Parameter simulation method and system for coaxial turbine expansion and compression integrated equipment

Abstract

The invention relates to the technical field of petrochemical engineering, in particular to a parameter simulation method and system for coaxial turbo expansion and compression integrated equipment, and the method comprises the steps: obtaining the inlet material information and operation parameters of each stage of turbo expander and turbo compressor according to VxOTS; the operating parameters comprise shafting friction parameters associated with the rotating speed of the shaft; simulation training is carried out according to all the import material information, the operation parameters and the shaft rotating speed of the coupler with the specified initial value, and the equipment performance parameters and the shaft rotating speed of the coupler obtained through simulation training in the round are obtained; when it is determined that the performance parameters of the equipment do not reach the end condition, next simulation is carried out, and in Mth simulation training, the Mth shaft rotating speed is calculated by using the (M-1) th shaft rotating speed; carrying out simulation training by using the M-th imported material information, the shaft rotating speed and the operation parameters until the output equipment performance parameters reach an end condition; and taking the coaxial turbine expansion and compression integrated equipment obtained by simulation training as equipment in a dynamic simulation operation and use process.

Description

Technical Field

[0001] The present invention relates to the technical field of petrochemical industry, and in particular to a parameter simulation method and system for a coaxial turbine expansion and compression integrated device. Background Art

[0002] At present, process simulation can simulate the dynamic changes of the entire process in the actual industrial production process. Because it is close to the actual working conditions and easy to deploy, it is widely used in operation training and digital twins.

[0003] When modeling basic turbine expansion and compression equipment, the turbine expander and turbine compressor are often modeled separately. A custom module is used to convert the power of the two components, calculating the corresponding compressor speed for the same power. In actual operation, the operating conditions of turbine expanders and turbine compressors vary continuously. When these operating parameters change, the turbine compressor speed must be adjusted accordingly to maintain the same power as the turbine expander, based on the power conversion relationship. For example, if the intake flow increases, the turbine compressor speed may need to be increased to ensure power balance, resulting in a difference between the turbine compressor speed and the turboexpander speed.

[0004] However, when the two are coaxial, the shaft speed should be the same. If the shaft speeds used by the two are different, it may cause errors in the simulation, and the referenced data cannot be effectively linked with the simulation data of the previous wheel, causing the model to be prone to data breakpoints, model instability and other errors under extreme working conditions (such as sudden flow changes, compressor surge, etc.). Summary of the Invention

[0005] (1) Technical issues to be resolved

[0006] In view of the above-mentioned shortcomings and deficiencies of the prior art, the present invention provides a parameter simulation method and system for a coaxial turbine expansion and compression integrated device, which solves the technical problem that the existing middle shaft speed and the upper wheel simulation data cannot be effectively linked, resulting in model instability.

[0007] (2) Technical solution

[0008] In order to achieve the above objectives, the main technical solutions adopted by the present invention include:

[0009] In the first aspect, a parameter simulation method for a coaxial turbine expansion and compression integrated device proposed in an embodiment of the present invention includes an N-stage turbine expander and a P-stage turbine compressor connected by a coaxial rigid coupling, where N and P are both integers greater than 0. The method includes: 100, obtaining the inlet material information and operating parameters of each stage of the turbine expander and each stage of the turbine compressor according to the operator training system VxOTS; wherein the operating parameters include the shaft friction parameters associated with the shaft speed; 200, performing simulation training based on all the inlet material information, operating parameters and the shaft speed of the coupling with a specified initial value. 300. When it is determined that the equipment performance parameters have not reached the end condition, the next simulation training is carried out. In the M-th simulation training, the shaft speed obtained for the M-1th time is used to calculate the shaft speed of the M-th coupling. The M-th imported material information, the shaft speed and the operating parameters are used for simulation training until the output equipment performance parameters reach the end condition. M is an integer greater than 1. 400. The coaxial turbine expansion and compression integrated device obtained from the simulation training is used as a device for dynamically simulating the performance parameters during operation.

[0010] Optionally, the method further includes: obtaining the increase value of the shaft speed of the coupling in the Mth simulation training and the shaft speed output by the M-1th simulation training; adding the increase value of the Mth simulation training to the shaft speed output by the M-1th simulation training to obtain the shaft speed of the Mth simulation training; wherein, the increase value of the shaft speed of the Mth simulation training is obtained based on the total power of the turbine expander, the total power of the turbine compressor, the shaft friction loss power and the preset moment of inertia of the coupling obtained within the set time of the Mth simulation training; The total power of the turbine expander is the Mth total power of all turbine expanders calculated based on the shaft speed output by the M-1th simulation training and the imported material information and operating parameters of the N-stage turbine expander; the total power of the turbine compressor is the Mth total power of all turbine compressors calculated based on the shaft speed output by the M-1th simulation training and the imported material information and operating parameters of the P-stage turbine compressor; the shaft friction loss power is the loss power of the coupling obtained based on the shaft speed output by the M-1th simulation training and the shaft friction parameters.

[0011] Optionally, obtaining the increase value of the shaft speed of the coupling in the Mth simulation training also includes: obtaining the adjustment coefficient of the Mth simulation training; subtracting the total power of the turbine expander and the total power of the turbine compressor in the Mth simulation training to obtain a first difference; subtracting the first difference of the Mth simulation training from the friction loss power of the shaft system to obtain the shaft balance power of the Mth simulation training; dividing the shaft balance power of the Mth simulation training by the product of the adjustment coefficient and the moment of inertia to determine the increase value of the shaft speed of the coupling in the Mth simulation training.

[0012] Optionally, obtaining the adjustment coefficient of the Mth simulation training includes: obtaining the historical shaft speed of the Mth rotation in the historical speed data, and its corresponding shaft balance power; determining a second difference by using the difference between the shaft balance power of the Mth simulation training and the shaft balance power corresponding to the historical shaft speed of the Mth rotation in the historical speed data; determining a third difference by using the difference between the shaft speed output of the M-1th simulation training and the historical shaft speed of the Mth rotation in the historical speed data; and dividing the second difference by the moment of inertia to obtain a first intermediate value; and determining the adjustment coefficient of the Mth simulation training by dividing the first intermediate value by the third difference.

[0013] Optionally, before obtaining the first difference by subtracting the total power of the turbine expander and the total power of the turbine compressor obtained by the M-th simulation training, the method further includes: determining the inlet enthalpy value, outlet enthalpy value, turbine compressor flow rate and turbine compressor thermal efficiency of the turbine compressor in the M-th simulation training; wherein the inlet enthalpy value, the outlet enthalpy value and the turbine compressor flow rate are obtained by simultaneously solving the inlet material information, operating parameters and shaft speed output of the turbine compressor in the M-1-th simulation training based on the capacity balance mechanism; the turbine compressor thermal efficiency is obtained based on the M-1-th simulation training. The shaft speed output by the 1st simulation training and the turbine compressor flow rate of the Mth simulation training are obtained; the fourth difference value is obtained by using the difference between the outlet enthalpy value and the inlet enthalpy value of the turbine compressor; the first value of the Mth simulation training is obtained by multiplying the fourth difference value by the turbine compressor flow rate of the Mth simulation training; the turbine compressor power of the turbine compressor is determined by dividing the first value by the turbine compressor thermal efficiency; the turbine compressor power of the P-level turbine compressor of the Mth simulation training is accumulated to obtain the total power of the turbine compressor of the Mth simulation training.

[0014] Optionally, before obtaining the first difference by subtracting the total power of the turbine expander obtained by the M-th simulation training from the total power of the turbine expander, the method further includes: determining an inlet enthalpy value, an outlet enthalpy value, a turbine expander flow rate, and a turbine expander thermal efficiency of the turbine expander in the M-th simulation training; wherein the inlet enthalpy value, the outlet enthalpy value, and the turbine expander flow rate are obtained by simultaneously solving the inlet material information, operating parameters, and shaft speed output by the M-1-th simulation training of the turbine expander based on a capacity balance mechanism; and the turbine expander thermal efficiency is obtained based on the shaft speed output by the M-1-th simulation training and the turbine expander flow rate of the M-th simulation training.

[0015] Subtracting the outlet enthalpy value from the inlet enthalpy value of the turboexpander to obtain a fifth difference value of the M-th simulation training;

[0016] Dividing the fifth difference by the turbine expander flow rate of the M-th simulation training to obtain a second product of the M-th simulation training;

[0017] multiplying the turboexpander thermal efficiency by the second product to determine a turboexpander power of the turboexpander;

[0018] The turbine expander powers of the N-stage turbine expanders in the M-th simulation training are accumulated to obtain the total power of the turbine expander in the M-th simulation training.

[0019] Optionally, before obtaining the shaft balance power of the Mth simulation training by subtracting the first difference value of the Mth simulation training from the shaft friction loss power, the method further includes: obtaining the shaft friction loss power by using the shaft friction parameter and the shaft speed output by the M-1th simulation training, combined with the given static friction starting power of the coupling.

[0020] Optionally, the method further includes: using a coaxial turbine expansion and compression integrated device that meets the termination conditions to perform simulation prediction based on the inlet material information of each stage of turbine expanders and turbine compressors to obtain the outlet material information of each stage of turbine expanders and turbine compressors.

[0021] Optionally, the operating parameters also include at least one of the following: moment of inertia, maximum acceleration rate, maximum deceleration rate; the import logistics information includes at least one of the following: temperature, pressure, flow rate, and component.

[0022] In the second aspect, an embodiment of the present invention proposes a parameter simulation system for a coaxial turbine expansion-compression integrated device, comprising a memory, a processor, and a computer program stored on the memory, wherein the processor executes the computer program to implement a parameter simulation method for a coaxial turbine expansion-compression integrated device as described in any one of the above items.

[0023] (3) Beneficial effects

[0024] The beneficial effects of the present invention are as follows: a parameter simulation method for a coaxial turbine expansion and compression integrated device utilizes an operator training system (VxOTS) to obtain inlet material information and operating parameters for each stage of the turbine expander and each stage of the turbine compressor; the operating parameters include shaft friction parameters associated with the shaft speed; and simulation training is performed based on all the inlet material information, operating parameters, and the shaft speed of the coupling with a specified initial value to obtain the device performance parameters and the shaft speed of the coupling obtained in that round of simulation training. In other words, the present invention updates the shaft speed in each round, using the shaft speed output at the M-1th round to obtain the shaft speed for the Mth round of simulation training. This not only effectively links the shaft speed output at the M-1th round with the data obtained at the Mth round, avoiding the error accumulation caused by the independent calculation of each stage of the turbine expander and turbine compressor, thereby approximating the actual operating state of the coaxial turbine expansion and compression integrated device, but also avoids iterative errors caused by using a fixed shaft speed, thereby preventing model oscillation and improving the dynamic robustness of the coaxial turbine expansion and compression integrated device. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A schematic structural diagram of a coaxial turbine expansion and compression integrated device provided by the prior art;

[0026] Figure 2 A schematic flow chart of a parameter simulation method for a coaxial turbine expansion-compression integrated device provided in an embodiment of the present invention;

[0027] Figure 3 A schematic diagram of an information input interface provided by an embodiment of the present invention;

[0028] Figure 4 A schematic flow chart of another parameter simulation method for a coaxial turbine expansion-compression integrated device provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0029] The Operator Training System (OTS) can be used to simulate industrial equipment in the entire industrial process, simulating real production equipment and control systems, thereby optimizing the operating parameters of the equipment and avoiding the waste of raw materials during actual debugging.

[0030] For example, in some projects, a coaxial turbine expansion and compression integrated device is required, that is, an N-stage turbine expander and a P-stage turbine compressor are connected through a coaxial rigid coupling. Figure 1 , Figure 1The coupling of the coaxial turbine expansion and compression integrated device shown is equipped with a two-stage turbine expander and a three-stage turbine compressor. Each stage of the turbine expander and turbine compressor is connected to an inlet stream and an outlet stream. The main function of the turbine expander is to utilize high-pressure gas entering the turbine expander impeller flow path, where it expands within the gradually diverging flow path to perform external work. The internal energy is converted into mechanical energy through the impeller work, significantly reducing the pressure and temperature of the gas, achieving the purpose of refrigeration and cooling. The mechanical work output by the turbine expander is transmitted to the turbine compressor through the coaxial rigid coupling. The compressor impeller is driven by the coaxial power to rotate at high speed, and the gas is accelerated in the centrifugal force field and enters the diffuser, where the mechanical energy is converted into high-pressure potential energy.

[0031] When simulating a coaxial turbine expander-compressor integrated device, researchers typically model the turbine expander and turbine compressor separately and use custom modules to convert their power. This allows them to calculate the corresponding speeds for the turbine expander and turbine compressor, assuming the power of the two is the same. However, the operating conditions of turbine expanders and turbine compressors vary greatly during actual operation. When these operating parameters change, the speeds are adjusted accordingly based on the power conversion relationship to maintain the same power between the turbine compressor and the turbine expander. For example, an increase in intake air flow may require an increase in the turbine compressor speed, resulting in a difference between the turbine compressor speed and the turbine expander speed.

[0032] However, because the turbocompressors and turboexpanders in a coaxial turboexpander-compressor system are coaxial, their rotation is driven by a coupling and should be the same speed. If the two are different, the OTS may experience excessively high bit error rates during subsequent simulations. Furthermore, the referenced data in the custom formulas cannot be effectively linked to the previous data, making the model prone to errors such as data breakpoints and model instability under extreme operating conditions (such as sudden flow changes and compressor surge).

[0033] The present invention utilizes the operator training system VxOTS to obtain the inlet material information and operating parameters for each stage of the turboexpander and turbocompressor. The operating parameters include shaft friction parameters associated with the shaft speed. Simulation training is then performed based on all the inlet material information, operating parameters, and the shaft speed of the coupling with a specified initial value to obtain the device performance parameters and the shaft speed of the coupling obtained during the simulation training. In other words, the present invention updates the shaft speed in each round and uses the shaft speed and operating parameters outputted during the Mth round of simulation training. This not only effectively links the shaft speed with the data obtained during the Mth round, avoiding the accumulation of errors caused by independent calculations of each stage of the turboexpander and turbocompressor, thereby approximating the actual operating state of the coaxial turboexpander-compressor integrated device, but also avoids iterative errors caused by using a fixed shaft speed, thereby preventing model oscillation and improving the dynamic robustness of the coaxial turboexpander-compressor integrated device.

[0034] In order to better explain the present invention and facilitate understanding, the present invention is described in detail below through specific implementation methods in conjunction with the accompanying drawings.

[0035] In order to solve the above problems, the present invention provides a parameter simulation method for a coaxial turbine expansion and compression integrated device, which is applied to VxOTS. For details, please refer to Figure 2 ,like Figure 2 As shown, the method includes:

[0036] 100. Obtaining the inlet material information and operating parameters of each stage of the turboexpander and each stage of the turbocompressor according to the operator training system VxOTS; wherein the operating parameters include shaft friction parameters associated with the shaft speed;

[0037] 200. Perform simulation training based on all imported material information, operating parameters, and the shaft speed of the coupling with the specified initial value, and obtain the equipment performance parameters and the shaft speed of the coupling obtained from the simulation training in this round;

[0038] 300. When it is determined that the equipment performance parameter has not reached the termination condition, the next simulation training is performed. In the Mth simulation training, the shaft speed obtained in the M-1th simulation training is used to calculate the shaft speed of the Mth coupling; the simulation training is performed using the Mth imported material information, the shaft speed, and the operating parameters until the output equipment performance parameter reaches the termination condition; wherein M is an integer greater than 1;

[0039] 400. The coaxial turbine expansion and compression integrated device obtained through simulation training is used as a device for dynamically simulating performance parameters during operation.

[0040] Specifically, in this embodiment, VxOTS can be used to first obtain the inlet material information and operating parameters of each level of turbo expanders and turbo compressors. Among them, the inlet material information includes but is not limited to at least one of the following: temperature, pressure, material composition, and molar flow rate. The operating parameters can be understood as controllable parameters that affect the operating state and performance of the equipment, including at least the shaft friction coefficient. Since the coupling drives the turbo compressor and turbo expander to rotate, the turbo compressor and turbo expander may have shaft friction with the coupling, thereby affecting the shaft speed. Furthermore, the operating parameters may also include but are not limited to at least one of the following: the number of turbo compressor stages, the number of turbo expander stages, the moment of inertia, the maximum acceleration rate, the maximum deceleration rate, and the static friction starting power.

[0041] For easier understanding, please refer to Figure 1 and Figure 2 ,like Figure 2 As shown, the number of turbine compressor stages can be 3, and the number of turbine expander stages can be 2. For specific structures, please refer to Figure 1 Coaxial turbine expansion and compression integrated equipment. Figure 1 and Figure 2 IN_1 and IN_2 are the inlet material information of the two turbo expanders, and IN_3, IN_4, and IN_5 are the inlet material information of the three turbo compressors. The moment of inertia can be set to 3800 kg × m 2 , the maximum acceleration rate is 60rpm and the maximum deceleration rate is 60rpm.

[0042] Next, after obtaining all the import logistics information, operating parameters and shaft speed of the coupling, multiple rounds of simulation training can be carried out using the import logistics information, operating parameters and shaft speed. During the training process, VxOTS can output the equipment performance parameters and updated shaft speed of each round. Furthermore, it can be determined whether the equipment performance parameters meet the end conditions. If they do not meet the end conditions, the next round of simulation will be continued, and the shaft speed for the next simulation training can be obtained based on the shaft speed obtained in this round. Specifically, the shaft speed for the Mth simulation training can be obtained based on the shaft speed output for the M-1th time. That is, in this embodiment, the shaft speed obtained in the previous simulation training is put into use as the shaft speed for this simulation training, rather than setting a fixed shaft speed as in the prior art, thereby avoiding ignoring other influencing factors of the acceleration process (such as shaft friction), thereby avoiding the simulated equipment being out of touch with reality.

[0043] The termination conditions include, but are not limited to, at least one of the following: the rate of change of each device performance parameter is less than a parameter change threshold, the difference between each device performance parameter and a historical device performance parameter is less than a parameter difference threshold, or a stop command is received. Device performance parameters include, but are not limited to, at least one of the following: coupling shaft speed, cooling output, working fluid dryness, exhaust temperature, and flow margin.

[0044] If the rate of change of each parameter in the equipment performance parameters is lower than the parameter change threshold, or the difference between each parameter in the equipment performance parameters and the historical equipment performance parameters is lower than the parameter difference threshold, then it can be considered that the current equipment performance parameters are relatively close to the actual operating state of the coaxial turbine expansion and compression integrated device. At this time, the coaxial turbine expansion and compression integrated device simulated by VxOTS has reached a stable and optimal operating state. At this time, the coaxial turbine expansion and compression integrated device simulated by VxOTS can be used for parameter verification and performance evaluation. For example, the operation under the current load can be simulated by the coaxial turbine expansion and compression integrated device that meets the end conditions, and the range of changes in shaft speed, pressure ratio, and shaft power can be evaluated to avoid surge or low-efficiency operation. For example, the coaxial turbine expansion and compression integrated device that meets the end conditions can be used to simulate and predict based on the inlet material information of each stage of turbine expanders and turbine compressors to obtain the outlet material information of each stage of turbine expanders and turbine compressors, that is, Figure 1 and Figure 2 OUT_1, OUT_2, OUT_3, OUT_4, and OUT_5 in the figure. The physical behavior of the device is converted into predictable indicators, thereby improving the operating efficiency of the actual coaxial turbine expansion and compression integrated device.

[0045] Optionally, the end condition may be simply receiving a stop command, that is, even if the current device is close to the operating state of the actual coaxial turbine expansion and compression integrated device, the simulation training will not stop, but will continue to simulate until a stop command is received.

[0046] In step 300, if the coaxial turbine expansion and compression integrated device does not meet the end condition and needs to proceed to the next round of simulation, the specific steps include:

[0047] 3001, obtaining an increase value of the shaft speed of the coupling in the Mth simulation training and the shaft speed output in the M-1th simulation training;

[0048] 3002, adding the increment value of the Mth simulation training to the shaft speed outputted from the M-1th simulation training to obtain the shaft speed of the Mth simulation training;

[0049] Among them, the increase value of the shaft speed of the Mth simulation training is obtained based on the total power of the turbine expander, the total power of the turbine compressor, the shaft friction loss power and the preset rotational inertia of the coupling obtained within the set time of the Mth simulation training; the total power of the turbine expander is the Mth total power of all turbine expanders calculated based on the shaft speed output by the M-1th simulation training and the imported material information and operating parameters of the N-stage turbine expander; the total power of the turbine compressor is the Mth total power of all turbine compressors calculated based on the shaft speed output by the M-1th simulation training and the imported material information and operating parameters of the P-stage turbine compressor; the shaft friction loss power is the loss power of the coupling obtained based on the shaft speed output by the M-1th simulation training and the shaft friction parameters.

[0050] Specifically, in the actual use of the coaxial turbine expansion and compression integrated device, each rotation of the shaft speed may be affected by many factors such as shaft friction, equipment power, and energy consumption. This embodiment uses the number of rotations of the coupling as a division, combines the number of rotations of the coupling of the actual device with the rounds of simulation training (for example, the 10th rotation of the coupling corresponds to the 9th round of simulation training), and uses the actual historical shaft speed of the coupling to participate in the optimization process of the shaft speed of the corresponding round of simulation training (described in detail later). In order to improve the closeness between the simulated shaft speed and the actual shaft speed during the simulation process (that is, to make the shaft speed of the 9th simulation training close to the shaft speed of the actual coupling rotation 10th round), this embodiment sets different increase values ​​for the shaft speed of each round for adjustment, and the increase value is obtained based on the factors that actually affect the coupling shaft speed (for example, turbine expander power, turbine compressor power, and shaft friction loss power). After obtaining the amplification value for the Mth simulation run, this amplification value is added to the shaft speed output from the M-1th simulation run to obtain the shaft speed for the Mth simulation run. This comprehensively considers the impact of actual operation on the shaft speed, making the shaft speed used in each simulation run more realistic, thereby improving the VxOTS simulation accuracy of the coaxial turbine expansion-compression integrated device and enhancing the reliability of the simulated coaxial turbine expansion-compression integrated device.

[0051] It should be noted that this embodiment does not specifically limit the method for obtaining the increment value.

[0052] In an illustrative embodiment, the adjustment coefficient of the Mth simulation training can be obtained. The adjustment coefficient can be linked to the factors that actually affect the shaft speed of the coupling, that is, the total power of the turbine expander and the total power of the turbine compressor of the Mth simulation training are used to make a difference to obtain a first difference; the first difference of the Mth simulation training is used to make a difference with the friction loss power of the shaft system to obtain the shaft balance power of the Mth simulation training; the shaft balance power of the Mth simulation training is divided by the product of the adjustment coefficient and the moment of inertia to determine the increase value of the shaft speed of the coupling of the Mth simulation training. The specific relationship can be satisfied as follows:

[0053]

[0054] Δn is the increase value obtained from the Mth simulation training; It is the adjustment coefficient of the Mth simulation training; f(n) is the relationship between the shaft speed of the Mth simulation training and the factors affecting the coupling shaft speed.

[0055] Where f(n) is related to the type of factors that affect the coupling shaft speed. For example, the following relationship can be obtained based on the shaft power balance:

[0056]

[0057] J is the moment of inertia; n is the shaft speed; B e is the total power of the turbo expander; B c is the total power of the turbine compressor; B f is the shafting friction loss power; That is Δn.

[0058] According to the above formula 2, the increase value Δn and the factors affecting the coupling shaft speed (i.e. the moment of inertia J in formula 2, the total power of the turbine expander B e , total power of turbine compressor B c , shaft friction loss power B f ) is the relationship f(n), that is, Δn=f(n).

[0059] If the next wheel shaft speed is obtained according to Δn=f(n), we can get:

[0060]

[0061] Total power of turbine compressor B c Generally related to the cube of the shaft speed n (B c ∝n 3 ), shaft friction loss power B e Related to the square of the shaft speed n (B f ∝n 2), on this basis, taking the slope of f(n) on n as the derivative of f(n), the above formula can be approximated as:

[0062]

[0063] According to formula (3), formula (1) can be obtained.

[0064] Calculating the slope of f(n) at n is crucial. Therefore, it is necessary to record the f(n) values ​​corresponding to historical shaft speeds (this can be obtained from historical turbine expander total power, historical turbine compressor total power, and historical shaft friction loss power, or by measurement). Calculations are performed using historical data from the coaxial turbine expander-compressor integrated device that is close to the M-1th shaft speed during actual operation (for example, the shaft speed of the Mth rotation of the coupling of the coaxial turbine expander-compressor integrated device during actual operation). This means calculating within the local approximate linear range of f(n), thereby reducing errors caused by nonlinearity and making the resulting adjustment coefficient more accurate. Furthermore, the shaft speed of the device varies relatively continuously during actual operation. Calculating based on the shaft speed of the Mth rotation during actual operation makes the model closer to the actual physical process, making the calculated speed increase value more realistic. Furthermore, this embodiment further calibrates the shaft speed calculation method to avoid model oscillation caused by iterative errors resulting from the use of historical data, thereby improving the dynamic robustness of the coaxial turbine expander-compressor integrated device.

[0065] The specific steps include: obtaining the historical shaft speed of the Mth rotation in the historical speed data, and its corresponding shaft balance power; using the difference between the shaft balance power of the Mth simulation training and the shaft balance power corresponding to the historical shaft speed of the Mth rotation in the historical speed data to determine the second difference; using the shaft speed output of the M-1th simulation training and the historical shaft speed of the Mth rotation in the historical speed data to make a difference to determine the third difference; and multiplying the third difference by the moment of inertia to obtain the first product; using the third difference divided by the first product to determine the adjustment coefficient of the Mth simulation training. The specific relationship can be satisfied as follows:

[0066]

[0067] Among them, n′ is the historical shaft speed of the coaxial turbine expansion and compression integrated device during the Mth actual operation; f(n′) is the value obtained by the relationship corresponding to the historical shaft speed of the coaxial turbine expansion and compression integrated device during the Mth actual operation; f(n)-f(n′) is the first intermediate value; nn′ is the third difference.

[0068] It should be noted that the total power of the turbo expander B involved in the above formula 2 is e , total power of turbine compressor B c and shaft friction loss power B fThere is no limitation on the method of obtaining , which can be obtained based on the historical values ​​of the actual operation of the coaxial turbine expansion and compression integrated device, or based on the operating parameters under the round.

[0069] For example, the total power of the turbine compressor B is obtained. c The steps may be: determining the inlet enthalpy value, outlet enthalpy value, turbine compressor flow rate and turbine compressor thermal efficiency of the turbine compressor in the Mth simulation training; wherein the inlet enthalpy value, the outlet enthalpy value and the turbine compressor flow rate are obtained by jointly solving the inlet material information, operating parameters and shaft speed output of the turbine compressor in the M-1th simulation training based on the capacity balance mechanism; the turbine compressor thermal efficiency is obtained based on the shaft speed output of the M-1th simulation training and the turbine compressor flow rate in the Mth simulation training; using the difference between the outlet enthalpy value and the inlet enthalpy value of the turbine compressor to obtain a fourth difference value; multiplying the fourth difference value by the turbine compressor flow rate in the Mth simulation training to obtain a first value in the Mth simulation training; determining the turbine compressor power of the turbine compressor by dividing the first value by the turbine compressor thermal efficiency; accumulating the turbine compressor power of the P-stage turbine compressor in the Mth simulation training to obtain the total power of the turbine compressor in the Mth simulation training.

[0070] The specific relationship can be satisfied as follows:

[0071] Among them, H out,i is the outlet enthalpy of the i-th turbine compressor in the M-th simulation training, H in,i is the inlet enthalpy of the i-th turbine compressor in the M-th simulation training, H out,i -H in,i That is the fourth difference of the i-th turbine compressor; F i That is the thermal efficiency of the i-th turbine compressor; Y c,i is the turbine compressor flow rate, i is an integer, and p is the total number of turbine compressor stages.

[0072] For example, the total power of the turboexpander is B eThe steps may be: determining the inlet enthalpy value, outlet enthalpy value, turbine expander flow rate and turbine expander thermal efficiency of the turbine expander in the Mth simulation training; wherein the inlet enthalpy value, the outlet enthalpy value and the turbine expander flow rate are obtained by simultaneously solving the inlet material information, operating parameters and shaft speed output of the turbine expander in the M-1th simulation training based on the capacity balance mechanism; the turbine expander thermal efficiency is obtained based on the shaft speed output of the M-1th simulation training and the turbine expander in the Mth simulation training. The flow rate is obtained; the outlet enthalpy value of the turbine expander is subtracted from the inlet enthalpy value to obtain the fifth difference value of the M-th simulation training; the fifth difference value is divided by the turbine expander flow rate of the M-th simulation training to obtain the second product of the M-th simulation training; the second product is multiplied by the thermal efficiency of the turbine expander to determine the turbine expander power of the turbine expander; the turbine expander powers of the N-stage turbine expanders of the M-th simulation training are accumulated to obtain the total power of the turbine expander of the M-th simulation training.

[0073] The specific relationship can be satisfied as follows:

[0074]

[0075] Among them, H out,i is the outlet enthalpy of the i-th turbine expander in the M-th simulation training, H in,i is the inlet enthalpy of the i-th turbine expander in the M-th simulation training, H out,i -H in,i That is the fifth difference of the i-th turbine expander; F i That is the thermal efficiency of the i-th turbine expander; Y e,i is the flow rate of the turbine expander, and n is the total number of turbine expander stages.

[0076] Shaft friction loss power B f , which is composed of shaft friction loss and static friction starting power. The shaft friction loss is positively correlated with the square of the rotational speed. The greater the shaft speed, the greater the friction. In the zero-speed state (n=0), it is necessary to add a critical torque to overcome the static friction resistance of the solid contact surface, that is, the static friction starting power. Using the shaft friction parameters and the shaft speed output by the M-1 simulation training, combined with the static friction starting power of the given coupling, the shaft friction loss power is obtained. The specific relationship can be expressed as: B f =C V ·n 2 +T S . C V is the shaft friction parameter. S is the static friction starting power.

[0077] The above is a parameter simulation method for a coaxial turbine expansion and compression integrated device provided by the present invention. The above embodiments can be combined according to actual conditions, and the present invention does not make specific limitations here.

[0078] In an exemplary embodiment, please refer to Figure 4 ,like Figure 4 As shown, at the beginning of any simulation round, information about each turboexpander and turbocompressor (i.e., the aforementioned inlet logistics information and operating parameters) can be obtained, and the shaft speed from the previous round can be read. Based on the shaft speed and information from the previous round, the key parameters of each turboexpander and turbocompressor (i.e., turboexpander power) are calculated for each stage. The powers of each turboexpander are summed to obtain the total turboexpander power, and the powers of each turbocompressor are summed to obtain the total turbocompressor power. The shaft power is then calculated by combining the viscous friction loss (i.e., shaft friction loss power) to obtain the shaft speed for the current round.

[0079] In addition, the present invention also provides a parameter simulation system for a coaxial turbine expansion and compression integrated device, comprising a memory, a processor, and a computer program stored on the memory, wherein the processor executes the computer program to implement a parameter simulation method for a coaxial turbine expansion and compression integrated device as described in any one of the above embodiments.

[0080] In the description of the present invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0081] In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connect," "fixed," etc. should be understood broadly. For example, they may refer to fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0082] In the present invention, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0083] In the description of this specification, the terms "one embodiment", "some embodiments", "embodiments", "examples", "specific examples" or "some examples" refer to the specific features, structures, materials or characteristics described in conjunction with the embodiment or example and included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine different embodiments or examples described in this specification and features of different embodiments or examples, unless they are mutually inconsistent.

[0084] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may alter, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A parameter simulation method for a coaxial turbine expansion-compression integrated device, characterized in that: The coaxial turbine expansion and compression integrated device includes connecting an N-stage turbine expander and a P-stage turbine compressor via a coaxial rigid coupling, where N and P are both integers greater than 0, and the method includes:

100. Obtaining the inlet material information and operating parameters of each stage of the turboexpander and each stage of the turbocompressor according to the operator training system VxOTS; wherein the operating parameters include shaft friction parameters associated with the shaft speed; 200. Perform simulation training based on all imported material information, operating parameters, and the shaft speed of the coupling with the specified initial value, and obtain the equipment performance parameters and the shaft speed of the coupling obtained from the simulation training in this round; 300. When it is determined that the equipment performance parameter has not reached the termination condition, the next simulation training is performed. In the Mth simulation training, the shaft speed obtained in the M-1th simulation training is used to calculate the shaft speed of the Mth coupling; the simulation training is performed using the Mth imported material information, the shaft speed, and the operating parameters until the output equipment performance parameter reaches the termination condition; wherein M is an integer greater than 1; 400. The coaxial turbine expansion and compression integrated device obtained through simulation training is used as a device for dynamically simulating performance parameters during operation.

2. The parameter simulation method of the coaxial turbine expansion and compression integrated device according to claim 1, characterized in that: The method further comprises: Obtaining an increase value of the shaft speed of the coupling in the Mth simulation training and the shaft speed output in the M-1th simulation training; Adding the increment value of the Mth simulation training to the shaft speed outputted by the M-1th simulation training to obtain the shaft speed of the Mth simulation training; Among them, the increase value of the shaft speed of the Mth simulation training is obtained based on the total power of the turbine expander, the total power of the turbine compressor, the shaft friction loss power and the preset rotational inertia of the coupling obtained within the set time of the Mth simulation training; the total power of the turbine expander is the Mth total power of all turbine expanders calculated based on the shaft speed output by the M-1th simulation training and the imported material information and operating parameters of the N-stage turbine expander; the total power of the turbine compressor is the Mth total power of all turbine compressors calculated based on the shaft speed output by the M-1th simulation training and the imported material information and operating parameters of the P-stage turbine compressor; the shaft friction loss power is the loss power of the coupling obtained based on the shaft speed output by the M-1th simulation training and the shaft friction parameters.

3. The parameter simulation method of the coaxial turbine expansion and compression integrated device according to claim 2, characterized in that: The step of obtaining the increment value of the shaft speed of the coupling in the Mth simulation training further includes: Obtain the adjustment coefficient of the Mth simulation training; Subtracting the total power of the turboexpander from the total power of the turbocompressor obtained by the M-th simulation training to obtain a first difference; Subtracting the first difference value from the M-th simulation training from the shafting friction loss power to obtain the shaft balancing power from the M-th simulation training; The shaft balance power of the M-th simulation training is divided by the product of the adjustment coefficient and the moment of inertia to determine the increase value of the shaft speed of the coupling of the M-th simulation training.

4. The parameter simulation method of the coaxial turbine expansion and compression integrated device according to claim 3, characterized in that: The obtaining of the adjustment coefficient of the Mth simulation training includes: Obtain the historical shaft speed of the Mth rotation in the historical speed data, and its corresponding shaft balance power; Determine a second difference value by using the difference between the shaft balance power obtained through the M-th simulation training and the shaft balance power corresponding to the historical shaft speed of the M-th rotation in the historical speed data; Determine a third difference by subtracting the shaft speed output from the M-1th simulation training from the historical shaft speed data for the Mth rotation; and divide the second difference by the moment of inertia to obtain a first intermediate value; The adjustment coefficient for the Mth simulation training is determined by dividing the first intermediate value by the third difference.

5. The parameter simulation method of the coaxial turbine expansion and compression integrated device according to claim 3, characterized in that: Before obtaining a first difference value by subtracting the total power of the turboexpander from the total power of the turbocompressor obtained through the M-th simulation training, the method further includes: Determining the inlet enthalpy value, outlet enthalpy value, turbine compressor flow rate, and turbine compressor thermal efficiency of the turbine compressor in the Mth simulation training; wherein the inlet enthalpy value, the outlet enthalpy value, and the turbine compressor flow rate are obtained by simultaneously solving the turbine compressor inlet material information, operating parameters, and shaft speed output from the M-1th simulation training based on a capacity balance mechanism; and the turbine compressor thermal efficiency is obtained based on the shaft speed output from the M-1th simulation training and the turbine compressor flow rate from the Mth simulation training; obtaining a fourth difference value by using a difference between an outlet enthalpy value and an inlet enthalpy value of the turbo compressor; multiplying the fourth difference by the turbine compressor flow rate of the M-th simulation training to obtain a first value of the M-th simulation training; determining a turbo compressor power of the turbo compressor by dividing the first value by the turbo compressor thermal efficiency; The turbine compressor powers of the P-stage turbine compressors of the M-th simulation training are accumulated to obtain the total power of the turbine compressors of the M-th simulation training.

6. The parameter simulation method of the coaxial turbine expansion and compression integrated device according to claim 3, characterized in that: Before obtaining a first difference value by subtracting the total power of the turbine expander obtained by the M-th simulation training from the total power of the turbine expander, the method further includes: Determining the inlet enthalpy value, outlet enthalpy value, turbine expander flow rate, and turbine expander thermal efficiency of the turbine expander in the Mth simulation training; wherein the inlet enthalpy value, the outlet enthalpy value, and the turbine expander flow rate are obtained by simultaneously solving the inlet material information, operating parameters, and shaft speed output from the M-1th simulation training of the turbine expander based on a capacity balance mechanism; and the turbine expander thermal efficiency is obtained based on the shaft speed output from the M-1th simulation training and the turbine expander flow rate from the Mth simulation training; Subtracting the outlet enthalpy value from the inlet enthalpy value of the turboexpander to obtain a fifth difference value of the M-th simulation training; Dividing the fifth difference by the turbine expander flow rate of the M-th simulation training to obtain a second product of the M-th simulation training; multiplying the turboexpander thermal efficiency by the second product to determine a turboexpander power of the turboexpander; The turbine expander powers of the N-stage turbine expanders in the M-th simulation training are accumulated to obtain the total power of the turbine expander in the M-th simulation training.

7. The parameter simulation method of the coaxial turbine expansion and compression integrated device according to claim 3, characterized in that: Before obtaining the shaft balance power of the Mth simulation training by subtracting the first difference value of the Mth simulation training from the shaft system friction loss power, the method further includes: The shafting friction loss power is obtained by utilizing the shafting friction parameter and the shaft speed output from the M-1th simulation training, combined with a given static friction starting power of the coupling.

8. The parameter simulation method of the coaxial turbine expansion and compression integrated device according to claim 1, characterized in that: The method further comprises: The coaxial turbine expansion and compression integrated device that meets the termination conditions is used to perform simulation prediction based on the inlet material information of each stage of the turbine expander and turbine compressor to obtain the outlet material information of each stage of the turbine expander and turbine compressor.

9. The parameter simulation method of the coaxial turbine expansion and compression integrated device according to claim 1, characterized in that: The operating parameters also include at least one of the following: moment of inertia, maximum acceleration rate, maximum deceleration rate; the import logistics information includes at least one of the following: temperature, pressure, flow rate, and component.

10. A parameter simulation system for a coaxial turbine expansion-compression integrated device, comprising a memory, a processor, and a computer program stored in the memory, characterized in that: The processor executes the computer program to implement the parameter simulation method of the coaxial turbine expansion and compression integrated device as described in any one of claims 1 to 9.

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