Simulation method of internal pressure balance type sleeve compensator in CAESAR II

Abstract

The application provides a simulation method of an internal pressure balance type sleeve compensator in CAESAR II, and the simulation method comprises the following steps: S1: general model establishment: nodes matched with the sleeve compensator are established and numbered, and a general model is obtained through modeling according to the established nodes; S2: general model import: the general model in S1 is imported into a pipe network model, and the position of the general model is adjusted to make the corresponding end points of the pipe network model and the general model coincide. The application expands the application scene of the CAESAR II software, fills the missing sleeve compensator simulation function of the software, and is helpful for designers to improve the efficiency and accuracy of the calculation results when facing the stress calculation task of a complex "pipe network taking the sleeve compensator as the main compensation means".

Description

TECHNICAL FIELD

[0001] The present application relates to the field of simulation calculation of compensators in CAESAR II, and particularly to a simulation method of an internal pressure balanced sleeve compensator in CAESAR II. BACKGROUND

[0002] Regarding the sleeve compensator, it is often arranged on a heat pipe to absorb the thermal elongation of the pipe along the axial direction; according to whether it can self-digest the internal pressure blind plate force, it is divided into balanced type and unbalanced type; when calculating the thrust of the fixed point of the pipe arranged with the unbalanced sleeve compensator, in addition to considering the secondary stress caused by the thermal expansion of the pipe, the primary stress caused by the medium pressure in the pipe also needs to be considered; when calculating the thrust of the fixed point of the pipe arranged with the balanced sleeve compensator, only the secondary stress caused by the thermal expansion of the pipe needs to be considered, and therefore the balanced sleeve compensator is also called the non-thrust sleeve compensator.

[0003] Regarding CAESAR II, as a commercial software, it is used for stress simulation calculation of various pipe networks, and the simulation steps are as follows:

[0004] a. Pipe network model establishment: establishing a pipe network model according to a routing scheme and pipe specifications;

[0005] b. Material parameter setting: defining the parameters and physical properties of the pipe material, insulation material and medium in the pipe;

[0006] c. Boundary condition input: setting a fixed point, a sliding point, a guide and a compensator, inputting a friction coefficient, a degree of freedom stiffness and other parameters;

[0007] d. Running condition setting: setting pipe network running condition according to actual conditions;

[0008] e. Calculation result checking: after the software simulation calculation is completed, the user adjusts the pipe network setting scheme according to the results.

[0009] For the compensator simulation in step c, the software provides two methods: natural compensation and artificial compensation; when the natural compensation is selected, the user can set the natural compensator according to the actual conditions of the pipe network, and then according to the simulation calculation results of the software, the rationality of the compensation scheme is determined; when the artificial compensation is selected, the software provides a complete function board for simulating the corrugated compensator, and the user can set the types of rigid parts, the types of end parts, the specifications of the compensator and related parameters for simulation calculation according to actual needs; but the built-in artificial compensation of the software only has one form of corrugation, and lacks a function board for simulating the sleeve compensator.

[0010] The in-plant heating pipe network of a thermal power plant and some municipal heating branch pipe networks in some areas are mostly in the form of overhead laying, and for long-distance straight pipe sections requiring axial compensation, artificial compensation schemes are mostly used, and natural compensation is only used at individual positions.

[0011] In addition, the above-mentioned pipe specifications are generally below DN500, and if a large number of corrugated compensators are used, the pipe network cost will be affected, so the owner usually prefers to use sleeve compensators as an artificial compensation scheme.

[0012] In the product brochure of a regular manufacturer, parameters such as material, outer dimensions and friction force values of various sleeve compensators are provided for designers to select and use when calculating pipe stress; for pipe sections with short distances and simple structures, designers can directly use the values provided in the brochure to calculate the fixed point load, although there are errors, but they are within an acceptable range; but for complex pipe networks, there can be large differences in the specifications (such as pipe diameter, material, insulation size, etc.) and boundary conditions (such as the friction coefficient of the sliding support, the degree of freedom of the pipe, the form of the compensator, etc.) on both sides of the fixed point. The mutual influence of these differences makes it difficult for designers to obtain accurate loads at the fixed point within a limited time through manual calculation or experience-based estimation, and only simulation calculation with software can be used.

[0013] Since there is no function board and usage guide for sleeve compensators in CAESAR II, users can only complete the simulation calculation of sleeve compensators through self-modeling, but the wrong modeling method will directly lead to wrong simulation results, and currently there is almost no literature on "simulation of sleeve compensators in CAESAR II", so it is necessary to explore a correct simulation method for sleeve compensators in CAESAR II. SUMMARY

[0014] The present application provides a simulation method for an internal pressure balanced sleeve compensator in CAESAR II, which enables the software to achieve a breakthrough from 0 to 1 in the stress simulation calculation scenario of "pipe network using sleeve compensators as the main compensation means".

[0015] The technical means adopted by the present application are as follows:

[0016] A simulation method for an internal pressure balanced sleeve compensator in CAESAR II, the simulation method comprising the following steps:

[0017] S1: General model establishment: establish nodes matching the sleeve compensator and number them, and model according to the established nodes to obtain a general model;

[0018] S2: general model import: import the general model in S1 into the pipe network model, and adjust the position of the general model to make the pipe network model coincide with the corresponding endpoints of the general model.

[0019] As preferred, in S1, when establishing the nodes matching the sleeve compensator, each node is numbered at least 6 digits N1-N6, wherein:

[0020] N1-N3 represent the specifications of the sleeve compensator;

[0021] N4 represents the fixed end or the movable end of the sleeve compensator;

[0022] N5-N6 represent the position of the node in the general model.

[0023] As preferred, when the node represents the fixed end of the sleeve compensator, N4=0, when the node represents the movable end of the sleeve compensator, N4=9; and the N5-N6 of the node representing the fixed end or the movable end of the sleeve compensator are numbered in turn from 10 with an interval of 10, obtaining:

[0024] The nodes representing the fixed end are 5, in turn: N1N2N3010, N1N2N3020, N1N2N3030, N1N2N3040 and N1N2N3050;

[0025] The nodes representing the movable end are 3, in turn: N1N2N3910, N1N2N3920 and N1N2N3930.

[0026] As preferred, when establishing the general model:

[0027] The nodes N1N2N3010-N1N2N3020 are selected as the straight pipe section of the sleeve compensator transition pipe;

[0028] The nodes N1N2N3020-N1N2N3030 are selected as the variable diameter section of the sleeve compensator reducer;

[0029] The nodes N1N2N3030-N1N2N3040 are selected as the straight pipe section of the sleeve compensator outer sleeve pipe before the work pipe;

[0030] The nodes N1N2N3040-N1N2N3050 are selected as the straight pipe section of the sleeve compensator outer sleeve pipe surrounding the work pipe;

[0031] The nodes N1N2N3910-N1N2N3920 are selected as the straight pipe section of the sleeve compensator work pipe inside the outer sleeve pipe;

[0032] The nodes N1N2N3920-N1N2N3930 are selected as the straight pipe section of the sleeve compensator work pipe outside the outer sleeve pipe;

[0033] And further set the specifications of the pipeline, so that:

[0034] The transition pipe specification = the working pipe specification = the pipe section specification where the sleeve compensator is located;

[0035] The outer sleeve inner diameter = the working pipe outer diameter;

[0036] The straight pipe section L2 of the outer sleeve before the working pipe ≥ 1.5 times the thermal elongation of the straight pipe section at that location.

[0037] As a preferred, further interrelating the nodes N1N2N3040 and N1N2N3910, respectively establishing:

[0038] a. Vertical direction constraint, constraint type Y, mutually constrain vertical direction displacement;

[0039] b. Horizontal lateral constraint, constraint type Z, mutually constrain horizontal lateral displacement;

[0040] c. Axis direction constraint, constraint type X2, bilinear constraint axis direction displacement;

[0041] When the thrust caused by the thermal expansion of the pipe sections where the two nodes are located < the yield force Fy, the stiffness of this constraint is +∞, and the displacement = 0;

[0042] When the thrust caused by the thermal expansion of the pipe sections where the two nodes are located ≥ the yield force Fy, the stiffness of this constraint is 0, and the displacement ≥ 0;

[0043] Wherein, the yield force Fy = the sleeve compensator friction force;

[0044] And further interrelating the nodes N1N2N3050 and N1N2N3920, respectively establishing:

[0045] d. Vertical direction constraint, constraint type Y, mutually constrain vertical direction displacement;

[0046] e. Horizontal lateral constraint, constraint type Z, mutually constrain horizontal lateral displacement.

[0047] As a preferred, before importing the general model in S1 into the pipe network model, add a 1-bit number N0 before the original 6-bit number of each node, indicating the number of each sleeve compensator, with the number N0 starting from 1 and numbered sequentially with an interval of 1.

[0048] As a preferred, after importing the general model into the pipe network model, the node N1N2N3010 is located at the origin of the Cartesian coordinate system of the pipe network model space, and the coordinates of this node are manually adjusted to adjust the position of the general model, so that the corresponding end points of the pipe network model and the general model coincide, and,

[0049] When the fixed end of the general model is connected with the pipe network model endpoint, the end node number of the pipe network is changed to N1N2N3010, the downstream pipe network node of the active end of the general model is numbered from N1N2N3930, and the modeling is performed in the mode of "inserting a new unit after the current unit";

[0050] When the active end of the general model is connected with the pipe network endpoint, the end node number of the pipe network is changed to N1N2N3930, the downstream pipe network node of the fixed end of the general model is numbered from N1N2N3010, and the modeling is performed in the mode of "inserting a new unit before the current unit".

[0051] Compared with the prior art, the present application has the following advantages:

[0052] 1. The present application expands the application scenarios of the CAESAR II software and fills the missing sleeve compensator simulation function of the software.

[0053] 2. It is helpful for designers to improve the efficiency and accuracy of the calculation results when facing the complex stress calculation task of "pipe network with sleeve compensator as the main compensation means". BRIEF DESCRIPTION OF DRAWINGS

[0054] Figure 1 It is a simulation schematic diagram of the sleeve compensator general model of the present application.

[0055] Figure 2 It is Figure 1 A specific embodiment of the general model.

[0056] Figure 3 It is Figure 2 The finished general model diagram of the embodiment. DETAILED DESCRIPTION

[0057] As shown in 1-3, the following specific embodiments are provided.

[0058] A simulation method of an internal pressure balance type sleeve compensator in CAESAR II, the simulation method comprising the following steps:

[0059] S1: General model establishment: establishing and numbering nodes matched with the sleeve compensator, and modeling according to the established nodes to obtain a general model;

[0060] S2: General model import: importing the general model in S1 into a pipe network model, and adjusting the position of the general model to make the corresponding endpoints of the pipe network model and the general model coincide.

[0061] In S1, first, node numbering is performed, and when establishing nodes matched with the sleeve compensator, each node is numbered at least 6 digits N1-N6, wherein:

[0062] N1-N3 represent the specifications of the sleeve compensator; for example, when the specification is DN300, N1=3, N2=0, N3=0, and when the specification is DN65, N1=0, N2=6, N3=5.

[0063] N4 represents the fixed end or the movable end of the sleeve compensator; when the node represents the fixed end of the sleeve compensator, N4 = 0, and when the node represents the movable end of the sleeve compensator, N4 = 9.

[0064] N5-N6 represent the location of the node in the general model; the nodes N5-N6 representing the fixed or movable end of the sleeve compensator are numbered sequentially starting from 10, with an interval of 10.

[0065] like Figure 1 As shown, we obtain:

[0066] There are 5 nodes indicating the fixed end, namely: N1N2N3010, N1N2N3020, N1N2N3030, N1N2N3040 and N1N2N3050;

[0067] The active node consists of 3 nodes, namely: N1N2N3910, N1N2N3920 and N1N2N3930.

[0068] Next, we begin modeling. When establishing a general model, such as... Figure 1 As shown:

[0069] Select nodes N1N2N3010-N1N2N3020 as the straight pipe section of the sleeve compensator transition pipe;

[0070] Select nodes N1N2N3020-N1N2N3030 as the reducing section of the sleeve compensator;

[0071] Select nodes N1N2N3030-N1N2N3040 as the straight pipe section of the sleeve compensator outer sleeve located before the working pipe;

[0072] Select nodes N1N2N3040-N1N2N3050 as the straight pipe sections surrounding the working pipe of the sleeve compensator outer sleeve;

[0073] Select nodes N1N2N3910-N1N2N3920 as the straight pipe section located inside the outer sleeve of the sleeve compensator working pipe;

[0074] Select nodes N1N2N3920-N1N2N3930 as the straight pipe section located outside the outer sleeve of the working pipe of the sleeve compensator;

[0075] And further specify the pipe specifications so that:

[0076] Transition pipe specification = working pipe specification = sleeve compensator located pipe segment specification;

[0077] Outer sleeve inner diameter = working pipe outer diameter; outer sleeve outer diameter refers to the manufacturer's sample book;

[0078] The straight pipe segment L2 of the outer sleeve before the working pipe is ≥1.5 times the thermal elongation of the straight pipe segment at that point; or refer to the manufacturer's sample book; and the distance L1 between the two end nodes of the sleeve compensator refers to the manufacturer's sample book.

[0079] Further, the nodes N1N2N3040 and N1N2N3910 are associated with each other, respectively establishing:

[0080] a. Vertical direction constraint, constraint type Y, mutual constraint of vertical direction displacement;

[0081] b. Horizontal lateral constraint, constraint type Z, mutual constraint of horizontal lateral displacement;

[0082] c. Axial direction constraint, constraint type X2, bilinear constraint of axial direction displacement;

[0083] When the thrust caused by the thermal expansion of the pipe segment where the two nodes are located is < the yield force Fy, the stiffness of the constraint is +∞, and the displacement = 0; expressed as K1 = 1E+12 (software does not recognize +∞, usually 1E+12 is used to represent infinity) ;

[0084] When the thrust caused by the thermal expansion of the pipe segment where the two nodes are located is ≥ the yield force Fy, the stiffness of the constraint is 0, and the displacement is ≥ 0; expressed as K2 = 1 (software does not recognize 0, usually 1 is used to represent infinite tend to 0).

[0085] Wherein, the yield force Fy = sleeve compensator friction force, the value of which refers to the manufacturer's sample book, which is different from the default.

[0086] And further make the nodes N1N2N3050 and N1N2N3920 associated with each other, respectively establishing:

[0087] d. Vertical direction constraint, constraint type Y, mutual constraint of vertical direction displacement;

[0088] e. Horizontal lateral constraint, constraint type Z, mutual constraint of horizontal lateral displacement.

[0089] In addition, the sleeve compensator body material refers to the manufacturer's sample book, and the pipe medium type, operating temperature and pressure, pipe insulation material and thickness, etc. Parameters are input according to the actual engineering situation.

[0090] Next, the model is imported.

[0091] Before importing the general model in S1 into the pipe network model, to avoid the node number duplication in the pipe network model when multiple sleeve compensators of the same specification appear, 1-bit number N0 is added before the original 6-bit number of each node, which is used to represent the number of each sleeve compensator, and the number N0 is numbered from 1 in sequence with an interval of 1.

[0092] When the model is imported, the import operation is as follows:

[0093] 1. Select "Environment" in the tool bar and "Include Piping Files" in the drop-down menu in sequence;

[0094] 2. Select the local saved general model file in the dialog box, and change "Read" to "Y" to ensure that the model can still be edited after being imported;

[0095] 3. "Confirm".

[0096] After the general model is imported into the pipe network model, the general model and the pipe network model are still two independent models, and they need to be manually merged. The specific operation method is as follows:

[0097] 1. After the general model is imported, its nodes N1, N2, N3, 10 are located at the origin of the Cartesian coordinate system of the pipe network model space, and the node coordinates need to be manually adjusted to adjust the position of the general model, so that the corresponding end points of the pipe network model and the general model coincide.

[0098] 2. When the fixed end of the general model is connected with the end point of the pipe network model, the end node number of the pipe network is changed to N1, N2, N3, 10, and the downstream pipe network node of the active end of the general model is numbered from N1, N2, N3, 30, and the modeling is performed in the mode of "inserting a new unit after the current unit".

[0099] 3. When the active end of the general model is connected with the end point of the pipe network, the end node number of the pipe network is changed to N1, N2, N3, 30, and the downstream pipe network node of the fixed end of the general model is numbered from N1, N2, N3, 10, and the modeling is performed in the mode of "inserting a new unit before the current unit".

[0100] 4. The guide support of the active end pipe is set according to the spacing recommended by the manufacturer's manual.

[0101] and as shown in Figure 2 , there is provided the following specific embodiment.

[0102] Figure 2The shown is the inner pressure balanced sleeve compensator with DN300 specification, the data provided by the manufacturer's brochure: the compensator material is Q235B, the total length is 2.5 m, and the friction force is 188.68 kN. It is applied to the heating pipe network in a thermal power plant with a temperature of 110 / 70 DEG C, the pipe network operating pressure is 0.9 MPa, the pipe material is 20# steel, the specification is D325*8, the thermal insulation material is centrifugal glass wool, and the thermal insulation layer thickness is 80 mm;

[0103] As Figure 2 shown, in the establishment stage of the general model, the 6 node numbers N1-N6 are respectively: 300010, 300020, 300030, 300040, 300050, 300910, 300920 and 300930.

[0104] (1) Node 300010-300020: straight pipe section (transition pipe), length 400 mm;

[0105] (2) Node 300020-300030: reducing section (reducing pipe), length 100 mm;

[0106] (3) Node 300030-300040: straight pipe section (outer sleeve pipe), length 800 mm;

[0107] (4) Node 300040-300050: straight pipe section (outer sleeve pipe), length 800 mm;

[0108] (5) Node 300910-300920: straight pipe section (working pipe), length 800 mm;

[0109] (6) Node 300920-300930: straight pipe section (working pipe), length 400 mm;

[0110] (7) Transition pipe specification = working pipe specification = sleeve compensator pipe section specification = D325*8;

[0111] (8) Outer sleeve pipe inner diameter = working pipe outer diameter = 325 mm;

[0112] (9) Outer sleeve pipe outer diameter = 525 mm;

[0113] (10) L2 = 800 mm;

[0114] (11) L1 = 2500 mm;

[0115] (12) Node 300040 and 300910 are associated with each other, respectively establishing:

[0116] a. Vertical direction constraint, constraint type Y, mutual constraint vertical direction displacement;

[0117] b. Horizontal lateral constraint, constraint type is Z, mutually constrain horizontal lateral displacement;

[0118] c. Axis direction constraint, constraint type is X2, bilinear constraint axis direction displacement;

[0119] When the thrust caused by the thermal expansion of the pipe section is less than the yield force Fy, the stiffness of the constraint is +∞, the displacement is 0, and K1 is 1E+12;

[0120] When the thrust caused by the thermal expansion of the pipe section is greater than or equal to the yield force Fy, the stiffness of the constraint is 0, the displacement is greater than or equal to 0, and K2 is 1;

[0121] The yield force Fy is the friction of the sleeve compensator, which is 188.68kN, and the rest is default;

[0122] (13) The nodes 300050 and 300920 are associated with each other, and the following are established respectively:

[0123] a. Vertical direction constraint, constraint type is Y, mutually constrain vertical direction displacement;

[0124] b. Horizontal lateral constraint, constraint type is Z, mutually constrain horizontal lateral displacement;

[0125] (14) The sleeve compensator body material is Q235B.

[0126] The general model of the finished product is shown in Figure 3 .

[0127] It should be noted that the protection scope of the present application also includes 21 kinds of general models of internal pressure balanced sleeve compensators with specifications from DN50 to DN1400, and the simulation calculation results of these models in the pipe network model have been verified.

Claims

1. A simulation method for an internal pressure balanced sleeve compensator in CAESAR II, characterized in that, The simulation method includes the following steps: S1: General Model Establishment: Establish and number the nodes that match the sleeve compensator, and perform modeling based on the established nodes to obtain the general model; S2: Import the general model: Import the general model from S1 into the pipeline network model, and adjust the position of the general model so that the corresponding endpoints of the pipeline network model and the general model coincide. In S1, when establishing nodes that match the sleeve compensator, each node is numbered with at least 6 digits N1-N6, where: N1-N3 represent the specifications of the sleeve compensator; N4 indicates the fixed end or movable end of the sleeve compensator; N5-N6 represent the positions of the nodes in the general model; When a node represents the fixed end of the sleeve compensator, N4=0; when a node represents the movable end of the sleeve compensator, N4=9; and for nodes representing either the fixed or movable end of the sleeve compensator, N5-N6 are numbered sequentially starting from 10, with an interval of 10, resulting in: There are 5 nodes indicating the fixed end, namely: N1N2N3010, N1N2N3020, N1N2N3030, N1N2N3040 and N1N2N3050; The active node consists of 3 nodes, namely: N1N2N3910, N1N2N3920 and N1N2N3930; When establishing a general model: Select nodes N1N2N3010-N1N2N3020 as the straight pipe sections of the sleeve compensator transition pipe; Select nodes N1N2N3020-N1N2N3030 as the reducing section of the sleeve compensator; Select nodes N1N2N3030-N1N2N3040 as the straight pipe section of the sleeve compensator outer sleeve located before the working pipe; Select nodes N1N2N3040-N1N2N3050 as the straight pipe sections surrounding the working pipe of the sleeve compensator outer sleeve; Select nodes N1N2N3910-N1N2N3920 as the straight pipe sections located inside the outer sleeve of the sleeve compensator working pipe; Select nodes N1N2N3920-N1N2N3930 as the straight pipe section located outside the outer sleeve of the working pipe of the sleeve compensator; And further specify the pipe specifications so that: Transition pipe specifications = Working pipe specifications = Pipe section specifications where the sleeve compensator is located; Outer tube inner diameter = working tube outer diameter; The straight pipe section L2 of the outer jacket located before the working pipe is greater than or equal to 1.5 times the thermal elongation of that straight pipe section.

2. The simulation method of an internal pressure balanced sleeve compensator in CAESAR II according to claim 1, characterized in that, To further associate nodes N1N2N3040 and N1N2N3910, establish the following connections: a. Vertical constraint, constraint type Y, mutually constraining vertical displacement; b. Horizontal lateral constraints, constraint type Z, mutually constraining horizontal lateral displacements; c. Axial direction constraint, constraint type X2, bilinear constraint axial direction displacement; When the thrust caused by the thermal expansion of the pipe section where the two nodes are located is less than the yield force Fy, the stiffness of the constraint is +∞ and the displacement is 0. When the thrust caused by the thermal expansion of the pipe section where the two nodes are located is greater than or equal to the yield force Fy, the stiffness of the constraint is 0 and the displacement is greater than or equal to 0. Wherein, yield force Fy = frictional force of sleeve compensator; Furthermore, to further associate nodes N1N2N3050 and N1N2N3920, establish the following connections: d. Vertical constraint, constraint type Y, mutually constraining vertical displacement; e. Horizontal lateral constraints, constraint type Z, mutually constraining horizontal lateral displacements.

3. The simulation method of an internal pressure balanced sleeve compensator in CAESAR II according to claim 2, characterized in that, Before importing the general model in S1 into the pipeline network model, add a number N0 before the original 6-digit number of each node to represent the number of each sleeve compensator. The number N0 starts from 1 and is numbered sequentially with an interval of 1.

4. The simulation method of an internal pressure balanced sleeve compensator in CAESAR II according to claim 3, characterized in that, After importing the pipeline network model into the general model, node N1N2N3010 is located at the origin of the Cartesian coordinate system in the pipeline network model space. Manually adjust the coordinates of this node to adjust the position of the general model, ensuring that the corresponding endpoints of the pipeline network model and the general model coincide. When the fixed end of the general model is connected to the end point of the pipeline model, the end node number of the pipeline is changed to N1N2N3010. The downstream pipeline nodes of the active end of the general model are numbered starting from N1N2N3930, and modeled in the manner of "inserting a new unit after the current unit". When the active end of the general model is connected to the end point of the pipeline, the end node number of the pipeline is changed to N1N2N3930. The downstream pipeline nodes of the fixed end of the general model are numbered starting from N1N2N3010, and modeled in the manner of "inserting a new unit before the current unit".

Images