Design method for high-energy additional fluid discharge-in structure of ship condenser

Abstract

The invention discloses a ship condenser high-energy additional fluid discharge structure design method, and relates to the field of energy power system surface type condenser high-energy fluid discharge. The problem that input high parameters (temperature, pressure and the like) cannot be compatible with an application scene in an actual small space due to the fact that an existing condenser structure design method only considers energy reduction level and does not consider optimization of structure parameters is solved. The fluid type is determined according to input fluid thermal parameters and condenser saturation parameters; determining the fluid energy level according to the inner diameter of the water / steam inlet and the fluid thermal parameters; the water / steam inlet position of the condenser body is judged according to the fluid deoxidization state or the fluid energy level; determining the type and parameters of the selected diffusion element according to the fluid energy level; evaluating the service life of the diffusion element, judging whether the service life of the diffusion element meets the service life requirement or not, and if so, ending; if not, the curvature and the thickness of the diffusion element are adjusted so that the diffusion element can meet the service life requirement. The method is mainly used for structural design of the condenser.

Description

Technical Field

[0001] The invention relates to the field of high-energy fluid discharge of surface condensers in energy power systems. Background Art

[0002] As one of the most important components of the energy and power system, the cold end system plays an important role in maintaining the back pressure of the turbine and ensuring the efficient operation of the energy and power cycle system. At the same time, as a cold source, it also bears the functions of various drainage, exhaust steam and other discharges and condensation. However, if there are design problems such as improper steam (water) inlet position during the design of the condenser, it is very likely to reduce the cooling effect, and even cause impact damage to the condenser and the heat exchange tube bundle inside the condenser, thereby threatening the safety and efficiency of the condenser operation. Therefore, it is necessary to design and verify the condenser according to specific standards.

[0003] Since there are many types of working fluids entering the condenser, including cold water, saturated / superheated water, flash mixture and saturated / superheated steam, and the parameters such as temperature, pressure and flow rate of different working fluids are also quite different, it is required to write a separate program for each type of working fluid for design and verification. In addition, it is also necessary to write a program for judging the working fluid type in order to carry out various types of designs.

[0004] In order to solve the problems that may arise in surface condensers, such as inappropriate steam (water) inlet design, neglect of the mixed entry of steam and water, improper steam (water) inlet position and improper steam (water) inlet operation, requirements are put forward for the steam (water) inlet position, diffusion device selection, water velocity at the holes in the small-hole header and safety distance in the design procedure. Furthermore, it is necessary to accurately design parameters such as the number of holes, hole diameter, hole spacing and row spacing to avoid possible operational safety problems.

[0005] However, the existing condenser structure design method only considers energy level reduction and does not consider the optimization of structural parameters, resulting in incompatibility between input high parameters (temperature, pressure, etc.) and actual application scenarios in small spaces. Therefore, the above problems need to be solved urgently. Summary of the invention

[0006] The purpose of the present invention is to solve the problem that the existing condenser structure design method only considers the energy level reduction and does not consider the optimization of structural parameters, resulting in the incompatibility of input high parameters (temperature, pressure, etc.) with the actual application scenarios in a small space; the present invention provides a high-energy additional fluid discharge structure design method for a ship condenser.

[0007] A method for designing a high-energy additional fluid discharge structure for a ship condenser, the method comprising the following steps:

[0008] S1. Determine the fluid type according to the input fluid thermodynamic parameters and condenser saturation parameters;

[0009] S2. Determine the fluid energy level under the corresponding fluid type according to the inner diameter of the water / steam inlet and the fluid thermal parameters;

[0010] S3. Determine the water inlet / steam port position of the condenser body according to the fluid deoxygenation state or fluid energy level;

[0011] S4. Determine the type of diffusion element selected according to the fluid energy level, and determine the parameters of the selected diffusion element;

[0012] S5. Given the initial curvature and thickness of the diffusion element, the life of the diffusion element is evaluated to determine whether the life of the diffusion element meets the service life requirements. If the result is yes, the design is completed; if the result is no, the curvature and thickness of the diffusion element are adjusted to meet the service life requirements and the design is completed.

[0013] Preferably, S1, determining the fluid type according to the input fluid thermodynamic parameters and the condenser saturation parameters is implemented as follows:

[0014] Fluid thermodynamic parameters include fluid flow rate, fluid pressure, fluid temperature and fluid specific enthalpy;

[0015] The condenser saturation parameters include condenser saturation pressure, saturation temperature at condenser pressure, saturation water specific enthalpy and saturation steam specific enthalpy;

[0016] When the fluid temperature is ≤ the saturation temperature under the condenser pressure, the fluid type is determined to be cold water; when the fluid temperature is greater than the saturation temperature under the condenser pressure, the fluid pressure is greater than the condenser saturation pressure, and the fluid specific enthalpy is less than the saturated water specific enthalpy, the fluid type is determined to be superheated water;

[0017] When the fluid temperature > saturation temperature under condenser pressure, fluid pressure > condenser saturation pressure and fluid specific enthalpy = saturated water specific enthalpy are satisfied at the same time, the fluid type is determined to be saturated water;

[0018] When the fluid temperature > saturation temperature at condenser pressure, fluid pressure > condenser saturation pressure, and saturated water specific enthalpy < fluid specific enthalpy < saturated steam specific enthalpy are satisfied at the same time, the fluid type is determined to be a flash mixture;

[0019] When any two of the following three conditions are met: fluid temperature > saturation temperature at condenser pressure, fluid pressure > condenser saturation pressure, and fluid specific enthalpy > saturated steam specific enthalpy, the fluid type is determined to be superheated steam;

[0020] When any two of the following three conditions are met: fluid temperature = saturation temperature at condenser pressure, fluid pressure = condenser saturation pressure, and fluid specific enthalpy = saturated steam specific enthalpy, the fluid type is determined to be saturated steam.

[0021] Preferably, S2, determining the fluid energy level of the corresponding fluid type according to the inner diameter of the water / steam inlet and the fluid thermal parameters, comprises:

[0022] Fluid thermodynamic parameters include fluid flow rate, fluid pressure, fluid temperature and fluid specific enthalpy;

[0023] When the fluid type is cold water, the flow velocity in the pipe is calculated according to the inner diameter of the water / steam inlet and the fluid flow rate to determine whether the flow velocity in the pipe ≤ the maximum allowable flow velocity is satisfied. If the result is yes, the fluid energy level is determined to be a low energy level, otherwise, the fluid energy level is determined to be a high energy level;

[0024] When the fluid type is saturated water or superheated water, when the fluid temperature - the saturation temperature under the condenser pressure is ≤11.1℃, the fluid energy level is low; when 11.1℃<the saturation temperature under the fluid temperature - the condenser pressure is ≤55.6℃, the fluid energy level is medium; when the fluid temperature - the saturation temperature under the condenser pressure is >55.6℃, the fluid energy level is high;

[0025] When the fluid type is a flash mixture, calculate the flash volume G of the flash mixture. When the flash volume G ≤ 5% and the fluid flow rate < 9.072t / h, the fluid energy level is a low energy level; when the flash volume G > 5% and the flow rate in the pipe ≤ 47V 0.5 When the fluid energy level is medium, the flash volume G>5%, and the flow rate in the tube>47V 0.5 When , the fluid energy level is the high energy level, and V is the specific volume of the flash mixture;

[0026] When the fluid type is saturated steam or superheated steam: when the fluid pressure is less than 0.03447MPa or the fluid flow rate is less than 0.4572t / h, the fluid energy level is a low energy level; when 0.03447MPa≤fluid pressure≤1.7237MPa, and 0.4572t / h≤fluid flow rate≤9.144t / h, the fluid energy level is a medium energy level; when the fluid pressure is greater than 1.7237MPa or the fluid specific enthalpy is greater than 2884.678kJ / kg, and the fluid flow rate is greater than 9.144t / h, the fluid energy level is a high energy level.

[0027] Preferably,

[0028]

[0029] Among them, h 1 is the liquid enthalpy at the water / steam inlet pressure before flash, h 2 is the liquid enthalpy at condenser pressure, h fg is the latent heat of vaporization at the condenser pressure.

[0030] Preferably, the implementation of S3, determining the water inlet / steam port position of the condenser body according to the fluid deoxygenation state or fluid energy level, comprises:

[0031] S31, spatially dividing the condenser body from top to bottom into: throat area A, tube bundle upper area B, tube bundle area C, hot well upper area D and hot well area E;

[0032] S32, when the fluid type is cold water, when the fluid deoxygenation state is deoxygenated, the water inlet / steam port position is set in the upper area D of the hot well or the hot well area E; when the fluid deoxygenation state is not deoxygenated, the water inlet / steam port position is set in the upper area B of the tube bundle or the tube bundle area C;

[0033] When the fluid type is saturated water or superheated water, when the fluid deoxygenation state is deoxygenated, the water inlet / steam port position is set in the upper area B of the tube bundle, the tube bundle area C or the upper area D of the hot well; when the fluid deoxygenation state is not deoxygenated, the water inlet / steam port position is set in the upper area B of the tube bundle or the tube bundle area C;

[0034] When the fluid type is a flash mixture, when the fluid deoxygenation state is deoxygenated, the water / steam inlet position is set in the upper area B of the tube bundle, the tube bundle area C or the upper area D of the hot well; when the fluid deoxygenation state is not deoxygenated, the water / steam inlet position is set in the upper area B of the tube bundle or the tube bundle area C;

[0035] When the fluid type is saturated steam or superheated steam, when the fluid energy level is medium or low, the water inlet / steam port is set in the throat area A; when the fluid energy level is high, the water inlet / steam port is set in the upper area D of the hot well, and it is necessary to ensure that the steam diffuses to the entire condenser.

[0036] Preferably, S4, determining the type of diffusion element selected according to the fluid energy level, and determining the parameters of the diffusion element selected is implemented as follows:

[0037] When the fluid type is cold water, the diffusion element type is a guide baffle when the fluid energy level is medium or low, and the diffusion element type is a porous distribution header when the fluid energy level is high. The number of holes n and the hole spacing S of the porous distribution header are calculated. 0 , the implementation method of row spacing Sr and safety distance L:

[0038]

[0039] L = 50d;

[0040] S 0 =4d;

[0041] S r =3d;

[0042] Among them, Q is the flow rate, W 0 is the flow capacity of the hole, d is the pore diameter;

[0043] When the fluid type is saturated water, superheated water or flash mixture, the diffusion element type is a guide baffle when the fluid energy level is low, and the diffusion element type is a porous distribution header when the fluid energy level is medium or high. The number of holes n and the hole spacing S of the porous distribution header are calculated. 0 , the implementation method of row spacing Sr and safety distance L:

[0044]

[0045] L = 60d;

[0046]

[0047] Among them, Q is the flow rate, W 0 is the flow capacity of the hole, d is the hole diameter, G is the flash volume, and D is the inner diameter of the header;

[0048] When the fluid type is saturated steam or superheated steam, the diffusion element type is a guide baffle when the fluid energy level is medium or low, and the diffusion element type is a porous distribution header when the fluid energy level is high, and the number of holes n and the hole spacing S of the porous distribution header are calculated. 0 , the implementation method of row spacing Sr and safety distance L:

[0049]

[0050] S r =2d;

[0051] Among them, Q is the flow rate, W 0 is the flow capacity of the hole, d is the pore diameter, M j is the jet Mach number, V O V is the specific volume of steam at the water / steam inlet; C is the specific volume of steam at condenser pressure.

[0052] Preferably, in S5, a finite element model is established according to the condenser body structure, and the type and parameters of the selected diffusion element, and the life of the diffusion element is evaluated in the following manner:

[0053] S51. A finite element model is established based on the condenser body structure and the type and parameters of the selected diffusion element. When the fluid impacts the diffusion element in the finite element model, the damage degree D is calculated under the condition of setting the initial value of the erosion time t′. c ;

[0054] S52, according to D c , determine the fatigue limit σ' of the diffusion element after erosion damage f ;

[0055] S53, according to σ' f, estimate the life T of the diffusion element, and determine whether t′=T. If yes, the life T of the diffusion element is output as the result. Otherwise, adjust the value of the erosion time t′ so that t′=T, and then output the life T of the diffusion element at this time as the result.

[0056] Preferably, in S51,

[0057]

[0058] Where δ is the wall thickness of the diffusion element, e rc is the erosion rate, u is the relative velocity between the fluid and the wall, a is the erosion angle, and the erosion angle a=0° in the forward erosion, ε c is the shear coefficient.

[0059] Preferably, in S52, σ' f =σ f D c ; Among them, σ f is the fatigue limit of smooth diffusion element.

[0060] Preferably, S53, according to σ' f , the implementation method for determining the diffusion element life T is:

[0061] (σ-σ' f ) m NT = C;

[0062] Where σ is the maximum stress on the diffusion element, N is the number of stress cycles in one day, and m and C are the first and second constants of the material, respectively.

[0063] The beneficial effects brought by the present invention are:

[0064] The present invention provides a method for designing a high-energy additional fluid discharge structure for a ship condenser. The present invention first determines the fluid type by inputting parameters, and designs each fluid type separately, with different parameter design schemes, so that the scheme is more comprehensive and more practical, so that its input high parameters (temperature, pressure, etc.) are suitable for actual small spaces; in addition, the present invention first determines the type of diffusion element, and optimizes the structure of the diffusion element through life assessment, thereby improving the safety of the design scheme to ensure the normal operation of the condenser. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] Figure 1 It is a schematic diagram of the overall flow of the design method of the high-energy additional fluid discharge structure of the ship condenser according to the present invention;

[0066] Figure 2 It is a schematic diagram of the condenser area division;

[0067] Figure 3It is a schematic diagram of the fluid spraying to the tube bundle through the guide baffle and the porous distribution header;

[0068] Figure 4 This is a simplified structural diagram of the multi-hole distribution manifold. DETAILED DESCRIPTION

[0069] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0070] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0071] See also Figure 1 This embodiment is described. The method for designing a high-energy additional fluid discharge structure for a ship condenser described in this embodiment comprises the following steps:

[0072] S1. Determine the fluid type according to the input fluid thermodynamic parameters and condenser saturation parameters;

[0073] S2. Determine the fluid energy level under the corresponding fluid type according to the inner diameter of the water / steam inlet and the fluid thermal parameters;

[0074] S3. Determine the water inlet / steam port position of the condenser body according to the fluid deoxygenation state or fluid energy level;

[0075] S4. Determine the type of diffusion element selected according to the fluid energy level, and determine the parameters of the selected diffusion element;

[0076] S5. Given the initial curvature and thickness of the diffusion element, the life of the diffusion element is evaluated to determine whether the life of the diffusion element meets the service life requirements. If the result is yes, the design is completed; if the result is no, the curvature and thickness of the diffusion element are adjusted to meet the service life requirements and the design is completed.

[0077] The present invention first determines the fluid type by inputting parameters, and designs each fluid type separately, with different parameter design schemes, making the scheme more comprehensive and more practical, so that its input high parameters (temperature, pressure, etc.) are suitable for actual small spaces; in addition, the present invention first determines the type of diffusion element, and optimizes the structure of the diffusion element through life assessment, thereby improving the safety of the design scheme to ensure the normal operation of the condenser.

[0078] Further, S1, according to the input fluid thermodynamic parameters and the condenser saturation parameters, the implementation method of determining the fluid type is:

[0079] Fluid thermodynamic parameters include fluid flow rate, fluid pressure, fluid temperature and fluid specific enthalpy;

[0080] The condenser saturation parameters include condenser saturation pressure, saturation temperature at condenser pressure, saturation water specific enthalpy and saturation steam specific enthalpy;

[0081] When the fluid temperature is ≤ the saturation temperature under the condenser pressure, the fluid type is determined to be cold water; when the fluid temperature is greater than the saturation temperature under the condenser pressure, the fluid pressure is greater than the condenser saturation pressure, and the fluid specific enthalpy is less than the saturated water specific enthalpy, the fluid type is determined to be superheated water;

[0082] When the fluid temperature > saturation temperature under condenser pressure, fluid pressure > condenser saturation pressure and fluid specific enthalpy = saturated water specific enthalpy are satisfied at the same time, the fluid type is determined to be saturated water;

[0083] When the fluid temperature > saturation temperature at condenser pressure, fluid pressure > condenser saturation pressure, and saturated water specific enthalpy < fluid specific enthalpy < saturated steam specific enthalpy are satisfied at the same time, the fluid type is determined to be a flash mixture;

[0084] When any two of the following three conditions are met: fluid temperature > saturation temperature at condenser pressure, fluid pressure > condenser saturation pressure, and fluid specific enthalpy > saturated steam specific enthalpy, the fluid type is determined to be superheated steam;

[0085] When any two of the following three conditions are met: fluid temperature = saturation temperature at condenser pressure, fluid pressure = condenser saturation pressure, and fluid specific enthalpy = saturated steam specific enthalpy, the fluid type is determined to be saturated steam.

[0086] In this embodiment, a variety of judgment conditions are given to determine the type of fluid. The advantage of this design is that the state of the fluid after being discharged into the condenser can be quickly determined based on the fluid thermal parameters.

[0087] Further, S2, according to the inner diameter of the water / steam inlet and the fluid thermal parameters, the implementation method of determining the fluid energy level under the corresponding fluid type includes:

[0088] Fluid thermodynamic parameters include fluid flow rate, fluid pressure, fluid temperature and fluid specific enthalpy;

[0089] When the fluid type is cold water, the flow velocity in the pipe is calculated according to the inner diameter of the water / steam inlet and the fluid flow rate to determine whether the flow velocity in the pipe ≤ the maximum allowable flow velocity is satisfied. If the result is yes, the fluid energy level is determined to be a low energy level, otherwise, the fluid energy level is determined to be a high energy level;

[0090] When the fluid type is saturated water or superheated water, when the fluid temperature - the saturation temperature under the condenser pressure is ≤11.1℃, the fluid energy level is low; when 11.1℃<the saturation temperature under the fluid temperature - the condenser pressure is ≤55.6℃, the fluid energy level is medium; when the fluid temperature - the saturation temperature under the condenser pressure is >55.6℃, the fluid energy level is high;

[0091] When the fluid type is a flash mixture, calculate the flash volume G of the flash mixture. When the flash volume G ≤ 5% and the fluid flow rate < 9.072t / h, the fluid energy level is a low energy level; when the flash volume G > 5% and the flow rate in the pipe ≤ 47V 0.5 When the fluid energy level is medium, the flash volume G>5%, and the flow rate in the tube>47V 0.5 When , the fluid energy level is the high energy level, V is the specific volume of the flash mixture; specifically,

[0092]

[0093] Among them, h 1 is the liquid enthalpy at the water / steam inlet pressure before flash, h 2 is the liquid enthalpy at condenser pressure, h fg is the latent heat of vaporization at the condenser pressure;

[0094] When the fluid type is saturated steam or superheated steam: when the fluid pressure is less than 0.03447MPa or the fluid flow rate is less than 0.4572t / h, the fluid energy level is a low energy level; when 0.03447MPa≤fluid pressure≤1.7237MPa, and 0.4572t / h≤fluid flow rate≤9.144t / h, the fluid energy level is a medium energy level; when the fluid pressure is greater than 1.7237MPa or the fluid specific enthalpy is greater than 2884.678kJ / kg, and the fluid flow rate is greater than 9.144t / h, the fluid energy level is a high energy level.

[0095] In this embodiment, the corresponding energy level is determined specifically for different fluid types. The advantage of this determination method is that the corresponding energy level can be quickly evaluated according to the standard range of parameters of different types of fluids.

[0096] For further information, see Figure 2 S3. The implementation method of determining the water inlet / steam port position of the condenser body according to the fluid deoxygenation state or fluid energy level includes:

[0097] S31, spatially dividing the condenser body from top to bottom into: throat area A, tube bundle upper area B, tube bundle area C, hot well upper area D and hot well area E;

[0098] S32, when the fluid type is cold water, when the fluid deoxygenation state is deoxygenated, the water inlet / steam port position is set in the upper area D of the hot well or the hot well area E; when the fluid deoxygenation state is not deoxygenated, the water inlet / steam port position is set in the upper area B of the tube bundle or the tube bundle area C;

[0099] When the fluid type is saturated water or superheated water, when the fluid deoxygenation state is deoxygenated, the water inlet / steam port position is set in the upper area B of the tube bundle, the tube bundle area C or the upper area D of the hot well; when the fluid deoxygenation state is not deoxygenated, the water inlet / steam port position is set in the upper area B of the tube bundle or the tube bundle area C;

[0100] When the fluid type is a flash mixture, when the fluid deoxygenation state is deoxygenated, the water / steam inlet position is set in the upper area B of the tube bundle, the tube bundle area C or the upper area D of the hot well; when the fluid deoxygenation state is not deoxygenated, the water / steam inlet position is set in the upper area B of the tube bundle or the tube bundle area C;

[0101] When the fluid type is saturated steam or superheated steam, when the fluid energy level is medium or low, the water inlet / steam port is set in the throat area A; when the fluid energy level is high, the water inlet / steam port is set in the upper area D of the hot well, and it is necessary to ensure that the steam diffuses to the entire condenser.

[0102] In this preferred embodiment, a setting method for the water inlet / steam port position under different fluid types is given. The advantage of this setting method is that based on existing standard experience, a design method for the discharge position area of ​​different types of fluids into the condenser is formulated to make its design more reasonable.

[0103] For further information, see Figure 3 S4, the implementation method of determining the type of diffusion element selected according to the fluid energy level and determining the parameters of the diffusion element selected is:

[0104] When the fluid type is cold water, the diffusion element type is a guide baffle when the fluid energy level is medium or low, and the diffusion element type is a porous distribution header when the fluid energy level is high. The number of holes n and the hole spacing S of the porous distribution header are calculated. 0 , the implementation method of row spacing Sr and safety distance L:

[0105]

[0106] L = 50d;

[0107] S 0 =4d;

[0108] S r =3d;

[0109] Among them, Q is the flow rate, W 0is the flow capacity of the hole, d is the pore diameter;

[0110] When the fluid type is saturated water, superheated water or flash mixture, the diffusion element type is a guide baffle when the fluid energy level is low, and the diffusion element type is a porous distribution header when the fluid energy level is medium or high. The number of holes n and the hole spacing S of the porous distribution header are calculated. 0 , the implementation method of row spacing Sr and safety distance L:

[0111]

[0112] L = 60d;

[0113]

[0114] Among them, Q is the flow rate, W 0 is the flow capacity of the hole, d is the hole diameter, G is the flash volume, and D is the inner diameter of the header;

[0115] When the fluid type is saturated steam or superheated steam, the diffusion element type is a guide baffle when the fluid energy level is medium or low, and the diffusion element type is a porous distribution header when the fluid energy level is high, and the number of holes n and the hole spacing S of the porous distribution header are calculated. 0 , the implementation method of row spacing Sr and safety distance L:

[0116]

[0117] S r =2d;

[0118] Among them, Q is the flow rate, W 0 is the flow capacity of the hole, d is the pore diameter, M j is the jet Mach number, V o is the specific volume of steam at the water / steam inlet, V C is the specific volume of steam at condenser pressure.

[0119] In the preferred embodiment, the type of diffusion element selected and the parameters of the diffusion element are determined according to the energy level of the fluid, which has the advantage of achieving an optimized design of the diffusion element under different fluid forms.

[0120] Furthermore, in S5, a finite element model is established according to the condenser body structure and the type and parameters of the selected diffusion element, and the life of the diffusion element is evaluated in the following manner:

[0121] S51. A finite element model is established based on the condenser body structure and the type and parameters of the selected diffusion element. When the fluid impacts the diffusion element in the finite element model, the damage degree D is calculated under the condition of setting the initial value of the erosion time t′. c ; Specifically,

[0122]

[0123]

[0124] Where t′ is the erosion time in days, δ is the wall thickness of the diffusion element, and e rc is the erosion rate, u is the relative velocity between the fluid and the wall, a is the erosion angle, and the erosion angle a=0° in the forward erosion, ε c is the shear coefficient;

[0125] S52, according to D c , determine the fatigue limit σ' of the diffusion element after erosion damage f ; Specifically,

[0126] σ' f =σ f D c ;

[0127] Among them, σ f is the fatigue limit of the smooth diffusion element;

[0128] S53, according to σ' f , estimate the life T of the diffusion element, and determine whether t′=T. If yes, the life T of the diffusion element is output as the result. Otherwise, adjust the value of the erosion time t′ so that t′=T, and then output the life T of the diffusion element at this time as the result.

[0129] Specifically, according to σ' f , the implementation method for determining the diffusion element life T is:

[0130] (σ-σ' f ) m NT = C;

[0131] Where σ is the maximum stress on the diffusion element, N is the number of stress cycles in one day, and m and C are the first and second constants of the material, respectively.

[0132] In this preferred embodiment, the life of the diffusion element is evaluated by combining finite element analysis, and the life of the diffusion element under different fluid types is evaluated, thereby achieving structural optimization of the diffusion element.

[0133] The ship condenser high-energy additional fluid discharge structure design method described in the present invention can also be used in the verification field when it is applied specifically. Specifically, the design method of the present invention can be used to verify the effectiveness of the existing ship condenser structure design method, mainly to verify whether the water inlet / steam port position and the selected diffusion element type and parameters in the prior art ship condenser structure design method are reasonable.

[0134] Although the present invention is described herein with reference to specific embodiments, it should be understood that these embodiments are merely examples of the principles and applications of the present invention. It should therefore be understood that many modifications may be made to the exemplary embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims. It should be understood that the various dependent claims and features described herein may be combined in a manner different from that described in the original claims. It should also be understood that features described in conjunction with individual embodiments may be used in other described embodiments.

Claims

1. A design method for a high-energy additional fluid discharge structure for a ship condenser, characterized in that: The method comprises the following steps: S1. Determine the fluid type according to the input fluid thermodynamic parameters and condenser saturation parameters; S2. Determine the fluid energy level under the corresponding fluid type according to the inner diameter of the water / steam inlet and the fluid thermal parameters; S3. Determine the water inlet / steam port position of the condenser body according to the fluid deoxygenation state or fluid energy level; S4. Determine the type of diffusion element selected according to the fluid energy level, and determine the parameters of the selected diffusion element; S5. Under the initial given curvature and thickness of the diffusion element, a finite element model is established according to the condenser body structure, and the type and parameters of the selected diffusion element, and the life of the diffusion element is evaluated to determine whether the life of the diffusion element meets the service life requirements. If the result is yes, the design is completed; if the result is no, the curvature and thickness of the diffusion element are adjusted to meet the service life requirements and the design is completed.

2. The method for designing a high-energy additional fluid discharge structure for a ship condenser according to claim 1, characterized in that: S1. According to the input fluid thermodynamic parameters and condenser saturation parameters, the implementation method of determining the fluid type is: Fluid thermodynamic parameters include fluid flow rate, fluid pressure, fluid temperature and fluid specific enthalpy; The condenser saturation parameters include condenser saturation pressure, saturation temperature at condenser pressure, saturation water specific enthalpy and saturation steam specific enthalpy; When the fluid temperature is ≤ the saturation temperature under the condenser pressure, the fluid type is determined to be cold water; when the fluid temperature is greater than the saturation temperature under the condenser pressure, the fluid pressure is greater than the condenser saturation pressure, and the fluid specific enthalpy is less than the saturated water specific enthalpy, the fluid type is determined to be superheated water; When the fluid temperature > saturation temperature under condenser pressure, fluid pressure > condenser saturation pressure and fluid specific enthalpy = saturated water specific enthalpy are satisfied at the same time, the fluid type is determined to be saturated water; When the fluid temperature > saturation temperature at condenser pressure, fluid pressure > condenser saturation pressure, and saturated water specific enthalpy < fluid specific enthalpy < saturated steam specific enthalpy are satisfied at the same time, the fluid type is determined to be a flash mixture; When any two of the following three conditions are met: fluid temperature > saturation temperature at condenser pressure, fluid pressure > condenser saturation pressure, and fluid specific enthalpy > saturated steam specific enthalpy, the fluid type is determined to be superheated steam; When any two of the following three conditions are met: fluid temperature = saturation temperature at condenser pressure, fluid pressure = condenser saturation pressure, and fluid specific enthalpy = saturated steam specific enthalpy, the fluid type is determined to be saturated steam.

3. The method for designing a high-energy additional fluid discharge structure for a ship condenser according to claim 1, characterized in that: S2. The implementation methods of determining the fluid energy level under the corresponding fluid type according to the inner diameter of the water / steam inlet and the fluid thermal parameters include: Fluid thermodynamic parameters include fluid flow rate, fluid pressure, fluid temperature and fluid specific enthalpy; When the fluid type is cold water, the flow velocity in the pipe is calculated according to the inner diameter of the water / steam inlet and the fluid flow rate to determine whether the flow velocity in the pipe ≤ the maximum allowable flow velocity is satisfied. If the result is yes, the fluid energy level is determined to be a low energy level, otherwise, the fluid energy level is determined to be a high energy level; When the fluid type is saturated water or superheated water, when the fluid temperature - the saturation temperature under the condenser pressure is ≤11.1℃, the fluid energy level is low; when 11.1℃<the saturation temperature under the fluid temperature - the condenser pressure is ≤55.6℃, the fluid energy level is medium; when the fluid temperature - the saturation temperature under the condenser pressure is >55.6℃, the fluid energy level is high; When the fluid type is a flash mixture, calculate the flash volume G of the flash mixture. When the flash volume G ≤ 5% and the fluid flow rate < 9.072t / h, the fluid energy level is a low energy level; when the flash volume G > 5% and the flow rate in the pipe ≤ 47V 0.5 When the fluid energy level is medium, the flash volume G>5%, and the flow rate in the tube>47V 0.5 When , the fluid energy level is the high energy level, and V is the specific volume of the flash mixture; When the fluid type is saturated steam or superheated steam: when the fluid pressure is less than 0.03447MPa or the fluid flow rate is less than 0.4572t / h, the fluid energy level is a low energy level; when 0.03447MPa≤fluid pressure≤1.7237MPa, and 0.4572t / h≤fluid flow rate≤9.144t / h, the fluid energy level is a medium energy level; when the fluid pressure is greater than 1.7237MPa or the fluid specific enthalpy is greater than 2884.678kJ / kg, and the fluid flow rate is greater than 9.144t / h, the fluid energy level is a high energy level.

4. The method for designing a high-energy additional fluid discharge structure for a ship condenser according to claim 1, characterized in that: Where h1 is the liquid enthalpy at the water / steam inlet pressure before flash, h2 is the liquid enthalpy at the condenser pressure, and h fg is the latent heat of vaporization at the condenser pressure.

5. The method for designing a high-energy additional fluid discharge structure for a ship condenser according to claim 1, characterized in that: S3. The implementation method of determining the water inlet / steam port position of the condenser body according to the fluid deoxygenation state or fluid energy level includes: S31, spatially dividing the condenser body from top to bottom into: throat area A, tube bundle upper area B, tube bundle area C, hot well upper area D and hot well area E; S32, when the fluid type is cold water, when the fluid deoxygenation state is deoxygenated, the water inlet / steam port position is set in the upper area D of the hot well or the hot well area E; when the fluid deoxygenation state is not deoxygenated, the water inlet / steam port position is set in the upper area B of the tube bundle or the tube bundle area C; When the fluid type is saturated water or superheated water, when the fluid deoxygenation state is deoxygenated, the water inlet / steam port position is set in the upper area B of the tube bundle, the tube bundle area C or the upper area D of the hot well; when the fluid deoxygenation state is not deoxygenated, the water inlet / steam port position is set in the upper area B of the tube bundle or the tube bundle area C; When the fluid type is a flash mixture, when the fluid deoxygenation state is deoxygenated, the water / steam inlet position is set in the upper area B of the tube bundle, the tube bundle area C or the upper area D of the hot well; when the fluid deoxygenation state is not deoxygenated, the water / steam inlet position is set in the upper area B of the tube bundle or the tube bundle area C; When the fluid type is saturated steam or superheated steam, when the fluid energy level is medium or low, the water inlet / steam port is set in the throat area A; when the fluid energy level is high, the water inlet / steam port is set in the upper area D of the hot well, and it is necessary to ensure that the steam diffuses to the entire condenser.

6. The method for designing a high-energy additional fluid discharge structure for a ship condenser according to claim 1, characterized in that: S4. The implementation method of determining the type of diffusion element selected according to the fluid energy level and determining the parameters of the selected diffusion element is as follows: When the fluid type is cold water, the diffusion element type is a guide baffle when the fluid energy level is medium or low, and the diffusion element type is a porous distribution header when the fluid energy level is high. The implementation method for obtaining the number of holes n, hole spacing S0, row spacing Sr and safety distance L of the porous distribution header is as follows: L = 50d; S0=4d; S r =3d; Among them, Q is the flow rate, W0 is the flow capacity of the hole, and d is the pore diameter; When the fluid type is saturated water, superheated water or flash mixture, the diffusion element type is a guide baffle when the fluid energy level is low, and the diffusion element type is a porous distribution header when the fluid energy level is medium or high. The implementation method of obtaining the number of holes n, hole spacing S0, row spacing Sr and safety distance L of the porous distribution header is as follows: L = 60d; Among them, Q is the flow rate, W0 is the flow capacity of the hole, d is the hole diameter, G is the flash volume, and D is the inner diameter of the header; When the fluid type is saturated steam or superheated steam, the diffusion element type is a guide baffle when the fluid energy level is medium or low, and the diffusion element type is a porous distribution header when the fluid energy level is high. The implementation method for obtaining the number of holes n, hole spacing S0, row spacing Sr and safety distance L of the porous distribution header is as follows: S r =2d; Where Q is the flow rate, W0 is the flow capacity of the hole, d is the pore diameter, M j is the jet Mach number, V O V is the specific volume of steam at the water / steam inlet; C is the specific volume of steam at condenser pressure.

7. The method for designing a high-energy additional fluid discharge structure for a ship condenser according to claim 1, characterized in that: In S5, the implementation method of evaluating the life of the diffusion element is: S51. A finite element model is established based on the condenser body structure and the type and parameters of the selected diffusion element. When the fluid impacts the diffusion element in the finite element model, the damage degree D is calculated under the condition of setting the initial value of the erosion time t′. c ; S52, according to D c , determine the fatigue limit σ' of the diffusion element after erosion damage f ; S53, according to σ' f , estimate the life T of the diffusion element, and determine whether t′=T. If yes, the life T of the diffusion element is output as the result. Otherwise, adjust the value of the erosion time t′ so that t′=T, and then output the life T of the diffusion element at this time as the result.

8. The method for designing a high-energy additional fluid discharge structure for a ship condenser according to claim 7, characterized in that: S51, Where δ is the wall thickness of the diffusion element, e rc is the erosion rate, u is the relative velocity between the fluid and the wall, a is the erosion angle, and the erosion angle a=0° in the forward erosion, ε c is the shear coefficient.

9. The method for designing a high-energy additional fluid discharge structure for a ship condenser according to claim 7, characterized in that: In S52, σ' f =σ f D c ; Among them, σ f is the fatigue limit of smooth diffusion element.

10. The method for designing a high-energy additional fluid discharge structure for a ship condenser according to claim 7, characterized in that: S53, according to σ' f , the implementation method for determining the diffusion element life T is: (s-s' f ) m ·NT=C; Where σ is the maximum stress on the diffusion element, N is the number of stress cycles in one day, and m and C are the first and second constants of the material, respectively.

Images