Method for calculating stress of annular header of water-cooled wall of radiant waste boiler under internal and external pressure

Abstract

The invention discloses a radiation waste boiler internal and external pressure water wall annular header stress calculation method, and belongs to the field of boiler technology and coal chemical industry. The invention relates to a system for calculating the stress of an annular header of a water-cooled wall of a radiation waste heat boiler under internal and external pressure, which comprises a parameter collection module, a calculation module and a comparison and judgment module which are connected in sequence. According to the invention, the problem that an applicable strength standard is lacked in a water-cooled wall annular header (with a hole bridge) structure which is subjected to both internal pressure and external pressure is solved. By providing a new stress calculation method, the stress of the water cooling wall can be accurately calculated. According to the method, different radiation heat exchange conditions borne by the interior and the exterior of the header are considered, and the problem that the water cooling wall is heated unevenly is solved. Through the actual operation for more than ten years, the header designed by the method does not cause equipment overhaul and operation interruption due to the problems of strength or abrasion and the like, and the actual requirements are met.

Description

Technical Field

[0001] This invention relates to a method for calculating the stress of the annular header of the water-cooled wall of a radiant waste boiler subjected to internal and external pressures, belonging to the fields of boiler technology and coal chemical industry. Background Technology

[0002] A. Current problems:

[0003] Traditional water-tube boilers and shell boilers have corresponding strength standards as a guarantee. For example, the strength standard for water-tube boilers is GB / T16507.1~8-2022, and the strength standard for shell boilers is GB / T16508.1~8-2022. However, there is no corresponding strength standard for the annular header of a radiant waste boiler that is subjected to both internal and external pressure.

[0004] B. Stress calculation for annular header subjected to both internal and external pressure:

[0005] To address the lack of a standard for calculating the strength of this type of structure, this study calculates and explores the stress in the annular header of the water-cooled wall of a radiant waste boiler, which is subjected to both internal and external pressure, based on relevant data and information, with the aim of becoming part of a new strength standard.

[0006] (I) Part 3 of "Shell Boilers" (GB / T16508.1~8-2022): Design and Strength Calculation does not have a corresponding strength calculation clause.

[0007] (II) Part 4 of the standard "Water Tube Boilers" (GB / T16507.1~8-2022): Strength Calculation of Pressure-Bearing Components, the relevant content of which is as follows:

[0008] 10. Calculate the thickness

[0009] 10.2 Cylindrical body

[0010] 10.2.1 The calculated thickness of the cylindrical body shall be calculated according to formula (14) or formula (15):

[0011] δ t =pD o / (2φ min [σ]+p)……………………………………………………(14)

[0012] δ t =pD i / (2φ min [σ]-p)……………………………………………………(15)

[0013] 10.2.2 Pipes subjected to external pressure shall be checked in accordance with GB / T150.3, but the allowable stress of the material, etc., shall be implemented in accordance with this document; when D o When the thickness is not greater than 200mm, calculate the thickness (δ). t The calculated value can be 1.45 times that of formula (14) or formula (15).

[0014] The above two conditions only apply to straight cylindrical headers with perforated bridges subjected to either purely internal or purely external pressure. This structure is a water-cooled annular header with perforated bridges subjected to both internal and external pressure.

[0015] 10.6 A curved header cylinder with bends or elbows and no openings on the inner and outer arcs.

[0016] This condition also does not meet the requirements of this structure.

[0017] (III) Part 3: Design of Pressure Vessels (GB150.1~4-2011), the relevant content of which is as follows:

[0018] 3. Internal pressure cylinder and internal pressure spherical shell

[0019] 3.3 Calculation of a cylindrical cylinder

[0020] The applicable range of the formulas in this section is p. c ≤0.4[σ] t φ. The calculated thickness of the cylinder at the design temperature is calculated according to formula (3-1) or formula (3-2):

[0021] δ=p c D i / (2[σ] t φ-p c )……………………………………………………(3-1)

[0022] δ=p c D o / (2[σ] t φ+p c (3-2)

[0023] The calculated stress of the cylinder is calculated according to formula (3-3) or formula (3-4):

[0024] σ t =p c (D i +δ e ) / 2δ e …………………………………………………(3-3)

[0025] σ t =p c(D o -δ e ) / 2δ e …………………………………………………(3-4)

[0026] σ t The value should be less than or equal to [σ]. t φ

[0027] 3.4 Calculation of spherical shell (omitted)

[0028] 4. External pressure cylinder and external pressure spherical shell (omitted)

[0029] 3.3 and 3.4 are calculated based solely on internal pressure; 4 is calculated based solely on external pressure, neither of which meets the requirements of this structure.

[0030] Based on (I) to (III), it can be determined that the existing strength standards cannot meet the requirements of the new structure of the water-cooled wall annular header (with perforated bridge) which is subjected to both internal and external pressure.

[0031] In the novel structure of the water-cooled wall annular header (with perforated bridge) subjected to both internal and external pressure, 815℃ high-temperature dust-laden coal gas flows down from the top of the radiant waste boiler along the inner water-cooled wall to the bottom, where it turns between the inner and outer water-cooled walls. It then rises upward along the cavity between the inner and outer water-cooled walls and enters the inlet of the convective waste boiler through the upper outlet. As the high-temperature dust-laden coal gas flows downward, the dust gradually accumulates in the lower ash collection hopper. As the high-temperature dust-laden coal gas turns upward, the dust in the high-temperature dust-laden coal gas is separated by gravity and continues to accumulate in the ash collection hopper. The dust is then discharged according to the height of the ash collected at the bottom.

[0032] The inlet and outlet of the water-cooled walls inside and outside the radiant boiler are designed with annular headers. These headers are subjected to both internal and external pressures, operating under high temperature and high dust conditions. The working fluid pressure inside the headers is 4.11 MPa, the wall temperature is 363.5℃, the high-temperature gas pressure is 3.50 MPa, the gas temperature is 815℃, and the dust content is 10–100 g / Nm³. The radiative heat transfer conditions inside and outside the headers differ, resulting in uneven heating of the water-cooled walls. Furthermore, the differences in the dust-containing media inside and outside the headers lead to different pressures on the internal and external water-cooled walls. These factors contribute to the unique stress conditions experienced by the water-cooled walls of these headers. Since there is no corresponding national standard for strength calculations to meet the requirements of this structure, this invention proposes a solution. Summary of the Invention

[0033] This invention proposes a method for calculating the stress of the annular header of the water-cooled wall of a radiant waste boiler under internal and external pressure, in order to solve the problem that there is currently no corresponding national standard that can meet the actual needs.

[0034] A stress calculation system for the annular header of a water-cooled wall under internal and external pressure in a radiant waste boiler is provided. The system includes a parameter collection module, a calculation module, and a comparison and judgment module, which are connected sequentially.

[0035] Furthermore, the parameter collection module is used to collect relevant parameters for stress analysis of the inlet header of the water-cooled wall outside the boiler.

[0036] The calculation module is used to calculate the circumferential stress σ based on relevant parameters. θ and radial stress σ r ;

[0037] The comparison and judgment module is used to determine the circumferential stress σ. θ With radial stress σ r The difference is used to determine whether the strength meets the requirements.

[0038] Furthermore, the relevant parameters include the inner radius *a* of the inlet header of the water-cooled wall outside the radiator, the outer radius *b* of the inlet header of the water-cooled wall outside the radiator, the stress distribution variable *r* along the thickness direction, and the internal pressure *q*. a External pressure q b And allowable stress [σ]2.

[0039] Furthermore, the calculation module includes a built-in circumferential stress σ. θ The formula for calculation is:

[0040] [(b 2 / r 2 )+1]*q a / [(b 2 / a 2 )-1]-[1+(a 2 / r 2 )]*q b / [1-(a 2 / b 2 )]

[0041] It also has a built-in radial stress σ r The formula for calculation is:

[0042] -[(b 2 / r 2 )-1]*q a / [(b 2 / a 2 )-1]-[1-(a 2 / r 2 )]*q b / [1-(a 2 / b 2 )).

[0043] Furthermore, the comparison and judgment module includes a built-in judgment program used to determine the circumferential stress σ. θ With radial stress σ r Taking the difference, we get:

[0044] Δσ=σ θ -σ r

[0045] Determine whether Δσ<[σ]2 holds true. If it does, the strength meets the requirements; otherwise, the strength does not meet the requirements.

[0046] A method for calculating the stress of annular headers in a water-cooled wall of a radiant waste boiler subjected to internal and external pressures, based on the aforementioned system for calculating the stress of annular headers in a water-cooled wall of a radiant waste boiler subjected to internal and external pressures, includes the following steps:

[0047] S100. Collect relevant parameters for stress analysis of the inlet header of the water-cooled wall outside the boiler;

[0048] S200, Circumferential stress σ is calculated based on relevant parameters. θ and radial stress σ r ;

[0049] S300, based on the circumferential stress σ θ With radial stress σ r The difference is used to determine whether the strength meets the requirements.

[0050] Furthermore, in S100, the relevant parameters include the inner radius a of the inlet header of the water-cooled wall outside the radiator, the outer radius b of the inlet header of the water-cooled wall outside the radiator, the stress distribution variable r along the thickness direction, and the internal pressure q. a External pressure q b And allowable stress [σ]2.

[0051] Furthermore, in S200, the circumferential stress σ θ The formula for calculation is:

[0052] [(b 2 / r 2 )+1]*q a / [(b 2 / a 2 )-1]-[1+(a 2 / r 2 )]*q b / [1-(a 2 / b 2 )]

[0053] Radial stress σ r The formula for calculation is:

[0054] -[(b2 / r 2 )-1]*q a / [(b 2 / a 2 )-1]-[1-(a 2 / r 2 )]*q b / [1-(a 2 / b 2 )).

[0055] Furthermore, in S300, the circumferential stress σ θ With radial stress σ r Taking the difference, we get:

[0056] Δσ=σ θ -σ r

[0057] Determine whether Δσ<[σ]2 holds true. If it does, the strength meets the requirements; otherwise, the strength does not meet the requirements.

[0058] A storage medium storing a computer program, which, when executed by a processor, implements the aforementioned method for calculating the stress of a water-cooled annular header under internal and external pressure in a radiant waste boiler.

[0059] The beneficial effects of this invention are:

[0060] 1. It solves the problem of the lack of applicable strength standards in water-cooled wall annular header (with perforated bridge) structures that are subjected to both internal and external pressure.

[0061] 2. A new stress calculation method is proposed, which can accurately calculate the stress of water-cooled walls.

[0062] 3. By considering the different radiative heat transfer conditions inside and outside the header, the problem of uneven heating of the water-cooled wall was solved.

[0063] 4. The application of this method can meet the system parameter requirements and the actual operation requirements of the equipment.

[0064] 5. After more than ten years of actual operation, the header designed by this method has not caused major equipment repairs or operational interruptions due to issues such as strength or wear, winning the satisfaction of users. Attached Figure Description

[0065] Figure 1 Cross-sectional diagrams showing three forms of stress on an annular header;

[0066] Figure 2 This is a schematic diagram of the operation of an annular header subjected to internal and external pressure. Detailed Implementation

[0067] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0068] A stress calculation system for the annular header of a water-cooled wall under internal and external pressure in a radiant waste boiler is provided. The system includes a parameter collection module, a calculation module, and a comparison and judgment module, which are connected sequentially.

[0069] Specifically, the stress calculation system for the annular header of a radiant waste boiler subjected to both internal and external pressures according to the present invention includes a parameter collection module, a calculation module, and a comparison and judgment module. By collecting relevant parameters and performing calculations and comparisons, the system can accurately calculate the stress condition of the water-cooled wall, solving the problem of the lack of applicable strength standards for annular header structures of water-cooled walls subjected to both internal and external pressures. The application of this system can meet system parameter requirements and improve the reliability and stability of the equipment.

[0070] Furthermore, the parameter collection module is used to collect relevant parameters for stress analysis of the inlet header of the water-cooled wall outside the boiler.

[0071] The calculation module is used to calculate the circumferential stress σ based on relevant parameters. θ and radial stress σ r ;

[0072] The comparison and judgment module is used to determine the circumferential stress σ. θ With radial stress σ r The difference is used to determine whether the strength meets the requirements.

[0073] Specifically, the parameter collection module can accurately collect the relevant parameters required for stress analysis of the inlet header of the water-cooled wall outside the boiler; the calculation module can calculate the circumferential stress σ based on the collected parameters. θ and radial stress σ r The comparison and judgment module can compare the circumferential stress σ. θ With radial stress σ r The difference between the stress and strength is used to determine whether the strength meets the requirements. By applying this system, the stress on the water-cooled wall can be accurately calculated, and its strength can be determined to meet the requirements, thereby improving the reliability and stability of the equipment.

[0074] Furthermore, the relevant parameters include the inner radius *a* of the inlet header of the water-cooled wall outside the radiator, the outer radius *b* of the inlet header of the water-cooled wall outside the radiator, the stress distribution variable *r* along the thickness direction, and the internal pressure *q*. a External pressure qb And allowable stress [σ]2.

[0075] Specifically, the system of the present invention can accurately collect relevant parameters required for stress analysis of the inlet header of the water-cooled wall of the radiator, including the inner radius a of the inlet header of the water-cooled wall of the radiator, the outer radius b of the inlet header of the water-cooled wall of the radiator, the stress distribution variable r along the thickness direction, and the internal pressure q. a External pressure q b And allowable stress [σ]2. By collecting these parameters, the system can perform accurate stress calculations, thereby improving the reliability and stability of the equipment.

[0076] Furthermore, the calculation module includes a built-in circumferential stress σ. θ The formula for calculation is:

[0077] [(b 2 / r 2 )+1]*q a / [(b 2 / a 2 )-1]-[1+(a 2 / r 2 )]*q b / [1-(a 2 / b 2 )]

[0078] It also has a built-in radial stress σ r The formula for calculation is:

[0079] -[(b 2 / r 2 )-1]*q a / [(b 2 / a 2 )-1]-[1-(a 2 / r 2 )]*q b / [1-(a 2 / b 2 )).

[0080] Specifically, the calculation module includes a built-in circumferential stress σ. θ and radial stress σ r The calculation formulas are used to accurately calculate the circumferential and radial stresses within the header, further improving the accuracy and reliability of stress calculations and ensuring the safe operation of the equipment.

[0081] Furthermore, the comparison and judgment module includes a built-in judgment program used to determine the circumferential stress σ. θ With radial stress σ r Taking the difference, we get:

[0082] Δσ=σ θ -σ r

[0083] Determine whether Δσ<[σ]2 holds true. If it does, the strength meets the requirements; otherwise, the strength does not meet the requirements.

[0084] Specifically, the comparison and judgment module includes a built-in judgment program. This program is used to determine the circumferential stress σ. θ With radial stress σ r Taking the difference, we get Δσ = σ θ -σ r Then, it is determined whether Δσ is less than [σ]². If so, the strength meets the requirements; otherwise, the strength does not meet the requirements. This judgment procedure allows for a quick and accurate determination of whether the strength of the header meets the system parameter requirements, further ensuring the safe operation of the equipment.

[0085] A method for calculating the stress of annular headers in a water-cooled wall of a radiant waste boiler subjected to internal and external pressures, based on the aforementioned system for calculating the stress of annular headers in a water-cooled wall of a radiant waste boiler subjected to internal and external pressures, includes the following steps:

[0086] S100. Collect relevant parameters for stress analysis of the inlet header of the water-cooled wall outside the boiler;

[0087] S200, Circumferential stress σ is calculated based on relevant parameters. θ and radial stress σ r ;

[0088] S300, based on the circumferential stress σ θ With radial stress σ r The difference is used to determine whether the strength meets the requirements.

[0089] Specifically, this method is based on a stress calculation system for the annular header of a radiant waste boiler subjected to internal and external pressure. It includes steps such as collecting relevant parameters, calculating circumferential and radial stresses, and determining whether the strength meets requirements based on the stress difference. This method allows for rapid and accurate analysis of the header's stress conditions and determination of its strength requirements. This helps ensure the safe operation of the header under high temperature, high pressure, and high dust conditions, improving the reliability and stability of the equipment.

[0090] Furthermore, in S100, the relevant parameters include the inner radius a of the inlet header of the water-cooled wall outside the radiator, the outer radius b of the inlet header of the water-cooled wall outside the radiator, the stress distribution variable r along the thickness direction, and the internal pressure q. a External pressure q b And allowable stress [σ]2.

[0091] Specifically, in S100, by collecting relevant parameters of the inlet header of the water-cooled wall of the boiler, including inner and outer radii, stress distribution variables, inner and outer pressures, and allowable stresses, a comprehensive understanding of the header's geometry and stress conditions can be obtained. This helps to more accurately calculate circumferential and radial stresses, and in S300, it can be determined whether the header's strength meets the requirements. This method improves the design accuracy and calculation precision of the header, ensuring the safe operation of the equipment under high temperature, high pressure, and high dust conditions.

[0092] Furthermore, in S200, the circumferential stress σ θ The formula for calculation is:

[0093] [(b 2 / r 2 )+1]*q a / [(b 2 / a 2 )-1]-[1+(a 2 / r 2 )]*q b / [1-(a 2 / b 2 )]

[0094] Radial stress σ r The formula for calculation is:

[0095] -[(b 2 / r 2 )-1]*q a / [(b 2 / a 2 )-1]-[1-(a 2 / r 2 )]*q b / [1-(a 2 / b 2 )).

[0096] Specifically, in S200, the stress distribution of the header under internal and external pressure can be accurately calculated using formulas for circumferential and radial stress. The formula for circumferential stress considers parameters such as the header's inner and outer radii, stress distribution variables, and internal and external pressures, enabling a more precise calculation of the magnitude of the circumferential stress. The formula for radial stress also comprehensively considers the header's geometric parameters and internal and external pressures, accurately calculating the distribution of radial stress. This method provides a comprehensive understanding of the stress state inside and outside the header, offering accurate data for header design and strength assessment. This helps ensure the header's ability to withstand internal and external pressures during operation, improving the safety and reliability of the equipment.

[0097] Furthermore, in S300, the circumferential stress σ θ With radial stress σr Taking the difference, we get:

[0098] Δσ=σ θ -σ r

[0099] Determine whether Δσ<[σ]2 holds true. If it does, the strength meets the requirements; otherwise, the strength does not meet the requirements.

[0100] Specifically, in S300, the difference between circumferential and radial stress, Δσ, is calculated and compared with a given strength standard [σ]² to determine whether the header's strength meets the requirements. If Δσ is less than [σ]², the header's strength meets the system parameter requirements and can safely withstand internal and external pressures; if Δσ is greater than or equal to [σ]², the header's strength does not meet the requirements and further design or improvement is needed. This method allows for timely assessment of the header's strength, ensuring that insufficient strength does not occur during equipment operation and improving equipment reliability and safety.

[0101] A storage medium storing a computer program, which, when executed by a processor, implements the aforementioned method for calculating the stress of a water-cooled annular header under internal and external pressure in a radiant waste boiler.

[0102] Specifically, this invention provides a storage medium storing a computer program. When the computer program is executed by a processor, it can implement the stress calculation method for the annular header of the radiant waste boiler under internal and external pressure, as described above. The use of this storage medium allows for convenient application of this calculation method in practical engineering, improving the accuracy and efficiency of the calculations and providing strong support for the design and improvement of radiant waste boiler headers.

[0103] In practical applications, we can take the limit value and let r = a or r = b to find out whether the strength meets the requirements under the two limit conditions.

Claims

1. A system for calculating the stress of a water-cooled annular header in a radiant waste boiler subjected to internal and external pressures, characterized in that, The stress calculation system for the annular header of the water-cooled wall of the radiant waste boiler subjected to internal and external pressure includes a parameter collection module, a calculation module, and a comparison and judgment module, which are connected in sequence.

2. The stress calculation system for the annular header of a radiant waste boiler subjected to internal and external pressures as described in claim 1, characterized in that, The parameter collection module is used to collect relevant parameters for stress analysis of the inlet header of the water-cooled wall outside the boiler. The calculation module is used to calculate the circumferential stress σ based on the relevant parameters. θ and radial stress σ r ; The comparison and judgment module is used to determine the circumferential stress σ. θ With radial stress σ r The difference is used to determine whether the strength meets the requirements.

3. The stress calculation system for the annular header of a radiant waste boiler subjected to internal and external pressures as described in claim 2, characterized in that, The relevant parameters include the inner radius *a* of the inlet header of the outer water-cooled wall of the radiator, the outer radius *b* of the inlet header of the outer water-cooled wall of the radiator, the stress distribution variable *r* along the thickness direction, and the internal pressure *q*. a External pressure q b And allowable stress [σ]2.

4. The stress calculation system for the annular header of a radiant waste boiler subjected to internal and external pressures as described in claim 3, characterized in that, The calculation module includes a built-in circumferential stress σ. θ The formula for calculation is: [(b 2 / r 2 )+1]*q a / [(b 2 / a 2 )-1]-[1+(a 2 / r 2 )]*q b / [1-(a 2 / b 2 )] It also has a built-in radial stress σ r The formula for calculation is: -[(b 2 / r 2 )-1]*q a / [(b 2 / a 2 )-1]-[1-(a 2 / r 2 )]*q b / [1-(a 2 / b 2 )]。 5. The stress calculation system for the annular header of a radiant waste boiler subjected to internal and external pressures as described in claim 4, characterized in that, The comparison and judgment module includes a built-in judgment program, which is used to determine the circumferential stress σ. θ With radial stress σ r Taking the difference, we get: Ds = s θ -s r Determine whether Δσ<[σ]2 holds true. If it does, the strength meets the requirements; otherwise, the strength does not meet the requirements.

6. A method for calculating the stress of annular headers on water-cooled walls of a radiant waste boiler subjected to internal and external pressure, based on the stress calculation system for annular headers on water-cooled walls of a radiant waste boiler subjected to internal and external pressure as described in any one of claims 1-5, characterized in that, The method for calculating the stress of the annular header of the water-cooled wall of the radiation waste boiler under internal and external pressure includes the following steps: S100. Collect relevant parameters for stress analysis of the inlet header of the water-cooled wall outside the boiler; S200, Calculate the circumferential stress σ based on the relevant parameters. θ and radial stress σ r ; S300, based on the circumferential stress σ θ With radial stress σ r The difference is used to determine whether the strength meets the requirements.

7. The method for calculating the stress of the annular header of a radiant waste boiler under internal and external pressure as described in claim 6, characterized in that, In S100, the relevant parameters include the inner radius a of the inlet header of the water-cooled wall of the radiator, the outer radius b of the inlet header of the water-cooled wall of the radiator, the stress distribution variable r along the thickness direction, and the internal pressure q. a External pressure q b And allowable stress [σ]2.

8. The method for calculating the stress of the annular header of a radiant waste boiler under internal and external pressure as described in claim 7, characterized in that, In S200, the circumferential stress σ θ The formula for calculation is: [(b 2 / r 2 )+1]*q a / [(b 2 / a 2 )-1]-[1+(a 2 / r 2 )]*q b / [1-(a 2 / b 2 )] The radial stress σ r The formula for calculation is: -[(b 2 / r 2 )-1]*q a / [(b 2 / a 2 )-1]-[1-(a 2 / r 2 )]*q b / [1-(a 2 / b 2 )]。 9. The method for calculating the stress of the annular header of a radiant waste boiler under internal and external pressure as described in claim 8, characterized in that, In S300, the circumferential stress σ θ With radial stress σ r Taking the difference, we get: Ds = s θ -s r Determine whether Δσ<[σ]2 holds true. If it does, the strength meets the requirements; otherwise, the strength does not meet the requirements.

10. A storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the stress calculation method for the annular header of the water-cooled wall of a radiation waste boiler under internal and external pressure, as described in any one of claims 6-9.

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