CN111177953B - Method for calculating strength of tube plate system of floating head heat exchanger with expansion joint at tail end - Google Patents

Method for calculating strength of tube plate system of floating head heat exchanger with expansion joint at tail end Download PDF

Info

Publication number
CN111177953B
CN111177953B CN202010165981.0A CN202010165981A CN111177953B CN 111177953 B CN111177953 B CN 111177953B CN 202010165981 A CN202010165981 A CN 202010165981A CN 111177953 B CN111177953 B CN 111177953B
Authority
CN
China
Prior art keywords
tube plate
sigma
floating
expansion joint
end tube
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.)
Active
Application number
CN202010165981.0A
Other languages
Chinese (zh)
Other versions
CN111177953A (en
Inventor
朱国栋
谢铁军
谢国山
史进
钱才富
何萌
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.)
China Special Equipment Inspection and Research Institute
Original Assignee
China Special Equipment Inspection and Research Institute
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 China Special Equipment Inspection and Research Institute filed Critical China Special Equipment Inspection and Research Institute
Publication of CN111177953A publication Critical patent/CN111177953A/en
Application granted granted Critical
Publication of CN111177953B publication Critical patent/CN111177953B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Abstract

The inventionThe method for calculating the strength of the tube plate system of the floating head heat exchanger with the expansion joint at the tail end comprises the following steps: s1, respectively setting the thickness and the diameter of the fixed end tube plate and the floating end tube plate; s2, selecting the materials of the fixed end tube plate and the floating end tube plate respectively, and checking the allowable stress [ sigma ] of the fixed end tube plate material according to the standard1]Allowable stress [ sigma ] of floating end pipe plate material2](ii) a S3, selecting the type, size and specification of the expansion joint; s4, calculating the corresponding bending stress value sigma of the fixed end tube plate through a seven-element linear equation systempBending stress value corresponding to floating end pipe plate
Figure DDA0002407469100000011
And heat exchange tube axial stress sigmat(ii) a S5, compare sigmapAnd [ sigma ]1]And comparing
Figure DDA0002407469100000012
And [ sigma ]2](ii) a S5, calculating axial stress sigma of heat exchange tubetRespectively comparing σtAnd allowable stress [ sigma ] of heat exchange tubet]Or critical compressive stress sigmacr. The calculation method of the invention considers the axial rigidity of the expansion joint and the pressure influence of the inner cavity, and can reasonably determine the materials, the thicknesses and the diameters of the fixed end tube plate and the floating end tube plate and reasonably evaluate the strength and the stability of the heat exchange tube.

Description

Method for calculating strength of tube plate system of floating head heat exchanger with expansion joint at tail end
Technical Field
The invention relates to the technical field of shell-and-tube heat exchangers, in particular to a tube plate system strength calculation method of a floating head heat exchanger with an expansion joint at the tail end.
Background
The shell-and-tube heat exchanger is typically a pressure vessel, accounting for about 30% of petrochemical plant equipment. The shell-and-tube heat exchanger is divided into a U-shaped tube heat exchanger, a fixed tube plate heat exchanger and a floating head heat exchanger, wherein the floating head heat exchanger is mainly applied to the conditions that the temperature difference of the shell-and-tube pass is large and the internal medium is easy to scale.
The conventional floating head heat exchanger mainly comprises the following components: the fixed end tube plate, the floating end tube plate and the heat exchange tube bundle are connected with each other to form a tube plate system. The tube plate system and the shell side cylinder are connected only through the fixed end tube plate, the floating tube plate is in a free state in the axial direction of the heat exchanger, so that the temperature difference stress of the tube plate system and the shell side cylinder can be released. When the tube pass has the occasion with large inter-pass temperature difference, the conventional floating head heat exchanger can not meet the requirement due to overlarge inter-pass temperature difference stress, and at the moment, the floating head heat exchanger with the expansion joint at the tail end is generally adopted.
There are two types of calculation routes for current heat exchangers: (1) theoretical analysis method of plate shell; (2) finite element numerical method. The existing plate shell theoretical analysis and calculation method is specific to a conventional floating head heat exchanger, and the floating head heat exchanger with an expansion joint at the tail end causes great deviation, great waste or potential safety hazard.
A reasonable analytic calculation method is not found in the floating head heat exchanger with the expansion joint at the tail end.
Disclosure of Invention
In order to solve the technical problems, a method for calculating the tube plate system strength of the floating head heat exchanger with the expansion joint at the tail end is provided, wherein the tube plate system strength is calculated by respectively checking and calculating the tube plates of the fixed end and the floating end with different thicknesses, different materials and different diameters by considering the axial rigidity of the expansion joint and the pressure influence of an inner cavity.
A method for calculating the strength of a tube plate system of a floating head heat exchanger with an expansion joint at the tail end comprises the following steps:
s1, respectively selecting materials of a fixed end tube plate and a floating end tube plate of the floating head heat exchanger according to the medium condition, and setting the thickness of the fixed end tube plate of the floating head heat exchanger to be delta1Thickness delta of floating end tube sheet2And determining allowable stress value [ sigma ] of fixed end tube plate1]And allowable stress value [ sigma ] of floating tube plate2](ii) a Determining the size and the material of the heat exchange tube;
s2, setting the diameter of a fixed end tube plate and the diameter of a floating end tube plate of the floating head heat exchanger according to the structural requirements;
s3, selecting the type, specification and size of the expansion joint;
s4, calculating the radial or circumferential bending moment M (x) to which the fixed end tube plate is subjected and the radial or circumferential bending moment M to which the floating end tube plate is subjectedf1(x)；
S5, mixing M (x) and M obtained in S4f1(x) Respectively carry into stress equation
Figure BDA0002407469080000021
In the above method, the respective bending stress values σ on the upper and lower surfaces of the fixed-end tube sheet are calculated under the condition of setting the thickness of the tube sheetpCorresponding bending stress values on the upper and lower surfaces of the floating end tube plate
Figure BDA0002407469080000024
Wherein μ is a bending reduction coefficient;
s6, compare sigmapAnd [ sigma ]1]And comparing
Figure BDA0002407469080000022
And [ sigma ]2]；
If σpGreater than 1.5[ sigma ]1]Or
Figure BDA0002407469080000023
Greater than 1.5[ sigma ]2]Then, steps S1-S5 are repeated to increase delta1Or delta2Either replacing the material of the fixed end tube plate or the floating end tube plate, or adjusting the size and dimension of the expansion joint until sigmapLess than 1.5[ sigma ]1]And is
Figure BDA00024074690800000310
Less than 1.5[ sigma ]2]。
Note that if σ ispLess than 1.5[ sigma ]1]And is
Figure BDA0002407469080000031
Less than 1.5[ sigma ]2]The design requirements are met. In step S3, the expansion joint is a flexible expansion joint, including a U-shaped expansion joint and an Ω expansion joint; the invention can be used to calculate the axial stiffness of a U-shaped expansion joint, and the stiffness of the expansion joint can be input for other types of flexible expansion joints.
A plurality of heat exchange tubes are arranged between the fixed tube plate and the floating tube plate, and after the step S6, the method further comprises:
s7, determining the material of the heat exchange tube, and determining the allowable stress value [ sigma ] of the heat exchange tube according to the material of the heat exchange tubet]And axial critical pressure stress [ sigma ] of heat exchange tubecr]；
Calculating the axial stress sigma of each heat exchange tubet；
At σt>When 0, when σt<[σt]The design requirements are met;
at σt<0, when σt|<[σcr]And the design requirements are met.
Step S4 further includes: respectively calculating the radial bending moment M borne by the fixed end tube plater(x) And circumferential bending moment Mθ(x) Radial bending moment born by floating end tube plate
Figure BDA0002407469080000032
And circumferential bending moment
Figure BDA0002407469080000033
Step S5 further includes: according to Mr(x)、Mθ(x)、
Figure BDA0002407469080000034
And
Figure BDA0002407469080000035
respectively calculating the radial stress sigma of the fixed end tube plateriCircumferential stress sigma of fixed end tube plateθiRadial stress of floating end tube plate
Figure BDA0002407469080000036
And circumferential stress of floating end tube sheet
Figure BDA0002407469080000037
Step S6 also includes thatriAnd σθiAre respectively related to [ sigma ]1]Making a comparison of
Figure BDA0002407469080000038
And
Figure BDA0002407469080000039
are respectively related to [ sigma ]2]Respectively comparing the two and finally determining the thickness delta of the fixed tube plate1And the thickness delta of the floating tube plate2。
The floating head heat exchanger calculation includes expansion joint internal pressure and axial rigidity influence, and the step S4 further includes the following steps: calculating the axial displacement relation of the heat exchange tube by using the following formula:
displacement at the fixed end
Figure BDA0002407469080000041
Displacement at the floating end:
Figure BDA0002407469080000042
and determining the relationship between the bending moment and the displacement of the tube plate according to the following formula:
fixing a tube plate:
Figure BDA0002407469080000043
Figure BDA0002407469080000044
floating end tube plate
Figure BDA0002407469080000045
Figure BDA0002407469080000046
Wherein C1, C2, C3 and C4 are unknown constants, ber (x), bei (x) are Thomson functions, D is bending rigidity of fixed end tube plate, and D isf1Bending rigidity of the floating end tube plate, eta is the weakening coefficient of the bending rigidity of the tube plate opening area, f1(x)、f2(x)、f3(x)、f4(x) Is an expression taking x as variable, v is the Poisson's ratio of the tube sheet material, MrRadial bending moment M of fixed end tube plateθIs the circumferential bending moment of the fixed end tube plate,
Figure BDA0002407469080000047
radial bending moment of the floating end tube plate,
Figure BDA0002407469080000048
The circumferential bending moment of the floating end tube plate is shown, and k is a dimensionless parameter.
In step S4, the radial bending moment M experienced by the fixed tube sheet is calculated as followsr(x) And circumferential bending moment Mθ(x) Radial bending moment borne by the floating tube plate
Figure BDA0002407469080000049
And circumferential bending moment
Figure BDA00024074690800000410
S401, according to an equation set:
Figure BDA0002407469080000051
Figure BDA0002407469080000052
Figure BDA0002407469080000053
Figure BDA0002407469080000054
Figure BDA0002407469080000055
Figure BDA0002407469080000056
Figure BDA0002407469080000057
a seven-element linear matrix equation set is established according to the following formula:
Figure BDA0002407469080000058
calculating an unknown quantity matrix according to the equation set:
Figure BDA0002407469080000059
wherein, PdtEquivalent pressure, R, to which the floating tube sheet is subjectedtIs one half of Dt, f1(K)、f2(K) For expressions with K as a variable, MRFor fixing the radial bending moment, M, of the peripheral non-laying zone of the tube sheettIn order to fix the radial bending moment of the central pipe distribution area of the pipe plate,
Figure BDA0002407469080000061
the radial bending moment of the peripheral non-distribution pipe area of the floating pipe plate,
Figure BDA0002407469080000062
radial bending moment for the central tube laying area of the floating tube plate, KtR、Ktt、Ktp、 KtV、KRR、KRp、Kf、KRt、KRVIn order to fix the flexibility coefficient of the tube-not-laid region at the periphery of the tube plate,
Figure BDA0002407469080000063
Figure BDA0002407469080000064
the flexibility coefficient of the non-tube distribution area at the periphery of the floating tube plate is rhot＝RtR (ratio of equivalent circle radius of tube plate area at fixed end to support radius of tube plate), R is support radius of tube plate at fixed end, R isf1To support the radius for the floating end tube sheet,
Figure BDA0002407469080000065
the ratio of the equivalent circle radius of the floating end tube plate distribution area to the tube plate support radius;
s402, substituting the result obtained in the step S401 into an equation to respectively calculate the bending moment of each fixed end pipe plate distribution area and the bending moment of each floating end pipe plate distribution area:
fixing end:
Figure BDA0002407469080000066
Figure BDA0002407469080000067
floating end:
Figure BDA0002407469080000068
Figure BDA0002407469080000069
wherein, c1、c2、c4To calculate the coefficients.
P is calculated as followsdt：
Pdt＝H0+H1c1+H2c2；
Wherein H0The corrected value of the pressure area is obtained; h1、H2The deformation correction value of the tube plate is used;
according to the formula respectively
Figure BDA0002407469080000071
Formula (II)
Figure BDA0002407469080000072
And formula
Figure BDA0002407469080000073
Calculate H0、H1And H2。KexIs the axial stiffness of the expansion joint;
Figure BDA0002407469080000074
displacement caused by the pressure in the inner cavity of the expansion joint.
K is calculated according to the following formulaexAnd
Figure BDA0002407469080000075
Figure BDA0002407469080000076
Figure BDA0002407469080000077
Figure BDA0002407469080000078
Figure BDA0002407469080000079
step S7 further includes: substituting the unknowns C1 and C2 obtained in the step S401 into the stress equation of the heat exchange tube
Figure BDA00024074690800000710
In obtaining the stress sigma of each heat exchange tubet。
The method for calculating the strength of the tube plate system of the floating head heat exchanger with the expansion joint at the tail end not only considers the influence of the axial rigidity of the expansion joint at the tail end and the pressure of the inner cavity of the expansion joint on the tube plate system, but also can respectively select the materials of the fixed end tube plate and the floating end tube plate and respectively determine the thicknesses of the fixed end tube plate and the floating end tube plate, so that the materials of the fixed end tube plate and the floating end tube plate can be different, the thicknesses and the diameters can be different, the application range of the floating head heat exchanger is enlarged, the inner cavity pressure parameter and the axial rigidity influence parameter substituted by the expansion joint are substituted into the determination process of the thickness of the tube plate, and the influence of the expansion joint on the strength calculation of the tube plate system is considered in the calculation process. The method not only ensures the calculation reliability of the floating head heat exchanger with the expansion joint at the tail end, but also can reasonably determine the materials, the thicknesses and the diameters of the fixed end tube plate and the floating end tube plate.
The calculation method provided by the invention can calculate the tube plate strength of the floating head heat exchanger with the expansion joint at the tail end and the strength and stability of the heat exchange tube, is suitable for different materials of the fixed end tube plate and the floating end tube plate, and can also have different thicknesses and diameters, so that the application range of the floating head heat exchanger is enlarged, and the inner cavity pressure parameter and the axial rigidity influence parameter substituted by the expansion joint are substituted into the determination process of the tube plate thickness, so that the materials, the thicknesses and the diameters of the fixed end tube plate and the floating end tube plate are reasonably determined, and the strength and the stability of the heat exchange tube are reasonably evaluated.
Drawings
FIG. 1 is a structural section view of a floating head heat exchanger with an expansion joint at the tail end;
FIG. 2 is a floating head heat exchanger mechanical model symbol;
FIG. 3 is a graph comparing tube sheet stress at various locations at shell side pressure;
FIG. 4 is a graph comparing stress at various locations of tube sheet stress at tube side pressure;
FIG. 5 is a graph comparing axial stress of heat exchange tubes at tube side and shell side pressures;
FIG. 6 is a graph comparing tube sheet stresses at shell side pressure with and without an expansion joint;
FIG. 7 is a graph comparing tube sheet stress at tube side pressure with and without an expansion joint.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
FIG. 1 is a sectional view of a floating head heat exchanger with an expansion joint at the tail end;
fig. 2 is a floating head heat exchanger mechanical model symbol.
When the floating head heat exchanger is designed, the calculation of the tube plate strength and the tube bundle stress is an examination project which must be carried out by the heat exchanger, and the formula calculation in the prior art is a main design means. The structure of the expansion joint at the tail end is not considered in the calculation of the existing formula, and the thickness of the fixed end tube plate and the floating end tube plate is determined on the premise that the materials and the thickness of the fixed end tube plate and the floating end tube plate are the same, so that the problem that the application range of the floating-head heat exchanger is too small is caused. For the calculation of the asymmetric structure floating head heat exchanger with the expansion joint at the tail end, no simple and accurate solution is found.
The invention considers the deformation coordination relations of the tube plate, the tube bundle, the expansion joint and the like, and provides the tube plate under pressure and the tube bundle strength calculation based on the plate shell theory analytic solution.
The invention provides a method for calculating the strength of a tube plate system of a floating head heat exchanger with an expansion joint at the tail end, which comprises the following steps:
s1, respectively selecting materials of a fixed end tube plate and a floating end tube plate of the floating head heat exchanger according to the medium condition, and setting the thickness of the fixed end tube plate of the floating head heat exchanger to be delta1Thickness delta of floating end tube sheet2And determining allowable stress value [ sigma ] of fixed end tube plate1]And allowable stress value [ sigma ] of floating tube plate2](ii) a Determining the size and the material of the heat exchange tube;
s2, setting the diameter of a fixed end tube plate and the diameter of a floating end tube plate of the floating head heat exchanger according to the structural requirements;
s3, selecting the type, specification and size of the expansion joint;
s4, calculating the radial or circumferential bending moment M (x) to which the fixed end tube plate is subjected and the radial or circumferential bending moment M to which the floating end tube plate is subjectedf1(x)；
S5, mixing M (x) and M obtained in S4f1(x) Respectively carry into stress equation
Figure BDA0002407469080000091
In the above method, the respective bending stress values σ on the upper and lower surfaces of the fixed-end tube sheet are calculated under the condition of setting the thickness of the tube sheetpCorresponding bending stress values on the upper and lower surfaces of the floating end tube plate
Figure BDA0002407469080000092
Wherein μ is a bending reduction coefficient;
s6, compare sigmapAnd [ sigma ]1]And comparing
Figure BDA0002407469080000101
And [ sigma ]2]；
If σpGreater than 1.5[ sigma ]1]Or
Figure BDA0002407469080000102
Greater than 1.5[ sigma ]2]Then, steps S1-S5 are repeated to increase delta1Or delta2Either replacing the material of the fixed end tube plate or the floating end tube plate, or adjusting the size and dimension of the expansion joint until sigmapLess than 1.5[ sigma ]1]And is
Figure BDA0002407469080000103
Less than 1.5[ sigma ]2]。；
Note that if σ ispLess than 1.5[ sigma ]1]And is
Figure BDA0002407469080000104
Less than 1.5[ sigma ]2]The design requirements are met. In step S3, the expansion joint is a flexible expansion joint, including a U-shaped expansion joint and an Ω expansion joint; the invention can be used to calculate the axial stiffness of a U-shaped expansion joint, and the stiffness of the expansion joint can be input for other types of flexible expansion joints.
A plurality of heat exchange tubes are arranged between the fixed tube plate and the floating tube plate, and after the step S6, the method further comprises:
s7, determining the material of the heat exchange tube according to the medium, and determining the allowable stress value [ sigma ] of the heat exchange tube according to the material of the heat exchange tubet]And axial critical pressure stress [ sigma ] of heat exchange tubecr]；
Calculating the axial stress sigma of each heat exchange tubetAnd will betAre respectively related to [ sigma ]t]And σcrComparing;
at σt>When 0, when σt<[σt]The design requirements are met;
at σt<0, when σt|<[σcr]And the design requirements are met.
More specifically:
step S4 further includes: respectively calculating the radial bending moment M borne by the fixed end tube plater(x) And circumferential bending moment Mθ(x) Radial bending moment born by floating end tube plate
Figure BDA0002407469080000105
And circumferential bending moment
Figure BDA0002407469080000106
Step S5 further includes: according to Mr(x)、Mθ(x)、
Figure BDA0002407469080000107
And
Figure BDA0002407469080000108
respectively calculating the radial stress sigma of the fixed end tube plateriCircumferential stress sigma of fixed end tube plateθiRadial stress of floating end tube plate
Figure BDA0002407469080000109
And circumferential stress of floating end tube sheet
Figure BDA00024074690800001010
Step S6 also includes thatriAnd σθiAre respectively related to [ sigma ]1]Making a comparison of
Figure BDA00024074690800001011
And
Figure BDA00024074690800001012
are respectively related to [ sigma ]2]Respectively, and determining the thickness delta of the fixed tube plate1And the thickness delta of the floating tube plate2。
The floating head heat exchanger comprises an expansion joint, and the step S4 further comprises the following steps: calculating the axial displacement relation of the heat exchange tube by using the following formula:
displacement at the fixed end
Figure BDA0002407469080000111
Displacement at the floating end:
Figure BDA0002407469080000112
and determining the relationship between the bending moment and the displacement of the tube plate according to the following formula:
fixing a tube plate:
Figure BDA0002407469080000113
Figure BDA0002407469080000114
floating end tube plate
Figure BDA0002407469080000115
Figure BDA0002407469080000116
Description of the symbols:
c1, C2, C3, C4 are unknown constants;
ber (x), bei (x) are thomson functions;
d is the bending rigidity of the fixed end tube plate;
Df1bending rigidity of the floating end tube plate;
eta is the weakening coefficient of bending rigidity of the opening area of the tube plate;
f1(x)、f2(x)、f3(x)、f4(x) Is an expression with x as a variable;
ν is the poisson ratio of the tube sheet material;
Mrradial bending moment of the fixed end tube plate;
Mθthe circumferential bending moment is the circumferential bending moment of the fixed end tube plate;
Figure BDA0002407469080000121
the radial bending moment of the floating end tube plate is adopted;
Figure BDA0002407469080000122
the circumferential bending moment of the floating end tube plate is adopted;
k is a dimensionless parameter.
In step S4, the radial bending moment M borne by the fixed tube plate is calculated and calculated according to the following stepsr(x) And circumferential bending moment Mθ(x) Calculating the radial bending moment born by the floating tube plate
Figure BDA0002407469080000123
And circumferential bending moment
Figure BDA0002407469080000124
S401, establishing a relational expression:
Figure BDA0002407469080000125
Figure BDA0002407469080000126
Figure BDA0002407469080000127
Figure BDA0002407469080000128
Figure BDA0002407469080000129
Figure BDA00024074690800001210
Figure BDA0002407469080000131
a seven-element linear matrix equation set is established according to the following formula:
Figure BDA0002407469080000132
calculating an unknown quantity matrix according to the equation set:
Figure BDA0002407469080000133
description of the symbols:
Pdtthe equivalent pressure to which the floating tube plate is subjected;
Rtis one half of Dt;
f1(K)、f2(K) is an expression with K as a variable;
MRthe radial bending moment of the peripheral non-laying pipe area of the fixed pipe plate;
Mtthe radial bending moment of the central pipe distribution area of the fixed pipe plate;
Figure BDA0002407469080000134
the radial bending moment of the peripheral non-distribution pipe area of the floating pipe plate;
Figure BDA0002407469080000136
the radial bending moment of the central layout area of the floating tube plate is obtained;
KtR、Ktt、Ktp、KtV、KRR、KRp、Kf、KRt、KRVthe flexibility coefficient of the non-tube distribution area at the periphery of the fixed tube plate;
Figure BDA0002407469080000135
the flexibility coefficient of the peripheral non-pipe distribution area of the floating pipe plate;
ρt＝Rtthe ratio of the equivalent circle radius of the tube plate distribution area of the fixed end tube plate to the support radius of the tube plate;
r is the supporting radius of the fixed end tube plate;
Rf1supporting a radius for the floating end tube sheet;
Figure BDA0002407469080000141
the ratio of the equivalent circle radius of the floating end tube plate distribution area to the tube plate support radius;
s402, substituting the result obtained in the step S401 into an equation to respectively calculate the bending moment of each fixed end pipe plate distribution area and the bending moment of each floating end pipe plate distribution area:
fixing end:
Figure BDA0002407469080000142
Figure BDA0002407469080000143
floating end:
Figure BDA0002407469080000144
Figure BDA0002407469080000145
wherein, c1、c2、c4To calculate the coefficients.
Calculate P bydt：
Pdt＝H0+H1c1+H2c2；
Wherein H0The corrected value of the pressure area is obtained; h1、H2The deformation correction value of the tube plate is used;
according to the formula respectively
Figure BDA0002407469080000146
Formula (II)
Figure BDA0002407469080000147
And formula
Figure BDA0002407469080000148
Calculate H0、H1And H2。KexIs the axial stiffness of the expansion joint;
Figure BDA0002407469080000149
displacement caused by the pressure in the inner cavity of the expansion joint.
K is calculated according to the following formulaexAnd
Figure BDA00024074690800001410
Figure BDA0002407469080000151
Figure BDA0002407469080000152
Figure BDA0002407469080000153
Figure BDA0002407469080000154
step S7 further includes: substituting the unknowns C1 and C2 obtained in the step S401 into the stress equation of the heat exchange tube
Figure BDA0002407469080000155
In obtaining the stress sigma of each heat exchange tubet。
FIGS. 3 to 7 are graphs comparing the tube sheet thickness obtained by the calculation method of the present invention with the results of finite element calculation, wherein DBF represents the calculation method of the present invention, DBA represents the results of finite element calculation, and other symbols are shown in the symbols. Fig. 3-5 show that the calculation results are in good agreement with finite element calculations. Fig. 6-7 show that, for both shell side and tube side pressures, the tube sheet stress levels are lower with the expansion joint than without, and that a thinner tube sheet thickness would be required, as calculated by this method, resulting in a cost savings.
The method for calculating the strength of the tube plate system of the floating head heat exchanger with the expansion joint at the tail end provided by the invention considers the axial rigidity and the inner cavity pressure influence of the expansion joint, can respectively select the materials of the fixed end tube plate and the floating end tube plate, and respectively determines the thicknesses of the fixed end tube plate and the floating end tube plate, so that the materials of the fixed end tube plate and the floating end tube plate can be different, the thicknesses and the diameters can also be different, the application range of the floating head heat exchanger is enlarged, the deviation and the potential safety hazard brought by the expansion joint are avoided, and the materials, the thicknesses and the diameters of the fixed end tube plate and the floating end tube plate are reasonably determined on the premise of ensuring the reliability of the floating head heat exchanger.
The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the present invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims (1)

1. A method for calculating the strength of a tube plate system of a floating head heat exchanger with an expansion joint at the tail end is characterized by comprising the following steps: the method comprises the following steps:
according to formula Pdt＝H0+H1c1+H2c2 pressure P to which the tube sheet is subjecteddCorrected and then according to the corrected pressure PdtCorrecting the thickness of the tube sheet, wherein PdFor the pressure of the current calculated condition, PdtEquivalent pressure to which the tube sheet is subjected, H0The corrected value of the pressure area is obtained; h1、H2The deformation correction value of the tube plate is used;
according to the formula respectively
Figure FDA0003397191320000011
Formula (II)
Figure FDA0003397191320000012
And formula
Figure FDA0003397191320000013
Calculate H0、H1And H2；
Wherein KexIs the axial stiffness of the expansion joint;
Figure FDA0003397191320000014
displacement caused by the pressure in the inner cavity of the expansion joint;
k is calculated according to the following formulaexAnd
Figure FDA0003397191320000015
Figure FDA0003397191320000016
Figure FDA0003397191320000017
Figure FDA0003397191320000018
CN202010165981.0A 2019-07-24 2020-03-11 Method for calculating strength of tube plate system of floating head heat exchanger with expansion joint at tail end Active CN111177953B (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN201910673376.1A CN110532611A (en) 2019-07-24 2019-07-24 The modification method of floating head heat exchanger tube plate thickness of the tail end with expansion joint
CN2019106733761 2019-07-24

Publications (2)

Publication Number Publication Date
CN111177953A CN111177953A (en) 2020-05-19
CN111177953B true CN111177953B (en) 2022-01-11

Family

ID=68661315

Family Applications (2)

Application Number Title Priority Date Filing Date
CN201910673376.1A Pending CN110532611A (en) 2019-07-24 2019-07-24 The modification method of floating head heat exchanger tube plate thickness of the tail end with expansion joint
CN202010165981.0A Active CN111177953B (en) 2019-07-24 2020-03-11 Method for calculating strength of tube plate system of floating head heat exchanger with expansion joint at tail end

Family Applications Before (1)

Application Number Title Priority Date Filing Date
CN201910673376.1A Pending CN110532611A (en) 2019-07-24 2019-07-24 The modification method of floating head heat exchanger tube plate thickness of the tail end with expansion joint

Country Status (1)

Country Link
CN (2) CN110532611A (en)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110532611A (en) * 2019-07-24 2019-12-03 中国特种设备检测研究院 The modification method of floating head heat exchanger tube plate thickness of the tail end with expansion joint
CN114818297B (en) * 2022-04-15 2023-05-09 中国特种设备检测研究院 Straight-section outer guide cylinder safety evaluation method, heat exchanger correction method and system
CN116244849B (en) * 2023-01-31 2023-11-17 中国特种设备检测研究院 Optimal design method and system for incomplete pipe-distribution floating head heat exchanger

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SE518089C2 (en) * 1999-10-26 2002-08-27 Tetra Laval Holdings & Finance Device at a tube heat exchanger
JP3631406B2 (en) * 1999-12-28 2005-03-23 株式会社日本触媒 Multitubular reactor for catalytic gas phase oxidation reactions.
CN105091634A (en) * 2014-05-21 2015-11-25 航天长征化学工程股份有限公司 Baffle rod type heat exchanger with built-in expansion joint
CN105004202B (en) * 2015-07-03 2018-09-21 合肥通用机械研究院有限公司 A kind of heat exchanger of composite structure
CN107944092A (en) * 2017-11-01 2018-04-20 常州大学 A kind of band two-tube double tube plate heat exchanger tube to plate welding method of expansion joint
CN109241642B (en) * 2018-09-18 2021-08-31 中国特种设备检测研究院 Method for judging instability bearing capacity of shell-and-tube heat exchanger
CN110619141B (en) * 2019-07-24 2021-09-07 中国特种设备检测研究院 Calculation method for tube plate and tube bundle of floating head heat exchanger
CN110532611A (en) * 2019-07-24 2019-12-03 中国特种设备检测研究院 The modification method of floating head heat exchanger tube plate thickness of the tail end with expansion joint

Also Published As

Publication number Publication date
CN111177953A (en) 2020-05-19
CN110532611A (en) 2019-12-03

Similar Documents

Publication Publication Date Title
CN111177953B (en) Method for calculating strength of tube plate system of floating head heat exchanger with expansion joint at tail end
Moss Pressure vessel design manual
CN106439313A (en) Multi-petal inclined-surface hoop and pipe connector thereof
US20060082154A1 (en) Connection of two pipes and sealing ring for the connection
CN110619141B (en) Calculation method for tube plate and tube bundle of floating head heat exchanger
CN109241642B (en) Method for judging instability bearing capacity of shell-and-tube heat exchanger
CN114818297B (en) Straight-section outer guide cylinder safety evaluation method, heat exchanger correction method and system
US5339868A (en) Bent pipe having sectional form of high strength
Schneider Flat face flanges with metal-to-metal contact beyond the bolt circle
CN110360389A (en) A kind of auxetic composite material conduit and transfer pipeline
Cao et al. Elastic analysis of a circular flange joint subjected to axial force
US7334609B2 (en) Flexible tubular device
US6896290B2 (en) Steering gear shaft for a steering column of a motor vehicle
CN112561147A (en) Thin-wall steel pipe explosion pressure prediction method
CN209416123U (en) A kind of high parameter spiral heat exchanger
EP3339599B1 (en) Bellows member
US20030173765A1 (en) Steering gear shaft for a steering column of a motor vehicle
CN116244849B (en) Optimal design method and system for incomplete pipe-distribution floating head heat exchanger
EP2013559B1 (en) Seal for tubular heat exchanger
US4434840A (en) Expansion joint for reactor or heat exchanger
CN109357561A (en) A kind of high parameter spiral heat exchanger
JPH0318440A (en) Can body structure, can body forming method and its device for electric hot water boiler
RU2502577C2 (en) Method of fixing heat exchange tubes in tube plates
EP0296251B1 (en) Bent pipe having high-strength cross-section
JPS6039915B2 (en) Meandering piping structure with double pipes

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
GR01 Patent grant
GR01 Patent grant