets substantially surrounding the pipe, cable or protective tubing
    • F16L3/12—Supports for pipes, cables or protective tubing, e.g. hangers, holders, clamps, cleats, clips, brackets substantially surrounding the pipe, cable or protective tubing comprising a member substantially surrounding the pipe, cable or protective tubing
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
    • F16L3/00—Supports for pipes, cables or protective tubing, e.g. hangers, holders, clamps, cleats, clips, brackets
    • F16L3/22—Supports for pipes, cables or protective tubing, e.g. hangers, holders, clamps, cleats, clips, brackets specially adapted for supporting a number of parallel pipes at intervals
    • F16L3/222—Supports for pipes, cables or protective tubing, e.g. hangers, holders, clamps, cleats, clips, brackets specially adapted for supporting a number of parallel pipes at intervals having single supports directly connected together
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F30/00—Computer-aided design [CAD]
    • G06F30/20—Design optimisation, verification or simulation
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F2113/00—Details relating to the application field
    • G06F2113/14—Pipes
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F2119/00—Details relating to the type or aim of the analysis or the optimisation
    • G06F2119/14—Force analysis or force optimisation, e.g. static or dynamic forces

Abstract

The invention relates to an integral type direct-buried double-pipe fixed knot for a direct-buried heat supply pipeline and a calculation method thereof, wherein the double-pipe fixed knot is characterized by comprising a double-pipe fixed knot main body consisting of an H-shaped member and a water supply pipe section and a water return pipe section, wherein the H-shaped member consists of a web plate and two wing plates; the H-shaped member web plate is provided with a water supply pipe section hole and a water return pipe section hole, and the water supply pipe section and the water return pipe section respectively pass through the water supply pipe section hole and the water return pipe section hole and are symmetrically arranged on the front side and the rear side of the web plate; the front side and the rear side of the web plate are symmetrically provided with a plurality of ribbed plates which are uniformly and symmetrically arranged around the water supply and return pipe sections along the radial direction and are connected between the water supply and return pipe sections, and the water supply and return pipe sections, the wing plates and the side edge of the web plate are connected between the water supply and return pipe sections; the outer side of the fixing section main body is coated with an insulating layer and a protective layer. The calculation method comprises the steps of calculating thrust moment, calculating wing plate size, determining web plate size and determining the number of rib plates. The steel and concrete structure fixing pier is replaced by the one-step formed metal structure fixing section, and the steel and concrete structure fixing pier is small in size, light in weight, buried underground directly and simple and convenient to construct.

Description

Integrated directly-buried double-pipe fixed knot for directly-buried heat supply pipeline and calculation method thereof
Technical Field
The invention relates to the technical field of fixed piers for a direct-buried heat supply pipeline, in particular to an integrated direct-buried double-pipe fixed knot for the direct-buried heat supply pipeline and a calculation method thereof.
Background
In laying the direct-buried heat supply pipeline, in order to keep the structure firm, the location is firm, indeformable, need set up the anchor block at a certain distance. The fixed pier generally adopts a reinforced concrete structure, and as shown in fig. 1, a reinforced concrete fixed pier A0 is formed by pouring two parallel water supply and return water fixing joints B1 and B2 which are respectively connected with a water supply and return water heat supply pipeline into a reinforced concrete pier body A1. The water supply and return fixing joints B1 and B2 are water supply and return pipe sections D1 and D2 with outer middle parts provided with annular plates C and two ends extending out of the front and rear side surfaces of the fixing pier, respectively, and the water supply and return pipe sections D1 and D2 are used as pipeline connecting pieces and two ends of the water supply and return pipe sections are respectively connected with a laid water supply pipe and a laid water return pipe in a welding mode.
In practical application, the fixed piers bear great acting force of the heat supply pipeline, and the acting force is transmitted to the concrete pier bodies through the fixed joints and then transmitted to the surrounding soil bodies by the concrete pier bodies to bear the acting force.
The main defect of the reinforced concrete pier body is that the acting force of the heat supply pipeline is completely transmitted to the fixed pier through the fixed knot and then counteracted by the surrounding soil body, so the size of the fixed pier is often very large. In engineering construction, the fixed pier which meets the requirements often cannot be manufactured according to the normal size under the limitation of site conditions. In addition, during construction, the fixed joints are prefabricated pipe fittings which can be provided at any time according to needs, but concrete pouring is site construction, and abnormal conditions exist due to unpredictability of underground site conditions, so that the reinforced concrete fixed pier with the conventional structure cannot be normally constructed; in particular, due to the limitation of construction period and the like, the concrete often cannot reach the maintenance period, the performance and quality of the fixed piers are directly influenced, and the firmness and stability of the heat supply pipeline are finally influenced.
In view of the above, the prior patent CN204986035U "a pier integrating a water supply fixing section and a water return fixing section" of the applicant provides a pier integrating a water supply fixing section and a water return fixing section fixedly connected together by an H-shaped steel connector, wherein both the water supply pipe section and the water return pipe section vertically penetrate through a web plate of the H-shaped steel and are fixedly connected to the web plate by annular plates outside the water supply pipe section and the water return pipe section respectively. The action parts of the two pipelines on the concrete are converted into the action between the pipelines, the unbalanced action of the two pipelines is converted into more balanced combined action and then transmitted to the fixed piers, the acting force of the fixed piers on the pipelines is greatly weakened, and the concrete body is not required to bear the acting force. However, because the H-shaped steel is welded on site, the H-shaped steel needs to be protected and then directly buried underground, a concrete protective layer needs to be wrapped on each side of the fixing section with the H-shaped steel and exceeds the surface of the H-shaped steel by a certain thickness, and the protective layer has the function of protecting and also solves the instability problem of the H-shaped steel in application.
It can be seen from the above that, in the existing fixing pier with the water supply and return fixing sections connected into a whole, the water supply and return fixing sections are constructed by using prefabricated belt-shaped plate split fixing sections as ready-made structural members, but the H-shaped steel is temporarily connected on site and connected to the annular plates outside the water supply and return pipe sections. Therefore, the structural member is a field processing assembly, wherein the water supply and return fixing sections are prefabricated parts with manufactured protective layers, H-shaped steel needs to be welded in a secondary processing mode, field protection needs to be carried out, and in addition, in H-shaped steel material selection calculation, commercially available general specification H-shaped steel with similar numerical values is selected according to acting force of a heat supply pipeline, the specification of the existing commercially available H-shaped steel cannot completely meet the requirement, particularly the problem of instability of the H-shaped steel in application exists, and the problems need to be solved by combining concrete.
Application practices show that the on-site secondary combined structure has the defects that construction is complex, labor and time are wasted, the size and specification of the H-shaped steel sold in the market cannot meet application requirements, particularly, a protective layer of the H-shaped steel is required to be applied subsequently and instability is required to be overcome, concrete needs to be combined, the improved steel and concrete mixed structure is still formed, and the problems of volume occupation, maintenance period, environment adaptation, construction quality and efficiency and the like caused by concrete construction exist although the amount and the volume of the concrete are greatly reduced.
How to improve on current reinforced concrete anchor block structure basis, get rid of the concrete, avoid adding secondary operation's structure and eliminate the unstability drawback to research and develop a novel one-piece type stationary node, replace the anchor block that steel and concrete mix with the single metallic structure stationary node of one shot forming, thereby realize that small volume is light, the construction is simple and direct, the effect that saves labour saving and time saving and guarantee the quality becomes industry concern problem.
Disclosure of Invention
The invention mainly aims to solve the problems and provides an integrated directly-buried double-pipe fixed knot for a directly-buried heat supply pipeline and a calculation method thereof.
The technical scheme adopted by the invention for solving the technical problems is as follows:
an integrated directly-buried double-pipe fixed joint for a directly-buried heat supply pipeline is characterized by comprising a double-pipe fixed joint main body consisting of an H-shaped component, a water supply pipe section and a water return pipe section, wherein the H-shaped component consists of a web plate and two wing plates which are symmetrically and vertically connected with each other at the top edge and the bottom edge of the web plate, and the size values of the web plate and the two wing plates are numerical values calculated according to the use requirements; the web plate of the H-shaped component is symmetrically provided with water supply and return pipe section holes along the center of the horizontal center line of the H-shaped component, the water supply and return pipe sections respectively penetrate through the water supply and return pipe section holes in a way of being vertical to the web plate and are symmetrically arranged on the front side and the rear side of the web plate, and the water supply and return pipe sections are respectively fixed on the web plate in a way that the pipe walls of the water supply and return pipe sections holes are respectively clung to the hole walls of; the front side and the rear side of the web plate are symmetrically provided with a plurality of rib plates, the rib plates are respectively and uniformly distributed and symmetrically arranged around the water supply pipe section and the water return pipe section along the radial direction of the water supply pipe section and the water return pipe section and are connected between the water supply pipe section and the water return pipe section and the wing plate and the web plate side edge which are respectively on; and the outer side of the fixing joint main body is sequentially coated with an insulating layer and a protective layer from inside to outside.
The thickness of the rib plate is the same as that of the wing plate, and the height of the rib plate is the same as the extending width of the wing plate; the number of the rib plates is set according to the rule that: when the diameter of the pipeline is less than or equal to DN150, two sides of the web plate are respectively provided with 4 ribbed plates with the thickness of 8 mm; when the diameter of the pipeline is within the range of DN 200-600, two sides of the web plate are respectively provided with 8 ribbed plates with the thickness of 8 mm; when the diameter of the pipeline is within the range of DN 700-1000, two sides of the web plate are respectively provided with 12 ribbed plates with the thickness of 20 mm; when the diameter of the pipeline is in the range of DN 1200-1400, two sides of the web plate are respectively provided with 16 rib plates with the thickness of 25 mm.
The double-pipe fixing joint main body is an integral steel casting.
The heat-insulating layer is a polyurethane foam layer with the thickness of 50-60 mm; the protective layer is a high-density polyethylene layer with the thickness of 6-8 mm.
A calculation method of the double-pipe fixed joint main body of the directly-buried double-pipe fixed joint is characterized by comprising the following steps:
(1) calculating the moment of the water return pipe generated by the thrust borne by the water supply pipe at the web plate position of the double-pipe fixed joint main body;
(1.1) determining a reasonable center distance of the water supply and return pipes according to different pipe diameters;
(1.2) calculating the moment;
M＝T*d；
wherein M is moment, (KNm);
t is the double-pipe fixed joint thrust of the water supply pipe, (KN);
d is the center distance (m) of the water supply pipe and the water return pipe;
(2) calculating wing panel dimensions;
(2.1) determining the net section modulus of the wing plate capable of bearing the moment M strength according to the following sections and items (i) to (iv) of the Steel Structure design Standard GB 50017-2017:
6.1.1 section of calculation formula;
TABLE 3.5.1 "class and limit of width-to-thickness ratio of plate";
item 6.1.2 provisions on the coefficient of section plasticity development;
TABLE 4.4.1 "Strength index for Steel design";
section 6.1.1 of the calculation formula:
Figure BDA0002739054630000041
in the formula:
Mx、Mydesign values for bending moments (N mm) around the x-axis and the y-axis at the same section;
Wnx、Wnymodulus of the clear section (mm) for the x-axis and the y-axis3)；
γx、γy-section plastic development coefficients for the principal axes x, y;
f-design value of bending Strength of Steel Material (N/mm)2)；
The water supply pipe and the water return pipe connected with the double-pipe fixed joint main body are laid along the X-axis direction, and the vertical pipeline laying direction is the y-axis;
here, for the double tube fixed joint main body: my＝M；Mx＝0；
In the table 3.5.1 of the grades and the limits of the width-thickness ratio of the plate, the width-thickness ratio of the plate is divided into 5 grades S1-S5;
item 6.1.2 specifies "gammax、γyThe following values are specified: when the plate width-to-thickness ratio is at S4 or S5, the coefficient of section plasticity development should be taken to be 1. "
Here, for the double tube fixed joint main body: gamma rayyTaking 1;
fourthly, according to the application convention, the thickness value of the plate applied to the double-pipe fixed joint main body is within the range of 16-40 mm; accordingly, according to the table 4.4.1, the material and bending strength design value f of the plate is determined;
thus, the combined cross section W of the two wing plates can be calculated from My, γ y and fnyModulus of neat section:
Wny≥My/(γy*f)；
(2.2) deriving a wing plate calculation formula;
(2.2.1) determination of the net section modulus W of the combination of 2 rectangles of area by tny: according to the material mechanics formula, the moment of inertia I of the rectangular sectiony1＝t*by312, obtaining 2 rectangular combined section inertia moments I with the area by ty＝2*t*by3/12；
(2.2.2) is defined according to the formula provided in section 6.1.1 of "design Standard for Steel Structure" GB 50017-2017: wnx、WnyIs the net section modulus for the x-axis and y-axis. The section modulus is the section resisting moment, which is known from material mechanics and is the ratio of the moment of inertia of the section to the centroid axis of the section to the distance from the farthest point on the section to the centroid axis. Thus, the combined modulus W of the 2 rectangles with the area by t rectangley＝Iy/by/2＝2tby 26; then derive: wy＝2tby 26; since the section is weakened without holes or the like, the net section modulus is equal to the section modulus, Wny＝Wy；
In the formula: wnyIs the rectangular net section modulus;
Wyis a rectangular section modulus;
t is the wing thickness (mm);
by is the flap width (mm);
(2.3) trial calculation and determination of flap size:
(2.3.1) firstly, setting a value of the thickness t of the wing plate, and calculating the value of the width by of the wing plate;
(2.3.2) setting the web thickness tfTaking the thickness t of the webfThe set value of (1) is the set value of the thickness t of the wing plate;
(2.3.3) calculating the value of the wing plate overhanging width b;
(2.3.4) calculating the value of flap length L0;
wing length L0 ═ d +2R +2d1
Wherein: d is the center distance of the water supply pipe and the water return pipe;
r is the radius of the water supply pipe and the water return pipe;
d1 is the length of the rib plate connecting section extending from the wing plate at the outer side of the water supply and return pipe;
(2.3.5) calculating the ratio S of the wing plate overhanging width b to the thickness t of the wing plate, namely b/t, if the S value is in the range of S4-S5, meeting the requirement, and obtaining a wing plate thickness determination value and a wing plate overhanging width determination value; otherwise, trial calculation is carried out again;
adding allowance on the basis of the determined wing plate thickness value to serve as an application value of the wing plate thickness;
(3) determining a web dimension: the web thickness value is the same as the determined wing plate thickness value, the web height value is larger than the outer diameter of the water supply and return pipe by 100-120 mm, and the web length value is the same as the wing plate length value;
(4) and arranging ribbed plates on the web plate to determine the reasonable number of the ribbed plates.
The invention has the beneficial effects that: compared with the prior art, the integrated directly-buried double-pipe fixing joint has the advantages that the double-pipe fixing joint body is composed of an H-shaped component, a water supply pipe section and a water return pipe section, the H-shaped component is composed of a web plate and two wing plates, the size values of the web plate and the two wing plates are numerical values calculated according to using requirements, and the integrated directly-buried double-pipe fixing joint is not a finished product of the existing commercially-available section steel, so that the integrated directly-buried double-pipe fixing joint is accurate in size and. Furthermore, ribbed plates are additionally arranged on the web plate and connected between the water supply pipe section and the water return pipe section, between the water supply pipe section and the water return pipe section and the web plate side edge on the same side. Therefore, concrete is not needed, and the instability problem is further solved. The main body of the double-pipe fixed joint is an integral steel casting, the heat preservation layer and the protective layer are externally coated on the whole body at one time, and the prefabricated part is directly used as a finished pipe fitting in the field pipeline direct-buried laying construction, so that the field welding and concrete coating operation are omitted, and the concrete structure is also removed. The performance index of the original concrete fixing pier can be achieved by adopting the small and light double-pipe fixing joint, the problem of environmental limitation is solved, the application range is enlarged, the construction process is simplified by directly burying underground, labor, time and labor are saved, the construction quality is ensured, and the construction efficiency is improved.
The invention further provides a calculation method based on the steel structure design standard GB50017-2017, the sizes of two wing plates and web plates of the double-pipe fixed joint main body are calculated scientifically, and the rib plates are selected appropriately, so that the performance quality of the integrated directly-buried double-pipe fixed joint for removing concrete provided by the invention is ensured, and the firmness and the stability of a heat supply pipeline are realized. Application practices show that the double-pipe fixing knot is adopted to ensure that the heat supply pipe network runs stably and safely and reaches the normal use standard. The pipe fitting has wide application prospect.
Drawings
FIG. 1 is a schematic structural view of a concrete anchor block for a conventional direct-buried heat supply pipeline;
FIG. 2 is a view showing the external form of the integral type buried double pipe fixing joint according to the present invention;
FIG. 3 is a schematic perspective view of the double-tube fixing joint body in FIG. 2
FIG. 4 is a front view of the double tube fixing joint body of FIG. 2
FIG. 5 is a schematic structural dimension view of a cross section of an H-shaped member;
FIG. 6 is a force analysis diagram of an integrated directly-buried double-pipe fixed joint;
fig. 7 is a schematic view of the pipeline layout for the present invention in use in a heating pipeline.
In the figure:
the device comprises an A0 reinforced concrete fixed pier, an A1 pier body, a B1 water supply fixed joint, a B2 water return fixed joint, a C annular plate, a D1 water supply pipe section, a D2 water return pipe section, an E integrated directly-buried double-pipe fixed joint, an F double-pipe fixed joint main body, a G water supply pipeline and an H water return pipeline;
the width of a by wing plate, the extension width of a b wing plate, the center distance of a d supply water return pipeline and a d return water pipeline, the length of a rib plate connecting section extending from the wing plate on the outer side of the d1 supply water return pipeline and the rib plate connecting section, the height of an h web plate and the height of an h1 rib plate; t wing panel thickness, tf web thickness; l0 wing plate length, L1-L2 double-tube fixed internode distance, L3 web plate length;
the water supply system comprises 11 water supply pipe sections, 12 water return pipe sections, 2H-shaped components, 21 wing plates, 22 webs, 3 ribbed plates, 4 heat preservation layers, 5 protective layers and 6 compensators.
The invention is described in detail below with reference to the figures and examples.
Detailed Description
Fig. 2 to 6 show an integrated directly-buried double-pipe fixed knot E for a directly-buried heat supply pipeline, which is characterized by comprising a double-pipe fixed knot body F consisting of an H-shaped member 2 and water supply and return pipe sections 11 and 12, wherein the H-shaped member consists of a web plate 22 and two wing plates 21 which are symmetrically and vertically connected with each other at the top edge and the bottom edge of the web plate, and the size values of the web plate and the two wing plates are values calculated according to the use requirements; the web plate 22 of the H-shaped member is symmetrically provided with water supply and return pipe section holes along the center of the horizontal center line, the water supply and return pipe sections 11 and 12 respectively penetrate through the water supply and return pipe section holes in a vertical manner and are symmetrically arranged on two sides of the web plate, and the wall of each of the water supply and return pipe sections 11 and 12 is respectively clung to the hole wall of the water supply and return pipe section hole and is fixed on the web plate 22.
The front and rear side plate surfaces of the web plate 22 are symmetrically provided with a plurality of rib plates 3 which are respectively and uniformly distributed and symmetrically arranged around the water supply and return pipe sections 11 and 12 along the radial direction and are connected between the water supply and return pipe sections, and the water supply and return pipe sections are respectively and symmetrically arranged between the wing plate 21 and the web plate 22 side edge on the same side; and the outer side of the fixing section main body F is sequentially coated with an insulating layer 4 and a protective layer 5 from inside to outside.
A further feature of the invention is that the thickness of the rib 3 is the same as the thickness t of the wing, and the height h1 of the rib 3 is the same as the wing overhang width b. The number of the rib plates is set according to the rule that: when the diameter of the pipeline is less than or equal to DN150, two sides of the web plate are respectively provided with 4 ribbed plates with the thickness of 8 mm; when the diameter of the pipeline is within the range of DN 200-600, two sides of the web plate are respectively provided with 8 ribbed plates with the thickness of 8 mm; when the diameter of the pipeline is within the range of DN 700-1000, two sides of the web plate are respectively provided with 12 ribbed plates with the thickness of 20 mm; when the diameter of the pipeline is in the range of DN 1200-1400, two sides of the web plate are respectively provided with 16 rib plates with the thickness of 25 mm.
The invention is also characterized in that the double-pipe fixing joint main body E is an integral steel casting which is integrally cast and formed during processing.
The invention is also characterized in that the heat-insulating layer 4 is a polyurethane foam layer with the thickness of 50-60 mm; the protective layer 4 is a high-density polyethylene layer with the thickness of 6-8 mm.
Working principle of the invention
The integral type directly buried double pipe fixing joint is hereinafter referred to as a "double pipe fixing joint".
The heat supply pipeline generally has two pipelines, one is a water supply pipe and the other is a water return pipe. The water medium is sent to the heat consumer from the heat source through the water supply pipe, and after the heat is dissipated by the heat consumer, the water temperature is reduced, and the water medium returns to the heat source through the water return pipe. The water supply pipe is high in water temperature, thrust is generated at the position of the double-pipe fixed joint E during operation due to expansion with heat and contraction with cold, the thrust is transmitted to the web plate due to the fact that the web plate 22 is directly connected with the pipeline, and the water return pipe is in a normal temperature state without hot water at the moment. Then the moment with the water return pipe as the action point and the central distance d between the water supply pipe and the water return pipe as the force arm is formed at the web plate. And the thrust of expansion with heat and contraction with cold is born by the double-pipe fixed joint. The thrust is transmitted to the web plate, the web plate is not enough to bear the moment, and the wing plates 21 are arranged on the top edge and the bottom edge of the web plate to bear the moment, so that the balance of the thermal action force is realized. The sizes of the wing plates and the web plates are determined by calculation and state analysis, and the requirements for bearing the thrust of the pipeline are met scientifically and accurately. Especially, rib plates are uniformly and symmetrically arranged around the water supply and return pipe sections along the radial direction of the water supply and return pipe sections, and the rib plates are welded with the pipe wall, the web plate and the wing plate in a surrounding way on three sides, so that the pipeline is reinforced at a double-pipe fixed joint; but also solves the instability of the plate.
In the early stage, two fixing joint parts with annular outer edges are poured in reinforced concrete, and the thrust of the two fixing joints is borne by the concrete. In recent years, the fixed pier added with the H-shaped steel connecting piece saves concrete bearing thrust. However, because the instability problem is overcome, concrete still needs to be combined to solve the protection problem to form a steel and concrete mixed structure, and the problems of volume occupation, environmental limitation, maintenance period and the like caused by concrete construction still exist.
The invention provides an integrated directly-buried double-pipe fixed knot through structural improvement, and the size and the number of each structural part of a fixed knot main body F are determined by scientific calculation aiming at different heat supply pipelines. Especially, the double-pipe fixed joint is cast into an integral piece, the insulating layer and the protective layer are externally coated integrally at one time, secondary processing is not needed, the double-pipe fixed joint is directly buried underground during construction, the use is convenient, the engineering construction period is shortened, the engineering investment is saved, and the construction quality is ensured.
The invention provides a calculation method of the double-pipe fixed joint main body F of the double-pipe fixed joint E. The calculation steps are described in detail below with reference to specific examples.
As shown in fig. 7, the heat supply pipeline is a section of nodes (i) to (v) directly buried in Tianjin, the nodes (i), (iii) and (v) are double-pipe fixed nodes (E), the nodes (i), and (iv) are compensators (6), the buried depth is 1.5m, the pipe diameter is DN600, and the center distance d of the pipeline is 1 m. The distance between the fixed joints of the double pipes is L1-L2-70 m. The temperature of the water supply and return is 130/70 ℃, and the pressure is 1.6 MPa. In the figure, G denotes a water supply pipe, and H denotes a water return pipe. In the heat supply pipeline, the thrust T born by the fixed knot is 400 KN.
At this time, the construction unit puts forward the order conditions of the node and the fixed node to the manufacturer, namely: the technical indexes of the double-pipe fixed joint are as follows: "DN 600, PN16, T400 KN", DN600 denotes a pipe with a nominal diameter of 600 mm; PN16 represents a design pressure of 1.6mpa, which controls the pipe wall thickness; t400 KN indicates the fixed joint thrust 400 KN.
The thrust is calculated by adopting a conventional algorithm according to CJJ/T81-2013 technical Specification for urban heating direct-buried hot water pipelines.
For the engineering, the double-pipe fixed joint provided by the invention is adopted as the fixed joint, and the thrust T is the thrust borne by the water supply pipe at the position of the web plate of the main body F of the double-pipe fixed joint.
Aiming at the heat supply pipeline, the method for calculating the double-pipe fixed knot main body of the double-pipe fixed knot comprises the following specific steps:
(1) calculating the moment of the water return pipe generated by the thrust borne by the water supply pipe at the web plate position of the double-pipe fixed joint main body;
(1.1) determining a reasonable center distance d of the water supply and return pipes according to different pipe diameters;
the center distance d of a water supply and return pipe provided by a checking construction unit is 1m, the outer diameter of a given directly-buried DN600 pipeline containing a heat insulation layer and a protective layer is 760mm, and a double-pipe fixed joint adopts water supply and return pipe sections 11 and 12 which are 2m long. During construction, two ends of the water supply and return pipe sections are required to be welded with the water supply and return pipe, so that a welding operation space is considered for the value d, the pipeline clear distance is about 200mm, and the moment is increased if the value d is too large. Therefore, d 1m given by this construction unit is suitable.
(1.2) calculating the moment;
M＝T*d；
wherein M is torque; (KNm);
t is the double-pipe fixed joint thrust of the water supply pipe, (KN);
d is the center distance (m) of the water supply pipe and the water return pipe;
referring to fig. 5-6, the pipeline is laid along the X-axis direction. O1 is the axis of the water supply pipe; o2 is the axis of the return pipe; t is the thrust of the double-pipe fixed joint of the water supply pipeline, namely the thrust borne by the water supply pipe at the position of the web plate. The torque M generated when T equals 400KNB＝400KNM。
(2) Calculating wing panel dimensions;
(2.1) determining the net section modulus of the wing plate capable of bearing the moment M strength according to the following sections and items of GB 50017-2017:
6.1.1 section of calculation formula,
TABLE 3.5.1 "class and limit of width-to-thickness ratio of plate";
item 6.1.2 provisions on the coefficient of section plasticity development;
TABLE 4.4.1 "Strength index for Steel design";
section 6.1.1 of the calculation formula:
Figure BDA0002739054630000101
in the formula:
Mx、Mydesign values for bending moments around the x-axis and the y-axis at the same section (N mm);
Wnx、Wnymodulus of the clear section for the x-axis and the y-axis, (mm)3)；
γx、γy-section plastic development coefficients for the principal axes x, y;
f-design value of bending strength of Steel, (N/mm)2)；
The water supply pipe and the water return pipe connected with the double-pipe fixed joint main body are laid along the X-axis direction, and the vertical pipeline laying direction is the y-axis;
here, for the double tube fixed joint main body: my＝M；Mx＝0；
In the 'class and limit of the width-thickness ratio of the plate' in table 3.5.1, the width-thickness ratio of the plate is classified into 5 classes S1-S5, the higher the class is, the larger the width-thickness ratio of the plate is, the wider the plate is;
item 6.1.2 specifies "gammax、γyThe following values are specified: when the plate width-to-thickness ratio is at S4 or S5, the coefficient of section plasticity development should be taken to be 1. ";
here, for the double tube fixed joint main body: gamma rayyTaking 1;
fourthly, according to the application convention, the thickness value of the plate applied to the double-pipe fixed joint main body is within the range of 16-40 mm;
application practices show that the fixed knot of the direct-buried heat supply pipeline generally bears larger thrust, and steel with the thickness less than 16mm is not suitable for the fixed knot; the steel with the thickness of more than 40mm has changed characteristics, and belongs to unconventional application, so the thickness range of the plate used by the fixed joint is 16-40 mm.
Accordingly, the design values f of the material quality and bending strength of the steel material are determined according to Table 4.4.1,
in this example: selecting a material Q235B for the plate with the thickness ranging from 16mm to 40mm,
f＝205N/mm2；
thus, can be composed of My、γyAnd f calculating the combined section W of the two wing platesnyA net section modulus of;
Wny≥My/(γy*f)＝400*106/(1*205)＝1951cm3。
(2.2) deriving a calculation formula for the wing plate
(2.2.1) determination of the net section modulus W of the combination of 2 rectangles of area by tny：
Referring to FIG. 5, the rectangular section moment of inertia I is calculated according to the material mechanics equationy1＝t*by312, obtaining 2 rectangular combined section inertia moments I with the area by ty＝2*t*by3/12；
(2.2.2) is defined according to the formula provided in section 6.1.1 of "design Standard for Steel Structure" GB 50017-2017: wnx、WnyIs the net section modulus for the x-axis and y-axis. The section modulus is the section resisting moment, which is known from material mechanics and is the ratio of the moment of inertia of the section to the centroid axis of the section to the distance from the farthest point on the section to the centroid axis. Thus, the combined modulus W of the 2 rectangles with the area by t rectangley＝Iy/by/2＝2tby 26; then derive: wy＝2tby 26; since the section is weakened without openings or the like, the net section modulus is equal to the section modulus,
i.e. Wny＝Wy；
In the formula: wnyIs the rectangular net section modulus;
Wyis a rectangular section modulus;
t is the wing thickness (mm);
by is the flap width (mm);
(2.3) trial calculating and determining the size of the wing plate;
(2.3.1) firstly, setting a value of the thickness t of the wing plate, and calculating the value of the width by of the wing plate;
from Wny＝2tby2/6＝1951cm3，
Q235B steel plate with the thickness t of wing plate being 20mm is selected,
then by is 54cm, namely the width of the wing plate is more than or equal to 54cm, and by is 600 mm;
(2.3.2) setting the web thickness tfTaking the thickness t of the webfThe set value of (1) is the set value of the thickness t of the wing plate;
the "plate width to thickness ratio" in table 3.5.1 above corresponds to the ratio of the wing overhang width b to its thickness t, and therefore also the web thickness needs to be determined. For DN600 and PN16 direct burial heat supply pipelines, the wall thickness of the pipeline is generally 8mm, and according to the equal strength principle, the thickness of the web can be 8 mm. However, the difference between the thickness of the wing plate and the thickness of the wing plate is larger by 20mm, and the thinner the plate is, the more easily the instability is, and particularly, the structure of the invention has no concrete constraint, so that the size and the instability of the plate need to be considered together. Here, the web is made of a steel plate having a thickness of 20 mm. I.e. web thickness tf＝20mm
(2.3.3) calculating the value of the wing plate overhanging width b;
referring to fig. 5, b ═ by-tf)/2＝(600-20)/2＝290mm；
(2.3.4) calculating the value of flap length L0;
wing length L0 ═ d +2R +2d1
Wherein: d is the center distance of the water supply pipe and the water return pipe;
r is the radius of the water supply pipe and the water return pipe;
d1 is the length of the rib plate connecting section extending from the wing plate at the outer side of the water supply and return pipe;
as can be seen from fig. 6, the wing plates are not stressed except at the two sides of the pipeline, and only the structural requirements need to be met. Namely, the outside of the water supply pipe and the water return pipe is provided with a ribbed plate connecting section which extends for 100 mm. The flap length L0 ═ 1000+2 × 630/2+2 × 100 ═ 1830 mm.
(2.3.5) calculating the ratio S of the wing plate overhanging width b to the thickness t of the wing plate, namely b/t, if the S value is in the range of S4-S5, meeting the requirement, and obtaining a wing plate thickness determination value and a wing plate overhanging width determination value; otherwise, trial calculation is carried out again;
in this example, the flap projecting width b is 290mm, and S/t is 290/20 is 14.5. Corresponding to the S4 rating requirement in table 3.5.1 above. Thus, a wing thickness determination value of 20mm and a wing overhang width determination value of 290mm were obtained.
In practical application, in order to improve the structural safety, the margin of 2mm is added on the basis of the determined thickness value of the wing plate of 20mm, and the determined thickness value is used as the application value of the thickness of the wing plate. The flap thickness application value of this example was 22 mm.
(3) Determining a web dimension: the web thickness value is the same as the determined wing plate thickness value, the web height value is larger than the outer diameter of the water supply and return pipe by 100-120 mm, and the web length value is the same as the wing plate length value;
for DN600, PN16 direct burial heat supply pipeline, the specification of the pipeline is phi 630 x 8, in this example, according to the equal strength principle, the thickness t of the web platefThe value is 20mm same as the determined value of the thickness of the wing plate, the height value of the web plate is 120mm larger than the outer diameter of the water supply pipe and the water return pipe which is 630mm, and the height h of the web plate is 750mm, and the length L3 of the web plate is 1830 mm.
(4) Arranging rib plates on the web plate, and determining the reasonable number of the rib plates;
in the calculation, the thickness of the web plate is 20mm, the thickness of the web plate is close to the thickness application value of the wing plate, but the difference between the thickness of the web plate and the thickness of the wall of the pipeline is larger and is not equal to 8mm, and therefore rib plates are uniformly and symmetrically arranged around the water supply pipe section and the water return pipe section along the radial direction of the water supply pipe section and the water return pipe section. The ribbed plates are welded with the pipe wall, the web plate and the wing plate in a surrounding way on three sides, so that the pipeline is reinforced at the double-pipe fixed joint; but also solves the instability of the plate. In this example, corresponding to DN600 direct burial heat supply pipeline, the diameter of the pipeline is in the range of DN 200-600, and two sides of the web are respectively provided with 8 ribbed slabs with the thickness of 8 mm.
Thus, the calculation is completed.
In this embodiment, the following is calculated by the above method: web thickness tf20mm, 750mm web height h and wing plate thicknessThe degree t is 20mm, the application value of the thickness of the wing plate is 22mm, the width by of the wing plate is 600mm, the extending width b of the wing plate is 290mm, and the length L3 of the web plate is 1830 mm. And two sides of the web plate are respectively provided with 8 ribs with the thickness of 8mm, and the height h1 of the ribs is 290mm which is the extending width b of the wing plate.
In the embodiment, the thickness of the polyurethane foam plastic heat-insulating layer coated on the outer side of the double-pipe fixing joint main body is 54 mm; the thickness of the high-density polyethylene protective layer is 8 mm.
Application practices prove that the integrated directly-buried double-pipe fixing joint provided by the invention has the advantages that compared with the existing concrete-combined fixing pier, the volume is remarkably reduced, the problem of environmental limitation is solved, the application range is expanded, and the construction quality is ensured; the underground is directly buried, the construction flow is simplified, labor and time are saved, the construction efficiency is improved, the stable and safe operation of a heat supply pipe network is ensured, and the normal use standard is reached. The pipe fitting has wide application prospect.
The foregoing is merely a preferred embodiment of the invention and is not intended to limit the scope of the invention in any way. Any simple modification, equivalent change and modification made to the above embodiments according to the technical spirit of the present invention still fall within the scope of the technical solution of the present invention.

Claims (5)

1. An integrated directly-buried double-pipe fixed joint for a directly-buried heat supply pipeline is characterized by comprising a double-pipe fixed joint main body consisting of an H-shaped component, a water supply pipe section and a water return pipe section, wherein the H-shaped component consists of a web plate and two wing plates which are symmetrically and vertically connected with each other at the top edge and the bottom edge of the web plate, and the size values of the web plate and the two wing plates are numerical values calculated according to the use requirements; the web plate of the H-shaped component is symmetrically provided with water supply and return pipe section holes along the center of the horizontal center line of the H-shaped component, the water supply and return pipe sections respectively penetrate through the water supply and return pipe section holes in a way of being vertical to the web plate and are symmetrically arranged on the front side and the rear side of the web plate, and the water supply and return pipe sections are respectively fixed on the web plate in a way that the pipe walls of the water supply and return pipe sections holes are respectively clung to the hole walls of; the front side and the rear side of the web plate are symmetrically provided with a plurality of rib plates, the rib plates are respectively and uniformly distributed and symmetrically arranged around the water supply pipe section and the water return pipe section along the radial direction of the water supply pipe section and the water return pipe section and are connected between the water supply pipe section and the water return pipe section and the wing plate and the web plate side edge which are respectively on; and the outer side of the fixing joint main body is sequentially coated with an insulating layer and a protective layer from inside to outside.
2. The integral type direct burial double pipe fixing knot for the direct burial heat supply pipeline according to claim 1, wherein the rib plate has a thickness equal to that of the wing plate, and the height of the rib plate is equal to the extending width of the wing plate; the number of the rib plates is set according to the rule that: when the diameter of the pipeline is less than or equal to DN150, two sides of the web plate are respectively provided with 4 ribbed plates with the thickness of 8 mm; when the diameter of the pipeline is within the range of DN 200-600, two sides of the web plate are respectively provided with 8 ribbed plates with the thickness of 8 mm; when the diameter of the pipeline is within the range of DN 700-1000, two sides of the web plate are respectively provided with 12 ribbed plates with the thickness of 20 mm; when the diameter of the pipeline is in the range of DN 1200-1400, two sides of the web plate are respectively provided with 16 rib plates with the thickness of 25 mm.
3. An integral type direct burial double pipe fixing knot for a direct burial heat supply pipeline according to claim 1 or 2, wherein the double pipe fixing knot body is an integral steel casting.
4. The integrated type direct-burial double-pipe fixing knot for the direct-burial heat supply pipeline according to claim 3, wherein the heat insulation layer is a polyurethane foam layer with the thickness of 50-60 mm; the protective layer is a high-density polyethylene layer with the thickness of 6-8 mm.
5. A method for calculating a double pipe fixing joint body of a buried double pipe fixing joint according to claim 4, comprising the steps of:
(1) calculating the moment of the water return pipe generated by the thrust borne by the water supply pipe at the web plate position of the double-pipe fixed joint main body;
(1.1) determining a reasonable center distance of the water supply and return pipes according to different pipe diameters;
(1.2) calculating the moment;
M＝T*d；
wherein M is moment, (KNm);
t is the double-pipe fixed joint thrust of the water supply pipe, (KN);
d is the center distance (m) of the water supply pipe and the water return pipe;
(2) calculating wing panel dimensions;
(2.1) determining the net section modulus of the wing plate capable of bearing the moment M strength according to the following sections and items (i) to (iv) of the Steel Structure design Standard GB 50017-2017:
6.1.1 section of calculation formula;
TABLE 3.5.1 "class and limit of width-to-thickness ratio of plate";
item 6.1.2 provisions on the coefficient of section plasticity development;
TABLE 4.4.1 "Strength index for Steel design";
section 6.1.1 of the calculation formula:
Figure FDA0002739054620000021
in the formula:
Mx、Mydesign values for bending moments (N mm) around the x-axis and the y-axis at the same section;
Wnx、Wnymodulus of the clear section (mm) for the x-axis and the y-axis3)；
γx、γy-section plastic development coefficients for the principal axes x, y;
f-design value of bending Strength of Steel Material (N/mm)2)；
The water supply pipe and the water return pipe connected with the double-pipe fixed joint main body are laid along the X-axis direction, and the vertical pipeline laying direction is the y-axis;
here, for the double tube fixed joint main body: my＝M；Mx＝0；
In the table 3.5.1 of the grades and the limits of the width-thickness ratio of the plate, the width-thickness ratio of the plate is divided into 5 grades S1-S5;
item 6.1.2 specifies "gammax、γyThe following values are specified: when the plate width-to-thickness ratio is at S4 or S5, the coefficient of section plasticity development should be taken to be 1. "
Here, for the double tube fixed joint main body: gamma rayyTaking 1;
fourthly, according to the application convention, the thickness value of the plate applied to the double-pipe fixed joint main body is within the range of 16-40 mm; accordingly, according to the table 4.4.1, the material and bending strength design value f of the plate is determined;
thus, the combined cross section W of the two wing plates can be calculated from My, γ y and fnyModulus of neat section:
Wny≥My/(γy*f)；
(2.2) deriving a wing plate calculation formula;
(2.2.1) determination of the net section modulus W of the combination of 2 rectangles of area by tny: according to the material mechanics formula, the moment of inertia I of the rectangular sectiony1＝t*by312, obtaining 2 rectangular combined section inertia moments I with the area by ty＝2*t*by3/12；
(2.2.2) is defined according to the formula provided in section 6.1.1 of "design Standard for Steel Structure" GB 50017-2017: wnx、WnyIs the net section modulus for the x-axis and y-axis. The section modulus is the section resisting moment, which is known from material mechanics and is the ratio of the moment of inertia of the section to the centroid axis of the section to the distance from the farthest point on the section to the centroid axis. Thus, the combined modulus W of the 2 rectangles with the area by t rectangley＝Iy/by/2＝2tby26; then derive: wy＝2tby26; since the section is weakened without holes or the like, the net section modulus is equal to the section modulus, Wny＝Wy；
In the formula: wnyIs the rectangular net section modulus;
Wyis a rectangular section modulus;
t is the wing thickness (mm);
by is the flap width (mm);
(2.3) trial calculation and determination of flap size:
(2.3.1) firstly, setting a value of the thickness t of the wing plate, and calculating the value of the width by of the wing plate;
(2.3.2) setting the web thickness tfTaking the thickness t of the webfThe set value of (1) is the set value of the thickness t of the wing plate;
(2.3.3) calculating the value of the wing plate overhanging width b;
(2.3.4) calculating the value of flap length L0;
wing length L0 ═ d +2R +2d1
Wherein: d is the center distance of the water supply pipe and the water return pipe;
r is the radius of the water supply pipe and the water return pipe;
d1 is the length of the rib plate connecting section extending from the wing plate at the outer side of the water supply and return pipe;
(2.3.5) calculating the ratio S of the wing plate overhanging width b to the thickness t of the wing plate, namely b/t, if the S value is in the range of S4-S5, meeting the requirement, and obtaining a wing plate thickness determination value and a wing plate overhanging width determination value; otherwise, trial calculation is carried out again;
adding allowance on the basis of the determined wing plate thickness value to serve as an application value of the wing plate thickness;
(3) determining a web dimension: the web thickness value is the same as the determined wing plate thickness value, the web height value is larger than the outer diameter of the water supply and return pipe by 100-120 mm, and the web length value is the same as the wing plate length value;
(4) and arranging ribbed plates on the web plate to determine the reasonable number of the ribbed plates.
CN202011143803.4A 2020-10-23 2020-10-23 Integrated directly-buried double-pipe fixed knot for directly-buried heat supply pipeline and calculation method thereof Pending CN112283455A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202011143803.4A CN112283455A (en) 2020-10-23 2020-10-23 Integrated directly-buried double-pipe fixed knot for directly-buried heat supply pipeline and calculation method thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202011143803.4A CN112283455A (en) 2020-10-23 2020-10-23 Integrated directly-buried double-pipe fixed knot for directly-buried heat supply pipeline and calculation method thereof

Publications (1)

Publication Number Publication Date
CN112283455A true CN112283455A (en) 2021-01-29

Family

ID=74424785

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202011143803.4A Pending CN112283455A (en) 2020-10-23 2020-10-23 Integrated directly-buried double-pipe fixed knot for directly-buried heat supply pipeline and calculation method thereof

Country Status (1)

Country Link
CN (1) CN112283455A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114414176A (en) * 2022-03-30 2022-04-29 风凯换热器制造(常州)有限公司 Processing method and leakage detection method for double-layer conveying pipeline

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114414176A (en) * 2022-03-30 2022-04-29 风凯换热器制造(常州)有限公司 Processing method and leakage detection method for double-layer conveying pipeline
CN114414176B (en) * 2022-03-30 2022-06-03 风凯换热器制造(常州)有限公司 Processing method and leakage detection method for double-layer conveying pipeline

Similar Documents

Publication Publication Date Title
Pandey et al. Design of cold-formed high strength steel tubular T-joints under compression loads
CN112283455A (en) Integrated directly-buried double-pipe fixed knot for directly-buried heat supply pipeline and calculation method thereof
CN206360086U (en) Clod wash multi-cavity steel tube concrete Special-Shaped Column and the rigid connection node of U-shaped combination beam
KR20080108880A (en) Trench forme method for the steel concrete column
CN108104271A (en) Clod wash multi-cavity steel tube concrete Special-Shaped Column and the rigid connection node of U-shaped combination beam
CN213839853U (en) Integral direct-buried double-pipe fixing joint for direct-buried heat supply pipeline
CN207740609U (en) A kind of direct burial threeway reinforcing heat distribution pipeline
CN104652704A (en) Connected installation and calculation methods for inner pipes and outer pipes of pipe-in-pipe concrete-filled steel tube tension members
CN107725966A (en) A kind of liner RPC thin-walled reparation pipes and its restorative procedure for broken pipe reparation
CN107420652B (en) Diplopore thermal pipe arranged side by side
Gresnigt et al. Strength and deformation capacity of bends in pipelines
CN107940105B (en) Steel structure fixed pier with channel steel connected with water supply and return fixed joint and channel steel calculation method
Pandey et al. Numerical analysis and design of cold-formed high strength steel RHS X-joints at elevated temperatures
CN112682605A (en) Direct-buried corrugated pipe compensator with adjustable connecting pipe installation gradient
CN108941949B (en) Welding method for reducing field welding stress deformation of thick-wall steel structure
CN109990142B (en) Research method for anti-leakage and anti-blocking scheme of pipeline sleeve in fabricated building structure
CN102268873B (en) Heavy steel support and processing method thereof
Pandey et al. S960 steel grade square bird-beak T-and X-joints: Numerical investigation and design
CN204922353U (en) External fixation festival in steel bushing steel steam direct -burried pipeline
CN208650912U (en) Heat distribution pipeline fixing force transfer bracket system in heating power shield tunnel
CN207921570U (en) It is a kind of to facilitate splicing and the PE pipe fittings with heat sinking function
CN210141378U (en) Direct-buried heat supply pipeline with different limiting and compensating structures for water supply and return pipelines
Berti et al. Technical forum: buckling of steel tunnel liner under external pressure
Reid et al. The modeling of a thermosyphon type permafrost protection device
CN108915768A (en) Heat distribution pipeline fixing force transfer bracket system in heating power shield tunnel

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination