Optimization design method for fuel cell centrifugal air compressor based on advanced computational fluid dynamics analysis

Abstract

The application discloses a kind of fuel cell centrifugal air compressor optimization design methods based on advanced analysis, first build centrifugal air compressor performance test platform, then test to a certain centrifugal air compressor, establish its numerical calculation model and simulation, then the test value and simulation value of performance parameter are compared and analyzed;After verification, the analysis model and advanced analysis model of the centrifugal air compressor are established;Finally, the structural parameters of centrifugal air compressor are modified, the numerical calculation model of centrifugal air compressor with different structural parameters is established and simulated;Then the analysis model and advanced analysis model of different structural parameters are established, to reduce loss and improve efficiency as target, the structural parameters are iteratively optimized, until the structural parameters of centrifugal air compressor that meet minimum loss and maximum efficiency are obtained simultaneously.The application starts from the angle of energy loss, and realizes the high-efficiency and low-loss optimization of centrifugal air compressor by using advanced analysis.

Description

Technical Field

[0001] The present invention relates to the field of fuel cells, in particular to a fuel cell based on advanced Analyzed optimization design method of fuel cell centrifugal air compressor. Background Art

[0002] Fuel cells are devices that convert chemical energy directly into electrical energy. They offer advantages such as high efficiency, cleanliness, and environmental friendliness, and are widely used in transportation, energy stations, and mobile power sources. In fuel cell systems, air compressors play a key role, providing gas supply and pressurization.

[0003] Engineering Thermodynamics The concept of (exergy) provides a method to quantify energy losses, which is based on the second law of thermodynamics and is used to evaluate irreversible losses in energy conversion processes. Analysis can determine the size and location of energy losses, thus providing a basis for improving system design and operation. Analysis of advanced Analysis can pinpoint the contribution of specific components to system performance, thereby identifying avoidable and mitigable risks. The structure of the loss is optimized to improve the system performance.

[0004] Others for advanced The application of the analytical method has also been verified. In the book "Optimization of Heating Units by Analytical Method", advanced The analysis method was used to optimize the heating unit and the improvement order of the heating unit was obtained, which shows that the advanced The analytical method can effectively combine the design of specific components and provide a practical and feasible solution for the improvement of heating units.

[0005] But currently for advanced The application of analytical methods is mainly focused on the components of the system, but not on the specific optimization parts of a component. The analyzed fuel cell air compressor optimization method has great research potential. Summary of the Invention

[0006] In view of the shortcomings of the prior art, the present invention aims to provide a Analyzed optimization design method of fuel cell centrifugal air compressor.

[0007] The technical solution of the present invention to solve the technical problem is to provide a The optimized design method of the centrifugal air compressor for fuel cells analyzed is characterized in that the method comprises the following steps:

[0008] Step 1: Design and build a fuel cell centrifugal air compressor performance test platform;

[0009] Step 2: Place a centrifugal air compressor on the test platform of step 1 to conduct a test to obtain test values ​​of performance parameters of the centrifugal air compressor;

[0010] Step 3: According to the centrifugal air compressor of step 2, the structural parameters of the centrifugal air compressor are obtained, and then a numerical calculation model of the centrifugal air compressor is established according to the structural parameters;

[0011] Step 4: Perform simulation on the numerical calculation model obtained in step 3 to obtain simulation values ​​of the performance parameters of the centrifugal air compressor;

[0012] Step 5: Compare and analyze the test value of the performance parameter obtained in step 2 with the simulation value of the performance parameter obtained in step 4; if the maximum fitting error between the pressure ratio in the test value of the performance parameter obtained in step 2 and the pressure ratio in the simulation value of the performance parameter obtained in step 4 is ≤10%, proceed to step 6; if the maximum fitting error between the pressure ratio in the test value of the performance parameter obtained in step 2 and the pressure ratio in the simulation value of the performance parameter obtained in step 4 is greater than 10%, return to step 3;

[0013] Step 6: Post-process the numerical calculation model of the centrifugal air compressor obtained in step 3 to obtain the field quantity data of the centrifugal air compressor; then calculate the Value, get the centrifugal air compressor Analytical models;

[0014] Step 7: The centrifugal air compressor obtained in step 6 Analyze the analysis model and then expand the analysis results. Internal avoidable losses Loss E EN,AV Internal inevitable Loss E EN,UN , external avoidable Loss E EX,AV and external inevitable Loss E EX,UN , and then establish the advanced Analyze the model; then Analyze the model and get the optimized Losses are internally avoidable Loss E EN,AV and quantify it;

[0015] Step 8: Modify the structural parameters of the centrifugal air compressor. According to step 3, establish the numerical calculation model of the centrifugal air compressor with different structural parameters. Then, according to step 4, calculate the simulation values ​​of the performance parameters of the centrifugal air compressor with different structural parameters. Then, according to step 6, establish the numerical calculation model of the centrifugal air compressor with different structural parameters. Analyze the model; then follow step 7 to establish the advanced model of centrifugal air compressor with different structural parameters. Analyze the model and study the effects of different structural parameters on the internal avoidable Loss E EN,AV The influence of the law, find out the internal avoidable Loss E EN,AV The structural parameters with influence are then iteratively optimized until the minimum Structural parameters of centrifugal air compressor with loss and maximum efficiency.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] (1) The present invention first builds a centrifugal air compressor performance test platform, then carries a centrifugal air compressor on the test platform for testing, then establishes a numerical calculation model of the centrifugal air compressor and performs simulation, and then compares and analyzes the test values ​​of the performance parameters with the simulation values ​​of the performance parameters; after verification, the centrifugal air compressor is established. Analyze the model and build advanced Analyze the model; finally, modify the structural parameters of the centrifugal air compressor, establish a numerical calculation model of the centrifugal air compressor with different structural parameters and simulate it to obtain the simulation values ​​of the performance parameters with different structural parameters; then establish the numerical calculation model of the centrifugal air compressor with different structural parameters Analytical models and advanced Analyze the model to reduce The purpose of this study is to study the structural parameters and The correlation between the losses; then the structural parameters are iteratively optimized until the minimum Structural parameters of centrifugal air compressor with loss and maximum efficiency.

[0018] (2) From the perspective of energy loss, the present invention adopts advanced The analysis method is used to study the irreversible loss mechanism of the complex flow and heat transfer process of the centrifugal air compressor, aiming to improve the efficiency of the air compressor while reducing Loss, to achieve high-efficiency and low-loss optimization of centrifugal air compressors, reduce energy loss, and provide new ideas for the optimal design of centrifugal air compressor air ducts and aerodynamic performance from the perspective of energy quality. At the same time, it provides a theoretical basis for the structural optimization of mechanical equipment such as fans and turbines involving complex working fluid flows, which has important scientific significance and application value.

[0019] (3) The application can accurately indicate the contribution of a specific component to the system performance, thereby obtaining a structure that can avoid losses, and can realize the optimal design of the structure while improving the efficiency of the air compressor and reducing energy loss.

[0020] (4) The fuel cell centrifugal air compressor performance test platform built by the application considers the cooling system and the data processing system, can automatically collect data and upload them to the host computer, and can control the throttle opening degree through the host computer. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 is the overall flowchart of the application;

[0022] Figure 2 is a structural schematic diagram of the fuel cell centrifugal air compressor performance test platform of the application;

[0023] Figure 3 is a pressure ratio-mass flow characteristic curve diagram in the test results of the two-stage centrifugal air compressor of Example 1 of the application;

[0024] Figure 4 is a geometric entity model schematic diagram of the two-stage centrifugal air compressor of Example 1 of the application;

[0025] Figure 5 is a grid model schematic diagram of the two-stage centrifugal air compressor after grid division of Example 1 of the application;

[0026] Figure 6 is a schematic diagram of the impeller structure of the two-stage centrifugal air compressor obtained by the optimal design of Example 1 of the application.

[0027] In the figure, the air filter 1, the air flow meter at the inlet end 2, the temperature and pressure integrated sensor at the inlet end 3, the centrifugal air compressor 4, the temperature and pressure integrated sensor at the outlet end 5, the intercooler 6, the air flow / temperature meter at the outlet end 7, the throttle valve 8, the first water tank 9, the first water pump 10, the waterway regulating valve 11, the electromagnetic flow meter 12, the temperature and pressure integrated sensor in front of the controller 13, the controller 14, the temperature and pressure integrated sensor behind the controller 15, the temperature and pressure integrated sensor behind the air compressor 16, the first radiator 17, the second water tank 18, the second water pump 19, the second radiator 20, and the host computer 21. DETAILED DESCRIPTION

[0028] The application provides a fuel cell centrifugal air compressor optimal design method based on advanced analysis (referred to as the method), which is characterized by comprising the following steps:

[0029] ​Step 1, design and build a fuel cell centrifugal air compressor performance test platform (referred to as test platform, as shown in Figure 2

[0030] Preferably, in step 1, the test platform comprises an air filter 1, an air inlet flowmeter 2, an air inlet temperature and pressure integrated sensor 3, an air outlet temperature and pressure integrated sensor 5, an air outlet air flow / temperature meter 7, a throttle valve 8, a controller 14, an upper computer 21, a first water cooling system and a second water cooling system.

[0031] The first water cooling system is used to cool the high-power components of the controller 14 and the centrifugal air compressor 4, and comprises a first water tank 9, a first water pump 10, a waterway regulating valve 11, an electromagnetic flowmeter 12, a controller front-end temperature and pressure integrated sensor 13, a controller rear-end temperature and pressure integrated sensor 15, an air compressor rear-end temperature and pressure integrated sensor 16 and a first radiator 17.

[0032] The second water cooling system is used to cool the compressed gas of the centrifugal air compressor 4, and comprises a intercooler 6, a second water tank 18, a second water pump 19 and a second radiator 20.

[0033] The outlet of the air filter 1 is in communication with the inlet of the air inlet flowmeter 2; the outlet of the air inlet flowmeter 2 is in communication with the air inlet of the centrifugal air compressor 4 through a pipeline, and the pipeline is provided with the air inlet temperature and pressure integrated sensor 3; the air outlet of the centrifugal air compressor 4 is in communication with the gas inlet of the intercooler 6 through a pipeline, and the pipeline is provided with the air outlet temperature and pressure integrated sensor 5; the gas outlet of the intercooler 6 is in communication with the inlet of the air outlet air flow / temperature meter 7; the outlet of the air outlet air flow / temperature meter 7 is in communication with the outside through the throttle valve 8.

[0034] The air filter 1 is used to filter the air entering the centrifugal air compressor 4; the air inlet flowmeter 2 is used to measure the flow of the gas at the air inlet of the centrifugal air compressor 4; the air inlet temperature and pressure integrated sensor 3 is used to monitor the temperature and pressure of the gas at the air inlet of the centrifugal air compressor 4; the air outlet temperature and pressure integrated sensor 5 is used to monitor the temperature and pressure of the gas at the air outlet of the centrifugal air compressor 4 (i.e. the compressed gas of the centrifugal air compressor 4); the intercooler 6 is used to cool the compressed gas of the centrifugal air compressor 4; the air outlet air flow / temperature meter 7 is used to measure the temperature and flow of the gas cooled by the intercooler 6; the throttle valve 8 is used to adjust the flow of the gas discharged by the centrifugal air compressor 4.

[0035] ​The water outlet of the first water tank 9 is connected to the inlet of the first water pump 10; the outlet of the first water pump 10 is connected to the inlet of the electromagnetic flowmeter 12 through a pipeline, and a water regulating valve 11 is provided on the pipeline; the outlet of the electromagnetic flowmeter 12 is connected to the cooling system inlet of the controller 14 through a pipeline, and a temperature-pressure integrated sensor 13 at the front end of the controller is provided on the pipeline; the cooling system outlet of the controller 14 is connected to the cooling system inlet of the centrifugal air compressor 4 through a pipeline, and a temperature-pressure integrated sensor 15 at the rear end of the controller is provided on the pipeline; the cooling system outlet of the centrifugal air compressor 4 is connected to the inlet of the first radiator 17 through a pipeline, and a temperature-pressure integrated sensor 16 at the rear end of the air compressor is provided on the pipeline; the outlet of the first radiator 17 is connected to the water inlet of the first water tank 9;

[0036] The water-circuit regulating valve 11 is used to regulate the flow of cooling water in the first water-cooling system; the electromagnetic flowmeter 12 is used to measure the flow of cooling water before the cooling controller 14; the temperature-pressure integrated sensor 13 at the front end of the controller is used to monitor the temperature and pressure of the cooling water before the cooling controller 14; the temperature-pressure integrated sensor 15 at the rear end of the controller is used to monitor the temperature and pressure of the cooling water after the cooling controller 14; the temperature-pressure integrated sensor 16 at the rear end of the air compressor is used to monitor the temperature and pressure of the cooling water after the cooling centrifugal air compressor 4; the first radiator 17 is used to further cool the cooling water;

[0037] The water outlet of the intercooler 6 is connected to the inlet of the second radiator 20; the outlet of the second radiator 20 is connected to the water inlet of the second water tank 18; the water outlet of the second water tank 18 is connected to the inlet of the second water pump 19; the outlet of the second water pump 19 is connected to the water inlet of the intercooler 6; the second water pump 19 delivers cooling water to the intercooler 6 to cool the gas compressed by the centrifugal air compressor 4, and the cooling water is then cooled by the second radiator 20 and flows back to the second water tank 18;

[0038] The host computer 21 is respectively connected to the intake air flow meter 2, the intake temperature and pressure integrated sensor 3, the exhaust temperature and pressure integrated sensor 5, the exhaust air flow / temperature meter 7, the throttle 8, the first water pump 10, the water channel regulating valve 11, the electromagnetic flow meter 12, the controller front-end temperature and pressure integrated sensor 13, the controller rear-end temperature and pressure integrated sensor 15, the air compressor rear-end temperature and pressure integrated sensor 16 and the second water pump 19 through the controller 14.

[0039] Preferably, in step 1, the operation interface of the host computer 21 can set the temperature of the gas at the exhaust end of the centrifugal air compressor 4, the temperature of the cooling water in the first water cooling system, the PWM pulse width of the first water pump 10, the PWM pulse width of the second water pump 19, the opening degree of the throttle valve 8, and the opening degree of the waterway regulating valve 11; the operation interface can display the flow rate and temperature and pressure of the gas at the intake end of the centrifugal air compressor 4, the temperature and pressure of the gas at the exhaust end of the centrifugal air compressor 4, the temperature and flow rate of the gas cooled by the intercooler 6, the opening degree of the throttle valve 8, the temperature of the controller 14, the rotational speed of the first water pump 10, the opening degree of the waterway regulating valve 11, the flow rate and temperature and pressure of the cooling water before the cooling controller 14, the temperature and pressure of the cooling water after the cooling controller 14, the temperature and pressure of the cooling water after cooling the centrifugal air compressor 4, and the rotational speed of the second water pump 19.

[0040] Preferably, in step 1, the host computer 21 acquires in real time, through the controller 14, the flow rate of the gas at the intake end of the centrifugal air compressor 4 collected by the intake end air flow meter 2, the temperature and pressure of the gas at the intake end of the centrifugal air compressor 4 collected by the intake end temperature and pressure integrated sensor 3, the temperature and pressure of the gas at the exhaust end of the centrifugal air compressor 4 collected by the exhaust end temperature and pressure integrated sensor 5, the temperature and flow rate of the gas cooled by the intercooler 6 collected by the exhaust end air flow / temperature meter 7, the opening degree of the throttle valve 8, the temperature of the controller 14, the rotational speed of the first water pump 10, the opening degree of the waterway regulating valve 11, the flow rate of the cooling water before the cooling controller 14 collected by the electromagnetic flow meter 12, the temperature and pressure of the cooling water before the cooling controller 14 collected by the controller front end temperature and pressure integrated sensor 13, the temperature and pressure of the cooling water after the cooling controller 14 collected by the controller rear end temperature and pressure integrated sensor 15, the temperature and pressure of the cooling water after cooling the centrifugal air compressor 4 collected by the air compressor rear end temperature and pressure integrated sensor 16, and the rotational speed of the second water pump 19.

[0041] Preferably, in step 1, the host computer 21 controls the rotational speed of the first water pump 10 by controlling the PWM pulse width of the first water pump 10 through the controller 14, and controls the flow rate of the cooling water in the first water cooling system by controlling the opening degree of the waterway regulating valve 11 through the controller 14, so that the flow rate of the cooling water is maintained within a reasonable range and does not exceed the set value, and the temperature of the cooling water in the first water cooling system is maintained within a reasonable range and does not exceed the set value by controlling the first radiator 17.

[0042] Preferably, in step 1, the host computer 21 controls the PWM pulse width of the second water pump 19 through the controller 14 to control the speed of the second water pump 19 to regulate the flow of cooling water in the second water cooling system, so that the flow of cooling water is maintained within a reasonable range and does not exceed the set value, and the cooling water flow cooperates with the second radiator 20 to control the temperature of the cooling water in the second water cooling system to be maintained within a reasonable range and does not exceed the set value; the host computer 21 controls the opening of the throttle valve 8 through the controller 14 to regulate the flow of the exhaust end gas of the centrifugal air compressor 4 to be maintained within a reasonable range; the temperature of the cooling water cooperates with the opening of the throttle valve 8 to regulate the temperature of the gas after cooling by the intercooler 6 to be maintained within a reasonable range and does not exceed the set value.

[0043] Step 2: Place a centrifugal air compressor on the test platform of step 1 to conduct a test to obtain test values ​​of performance parameters of the centrifugal air compressor;

[0044] Preferably, in step 2, the performance parameters include speed, throttle opening, mass flow, temperature, pressure and pressure ratio. The ratio of the pressure at the exhaust end of the centrifugal air compressor 4 to the pressure at the intake end is the pressure ratio of the centrifugal air compressor 4. The speed of the centrifugal air compressor 4 and the opening of the throttle 8 are directly adjusted by the host computer 21. The opening of the throttle 8 directly affects the mass flow of the centrifugal air compressor 4.

[0045] Step 3: According to the centrifugal air compressor of step 2, the structural parameters of the centrifugal air compressor are obtained, and then a numerical calculation model of the centrifugal air compressor is established according to the structural parameters;

[0046] Preferably, step 3 specifically comprises: first establishing a geometric entity model of the centrifugal air compressor through three-dimensional modeling software according to the structural parameters of the centrifugal air compressor in step 2, then meshing the geometric entity model of the centrifugal air compressor and dividing it into discrete small units for numerical calculation; then setting the solver and boundary conditions in the CFD software to obtain the numerical calculation model of the centrifugal air compressor.

[0047] Preferably, in step 3, the structural parameters include the geometric shapes of the impeller, diffuser, inlet and outlet ducts and volute, the number of blades, the inlet and outlet angles of the diffuser, whether the diffuser has blades or not, the size of the impeller blade tip clearance and the impeller inlet and outlet installation angles.

[0048] Preferably, in step 3, the geometric entity model includes an impeller, an inlet and outlet ducts, a volute and a diffuser.

[0049] Preferably, in step 3, the solver uses the finite volume method to consider the movement of the fluid and heat conduction.

[0050] Preferably, in step 3, the boundary conditions include: setting the inlet as a pressure inlet, setting the outlet as a mass flow outlet, monitoring the inlet flow, and using the inlet and outlet flow difference as a criterion for determining the convergence of the simulation.

[0051] Step 4: Simulate the numerical calculation model obtained in step 3 using CFD software to obtain simulation values ​​of the performance parameters of the centrifugal air compressor;

[0052] Step 5: Compare and analyze the test values ​​of the performance parameters obtained in step 2 with the simulation values ​​of the performance parameters obtained in step 4 to verify the accuracy and reliability of the numerical calculation model of the centrifugal air compressor obtained in step 3;

[0053] If the maximum fitting error between the pressure ratio in the test value of the performance parameter obtained in step 2 and the pressure ratio in the simulation value of the performance parameter obtained in step 4 is ≤10%, proceed to step 6; if the maximum fitting error between the pressure ratio in the test value of the performance parameter obtained in step 2 and the pressure ratio in the simulation value of the performance parameter obtained in step 4 is greater than 10%, return to step 3;

[0054] Preferably, in step 5, the maximum fitting error is the absolute value of the difference between the pressure ratio test value and the pressure ratio simulation value divided by the pressure ratio test value.

[0055] Preferably, in step 5, if the maximum fitting error between the pressure ratio in the test value of the performance parameter obtained in step 2 and the pressure ratio in the simulation value of the performance parameter obtained in step 4 is greater than 10%, return to step 3 and start again from the meshing of step 3.

[0056] Step 6: Use CFD-Post to post-process the numerical calculation model of the centrifugal air compressor obtained in step 3 to obtain the field quantity data of the centrifugal air compressor; then calculate the Value, get the centrifugal air compressor Analyze the model for more intuitive understanding and analysis The spatial distribution characteristics of the losses;

[0057] Preferably, in step 6, the field quantity data include temperature, specific enthalpy h and specific entropy s;

[0058] Preferably, in step 6, the field quantity data is calculated The specific value is: According to thermodynamics theory, the value of each node in the system is The value is calculated by formula (1):

[0059] E=m[(h-h0)-T0(s-s0)] (1)

[0061] In formula (1), m is the mass flow rate of the node (kg / s); h is the specific enthalpy (kJ / kg); s is the specific entropy (kJ / kg·K); T0 is the thermodynamic temperature of the environment (K); and the subscript 0 indicates the state of the environment.

[0062] Step 7: The centrifugal air compressor obtained in step 6 Analyze the analysis model and then expand the analysis results. Internal avoidable losses Loss E EN,AV Internal inevitable Loss E EN,UN , external avoidable Loss E EX,AV and external inevitable Loss E EX,UN , and then establish the advanced Analytical model; then use engineering analysis method to Analyze the model to study the internal structure of the centrifugal air compressor Loss E EN The distribution pattern of The degree of loss and energy consumption contribution are used to obtain the optimizable Losses are internally avoidable Loss E EN,AV and quantify it;

[0063] Preferably, in step 7, the centrifugal air compressor obtained in step 6 is treated by a thermal cycle method. The analytical model was analyzed and the Analysis model There are two ways to classify loss E:

[0064] E=E AV +E UN

[0065] E=E EN +E EX (2)

[0066] In formula (2), E AV To avoid Losses, that is, losses that can be reduced through technical optimization and structural adjustment Loss is the part that can be controlled in system design and operation; E UN For the inevitable Losses represent those losses that cannot be eliminated even with the most advanced technology and without considering the cost. They are inherent in the system and are closely related to the physical characteristics and working conditions of the components; E EN For internal Loss, which describes the irreversible process caused by the internal components or parts Loss; E EX For external Losses, which involve external influences on specific components or parts caused by other parts of the system;

[0067] Preferably, in step 7, the expansion is to combine the two classification methods of formula (2) to obtain a more detailed The classification of loss E is shown in formula (3):

[0068] E=E EN,AV +E EN,UN +E EX,AV +E EX,UN (3)

[0069] In formula (3), E EN,AV Avoidable internal This loss can be avoided by optimizing the structural parameters of the component or part. Loss is also the main direction for optimizing and improving system performance; E EN,UN Inevitable for internal Loss is an irreversible loss inherent in the component and cannot be avoided even if the component works under optimal conditions; E EX,AV Externally avoidable Losses can be reduced by optimizing the structural parameters of other components or parts in the system Loss; E EX,UN Unavoidable external Losses that cannot be reduced even if other components or parts in the system work at optimal conditions loss.

[0070] Preferably, in step 7, quantification is to avoid the internal Loss E EN,AV Quantified as irreversible heat transfer, adiabatic throttling, fluid mixing and external leakage.

[0071] Step 8: Modify the structural parameters of the centrifugal air compressor. According to step 3, establish the numerical calculation model of the centrifugal air compressor with different structural parameters. Then, according to step 4, calculate the simulation values ​​of the performance parameters of the centrifugal air compressor with different structural parameters. Then, according to step 6, establish the numerical calculation model of the centrifugal air compressor with different structural parameters. Analyze the model; then follow step 7 to establish the advanced model of centrifugal air compressor with different structural parameters. Analyze the model and study the effects of different structural parameters on the internal avoidable Loss E EN,AV The influence of the law, find out the internal avoidable Loss E EN,AV The structural parameters that have an impact; then the multi-objective optimization algorithm is used for the structural parameters that have an impact, and the optimization objective is to consider the minimum The two competing goals of loss and maximum efficiency are optimized iteratively until the minimum loss and maximum efficiency are achieved. Structural parameters of centrifugal air compressor with loss and maximum efficiency.

[0072] Preferably, the method further comprises the steps of:

[0073] Step 9: Follow the steps in step 8 to meet the minimum The numerical calculation model corresponding to the structural parameters of the centrifugal air compressor with loss and maximum efficiency is used to manufacture the corresponding centrifugal air compressor;

[0074] Step 10: According to the method of step 2, the centrifugal air compressor obtained in step 9 is placed on the test platform of step 1 for testing to obtain test values ​​of performance parameters of the centrifugal air compressor;

[0075] Step 11: Calculate the efficiency of the centrifugal air compressor based on the test values ​​of the performance parameters of the centrifugal air compressor obtained in step 10 to obtain the calculated value of the efficiency; if the error between the calculated value of the efficiency and the maximum efficiency obtained in step 8 is ≤10%, the optimization is completed; if the error is greater than 10%, return to step 8 and re-optimize to obtain a new value that satisfies the minimum efficiency. Structural parameters of centrifugal air compressor with loss and maximum efficiency.

[0076] Preferably, in step 11 , the error is the absolute value of the difference between the calculated efficiency and the maximum efficiency in step 8 divided by the maximum efficiency in step 8 .

[0077] Example 1

[0078] In step 2, the test object is a fuel cell two-stage centrifugal air compressor.

[0079] The air compressor speed is directly adjusted by the host computer 21, gradually increasing from 20000rpm to 90000rpm at intervals of 10000rpm; at the same time, the throttle opening is adjusted to adjust the mass flow rate when the speed is stable at different speeds, and the inlet and outlet pressures and temperatures at each speed and mass flow rate are recorded respectively. The data are collected by the inlet and outlet temperature and pressure integrated sensors and uploaded to the host computer 21; the data collected by the host computer 21 are processed to obtain the test values ​​of the performance parameters of the centrifugal air compressor, such as Figure 3 As shown, Figure 3 The figure shows the pressure ratio-mass flow characteristic curve from the test results of a two-stage centrifugal air compressor;

[0080] In step 3, the numerical calculation model of the centrifugal air compressor is established as follows: according to the structural parameters of the centrifugal air compressor in step 2, a geometric solid model of the centrifugal air compressor is first established by a three-dimensional modeling software, and then the geometric solid model of the centrifugal air compressor is meshed (such asFigure 5 (as shown), dividing it into discrete small units; then setting the solver and boundary conditions in the CFD software to obtain the numerical calculation model of the centrifugal air compressor;

[0081] The geometric entity model includes the low-pressure end air inlet, the high-pressure end air outlet, the two-stage impeller, the air inlet and outlet pipes, the volute, the diffuser and the pipes between the high and low pressure machines, such as Figure 4 As shown;

[0082] Boundary conditions include: atmospheric conditions at the low-pressure stage compressor inlet and room temperature (298K); mass flow at the high-pressure stage compressor outlet. When analyzing the high-pressure stage alone, the high-pressure compressor inlet pressure is set to the average total pressure at the low-pressure stage compressor outlet, and the temperature is set to the average total temperature at the low-pressure stage compressor outlet. The outlet mass flow rate is set to ensure consistent mass flow between the high-pressure and low-pressure stages. Adiabatic no-slip boundaries are set for the solid walls, and the corresponding rotational speeds of the rotor blades and hub are set. The remaining walls are stationary.

[0083] In step 5, Table 1 compares the pressure ratio characteristics of the two-stage centrifugal air compressor of Example 1 at 80,000 rpm, comparing the simulation results with the experimental results. The data are the pressure ratios at a speed of 80,000 rpm for mass flow rates of 0.06 kg / s, 0.075 kg / s, 0.09 kg / s, 0.105 kg / s, 0.12 kg / s, 0.135 kg / s, and 0.15 kg / s, respectively. As can be seen from Table 1, the maximum fitting error between the simulation and experimental values ​​is less than 8.85%, verifying the accuracy and reliability of the numerical calculation model for the centrifugal air compressor obtained in step 3.

[0084] Table 1

[0085]

[0086] In step 7, quantizing the interior can avoid Loss E EN,AV , the specific calculated values ​​of irreversible heat transfer, adiabatic throttling, fluid mixing, and external leakage of the two-stage centrifugal air compressor at 80000rpm and 0.105kg / s are obtained, as shown in Table 2;

[0087] Table 2

[0088]

[0089] In step 8, the minimum The impeller structure of a two-stage centrifugal air compressor with loss and maximum efficiency is as follows Figure 6 As shown in the figure, the numerical analysis was performed using CFD software, and the simulation results showed that the high-pressure end air compressor was at 80000rpm and 0.105kg / s. Energy loss, as shown in Table 3. As can be seen from Table 3, the use of advanced After the analysis, the efficiency and pressure ratio of the air compressor impeller and high-pressure air compressor were improved to a certain extent, with the efficiency increased by 2.08% and the pressure ratio increased by 1.82%.

[0090] Table 3

[0091]

[0092] #imgpt94#

[0093] Any matters not described in the present invention are applicable to the prior art.

Claims

1. Based on advanced The optimized design method of the fuel cell centrifugal air compressor analyzed is characterized in that: The method comprises the following steps: Step 1: Design and build a fuel cell centrifugal air compressor performance test platform; Step 2: Place a centrifugal air compressor on the test platform of step 1 to conduct a test to obtain test values ​​of performance parameters of the centrifugal air compressor; Step 3: According to the centrifugal air compressor of step 2, the structural parameters of the centrifugal air compressor are obtained, and then a numerical calculation model of the centrifugal air compressor is established according to the structural parameters; Step 4: Perform simulation on the numerical calculation model obtained in step 3 to obtain simulation values ​​of the performance parameters of the centrifugal air compressor; Step 5: Compare and analyze the test value of the performance parameter obtained in step 2 with the simulation value of the performance parameter obtained in step 4; if the maximum fitting error between the pressure ratio in the test value of the performance parameter obtained in step 2 and the pressure ratio in the simulation value of the performance parameter obtained in step 4 is ≤10%, proceed to step 6; if the maximum fitting error between the pressure ratio in the test value of the performance parameter obtained in step 2 and the pressure ratio in the simulation value of the performance parameter obtained in step 4 is greater than 10%, return to step 3; Step 6: Post-process the numerical calculation model of the centrifugal air compressor obtained in step 3 to obtain the field quantity data of the centrifugal air compressor; then calculate the Value, get the centrifugal air compressor Analytical models; Step 7: The centrifugal air compressor obtained in step 6 Analyze the analysis model and then expand the analysis results. Internal avoidable losses Loss E EN,AV Internal inevitable Loss E EN,UN , external avoidable Loss E EX,AV and external inevitable Loss E EX,UN , and then establish the advanced Analyze the model; then Analyze the model and get the optimized Losses are internally avoidable Loss E EN,AV and quantify it; Step 8: Modify the structural parameters of the centrifugal air compressor. According to step 3, establish the numerical calculation model of the centrifugal air compressor with different structural parameters. Then, according to step 4, calculate the simulation values ​​of the performance parameters of the centrifugal air compressor with different structural parameters. Then, according to step 6, establish the numerical calculation model of the centrifugal air compressor with different structural parameters. Analyze the model; then follow step 7 to establish the advanced model of centrifugal air compressor with different structural parameters. Analyze the model and study the effects of different structural parameters on the internal avoidable Loss E EN,AV The influence of the law, find out the internal avoidable Loss E EN,AV The structural parameters with influence are then iteratively optimized until the minimum Structural parameters of centrifugal air compressor with loss and maximum efficiency.

2. According to claim 1, based on advanced The optimized design method of the fuel cell centrifugal air compressor analyzed is characterized in that: In step 1, the test platform includes an air filter (1), an air flow meter at the intake end (2), an integrated temperature and pressure sensor at the intake end (3), an integrated temperature and pressure sensor at the exhaust end (5), an air flow / temperature meter at the exhaust end (7), a throttle valve (8), a controller (14), a host computer (21), a first water cooling system, and a second water cooling system; The first water cooling system is used to cool the controller (14) and the air compressor (4), and includes a first water tank (9), a first water pump (10), a waterway regulating valve (11), an electromagnetic flowmeter (12), a controller front-end temperature-pressure integrated sensor (13), a controller rear-end temperature-pressure integrated sensor (15), an air compressor rear-end temperature-pressure integrated sensor (16), and a first radiator (17); The second water cooling system is used to cool the gas compressed by the air compressor (4), and includes an intercooler (6), a second water tank (18), a second water pump (19) and a second radiator (20); The outlet of the air filter (1) is connected to the inlet of the air flow meter (2) at the air intake end; the outlet of the air flow meter (2) at the air intake end is connected to the air intake of the air compressor (4) through a pipeline, and an air intake end temperature and pressure integrated sensor (3) is provided on the pipeline; the exhaust port of the air compressor (4) is connected to the air path inlet of the intercooler (6) through a pipeline, and an exhaust end temperature and pressure integrated sensor (5) is provided on the pipeline; the air path outlet of the intercooler (6) is connected to the inlet of the exhaust end air flow / temperature meter (7); the outlet of the exhaust end air flow / temperature meter (7) is connected to the outside world through a throttle valve (8); The water outlet of the first water tank (9) is connected to the inlet of the first water pump (10); the outlet of the first water pump (10) is connected to the inlet of the electromagnetic flowmeter (12) through a pipeline, and a water regulating valve (11) is provided on the pipeline; the outlet of the electromagnetic flowmeter (12) is connected to the cooling system inlet of the controller (14) through a pipeline, and a controller front-end temperature and pressure integrated sensor (13) is provided on the pipeline; the cooling system outlet of the controller (14) is connected to the cooling system inlet of the air compressor (4) through a pipeline, and a controller rear-end temperature and pressure integrated sensor (15) is provided on the pipeline; the cooling system outlet of the air compressor (4) is connected to the inlet of the first radiator (17) through a pipeline, and an air compressor rear-end temperature and pressure integrated sensor (16) is provided on the pipeline; the outlet of the first radiator (17) is connected to the water inlet of the first water tank (9); The water outlet of the intercooler (6) is communicated with the inlet of the second radiator (20); the outlet of the second radiator (20) is communicated with the water inlet of the second water tank (18); the water outlet of the second water tank (18) is communicated with the inlet of the second water pump (19); the outlet of the second water pump (19) is communicated with the water inlet of the intercooler (6); The host computer (21) is respectively connected to the air flow meter (2) at the intake end, the temperature and pressure integrated sensor (3) at the intake end, the temperature and pressure integrated sensor (5) at the exhaust end, the air flow / temperature meter (7) at the exhaust end, the throttle valve (8), the first water pump (10), the waterway regulating valve (11), the electromagnetic flow meter (12), the temperature and pressure integrated sensor (13) at the front end of the controller, the temperature and pressure integrated sensor (15) at the rear end of the controller, the temperature and pressure integrated sensor (16) at the rear end of the air compressor, and the second water pump (19) through the controller (14).

3. According to claim 2, based on advanced The optimized design method of the fuel cell centrifugal air compressor analyzed is characterized in that: In step 1, the operation interface of the host computer (21) can set the temperature of the exhaust end gas of the air compressor (4), the temperature of the cooling water in the first water cooling system, the PWM pulse width of the first water pump (10), the PWM pulse width of the second water pump (19), the opening of the throttle valve (8), and the opening of the water circuit regulating valve (11); the operation interface can display the flow rate, temperature, and pressure of the intake end gas of the air compressor (4), the temperature and pressure of the exhaust end gas of the air compressor (4), the temperature and flow rate of the gas cooled by the intercooler (6), the opening of the throttle valve (8), the temperature of the controller (14), the speed of the first water pump (10), the opening of the water circuit regulating valve (11), the flow rate, temperature, and pressure of the cooling water before the cooling controller (14), the temperature and pressure of the cooling water after the cooling controller (14), the temperature and pressure of the cooling water after the cooling air compressor (4), and the speed of the second water pump (19); The host computer (21) obtains in real time through the controller (14) the flow rate of the intake end gas of the air compressor (4) collected by the intake end air flow meter (2), the temperature and pressure of the intake end gas of the air compressor (4) collected by the intake end temperature and pressure integrated sensor (3), the temperature and pressure of the exhaust end gas of the air compressor (4) collected by the exhaust end temperature and pressure integrated sensor (5), the temperature and flow rate of the gas cooled by the intercooler (6) collected by the exhaust end air flow / temperature meter (7), the opening of the throttle valve (8), the temperature of the controller (14), the first water pump The speed of the cooling water pump (10), the opening of the water regulating valve (11), the flow rate of the cooling water in front of the cooling controller (14) collected by the electromagnetic flowmeter (12), the temperature and pressure of the cooling water in front of the cooling controller (14) collected by the temperature-pressure integrated sensor (13) at the front end of the controller, the temperature and pressure of the cooling water after the cooling controller (14) collected by the temperature-pressure integrated sensor (15) at the rear end of the controller, the temperature and pressure of the cooling water after the cooling air compressor (4) collected by the temperature-pressure integrated sensor (16) at the rear end of the air compressor, and the speed of the second water pump (19).

4. The method according to claim 1 The optimized design method of the fuel cell centrifugal air compressor analyzed is characterized in that: In step 2, the performance parameters include speed, throttle opening, mass flow, temperature, pressure and pressure ratio.

5. The method according to claim 1 The optimized design method of the fuel cell centrifugal air compressor analyzed is characterized in that: Step 3 specifically comprises: first, based on the structural parameters of the centrifugal air compressor in step 2, establishing a geometric solid model of the centrifugal air compressor using 3D modeling software, then meshing the geometric solid model of the centrifugal air compressor into discrete small units for numerical calculation; Then, the solver and boundary conditions are set in the CFD software to obtain the numerical calculation model of the centrifugal air compressor.

6. The method according to claim 5 The optimized design method of the fuel cell centrifugal air compressor analyzed is characterized in that: In step 3, the structural parameters include the geometric shapes of the impeller, diffuser, inlet and outlet ducts and volute, the number of blades, the inlet and outlet angles of the diffuser, whether the diffuser has blades or not, the size of the impeller blade tip clearance and the impeller inlet and outlet installation angles; The geometric entity model includes an impeller, an inlet and outlet duct, a volute and a diffuser; The solver uses the finite volume method, taking into account the movement of fluid and heat conduction; The boundary conditions include: the inlet is set as a pressure inlet, the outlet is set as a mass flow outlet, the inlet flow is monitored, and the difference between the inlet and outlet flow rates is used as the criterion for judging the convergence of the simulation.

7. The method according to claim 1 The optimized design method of the fuel cell centrifugal air compressor analyzed is characterized in that: In step 5, the maximum fitting error is the absolute value of the difference between the pressure ratio test value and the pressure ratio simulation value divided by the pressure ratio test value.

8. The method according to claim 1 The optimized design method of the fuel cell centrifugal air compressor analyzed is characterized in that: In step 6, the field quantity data include temperature, specific enthalpy h and specific entropy s; Calculated based on field data The specific value is: According to thermodynamics theory, the value of each node in the system is The value is calculated by formula (1): E=m[(h-h0)-T0(s-s0)] [1] In formula (1), m is the mass flow rate of the node; h is the specific enthalpy; s is the specific entropy; T0 is the thermodynamic temperature of the environment (K); and the subscript 0 represents the state of the environment.

9. The method according to claim 1 The optimized design method of the fuel cell centrifugal air compressor analyzed is characterized in that: In step 7, the centrifugal air compressor obtained in step 6 is heated by a thermal cycle method. Analyze the model and propose Analysis model There are two ways to classify loss E: E=E AV +E UN E=E EN +E EX (2) In formula (2), E AV To avoid Loss, E UN For the inevitable Loss, E EN For internal Loss, E EX For external loss; The specific extension is: combine the two classification methods of formula (2) to obtain a more detailed Classification of loss E: E=E EN,AV +E EN,UN +E EX,AV +E EX,UN (3) In formula (3), E EN,AV Avoidable internal Loss; E EN,UN Inevitable for internal Loss; E EX,AV Externally avoidable Loss; E EX,UN Unavoidable external loss; Quantification is the process of converting internal avoidable Loss E EN,AV Quantified as irreversible heat transfer, adiabatic throttling, fluid mixing and external leakage.

10. The method according to claim 1 The optimized design method of the fuel cell centrifugal air compressor analyzed is characterized in that: The method further comprises the steps of: Step 9: Follow the steps in step 8 to meet the minimum The numerical calculation model corresponding to the structural parameters of the centrifugal air compressor with loss and maximum efficiency is used to manufacture the corresponding centrifugal air compressor; Step 10: According to the method of step 2, the centrifugal air compressor obtained in step 9 is placed on the test platform of step 1 for testing to obtain test values ​​of performance parameters of the centrifugal air compressor; Step 11: Calculate the efficiency of the centrifugal air compressor based on the test values ​​of the performance parameters of the centrifugal air compressor obtained in step 10 to obtain the calculated value of the efficiency; if the error between the calculated value of the efficiency and the maximum efficiency obtained in step 8 is ≤10%, the optimization is completed; if the error is greater than 10%, return to step 8 and re-optimize to obtain a new value that satisfies the minimum efficiency. Structural parameters of centrifugal air compressor with loss and maximum efficiency; In step 11 , the error is the absolute value of the difference between the calculated efficiency and the maximum efficiency in step 8 divided by the maximum efficiency in step 8 .

Images