Active cooling dynamic thermal management method for high-temperature lattice sandwich structure

Abstract

The invention discloses a high-temperature dot matrix sandwich structure active cooling dynamic thermal management method, which is based on a high-temperature dot matrix sandwich structure active cooling dynamic thermal management system, and the system comprises an active cooling dot matrix sandwich structure, a temperature unit, an outer substrate outer side temperature index setting unit, a resolving unit and a coolant control unit. The method comprises the steps of setting a dynamic management target based on a high-temperature environment dot matrix sandwich structure, setting a dynamic thermal management time interval t0, initializing t to be equal to 0, starting to time t, and executing a program when t is equal to t0; the temperature field prediction subunit predicts temperature field distribution Tex, 1, the flow prediction subunit obtains the coolant flow # imgabs 0 # which finally meets the target requirement, the control opening degree of a flow regulating valve of a coolant control unit is controlled, and the corresponding coolant flow # imgabs 1 # is released. And the quick response to the temperature change is realized.

Description

Technical Field

[0001] The present invention belongs to the technical field of thermal protection of aerospace vehicles, and in particular relates to a dynamic thermal management method for active cooling of a high-temperature lattice sandwich structure. Background Art

[0002] Actively cooled TPS (Thermal Protection Systems) is the inevitable choice for major components in the fields of machinery, aerospace, etc. that are subjected to high heat flux density and long-term service. The lattice sandwich structure is a lightweight and high-strength structure composed of inner and outer substrates and an intermediate lattice core. The scramjet engine has to withstand high temperatures of 2000-3000K and a pressure of 2MPa when Ma=6-8. Among them, the high temperature problem of the extreme thermal environment puts extremely high demands on the temperature resistance and strength of the inner layer material of the combustion chamber. The service temperature of high-temperature alloys does not exceed 2000K (such as GH-4169 is 1255K). Using ceramic-based composite materials as the inner substrate of the combustion chamber and using high-temperature alloys as the lattice core and outer substrate can effectively reduce the mass of TPS and improve the connection performance with external components, and meet the manufacturing process constraints, making the application of lattice structures in high-temperature environments possible.

[0003] The existing active cooling TPS of the lattice interlayer cannot respond to the temperature in time. The so-called timely response to temperature means that at a given combustion chamber temperature T w Under these conditions, it's impossible to immediately determine the expected coolant flow rate through the cooling channels to reduce the outer wall temperature to a specified range. Using computational fluid dynamics (CFD) methods is only suitable for the initial design phase, which is time-consuming and unlikely to be used during engine service. This creates difficulties in designing active cooling systems (TPSs) with lattice interlayers and in dynamically managing temperatures during actual use. Summary of the Invention

[0004] In view of the problems existing in the prior art, the present invention proposes a high-temperature lattice sandwich structure active cooling dynamic thermal management method, which aims to solve the problem that the existing lattice sandwich active cooling TPS cannot respond to temperature in a timely manner.

[0005] The present invention adopts the following technical solutions to solve the technical problems:

[0006] A dynamic thermal management method for active cooling of high-temperature lattice sandwich structures is based on a

[0007] A high-temperature lattice sandwich structure active cooling dynamic thermal management system, the system includes an active cooling lattice sandwich structure, a temperature unit, an external substrate outer temperature index setting unit, a solution unit, and a coolant control unit;

[0008] The solution unit is provided with a temperature field prediction subunit and a flow prediction subunit; the temperature unit is provided with an outer substrate outer side temperature prediction subunit and an inner substrate outer side temperature monitoring subunit; the inner substrate outer side temperature monitoring subunit is arranged on the outer side of the inner substrate of the active cooling lattice sandwich structure, and the outer substrate outer side temperature prediction subunit is obtained by prediction by the temperature field prediction subunit; the coolant control unit is provided with a coolant flow monitoring subunit, a coolant pressure monitoring subunit, a coolant temperature monitoring subunit, a coolant flow control subunit, and a coolant storage subunit; the coolant control unit is arranged at the inlet of the coolant flow channel of the lattice sandwich structure; the outer substrate outer side temperature index setting unit and the solution unit are respectively arranged on a computer;

[0009] The input end of the active cooling sandwich structure is connected to the coolant storage unit, and the output end is connected to the inner substrate outer temperature monitoring subunit; the input end of the solution unit is respectively connected to the outer substrate outer temperature indicator unit, the inner substrate outer temperature monitoring subunit, the coolant flow monitoring subunit, the coolant pressure monitoring subunit, and the coolant temperature monitoring subunit, and the output end is connected to the coolant flow control subunit; the input end of the coolant control unit is connected to the flow prediction subunit, and the output end is connected to the active cooling sandwich structure; the input ends of the coolant flow monitoring subunit, the coolant pressure monitoring subunit, and the coolant temperature monitoring subunit are respectively connected to the coolant storage subunit, and the output ends are connected to the flow prediction subunit;

[0010] The method is characterized in that it comprises the following steps:

[0011] Step 1: Set a dynamic management target based on a high-temperature lattice sandwich structure, set a dynamic thermal management time interval t0, initialize t to t=0, and start timing t. When t=t0, execute step 2.

[0012] Step 2: The temperature field prediction subunit predicts the temperature field distribution T ex,1 , the flow prediction subunit obtains the coolant flow that ultimately meets the target requirements

[0013] Step 3: The coolant control unit flow regulating valve controls the opening to release the corresponding coolant flow.

[0014] Step 4. Return to step 1.

[0015] The setting of step 1 is based on the dynamic management target of the high-temperature lattice sandwich structure, and the dynamic management target is specifically:

[0016] T ex,0 =(T ex,0,1 ,T ex,0,2 ,…T ex,0,n ) (1)

[0017] In formula (1), T ex,0 is the known quantity, T ex,0 is the axial distribution of the target service temperature outside the outer substrate, i represents the i-th lattice sandwich structure cell along the axial direction, T ex,0,i is the average temperature of the i-th lattice sandwich structure cell, and n is the total number of lattice sandwich structure cells along the axial direction;

[0018] The temperature field prediction subunit in step 2 predicts the temperature field distribution T ex,1 , the flow prediction subunit obtains the coolant flow that ultimately meets the target requirements The details are as follows:

[0019] 1) The temperature field prediction subunit obtains the actual temperature T of the inner substrate outer side measured by the inner substrate outer side temperature monitoring subunit w ;

[0020] T w =(T w,1 ,T w,2 ,…T w,n ) (2)

[0021] T on the left side of formula (2) w is the axial distribution of the temperature outside the inner substrate, T w is the known quantity measured by the temperature monitoring subunit of the inner substrate and outer substrate; T on the right side of formula (2) w,i is the average temperature of the i-th lattice sandwich structure cell.

[0022] 2) Temperature field prediction subunit is based on T w and T ex,0 The temperature distribution and the current given coolant flow rate Calculate the predicted temperature distribution T outside the outer substrate at the yth iteration ex,1 ;

[0023] 3) The traffic prediction subunit contains T ex,1 Formula (3) determines Whether the target requirements are met:

[0024]

[0025] in, is the coolant flow rate given by the yth iteration; T ex,1 The temperature of any cell in the lattice sandwich structure is less than or equal to T ex,0 The corresponding temperature in: error is the threshold constant set according to the iteration target; the first sub-formula in formula (3) represents the actual temperature T of any cell in the axial direction of the lattice sandwich structure ex,1,i are all lower than the target temperature Tex,0,i The second sub-formula in formula (3) indicates the target temperature T of a cell in the axial direction of the lattice sandwich structure. ex,0,i With the actual temperature T ex,1,i The difference is less than or equal to the threshold error.

[0026] 4) Iteration Output flow that meets target requirements The specific steps are as follows:

[0027] i. When the predicted temperature distribution T ex,1 When formula (3) is satisfied, the set flow rate Output flow

[0028] ii. When the predicted temperature distribution T ex,1 When formula (3) is not satisfied, the flow prediction subunit calculates the coolant flow for the y+1th iteration And return to process 2) Give the temperature field prediction subunit.

[0029] The temperature field prediction subunit in step 2) is based on T w and T ex,0 The temperature distribution and the current given coolant flow rate Calculate the predicted temperature distribution T on the outside of the outer substrate at the yth iteration ex,1 , as follows:

[0030] ⑴. Establish the thermal balance equation of the inner substrate:

[0031] F1=E w-d +E bar-d +E f-d +E d,rad =0 (4)

[0033] In formula (4), F1 represents the thermal balance equation of the inner substrate, E w-d is the heat conduction heat flow outside the inner substrate; E bar-d is the heat conduction heat flux between the inner substrate and the rod; E f-d is the convective heat flow between the coolant and the inner substrate; E d,rad is the net radiation heat flux inside the inner substrate;

[0034] E in formula (4) w-d , E bar-d , E f-d and E d,bar All are unknown quantities T d,i , T bar,i , T u,i and the known quantity Tw,i , T i Function of T d,i is the inner substrate temperature, T bar,i is the rod temperature, T u,i is the temperature inside the outer substrate, T i is the coolant inlet temperature of the i-th lattice sandwich structure cell, which is calculated from the outlet temperature of the i-1-th lattice sandwich structure cell;

[0035] ⑵、Establish the thermal balance equation of rod temperature:

[0036]

[0037] Where F2 represents the heat balance equation of the rod temperature; the first term on the right side of formula (5) represents the conduction heat flux gradient at the local coordinate x, the second term on the right side of formula (5) represents the convective heat flux at the local coordinate x, T i is the coolant inlet temperature of the i-th lattice sandwich structure cell, and the axial direction of the rod is the x direction of the rod; the conduction heat flux gradient at the local coordinate x = the convective heat flux at the local coordinate x ÷ the cross-sectional area of the rod; since the total radiation heat flux density on the rod surface is small relative to the convective heat flux density, the radiation heat flux E in formula (4) is d,rad Not considered;

[0038] In formula (5), k s (T bar ) is the thermal conductivity of the lattice material and is the rod temperature T bar,i Function of P bar is the cross-sectional perimeter of the member; A bar is the cross-sectional area of the rod; h ∞，bar is the local convection heat transfer coefficient of the rod.

[0039] In formula (5), k s , P bar , A bar , h ∞,bar and T i are all known quantities, T bar,i is an unknown quantity.

[0040] ⑶. Establish the thermal balance equation of the external substrate temperature:

[0041] F3=E d-u +E f-u +E bar-u =0 (6)

[0043] Among them, F3 represents the thermal balance equation of the external substrate temperature, E d-uis the net radiation heat flow from the inner side of the inner substrate to the outer substrate; E f-d is the heat flow of convective heat transfer between the coolant and the external substrate; E bar-u is the conduction heat flux between the outer base plate and the rod;

[0044] E in formula (6) d-u , E f-u , E f-d and E bar-u All are unknown quantities T d,i , T bar,i , T u,i and the known quantity T i function.

[0045] ⑷、Use the unknown quantity T in formula (4)(5)(6) d,i ,T bar,i ,T u,i The general expression is F j =

[0046] F j (T d,i ,T bar,i ,T u,i ), due to T in (4)(5)(6) i is a known quantity, so F j is the unknown quantity T d,i , T bar,i , T u,i and the known quantity T i function.

[0047] The heat flux in the above equations (4) and (6) can be generalized to be expressed as E=

[0048] E(T d,i , T bar,i ,T u,i ,T i ), since the thickness of the outer substrate is generally very small and the material with high thermal conductivity is used, the temperature inside and outside the outer substrate is considered to be the same, that is, T u,i =T ex,1,i , so, E=E(T d,i , T bar,i ,T ex,1,i ,T i ), and (4) only has T bar,i is an unknown number, so we can write F1=F1(T d,i , T bar,i ,T ex,1,i ,T i ), F2=F2(T bar,i ,T i )and

[0049] F3=F3(T d,i , T bar,i ,T ex,i ,T i ), so formulas (4)(5)(6) can be generalized as F j =

[0050] F j (T d,i ,T bar,i ,T ex,1,i ,T i )j∈{1,2,3};

[0051] ⑸、Transform the above equation F j Combined to establish the solution of unknown quantities in the solid temperature field

[0052] T=(T d,i ,T bar,i ,T ex,1,i );

[0053] F(T,T i )=F(T d,i ,T bar,i ,T ex,1,i ,T i )=0 (7)

[0054] Where F = [F1 F2 F3] T , iteratively solve formula (7) to obtain the unknown quantity of solid temperature field T = (T d,i ,T bar,i ,T ex,1,i ) is a numerical solution of .

[0055] (6) Calculate the coolant temperature T at the outlet of the i-th cell of the lattice sandwich structure based on the solved unknown quantity T of the solid temperature field i+1 , the coolant temperature balance equation at the inlet and outlet of each cell of the lattice sandwich structure is obtained:

[0056]

[0057] Where, formula (8) removes T i+1 are all known quantities, is the given coolant mass flow rate at the yth iteration, C p The specific heat of the coolant is a known quantity, E f-d , E f-u and E f-bar In process (5), by solving T = (T d,i ,T bar,i ,T ex,1,i ) has been obtained and is a known quantity. Solving formula (8) yields T i+1Therefore, the method of solving the unknown quantity T of the solid temperature field in the i-th cell of the next lattice sandwich structure (i+1th) can be used in the same way as in the above formulas (4)-(7), and the numerical solutions of T of all lattice sandwich structure cells along the axial direction can be obtained in turn, thereby calculating the predicted temperature distribution T of the outer side of the outer substrate of all cells of the lattice sandwich structure. ex,1 .

[0058] The process of step 2 4) in step ii when the predicted temperature distribution T ex,1 When formula (3) is not satisfied, the flow prediction subunit calculates the coolant flow for the y+1th iteration The details are as follows:

[0059] ① The first case: For the predicted temperature T that does not satisfy the first sub-formula of formula (3) ex,1,i are all lower than the target temperature T ex,0,i situation, that is:

[0060]

[0061] The coolant mass flow rate is:

[0062]

[0063] Formula (9) indicates that there is a temperature T somewhere outside the outer substrate. ex,1,i Specific temperature index T ex,0,i High; Formula (10) represents the next coolant mass flow = Coolant mass flow rate of the previous iteration +(the minimum mass flow rate that satisfies the first sub-formula of formula (3) during the historical iteration process -The maximum mass flow rate that satisfies formula (9) during the historical iteration process ) / 2,

[0064] ② The second case: For any location that does not satisfy the second sub-formula of formula (3), the predicted temperature T ex,0,i -T ex,1,i are all greater than the threshold error, that is:

[0065]

[0066] Then: The coolant mass flow rate is:

[0067]

[0068] Formula (11) represents the index temperature T at any point outside the outer substrate: ex,0,i -Predicted temperature T ex,1,i When the coolant mass flow rate is greater than the threshold value, formula (12) indicates the next coolant mass flow rate. = Coolant mass flow rate of the previous iteration -(Minimum mass flow rate that satisfies formula (11) during the historical iteration process -The maximum mass flow rate that satisfies formula (9) during the historical iteration process ) / 2.

[0069] The coolant control unit flow regulating valve in step 3 controls the opening to release the corresponding coolant flow The specific process is as follows: the flow prediction subunit obtains the coolant flow that ultimately meets the requirements of formula (3) And send it to the active cooling lattice sandwich structure through the coolant control module.

[0070] Advantages and effects of the present invention

[0071] 1. The dynamic thermal management system comprehensively considers the complex coupling of radiation, convection and conduction within the TPS under high-temperature environments, as well as the change of thermal conductivity with temperature, which conforms to real high-temperature physical scenarios.

[0072] 2. The patented dynamic thermal management system uses a fast prediction program to regulate the active cooling TPS coolant flow in real time, obtain the structural temperature field, and keep each part within a safe temperature range, achieving a rapid response to temperature changes.

[0073] 3. The dynamic thermal management system of this patent is aimed at high-temperature active cooling lattice sandwich structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0074] Figure 1 This is a schematic diagram of the temperature of the inner wall of the combustion chamber of the present invention;

[0075] Figure 2 This is a block diagram of the high-temperature lattice sandwich structure active cooling dynamic thermal management system of the present invention;

[0076] Figure 3 This is a flow chart of the active cooling dynamic thermal management method for a high-temperature lattice sandwich structure of the present invention. DETAILED DESCRIPTION

[0077] 1. Innovations of the Present Invention: One innovation lies in the establishment of a dynamic thermal management system and method. Existing technologies using computational fluid dynamics methods are only applicable in the initial design phase. Due to the time-consuming calculation process, they cannot be used during the dynamic operation of an engine. The present invention's dynamic thermal management system uses a rapid prediction program to regulate the coolant flow of the active cooling system (TPS) in real time, obtaining the structural temperature field and maintaining each component within a safe temperature range. This allows for rapid response to temperature changes, thus meeting the requirements for real-time control of lattice sandwich structures. A second innovation lies in the construction of a system that comprehensively considers the complex coupling of radiation, convection, and conduction within the TPS under high-temperature conditions, as well as the temperature-dependent changes in thermal conductivity, conforming to realistic high-temperature physics scenarios.

[0078] 2. Several key points of the present invention:

[0079] The first key point: establish the target temperature field index of formula (1);

[0080] The second key point: the temperature field T outside the outer substrate of the lattice sandwich structure ex,1,i Two requirements must be met at the same time: it must be lower than the target temperature field, but it must not exceed the threshold, that is, the T of each cell of the lattice sandwich structure. ex,0,i -T ex,1,i The difference should not be too large, but should be controlled within the threshold range;

[0081] The third key point: The thermal balance equations (4), (5), and (6) lay a scientific foundation for the real-time response of the active cooling TPS of the lattice sandwich structure. The scientific foundation is that the dynamic thermal management system comprehensively considers the complex coupling of radiation, convection, and conduction in the TPS under high temperature conditions, as well as the change of thermal conductivity with temperature, which conforms to the real high-temperature physical scenario. The comprehensive consideration of the complex coupling of radiation, convection, and conduction in the TPS under high temperature conditions, as well as the change of thermal conductivity with temperature, is: Formula (4) takes into account the heat conduction heat flux E on the outside of the inner substrate. w-d ; Heat conduction heat flux E between the inner substrate and the rod bar-d ; Convective heat flux E between coolant and inner substrate f-d ; Net radiation heat flux E on the inner side of the inner substrate d,rad Formula (5) takes into account the conduction heat flux density gradient at the local coordinate x of the rod and the convection heat flux density at the local coordinate x of the rod; Formula (6) takes into account the net radiation heat flux E from the inner side of the inner substrate to the outer substrate d-u ; Convection heat transfer heat flow E between coolant and external substrate f-d ; Heat conduction flux E between the outer base plate and the rod bar-u ;

[0082] The fourth key point: Iterate to get the traffic that meets the target requirements The iterative method is: when the predicted temperature distribution T ex,1 When formula (3) is not satisfied: ① First give a known ②Use the Get a corresponding T ex,1 ; ③ Use T ex,1 Compare with the sub-formula 1 and sub-formula 2 of formula (3); ④ For the first case that does not meet the requirements of formula (3), calculate a suitable And for the second case that does not meet the requirements of formula (3), calculate a suitable ⑤According to Get a new T i+1 ⑥Use new T i+1 Substitute the known quantity into formula (4)-(7) to obtain the predicted temperature distribution T outside the outer substrate. ex,1 Repeat the above process to finally obtain a predicted temperature distribution T on the outside of the outer substrate. ex,1 The cooling flow rate that meets the requirements of formula (3) Will Output to the lattice sandwich structure.

[0083] Based on the above principles, Figure 1-3 As shown, the present invention designs a high-temperature lattice sandwich structure active cooling dynamic thermal management method, which is based on a high-temperature lattice sandwich structure active cooling dynamic thermal management system, such as Figure 2 As shown, the system includes an active cooling lattice sandwich structure, a temperature unit, an outer substrate outer temperature index setting unit, a solution unit, and a coolant control unit;

[0084] The solution unit is provided with a temperature field prediction subunit and a flow prediction subunit; the temperature unit is provided with an outer substrate outer temperature prediction subunit and an inner substrate outer temperature monitoring subunit; the inner substrate outer temperature monitoring subunit is arranged on the outer side of the inner substrate of the active cooling lattice sandwich structure, and the outer substrate outer temperature prediction subunit is predicted by the temperature field prediction subunit; the coolant control unit is provided with a coolant flow monitoring subunit, a coolant pressure monitoring subunit, a coolant temperature monitoring subunit, a coolant flow control subunit, and a coolant storage subunit; the coolant control unit is arranged at the inlet of the coolant flow channel of the lattice sandwich structure; the outer substrate outer temperature index setting unit and the solution unit are respectively arranged on a computer;

[0085] The input end of the active cooling sandwich structure is connected to the coolant storage unit, and the output end is connected to the inner substrate outer temperature monitoring subunit; the input end of the solution unit is respectively connected to the outer substrate outer temperature indicator unit, the inner substrate outer temperature monitoring subunit, the coolant flow monitoring subunit, the coolant pressure monitoring subunit, and the coolant temperature monitoring subunit, and the output end is connected to the coolant flow control subunit; the input end of the coolant control unit is connected to the flow prediction subunit, and the output end is connected to the active cooling sandwich structure; the input ends of the coolant flow monitoring subunit, the coolant pressure monitoring subunit, and the coolant temperature monitoring subunit are respectively connected to the coolant storage subunit, and the output ends are connected to the flow prediction subunit;

[0086] The method is characterized in that it comprises the following steps:

[0087] Step 1: Set a dynamic management target based on a high-temperature lattice sandwich structure, set a dynamic thermal management time interval t0, initialize t to t=0, and start timing t. When t=t0, execute step 2.

[0088] like Figure 1 As shown in the figure, the dynamic management objectives are:

[0089] T ex,0 =(T ex,0,1 ,T ex,0,2 ,…T ex,0,n ) (1)

[0090] In formula (1), T ex,0 is the known quantity, T ex,0 is the axial distribution of the target service temperature outside the outer substrate, i represents the i-th lattice sandwich structure cell along the axial direction, T ex,0,i is the average temperature of the i-th lattice sandwich structure cell, and n is the total number of lattice sandwich structure cells along the axial direction;

[0091] Supplementary Note 1: Composition of the lattice sandwich structure

[0092] ① Such as Figure 1 The figure shows a schematic diagram of a lattice sandwich structure, which consists of an inner base plate, an outer base plate, and a rod in the middle; w The temperature data of the inner and outer sides of the substrate measured by the temperature sensor, T ex,0 is the target service temperature; T ex,1 To predict the temperature field distribution T ex,1 ;

[0093] ②The predicted temperature field distribution T ex,1 The design requirement is: it must be lower than the target temperature T ex,0, and cannot be much lower than the target temperature; that is, it must meet the requirements of sub-equations 1 and 2 of formula (3). The temperature sensor is the sub-unit for monitoring the temperature of the inner substrate and outer surface of the temperature unit. Sub-equation 1 is the first line of formula (3); Sub-equation 2 is the second line of formula (3);

[0094] Step 2: The temperature field prediction subunit predicts the temperature field distribution T ex,1 , the flow prediction subunit obtains the coolant flow that ultimately meets the target requirements The details are as follows:

[0095] 1) The temperature field prediction subunit obtains the actual temperature T of the inner substrate outer side measured by the inner substrate outer side temperature monitoring subunit w ;

[0096] T w =(T w,1 ,T w,2 ,…T w,n ) (2)

[0097] T on the left side of formula (2) w is the axial distribution of the temperature outside the inner substrate, T w is the known quantity measured by the temperature monitoring subunit of the inner substrate and outer substrate; T on the right side of formula (2) w,i is the average temperature of the i-th lattice sandwich structure cell.

[0098] 2) Temperature field prediction subunit is based on T w and T ex,0 The temperature distribution and the current given coolant flow rate Calculate the predicted temperature distribution T outside the outer substrate at the yth iteration ex,1 , as follows:

[0099] Supplementary Note 2: Obtain the temperature distribution field T of all cells ex,1

[0100] ① The following formulas (4), (5), (6) and (7) are all used to obtain the temperature distribution field T of the i-th cell: ex,1,i , unknown quantity T d,i , T bar,i , T u,i and the known quantity T i The function of T i is the coolant inlet temperature of the i-th lattice sandwich structure cell;

[0101] ②Through equation F j Combined, we get T=(T d,i ,T bar,i ,T ex,1,i ) numerical solution;

[0102] ③ Solve formula (8) to get the new T i =T i+1 ;

[0103] ④ Repeat formula (4)-(7). During the execution, the T obtained by formula (8) i+1 Substitute the known quantity T i Finally, the predicted temperature distribution field T of all elements along the sandwich structure is obtained. ex,1

[0104] ⑴. Establish the thermal balance equation of the inner substrate:

[0105] F1=E w-d +E bar-d +E f-d +E d,rad =0 (4)

[0106] In formula (4), F1 represents the thermal balance equation of the inner substrate, E w-d is the heat conduction heat flow outside the inner substrate; E bar-d is the heat conduction heat flux between the inner substrate and the rod; E f-d is the convective heat flow between the coolant and the inner substrate; E d,rad is the net radiation heat flux inside the inner substrate;

[0107] E in formula (4) w-d , E bar-d , E f-d and E d,bar All are unknown quantities T d,i , T bar,i , T u,i and the known quantity T w,i , T i Function of T d,i is the inner substrate temperature, T bar,i is the rod temperature, T u,i is the temperature inside the outer substrate; T i is the coolant inlet temperature of the i-th lattice sandwich structure cell, which is calculated from the outlet temperature of the i-1-th lattice sandwich structure cell;

[0108] ⑵、Establish the thermal balance equation of rod temperature:

[0109]

[0110] Where F2 represents the heat balance equation of the rod temperature; the first term on the right side of formula (5) represents the conduction heat flux gradient at the local coordinate x, the second term on the right side of formula (5) represents the convective heat flux at the local coordinate x, T iis the coolant inlet temperature of the i-th lattice sandwich structure cell, and the axial direction of the rod is the x direction of the rod; the conduction heat flux gradient at the local coordinate x = the convective heat flux at the local coordinate x ÷ the cross-sectional area of the rod; since the total radiation heat flux density on the rod surface is small relative to the convective heat flux density, the radiation heat flux E in formula (4) is d,rad Not considered;

[0111] In formula (5), k s (T bar ) is the thermal conductivity of the lattice material and is the rod temperature T bar,i Function of P bar is the cross-sectional perimeter of the member; A bar is the cross-sectional area of the rod; h ∞,bar is the local convection heat transfer coefficient of the rod.

[0112] In formula (5), k s , P bar , A bar , h ∞,bar and T i are all known quantities, T bar,i is an unknown quantity.

[0113] ⑶. Establish the thermal balance equation of the external substrate temperature:

[0114] F3=E d-u +E f-u +E bar-u =0 (6)

[0115] Among them, F3 represents the thermal balance equation of the external substrate temperature, E d-u is the net radiation heat flow from the inner side of the inner substrate to the outer substrate; E f-d is the heat flow of convective heat transfer between the coolant and the external substrate; E bar-u is the conduction heat flux between the outer base plate and the rod; E in formula (6) d-u , E f-u , E f-d and E bar-u All are unknown quantities T d,i , T bar,i , T u,i and the known quantity T i function.

[0116] ⑷、Generalize formula (4)(5)(6) to express it as F i =F i (T d,i ,T bar,i ,T u,i ), specifically: F j =F j (T d,i ,Tbar,i ,T u,i ), due to T in (4)(5)(6) i is a known quantity, so F j is the unknown quantity T d,i , T bar,i , T u,i and the known quantity T i function.

[0117] The heat fluxes in the above equations (4) and (6) can be generalized to be expressed as E = E (T d,i ,T bar,i ,T u,i ), since the thickness of the outer substrate is generally very small and the material with high thermal conductivity is used, the temperature inside and outside the outer substrate is considered to be the same, that is, T u,i =T ex,1,i , so, E=E(T d,i ,T bar,i ,T ex,1,i ), and (4) only has T bar,i is an unknown number, so we can write F1=F1(T d,i , T bar,i ,T ex,1,i ),

[0118] F2=F2(T bar,i ) and F3=F3(T d,i , T bar,i ,T ex,i ), so formulas (4)(5)(6) can be generalized as F j =F j (T d,i ,T bar,i ,T ex,1,i )j∈{1,2,3};

[0119] ⑸、Transform the above equation F j Combined, used to establish the solution of the unknown quantity T=(T d,i ,T bar,i ,T ex,1,i );

[0120] F(T,T i )=F(T d,i ,T bar,i ,T ex,1,i ,T i ) (7)

[0121] Where F = [F1 F2 F3] T , iteratively solve formula (7) to obtain the unknown quantity of solid temperature field T = (T d,i ,T bar,i,T ex,1,i ) is a numerical solution of .

[0122] (6) Calculate the coolant temperature T at the outlet of the i-th cell of the lattice sandwich structure based on the solved unknown quantity T of the solid temperature field i+1 , the coolant temperature balance equation at the inlet and outlet of each cell of the lattice sandwich structure is obtained:

[0123]

[0124] Where, formula (8) removes T i+1 are all known quantities, is the given coolant mass flow rate at the yth iteration, C p The specific heat of the coolant is a known quantity, E f-d , E f-u and E f-bar In process (5), by solving T = (T d,i ,T bar,i ,T ex,1,i ) has been obtained and is a known quantity. Solving formula (8) yields T i+1 Therefore, the method of solving the unknown quantity T of the solid temperature field in the i-th cell of the next lattice sandwich structure (i+1th) can be used in the same way as in the above formulas (4)-(7), and the numerical solutions of T of all lattice sandwich structure cells along the axial direction can be obtained in turn, thereby calculating the predicted temperature distribution T of the outer side of the outer substrate of all cells of the lattice sandwich structure. ex,1 .

[0125] 3) The traffic prediction subunit contains T ex,1 Formula (3) determines Whether the target requirements are met:

[0126]

[0127] in, is the coolant flow rate given by the yth iteration; T ex,1 The temperature of any cell in the lattice sandwich structure is less than or equal to T ex,0 The corresponding temperature in: error is the threshold constant set according to the iteration target; the first sub-formula in formula (3) represents the actual temperature T of any cell in the axial direction of the lattice sandwich structure ex,1,i are all lower than the target temperature T ex,0,i The second sub-formula in formula (3) indicates the target temperature T of a cell in the axial direction of the lattice sandwich structure. ex,0,i With the actual temperature T ex,1,i The difference is less than or equal to the threshold error.

[0128] 4) Iteration Output flow that meets target requirements The specific steps are as follows:

[0129] i. When the predicted temperature distribution T ex,1 When formula (3) is satisfied, the set flow rate Output flow

[0130] ii. When the predicted temperature distribution T ex,1 When formula (3) is not satisfied, the flow prediction subunit calculates the coolant flow for the y+1th iteration And return to process 2) To the temperature field prediction subunit; the details are as follows:

[0131] ① The first case: For the predicted temperature T that does not satisfy the first sub-formula of formula (3) ex,1,i are all lower than the target temperature T ex,0,i situation, that is:

[0132]

[0133] The coolant mass flow rate is:

[0134]

[0135] Formula (9) Indicates that there is a temperature T somewhere outside the outer substrate ex,1,i Specific temperature index T ex,0,i High; Formula (10) represents the next coolant mass flow = Coolant mass flow rate of the previous iteration +(the minimum mass flow rate that satisfies the first sub-formula of formula (3) during the historical iteration process -The maximum mass flow rate that satisfies formula (9) during the historical iteration process ) / 2;

[0136] Supplementary Note 3: Regarding the first case that does not satisfy formula (3)

[0137] A. Formula (9) is the first case that does not satisfy Formula (3), that is: the temperature field T of the i-th cell after cooling ex,1,i Greater than the target temperature field T of the i-th cell ex,0,i In this case, the cooling flow rate needs to be increased, so the right side of formula (10) adopts the addition method.

[0138] B. Since formula (9) is that the current temperature field temperature is relatively high and does not meet the requirements of formula (3), the relatively high temperature is higher than the target value, that is, the relatively small cooling flow rate causes the relatively high temperature. Therefore, the formula (10) The minimum flow rate among the multiple flow rates corresponding to the current temperature field that satisfies the sub-formula 1 of formula (3) is selected; since formula (9) does not meet the requirements of formula (3) when the temperature is relatively low, the minimum flow rate in formula (10) is: The maximum mass flow rate that satisfies formula (9) during the historical iteration process should be selected;

[0139] ② The second case: For any location that does not satisfy the second sub-formula of formula (3), the predicted temperature T ex,0,i -T ex,1,i are all greater than the threshold error, that is:

[0140]

[0141] Then: The coolant mass flow rate is:

[0142]

[0143] Formula (11) represents the index temperature T at any point outside the outer substrate: ex,0,i -Predicted temperature T ex,1,i When the coolant mass flow rate is greater than the threshold value, formula (12) indicates the next coolant mass flow rate. = Coolant mass flow rate of the previous iteration -(Minimum mass flow rate that satisfies formula (11) during the historical iteration process -The maximum mass flow rate that satisfies formula (9) during the historical iteration process ) / 2.

[0144] Supplementary Note 4: Regarding the second case that does not satisfy formula (3)

[0145] A. Formula (11) is the second case that does not satisfy Formula (3), that is: the temperature field T of the i-th cell after cooling ex,1,i The temperature is too low, the temperature field T of the i-th cell ex,1,i Lower than the target temperature field T of the i-th cell ex,0,i The degree of error is greater than the set threshold error. In this case, the cooling flow rate should be reduced, so the right side of formula (12) adopts the subtraction method.

[0146] B. Since the formula (11) does not meet the requirements of formula (3) only when the temperature is too low, the temperature is too low, which means it is lower than the target value, that is, the temperature is too low when the cooling flow is too much. Therefore, the formula (12) The minimum mass flow rate among the flow rates corresponding to multiple temperatures in the current temperature field should be selected; since formula (11) indicates that the temperature is too high, higher than the target value, that is, the cooling flow rate is too small, which causes the temperature to be too high, so formula (12) To select the maximum mass flow rate among multiple flow rates corresponding to the current temperature field;

[0147] Step 3: The coolant control unit flow regulating valve controls the opening to release the corresponding coolant flow.

[0148] The specific process is as follows: the flow prediction subunit obtains the coolant flow that ultimately meets the requirements of formula (3) And send it to the active cooling lattice sandwich structure through the coolant control module.

[0149] Step 4. Return to step 1.

[0150] It should be emphasized that the above specific embodiments are merely explanations of the present invention and are not limitations of the present invention. After reading this specification, those skilled in the art may make non-creative modifications to the above embodiments as needed, but as long as they are within the scope of the claims of the present invention, they are protected by patent law.

Claims

1. A high-temperature lattice sandwich structure active cooling dynamic thermal management method, the method is based on a high-temperature lattice sandwich structure active cooling dynamic thermal management system, the system includes an active cooling lattice sandwich structure, a temperature unit, an external substrate outer temperature index setting unit, a solution unit, and a coolant control unit; The solution unit is provided with a temperature field prediction subunit and a flow prediction subunit; the temperature unit is provided with an outer substrate outer side temperature prediction subunit and an inner substrate outer side temperature monitoring subunit; the inner substrate outer side temperature monitoring subunit is arranged on the outer side of the inner substrate of the active cooling lattice sandwich structure, and the outer substrate outer side temperature prediction subunit is obtained by prediction by the temperature field prediction subunit; the coolant control unit is provided with a coolant flow monitoring subunit, a coolant pressure monitoring subunit, a coolant temperature monitoring subunit, a coolant flow control subunit, and a coolant storage subunit; the coolant control unit is arranged at the inlet of the coolant flow channel of the lattice sandwich structure; the outer substrate outer side temperature index setting unit and the solution unit are respectively arranged on a computer; The input end of the active cooling sandwich structure is connected to the coolant storage unit, and the output end is connected to the inner substrate outer temperature monitoring subunit; the input end of the solution unit is respectively connected to the outer substrate outer temperature indicator unit, the inner substrate outer temperature monitoring subunit, the coolant flow monitoring subunit, the coolant pressure monitoring subunit, and the coolant temperature monitoring subunit, and the output end is connected to the coolant flow control subunit; the input end of the coolant control unit is connected to the flow prediction subunit, and the output end is connected to the active cooling sandwich structure; the input ends of the coolant flow monitoring subunit, the coolant pressure monitoring subunit, and the coolant temperature monitoring subunit are respectively connected to the coolant storage subunit, and the output ends are connected to the flow prediction subunit; It is characterized by: The method comprises the following steps: Step 1: Set a dynamic management target based on a high-temperature lattice sandwich structure, set a dynamic thermal management time interval t0, initialize t to t=0, and start timing t. When t=t0, execute step 2. Step 2: The temperature field prediction subunit predicts the temperature field distribution T ex,1 , the flow prediction subunit obtains the coolant flow that ultimately meets the target requirements Step 3: The coolant control unit flow regulating valve controls the opening to release the corresponding coolant flow. Step 4. Return to step 1.

2. The method for active cooling dynamic thermal management of a high-temperature lattice sandwich structure according to claim 1, characterized in that: The setting of step 1 is based on the dynamic management target of the high-temperature lattice sandwich structure, and the dynamic management target is specifically: T ex,0 =(T ex,0,1 ,T ex,0,2 ,…T ex,0,n ) (1) In formula (1), T ex,0 is the known quantity, T ex,0 is the axial distribution of the target service temperature outside the outer substrate, i represents the i-th lattice sandwich structure cell along the axial direction, T ex,0,i is the average temperature of the i-th lattice sandwich structure cell, and n is the total number of lattice sandwich structure cells along the axial direction.

3. The method for active cooling dynamic thermal management of a high-temperature lattice sandwich structure according to claim 1, characterized in that: The temperature field prediction subunit in step 2 predicts the temperature field distribution T ex,1 , the flow prediction subunit obtains the coolant flow that ultimately meets the target requirements The details are as follows: 1) The temperature field prediction subunit obtains the actual temperature T of the inner substrate outer side measured by the inner substrate outer side temperature monitoring subunit w ; T w =(T w,1 ,T w,2 ,…T w,n ) (2) T on the left side of formula (2) w is the axial distribution of the temperature outside the inner substrate, T w is the known quantity measured by the temperature monitoring subunit of the inner substrate and outer substrate; T on the right side of formula (2) w,i is the average temperature of the i-th lattice sandwich structure cell; 2) Temperature field prediction subunit is based on T w and T ex,0 The temperature distribution and the current given coolant flow rate Calculate the predicted temperature distribution T outside the outer substrate at the yth iteration ex,1 ; 3) The traffic prediction subunit contains T ex,1 Formula (3) determines Whether the target requirements are met: in, is the coolant flow rate given by the yth iteration; T ex,1 The temperature of any cell in the lattice sandwich structure is less than or equal to T ex,0 The corresponding temperature in: error is the threshold constant set according to the iteration target; the first sub-formula in formula (3) represents the actual temperature T of any cell in the axial direction of the lattice sandwich structure ex,1,i are all lower than the target temperature T ex,0,i The second sub-formula in formula (3) indicates the target temperature T of a cell in the axial direction of the lattice sandwich structure. ex,0,i With the actual temperature T ex,1,i The difference is less than or equal to the threshold error; 4) Iteration Output flow that meets target requirements The specific steps are as follows: i. When the predicted temperature distribution T ex,1 When formula (3) is satisfied, the set flow rate Output flow ii. When the predicted temperature distribution T ex,1 When formula (3) is not satisfied, the flow prediction subunit calculates the coolant flow for the y+1th iteration And return to process 2) Give the temperature field prediction subunit.

4. The method for active cooling dynamic thermal management of a high-temperature lattice sandwich structure according to claim 3, characterized in that: The temperature field prediction subunit in step 2) is based on T w and T ex,0 The temperature distribution and the current given coolant flow rate Calculate the predicted temperature distribution T on the outside of the outer substrate at the yth iteration ex,1 , as follows: ⑴. Establish the thermal balance equation of the inner substrate: F1=E w-d +E bar-d +E f-d +E d，rad =0 (4) In formula (4), F1 represents the thermal balance equation of the inner substrate, E w-d is the heat conduction heat flow outside the inner substrate; E bar-d is the heat conduction heat flow between the inner base plate and the rod; E f-d is the convective heat flux between the coolant and the inner substrate; E d，rad is the net radiation heat flux inside the inner substrate; E in formula (4) w-d , E bar-d , E f-d and E d,bar All are unknown quantities T d,i , T bar,i , T u,i and the known quantity T w,i , T i Function of T d,i is the inner substrate temperature, T bar,i is the rod temperature, T u,i is the temperature inside the outer substrate, T i is the coolant inlet temperature of the i-th lattice sandwich structure cell, which is calculated from the outlet temperature of the i-1-th lattice sandwich structure cell; ⑵、Establish the thermal balance equation of rod temperature: Where F2 represents the heat balance equation of the rod temperature; the first term on the right side of formula (5) represents the conduction heat flux gradient at the local coordinate x, the second term on the right side of formula (5) represents the convective heat flux at the local coordinate x, T i is the coolant inlet temperature of the i-th lattice sandwich structure cell, and the axial direction of the rod is the x direction of the rod; the conduction heat flux gradient at the local coordinate x = the convective heat flux at the local coordinate x ÷ the cross-sectional area of the rod; since the total radiation heat flux density on the rod surface is small relative to the convective heat flux density, the radiation heat flux E in formula (4) is d，rad Not considered; In formula (5), k s (T bar ) is the thermal conductivity of the lattice material and is the rod temperature T bar，i Function of P bar is the cross-sectional perimeter of the member; A bar is the cross-sectional area of the rod; h ∞，bar is the local convection heat transfer coefficient of the rod; In formula (5), k s , P bar , A bar , h ∞,bar and T i are all known quantities, T bar,i is an unknown quantity; ⑶. Establish the thermal balance equation of the external substrate temperature: F3=E d-u +E f-u +E bar-u =0 (6) Among them, F3 represents the thermal balance equation of the external substrate temperature, E d-u is the net radiation heat flow from the inner side of the inner substrate to the outer substrate; E f-d is the heat flow of convective heat transfer between the coolant and the external substrate; E bar-u is the conduction heat flux between the outer base plate and the rod; E in formula (6) d-u , E f-u , E f-d and E bar-u All are unknown quantities T d,i , T bar,i , T u,i and the known quantity T i function; ⑷、Use the unknown quantity T in formula (4)(5)(6) d,i ,T bar,i ,T u,i The general expression is F j =F j (T d,i ,T bar,i ,T u,i ), due to T in (4)(5)(6) i is a known quantity, so F j is the unknown quantity T d,i , T bar,i , T u,i and the known quantity T i function; The heat fluxes in the above equations (4) and (6) can be generalized to be expressed as E = E (T d,i , T bar,i ,T u,i ,T i ), since the thickness of the outer substrate is generally very small and the material with high thermal conductivity is used, the temperature inside and outside the outer substrate is considered to be the same, that is, T u,i =T ex,1,i ,so, E=E(T d,i , T bar,i ,T ex,1,i ,T i ), and (4) only has T bar,i is an unknown number, so it can be written as F1 = F1(T d,i , T bar,i , T ex,1,i , T i ), F2 = F2(T bar,i , T i ), and F3 = F3(T d,i , T bar,i , T ex,i , T i ), Therefore, formulas (4), (5), and (6) can be generalized as F j =F j (T d,i ,T bar,i ,T ex,1,i ,T i )j∈{1,2,3}; ⑸、Transform the above equation F j Combined, used to establish the solution of the unknown quantity T=(T d,i ,T bar,i ,T ex,1,i ); F(T,T i )=F(T d,i ,T bar,i ,T ex,1,i ,T i )=0 (7) Where F = [F1 F2 F3] T , iteratively solve formula (7) to obtain the unknown quantity of solid temperature field T = (T d,i ,T bar,i ,T ex,1,i ) numerical solution; (6) Calculate the coolant temperature T at the outlet of the i-th cell of the lattice sandwich structure based on the solved unknown quantity T of the solid temperature field i+1 , the coolant temperature balance equation at the inlet and outlet of each cell of the lattice sandwich structure is obtained: Where, formula (8) removes T i+1 are all known quantities, is the given coolant mass flow rate at the yth iteration, C p The specific heat of the coolant is a known quantity, E f-d , E f-u and E f-bar In process (5), by solving T = (T d,i ,T bar,i ,T ex,1,i ) has been obtained and is a known quantity; solving formula (8) can obtain T i+1 Therefore, the method of solving the unknown quantity T of the solid temperature field in the i-th cell of the next lattice sandwich structure (i+1th) can be used in the same way as in the above formulas (4)-(7), and the numerical solutions of T of all lattice sandwich structure cells along the axial direction can be obtained in turn, thereby calculating the predicted temperature distribution T of the outer side of the outer substrate of all cells of the lattice sandwich structure. ex,1 .

5. The method for active cooling dynamic thermal management of a high-temperature lattice sandwich structure according to claim 3, characterized in that: The process of step 2 4) in step ii when the predicted temperature distribution T ex,1 When formula (3) is not satisfied, the flow prediction subunit calculates the coolant flow for the y+1th iteration The details are as follows: ① The first case: For the predicted temperature T that does not satisfy the first sub-formula of formula (3) ex,1,i are all lower than the target temperature T ex,0,i situation, that is: The coolant mass flow rate is: Formula (9) Indicates that there is a temperature T somewhere outside the outer substrate ex，1，i Specific temperature index T ex，0，i High; Formula (10) represents the next coolant mass flow ② The second case: For any location that does not satisfy the second sub-formula of formula (3), the predicted temperature T ex,0,i -T ex,1,i are all greater than the threshold error, that is: Then: The coolant mass flow rate is: Formula (11) represents the index temperature T at any point outside the outer substrate: ex,0,i -Predicted temperature T ex,1,i When the coolant mass flow rate is greater than the threshold value, formula (12) indicates the next coolant mass flow rate.

6. The method for active cooling dynamic thermal management of a high-temperature lattice sandwich structure according to claim 1, characterized in that: The coolant control unit flow regulating valve in step 3 controls the opening to release the corresponding coolant flow The specific process is as follows: the flow prediction subunit obtains the coolant flow that ultimately meets the requirements of formula (3) And send it to the active cooling lattice sandwich structure through the coolant control module.

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