Fuel cell centrifugal air compressor optimization design method based on advanced analysis

Abstract

The invention discloses a fuel cell centrifugal air compressor optimization design method based on advanced # imgabs0 # analysis, which comprises the following steps of: firstly, building a centrifugal air compressor performance test platform, then testing a certain centrifugal air compressor, establishing a numerical calculation model of the centrifugal air compressor and simulating, and then comparing and analyzing a test value and a simulation value of a performance parameter; after verification, a # imgabs 1 # analysis model and an advanced # imgabs 2 # analysis model of the centrifugal air compressor are established; finally, structural parameters of the centrifugal air compressor are modified, numerical calculation models of the centrifugal air compressor with different structural parameters are established, and simulation is carried out; and then a # imgabs3 # analysis model and an advanced # imgabs4 # analysis model with different structure parameters are established, and iterative optimization is performed on the structure parameters by taking simultaneous reduction of # imgabs5 # loss and improvement of efficiency as targets until the structure parameters of the centrifugal air compressor meeting the minimum # imgabs6 # loss and the maximum efficiency at the same time are obtained. From the perspective of energy loss, high-efficiency low-loss optimization of the centrifugal air compressor is realized by adopting advanced # imgabs7 # 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 are efficient, clean, and environmentally friendly, and are widely used in transportation, energy stations, and mobile power sources. In fuel cell systems, air compressors play a key role in providing gas supply and pressurization.

[0003] Engineering Thermodynamics The exergy concept provides a way to quantify energy losses, based on the second law of thermodynamics, and is used to assess 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 The structure of the loss is optimized to improve 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 sequence 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 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 technical problem to be solved by the present invention is 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, and obtain test values ​​of performance parameters of the centrifugal air compressor;

[0010] Step 3, according to the centrifugal air compressor of step 2, obtaining the structural parameters of the centrifugal air compressor, and then establishing a numerical calculation model of the centrifugal air compressor 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, comparing and analyzing 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, and obtain the centrifugal air compressor Analytical models;

[0014] Step 7: The centrifugal air compressor obtained in step 6 Analyze the model and then expand the analysis results. Internally 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 optimal 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. According to step 4, calculate the simulation values ​​of the performance parameters of the centrifugal air compressor with different structural parameters respectively. 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 compressors with different structural parameters. Analyze the model and study the effect of different structural parameters on the internal avoidable Loss E EN,AV The influence of 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 mounts 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 models 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 Analytical models and advanced Analytical model to reduce The purpose 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, realize 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 present invention can accurately point out the contribution of specific components to system performance, thereby obtaining avoidable The structure of the loss can be targeted at different Grading to achieve optimal structural design, while improving the efficiency of the air compressor and reducing energy loss.

[0020] (4) The fuel cell centrifugal air compressor performance test platform constructed by the present invention takes into account the cooling system and data processing system, and can automatically collect data and upload it to the host computer, and control the throttle opening, etc. through the host computer. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is the overall flow chart of the present invention;

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

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

[0024] Figure 4 It is a schematic diagram of a geometric solid model of a two-stage centrifugal air compressor according to Example 1 of the present invention;

[0025] Figure 5 This is a schematic diagram of a mesh model of a two-stage centrifugal air compressor after mesh division according to Example 1 of the present invention;

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

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

[0028] The present invention provides a method based on advanced The optimized design method of the centrifugal air compressor for fuel cells (hereinafter referred to as the method) is characterized in that the method comprises the following steps:

[0029] Step 1: Design and build a fuel cell centrifugal air compressor performance test platform (referred to as the test platform, such as Figure 2 shown);

[0030] Preferably, 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;

[0031] The first water cooling system is used to cool the high-power components of the controller 14 and the centrifugal air compressor 4, including a first water tank 9, a first water pump 10, a water circuit 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 gas compressed by the centrifugal air compressor 4, and includes an 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 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 centrifugal 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 centrifugal 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 / thermometer 7; the outlet of the exhaust end air flow / thermometer 7 is connected to the outside through a throttle 8;

[0034] The air filter 1 is used to filter the air entering the centrifugal air compressor 4; the air flow meter 2 at the intake end is used to measure the flow rate of the gas at the intake end of the centrifugal air compressor 4; the temperature and pressure integrated sensor 3 at the intake end is used to monitor the temperature and pressure of the gas at the intake end of the centrifugal air compressor 4; the temperature and pressure integrated sensor 5 at the exhaust end is used to monitor the temperature and pressure of the gas at the exhaust end of the centrifugal air compressor 4 (i.e., the gas compressed by the centrifugal air compressor 4); the intercooler 6 is used to cool the gas compressed by the centrifugal air compressor 4; the air flow / thermometer 7 at the exhaust end is used to measure the temperature and flow rate of the gas cooled by the intercooler 6; the throttle 8 is used to adjust the gas flow rate discharged from 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 adjust the flow rate of cooling water in the first water cooling system; the electromagnetic flowmeter 12 is used to measure the flow rate of cooling water before the cooling controller 14; the temperature and 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 and 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 and 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 then the cooling water is 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 circuit 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 of the throttle 8, and the opening of the water circuit regulating valve 11; the operation interface can display the flow rate, 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 of the throttle 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 centrifugal air compressor 4, and the speed of the second water pump 19.

[0040] Preferably, in step 1, the host computer 21 obtains in real time through the controller 14 the flow rate of the intake end gas of the centrifugal air compressor 4 collected by the intake end air flow meter 2, the temperature and pressure of the intake end gas of the centrifugal 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 centrifugal air compressor 4 collected by the exhaust end temperature and pressure integrated sensor 5, the temperature and flow of the gas after cooling by the intercooler 6 collected by the exhaust end air flow / thermometer 7, the opening of the throttle 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 of the cooling water before the cooling controller 14 collected by the electromagnetic flowmeter 12, the temperature and pressure of the cooling water before the cooling controller 14 collected by the temperature and 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 and pressure integrated sensor 15 at the rear end of the controller, the temperature and pressure of the cooling water after the cooling centrifugal air compressor 4 collected by the temperature and pressure integrated sensor 16 at the rear end of the air compressor, and the speed of the second water pump 19.

[0041] Preferably, in step 1, the upper computer 21 controls the rotation 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 opening of the water circuit regulating valve 11 through the controller 14 to regulate the flow of cooling water in the first 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 first radiator 17 to control the temperature of the cooling water in the first water cooling system to be maintained within a reasonable range and does not exceed the set value.

[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 gas at the exhaust end 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 cooled 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, and 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, and 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, obtaining the structural parameters of the centrifugal air compressor, and then establishing a numerical calculation model of the centrifugal air compressor according to the structural parameters;

[0046] Preferably, step 3 specifically comprises: according to the structural parameters of the centrifugal air compressor in step 2, firstly establishing a geometric solid model of the centrifugal air compressor through three-dimensional modeling software, and then meshing the geometric solid model of the centrifugal air compressor, dividing it into discrete small units for numerical calculation; and 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 duct, a volute and a diffuser.

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

[0050] Preferably, in step 3, 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 inlet and outlet flow difference is used 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 grid division 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, and obtain 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 the theory of thermodynamics, the 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 environmental state.

[0062] Step 7: The centrifugal air compressor obtained in step 6 Analyze the model and then expand the analysis results. Internally 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 methods to Analyze the model to study the internal structure of centrifugal air compressor Loss E EN The distribution pattern of The degree of loss and energy consumption contribution can be optimized Losses are internally avoidable Loss E EN,AV and quantify it;

[0063] Preferably, in step 7, a thermal cycle method is used to heat the centrifugal air compressor obtained in step 6. The analytical model is analyzed and the Analytical Model There are two ways to classify the 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, which represent those losses that cannot be eliminated even with the most advanced technology and without considering costs, are inherent in the system and are closely related to the physical characteristics of the components and the operating conditions; 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 specifically: combining 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 for 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 For internal inevitable Loss is an irreversible loss inherent in the component and cannot be avoided even if the component works under optimal conditions; E EX,AV Avoidable for external Losses can be reduced by optimizing the structural parameters of other components or parts in the system. Loss; E EX,UN Externally inevitable Losses that cannot be reduced even if other components or parts in the system are working under 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. According to step 4, calculate the simulation values ​​of the performance parameters of the centrifugal air compressor with different structural parameters respectively. 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 compressors with different structural parameters. Analyze the model and study the effect of different structural parameters on the internal avoidable Loss E EN,AV The influence of Loss E EN,AV The structural parameters that have an impact; then a multi-objective optimization algorithm is used for the structural parameters that have an impact, and the optimization objective is to minimize 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 obtain 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 carried on the test platform of step 1 for testing to obtain the test values ​​of the performance parameters of the centrifugal air compressor;

[0075] Step 11, calculate the efficiency of the centrifugal air compressor according to the test value of the performance parameter of the centrifugal air compressor obtained in step 10, and 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 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 two-stage centrifugal air compressor for a fuel cell.

[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 at different speeds, and the inlet and outlet pressures and temperatures are recorded at each speed and mass flow rate of 0.06kg / s, 0.075kg / s, 0.09kg / s, 0.105kg / s, 0.12kg / s, 0.135kg / s, and 0.15kg / s, respectively. The data is 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 is processed to obtain the test values ​​of the performance parameters of the centrifugal air compressor, such as Figure 3 As shown, Figure 3 The pressure ratio-mass flow characteristic curve in the test results of a two-stage centrifugal air compressor is shown in FIG.

[0080] In step 3, the numerical calculation model of the centrifugal air compressor is established by first establishing a geometric solid model of the centrifugal air compressor through a three-dimensional modeling software according to the structural parameters of the centrifugal air compressor in step 2, and then meshing the geometric solid model of the centrifugal air compressor (such as Figure 5 As shown), it is divided into discrete small units; then the solver and boundary conditions are set in the CFD software to obtain the numerical calculation model of the centrifugal air compressor;

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

[0082] The boundary conditions include: the inlet of the low-pressure air compressor is set to atmospheric conditions, the temperature is room temperature 298K; the outlet of the high-pressure air compressor is set to mass flow. When analyzing the high-pressure stage alone, the inlet pressure of the high-pressure air compressor is set to the average total pressure of the outlet of the low-pressure air compressor, the temperature is the average total temperature of the outlet of the low-pressure air compressor, and the outlet is set to mass flow to ensure that the mass flow of the high-pressure and low-pressure air compressors is consistent. The solid wall is set to an adiabatic no-slip boundary, and the corresponding speeds of the rotor blades and the hub are set, and the remaining walls are stationary walls.

[0083] In step 5, Table 1 is a comparison of the pressure ratio characteristics of the simulation results and the test results of the two-stage centrifugal air compressor of Example 1 at 80000rpm, and the data are the pressure ratios when the mass flow rates are 0.06kg / s, 0.075kg / s, 0.09kg / s, 0.105kg / s, 0.12kg / s, 0.135kg / s, and 0.15kg / s, respectively, at a speed of 80000rpm. It can be seen from Table 1 that the maximum fitting error between the simulation value and the test value is less than 8.85%, verifying the accuracy and reliability of the numerical calculation model of the centrifugal air compressor obtained in step 3.

[0084] Table 1

[0085]

[0086] In step 7, quantizing the internal 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 the high-pressure air compressor have been 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 centrifugal air compressor for fuel cells 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, and obtain test values ​​of performance parameters of the centrifugal air compressor; Step 3, according to the centrifugal air compressor of step 2, obtaining the structural parameters of the centrifugal air compressor, and then establishing a numerical calculation model of the centrifugal air compressor according to the structural parameters; Step 4: Perform simulation on the numerical calculation model obtained in step 3 to obtain simulation values ​​of performance parameters of the centrifugal air compressor; Step 5, comparing and analyzing 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, and obtain the centrifugal air compressor Analytical models; Step 7: The centrifugal air compressor obtained in step 6 Analyze the model and then expand the analysis results. Internally 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 optimal 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. According to step 4, calculate the simulation values ​​of the performance parameters of the centrifugal air compressor with different structural parameters respectively. 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 compressors with different structural parameters. Analyze the model and study the effect of different structural parameters on the internal avoidable Loss E EN,AV The influence of 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 centrifugal air compressor for fuel cells 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 comprises a first water tank (9), a first water pump (10), a water circuit regulating valve (11), an electromagnetic flow meter (12), a temperature-pressure integrated sensor (13) at the front end of the controller, a temperature-pressure integrated sensor (15) at the rear end of the controller, a temperature-pressure integrated sensor (16) at the rear end of the air compressor, and a first radiator (17); The second water cooling system is used to cool the gas compressed by the air compressor (4), and comprises 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 arranged 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 arranged 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 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 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 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 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); The water outlet of the intercooler (6) is in communication with the inlet of the second radiator (20); the outlet of the second radiator (20) is in communication with the water inlet of the second water tank (18); the water outlet of the second water tank (18) is in communication with the inlet of the second water pump (19); the outlet of the second water pump (19) is in communication with the water inlet of the intercooler (6); The upper 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 water circuit 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 centrifugal air compressor for fuel cells analyzed is characterized in that: In step 1, the operation interface of the host computer (21) can set the temperature of the gas at the exhaust end 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 gas at the intake end of the air compressor (4), the temperature and pressure of the gas at the exhaust end of the air compressor (4), the temperature and flow rate of the gas after being cooled by the intercooler (6), the opening of the throttle valve (8), the temperature of the controller (14), the rotation 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 rotation speed of the second water pump (19); The upper computer (21) obtains in real time through the controller (14) the flow rate of the gas at the intake end of the air compressor (4) collected by the air flow meter (2) at the intake end, the temperature and pressure of the gas at the intake end of the air compressor (4) collected by the temperature and pressure integrated sensor (3) at the intake end, the temperature and pressure of the gas at the exhaust end of the air compressor (4) collected by the temperature and pressure integrated sensor (5) at the exhaust end, the temperature and flow rate of the gas after cooling by the intercooler (6) collected by the air flow / temperature meter (7) at the exhaust end, the opening of the throttle valve (8), the temperature of the controller (14), and the first water pump The speed of the cooling water pump (10), the opening of the water circuit 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 centrifugal air compressor for fuel cells 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 centrifugal air compressor for fuel cells analyzed is characterized in that: Step 3 specifically includes: firstly establishing a geometric solid model of the centrifugal air compressor by using a three-dimensional modeling software according to the structural parameters of the centrifugal air compressor in step 2, and then meshing the geometric solid model of the centrifugal air compressor to divide it 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 based on advanced The optimized design method of the centrifugal air compressor for fuel cells 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 air duct, a volute and a diffuser; The solver uses the finite volume method, taking into account the movement of the 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 the simulation convergence.

7. The method according to claim 1 The optimized design method of the centrifugal air compressor for fuel cells 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 centrifugal air compressor for fuel cells 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 the theory of thermodynamics, the 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 environmental state.

9. The method according to claim 1 The optimized design method of the centrifugal air compressor for fuel cells analyzed is characterized in that: In step 7, the centrifugal air compressor obtained in step 6 is treated 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 for internal Loss; E EN,UN For internal inevitable Loss; E EX,AV Avoidable for external Loss; E EX,UN Externally inevitable loss; Quantification is the 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 centrifugal air compressor for fuel cells analyzed is characterized in that: The method further comprises the steps of: Step 9: Follow the steps in step 8 to obtain 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 carried on the test platform of step 1 for testing to obtain the test values ​​of the performance parameters of the centrifugal air compressor; Step 11, calculate the efficiency of the centrifugal air compressor according to the test value of the performance parameter of the centrifugal air compressor obtained in step 10, and 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 Structural parameters of centrifugal air compressors with losses 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 .

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