Liquid cooling pipeline and electrical cable layered combined simulation optimization method and system

Abstract

The application discloses a layered combined simulation optimization method and system based on liquid cooling pipelines and electrical cables, and the method comprises the following steps: dividing a parallel liquid cooling pipeline network of a multi-node cold plate into rows according to shared liquid supply side and liquid return side connection nodes, and constructing a simplified pipeline network model by using row equivalent parameters and main flow channels; solving a transient hydraulic equation when a working condition is switched, obtaining time-varying driving pressure differences of each row, and then obtaining time histories of transient flow rates of each branch flow channel; extracting flow rate valley values, valley value occurrence times and recovery time constants, and generating time-varying comprehensive heat dissipation coefficients of cable sections; according to the time-varying comprehensive heat dissipation coefficients, a cable transient thermal equilibrium equation is solved, transient thermal safety margins are evaluated, vulnerable cable sections are identified, and the layout of the vulnerable cable sections is adjusted according to the spatial distribution of flow rate fluctuations. The application can be used for reducing the scale of combined simulation and improving the accuracy of transient thermal safety evaluation of the cables.

Description

Technical Field

[0001] This application relates to the field of simulation technology, specifically to a method and system for hierarchical joint simulation optimization of liquid cooling pipelines and electrical cables. Background Technology

[0002] In high-power-density electronic devices and integrated electrical systems, liquid-cooled pipelines are usually arranged adjacent to electrical cables in a limited space. The heat generated by the operation of the cables is dissipated not only through their own insulation layer and surrounding structure, but also often relies on adjacent liquid-cooled pipelines for removal. For liquid-cooled systems using a multi-node parallel cold plate structure, the flow rate of each branch channel is affected by the pressure distribution of the main channel, the hydraulic resistance of the branches, and fluid inertia. When the equipment load, pump speed, or valve opening changes, the pipeline flow rate does not instantly reach a new steady state, but undergoes a certain transient adjustment process. Some branch channels may experience a short-term flow drop, resulting in a temporary reduction in the heat exchange capacity of the corresponding pipeline section.

[0003] Existing thermal design simulations are mostly based on steady-state flow distribution, calculating cable temperatures under different operating conditions separately. This makes it difficult to reflect the impact of flow troughs and recovery processes on cable heat dissipation during operating condition transitions. Therefore, even if the cable meets temperature requirements under all steady-state operating conditions, temperature overshoot may still occur during transient processes, creating thermal safety hazards that cannot be identified by steady-state analysis. On the other hand, if a high-precision joint transient simulation is performed on the complete liquid-cooled pipe network and all cables, the computational scale is large, the modeling and iterative optimization costs are high, and it is not conducive to quickly locating risky cable segments during the layout design stage. Summary of the Invention

[0004] This application provides a method and system for hierarchical joint simulation optimization of liquid cooling pipelines and electrical cables, in order to at least solve some of the technical problems existing in the related technologies described above.

[0005] According to a first aspect of the embodiments of this application, a layered joint simulation optimization method based on liquid cooling pipelines and electrical cables is provided, including: For a multi-node cold plate parallel liquid cooling network, the branch channels that share the same pair of supply and return liquid connection nodes are divided into the same row, and the equivalent parameters of each row and the main channel are used to form a simplified network model. When switching operating conditions, solve the transient hydraulic equations of the simplified pipeline model to obtain the time-varying driving pressure difference of each row; use the time-varying driving pressure difference as the boundary condition to solve the transient flow distribution equations in each row to obtain the transient flow time history of each branch channel. The flow valley, valley occurrence time, and recovery time constant are extracted from the transient flow time history, and the instantaneous flow time function of each branch channel is constructed accordingly. The instantaneous flow time function is mapped to the time-varying convective heat transfer coefficient of each pipeline segment through the in-pipe convective heat transfer correlation formula, and the time-varying comprehensive heat dissipation coefficient of each cable segment is generated by combining the conduction thermal resistance from the cable to the pipeline. Using the time-varying comprehensive heat dissipation coefficient as the boundary condition, the transient thermal balance equation is solved for each cable segment to obtain the peak temperature and evaluate the transient thermal safety margin, and to identify vulnerable cable segments. The layout of vulnerable cable sections was adjusted according to the spatial distribution of flow fluctuations in each branch channel.

[0006] As an optional approach, the equivalent parameters include equivalent hydraulic resistance and equivalent fluid inertia parameters; the equivalent hydraulic resistance is calculated from the hydraulic resistance of each branch channel within the row according to a parallel relationship, and the equivalent fluid inertia parameters are synthesized from the fluid inertia parameters of each branch channel within the row according to a parallel relationship; the hydraulic resistance of each branch channel is determined by the pipe section length, inner diameter, inner wall roughness, and the density and dynamic viscosity of the coolant, and the fluid inertia parameters of each branch channel are determined by the pipe section length, cross-sectional area, and coolant density.

[0007] As an optional approach, when the equivalent hydraulic resistance of any row changes by more than a preset proportion during the flow redistribution process within the row, the solution of the transient hydraulic equation and the solution of the transient flow distribution equation are iterated alternately: the transient hydraulic equation is solved using the equivalent parameters of the current row to update the time-varying driving pressure difference of each row, the transient flow distribution equation within the row is resolved using the updated time-varying driving pressure difference to update the flow of each branch channel, and the row equivalent parameters are recalculated based on the updated flow, until the flow deviation between two adjacent iterations converges to the allowable range.

[0008] As an optional approach, the flow valley value is the minimum flow value in the transient flow time history of the branch channel; the valley occurrence time is the difference between the time when the minimum flow value occurs and the time when the operating condition is switched; the recovery time constant is obtained by exponentially fitting the flow deviation after the valley occurrence time, and the flow deviation is the difference between the flow at each time and the steady-state flow after the switch.

[0009] As an optional approach, the instantaneous flow time function is a piecewise function: between the time of the operating condition switch and the time of the valley occurrence, the flow changes linearly from the steady-state flow before the switch to the flow valley; after the time of the valley occurrence, the flow recovers from the flow valley to the steady-state flow after the switch in an exponential decay manner, and the time constant of the exponential decay is the recovery time constant.

[0010] As an optional approach, mapping the instantaneous flow rate time function to a time-varying convective heat transfer coefficient includes: using the convective heat transfer coefficient under steady-state conditions before the switch as a reference value, the convective heat transfer coefficient at each moment is calculated and determined based on the reference value, the instantaneous flow rate at that moment, and the steady-state flow rate before the switch.

[0011] As an optional approach, the time-varying comprehensive heat dissipation coefficient is calculated based on conductive thermal resistance and convective heat transfer resistance; the conductive thermal resistance is determined by the distance between the cable segment and adjacent pipes and the thermal conductivity of the filling material; the convective heat transfer resistance is determined by the time-varying convective heat transfer coefficient and the area per unit length of the inner wall of the pipe; when the cable segment is simultaneously affected by heat transfer from multiple pipe segments, the heat dissipation channels of each pipe are considered as parallel paths, and the time-varying comprehensive heat dissipation coefficient is the sum of the heat dissipation coefficients of each path.

[0012] As an optional approach, identifying vulnerable cable segments includes: calculating the cooling dependence of each cable segment and the flow fluctuation sensitivity of adjacent branch channels; the cooling dependence is the proportion of heat dissipation of the cable segment through adjacent pipes to its total heat dissipation; the flow fluctuation sensitivity is calculated by the flow valley value of adjacent branch channels and the steady-state flow rate before switching; when the cooling dependence of the cable segment and the flow fluctuation sensitivity of adjacent branch channels exceed their respective preset thresholds, and the transient thermal safety margin of the cable segment does not meet the requirements, the cable segment is determined to be a vulnerable cable segment.

[0013] As an optional approach, adjusting the layout of vulnerable cable segments according to the spatial distribution of flow fluctuation amplitude in each branch channel includes: arranging each branch channel in the pipeline network according to the flow fluctuation amplitude to construct a spatial distribution map; adjusting vulnerable cable segments to the vicinity of branch channels where the flow fluctuation amplitude meets the requirements, while satisfying cable routing constraints and electrical connection constraints; recalculating the conduction thermal resistance based on the adjusted spatial relationship between the cables and pipelines; and repeatedly performing the generation of time-varying comprehensive heat dissipation coefficient, solving the transient thermal balance equation, and assessing the transient thermal safety margin until the transient thermal safety margin of all cable segments meets the requirements or the feasible layout adjustment space has been exhausted.

[0014] According to a second aspect of the embodiments of this application, a layered joint simulation optimization system based on liquid cooling pipelines and electrical cables is also provided, comprising: The simplified pipeline model construction module is used to divide the branch channels that share the same pair of supply and return liquid connection nodes into the same row for multi-node cold plate parallel liquid cooling pipeline networks. The equivalent parameters of each row and the main channel are used to form a simplified pipeline model. The transient flow rate solution module is used to solve the transient hydraulic equations of the simplified pipeline model when the operating conditions change, and obtain the time-varying driving pressure difference of each row; using the time-varying driving pressure difference as the boundary condition, it solves the transient flow rate distribution equations in each row to obtain the transient flow rate time history of each branch channel. The heat dissipation coefficient generation module is used to extract the flow valley, valley occurrence time and recovery time constant from the transient flow time history, and construct the instantaneous flow time function of each branch channel accordingly; the instantaneous flow time function is mapped to the time-varying convective heat transfer coefficient of each pipeline segment through the in-pipe convective heat transfer correlation formula, and the time-varying comprehensive heat dissipation coefficient of each cable segment is generated by combining the conduction thermal resistance from the cable to the pipeline. The thermal safety assessment module is used to solve the transient thermal balance equation for each cable segment using the time-varying comprehensive heat dissipation coefficient as the boundary condition, obtain the peak temperature and assess the transient thermal safety margin, and identify vulnerable cable segments. The layout adjustment module is used to adjust the layout of vulnerable cable segments according to the spatial distribution of flow fluctuations in each branch channel.

[0015] This application addresses the issue of transient flow downsurge in branch channels during operational switching in multi-node parallel liquid-cooled pipe networks with cold plates. It divides branch channels sharing the same supply and return connection nodes into rows and establishes a simplified pipe network model using row equivalent parameters and the main flow path. This reduces the overall transient hydraulic solution scale while preserving the transient flow change characteristics of each branch channel. Furthermore, it converts the flow valley, valley occurrence time, and recovery time constant into a time-varying comprehensive heat dissipation coefficient for cable segments. This allows the transient thermal analysis of cables to reflect the short-term attenuation of the heat transfer capacity of the liquid-cooled pipe network, thereby identifying transient thermal safety risks that are difficult to detect using steady-state temperature assessment alone. By combining cable cooling dependence, the sensitivity of flow fluctuations in adjacent branch channels, and transient thermal safety margin to identify vulnerable cable segments, and adjusting the layout based on the spatial distribution of flow fluctuation amplitude, it provides a clear basis for the coordinated arrangement of liquid-cooled pipes and electrical cables, improving the thermal safety margin of cables during operational switching and reducing design costs caused by excessive simulation and repeated trial and error.

[0016] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure. Furthermore, no embodiment in this disclosure is required to achieve all the effects described above. Attached Figure Description

[0017] The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure.

[0018] Figure 1 A flowchart of a layered joint simulation optimization method based on liquid cooling pipelines and electrical cables is provided for embodiments of this disclosure.

[0019] Figure 2 This is a schematic diagram illustrating a simplified pipeline network model construction process provided in an embodiment of this disclosure.

[0020] Figure 3A schematic diagram of the process for solving the transient flow distribution in the branch flow channel within a row, provided in an embodiment of this disclosure.

[0021] Figure 4 A schematic diagram of the time-varying comprehensive heat dissipation coefficient generation process provided in this embodiment of the disclosure.

[0022] Figure 5 This is a schematic diagram of the vulnerable cable segment identification process provided in an embodiment of this disclosure.

[0023] Figure 6 This is a schematic block diagram of a layered joint simulation optimization system based on liquid cooling pipelines and electrical cables, provided as an embodiment of this disclosure.

[0024] Figure 7 This is a schematic block diagram of an electronic device provided in an embodiment of the present disclosure. Detailed Implementation

[0025] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0026] According to embodiments of this disclosure, this method is applicable to scenarios where liquid cooling pipelines and electrical cables in electronic devices or systems are physically adjacent to each other. In such systems, multiple cold plate nodes are connected in parallel to the main supply and return channels through their respective branch channels, forming a multi-node parallel liquid cooling pipeline network. Cables are laid along the pipeline route, and their heat dissipation path depends partly or entirely on the convective heat transfer of coolant in adjacent pipelines. When the system switches operating conditions, the flow rate of each branch channel in the pipeline network will transition from one steady state to another. Due to the inertia of the fluid in the pipe and the difference in hydraulic resistance of each branch, the flow rate of some branch channels will be temporarily lower than the smaller of the two steady-state values ​​before and after the switch, resulting in a flow trough. The instantaneous decrease in flow rate causes a simultaneous reduction in the convective heat transfer capacity of adjacent pipeline sections, resulting in a sudden deterioration in the heat dissipation conditions of the adjacent cable section. This leads to an overshoot in the cable temperature that exceeds any steady-state operating temperature. Steady-state thermal simulation only calculates the cable temperature based on the steady-state flow distribution of each operating condition and cannot capture the aforementioned transient temperature overshoot. This method introduces the transient hydraulic response characteristics of the pipeline network into the boundary conditions of cable thermal simulation to identify transient thermal safety hazards missed by steady-state analysis.

[0027] The implementation process of the method described in this application will be described in detail below with reference to specific embodiments. It should be noted that this embodiment is only used to explain this application and is not intended to limit the scope of protection of this application. Conventional adjustments or substitutions of each step by those skilled in the art without departing from the concept of this application should be included in the scope of protection of this application.

[0028] Please see Figure 1 , Figure 1 A flowchart of the layered joint simulation optimization method based on liquid cooling pipelines and electrical cables provided in this disclosure is shown, as follows: Figure 1 As shown, the method includes steps S1-S5: In step S1, for the multi-node cold plate parallel liquid cooling pipe network, the branch channels that share the same pair of supply side and return side connection nodes are divided into the same row, and the equivalent parameters of each row and the main channel are used to form a simplified pipe network model.

[0029] Please see Figure 2 , Figure 2 A simplified pipeline network model construction process provided in this disclosure embodiment is illustrated in the diagram. Figure 2 As shown in box 201, for a multi-node cold plate parallel liquid cooling network, the branch channels that share the same pair of supply side and return side connection nodes are divided into the same row.

[0030] Specifically, a topological model is established based on the physical connections of the liquid-cooled piping network, abstracting the network into a directed graph structure composed of nodes and pipe segments. Nodes include supply inlet nodes, return outlet nodes, connection nodes between branch channels and the main flow channel, and cold plate nodes. Pipe segments include the main supply channel segment, the main return channel segment, and branch channel segments. In this topological model, each pipe segment is assigned hydraulic resistance parameters and fluid inertia parameters. The hydraulic resistance parameter describes the pressure drop characteristics of the pipe segment at a given flow rate, determined by the segment length, inner diameter, inner wall roughness, and the density and dynamic viscosity of the coolant at the current temperature. For laminar flow conditions, the hydraulic resistance of the pipe segment has a linear relationship with the flow rate, while for turbulent flow conditions, it has a non-linear relationship. The fluid inertia parameter describes the pressure difference required for the fluid within the pipe segment to accelerate or decelerate, determined by the segment length, cross-sectional area, and coolant density. Its physical meaning is the ratio of the fluid mass to the cross-sectional area within the pipe segment. This parameter determines the speed of the fluid's response when transitioning from one flow state to another within the pipe segment.

[0031] In the above topology model, all branch channels in the pipeline network are traversed, and branch channels that share the same pair of supply-side connection nodes and return-side connection nodes are grouped into the same row. Since they share connection nodes, the driving pressure difference experienced by each branch channel in the same row is the same at any time, and its flow distribution is determined only by the hydraulic resistance and fluid inertia of each branch channel itself, and is independent of the pipeline network structure outside the row. Based on this, all branch channels in the pipeline network are divided into several rows, and each row constitutes a parallel sub-network.

[0032] Under steady-state conditions, the equivalent hydraulic resistance of each row is calculated by the hydraulic resistance of each branch channel within the row in parallel, that is, the reciprocal of the equivalent hydraulic resistance of the row is equal to the sum of the reciprocals of the hydraulic resistance of each branch channel within the row; under transient conditions, the equivalent fluid inertia parameter of each row is synthesized by the fluid inertia parameter of each branch channel in parallel, that is, the reciprocal of the equivalent fluid inertia parameter of the row is equal to the sum of the reciprocals of the fluid inertia parameter of each branch channel within the row.

[0033] The above-mentioned row structure division separates the pipeline network from two interconnected but approximately independent dynamic systems at the physical level. Specifically, one is the main channel system, which consists of the main channel pipe segments and the equivalent parameters of each row, determining the changes in the total flow and driving pressure difference obtained by each row over time; the other is the parallel branch system within each row, which determines the transient distribution of the total flow of the row among the branch channels within the row. The reason for this separation is that the redistribution of flow among the branch channels within a row does not change the total flow between the inlet and outlet nodes of that row (under the first-order approximation), and therefore has minimal impact on the pressure and flow distribution of the main channel. Decomposing the transient hydraulic response of the pipeline network into two levels in this way can avoid the high computational scale caused by directly solving the entire pipeline network, while preserving the transient details of the flow in each branch channel.

[0034] In box 202, a simplified pipe network model is constructed using the equivalent parameters of each row and the main flow path. Utilizing the row structure partitioning results, each row is replaced by its equivalent hydraulic resistance and equivalent fluid inertia parameters, forming a simplified pipe network model together with the main flow path segments. In this model, the branch structure of the pipe network is folded into several equivalent elements, each corresponding to the overall flow characteristics of a row of parallel branches. The number of degrees of freedom in the model is reduced from the total number of branch channels to the sum of the number of rows and the number of main flow path segments.

[0035] In step S2, the transient hydraulic equation of the simplified pipeline model is solved when the operating conditions are switched to obtain the time-varying driving pressure difference of each row; the transient flow distribution equation in each row is solved using the time-varying driving pressure difference as the boundary condition to obtain the transient flow time history of each branch channel.

[0036] Using the row structure division results, each row is replaced by its equivalent hydraulic resistance and equivalent fluid inertia parameters, and together with the main channel pipe segment, they form a simplified pipe network model. In this model, the branch structure of the pipe network is folded into several equivalent elements, and each equivalent element corresponds to the overall flow characteristics of a row of parallel branches. The number of degrees of freedom of the model is reduced from the total number of branch channels to the sum of the number of rows and the number of main channel pipe segments.

[0037] Specifically, please refer to Figure 3 , Figure 3 A schematic diagram of the transient flow distribution solution process for in-row branch channels provided in an embodiment of this disclosure is shown, as follows: Figure 3 As shown in box 301, the transient hydraulic equations of the simplified pipeline model are solved during the switching of operating conditions to obtain the time-varying driving pressure difference of each row.

[0038] When the operating condition changes, flow conservation equations for each node and momentum equations for each pipe segment are established on a simplified pipeline network model, forming a simultaneous transient hydraulic equation set. The flow conservation equation requires that the total inflow and outflow at each node be equal at any given time. The momentum equation describes the relationship between the acceleration of the fluid in each pipe segment and the pressure difference and frictional pressure drop across the pipe segment. Specifically, the pressure difference across the pipe segment minus the frictional pressure drop across the pipe segment equals the product of the fluid inertial parameter and the rate of change of flow over time. Using the flow and pressure distribution under steady-state conditions before the change as initial conditions, the above equation set is discretized in the time dimension and solved by time-progression to obtain the changes in the supply and return pressures at each row's connecting nodes over time. The difference between the supply and return pressures is the time-varying driving pressure difference for that row.

[0039] In one embodiment, the triggering conditions for operating condition switching include sudden changes in the heat load of a cold plate node causing a change in coolant temperature, which in turn leads to a change in coolant viscosity and a change in the hydraulic resistance of the corresponding branch channel; adjustments in pump speed causing a change in the total supply pressure of the pipeline network; and changes in the opening of pipeline valves causing a sudden change in the hydraulic resistance of a branch channel or a row. These triggering events are all manifested in the simplified pipeline network model as a step or rapid change in the hydraulic resistance parameters of one or more pipe segments at a certain moment. Taking a sudden change in heat load as an example, a sudden increase in the heat load emitted by a cold plate node raises the temperature of the coolant flowing through that cold plate, causing a decrease in coolant viscosity. This reduces the friction coefficient of the corresponding branch channel, thus decreasing the hydraulic resistance. This change is transmitted to the simplified pipeline network model via equivalent parameters, causing a change in the equivalent hydraulic resistance of the corresponding row and triggering a redistribution of the main channel pressure.

[0040] Optionally, when the pipeline length is short and the pressure wave propagation time is much shorter than the characteristic time of the flow response, the fluid compressibility term can be ignored in the momentum equation, and only the fluid inertia term and friction term are retained, simplifying the distributed parameter model into a lumped parameter model to reduce the computational scale; in some embodiments, when the main pipeline section is long and the pump switching rate is fast, the pressure wave propagation term needs to be retained to capture the transient impact of the water hammer effect in the main pipeline on the driving pressure difference of each row.

[0041] In block 302, the transient flow distribution equations within each row are solved using the time-varying driving pressure difference as the boundary condition, and the transient flow time history of each branch channel is obtained.

[0042] Specifically, in the second level, the flow redistribution process of each branch channel within each row is analyzed independently. The time-varying driving pressure difference of the row obtained in the first level is used as the input boundary condition. Combined with the hydraulic resistance parameters and fluid inertia parameters of each branch channel within the row, the transient flow distribution equation of the parallel sub-network within the row is solved.

[0043] In the parallel sub-network within the row, an independent momentum equation is established for each branch channel. This equation includes the following: the pressure difference between the two ends of the branch channel is equal to the driving pressure difference between the inlet and outlet nodes of the row, given by the first-level results, and is a known function of time. This driving pressure difference is consumed in two parts: one part is used to overcome the frictional pressure drop generated by pipe wall friction, which is described by the pipe friction characteristic curve and has a definite functional relationship with the instantaneous flow rate; the other part is used to accelerate the fluid in the pipe, and this acceleration term is equal to the fluid inertial parameter of the branch channel multiplied by the rate of change of the flow rate with respect to time. The sum of the two parts equals the driving pressure difference, thus forming the first-order ordinary differential equation of each branch channel with respect to its flow rate.

[0044] When the hydraulic resistance of a branch flow channel within the row increases due to a change in operating conditions, the flow rate of that branch flow channel tends to decrease, and the driving pressure difference between the inlet and outlet nodes of the row undergoes a transient adjustment, causing the flow rates of other branch flow channels within the row to change accordingly. Due to the differences in fluid inertia among the branch flow channels, the flow rate response speed of branch flow channels with high inertia (such as branch flow channels with long pipe lengths or small cross-sectional areas) is slow, and they cannot quickly follow the rapid changes in driving pressure difference, resulting in a downward surge in their flow rate below the new steady-state value during the transient transition. By simultaneously solving the momentum equations of all branch flow channels within the row, using the steady-state flow rate before the switch as the initial condition, and discretizing the solution in the time dimension, the transient flow rate time history of each branch flow channel within the row is obtained.

[0045] In some embodiments, when the equivalent hydraulic resistance of any row changes by more than a preset proportion during the flow redistribution process within the row, the feedback effect of the flow change within the row on the main flow channel side cannot be ignored, and alternating iterative solutions are required between the two levels. The specific process is as follows: solve the transient hydraulic equation with the equivalent parameters of the current row to update the time-varying driving pressure difference of each row; resolve the transient flow distribution equation within the row with the updated time-varying driving pressure difference to update the flow of each branch channel; then recalculate the equivalent parameters of the row based on the updated flow and substitute them back into the simplified pipeline model, repeating this process until the flow deviation between two adjacent iterations converges to the allowable range. The preset proportion is determined based on the allowable influence of the change in the equivalent hydraulic resistance of the row on the error of the driving pressure difference of the row. The allowable range is that the maximum relative deviation or the maximum absolute deviation of the flow time series of the same branch channel in two adjacent iterations does not exceed the preset convergence error, which is determined by the simulation accuracy required for calculating the peak cable temperature.

[0046] Through the above-mentioned hierarchical decomposition process, the transient flow time history of each branch channel in the pipeline network during the switching of operating conditions is obtained. This history records the complete flow change process of each branch channel from the steady state before the switch to the steady state after the switch.

[0047] In step S3, the flow valley, valley occurrence time, and recovery time constant are extracted from the transient flow time history, and the instantaneous flow time function of each branch channel is constructed accordingly. The instantaneous flow time function is mapped to the time-varying convective heat transfer coefficient of each pipeline segment through the in-pipe convective heat transfer correlation formula, and the time-varying comprehensive heat dissipation coefficient of each cable segment is generated by combining the conduction thermal resistance from the cable to the pipeline.

[0048] Specifically, please refer to Figure 4 , Figure 4 A schematic diagram of the time-varying comprehensive heat dissipation coefficient generation process provided in an embodiment of this disclosure is shown, such as... Figure 4 As shown in box 401, the flow valley, the time of valley occurrence, and the recovery time constant are extracted from the transient flow time history.

[0049] After obtaining the transient flow time history of each branch channel, three characteristic parameters are extracted from it. Specifically, for the first... The typical transient flow time history of a branch flow channel is as follows: after the condition switching is triggered, the flow rate deviates from the steady-state value before the switch, reaches the lowest value after a period of decline, and then gradually recovers and approaches the new steady-state value after the switch. This pattern reflects the competition between fluid inertia and hydraulic resistance. That is, in the initial stage of the switch, the driving pressure difference has changed, but the fluid still maintains the original flow state due to inertia, and the flow rate adjustment lags behind the pressure change. When the flow rate deviation intensifies, the imbalance between hydraulic resistance and driving pressure difference provides a restoring force, pushing the flow rate back to the new steady state.

[0050] Based on this, this embodiment defines three characteristic parameters: flow valley value, etc. This represents the minimum flow rate of this branch channel during the transient process, reflecting the coolant supply capacity at the most unfavorable moment. The lower this value, the more drastic the decrease in heat exchange capacity of this pipe section during the transient process; the time of the valley occurrence... The time difference between the occurrence of this minimum value and the switching time of the operating condition reflects the speed at which the most unfavorable state is reached. The shorter this time, the more drastic the decrease in flow rate, and the shorter the time left for the thermal capacity buffer of adjacent cable segments; recovery time constant. As the flow rate recovers from its trough to a new steady state, the flow rate deviation decays back to its initial deviation. The time required is times the flow rate deviation, where the flow rate deviation is defined as the difference between the flow rate at each moment and the steady-state flow rate after switching. The larger the recovery time constant, the longer it takes for the branch channel to recover from the most unfavorable state to normal operation, and the longer the adjacent cable segment is exposed to poor heat dissipation conditions.

[0051] The flow trough and its occurrence time are directly extracted from the numerical results of the transient flow time history. That is, the flow time series is traversed to find the time point with the minimum flow value, which is the flow trough. The difference between this time point and the time of the switchover is the occurrence time of the trough. The extraction of the recovery time constant requires analysis of the flow recovery process after the occurrence of the trough. Specifically, this includes taking the flow time series after the occurrence of the trough, calculating the flow deviation at each time point, and linearly fitting the relationship between the flow deviation and time in a semi-logarithmic coordinate system. In the semi-logarithmic coordinate system, if the flow deviation decays exponentially with time, the fitting result will be a straight line. The negative reciprocal of the slope of the fitted line is the recovery time constant.

[0052] Optionally, for branch channels whose flow rate is always no less than the smaller of the two steady-state flow rates before and after the switch, and whose transient flow rate fluctuations do not cause deterioration of the heat dissipation conditions of adjacent cables, the above three characteristic parameters are not extracted for such branch channels, and they are not included in the subsequent thermal simulation processing. In some embodiments, when the transient flow rate time history of the branch channel shows oscillating decay characteristics rather than monotonically recovering, the first occurrence of the lowest flow rate value is taken as the flow rate valley value, and the decay characteristic time of the flow rate envelope after the first valley value is taken as the recovery time constant. In other embodiments, when the flow rate time history shows multiple downsurges and the lowest value of the subsequent downsurges is lower than the first downsurge, the global lowest value among all downsurges is taken as the flow rate valley value, and the corresponding time is taken as the valley value occurrence time.

[0053] In box 402, based on the three extracted feature parameters, an instantaneous flow-time function is constructed for each branch channel where the flow rate decreases. The purpose of introducing this approximate function is to transform the discrete numerical simulation results into a continuous analytical expression, which facilitates the subsequent mapping of heat transfer coefficients and the solution of the heat balance equation. At the same time, it compresses the transient response of each branch channel from a complete time series into three scalar parameters, reducing the amount of data transmitted from the pipeline side to the thermal simulation side.

[0054] Specifically, let the first The steady-state flow rate before the branch channel switching is The steady-state flow rate after the switch is Both are obtained through steady-state hydraulic analysis of the two operating conditions before and after the switch; the function adopts a piecewise form: between the moment of operating condition switch and the moment the valley value appears, the flow rate changes from the steady-state flow rate before the switch. Linear change to flow trough After the trough occurs, the flow rate rises from the trough. Restored to steady-state flow after switching using an exponential decay method. The time constant of exponential decay is the recovery time constant. Two segments at the time when the trough value appears The value is continuous at this point; specifically, it can be expressed by the formula: ; in For the first Branch channels at time Traffic, The time is calculated from the moment of switching operating conditions. The dimension of each flow parameter is volumetric flow rate, and the dimension of each time parameter is time. The first segment of this piecewise function approximates the flow rate drop phase with a linear decrease, and the second segment approximates the flow rate recovery phase with an exponential recovery. Optionally, when the decrease phase of the transient flow time history exhibits obvious nonlinear characteristics, the first segment can be replaced with other function forms based on fitting the actual decrease curve, such as a cosine half-wave function.

[0055] In box 403, the instantaneous flow rate time function is mapped to the time-varying convective heat transfer coefficient of each pipe section through the in-pipe convective heat transfer correlation.

[0056] After obtaining the instantaneous flow rate time function of each branch channel, it is mapped to the time-varying convective heat transfer coefficient of the inner wall of the corresponding pipe section. During the forced convective heat transfer of the coolant in the pipe, the relationship between the heat transfer coefficient and the flow rate follows the convective heat transfer correlation in the pipe. Under the condition that the coolant physical parameters change little with temperature, the Nusselt number in the correlation is proportional to the power function of the Reynolds number. The Reynolds number is proportional to the volumetric flow rate when the pipe cross-sectional area is fixed. Therefore, the convective heat transfer coefficient can be expressed as a power function of the volumetric flow rate.

[0057] The convective heat transfer coefficient under steady-state conditions before switching For reference, the first The corresponding pipeline section of each branch flow channel at time The convective heat transfer coefficient is determined according to the following proportional relationship: ; in The power exponent of the Reynolds number in the in-pipe convective heat transfer correlation is determined by the selected in-pipe convective heat transfer correlation; for fully developed turbulent in-pipe convective heat transfer... Values ; The convective heat transfer coefficient under steady-state conditions before the switch is determined by the steady-state flow rate before the switch. Substitute the pipe geometry parameters and coolant properties into the selected in-pipe convection correlation for direct calculation; when the instantaneous flow rate... When it drops to the trough Reduced to a minimum, as traffic recovers The flow rate then rises, thus transmitting the transient fluctuations in flow rate to the description of the heat exchange capacity of the pipeline section.

[0058] For example, according to the first Steady-state flow rate before switching of branch channels The Reynolds number is calculated by taking the pipe section's inner diameter and the density and dynamic viscosity of the coolant at the current temperature. Then, the Reynolds number and Prandtl number of the coolant are substituted into the selected forced convection heat transfer correlation to obtain the Nusselt number. Finally, the convective heat transfer coefficient is calculated from the relationship between the Nusselt number, the coolant's thermal conductivity, and the pipe section's inner diameter. For fully developed turbulent conditions, the Nusselt number and Reynolds number in the above correlations... It is directly proportional to the power of Prandtl number. The power is directly proportional to the power; the specific convective heat transfer correlation can be selected according to the actual situation, and this disclosure does not impose any restrictions.

[0059] The above mapping relationship is based on the quasi-steady-state assumption, which assumes that the convective heat transfer state in the pipe at each moment is the same as the steady-state heat transfer state corresponding to the instantaneous flow rate at that moment. This assumption holds when the characteristic time of the flow rate change is much longer than the flow establishment time in the pipe (i.e., the time required for the fluid in the pipe to flow from the inlet to the fully developed state). In some embodiments, when the flow rate changes extremely rapidly and the pipe is long, a time lag correction for the heat transfer coefficient can be introduced, i.e. The calculation does not use The instantaneous flow rate at any given moment, and adopting The average flow rate within a lag time period preceding a given moment, wherein the lag time period is determined by the ratio of the effective length of the adjacent pipe section to the average flow velocity of the coolant during that time period.

[0060] In box 404, the time-varying comprehensive heat dissipation coefficient of each cable segment is generated by combining the conductive thermal resistance of the cable to the pipe. The heat dissipation path of the cable segment starts from the surface of the cable, passes through the solid conduction and air gap between the cable and the pipe to the outer wall of the pipe, then is conducted through the pipe wall to the inner wall of the pipe, and finally the heat is removed through the convective heat transfer of the coolant inside the pipe. This path involves two main components in series: conductive thermal resistance and convective heat transfer resistance.

[0061] Among them, thermal resistance The thermal resistance is determined by the distance between the cable segment and the adjacent conduit, as well as the thermal conductivity of the filler material, which includes thermal pads, air, and structural adhesive. This value is constant for a given physical layout. Specifically, the thermal resistance per unit length is calculated based on the actual distance between the cable segment and the nearest conduit segment and the thermal conductivity of the intermediate filler material. When there is direct contact between the cable and the conduit and thermally conductive filler material is used, the thermal resistance is relatively low. When there is an air gap between them, the thermal resistance increases significantly because the thermal conductivity of air is much lower than that of solid filler material. Therefore, the distance between the cable and the conduit and the filling method have a significant impact on the overall heat dissipation capacity.

[0062] The conductive thermal resistance of the pipe wall is usually much smaller than the conductive thermal resistance and the convective heat transfer thermal resistance inside the pipe, and can be included in the conductive thermal resistance. The convective heat transfer thermal resistance can be obtained by considering the time-varying convective heat transfer coefficient. Area per unit length of the inner wall of the pipeline This can be expressed by the formula: This is the only thermal resistance that changes over time, and its change is directly caused by the transient fluctuations in the flow rate of the branch channel.

[0063] Combining the above series thermal resistances, we obtain the first... Time-varying overall heat dissipation coefficient of cable segment Heat transfer efficiency (RTE) is defined as the ability of a unit length of cable to transfer heat to the coolant under a unit temperature difference, and can be expressed by the formula: ; in For the first Thermal resistance per unit length of cable to the outer wall of adjacent conduit. For adjacent pipeline sections at time The convective heat transfer coefficient, The overall heat dissipation coefficient is the inner wall area per unit length of adjacent pipe sections. Changes occur as the flow rate in the branch channel decreases to a trough. When the flow rate drops to its lowest level, the overall heat dissipation coefficient also drops to its lowest level, and the heat dissipation conditions for the cable are at their most unfavorable; as the flow rate recovers, the overall heat dissipation coefficient gradually increases.

[0064] In one embodiment, when a cable segment is simultaneously affected by heat exchange from multiple pipe segments, the heat dissipation channels of each pipe are treated as parallel paths. Each parallel path has its own independent conductive thermal resistance and time-varying convective heat transfer thermal resistance, and the time-varying comprehensive heat dissipation coefficient is the sum of the heat dissipation coefficients of each path.

[0065] In step S4, the transient thermal balance equation is solved for each cable segment using the time-varying integrated heat dissipation coefficient as the boundary condition to obtain the peak temperature and evaluate the transient thermal safety margin, and to identify vulnerable cable segments.

[0066] Please see Figure 5 , Figure 5 A schematic diagram of the vulnerable cable segment identification process provided in this disclosure embodiment is shown, such as... Figure 5 As shown in box 501, the transient thermal balance equation is solved for each cable segment using the time-varying integrated heat dissipation coefficient as the boundary condition.

[0067] Specifically, for the first For a cable segment, the heat generated per unit length per unit time is partly stored as heat capacity due to the increased cable temperature, and partly transferred to the coolant through a comprehensive heat dissipation path. The transient heat balance equation can be expressed by the formula: ; in The heat capacity per unit length of cable is determined by the cross-sectional area of ​​the cable, the combined density of the conductor and insulation layer, and the specific heat capacity. For this section of cable at time Temperature; This represents the heat output per unit length of the cable segment. The time-varying comprehensive heat dissipation coefficient; The coolant supply temperature is considered a constant when the duration of the operating condition switch is much shorter than the characteristic time of the supply temperature change; the initial condition is the cable temperature when the heat generation power and heat dissipation power are balanced under steady-state conditions before the switch. Due to steady-state thermal equilibrium conditions Confirmed; when the cable electrical load does not change with the switching of operating conditions, .

[0068] in, The current carrying capacity and resistance per unit length of the cable are used to determine the load. During operating condition switching, if the cable's electrical load does not change with the liquid cooling system's operating conditions, then... ,in It is a constant value; if the electrical load switches synchronously, then It is a known time function determined by the electrical system operating condition switching scheme.

[0069] In some embodiments, when the electrical load switches synchronously with the operating conditions of the liquid cooling system, the heat generation power per unit length is... The time function can take either a step form or a linear transition form; taking a linear transition as an example, let the steady-state heating power before switching be... After switching, the steady-state heating power is The electrical load experiences a transition time from the switching moment. Once the switch is complete, the heat generation power during the transition period will be reduced from... Linear change to After the transition ends, maintain Unchanged, among which and The transition time is determined by the cable current carrying capacity and resistance per unit length before and after the switch, respectively. The load switching scheme is given by the electrical system; when the electrical load switching speed is extremely fast... As it approaches zero, the heat generation power degenerates into a step function.

[0070] From the above formula, it can be concluded that after the operating condition is switched... The heat dissipation term on the right side of the equation decreases as the flow rate decreases. Less than the heat item The temperature change rate was positive, and the cable temperature continued to rise; subsequently, the flow recovered. Rebound, but due to heat capacity The existence of this phenomenon means that temperature changes lag behind changes in the heat dissipation coefficient. That is, when the heat dissipation coefficient has recovered to a level sufficient to balance the heat generation power, the cable temperature is still rising until the temperature rises to the point where the heat dissipation power exceeds the heat generation power, at which point the temperature begins to fall. This lag effect causes the peak temperature to exceed the steady-state operating temperature before and after the switch. The larger the heat capacity, the stronger the lag effect. The larger the recovery time constant, the longer the heat dissipation coefficient trough lasts. Both of these factors together determine the magnitude of the temperature overshoot.

[0071] In one embodiment, a numerical method is used to solve the equation. Specifically, the time interval after the operating condition switch is discretized into multiple steps, and within each step, the equation is solved. The value at the start of this step is taken as the value, and the cable temperature at each moment is calculated step by step using an implicit difference scheme. The time step value should be less than one-tenth of the minimum value of the recovery time constant of all branch channels to ensure that the numerical solution can distinguish the rapid change stage of the heat transfer coefficient. The solution time interval should cover the latest moment corresponding to the preset percentage (e.g., 99%) of the flow rate of all branch channels recovering to the new steady-state flow rate, to ensure that the complete process of the peak temperature occurrence can be captured. Optionally, for cases where there is heat conduction along the axial direction between cable segments, an axial conduction term can be added to the equation. However, in most engineering scenarios, the axial length of the cable is much larger than the radial dimension, and the axial heat conduction is much smaller than the radial heat dissipation. Ignoring this term does not affect the accuracy of the peak temperature assessment.

[0072] In box 502, peak temperatures are acquired and transient thermal safety margins are assessed to identify vulnerable cable segments. Peak temperatures are extracted from the time-domain temperature response of each cable segment. ,Right now The maximum value during the entire transient process is obtained by traversing the temperature time series; the transient thermal safety margin is defined as the difference between the upper limit of the allowable operating temperature of this cable segment and the peak temperature. The upper limit of the allowable operating temperature is determined by the temperature resistance rating of the cable insulation material or the system thermal design specification; when the transient thermal safety margin is positive, it indicates that the temperature of this cable segment is always within the safe range during the switching of operating conditions; when the value is zero or negative, it indicates that there is a risk of transient temperature exceeding the limit, which may not be detected when the assessment is based solely on steady-state temperature.

[0073] Vulnerability analysis was conducted on cable segments with insufficient transient thermal safety margins, specifically based on a comprehensive assessment of two dimensions: cooling dependence and flow fluctuation sensitivity. Cooling dependence characterizes the degree to which a cable segment relies on heat exchange with adjacent pipelines. It is calculated as the proportion of heat dissipated by the cable segment through the convection heat exchange path of adjacent pipelines to its total heat dissipation under steady-state conditions before switching. A higher proportion indicates that the cable segment's temperature is more sensitive to changes in pipeline-side heat exchange conditions. For cable segments with other heat dissipation pathways besides pipeline heat exchange (such as natural convection to air or conduction to adjacent structural components), the cooling dependence is lower than that of cable segments that rely entirely on pipeline heat dissipation.

[0074] Flow fluctuation sensitivity characterizes the amplitude of transient flow fluctuations in adjacent branch channels, and its calculation method can be expressed by the formula: ,in For the first Sensitivity to flow fluctuations in branch channels This represents the lowest flow rate value for that branch channel. This represents the steady-state flow rate before the switch; the larger this value, the more drastic the flow rate drop during the switching process of the branch flow channel, and the more significant the decrease in the heat exchange capacity of the pipeline section.

[0075] When the cooling dependence of a cable segment and the flow fluctuation sensitivity of adjacent branch channels exceed their respective preset thresholds, and the transient thermal safety margin of that cable segment does not meet system requirements, the cable segment is determined to be a vulnerable cable segment. The two thresholds are determined based on the system's temperature margin requirements and reliability level, and different values ​​can be set for different application scenarios; this disclosure does not impose any restrictions. The reason for using a two-dimensional comprehensive judgment is that cable segments with high cooling dependence but small flow fluctuations in adjacent branch channels have limited transient temperature overshoot and generally do not pose a transient safety hazard. Conversely, in cases of large flow fluctuations but low cable dependence on pipeline heat dissipation, the impact of flow fluctuations on cable temperature is also limited. Only when both conditions are met simultaneously does the cable segment exhibit a highly sensitive response to transient flow fluctuations in the pipeline network, becoming a weak link in transient thermal safety.

[0076] In step S5, the layout of vulnerable cable segments is adjusted according to the spatial distribution of flow fluctuation amplitude in each branch channel. For the identified vulnerable cable segments, the layout is adjusted according to the spatial distribution of flow fluctuation amplitude in each branch channel in the pipeline network. The adjustment strategy is based on the fact that there are spatial differences in the flow fluctuation amplitude of different branch channels in the same pipeline network when switching operating conditions. That is, branch channels that are farther away from the disturbance source of the switching operating conditions or branch channels with greater hydraulic inertia usually have smaller flow fluctuation amplitudes.

[0077] Specifically, a spatial distribution map is constructed by arranging each branch channel in the pipeline network from largest to smallest according to the flow fluctuation amplitude (i.e., the aforementioned flow fluctuation sensitivity). The current location of each vulnerable cable segment and the corresponding flow fluctuation amplitude of the branch channel are marked on the map. Under the premise of meeting the cable routing constraints (such as minimum bending radius and routing channel restrictions) and electrical connection constraints (such as the unchanged position of the equipment connected at both ends of the cable), the vulnerable cable segments are adjusted from the area near the branch channel with large flow fluctuation amplitude to the area near the branch channel with flow fluctuation amplitude that meets the requirements.

[0078] When making adjustments, priority should be given to target areas that meet the following conditions: the flow fluctuation sensitivity of the adjacent branch channels of the target area is lower than the allowable range specified by the system, or the heat transfer coefficient of the pipeline section in the area is still sufficient to keep the temperature of the adjacent cables below the allowable upper limit at the time of the flow trough; when there are multiple target areas to choose from, select the option with the smallest increase in cable routing length to avoid introducing additional resistance heating and signal attenuation due to the increase in routing length.

[0079] After the layout adjustment is completed, the thermal resistance of each cable segment is recalculated based on the corrected spatial relationship between the cables and conduits. The entire process of generating the time-varying integrated heat dissipation coefficient, solving the transient thermal balance equation, and assessing the transient thermal safety margin is repeated. If the transient thermal safety margin of all cable segments meets the requirements, the layout adjustment is completed. If there are still cable segments that do not meet the requirements, the next round of layout adjustment is performed. The iteration termination condition is that the transient thermal safety margin of all cable segments meets the requirements, or the feasible layout adjustment space that meets the routing constraints and electrical connection constraints has been exhausted.

[0080] Optionally, when the layout adjustment space is limited and it is impossible to eliminate all transient thermal safety hazards by adjusting the cable position, the information of vulnerable cable segments that fail to meet the requirements and their corresponding branch channels can be output to the pipeline design stage as constraints for pipeline topology optimization or pump control strategy adjustment, thereby reducing the flow fluctuation amplitude from the pipeline side to reduce the transient thermal shock to the cables. In some embodiments, the hydraulic inertia characteristics of the connecting pipe segments between the row and the main flow channel with generally large flow fluctuation amplitude can be changed by adjusting the length or inner diameter of the connecting pipe segments, increasing the equivalent fluid inertia of the row and slowing down its response speed to the pressure fluctuation of the main flow channel, thereby reducing the flow downsurge amplitude of each branch channel within the row; after the pipeline topology is adjusted, the hierarchical decomposition and feature parameter extraction need to be re-executed to update the transient flow response feature parameters of each branch channel, and then the subsequent thermal boundary condition construction and transient evaluation process is repeated until the joint layout scheme meets the transient thermal safety requirements of all cable segments.

[0081] Using the above method, the transient hydraulic response is decomposed into layers by utilizing the row structure characteristics of the pipeline network topology to obtain the transient flow response characteristic parameters of each branch channel. Then, the flow fluctuation information on the pipeline side is transmitted as the time-varying heat dissipation boundary conditions on the cable side through the convection heat transfer correlation and the heat transfer resistance model. Combined with the solution of the transient heat balance equation and the identification of vulnerable cable segments, a transient dimension constraint basis is provided for the joint layout optimization of liquid-cooled pipelines and cables, so that the temperature of each cable segment is within the allowable range during the transient process of operating condition switching in the final layout scheme.

[0082] Please see Figure 6 , Figure 6 This is a structural block diagram of a layered joint simulation optimization system based on liquid cooling pipelines and electrical cables, provided in an embodiment of this application. Figure 6 As shown, the system includes: The simplified pipeline model construction module 601 is used to divide the branch channels that share the same pair of supply and return liquid connection nodes into the same row for multi-node cold plate parallel liquid cooling pipeline networks, and to construct a simplified pipeline model with the equivalent parameters of each row and the main channel. The transient flow rate solving module 602 is used to solve the transient hydraulic equations of the simplified pipeline model when the operating conditions are switched, and obtain the time-varying driving pressure difference of each row; and to solve the transient flow rate distribution equations in each row using the time-varying driving pressure difference as the boundary condition, so as to obtain the transient flow rate time history of each branch channel. The heat dissipation coefficient generation module 603 is used to extract the flow valley, valley occurrence time and recovery time constant from the transient flow time history, and construct the instantaneous flow time function of each branch channel accordingly; the instantaneous flow time function is mapped to the time-varying convective heat transfer coefficient of each pipeline segment through the in-pipe convective heat transfer correlation formula, and the time-varying comprehensive heat dissipation coefficient of each cable segment is generated by combining the conduction thermal resistance from the cable to the pipeline. The thermal safety assessment module 604 is used to solve the transient thermal balance equation for each cable segment with the time-varying comprehensive heat dissipation coefficient as the boundary condition, obtain the peak temperature and assess the transient thermal safety margin, and identify vulnerable cable segments. The layout adjustment module 605 is used to adjust the layout of vulnerable cable segments according to the spatial distribution of the flow fluctuation amplitude of each branch channel.

[0083] Each processing unit and / or module in the embodiments of this application can be implemented by an analog circuit that implements the functions described in the embodiments of this application, or by software that executes the functions described in the embodiments of this application.

[0084] Based on the same inventive concept, this application also provides an electronic device, the method corresponding to which can be the method in the foregoing embodiments, and its problem-solving principle is similar to that method. For example... Figure 7 As shown, Figure 7 This is a schematic block diagram of an electronic device provided in an embodiment of the present disclosure. The device includes: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to perform the methods and / or technical solutions of the foregoing embodiments of the present application.

[0085] In particular, the methods and / or embodiments in this application can be implemented as computer software programs. For example, the embodiments disclosed in this application include a computer program product comprising a computer program carried on a computer-readable medium, the computer program containing program code for performing the methods shown in the flowchart. When the computer program is executed by a processor, it performs the functions defined in the methods of this application.

[0086] Another embodiment of this application provides a storage medium storing computer program instructions thereon, which can be executed by a processor to implement the methods and / or technical solutions of any one or more embodiments of this application.

[0087] In the above embodiments, the descriptions of each embodiment have different focuses. Parts not described in detail in a certain embodiment can be referred to in the relevant descriptions of other embodiments. The above descriptions are merely preferred embodiments of this application and explanations of the technical principles used. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to the technical solutions formed by specific combinations of the above technical features, but should also cover other technical solutions formed by arbitrary combinations of the above technical features or their equivalent features without departing from the inventive concept.

Claims

1. A layered joint simulation optimization method based on liquid-cooled piping and electrical cables, characterized in that, include: For a multi-node cold plate parallel liquid cooling network, the branch channels that share the same pair of supply and return liquid connection nodes are divided into the same row, and the equivalent parameters of each row and the main channel are used to form a simplified network model. When switching operating conditions, solve the transient hydraulic equations of the simplified pipeline model to obtain the time-varying driving pressure difference of each row; use the time-varying driving pressure difference as the boundary condition to solve the transient flow distribution equations in each row to obtain the transient flow time history of each branch channel. The flow valley, valley occurrence time, and recovery time constant are extracted from the transient flow time history, and the instantaneous flow time function of each branch channel is constructed accordingly. The instantaneous flow time function is mapped to the time-varying convective heat transfer coefficient of each pipeline segment through the in-pipe convective heat transfer correlation formula, and the time-varying comprehensive heat dissipation coefficient of each cable segment is generated by combining the conduction thermal resistance from the cable to the pipeline. Using the time-varying comprehensive heat dissipation coefficient as the boundary condition, the transient thermal balance equation is solved for each cable segment to obtain the peak temperature and evaluate the transient thermal safety margin, and to identify vulnerable cable segments. The layout of vulnerable cable sections was adjusted according to the spatial distribution of flow fluctuations in each branch channel.

2. The method according to claim 1, characterized in that, The equivalent parameters include equivalent hydraulic resistance and equivalent fluid inertia parameters; the equivalent hydraulic resistance is calculated from the hydraulic resistance of each branch channel within the row according to the parallel relationship, and the equivalent fluid inertia parameters are synthesized from the fluid inertia parameters of each branch channel within the row according to the parallel relationship; the hydraulic resistance of each branch channel is determined by the pipe section length, inner diameter, inner wall roughness, and the density and dynamic viscosity of the coolant, and the fluid inertia parameters of each branch channel are determined by the pipe section length, cross-sectional area, and coolant density.

3. The method according to claim 1, characterized in that, When the equivalent hydraulic resistance of any row changes by more than a preset proportion during the flow redistribution process within the row, the solution of the transient hydraulic equation and the solution of the transient flow distribution equation are iterated alternately: the transient hydraulic equation is solved with the equivalent parameters of the current row to update the time-varying driving pressure difference of each row, the transient flow distribution equation within the row is resolved with the updated time-varying driving pressure difference to update the flow of each branch channel, and the row equivalent parameters are recalculated based on the updated flow until the flow deviation between two adjacent iterations converges to the allowable range.

4. The method according to claim 1, characterized in that, The flow valley value is the minimum flow value in the transient flow time history of the branch channel; the valley occurrence time is the difference between the time when the minimum flow value occurs and the time when the operating condition is switched; the recovery time constant is obtained by exponentially fitting the flow deviation after the valley occurrence time, and the flow deviation is the difference between the flow at each time and the steady-state flow after the switch.

5. The method according to claim 1, characterized in that, The instantaneous flow time function is a piecewise function: between the time of the operating condition switch and the time of the valley value, the flow rate changes linearly from the steady-state flow rate before the switch to the flow valley value; after the time of the valley value, the flow rate recovers from the flow valley value to the steady-state flow rate after the switch in an exponential decay manner, and the time constant of the exponential decay is the recovery time constant.

6. The method according to claim 1, characterized in that, Mapping the instantaneous flow rate as a time function to a time-varying convective heat transfer coefficient includes: using the convective heat transfer coefficient under steady-state conditions before the switch as a reference value, the convective heat transfer coefficient at each moment is calculated and determined based on the reference value, the instantaneous flow rate at that moment, and the steady-state flow rate before the switch.

7. The method according to claim 1, characterized in that, The time-varying comprehensive heat dissipation coefficient is calculated based on the conductive thermal resistance and the convective heat transfer thermal resistance; the conductive thermal resistance is determined by the distance between the cable segment and the adjacent pipe and the thermal conductivity of the filling material; the convective heat transfer thermal resistance is determined by the time-varying convective heat transfer coefficient and the area per unit length of the inner wall of the pipe; when the cable segment is simultaneously affected by the heat transfer of multiple pipe segments, the heat dissipation channels of each pipe are considered as parallel paths, and the time-varying comprehensive heat dissipation coefficient is the sum of the heat dissipation coefficients of each path.

8. The method according to claim 1, characterized in that, The identification of vulnerable cable segments includes: calculating the cooling dependence of each cable segment and the flow fluctuation sensitivity of adjacent branch channels; the cooling dependence is the proportion of the heat dissipation of the cable segment through adjacent pipes to its total heat dissipation; the flow fluctuation sensitivity is calculated by the flow valley value of adjacent branch channels and the steady-state flow rate before switching; when the cooling dependence of the cable segment and the flow fluctuation sensitivity of adjacent branch channels exceed their respective preset thresholds, and the transient thermal safety margin of the cable segment does not meet the requirements, the cable segment is determined to be a vulnerable cable segment.

9. The method according to claim 1, characterized in that, Adjusting the layout of vulnerable cable segments according to the spatial distribution of flow fluctuation amplitude in each branch channel includes: constructing a spatial distribution map by arranging each branch channel in the pipeline network according to the flow fluctuation amplitude; adjusting vulnerable cable segments to the vicinity of branch channels where the flow fluctuation amplitude meets the requirements, while satisfying cable routing constraints and electrical connection constraints; recalculating the conduction thermal resistance based on the adjusted spatial relationship between the cables and pipelines; and repeatedly performing the generation of time-varying comprehensive heat dissipation coefficient, solving the transient thermal balance equation, and assessing the transient thermal safety margin until the transient thermal safety margin of all cable segments meets the requirements or the feasible layout adjustment space has been exhausted.

10. A hierarchical joint simulation optimization system based on liquid-cooled pipelines and electrical cables, characterized in that, include: The simplified pipeline model construction module is used to divide the branch channels that share the same pair of supply and return liquid connection nodes into the same row for multi-node cold plate parallel liquid cooling pipeline networks. The equivalent parameters of each row and the main channel are used to form a simplified pipeline model. The transient flow rate solution module is used to solve the transient hydraulic equations of the simplified pipeline model when the operating conditions change, and obtain the time-varying driving pressure difference of each row; using the time-varying driving pressure difference as the boundary condition, it solves the transient flow rate distribution equations in each row to obtain the transient flow rate time history of each branch channel. The heat dissipation coefficient generation module is used to extract the flow valley, valley occurrence time and recovery time constant from the transient flow time history, and construct the instantaneous flow time function of each branch channel accordingly; the instantaneous flow time function is mapped to the time-varying convective heat transfer coefficient of each pipeline segment through the in-pipe convective heat transfer correlation formula, and the time-varying comprehensive heat dissipation coefficient of each cable segment is generated by combining the conduction thermal resistance from the cable to the pipeline. The thermal safety assessment module is used to solve the transient thermal balance equation for each cable segment using the time-varying comprehensive heat dissipation coefficient as the boundary condition, obtain the peak temperature and assess the transient thermal safety margin, and identify vulnerable cable segments. The layout adjustment module is used to adjust the layout of vulnerable cable segments according to the spatial distribution of flow fluctuations in each branch channel.

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