Critical power and inlet temperature correction method and system for fuel assembly CHF test

Abstract

The present invention provides a method and system for correcting the critical power and inlet temperature of a CHF test of a fuel assembly, comprising: obtaining test data in an original data table; confirming the qualitative temperature of a nickel rod based on the test data; obtaining the resistivity ρ based on the qualitative temperature; obtaining the resistance value R based on the resistivity ρ; obtaining the test critical power P based on the test data and the resistance value R jg , make corrections; based on the test data and test power, the enthalpy rise Δh of the nickel rod is obtained; based on the test data, the enthalpy value h of the nickel rod is calculated in ; According to the enthalpy rise Δh and enthalpy value h in , calculate the inlet enthalpy value h of the heating section of the nickel rod jg ; Based on the inlet enthalpy value h of the heating section of the nickel rod jg The inlet temperature T of the heating section of the nickel rod is calculated based on the experimental data. jg The present invention obtains more accurate CHF test results and data analysis through inlet temperature correction and power correction to improve the reliability and comparability of the test.

Description

Technical Field

[0001] The present invention belongs to the technical field of temperature control, and specifically relates to a method and system for correcting the critical power and inlet temperature in a CHF test of a fuel assembly. Background Art

[0002] The CHF test is an important part of the research on fluid boiling heat transfer, and it is one of the key tests for evaluating the heat transfer performance of fluids and clarifying the fluid boiling mechanism. The CHF test plays an important role in fluid heat transfer research, engineering design, and safety assessment, and can provide experimental data on CHF phenomena, fluid boiling pool mechanisms, and heat transfer performance, providing strong support for theoretical research and engineering applications in related fields.

[0003] Specifically, the critical heat flux density, i.e., CHF, is a key focus in the thermal-hydraulic design and safety analysis of reactors. When CHF occurs on the surface of a fuel rod, heat transfer deteriorates rapidly, and the temperature of the cladding surface rises rapidly, directly threatening the integrity of the cladding. Therefore, accurately obtaining the CHF value of a fuel assembly is of great significance for core design. Currently, people often use small-scale rod bundle assemblies to conduct tests to obtain CHF data and develop CHF relationships, and predict the CHF of fuel assemblies through the relationships. Therefore, the accuracy of experimental data is crucial.

[0004] The significance of correcting the inlet temperature and power lies in obtaining more accurate experimental results and data analysis to improve the reliability and comparability of the tests.

[0005] Currently, the existing measurement methods obtain the power of the heating rod by directly measuring voltage and current, without considering the influence of the power ratio of the non-heating section of the heating rod. If this problem is not solved, it will lead to inaccurate calculation of the experimental critical power. Therefore, the existing power measurement methods need to be improved. The existing measurement methods can only obtain the inlet temperature of the pressure-bearing shell outside the body, without considering the temperature rise of the fluid caused by the power of the non-heating section at the lower part of the heating rod. Therefore, correction is required to obtain the true inlet temperature at the starting point of the heating section of the heating rod.

[0006] Correcting the inlet temperature and power eliminates the interference of external factors on the test results, makes the data under different test conditions more comparable, thus better understanding and interpreting the test results, improving the accuracy of the data, and improving work efficiency. Summary of the Invention

[0007] Aiming at the defects in the prior art, the purpose of the present invention is to provide a method and system for correcting the critical power and inlet temperature in a CHF test of a fuel assembly.

[0008] According to a method for correcting the critical power and inlet temperature in a CHF test of a fuel assembly provided by the present invention, it includes:

[0009] Step S1: Obtain the test data in the original data table;

[0010] Step S2: Based on the test data, confirm the qualitative temperature of the nickel rod;

[0011] Step S3: Based on the qualitative temperature, obtain the resistivity ρ;

[0012] Step S4: Based on the resistivity ρ, obtain the resistance value R;

[0013] Step S5: Based on the test data and the resistance value R, obtain the test critical power P jg , and perform correction;

[0014] Step S6: Based on the test data and the test power, obtain the enthalpy rise Δh of the nickel rod; based on the test data, calculate the enthalpy value h of the nickel rod in ;

[0015] Step S7: According to the enthalpy rise Δh and the enthalpy value h obtained in Step S6 in , calculate the inlet enthalpy value h of the heating section of the nickel rod jg ;

[0016] Step S8: Based on the inlet enthalpy value h of the heating section of the nickel rod jg and the test data, calculate the inlet temperature T of the heating section of the nickel rod jg , and complete the correction.

[0017] Preferably, the nickel rod is divided into four parts from top to bottom, namely: the upper nickel section, the heating section, the lower nickel tube section and the lower copper tube section;

[0018] In the said Step S1:

[0019] The said test data includes: the inlet temperature T in , the inlet pressure P in , the outlet pressure P out , the inlet flow rate Q m , and the test CHF power P as the test power;

[0020] In the said Step S2:

[0021] The said qualitative temperature includes: T t , T nx , T jr and T ns , and the mathematical expression is:

[0022] T t is the normal temperature

[0023] T nx = T in

[0024] Tns = f(P out )

[0025] T jr = (T nx + T ns ) / 2

[0026] Wherein, T t is the qualitative temperature of the lower copper tube section, T nx is the qualitative temperature of the lower nickel tube section, T ns is the qualitative temperature of the upper nickel rod, f represents the fluid physical property query function, and T jr is the qualitative temperature of the heating section.

[0027] Preferably, in the step S3:

[0028] The resistivity ρ includes: ρ ns , ρ jg , ρ nx , ρ t , and the mathematical expression is:

[0029] ρ = f(T)

[0030] ρ ns = f(T ns )

[0031] ρ jg = f(T jr )

[0032] ρ nx = f(T nx )

[0033] ρ t = f(T t )

[0034] Wherein, T is the temperature, ρ ns is the resistivity of the upper nickel rod, ρ jg is the resistivity of the heating section, ρ nx is the resistivity of the lower nickel tube section, ρ t is the resistivity of the lower copper tube section;

[0035] In the step S4:

[0036] According to the resistivity, the resistance value R is obtained; the resistance value R includes: R ns , R jg , R nx , R t ;

[0037] R = ρ × l / s

[0038] R ns = ρns × l / s

[0039] R jg = ρ jg × l / s

[0040] R nx = ρ nx × l / s

[0041] R t = ρ t × l / s

[0042] Wherein, l is the axial length of each nickel tube section, and s is the cross-sectional area of each nickel tube section;

[0043] Wherein, R ns is the resistance of the upper nickel rod, R jg is the resistance of the heating section, R nx is the resistance of the lower nickel tube section, R t is the resistance of the lower copper tube section.

[0044] Preferably, in the step S5: according to the test CHF power P and the resistance values of each section of the nickel rod, the corrected power, that is, the test critical power P jg and the power P nx of the lower nickel section;

[0045] The test critical power P jg , the mathematical expression is:

[0046] P jg = P × R jg / (R ns + R jg + R nx + R t )

[0047] The power P nx of the lower nickel section, the mathematical expression is:

[0048] P nx = P × R nx / (R ns + R jg + R nx + R t ).

[0049] Preferably, in the step S6: according to the inlet flow rate Q m and the power P nx of the lower nickel section, the enthalpy rise Δh of the lower nickel tube section is obtained; according to the inlet temperature T in and the inlet pressure P in , the enthalpy value h in of the lower nickel tube is calculated;

[0050] The enthalpy rise Δh of the lower nickel tube section is expressed by the mathematical formula:

[0051] Δh = P nx / Q m

[0052] The enthalpy value h at the inlet of the lower nickel tube in , is expressed by the mathematical formula:

[0053] h in = f(P in , T in )

[0054] In the step S7: According to the enthalpy rise Δh of the lower nickel tube section and the enthalpy value h at the inlet of the lower nickel tube obtained in the step S6 in , the enthalpy value h at the inlet of the heating section is calculated jg ;

[0055] The enthalpy value h at the inlet of the heating section jg , is expressed by the mathematical formula:

[0056] h jg = Δh + h in

[0057] In the step S8: Based on the enthalpy value h at the inlet of the heating section jg and the inlet pressure P in , the inlet temperature T of the heating section is calculated jg ;

[0058] The inlet temperature T of the heating section jg , is expressed by the mathematical formula:

[0059] T jg = f(P in , h jg ).

[0060] A critical power and inlet temperature correction system for CHF tests of a fuel assembly according to the present invention includes:

[0061] Module M1: Obtain test data from the original data table;

[0062] Module M2: Confirm the qualitative temperature of the nickel rod based on the test data;

[0063] Module M3: Obtain the resistivity ρ based on the qualitative temperature;

[0064] Module M4: Obtain the resistance value R based on the resistivity ρ;

[0065] Module M5: Obtain the test critical power P based on the test data and the resistance value Rjg , make corrections;

[0066] Module M6: Based on the test data and test power, obtain the enthalpy rise Δh of the nickel rod; based on the test data, calculate the enthalpy value h of the nickel rod in ;

[0067] Module M7: According to the enthalpy rise Δh and enthalpy value h obtained by Module M6 in , calculate the inlet enthalpy value h of the heating section of the nickel rod jg ;

[0068] Module M8: Based on the inlet enthalpy value h of the heating section of the nickel rod jg and the test data, calculate the inlet temperature T of the heating section of the nickel rod jg , and complete the correction.

[0069] Preferably, the nickel rod is divided into four parts from top to bottom, namely: the upper nickel section, the heating section, the lower nickel tube section, and the lower copper tube section;

[0070] In Module M1:

[0071] The test data includes: the inlet temperature T in , the inlet pressure P in , the outlet pressure P out , the inlet flow rate Q m , and the test CHF power P as the test power;

[0072] In Module M2:

[0073] The qualitative temperature includes: T t , T nx , T jr and T ns , and the mathematical expression is:

[0074] T t is the normal temperature

[0075] T nx = T in

[0076] T ns = f(P out )

[0077] T jr =(T nx + T ns ) / 2

[0078] where, T t is the qualitative temperature of the lower copper tube section, T nx is the qualitative temperature of the lower nickel tube section, T nsis the characteristic temperature of the upper nickel rod, f represents the fluid physical property query function, and T jr is the characteristic temperature of the heating section.

[0079] Preferably, in the module M3:

[0080] The resistivity ρ includes: ρ ns 、ρ jg 、ρ nx 、ρ t , and the mathematical expression is:

[0081] ρ = f(T)

[0082] ρ ns = f(T ns )

[0083] ρ jg = f(T jr )

[0084] ρ nx = f(T nx )

[0085] ρ t = f(T t )

[0086] where T is the temperature, ρ ns is the resistivity of the upper nickel rod, ρ jg is the resistivity of the heating section, ρ nx is the resistivity of the lower nickel tube section, ρ t is the resistivity of the lower copper tube section;

[0087] In the module M4:

[0088] According to the resistivity, the resistance value R is obtained; the resistance value R includes: R ns 、R jg 、R nx 、R t ;

[0089] R = ρ × l / s

[0090] R ns = ρ ns × l / s

[0091] R jg = ρ jg × l / s

[0092] R nx = ρ nx × l / s

[0093] R t = ρ t × l / s

[0094] where l is the axial length of each nickel tube section, and s is the cross-sectional area of each nickel tube section;

[0095] where R ns is the resistance of the upper nickel rod, R jg is the resistance of the heating section, R nx is the resistance of the lower nickel tube section, R t is the resistance of the lower copper tube section.

[0096] Preferably, in the module M5: According to the test CHF power P and the resistance values of each section of the nickel rod, the corrected power, that is, the test critical power P jg and the power P nx of the lower nickel section;

[0097] The test critical power P jg , the mathematical expression is:

[0098] P jg = P × R jg / (R ns + R jg + R nx + R t )

[0099] The power P nx of the lower nickel section, the mathematical expression is:

[0100] P nx = P × R nx / (R ns + R jg + R nx + R t ).

[0101] Preferably, in the module M6: According to the inlet flow rate Q m and the power P nx of the lower nickel section, the enthalpy rise Δh of the lower nickel tube section is obtained; According to the inlet temperature T in and the inlet pressure P in , the enthalpy value h in of the lower nickel tube is calculated;

[0102] The enthalpy rise Δh of the lower nickel tube section, the mathematical expression is:

[0103] Δh = P nx / Q m

[0104] The enthalpy value h in at the inlet of the lower nickel tube, the mathematical expression is:

[0105] h in= f(P in , T in )

[0106] In the module M7: According to the enthalpy rise Δh of the lower nickel tube section and the enthalpy value h at the inlet of the lower nickel tube obtained in the module M6 in , the enthalpy value h at the inlet of the heating section is calculated jg ;

[0107] The enthalpy value h at the inlet of the heating section jg , and the mathematical expression is:

[0108] h jg = Δh + h in

[0109] In the module M8: Based on the enthalpy value h at the inlet of the heating section jg and the inlet pressure P in , the inlet temperature T of the heating section is calculated jg ;

[0110] The inlet temperature T of the heating section jg , and the mathematical expression is:

[0111] T jg = f(P in , h jg ).

[0112] Compared with the prior art, the present invention has the following beneficial effects:

[0113] 1. The present invention obtains the power ratio through the resistance ratio of the heating section of the nickel rods as the rod bundle, and then calculates the actual power of the heating section through the total power, realizing power correction;

[0114] 2. The present invention calculates the fluid enthalpy rise from the inlet of the pressure-bearing shell to the starting point of the heating section of the nickel rods, and obtains the corrected inlet temperature at the starting point of the heating section, realizing inlet temperature correction;

[0115] 3. The present invention obtains more accurate CHF test experimental results and data analysis through inlet temperature correction and power correction, so as to improve the reliability and comparability of the test. BRIEF DESCRIPTION OF THE DRAWINGS

[0116] By reading the following detailed description of the non-limiting embodiments with reference to the accompanying drawings, other features, objects and advantages of the present invention will become more apparent:

[0117] Figure 1 is the process schematic diagram provided by the present invention;

[0118] Figure 2 is the sample rod schematic diagram provided by the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0119] The present invention will be described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but do not limit the present invention in any form. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several changes and improvements can still be made. These all fall within the protection scope of the present invention.

[0120] This solution mainly overcomes the technical problems of inaccurate critical power in existing experiments and difficult measurement of the inlet temperature at the starting point of the heating section of the heating rod. Specifically, to achieve power correction, the power ratio of the heating section of the nickel rod as the rod bundle is obtained through the resistance ratio of the heating section, and then the actual power of the heating section is calculated from the total power; to achieve inlet temperature correction, the fluid enthalpy rise from the inlet of the pressure-bearing shell to the starting point of the heating section of the nickel rod as the heating rod is calculated to obtain the corrected inlet temperature at the starting point of the heating section; the above two are the key points of the present invention.

[0121] According to a method for correcting the critical power and inlet temperature in the CHF test of a fuel assembly provided by the present invention, its flow is as Figure 1 shown, and the schematic diagram of the sample rod structure is as Figure 2 shown;

[0122] A sample rod, that is, a nickel rod, is divided into four regions from top to bottom, which are: the upper nickel section, the heating section, the lower nickel tube section, and the lower copper tube section. The position of the pressure-bearing shell is the position of the lower nickel tube section.

[0123] The present invention provides a method for correcting the critical power and inlet temperature in the CHF test of a fuel assembly, including:

[0124] Step 1: Obtain the test data in the original data table;

[0125] Step 2: Confirm the qualitative temperature of each section;

[0126] Step 3: Obtain the resistivity of each corresponding section according to the qualitative temperature of each section;

[0127] Step 4: Obtain the resistance value of each section according to the resistivity of each section obtained;

[0128] Step 5: Obtain the corrected power P jg and the power P nx of the lower nickel section according to the test power P and the resistance values of each section;

[0129] Step 6: Obtain the enthalpy rise Δh of the lower nickel tube section according to the flow rate Q m obtained in Step 1 nx and the power P

[0130] Step 7: Calculate the enthalpy value h of the lower nickel tube based on the inlet temperature T obtained in Step 1 in and the inlet pressure P in ; in ;

[0131] Step 8: Calculate the inlet enthalpy value h of the heating section based on the enthalpy rise Δh of the lower nickel tube section obtained in Step 6 and the enthalpy value h of the inlet of the lower nickel tube obtained in Step 7 in ; jg ;

[0132] Step 9: Calculate the inlet temperature T of the heating section based on the inlet enthalpy value h of the heating section jg and the inlet pressure P in ; jg ;

[0133] That is to say, Step S1: Obtain the test data in the original data table;

[0134] Step S2: Confirm the qualitative temperature of the nickel rod based on the test data;

[0135] Step S3: Obtain the resistivity ρ based on the qualitative temperature;

[0136] Step S4: Obtain the resistance value R based on the resistivity ρ;

[0137] Step S5: Obtain the test critical power P based on the test data and the resistance value R jg , and make corrections;

[0138] Step S6: Obtain the enthalpy rise Δh of the nickel rod based on the test data and the test power: Calculate the enthalpy value h of the nickel rod based on the test data in ;

[0139] Step S7: Calculate the inlet enthalpy value h of the heating section of the nickel rod based on the enthalpy rise Δh and the enthalpy value h obtained in Step S6 in ; jg ;

[0140] Step S8: Calculate the inlet temperature T of the heating section of the nickel rod based on the inlet enthalpy value h of the heating section of the nickel rod jg and the test data, and complete the correction. jg ;

[0141] The test data includes: inlet temperature T in , inlet pressure P in , outlet pressure P out , inlet flow rate Q m , and test CHF power P;

[0142] In the said Step S1:

[0143] The test data includes: inlet temperature T in , inlet pressure P in , outlet pressure P out , inlet flow rate Q m , and the test CHF power P as the test power;

[0144] In the step S2:

[0145] The qualitative temperature includes: T t , T nx , T jr and T ns , and the mathematical expression is:

[0146] T t is the normal temperature

[0147] T nx = T in

[0148] T ns = f(P out )

[0149] T jr = (T nx + T ns ) / 2

[0150] where, T t is the qualitative temperature of the lower copper tube section, T nx is the qualitative temperature of the lower nickel tube section, T ns is the qualitative temperature of the upper nickel rod, f represents the fluid property query function, and T jr is the qualitative temperature of the heating section.

[0151] Specifically, in the step S3:

[0152] The resistivity ρ includes: ρ ns , ρ jg , ρ nx , ρ t , and the mathematical expression is:

[0153] ρ = f(T)

[0154] ρ ns = f(T ns )

[0155] ρ jg = f(T jr )

[0156] ρ nx = f(T nx )

[0157] ρt = f(T t )

[0158] where T is the temperature, ρ ns is the resistivity of the upper nickel rod, ρ jg is the resistivity of the heating section, ρ nx is the resistivity of the lower nickel tube section, ρ t is the resistivity of the lower copper tube section;

[0159] In the step S4:

[0160] According to the resistivity, the resistance value R is obtained; the resistance value R includes: R ns , R jg , R nx , R t ;

[0161] R = ρ × l / s

[0162] R ns = ρ ns × l / s

[0163] R jg = ρ jg × l / s

[0164] R nx = ρ nx × l / s

[0165] R t = ρ t × l / s

[0166] where l is the axial length of each nickel tube section and s is the cross-sectional area of each nickel tube section;

[0167] where R ns is the resistance of the upper nickel rod, R jg is the resistance of the heating section, R nx is the resistance of the lower nickel tube section, R t is the resistance of the lower copper tube section.

[0168] Specifically, in the step S5: According to the test CHF power P and the resistance values of each section of the nickel rod, the corrected power, that is, the test critical power P jg and the power P of the lower nickel section nx ;

[0169] The test critical power P jg , the mathematical expression is:

[0170] P jg = P × R jg / (R ns + Rjg +R nx +R t )

[0171] The power P of the lower nickel section nx , the mathematical expression is:

[0172] P nx = P × R nx / (R ns +R jg +R nx +R t ).

[0173] Specifically, in the step S6: According to the flow rate Q m and the power P of the lower nickel section nx , the enthalpy rise Δh of the lower nickel pipe section is obtained; According to the inlet temperature T in and the inlet pressure P in , the enthalpy value h of the lower nickel pipe is calculated in ;

[0174] The enthalpy rise Δh of the lower nickel pipe section, the mathematical expression is:

[0175] Δh = P nx / Q m

[0176] The enthalpy value h at the inlet of the lower nickel pipe in , the mathematical expression is:

[0177] h in = f(P in , T in )

[0178] In the step S7: According to the enthalpy rise Δh of the lower nickel pipe section and the enthalpy value h at the inlet of the lower nickel pipe obtained in the step S6 in , the enthalpy value h at the inlet of the heating section is calculated jg ;

[0179] The enthalpy value h at the inlet of the heating section jg , the mathematical expression is:

[0180] h jg = Δh + h in

[0181] In the step S8: Based on the enthalpy value h at the inlet of the heating section jg and the inlet pressure P in , the inlet temperature T of the heating section is calculated jg ;

[0182] The inlet temperature T of the heating section jg, the mathematical expression is:

[0183] T jg = f(P in , h jg ).

[0184] The present invention also provides a fuel assembly CHF test critical power and inlet temperature correction system, and the fuel assembly CHF test critical power and inlet temperature correction system can be realized by executing the process steps of the fuel assembly CHF test critical power and inlet temperature correction method, that is, those skilled in the art can understand the fuel assembly CHF test critical power and inlet temperature correction method as a preferred embodiment of the fuel assembly CHF test critical power and inlet temperature correction system.

[0185] According to a fuel assembly CHF test critical power and inlet temperature correction system provided by the present invention, it includes:

[0186] Module M1: Obtain the test data in the original data table;

[0187] Module M2: Based on the test data, confirm the qualitative temperature of the nickel rod;

[0188] Module M3: Based on the qualitative temperature, obtain the resistivity ρ;

[0189] Module M4: Based on the resistivity ρ, obtain the resistance value R;

[0190] Module M5: Based on the test data and the resistance value R, obtain the test critical power P jg , and perform correction;

[0191] Module M6: Based on the test data and the test power, obtain the enthalpy rise Δh of the nickel rod; based on the test data, calculate the enthalpy value h of the nickel rod in ;

[0192] Module M7: According to the enthalpy rise Δh and the enthalpy value h obtained by Module M6 in , calculate the inlet enthalpy value h of the heating section of the nickel rod jg ;

[0193] Module M8: Based on the inlet enthalpy value h of the heating section of the nickel rod jg and the test data, calculate the inlet temperature T of the heating section of the nickel rod jg , and complete the correction.

[0194] Specifically, the nickel rod is divided into four parts from top to bottom, which are: the upper nickel section, the heating section, the lower nickel tube section, and the lower copper tube section;

[0195] In the module M1:

[0196] The test data includes: inlet temperature T in , inlet pressure P in , outlet pressure P out , inlet flow rate Q m , and the test CHF power P as the test power;

[0197] In the module M2:

[0198] The qualitative temperature includes: T t , T nx , T jr and T ns , and the mathematical expression is:

[0199] T t is the normal temperature

[0200] T nx = T in

[0201] T ns = f(P out )

[0202] T jr = (T nx + T ns ) / 2

[0203] wherein, T t is the qualitative temperature of the lower copper tube section, T nx is the qualitative temperature of the lower nickel tube section, T ns is the qualitative temperature of the upper nickel rod, f represents the fluid property query function, and T jr is the qualitative temperature of the heating section.

[0204] Specifically, in the module M3:

[0205] The resistivity ρ includes: ρ ns , ρ jg , ρ nx , ρ t , and the mathematical expression is:

[0206] ρ = f(T)

[0207] ρ ns = f(T ns )

[0208] ρ jg = f(T jr )

[0209] ρ nx = f(T nx )

[0210] ρ t= f(T t )

[0211] where T is the temperature, ρ ns is the resistivity of the upper nickel rod, ρ jg is the resistivity of the heating section, ρ nx is the resistivity of the lower nickel tube section, ρ t is the resistivity of the lower copper tube section;

[0212] In the module M4:

[0213] According to the resistivity, the resistance value R is obtained; the resistance value R includes: R ns 、R jg 、R nx 、R t ;

[0214] R = ρ×l / s

[0215] R ns = ρ ns ×l / s

[0216] R jg = ρ jg ×l / s

[0217] R nx = ρ nx ×l / s

[0218] R t = ρ t ×l / s

[0219] where l is the axial length of each nickel tube section and s is the cross-sectional area of each nickel tube section;

[0220] where R ns is the resistance of the upper nickel rod, R jg is the resistance of the heating section, R nx is the resistance of the lower nickel tube section, R t is the resistance of the lower copper tube section.

[0221] Specifically, in the module M5: According to the test CHF power P and the resistance values of each section of the nickel rod, the corrected power, that is, the test critical power P jg and the power P of the lower nickel section nx ;

[0222] The test critical power P jg , the mathematical expression is:

[0223] P jg = P×R jg / (R ns +R jg +Rnx +R t )

[0224] The power P of the lower nickel section nx , the mathematical expression is:

[0225] P nx = P × R nx / (R ns + R jg + R nx + R t ).

[0226] Specifically, in the module M6: According to the inlet flow rate Q m and the power P of the lower nickel section nx , the enthalpy rise Δh of the lower nickel tube section is obtained; According to the inlet temperature T in and the inlet pressure P in , the enthalpy value h of the lower nickel tube is calculated in ;

[0227] The enthalpy rise Δh of the lower nickel tube section, the mathematical expression is:

[0228] Δh = P nx / Q m

[0229] The enthalpy value h at the inlet of the lower nickel tube in , the mathematical expression is:

[0230] h in = f(P in , T in )

[0231] In the module M7: According to the enthalpy rise Δh of the lower nickel tube section and the enthalpy value h at the inlet of the lower nickel tube obtained in the module M6 in , the enthalpy value h at the inlet of the heating section is calculated jg ;

[0232] The enthalpy value h at the inlet of the heating section jg , the mathematical expression is:

[0233] h jg = Δh + h in

[0234] In the module M8: Based on the enthalpy value h at the inlet of the heating section jg and the inlet pressure P in , the inlet temperature T of the heating section is calculated jg ;

[0235] The inlet temperature T of the heating section jg , the mathematical expression is:

[0236] T jg = f(P in , h jg ).

[0237] Those skilled in the art know that in addition to implementing the system, its various devices, modules, and units provided by the present invention in the form of pure computer-readable program code, the method steps can be logically programmed to enable the system, its various devices, modules, and units provided by the present invention to be implemented in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers, embedded microcontrollers, etc. to achieve the same functions. Therefore, the system and its various devices, modules, and units provided by the present invention can be regarded as a kind of hardware component, and the devices, modules, and units included therein for implementing various functions can also be regarded as the structures within the hardware component; the devices, modules, and units for implementing various functions can also be regarded as software modules for implementing the method and the structures within the hardware component.

[0238] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present application.

[0239] The specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essence of the present invention. Without conflict, the embodiments of the present application and the features in the embodiments can be combined with each other arbitrarily.

Claims

1. A method for correcting the critical power and inlet temperature of a fuel assembly CHF test, characterized in that including: Step S1: Obtain the test data in the original data table; Step S2: Based on the test data, confirm the qualitative temperature of the nickel rod; Step S3: Based on the qualitative temperature, obtain the resistivity ρ; Step S4: Based on the resistivity ρ, obtain the resistance value R; Step S5: Obtain the test critical power P based on the test data and the resistance value R jg , and perform correction; Step S6: Obtain the enthalpy rise Δh of the nickel rod based on the test data and the test power; calculate the enthalpy value h of the nickel rod based on the test data in ; Step S7: Based on the enthalpy rise Δh and the enthalpy value h obtained in step S6 in , calculate the inlet enthalpy value h of the heating section of the nickel rod jg ; Step S8: Based on the inlet enthalpy value h of the heating section of the nickel rod jg and the test data, calculate the inlet temperature T of the heating section of the nickel rod jg , and complete the correction; The nickel rod is divided into four parts from top to bottom, namely: the upper nickel section, the heating section, the lower nickel tube section, and the lower copper tube section; In the said Step S1: The test data includes: inlet temperature T in , inlet pressure P in , outlet pressure P out , inlet flow rate Q m , and the test CHF power P which is the test power; In the said Step S2: The qualitative temperature includes: T t , T nx , T jr and T ns , and the mathematical expression is: T t is at normal temperature T nx = T in T ns = f(P out ) T jr = (T nx + T ns ) / 2 Among them, T t is the qualitative temperature of the lower copper tube section, T nx is the qualitative temperature of the lower nickel tube section, T ns is the qualitative temperature of the upper nickel rod, f represents the fluid physical property query function, T jr is the qualitative temperature of the heating section; In the said Step S3: The resistivity ρ includes: ρ ns , ρ jg , ρ nx , ρ t , and the mathematical expression is: ρ = f(T) ρ nd = f(T nd ) ρ jg = f(T jr ) ρ nx = f(T nx ) ρ t = f(T t ) where T is the temperature, ρ ns is the resistivity of the upper nickel rod, ρ jg is the resistivity of the heating section, ρ nx is the resistivity of the lower nickel tube section, ρ t is the resistivity of the lower copper tube section; In the said Step S4: Based on the resistivity, obtain the resistance value R; the resistance value R includes: R ns , R jg , R nx , R t ; R = ρ × l / s R ns = ρ ns × l / s R jg = ρ jg × l / s R nx = ρ nx × l / s R t = ρ t × l / s wherein, l is the axial length of each nickel tube section, and s is the cross-sectional area of each nickel tube section; Among them, R ns is the resistance of the upper nickel rod, R jg is the resistance of the heating section, R nx is the resistance of the lower nickel tube section, R t is the resistance of the lower copper tube section; In the step S5: According to the test CHF power P and the resistance values of each section of the nickel rod, the corrected power, that is, the test critical power P, is obtained jg and the power P of the lower nickel section nx ; The test critical power P jg , and the mathematical expression is: P jg = P × R jg / (R ns + R jg + R nx + R t ) The power P of the lower nickel segment nx , and the mathematical expression is: P nx = P × R nx / (R ns + R jg + R nx + R t )。 2. The critical power of the fuel assembly CHF test and the inlet temperature correction method according to claim 1, characterized in that In the step S6: according to the inlet flow rate Q m and the power P of the lower nickel section nx , the enthalpy rise Δh of the lower nickel tube section is obtained; according to the inlet temperature T in and the inlet pressure P in , the enthalpy value h of the lower nickel tube is calculated in ; The enthalpy rise Δh of the lower nickel tube section has a mathematical expression as follows: Δh = P nx / Q m The enthalpy value h at the inlet of the lower nickel tube in , and the mathematical expression is: h in = f(P in , T in ) In the step S7: according to the enthalpy rise Δh of the lower nickel tube section obtained in the step S6 and the enthalpy value h at the inlet of the lower nickel tube in , the enthalpy value h jg at the inlet of the heating section is calculated; The inlet enthalpy value h of the heating section jg , and the mathematical expression is: h jg = Δh + h in In the step S8: Based on the inlet enthalpy h jg and the inlet pressure P in , the inlet temperature T jg of the heating section is calculated; The inlet temperature T of the heating section jg , and the mathematical expression is: T jg = f(P in , h jg ).

3. A critical power and inlet temperature correction system for CHF tests of a fuel assembly, characterized in that, including: Module M1: Obtain the test data in the original data table; Module M2: Based on the test data, confirm the qualitative temperature of the nickel rod; Module M3: Based on the qualitative temperature, obtain the resistivity ρ; Module M4: Based on the resistivity ρ, obtain the resistance value R; Module M5: Based on the test data and the resistance value R, obtain the test critical power P jg , and make corrections; Module M6: Obtain the enthalpy rise Δh of the nickel rod based on the test data and test power; calculate the enthalpy value h of the nickel rod based on the test data in ; Module M7: Based on the enthalpy rise Δh and enthalpy value h obtained from Module M6 in , calculate the inlet enthalpy value h of the heating section of the nickel rod jg ; Module M8: Based on the inlet enthalpy h of the heating section of the nickel rod jg and the test data, calculate the inlet temperature T of the heating section of the nickel rod jg , and complete the correction; The nickel rod is divided into four parts from top to bottom, namely: the upper nickel section, the heating section, the lower nickel tube section, and the lower copper tube section; In the said Module M1: The test data includes: inlet temperature T in , inlet pressure P in , outlet pressure P oiy , inlet flow rate Q m , and the test CHF power P as the test power; In the said Module M2: The qualitative temperature includes: T t , T nx , T jr and T ns , and the mathematical expression is: T t is at room temperature T nx = T in T ns = f(P out ) T jr = (T nx + T ns ) / 2 Among them, T t is the qualitative temperature of the lower copper tube section, T nx is the qualitative temperature of the lower nickel tube section, T ns is the qualitative temperature of the upper nickel rod, f represents the fluid physical property query function, T jr is the qualitative temperature of the heating section; In the said Module M3: The resistivity ρ includes: ρ ns , ρ jg , ρ nx , ρ t , and the mathematical expression is: ρ = f(T) ρ ns = f(T ns ) ρ jg = f(T jr ) ρ nx = f(T nx ) ρ t = f(T t ) where T is the temperature, ρ ns is the resistivity of the upper nickel rod, ρ jg is the resistivity of the heating section, ρ nx is the resistivity of the lower nickel tube section, ρ t is the resistivity of the lower copper tube section; In the said Module M4: Based on the resistivity, obtain the resistance value R; the resistance value R includes: R ns , R jg , R nx , R t ; R = ρ × l / s R ns = ρ ns × l / s R jg = ρ jg × l / s R nx = ρ nx × l / s T t = ρ t × l / s wherein, l is the axial length of each nickel tube section, and s is the cross-sectional area of each nickel tube section; Among them, R ns is the resistance of the upper nickel rod, R jg is the resistance of the heating section, R nx is the resistance of the lower nickel tube section, R t is the resistance of the lower copper tube section; In the module M5: According to the test CHF power P and the resistance values of each section of the nickel rod, the corrected power, i.e., the test critical power P jg and the power P of the lower nickel section nx ; The test critical power P jg , and the mathematical expression is: P jg = P × R jg / (R ns + R jg + R nx + R t ) The power P of the lower nickel section nx , and the mathematical expression is: P nx = P × R nx / (R ns + R jg + R nx + R t )。 4. The critical power and inlet temperature correction system for CHF tests of a fuel assembly according to claim 3, characterized in that, In the module M6: Based on the inlet flow rate Q m and the power P of the lower nickel section nx , the enthalpy rise Δh of the lower nickel tube section is obtained; Based on the inlet temperature T in and the inlet pressure P in , the enthalpy value h of the lower nickel tube is calculated in ; The enthalpy rise Δh of the lower nickel tube section has a mathematical expression as follows: Δh = P nx / Q m The enthalpy value h of the inlet of the lower nickel tube in , and the mathematical expression is: h in = f(P in , T in ) In the module M7: According to the enthalpy rise Δh of the lower nickel tube section obtained in the module M6 and the enthalpy value h at the inlet of the lower nickel tube in , the enthalpy value h at the inlet of the heating section is calculated jg ; The enthalpy value h at the inlet of the heating section jg , and the mathematical expression is: h jg = Δh + h in In the module M8: Based on the inlet enthalpy h jg and the inlet pressure P in , the inlet temperature T jg of the heating section is calculated; The inlet temperature T of the heating section jg , and the mathematical expression is: T jg = f(P in , h jg ).

Images