Method and device for simulating thermal performance of printed circuit board heat exchanger and medium

Abstract

The invention discloses a thermal performance simulation method and device for a printed circuit board heat exchanger and a medium. The method comprises the steps that a dynamic physical property calling method is established to form a dynamic link library; a three-dimensional distribution parameter model is established according to the structural size of the printed circuit board heat exchanger, and a three-dimensional array C [I] [J] [K] is used for representing all control units of the heat exchanger; establishing a flow direction description matrix of the cold side working medium and the hot side working medium in the printed circuit board heat exchanger control unit; based on the dynamic link library and the flow direction description matrix, respectively establishing control equations of cold and hot side working media of each control unit C (i, j, k); and establishing a simulation iterative algorithm of the printed circuit board heat exchanger to carry out iterative solution on the control equations of the cold and hot side working media of all the control units C (i, j, k), and when a convergence condition is met, ending thermal performance simulation and outputting a simulation result.

Description

Technical Field

[0001] The present invention relates to a method, a device and a medium for simulating the thermal performance of a printed circuit board type heat exchanger based on a three-dimensional distributed parameter model, and relates to the field of energy heat exchangers. Background Art

[0002] Printed circuit board heat exchanger (also called PCHE heat exchanger) is a type of partition wall microchannel heat exchanger. Figure 1 As shown in the figure, it is mainly composed of core, head, connecting pipe and flange. Figure 2 As shown, the core is the main body of the printed circuit board heat exchanger, which consists of multiple layers of heat exchange plates ( Figure 3 ) are alternately stacked and diffusely connected, and the diameter of the heat exchange channel is generally 0.5 to 2 mm. Figure 4 This is a simplified diagram of the structure of a printed circuit board heat exchanger. One fluid enters and exits from the side of the core, and another fluid enters and exits the core directly. The triangular areas at both ends of the core are cross-flow heat exchange, and the middle area is counter-flow heat exchange. Printed circuit board heat exchangers generally have both cross-flow and counter-flow heat exchange processes.

[0003] Printed circuit board heat exchangers have the advantages of compact structure, high pressure resistance, applicable temperature range and high heat transfer efficiency. Under the same heat transfer load, its size is more than 85% smaller than that of traditional shell and tube heat exchangers. It is currently the most compact and efficient type of heat exchanger and is widely used in offshore oil and gas production platforms, supercritical CO2 power generation, floating storage and regasification units (FSRU), floating liquefied natural gas production storage and unloading units (FLNG) and other energy fields.

[0004] Large printed circuit board heat exchangers have high manufacturing costs and large equipment investments. Their thermal performance directly affects the selection of compressors and other power equipment in the process and the overall energy consumption. At the same time, when dealing with low temperature and phase change heat transfer processes, it is very easy to encounter temperature crossovers, medium ice blockages and other faults due to improper design, which can trigger the shutdown of the entire system in severe cases. Therefore, it is necessary to carry out precise structural design and thermal performance simulation of printed circuit board heat exchangers to meet the process requirements for compactness and energy efficiency indicators.

[0005] Research shows that currently, simulations of the thermal performance of heat exchangers mainly use computational fluid dynamics (CFD) software or special software based on empirical correlations. The channel size of a printed circuit board heat exchanger is 1 to 2 orders of magnitude lower than that of a conventional shell and tube heat exchanger. The number of channels under the same flow cross section is usually 10 times that of a conventional shell and tube heat exchanger. 2 ~10 4 times; at the same time, due to the existence of cross-flow and counter-flow heat exchange in the heat exchanger, the temperature and pressure distribution along the width and length of the heat exchanger core are different.

[0006] Therefore, there are two major difficulties in conducting accurate thermal performance simulation of printed circuit board heat exchangers: First, the huge number of channels makes it difficult to use CFD methods to model, the number of grids is large, and the simulation takes a long time, which cannot meet the timeliness requirements of heat exchanger design in engineering; second, the special software based on empirical correlation mostly uses one-dimensional lumped parameter models or two-dimensional node models. The above models simplify the heat exchanger into a single countercurrent heat exchanger, with fast simulation speed but low accuracy, and cannot calculate the cross-flow heat exchange that is common in printed circuit board heat exchangers. Compared with CFD software, the temperature and pressure distribution of the heat exchanger along the width and length directions cannot be obtained. Therefore, in order to reflect the complex flow characteristics of printed circuit board heat exchangers, while taking into account calculation accuracy and efficiency, finding a new thermal performance simulation method is the key. Summary of the invention

[0007] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, in view of the above problems, the purpose of the present invention is to provide a method, device and medium for simulating the thermal performance of a printed circuit board type heat exchanger based on a three-dimensional distributed parameter model, which can obtain the same simulation results as CFD software while taking into account accuracy and efficiency.

[0008] In order to achieve the above-mentioned invention object, the technical solution adopted by the present invention is:

[0009] In a first aspect, the present invention provides a method for simulating the thermal performance of a printed circuit board type heat exchanger, comprising: establishing a dynamic property calling method to form a dynamic link library; establishing a three-dimensional distributed parameter model according to the structural dimensions of the printed circuit board type heat exchanger, and using a three-dimensional array C[I][J][K] to represent all control units of the heat exchanger, wherein each array element C (i,j,k) represents an independent control unit; establishes a flow direction description matrix of the cold and hot side working fluids in the printed circuit board type heat exchanger control unit; based on the dynamic link library and the flow direction description matrix, establishes each control unit C (i,j,k) The control equations of the cold and hot side working fluids; establish the simulation iteration algorithm of the printed circuit board heat exchanger for all control units C (i,j,k) The control equations of the cold and hot side working fluids are iteratively solved. When the convergence conditions are met, the thermal performance simulation ends and the simulation results are output.

[0010] Furthermore, a dynamic property calling method is established to form a dynamic link library, including: through secondary development of Aspen HYSYS software, a property calling method for the built-in property package of Aspen HYSYS is established and a dynamic link library is formed; input and reading of physical property data of different working fluids are realized by real-time calling of the dynamic link library, including inputting the temperature and pressure parameters of the working fluid to solve the enthalpy value, inputting the pressure and enthalpy value of the working fluid to solve the dryness, temperature, density, specific heat capacity, dynamic viscosity, thermal conductivity, etc.

[0011] Furthermore, a three-dimensional distributed parameter model is established according to the structural dimensions of the printed circuit board heat exchanger, and a three-dimensional array C[I][J][K] is used to represent all control units of the heat exchanger, including: completing the establishment of the geometric model of the printed circuit board heat exchanger according to the direct structural parameters of the input printed circuit board heat exchanger; dividing the core of the printed circuit board heat exchanger into K heat exchange units, and a heat exchange unit generally includes a cold side heat exchange plate and a hot side heat exchange plate; dividing each heat exchange unit into I*J control units, each control unit consists of three parts: a cold side channel, a hot side channel and a wall surface, the control units located in the triangular areas at both ends of the core are cross-flow heat exchange, and the control units in the middle area are counter-flow heat exchange; a three-dimensional array C[I][J][K] is used to describe all control units of the heat exchanger, I, J, K represent the number of control units of the heat exchanger core in the x, y, and z directions respectively, and each array element C (i,j,k) Represents an independent control unit in the core. All control units in the three-dimensional array C[I][J][K] together constitute a three-dimensional distributed parameter model of the heat exchanger, where x is the width, y is the length, and z is the height.

[0012] Furthermore, a flow direction description matrix of the cold and hot side working fluids in the printed circuit board type heat exchanger control unit is established, including:

[0013] Use two I*J matrices M cold and M hot Describe the flow direction of the cold and hot side working fluids in their respective heat exchange units, I represents the number of control units along the x direction of the core, and J represents the number of control units along the y direction of the core;

[0014] According to the geometric model, the matrix M cold The element M cold (i,j) is assigned, M cold (i, j) is composed of a three-dimensional vector, representing the flow direction of the medium in the control unit, M cold The value of (i,j) is determined by the following formula:

[0015]

[0016] Among them, (1,0,0), (-1,0,0) represent the cold side working fluid in control unit C (i,j,k) The flow is along the x direction, (0,1,0), (0,-1,0) represents the cold side working fluid in the control unit C (i,j,k) The flow is along the y direction, (0,0,1), (0,0,-1) represents the cold side working fluid in the control unit C (i,j,k) The internal flow is in the z direction;

[0017] Repeat the above process and calculate the matrix M according to the geometric model. hot The element M hot (i,j) is assigned.

[0018] Furthermore, based on the dynamic link library and the flow direction description matrix, each control unit C is established (i,j,k) The control equations of the cold and hot side working fluids include:

[0019] Establish the energy equation describing the energy transfer between the cold and hot sides:

[0020] Energy Conservation Equation: Q (i,j,k) =m (i,j,k) ·(h out,(i,j,k) -h in,(i,j,k) );

[0021] Heat Transfer Equation: Q (i,j,k) =E (i,j,k) A (i,j,k) ΔT (i,j,k) ;

[0022] (i',j',k')=(i,j,k)+M(i,j);

[0023] h in,(i',j',k') =h out,(i,j,k) ;

[0024] Where Q is the heat transfer, W; m is the mass flow rate, kg / s; h is the mass specific enthalpy, J / kg; ΔT is the logarithmic mean temperature difference of the control unit, °C; E is the total heat transfer coefficient of the control unit, W / (m 2 ·℃); A represents the effective heat exchange area of ​​the control unit, m 2 ; The subscripts in and out represent the inlet and outlet of the control unit respectively; i, j, k represent the control unit C (i,j,k) The position numbers in the three-dimensional array C[I][J][K], i', j', k' represent the position numbers of the control unit C (i,j,k) The position number of the next control unit connected to the outlet, M(i,j) is the matrix element. For the cold side working fluid, M(i,j) is from the matrix M cold For the hot side working fluid, M(i,j) is taken from the matrix M hot Take the value in

[0025] The momentum equation describing the momentum transfer of the working fluid on the cold and hot sides is established:

[0026] p out,(i,j,k) =p in,(i,j,k) -Δp (i,j,k) ;

[0027] (i',j',k')=(i,j,k)+M(i,j);

[0028] p in,(i',j',k') = p out,(i,j,k) ;

[0029] Among them, p represents pressure, kPa; Δp represents pressure drop, kPa.

[0030] Furthermore, a simulation iteration algorithm for the printed circuit board heat exchanger is established to iteratively solve the control equations of all control units C (i,j,k) When the convergence condition is met, the thermal performance simulation ends and the results are output, including:

[0031] S1. Initialize all control units in C[I][J][K];

[0032] S2. According to the flow direction description matrices M hot 、M cold of the cold and hot side flow paths, traverse all control units C (i,j,k) in the heat exchanger. The traversal process is the process of solving the control equations of each control unit. The specific process is as follows:

[0033] S21. Set the control unit numbers as i = 1, j = 1, k = 1;

[0034] S22. Solve the energy equation of the current control unit C (i,j,k) , and at the same time, according to the value of M(i,j) in the flow direction description matrix, transfer the outlet enthalpy value of C (i,j,k) to the downstream control unit C (i’,j’,k’) ; when i < I, then i = i + 1 and continue the loop iteration. Traverse all control units in the width direction of the heat exchanger in turn according to the above method; when j < J, set i = 1, j = j + 1 and continue the loop iteration to complete the traversal of all control units in the length direction of the heat exchanger; when k < K, set i = 1, j = 1, k = k + 1 and continue the loop iteration to complete the traversal of all control units in the height direction of the heat exchanger;

[0035] S23. After solving the energy equations of all control units, start solving the momentum equation, and set the control unit numbers as i = 1, j = 1, k = 1;

[0036] S24. Solve the momentum equation of the current control unit C (i,j,k) , and at the same time, according to the value of M(i,j) in the flow direction description matrix, transfer the outlet pressure of C (i,j,k) to the downstream control unit C (i’,j’,k’); When i < I, then i = i + 1, and traverse all the control units in the width direction of the heat exchanger in sequence according to the above method; when j < J, set i = 1, j = j + 1, and complete the traversal of all the control units in the length direction of the heat exchanger; when k < K, set i = 1, j = 1, k = k + 1, and complete the traversal of all the control units in the height direction of the heat exchanger;

[0037] S25. Complete all the control units C in C[I][J][K] (i,j,k) After solving the energy equation and the momentum equation, convergence determination is carried out. When the convergence condition is met, the iteration is completed and the simulation results are output; when the iteration convergence condition is not met, then repeat steps S21 - S24 until the iteration convergence condition is met.

[0038] Furthermore, the algorithm process for solving the energy equation of the control unit in S22 is as follows:

[0039] S221. Obtain the inlet process parameters of this control unit C (i,j,k) ;

[0040] S222. Solve the maximum heat transfer amount Q according to the inlet process parameters of the control unit C (i,j,k) , and set the initial value of the minimum heat transfer amount Q max to be 0; min ;

[0041] S223. Obtain the physical property parameters of the working fluid by calling the dynamic link library, select the corresponding heat transfer correlation according to the working fluid type and process parameters, and calculate the total heat transfer coefficient E;

[0042] S224. Set the initial value of the heat transfer amount Q = (Q min + Q max ) / 2, solve the outlet parameters of the cold and hot sides of the control unit respectively according to the energy conservation equation, and obtain the logarithmic mean temperature difference ΔT1 of the control unit = (Δt max - Δt min ) / ln(Δt max / Δt min ); Δt max , Δt min are respectively the maximum and minimum values of the temperature differences at the two end faces of the control unit;

[0043] S225. Solve and obtain the logarithmic mean temperature difference ΔT2 of the control unit according to the heat transfer equation = Q / EA;

[0044] S226. Judge whether the deviation value between ΔT1 and ΔT2 meets the convergence condition. If it meets, the iteration terminates, and update the outlet enthalpy values of the cold and hot side working fluids of the control unit C (i,j,k) ;

[0045] S227, if the convergence condition is not met, then determine the size of ΔT1 and ΔT2, and when ΔT1>ΔT2, assign Q to Q min , repeat steps S224-S225; when ΔT1<ΔT2, assign Q to Q max , repeat steps S224-S225; until the iteration meets the convergence condition.

[0046] Furthermore, the process of solving the momentum equation of the control unit in S24 is:

[0047] S241, obtain control unit C (i,j,k) The input parameters of

[0048] S242, obtaining the physical property parameters of the working fluid by calling the dynamic link library, selecting a suitable flow correlation equation according to the working fluid type and process parameters, and calculating the pressure drop Δp of the working fluid on the cold and hot sides respectively;

[0049] S243, update control unit C (i,j,k) The outlet pressure of the working fluid on the cold and hot sides.

[0050] In a second aspect, the present invention also provides an electronic device, characterized in that it comprises: at least one processor; and a memory communicatively connected to the processor; wherein the memory stores instructions executable by the processor, and the instructions are executed by the processor so that the processor can execute any one of the methods described.

[0051] In a third aspect, the present invention further provides a computer-readable storage medium storing one or more programs, wherein the one or more programs include computer instructions, and the computer instructions are used to enable a computer to execute any one of the methods described.

[0052] The present invention adopts the above technical solution, and has the following characteristics:

[0053] 1. The present invention adopts a dynamic link method to call the built-in physical property package of Aspen HYSYS software in real time to directly obtain physical property data. On the one hand, there is no need to establish separate physical property databases for different working fluids, which reduces the workload and improves the simulation efficiency; on the other hand, it can avoid the cumulative error caused by post-processing such as difference calculation of physical property data, and the physical property calculation accuracy is high.

[0054] 2. The present invention adopts a modeling method based on a three-dimensional distributed parameter model to discretize the printed circuit board heat exchanger into a three-dimensional array. By dividing the control unit and establishing a flow path description method based on a flow direction description matrix, it can truly reflect the actual flow state and heat transfer characteristics of the working fluid in the heat exchanger. Compared with the existing one-dimensional, two-dimensional and other simplified countercurrent models, it can describe cross flow and more complex flow forms.

[0055] 3. The present invention establishes a performance simulation method based on a three-dimensional distributed parameter model. Compared with the existing lumped parameter model and sub-node model, on the one hand, it can not only calculate countercurrent heat transfer, but also calculate the heat transfer process under cross flow and mixed flow; on the other hand, it can obtain the same three-dimensional temperature and pressure distribution cloud map of the heat exchanger as the CFD software, and the calculation time is greatly improved compared with the CFD software.

[0056] In summary, the present invention can be widely used in the thermal performance simulation of printed circuit board type heat exchangers. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Throughout the accompanying drawings, the same reference numerals are used to represent the same components. In the accompanying drawings:

[0058] Figure 1 is a schematic diagram of a conventional printed circuit board type heat exchanger;

[0059] Figure 2 The core of the existing printed circuit board type heat exchanger;

[0060] Figure 3 A heat exchange plate for an existing printed circuit board type heat exchanger;

[0061] Figure 4 It is a simplified structural diagram of an existing printed circuit board type heat exchanger;

[0062] Figure 5 A schematic diagram of a method for simulating the performance of a printed circuit board type heat exchanger according to an embodiment of the present invention;

[0063] Figure 6 A schematic diagram of a heat exchange unit of a printed circuit board type heat exchanger according to an embodiment of the present invention;

[0064] Figure 7 A schematic diagram of the discretization of the core of a printed circuit board type heat exchanger according to an embodiment of the present invention;

[0065] Figure 8 It is a flow chart of an iterative algorithm for performance simulation of a printed circuit board type heat exchanger according to an embodiment of the present invention;

[0066] Fig. 9 A heat transfer calculation flow chart of a control unit of a printed circuit board type heat exchanger according to an embodiment of the present invention;

[0067] Fig.10 A flow chart of pressure drop calculation of a control unit of a printed circuit board type heat exchanger according to an embodiment of the present invention;

[0068] Fig.11 It is a schematic diagram of the Aspen HYSYS built-in property package calling principle of an embodiment of the present invention;

[0069] Fig.12 A temperature cloud diagram of a hot side heat exchange plate of a printed circuit board type heat exchanger according to an embodiment of the present invention;

[0070] Fig.13 A temperature cloud diagram of a cold-side heat exchange plate of a printed circuit board type heat exchanger according to an embodiment of the present invention;

[0071] Fig.14 A pressure cloud diagram of a heat exchange plate on the hot side of a printed circuit board type heat exchanger according to an embodiment of the present invention;

[0072] Fig.15 A pressure cloud diagram of a cold-side heat exchange plate of a printed circuit board type heat exchanger according to an embodiment of the present invention;

[0073] Fig.16 A three-dimensional pressure cloud diagram of the cold side of a printed circuit board type heat exchanger according to an embodiment of the present invention;

[0074] Fig.17 FIG. 4 is a structural diagram of an electronic device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0075] It should be understood that the terms used herein are only for the purpose of describing specific example embodiments and are not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms "one", "an" and "said" as used herein may also be meant to include plural forms. The terms "include", "comprise", "contain", and "have" are inclusive, and therefore specify the existence of stated features, steps, operations, elements and / or parts, but do not exclude the existence or addition of one or more other features, steps, operations, elements, parts, and / or combinations thereof. The method steps, processes, and operations described herein are not interpreted as necessarily requiring them to be performed in the specific order described or illustrated, unless the execution order is clearly indicated. It should also be understood that additional or alternative steps may be used.

[0076] The existing lumped parameter model and node model cannot calculate the cross-flow heat transfer in the printed circuit board heat exchanger, and cannot obtain the three-dimensional temperature and pressure distribution of the heat exchanger. The method, device and medium for simulating the thermal performance of a printed circuit board heat exchanger based on a three-dimensional distributed parameter model provided by the present invention include a three-dimensional array representation method for a printed circuit board heat exchanger, a three-dimensional flow description method for a printed circuit board heat exchanger based on a flow direction description matrix, and a traversal algorithm for a control unit based on a three-dimensional array model, which can carry out thermal performance calculations under counterflow, crossflow and other complex flow forms; the fast iteration algorithm for the energy equation of the control unit based on the dichotomy method can achieve rapid convergence of the heat transfer calculation of the control unit without introducing the wall temperature. Therefore, the performance simulation method based on the three-dimensional distributed parameter model established by the present invention can not only calculate counterflow heat transfer, but also calculate the heat transfer process under crossflow and mixed flow.

[0077] The exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0078] Embodiment 1: Figure 5 As shown, the thermal performance simulation method of a printed circuit board type heat exchanger provided in this embodiment includes:

[0079] S1. In the process of thermal performance simulation of heat exchanger, it is necessary to calculate the physical properties of heat exchange medium thousands of times. In order to ensure the accuracy and efficiency of the physical property calculation results, a dynamic physical property calling method for Aspen HYSYS built-in physical property package is first established to form a dynamic link library.

[0080] In this embodiment, through secondary development of Aspen HYSYS software, a physical property calling method for the built-in physical property package of Aspen HYSYS is established and a dynamic link library is formed. The input and reading of physical property data of different working fluids are realized by calling the dynamic link library in real time. For example, the temperature and pressure parameters of the working fluid are input to solve the enthalpy value, and the pressure and enthalpy value of the logistics are input to solve the dryness, temperature, density, specific heat capacity, dynamic viscosity, thermal conductivity, etc.

[0081] S2. A three-dimensional distributed parameter model is established according to the structural dimensions of the printed circuit board type heat exchanger and represented by a three-dimensional array.

[0082] In this embodiment, a three-dimensional distributed parameter model is established according to the structural dimensions of the printed circuit board type heat exchanger and is represented by a three-dimensional array, including:

[0083] S21. Establishment of the geometric model of the printed circuit board type heat exchanger is completed according to the direct structural parameters of the printed circuit board type heat exchanger input by the user. The direct structural parameters include the structural dimensions of the heat exchange plates on the cold and hot sides, the core dimensions, the flow mode of the heat exchange channel, the channel radius, the channel spacing, etc. The indirect structural parameters such as the number of heat exchange plates, the number of single-plate heat exchange channels, the total number of heat exchange channels, the total heat exchange area, etc. can be calculated through the above parameters. The above structural parameters together constitute the geometric model of the heat exchanger.

[0084] S22. Divide the core of the printed circuit board type heat exchanger into K heat exchange units, where one heat exchange unit generally includes a cold side heat exchange plate and a hot side heat exchange plate.

[0085] S23, such as Figure 6 As shown, each heat exchange unit is divided into I*J control units. Each control unit consists of three parts: a cold side channel, a hot side channel and a wall. The control units located in the triangular areas at both ends of the core are cross-flow heat exchangers, and the control units in the middle area are counter-flow heat exchangers.

[0086] S24, such as Figure 7 As shown in the figure, a three-dimensional array C[I][J][K] is used to describe all the control units of the heat exchanger. I, J, and K represent the number of control units in the x (width), y (length), and z (height) directions of the heat exchanger core, respectively. Each array element C (i,j,k) Represents an independent control unit in the core. All control units in the three-dimensional array C[I][J][K] together constitute the three-dimensional distributed parameter model of the heat exchanger.

[0087] S3. Establish a flow direction description matrix of the cold and hot side working fluids in the printed circuit board type heat exchanger control unit.

[0088] In this embodiment, a flow path description method based on a flow direction description matrix is ​​used to obtain a flow direction description matrix, including:

[0089] S31, using two I*J matrices M cold and M hot They respectively describe the flow directions of the cold and hot side working fluids in their respective heat exchange units. I represents the number of control units along the x direction of the core, and J represents the number of control units along the y direction of the core.

[0090] S32, according to the geometric model, the matrix M cold The element M cold (i,j) is assigned, M cold The value of (i, j) is composed of a three-dimensional vector, representing the flow direction of the medium in the control unit, M cold The value of (i,j) is determined by the following formula:

[0091]

[0092] Among them, (1,0,0), (-1,0,0) represent the cold side working fluid in control unit C (i,j,k) The flow is along the x direction, (0,1,0), (0,-1,0) represents the cold side working fluid in the control unit C (i,j,k) The flow is along the y direction, (0,0,1), (0,0,-1) represents the cold side working fluid in the control unit C (i,j,k) The flow is in the z direction.

[0093] S33, repeat step S32, according to the geometric model for the matrix M hot The element M hot (i,j) is assigned.

[0094] S4, based on the three-dimensional distributed parameter model and dynamic link library of the heat exchanger, establish control unit C (i,j,k) The control equations of the cold and hot side working fluids include the mass equation, energy equation and momentum equation of the cold and hot side working fluids.

[0095] In this embodiment, establishing the control equation of the control unit includes:

[0096] S41. Establish the mass equation describing the mass transfer of the working fluid on the cold and hot sides:

[0097] m out,(i,j,k) =m in,(i,j,k)

[0098] (i',j',k')=(i,j,k)+M(i,j)

[0099] m in,(i',j',k') =m out,(i,j,k)

[0100] Where m is the mass flow rate, kg / s; the subscripts in and out represent the inlet and outlet of the control unit respectively, and i, j, and k represent the control unit C. (i,j,k) The position numbers in the three-dimensional array C[I][J][K], i', j', k' represent the position numbers of the control unit C (i,j,k) The position number of the next control unit connected to the outlet, M(i,j) is the matrix element. For the cold side working fluid, M(i,j) is from the matrix M cold For the hot side working fluid, M(i,j) is taken from the matrix M hot Take the value from.

[0101] S42. Establish the energy equation describing the energy transfer between the cold and hot side working fluids:

[0102] Energy Conservation Equation: Q (i,j,k) =m (i,j,k) ·(hout,(i,j,k) -h in,(i,j,k) )

[0103] Heat Transfer Equation: Q (i,j,k) =E (i,j,k) A (i,j,k) ΔT (i,j,k)

[0104] (i',j',k')=(i,j,k)+M(i,j)

[0105] h in,(i',j',k') =h out,(i,j,k)

[0106] Where Q represents the heat transfer, W; h represents the mass specific enthalpy, J / kg; ΔT represents the logarithmic mean temperature difference of the control unit, °C; E represents the total heat transfer coefficient of the control unit, W / (m 2 ·℃); A represents the effective heat exchange area of ​​the control unit, m 2 .

[0107] S43. Establish the momentum equation describing the momentum transfer of the working fluid on the cold and hot sides:

[0108] p out,(i,j,k) =p in,(i,j,k) -Δp (i,j,k)

[0109] (i',j',k')=(i,j,k)+M(i,j)

[0110] p in,(i',j',k') =p out,(i,j,k)

[0111] Where, p represents pressure, kPa; Δp represents pressure drop, kPa;

[0112] S5. Establish the simulation iteration algorithm of printed circuit board heat exchanger for all control units C (i,j,k) The control equations are solved, and the simulation iteration algorithm includes the traversal iteration algorithm of the control unit and the flow and heat transfer iteration algorithm within the control unit.

[0113] In this embodiment, Figure 8 The simulation iteration algorithm for establishing a printed circuit board heat exchanger is shown, including:

[0114] S51. Complete the initialization of all control units in C[I][J][K] created in the above steps, including the initialization of structural parameters and process parameters. The structural parameters include the structural dimensions, heat exchange area, wall thermal conductivity, etc. of the cold and hot side channels of each control unit; the process parameters include the inlet temperature, pressure, enthalpy, flow rate and medium composition of each control unit.

[0115] S52. Describe matrix M according to the flow directions of the cold and hot side flow paths hot , M cold Realize the traversal of all control units C (i,j,k) in the heat exchanger. The traversal process is the process of solving the control equations of each control unit. The specific process is as follows:

[0116] S521. Set the control unit numbers as i = 1, j = 1, k = 1;

[0117] S522. Solve the energy equation of the current control unit C (i,j,k) . At the same time, according to the value of M(i, j) in the flow direction description matrix, transfer the outlet enthalpy value of C (i,j,k) to the downstream control unit C (i’,j’,k’) . When i < I, then i = i + 1 and continue the loop iteration. Traverse all control units in the width direction of the heat exchanger in turn according to the above method; when j < J, set i = 1, j = j + 1 and continue the loop iteration to complete the traversal of all control units in the length direction of the heat exchanger; when k < K, set i = 1, j = 1, k = k + 1 and continue the loop iteration to complete the solution of the energy equations of all control units in the height direction of the heat exchanger.

[0118] S523. After completing the solution of the energy equations of all control units, start the solution of the momentum equations. Set the control unit numbers as i = 1, j = 1, k = 1;

[0119] S524. Solve the momentum equation of the current control unit C (i,j,k) . At the same time, according to the value of M(i, j) in the flow direction description matrix, transfer the outlet pressure of C (i,j,k) to the downstream control unit C (i’,j’,k’) . When i < I, then i = i + 1 and traverse all control units in the width direction of the heat exchanger in turn according to the above method; when j < J, set i = 1, j = j + 1 to complete the traversal of all control units in the length direction of the heat exchanger; when k < K, set i = 1, j = 1, k = k + 1 to complete the solution of the momentum equations of all control units in the height direction of the heat exchanger.

[0120] S525. After completing the solution of the energy equations and momentum equations of all control units C (i,j,k) in C[I][J][K], perform convergence determination. When the convergence condition is met, the iteration is completed and the simulation results are output; when the iteration convergence condition is not met, repeat steps S521 - S524 until the iteration convergence condition is met.

[0121] In this embodiment, when the iteration meets the convergence condition, the thermal performance simulation results are output. The convergence criterion is as follows:

[0122]

[0123] Where T represents temperature; the superscript τ represents the current iteration, and τ-1 represents the previous iteration; the subscript hot represents the hot side; cold represents the cold side; out represents the heat exchanger outlet; and δ is 0.01.

[0124] In this embodiment, Fig. 9 As shown, the algorithm for solving the energy equation of the control unit in S522 is as follows:

[0125] S5221, obtain the control unit C (i,j,k) The inlet process parameters;

[0126] S5222, according to control unit C (i,j,k) The maximum heat transfer Q is obtained by using the inlet process parameters max , set the minimum heat transfer Q min The initial value of is 0;

[0127] S5223, obtaining the physical property parameters of the working fluid by calling the dynamic link library, selecting the corresponding heat transfer correlation equation according to the working fluid type and process parameters, and calculating the total heat transfer coefficient E;

[0128] S5224, set the initial value of heat exchange Q = (Q min +Q max ) / 2, and solve the outlet parameters of the cold and hot sides of the control unit according to the energy conservation equation, and obtain the logarithmic mean temperature difference of the control unit ΔT1=(Δt max -Δt min ) / ln(Δt max / Δt min );Δt max , Δt min They are the maximum and minimum values ​​of the temperature difference between the two end surfaces of the control unit respectively;

[0129] S5225, solving the heat transfer equation to obtain the logarithmic mean temperature difference of the control unit ΔT2 = Q / EA;

[0130] S5226, determine whether the deviation values ​​of ΔT1 and ΔT2 meet the convergence condition. If so, the iteration is terminated and the control unit C is updated. (i,j,k) The outlet enthalpy value;

[0131] S5227. If the convergence condition is not met, determine the size of ΔT1 and ΔT2. When ΔT1>ΔT2, assign Q to Q. min , repeat steps S5224-S5225; when ΔT1<ΔT2, assign Q to Q max , repeat steps S5224-S5225; until the iteration meets the convergence condition.

[0132] In this embodiment, Fig.10 As shown, the process of solving the momentum equation of the control unit in S524 is:

[0133] S5241, obtain control unit C (i,j,k) The input parameters of

[0134] S5242, obtaining the physical property parameters of the working fluid by calling the dynamic link library, selecting a suitable flow correlation equation according to the working fluid type and process parameters, and calculating the pressure drop Δp of the working fluid on the cold and hot sides respectively;

[0135] S5243, update control unit C (i,j,k) The outlet pressure of the working fluid on the cold and hot sides.

[0136] The application of the method for simulating thermal performance of a printed circuit board type heat exchanger based on a three-dimensional distributed parameter model of the present invention is described in detail below through specific embodiments.

[0137] This embodiment is described by taking the printed circuit board type compressor aftercooler WC-2701C used in the dry gas transmission system of a certain offshore gas field in China as an example, but it is not limited to this. The method is also applicable to other occasions, such as the thermal performance simulation of the printed circuit board type regenerator for supercritical CO2 power generation system and the printed circuit board type LNG main vaporizer for floating storage and regasification unit. The process data of the compressor aftercooler are shown in Table 1:

[0138] Table 1: Process data of compressor aftercooler WC-2701C

[0139]

[0140]

[0141] Research shows that when modeling and calculating the three-dimensional distributed parameter model of a printed circuit board heat exchanger, the following reasonable assumptions need to be made: (1) the heat exchanger is in a stable operating condition and the working fluid is in a state of thermal equilibrium; (2) the working fluid is evenly distributed in the heat exchanger; (3) the heat conduction in the x and y directions of the heat exchanger plate is ignored;

[0142] Based on the above assumptions, the thermal performance simulation method of a printed circuit board type heat exchanger based on a three-dimensional distributed parameter model proposed in this embodiment includes the following steps:

[0143] Step 1: Fig.11 As shown in the figure, a physical property calling method for the Aspen HYSYS built-in physical property package is established to form a dynamic link library, including:

[0144] (1) Open Aspen HYSYS software, set the working fluid components, select the physical property package, create a new heat exchanger model, and name the heat exchanger WC-2701C; input the inlet parameters of the heat exchanger under working condition 1: including the inlet components, temperature, pressure and flow rate on the natural gas side, and the inlet components, temperature, pressure and flow rate on the seawater side; save the file as CASE-1.hsc;

[0145] (2) Repeat the above steps to build the heat exchanger model for working condition 2 and save the file as CASE-2.hsc;

[0146] (3) Through the secondary development of Aspen HYSYS, the dynamic link file Prop.dll is generated and the interface function is written to input and read the physical property parameters of the specified working fluid in the specified hsc format file, mainly including the temperature and pressure parameters of the input logistics to solve the enthalpy value; the pressure and enthalpy values ​​of the input logistics are used to solve the dryness, temperature, density, specific heat capacity, dynamic viscosity, thermal conductivity, etc.;

[0147] (4) When performing performance simulation calculations on WC-2701C, the physical property parameters of the working fluid in WC-2701C in the CASE-1.hsc or CASE-2.hsc files are directly input and read by calling the Prop.dll file in real time. There is no need to establish a separate physical property database for WC-2701C, which reduces the workload. At the same time, the physical property data is directly read without post-processing, avoiding cumulative errors and improving the accuracy of simulation calculations.

[0148] Step 2: Establish a three-dimensional distributed parameter model of the compressor aftercooler WC-2701C, including:

[0149] (1) Input the structural parameters of WC-2701C into the thermal performance simulation program to establish a three-dimensional distributed parameter model of the heat exchanger. The structural parameters of WC-2701C are shown in Table 2:

[0150] Table 2: Original structural parameters of compressor aftercooler WC-2701C

[0151]

[0152] (2) More structural information of the heat exchanger obtained based on the above parameters is shown in Table 3:

[0153] Table 3: Detailed structural parameters of compressor aftercooler WC-2701C

[0154]

[0155] (3) WC-2701C is divided into 260 heat exchange units, and each heat exchange unit is further divided into 8*16 control units. The three-dimensional array C[8]

[16]

[260] is used to describe all the control units of WC-2701C. The entire heat exchanger has a total of 33,280 control units.

[0156] Step 3: Establish the WC-2701C flow path description method based on the flow direction description matrix, including:

[0157] (1) Use an I*J matrix M cold Describe the flow direction of the working fluid on the seawater side:

[0158]

[0159] Among them, M cold (1,16) , M cold (2,16) , M cold (3,16) , M cold (4,16) , M cold (5,16) , M cold (6,16) , M cold (7,16) , M cold (8,16) Indicates the flow direction of seawater in the inlet control unit, M cold (1,1) , M cold (2,1) , M cold (3,1) , M cold (4,1) , M cold (5,1) , M cold (6,1) , M cold (7,1) , M cold (8,1) Indicates the flow direction of seawater working fluid in the outlet control unit.

[0160] (2) Use an I*J matrix M hot Describe the flow direction of the working fluid on the natural gas side:

[0161]

[0162] Among them, M hot (1,1) , M hot (1,2) , M hot (1,3), M hot (1,4) , M hot (1,5) , M hot (1,6) , M hot (1,7) , M hot (1,8) Indicates the flow direction of natural gas in the inlet control unit, M hot (8,9) , M hot (8,10) , M hot (8,11) , M hot (8,12) , M hot (8,13) , M hot (8,14) , M hot (8,15) , M hot (8,16) Indicates the flow direction of natural gas working fluid in the outlet control unit.

[0163] Step 4: Establish the control equation of the WC-2701C control unit, taking the control unit C under working condition 1 as (1,16,1) For example, it includes:

[0164] (1) Establish the mass equation.

[0165] Table 4: Control unit C (1,16,1) Mass equation

[0166]

[0167] In the formula, the mass flow rate m is obtained by dividing the mass flow rate of the working fluid inlet by the total number of inlet control units, m cold is 2.643×10 -3 kg / s; m hot is 1.729×10 -2 kg / s. Control unit C (1,16,1) The outlet mass flow rate of the seawater side is transferred to C (1,15,1) The inlet of the gas side is passed to C (2,16,1) Entrance.

[0168] (2) Establish the energy equation.

[0169] Table 5: Control unit C (1,16,1) Energy equation

[0170]

[0171] In the formula, the physical properties of the working fluid are obtained by calling Prop.dll; the values ​​of heat exchange Q, outlet enthalpy h and logarithmic mean temperature difference ΔT are obtained by iterative calculation of the control unit; the value of the total heat transfer coefficient E is calculated by substituting the heat transfer correlation equations on the seawater side and the natural gas side. Through preliminary research and verification, the heat transfer correlation equations selected for WC-2701C natural gas and seawater working fluids are as follows:

[0172] Table 6: WC-2701C natural gas and seawater working fluid heat transfer correlation

[0173]

[0174] Where Nu, Re, and Pr represent the Nusselt number, Reynolds number, and Prandtl number, respectively. Control unit C (1,16,1) The outlet enthalpy of the seawater side is transferred to C (1,15,1) The inlet and outlet enthalpy of the natural gas side are transferred to C (2,16,1) Entrance.

[0175] (3) Establish the momentum equation:

[0176] Table 7: Control unit C (1,16,1) Momentum equation

[0177]

[0178] In the formula, the physical properties of the working fluid are obtained by calling Prop.dll; the value of Δp is calculated by substituting the flow correlation equations of the seawater side and the natural gas side. Through preliminary research and practice, the flow correlation equations selected for WC-2701C natural gas and seawater working fluids are as follows:

[0179] Table 8: WC-2701C natural gas and seawater working fluid flow correlation

[0180]

[0181] In the formula, f firc is the friction factor, Re is the Reynolds number. Control unit C (1,16,1) The outlet pressure of the seawater side is transmitted to C (1,15,1) The inlet of the gas side is transmitted to the outlet pressure of C (2,16,1) Entrance.

[0182] Step 5: Establish the solution algorithm of the control unit, including:

[0183] (1) Initialization of control units: Initialization of all control units in the three-dimensional array C[8]

[16]

[260] is completed according to the structural parameters and process parameters of the compressor aftercooler WC-2701C;

[0184] (2) Based on Figure 8The algorithm generates the iterative path of the WC-2701C control unit, and uses the method of alternating heat exchange and pressure drop iteration to traverse all the control units of C[8]

[16]

[260] and solve the control equations.

[0185] (3) Based on Fig. 9 , Fig.10 The algorithm solves the energy equation and momentum equation of each control unit in C[8]

[16]

[260] , taking the control unit C under working condition 1 as (1,1,1) Taking the first iteration as an example, the iterative process of the fast solution algorithm for the energy equation based on the dichotomy method is as follows:

[0186] Table 9: Control unit C based on dichotomy (1,1,1) Energy equation iteration process example

[0187]

[0188] When the program iterates to the 12th time, control unit C (1,1,1) That is, the convergence condition is met, and the control unit C can be obtained. (1,1,1) All parameters in the energy equation:

[0189] Table 10: Control unit C (1,1,1) Energy equation solution results

[0190]

[0191]

[0192] Step 6: Follow the above steps to complete the iteration of all control units in C[8]

[16]

[260] . After one iteration, the convergence judgment is made. If the convergence condition is not met, the iteration is repeated until convergence. Taking working condition 1 as an example, when the algorithm iterates for the 23rd time, the convergence condition is met. At this time, the thermal performance simulation of the heat exchanger ends and the simulation results are output.

[0193] The advantages of applying the present invention to the simulation of the thermal performance of a printed circuit board type heat exchanger are explained below by combining the performance simulation results of the compressor aftercooler WC-2701C in this example with the actual production data of WC-2701C in a certain offshore gas field in China and the CFD numerical calculation results.

[0194] (1) The performance simulation results of the present invention are compared with the actual production data of the heat exchanger. The results show that the calculation deviation of the heat exchange power is less than 4.67%, and the pressure drop deviation is less than 7.89%. The performance simulation results meet the requirements of engineering applications.

[0195] Table 11: Comparison of performance simulation results and actual production data (operating condition 1)

[0196]

[0197] Table 12: Comparison of performance simulation results and actual production data (operating condition 2)

[0198]

[0199] (2) The performance simulation results of the present invention were compared with those of CFD software. The results showed that the calculation deviation of the heat exchange power was less than 2.24%, and the calculation deviation of the pressure drop was less than 7.46%. At the same time, the calculation time of the performance simulation method of the present invention was nearly 20 times faster than that of CFD, which greatly improved the calculation efficiency while taking into account the calculation accuracy.

[0200] Table 13: Comparison of performance simulation results and CFD calculation results (condition 1)

[0201]

[0202] Table 14: Comparison of performance simulation results and CFD calculations (condition 2)

[0203]

[0204] (3) The thermal performance simulation method of the present invention can solve the inlet and outlet parameters of all control units of the printed circuit board heat exchanger, and solve the problem that the existing lumped parameter model and distributed parameter model cannot calculate the cross-flow heat transfer, and can obtain the same three-dimensional temperature and pressure cloud map as the CFD software, such as Figures 12 to 16 shown.

[0205] Embodiment 2: This embodiment provides an electronic device corresponding to the method for simulating thermal performance of a printed circuit board type heat exchanger provided in Embodiment 1. The electronic device may be an electronic device for a client, such as a mobile phone, a laptop computer, a tablet computer, a desktop computer, etc., to execute the method of Embodiment 1. Fig.17 As shown, the electronic device includes a processor, a memory, a communication interface and a bus, and the processor, the memory and the communication interface are connected through the bus to complete mutual communication. The memory stores a computer program that can be run on the processor, and the processor executes the method of embodiment 1 when running the computer program. Its implementation principle and technical effect are similar to those of embodiment 1, and will not be repeated here.

[0206] Embodiment 3: This embodiment provides a computer-readable storage medium storing one or more programs, wherein the one or more programs include computer instructions. When the computer instructions are executed by a computer, the computer executes the method provided in the above-mentioned embodiment 1.

[0207] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for simulating thermal performance of a printed circuit board type heat exchanger, characterized in that: include: Establish dynamic physical property calling method to form dynamic link library; A three-dimensional distributed parameter model is established according to the structural dimensions of the printed circuit board heat exchanger, and a three-dimensional array C[I][J][K] is used to represent all control units of the heat exchanger, where each array element C (i,j,k) Represents an independent control unit; Establish a flow direction description matrix of the cold and hot side working fluids in the printed circuit board type heat exchanger control unit; Based on the dynamic link library and the flow direction description matrix, each control unit C is established (i,j,k) Control equations of the cold and hot side working fluids; Establish the simulation iteration algorithm of printed circuit board heat exchanger for all control units C (i,j,k) The control equations of the cold and hot side working fluids are iteratively solved. When the convergence conditions are met, the thermal performance simulation ends and the simulation results are output.

2. The method for simulating thermal performance of a printed circuit board type heat exchanger according to claim 1, characterized in that: Establish dynamic property calling method to form dynamic link library, including: Through the secondary development of Aspen HYSYS software, the physical property calling method for the built-in physical property package of Aspen HYSYS is established and a dynamic link library is formed; The input and reading of physical property data of different working fluids are realized by real-time calling of dynamic link libraries, including inputting the temperature and pressure parameters of the working fluid to solve the enthalpy value, inputting the pressure and enthalpy value of the working fluid to solve the dryness, temperature, density, specific heat capacity, dynamic viscosity and / or thermal conductivity.

3. The method for simulating thermal performance of a printed circuit board type heat exchanger according to claim 1, characterized in that: A three-dimensional distributed parameter model is established according to the structural dimensions of the printed circuit board type heat exchanger, and the three-dimensional array is used to represent all the control units of the heat exchanger using C[I][J][K], including: The geometric model of the printed circuit board type heat exchanger is established according to the input direct structural parameters of the printed circuit board type heat exchanger; The core of the printed circuit board heat exchanger is divided into K heat exchange units, and a heat exchange unit generally includes a cold side heat exchange plate and a hot side heat exchange plate; Each heat exchange unit is divided into I*J control units. Each control unit consists of three parts: cold side channel, hot side channel and wall surface. The control units located in the triangular areas at both ends of the core are cross-flow heat exchangers, and the control units in the middle area are counter-flow heat exchangers. A three-dimensional array C[I][J][K] is used to describe all the control units of the heat exchanger. I, J, and K represent the number of control units of the heat exchanger core in the x, y, and z directions, respectively. Each array element C (i,j,k) Represents an independent control unit in the core. All control units in the three-dimensional array C[I][J][K] together constitute a three-dimensional distributed parameter model of the heat exchanger, where x is the width, y is the length, and z is the height.

4. The method for simulating thermal performance of a printed circuit board type heat exchanger according to claim 3, characterized in that: Establish the flow direction description matrix of the cold and hot side working fluids in the printed circuit board heat exchanger control unit, including: Use two I*J matrices M cold and M hot Describe the flow direction of the cold and hot side working fluids in their respective heat exchange units, I represents the number of control units along the x direction of the core, and J represents the number of control units along the y direction of the core; According to the geometric model, the matrix M cold The element M cold (i,j) is assigned, M cold (i, j) is composed of a three-dimensional vector, representing the flow direction of the medium in the control unit, M cold The value of (i,j) is determined by the following formula: Among them, (1,0,0), (-1,0,0) represent the cold side working fluid in control unit C (i,j,k) The flow is in the x direction, (0,1,0), (0,-1,0) represents the cold side working fluid in the control unit C (i,j,k) The flow is along the y direction, (0,0,1), (0,0,-1) represents the cold side working fluid in the control unit C (i,j,k) The internal flow is in the z direction; Repeat the above process and calculate the matrix M according to the geometric model. hot The element M hot (i,j) is assigned.

5. The method for simulating thermal performance of a printed circuit board type heat exchanger according to claim 4, characterized in that: Based on the dynamic link library and the flow direction description matrix, each control unit C is established (i,j,k) The control equations of the cold and hot side working fluids include: Establish the energy equation describing the energy transfer between the cold and hot sides: Energy Conservation Equation: Q (i,j,k) =m (i,j,k) ·(h out,(i,j,k) -h in,(i,j,k) ); Heat Transfer Equation: Q (i,j,k) =E (i,j,k) A (i,j,k) ΔT (i,j,k) ; (i',j',k')=(i,j,k)+M(i,j); h in,(i',j',k') =h out,(i,j,k) ; Where Q is the heat transfer, W; m is the mass flow rate, kg / s; h is the mass specific enthalpy, J / kg; ΔT is the logarithmic mean temperature difference of the control unit, °C; E is the total heat transfer coefficient of the control unit, W / (m 2 ·℃); A represents the effective heat exchange area of ​​the control unit, m 2 ; The subscripts in and out represent the inlet and outlet of the control unit respectively; i, j, k represent the control unit C (i,j,k) The position numbers in the three-dimensional array C[I][J][K], i', j', k' represent the position numbers of the control unit C (i,j,k) The position number of the next control unit connected to the outlet, M(i,j) is the matrix element. For the cold side working fluid, M(i,j) is from the matrix M cold For the hot side working fluid, M(i,j) is taken from the matrix M hot Take the value in The momentum equation describing the momentum transfer of the working fluid on the cold and hot sides is established: p out,(i,j,k) =p in,(i,j,k) -Δp (i,j,k) ; (i',j',k')=(i,j,k)+M(i,j); p in,(i',j',k') =p out,(i,j,k) ; Wherein, p represents pressure, kPa; Δp represents pressure drop, kPa.

6. The method for simulating thermal performance of a printed circuit board type heat exchanger according to claim 5, characterized in that: Establish the simulation iteration algorithm of printed circuit board heat exchanger for all control units C (i,j,k) The control equations are solved iteratively. When the convergence conditions are met, the thermal performance simulation ends and the results are output, including: S1. Initialize all control units in C[I][J][K]; S2. Describe the matrix M according to the flow direction of the cold and hot side flow paths hot 、M cold Realize all control units C in the heat exchanger (i,j,k) The traversal process is the process of solving the control equation of each control unit. The specific process is: S21, setting the control unit number to i=1, j=1, k=1; S22. Solve the energy equation of the current control unit C (i,j,k) and, according to the value of M(i, j) in the flow direction description matrix, transfer the outlet enthalpy value of C (i,j,k) to the downstream control unit C (i’,j’,k’) ; when i < I, then i = i + 1 and continue the loop iteration, and sequentially complete the traversal of all control units in the width direction of the heat exchanger according to the above method; when j < J, set i = 1, j = j + 1 and continue the loop iteration to complete the traversal of all control units in the length direction of the heat exchanger; when k < K, set i = 1, j = 1, k = k + 1 and continue the loop iteration to complete the traversal of all control units in the height direction of the heat exchanger; S23, after completing the solution of the energy equations of all control units, start solving the momentum equation, and set the control unit numbers to i=1, j=1, k=1; S24. Solve the momentum equation of the current control unit C (i,j,k) and, according to the value of M(i, j) in the flow direction description matrix, transfer the outlet pressure of C (i,j,k) to the downstream control unit C (i’,j’,k’) ; when i < I, then i = i + 1, and traverse all the control units in the width direction of the heat exchanger in turn according to the above method; when j < J, let i = 1, j = j + 1, and complete the traversal of all the control units in the length direction of the heat exchanger; when k < K, let i = 1, j = 1, k = k + 1, and complete the traversal of all the control units in the height direction of the heat exchanger; S25, complete all control units C in C[I][J][K] (i,j,k) After solving the energy equation and momentum equation, a convergence judgment is performed. When the convergence condition is met, the iteration is completed and the simulation results are output; when the iteration convergence condition is not met, steps S21-S24 are repeated until the iteration convergence condition is met.

7. The method for simulating thermal performance of a printed circuit board type heat exchanger according to claim 6, characterized in that: The algorithm process for solving the energy equation of the control unit in S22 is: S221, obtain the control unit C (i,j,k) The inlet process parameters; S222, according to control unit C (i,j,k) The maximum heat transfer Q is obtained by using the inlet process parameters max , set the minimum heat transfer Q min The initial value of is 0; S223, obtaining the physical property parameters of the working fluid by calling the dynamic link library, selecting the corresponding heat transfer correlation equation according to the working fluid type and process parameters, and calculating the total heat transfer coefficient E; S224, set the initial value of heat exchange Q = (Q min +Q max ) / 2, and solve the outlet parameters of the cold and hot sides of the control unit according to the energy conservation equation, and obtain the logarithmic mean temperature difference of the control unit ΔT1=(Δt max -Δt min ) / ln(Δt max / Δt min ), Δt max , Δt min They are the maximum and minimum values ​​of the temperature difference between the two end surfaces of the control unit respectively; S225, solving the heat transfer equation to obtain the logarithmic mean temperature difference of the control unit ΔT2 = Q / EA; S226, determine whether the deviation values ​​of ΔT1 and ΔT2 meet the convergence condition. If so, the iteration is terminated and the control unit C is updated. (i,j,k) The outlet enthalpy of the working fluid on the cold and hot sides; S227, if the convergence condition is not met, then determine the size of ΔT1 and ΔT2, and when ΔT1>ΔT2, assign Q to Q min , repeat steps S224-S225; when ΔT1<ΔT2, assign Q to Q max , repeat steps S224-S225; until the iteration meets the convergence condition.

8. The method for simulating thermal performance of a printed circuit board type heat exchanger according to claim 6, characterized in that: The process of solving the momentum equation of the control unit in S24 is: S241, obtain control unit C (i,j,k) The input parameters of S242, obtaining the physical property parameters of the working fluid by calling the dynamic link library, selecting a suitable flow correlation equation according to the working fluid type and process parameters, and calculating the pressure drop Δp of the working fluid on the cold and hot sides respectively; S243, update control unit C (i,j,k) The outlet pressure of the working fluid on the cold and hot sides.

9. An electronic device, characterized in that: include: at least one processor; as well as A memory communicatively connected to the processor; wherein, The memory stores instructions executable by the processor, and the instructions are executed by the processor to enable the processor to perform the method according to any one of claims 1 to 8.

10. A computer-readable storage medium storing one or more programs, characterized in that: The one or more programs include computer instructions for causing a computer to execute the method according to any one of claims 1-8.

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